REPORT OF THE FILTRATION COMMISSION OF THE CITY OF PITTSBURGH, PENNSYLVANIA, JANUARY, 1899. C. C. No. 406. Whereas, Recent advancement in sanitation is in the direction of agitation for the filtration of public water supplies to remove the pollution, which comes from the increase of population along the banks of the supplying streams ; and, Whereas, Investigations and experiments in this direction, while limited in practical operations to but one city in this country, have, nevertheless, progressed far enough to command tne careful consideration of a progressive city such as Pittsburgh; therefore, Resolved, That a commission be created, of which the Mayor of the city and the Presidents of the Councils and eight representative citizens and tax payers to be appointed by the Mayor shall be members, at least two of whom shall be physicians of recognized standing: Resolved further, That it shall be the duty of this commission to thoroughly investigate as to the character of our present water supply in its relation to public health, the effect of sand filtration and the advisability of establishing a sand filtra- tion plant for the city of Pittsburgh, with an estimate of the cost of establishing and maintaining the same; and also to investigate the feasibility and advisability of seeking other sources of supply. And the commission shall report its findings and recommendations together with such evidence as may be useful for the guidance of these Councils in acting prudently and for the best public interest in this matter. In Councils, June 8, 1896; Rule suspended, read three times and finally passed. Attest : E. J. Martin, Clerk of Select Council. Mayor's Office, June 10, 1896. Approved : H. P. Ford, Mayor. Attest : Geo. H. Welshons, Mayor's Clerk. TABLE OF CONTENTS. Page. Resolution, iii Table of Contents, v Report of Filtration Commission:- Scope of Investigations and Organization, i Character of the Present Water Supply in Relation to Public Health 3 Effect of Sand Filtration, 3 Advisability of Establishing a Sand Filtration Plant, 4 Cost of Establishing and Maintaining a System of Sand Filtration, 6 Feasibility and Advisability of Seeking Other Sources of Supply, 6 Conclusion, 7 Report upon the Sources of Typhoid Fever in Pittsburgh, by Prof. Wm. T. Sedgwick:- Introduction, n The Sources of Typhoid Fever in Cities,- Atmospheric Dust, 12 Infected Uncooked Food, 12 Secondary Infection or Contagion, 13 Ice Supply, 14 Milk Supply 14 Public Water Supply, 14 The Water Supply Derived from the Monongahela River, 15 The Water Supply Derived from the Allegheny River, 16 The Allegheny River is a Rapid Stream with little or no Opportunity for Self-Purification, 18 Distribution of Typhoid Fever in Pittsburgh, 22 The Allegheny River not the only Polluted Water Supply of Pittsburgh, 23 Summary and Conclusion, 23 Report of the Consulting Engineer, Allen Hazen, C. E.:- Introduction 27 Sanitary Condition of the Present Water Supply, Drawn from the Allegheny River,.... 30, Sanitary Condition of the Water Supplied to the South Side from the Monongahela River, 32 Average Composition of Allegheny and Monongahela River Waters 33 Muddiness, 34 Nature of Filtration, 36 Experiments upon Filtration, 37 Results from Experimental Filters,- Summary of Results from Sand Filters by Months, 39 Composition of Allegheny River Water before and after Settling, and after Passing through Sand Filters, 39 Summary of Results from Mechanical Filters by Months, 40 Composition of Allegheny River before and after Passing Mechanical and Sand Filters, 43 Results with Sand Filters,- Necessity of Preliminary Sedimentation, 44 Necessity of Covering Filters 44 Effect of Mud, Crude Petroleum, Mine Waste, etc., 45 Frequency of Scraping, 47 TABLE OF CONTENTS. VI PAGE. Results with Mechanical Filters,- Wasting Effluent after Washing,... -. 49 Influence of Amount of Sulphate of Alumina on Bacterial Efficiency, 5° Influence of Degree of Turbidity upon Bacterial Efficiency, 52 Influence of Number of Bacteria in Raw Water upon Bacterial Efficiency, 54 Average Results Obtained with various Quantities of Sulphate of Alumina, 54 Amount of Sulphate of Alumina Required to Clarify Turbid Waters, 55 Amount of Sulphate of Alumina which must be Used, 55 Action of Sulphate of Alumina and the Quantity of Sulphate of Alumina which can be safely Used, 56 Comparison of the Qualities of Effluents Obtained by Sand and Mechanical Filtration,- Bacterial Efficiency, 60 Clearness of Effluent, 61 Color, 62 Hardness, 62 Boiler Tests, 63 Cost of Construction of Filters, 64 Cost of Maintenance, 66 Final Comparison, Sand and Mechanical Filters, 68 Necessity of a Storage Reservoir for Raw Water, 68 Other Methods of Filtration Considered, 69 Auxiliary Supply of Unfiltered Water for Manufacturing Purposes, 71 Amount of Water to be Provided and the Restriction of Waste 73 Cities which have Adopted the Meter System, 76 Equitable Basis for Meter Rates, 77 Cost of Installing Meter System, 78 Supply of the South Side with Filtered Water, 79 Gravity Sources:- • Indian Creek, 81 Chief Features of the Project, 81 Quantity of Water, 81 Quality of Water, 82 Difficulties with Coal Lands, 82 Cost of Work 82 Comparison of the Cost of a Gravity Supply and the Present Supply Filtered, 82 Comparison of Costs Tabulated, 84 Conclusionsand Recommendations, 85 Report upon a Gravity Water Supply from Indian Creek, by Emil Kuichling, C. E.:- Source, g9 Available Quantity, 9I Consumption, Storage Reservoir and Dam, Tunnel Conduit, 8 Steel Pipe Conduits, Intermediate Structures on Pipe Conduits, IOI Estimated Cost, _ ' 102 Operating Expenses and Maintenance, IO3 Conclusion, ' 105 Report of the Resident Engineer, Morris Knowles, C. E.; Chapter I,-General Outline of the Work:- Organization, ? Sand Filters, Mechanical Filters 10 Worms Tile Filter, Berkefeld Filter,.. 111 112 TABLE OF CONTENTS. VII PAGE. Surveys, 112 Gravity Supply, 113 Miscellaneous Studies, 113 Pollution Investigations, 114 Experimental Filter Plant, 114 Boiler Experiments, 115 Asbestos, 115 General, 115 Title of Chapters and Appendices 117 Chapter II,-Sand Filter Experiments:- Description, 117 Operations, 119 Cracks in Filter Walls,. 120 Methods, 120 Analyses of Sand, 121 Dissolved Oxygen, 123 Bacterial Efficiency after Scraping, 124 Tabulation of Results by Months, 126 Chapter III,-Warren Filter Experiments:- Description, 155 Settling Basin, 155 Coagulant, 156 Filter, 156 Washing, 157 Agitator, 158 General, 158 Operations, 159 Composition of Coagulant, 159 Variations in the Rate of Filtration and in the Application of Coagulant, 160 Bacterial Efficiency after Washing, 166 Special Experiment to Show the Effect of Using different Quantities of Coagulant, .... 169 Tabulation of Results by Months, 171 Chapter IV,-Jewell Filter Experiments:- Description, .. 180 Settling Basin, 180 Coagulant, 180 Filter 180 Washing, 181 Agitator, 182 Operations, . 182 Sand Used, 183 Variations in the Rate of Filtration and in the Application of Coagulant, 183 Bacterial Efficiency after Washing, 187 Mechanical Effect of Trailing 189 Bacterial Efficiency after Trailing, 190 Effect of Cleansing with Soda Ash 191 Special Experiments to Show the Effect of Using different Quantities of Coagulant, ... 191 Tabulation of Results by Months, 193 Chapter V,-Worms Tile Filter Experiments:- Description, 202 Coagulating Solution and Apparatus, 202 Scrubbers, 202 Filter Tanks and Tiles, 203 Washing, 203 Operations, 204 VIII TABLE OF CONTENTS. PAGE. Breakage of Tiles, 2°4 Bacterial Efficiency after Washing, 2O5 Tabulation of Results by Months, 206 Chapter VI,-Boiler Experiments:- Description, 216 Tabular Statement of Dimensions, 216 Formation of Scale,... 217 Conclusion, 219 Appendix No. 1, Methods of Chemical Analyses and Discussion of Results, by Dr. Walther Riddle; Part I, Methods:- Collection of Samplesand Preliminary Examination, 225. Turbidity and Sediment, 225 Color, 225 Nitrogen as Ammonia, .' 226 Nitrogen as Nitrites, 227 Nitrogen as Nitrates, 22& Chlorine 228 Residue on Evaporation, 229 Loss on Ignition, 229 Hardness, 230 Alkalinity, 230 Sulphuric Acid, 230 Iron, 231 Alumina, , 231 Dissolved Oxygen, . 232 Part II,-Discussion, ■ ■ 232 Appendix No. 2, Description of Sources of Samples and Results of Chemical Analyses, also Number of Bacteria Per Cubic Centimeter:- Introduction, 237 Allegheny River at Brilliant, 237 Pittsburgh City Tap, 244 Gate Chamber, 24& Settling Basin, 2$o Effluents-Sand Filters 25, Effluent-Warren Filter, 26o Effluent-Jewell Filter, ■ 26 Applied Water-Worms Tile Filter, • 26- Settled Water- " " " ,, _ „ 200- Effluents- « « « 268 Monongahela River,-at Intake of Monongahela Water Company, 270 South Side Tap, ... Allegheny River at Montrose, ?g Effluent-Montrose Crib, / a8o Allegheny City Tap, \ 2 ° Allegheny River at Hulton, 22 Effluent-Hulton Crib, ' " ' 2 5 Verona Tap, 27 Allegheny River at Wildwood, 289 Effluent-Wildwood Crib, 292 Wilkinsburg Tap 294 Effluent-Sharpsburg Crib, 29$ Allegheny River at Etna, 298 Effluent-Etna Crib, 299 Etna Tap, //.../ 301 ' Allegheny River at Millvale,. 304 305 TABLE OF CONTENTS. IX PAGE. Effluent- Bennett Water Company Crib, Millvale, 306 Millvale Tap 3°9 Ohio River at Sewickley, 310 Effluent-Sewickley Crib, 311 Sewickley Tap, 311 Tap in Department of Public Safety Building, before Filtration, 312 Tap in Department of Public Safety Building, after Filtration, 313 Water in Experimental Boilers, 314 Driven Well at Brilliant, 316 Howe Spring, 316 Well at McConway-Torley Manufacturing Company, 317 Well at Sligo Mills, 318 Miscellaneous City Samples, 1 318 Miscellaneous Suburban Samples, 320 Indian Creek and Vicinity, 321 Appendix No. 3, Bacteriological Investigation of Fifteen Samples of Pittsburgh City Water, by Eugene Wasdin, M. D.:- 327 Tabulation of Results, 330 Appendix No. 4, Report upon Bacteriological Investigations, by Wm. R. Copeland:- Introduction, 333 Part I,-Methods Employed to Determine the Numbers of Bacteria in Water, 334 Plating, 335 Temperature, 336 Number of Days during which Plates were Allowed to Develop, 338 Reaction of Media, 339 Table of Temperatures in Thermostat,. . 342 Part II,-Species of Bacteria, 344 Species of Bacteria Found in the Allegheny River Water before and after Filtration,... 344 Application of Bacillus prodigiosus, 345 Species of Bacteria Found in Samples of Allegheny River Water, 346 Tests for Bacillus coli communis, 348 Tabulation of Results, 348 Part III,-Micro-Organisms, 349 Gate Chamber, 350 Settling Basin, 350 Effluents, 350 Highland Reservoir, 350 Herron Hill Reservoir, 351 Bedford Basin,...' 351 South Side Reservoir, 351 Wilkinsburg Reservoir,... / 351 Tabulation of Results, 352 Appendix No. 5, Report upon Driven Well Supply, by A. B. Shepherd, Supt., 360 Appendix No. 6, Financial Statement, 361 Index, 363 LIST OF MAPS, PLANS, AND DIAGRAMS. Plate No. . Page. 1. Reported Number of Cases of Typhoid Fever, in each Ward of Pittsburgh, 1892-1897, 22 2. Location of Reported Cases of Typhoid Fever in Pittsburgh in 1897, 24 3. Water-Shed of Allegheny River, 30 4. Water-Shed of Monongahela River, 32 5. Average Monthly Temperatures at Pittsburgh, January, 1887, to September, 1898, 34 6. Monthly Precipitations at Pittsburgh, January, 1888, to September, 1898, 36 X TABLE OF CONTENTS. Plate No. page. 7. Bacterial Efficiencies of Mechanical Filters, with various Quantities of Sulphate of Alumina, 52 8. Amounts of Sulphate of Alumina actually Used with Mechanical Filters with Water of various Degrees of Turbidity and the Amounts necessary for Clar- ification, 56 9. Location of Filters and Land, Included in Estimates of Cost, 66 10. Estimated Consumption of Water with and without Meters and Comparison of Annual Charges of Present Supply Filtered with a Gravity Supply, 84 11. Proposed Indian Creek Reservoir and Conduit to Pittsburgh, 100 12. General Plan of Experimental Filter Plant, 114 13. General Plan of Filter Building, 116 14. Plan and Section of Sand Filters, 118 15. Plan of Warren Filter, I56 16. Elevation of Warren Filter, I36 17. Plan of Jewell Filter, 182 18. Elevation of Jewell Filter T82 19. Plan of Worms Tile Filter, 2O4 20. Elevation of Worms Tile Filter, 2O4 21. Test Well at Brilliant Pumping Station, 36o To the Presidents and Members of the Select and Com- mon Councils of the City of Pittsburgh : Gentlemen:- In pursuance of the authority given by an ordinance approved June to, 1896, the undersigned were appointed as an investigating body, charged with the following duties:- 1. To thoroughly investigate the character of the present water supply of the city of Pittsburgh in its relation to public health. 2. To ascertain the effect of sand filtration. 3. To ascertain the advisability of establishing a sand filtration plant for the city of Pittsburgh. 4. To present an estimate of the cost of establishing and maintain- ing the same. 5. To investigate the feasibility and advisability of seeking other sources of supply. 6. To report its findings and recommendations, together with such evidence as may be useful for the guidance of the Councils of the city of Pittsburgh, in acting prudently and for the best public interest in this matter. The constitutionality of the legislation under which we had been ap- pointed having been affirmed by the proper legal authorities, an organiza- tion was effected on July 6, 1896, by the election of Mr. Robert Pitcairn as Chairman, Mr. William McConway as Vice-Chairman, and Mr. Geo. L. Holliday as Secretary. A committee upon Methods of Procedure, consisting of Dr. W. J. Holland, Chairman, Dr. J. R. Vincent and Hon. William Flinn, was ap- pointed at the first meeting, and, in accordance with the recommendations of this committee, certain phases of the questions proposed to us for con- sideration were assigned to the general oversight of special sub-commit- tees ; the Chairman appointing them as follows :- On Water Analysis; Dr. W. J. Holland, Chairman, Dr. J. Guy McCandless, Dr. J. R. Vincent. On General Information; Mr. William McConway, Chairman, Hon. H. P. Ford, Mr. Geo. L. Holliday. 2 REPORT OF FILTRATION COMMISSION. On Other Sources of Supply; Hon. Wm. Flinn, Chairman, Mr. E. M. Bigelow, Mr. S. D. Warmcastle, Mr. Jas. M. Bailey. As the result of frequent conferences and preliminary investigations it was decided that in order to carry out the instructions contained in the ordinance it would be necessary to employ the services of competent ex- perts to investigate, under the general direction of the Commission, the various problems which might present themselves. Accordingly, with the consent and sanction of your Honorable Bodies, the Commission secured the services of the following per- sons :-• As Consulting Engineer, Mr. Allen Hazen, of New York City. As Resident Engineer, Mr. Morris Knowles, of Lawrence, Mass. As Chemist, Walther Riddle, Ph.D., of the City of Pittsburgh. As Bacteriologist, Mr. Wm. R. Copeland, of Lawrence, Mass. Subsequently, as the necessity for increasing the force was shown, a number of other persons were employed to assist in the prosecution of the labor of investigation. The Commission has held seventy sessions, at which reports of pro- gress were regularly submitted by the Resident Engineer. Various questions coming up from time to time for consideration were discussed and reports were submitted, when called for, by the standing committees and by special committees, which were from time to time appointed. The Commission as a body, on November n, 1896, visited the city of Law- rence, Mass., for the purpose of inspecting the filtration beds in operation in that city, and on their return, devoted a day in the city of New York to the inspection of certain plants engaged in mechanically filtering private water supplies. On April 19 and 20, 1898, the Chairman of the Commission, accompanied by the Chairman of the Committee on Water Analysis, the Mayor of Pittsburgh, and the Resident Engineer, visited the cities of Louisville, Ky., and Cincinnati, Ohio, for the purpose of investigating the methods and results of the extensive ex- perimental plants established in these cities, and also visited the city of Covington, Ky., and examined the water works of that munici- pality. Availing themselves of the opportunities of foreign travel, several members of the Commission visited and carefully inspected filtration plants on the other side of the Atlantic. Mr. Wm.McConway visited the CHARACTER OE PRESENT WATER SUPPLY. 3 filtration beds and the sewage treatment plants of London, England. Hon. William Flinn visited the filtration plant of Hamburg, Germany. Dr. W. J. Holland visited the filtration plants of London, Paris, Antwerp, Bremen, Hamburg, and Berlin. Mr. E. M. Bigelow visited the filtration plant at Hamburg. All of these gentlemen reported to the Commission the results of their observations. The members of the Commission have borne all expenses involved in visits paid to other localities, whether in this country or abroad, without recourse to the funds placed at the disposal of the Commission. THE CHARACTER OF THE PRESENT WATER SUPPLY OF THE CITY OF PITTSBURGH IN ITS RELATION TO PUBLIC HEALTH. We find that the present water supply is objectionable, first on account of the mud which it frequently carries, and secondly, because of its pollu- tion by sewage. An ocular inspection of the Allegheny and Mononga- hela Rivers and their main tributaries, made under the direction of the Commission, reveals the fact that from the very summit of the mountains to the intakes all are more or less contaminated by sewage, and the re- ports of the Bacteriologist of the Commission show the presence of bac- teria in objectionable quantities, both in the river water and in the tap- water as delivered. ■ Your Commission has arrived at the conclusion that with the proper filtration of the water supplies furnished to the people, water-borne diseases, which are so prevalent in this community, would, undoubtedly, be greatly lessened. If, in addition, more stringent regulations against the sale of infected milk and ice were enacted and enforced, and the use of water from springs and wells and of unpurified supplies of water in mills and factories were prevented, they would be almost wholly eradicated, except as the result of secondary infection from cases imported into the community. THE EFFECT OF SAND FILTRATION. Elaborate experiments extending over a period of time of sufficient length to show the effects of filtration upon the water of the Allegheny River ih all seasons and at all stages have been carried on, as is detailed at length in the reports hereto appended, (See Exhibits 2, 4, and 5). These investigations show the entire feasibility of so treating the water by several methods as to remove both the mud and the deleterious vege- table growths contained therein. Of the various methods of filtration which have been examined two have proved themselves efficient, the method of mechanical filtration and the method of sand filtration. The latter, which has been extensively 4 REPORT OF FILTRATION COMMISSION. employed for many years past in Europe and also in this country, has yielded upon the whole somewhat better results than the former. As is fully set forth in the reports of the experts employed by the Commission, and as is shown in the tables which are thereto appended, the method of sand filtration not only yields a supply of water free from mud and objec- tionable bacterial life, but also furnishes a supply of water of a quality adapted to mechanical purposes, suited to the uses of industrial establish- ments. An investigation of this latter phase of the question was under- taken under the instruction of this body, and the results are hereto appended. (See Chapter VI, of Exhibit 4). THE ADVISABILITY OF ESTABLISHING A SAND FILTRATION PLANT FOR THE CITY OF PITTSBURGH. We find that it is in the highest degree desirable that the water sup- plied to a great municipality like Pittsburgh should be clear and free from objectionable matter, as well as of sufficient softness to permit of its use for domestic and mechanical purposes, and, as it is possible to furnish such a supply by one or the other of two methods the problem resolves itself into the question, which of the two is, on the whole, better adapted for the public service; taking into account:- (a) Comparative cost. (b) Efficiency. (c) Durability, as evidenced by its probable freedom from decay or wear and consequent necessity for repairs. (d) Simplicity of operation. Comparative Cost. If a conclusion were to be arrived at upon a consideration of initial cost, alone, the decision would doubtless be prompt. While the cost of bare construction differs but slightly as between the two plans, the cost of the larger body of land, required for the sand filtration plant, would be determinative, in favor of mechanical- filtration, were other things equal. Efficiency. An examination of the relative efficiency of the two methods, in the light of actual experiment, shows that so far as the removal of bacteria from the water is concerned the sand filter leaves but little to be desired. In addition to bacterial efficiency and somewhat important, is the ques- tion .of the adaptability of the effluent for steaming purposes. The effluent which yields a minimum scale formation, and shows no corro- sive action upon the points in a boiler generally first exposed to at- ADVISABILITY OF ESTABLISHING A SAND FILTBATION PLANT. 5 tack, is, all other things being equal, to be preferred. We find that the weight of evidence, obtained by experiment, is in favor of sand filtration ; so far as efficiency in this respect is concerned. Durability. There being in the sand filters practically no metallic material ex- cept valves and connecting piping, common to both systems, it may be said to be subject to deterioration only by actual abandonment; by de- cay, never. In some of the filtration plants, visited by members of this board, are found sections in operation and as sound as though built but yesterday, which have already done service for forty years, and bid fair to render efficient service for many times this period. No plant built un- der the plan of mechanical filtration could be expected to yield such re- sults. All mechanical devices are subject to rapid deterioration through wear and tear. It is generally assumed by careful manufacturers that the life of a machine in constant use does not exceed ten years. This being the case, the finding as to the question of durability is decidedly in favor of the system of sand filtration. Simplicity of Operation. In operating a plant of such magnitude as will be required to provide a full supply of pure water to this large and growing city it is of the first importance to do it on such lines as not to require, necessarily, the higher grades of technical skill on the part of a large proportion of the operatives. The sand filter meets this requirement to such an extent as .to be fairly considered ideal. When properly constructed, slight neglects and errors of judgment on the part of workmen cannot damage the water. With any filter using coagulant the conditions are different; nice judgment is required to determine from day to day, and at times from hour to hour, the required quantity of that coagulant, and if there be not the proper quantity of lime in the water, initially, that must also be provided. The report of the Consulting Engineer (Exhibit 2) presents the detail of the operation in such full form that your Commission thinks it proper to call your attention to this feature and urge a careful study of the same. The choice lies between a system, which, when properly constructed, cannot furnish impure water, except as the result of wilful neglect, and one which can furnish pure water, but which can also, when carelessly or ignorantly handled, easily produce water unfit for domestic or mechanical use. The weight of evi- dence is found by the Commission to be decidedly in favor of sand filtra- tion, so far as simplicity of operation is concerned. The facts that no patents and consequent charges on this account are to be met in case of the use of sand filters, is an additional consideration 6 REPORT OF FILTRATION COMMISSION. which has had weight with us in reaching a conclusion to recommend the use of sand filters. Finally the fact that the sand filters have been in sucessful use in England and on the continent of Europe for more than forty years and are employed by more than thirty of the great trans- atlantic municipalities; among them, being London, Berlin, Hamburg, Bremen, and the suburbs of Paris, with unvarying satisfaction, is a cir- cumstance which has had great weight with us. In view of all the foregoing considerations we find the adoption of the system of sand filtration to be the most advisable. the; cost of establishing and maintaining a system of sand filtration. We find that the cost of construction of sand filters with sedimen- tation basins and all accessories complete may be estimated at $1,691,000. To this should be added the cost of the necessary land. Should the land cost $420,000, the total estimated cost will be $2,111,000. The cost of maintenance in the case of sand filters with sedimentation basins, pro- viding 50,000,000 of gallons daily, would amount, according to the figures submitted by our Consulting Engineer, to $192,184, of a cost of $10.53 per million gallons. This estimate includes interest, depreciation, and all operating expenses. THE FEASIBILITY AND ADVISABILITY OF SEEKING OTHER SOURCES OF SUPPLY. The results of our investigation in reference to this matter are set forth in full in the report of the Consulting Engineer (Exhibit 2), and in the report of Mr. Emil Kuichling, C. E., of Rochester, N. Y. (Exhibit 3), who was employed to make a full examination into the feasibility of intro- ducing a water supply from the water-shed of Indian Creek. We find that the initial cost of introducing a supply from this source, which appears to be the most available of all sources of gravity supply, would be thirteen and a half millions of dollars, and the expense of the undertaking, together with the uncertainty of being able, except at a vast additional expense, of adding to this supply after the lapse of a comparatively short time, make the project one to which we cannot set the seal of our approval. Auxiliary Supply. We have examined into the question of furnishing a supply of potable water for household consumption separate from the supply furnished to mills and factories, but find that the consumption of water by the mills and factories is not great enough to justify the large expense that would be involved in providing pipes to convey separate supplies, CONCLUSION. 7 and we deem it, furthermore, eminently desirable, inasmuch as water is freely used in the mills and factories for drinking purposes, that the supply of water furnished these establishments should be of a good character from a sanitary standpoint. For these two reasons we cannot recommend a sparation of the two supplies. Use of Meters. We conclude as the result of careful investigations that the city is now wasting more than twice as much water as it uses. We find that the experience of other cities reveals that the introduction of a system of sale by meter has the result of greatly reducing the waste, and we strongly recommend the adoption of the meter system for the sale of waiter. We believe that the introduction of the use of meters will prevent waste to such a material extent as to greatly lessen the cost, alike of the establishment of a system of filtration and its subsequent operation, and possibly to make it feasible, from a plant of the size suggested in the report of the Con- sulting Engineer to supply, not only the portions of the city now using- water of the Allegheny, but those also which are drawing their supply from the Monongahela. Conclusion. We recommend, in conclusion, that the city of Pittsburgh adopt, for its water supply, the system of sand filtration upon the plan recommended herewith in the report of our Consulting Engineer, and that the system of selling water by meter be likewise adopted. For the erection of a filtra- tion plant approximately $i,700,000 will be required; to provide the neces- sary site $500,000 should be amply sufficient; to establish the meter system will require an additional outlay of $600,000. We recommend that your Honorable Bodies make provision for an issue of bonds for these purposes to the amount of $3,000,000, the bonds to be issued by the proper authori- ties as they may be required, and no more to be issued than are actually required to provide for the establishment of a system of filtering and meter- ing the water supplied to the city. In recommending an issue of bonds to the amount of $3,000,000 we have allowed $200,000 for contingencies, which might, but are unlikely to, arise, and we believe that the sums above named will be quite sufficient to make it sure that all the water supplied the municipality will be wholesome, as it certainly will be clear and free from mud. We append to our report the following papers :- 1. Report upon the Sources of Typhoid Fever in Pittsburgh, by Prof. William T. Sedgwick, Ph. D. 2. Consulting Engineer's Report, by Allen Hazen, C. E. REPORT OF FILTRATION COMMISSION. 8 3. Report upon a Gravity Water Supply from Indian Creek, by Emil Kuichling, C. E. 4. Resident Engineer's Report, by Morris Knowles, C. E. 5. Appendices to the Resident Engineer's Report, (Appendices 1-6). Respectfully submitted, Robt. Pitcairn, Chairman. William McConway, Vice Chairman. Geo. L. Holliday, Secretary. Henry P. Ford, Mayor. S. D. Warmcastle. J. R. Vincent. W. J. Holland. E. M. Bigelow. James M. Bailey. J. Guy McCandless. Wm. Flinn. REPORT UPON The Sources of Typhoid Fever IN PITTSBURGH. BY WILLIAM T. SEDGWICK, Professor of Biology and Lecturer on Sanitary Science, Massachusetts Institute of Technology; and Consulting Biologist, State Board of Health of Massachusetts. EXHIBIT I. Mr. Robert Pitcairn, Chairman, Filtration Commission ; Pittsburgh, Pennsylvania. Sir .- In accordance with your instructions, I have made a thorough investi- gation of the probable gources of typhoid fever in Pittsburgh, and have the honor to respectfully submit herewith a formal report upon the same I have followed as closely as possible in making this report the lines along which I proceeded in making a preliminary report to the Commis- sioners, when I personally appeared before them in September. It will appear from what follows that such investigations and studies as I have been able to make in the interval, support the conclusions and strengthen the opinions which I laid before the Commission at that time. TYPHOID FEVER HAS BEEN THE CAUSE OF MANY DEATHS AND IS CONSTANTLY PRESENT IN PITTSBURGH. The vital statistics of Pittsburgh show conclusively that typhoid fever has for many years been an important factor in the death rate of the city. During the past decade it has been the assigned cause of 2,245 deaths, an average of 224.5 deaths per annum. During these last ten years, and probably for a very much longer period, Pittsburgh has never been wholly free from typhoid fever, but on the contrary most of the time has contained a large number of cases; for at no time within the last ten years have there been fewer than four deaths per month attributed to this disease, while the monthly average has been very much larger, namely, 18.7 deaths. These figures mean that during the last decade there have been in the city of Pittsburgh very rarely, if ever, at any one time, fewer than one or tw7o score of cases of typhoid fever, while there has been on the whole a probable average of between 150 and 200 cases at any given time. It is Excessive in Amount. The average annual number of deaths in Pittsburgh during the last ten years (1888-1897) is 224.5 alld the (estimated) population in 1895 was 275,000. During the same period the average annual number in Boston was much smaller (158.9) with a population much larger, viz: in 1895, 496,620. For the same period in New York, the figures are: population in 1895; 1,669,801-the average number of deaths from typhoid fever per annum, 352.2 Otherwise stated this means a rate per annum per 100,000 inhabitants, of 21.0 in New York City, 31.9 in Boston, and 81.6 in Pitts- burgh. These figures show conclusively that the amount of typhoid fever THE SOURCES OF TYPHOID FEVER IN PITTSBURGH. 12 in Pittsburgh is excessive, and as I believe it is admitted on all sides that such is the fact, I shall not dwell further upon this aspect of the subject. THE SOURCES OF TYPHOID FEVER IN CITIES. It is now everywhere admitted that typhoid fever does not arise spontaneously but comes only from antecedent cases of the same disease from which it is conveyed in various ways to fresh victims. The medium of communication in these cases is often spoken of as the "vehicle" of the disease, and the following are some of the principal vehicles by which it is so conveyed: i. Water Supply. 2. Milk Supply. j. Ice Supply. 4. Secondary Infection or Contagion. 5. Infected Uncooked Food, such as Oysters, Vegetables, Fruits, etc. 6. Atmospheric Dust. Any or all of these vehicles may be the immediate sources of typhoid fever in a city; the remote source in all cases being understood to be the body of a patient affected with the disease. In searching for the causes of the excess of typhoid fever in Pittsburgh, we must naturally consider in detail each of these several possible sources, and we may do this taking them up in the reverse order to that in which they have just been enumer- ated. Atmospheric Dust. In any city in which typhoid fever is abundant it must be allowed that there may be a continuance of the disease for a time, owing to the causa- tion of a certain number of secondary cases through the medium of atmospheric dust, especially if disinfection is not very thoroughly carried out for the primary cases. The present state of our knowledge, however, in regard to the dis- semination of typhoid fever by means of dust is not such as to allow us to attribute to this source any considerable number of cases and we need not hesitate to dismiss this as in any great degree an adequate explanation of, although it may well be a contributory cause to, the sum total of typhoid fever in Pittsburgh. Infected Uncooked Food, (Oysters, Vegetables, Fruits, Etc.) It is generally held by sanitarians that uncooked food, especially such as has been handled by various people, and, in particular, raw oysters which may have been cultivated in sewage-polluted waters; lettuce which may have been watered with impure liquids; celery which may have been SOURCES OF TYPHOID FEVER. 13 manured with night-soil and afterwards imperfectly cleaned for the table; or fruits, such as cherries, grapes, apples, pears, peaches, berries and the like which are often handled by unclean persons and then eaten without having been thoroughly washed, may readily be vehicles of the germs of typhoid fever. I have not, however, been able to discover that Pittsburgh is peculiar in any of these respects (unless possibly it may be in the con- sumption of raw oysters brought from sources, the precise sanitary con- dition of which is not known), and I do not believe, therefore, than any considerable proportion of the total typhoid fever of Pittsburgh can be charged to these sources, although it should never be forgotten that they may be important contributory factors in a case like this and, in cities having only a small amount of the disease, may even be the principal factors. Special attention has lately been drawn by armv officials to the probable importance of flies as bearers of infection from, excreta to articles of food which are afterwards eaten raw; but even allowing this to be true it does not suffice to explain the peculiar state of affairs in respect to typhoid fever in Pittsburgh. Against the supposition that the food supply as described is respon- sible to any considerable extent for the typhoid fever in Pittsburgh is the notable fact that the cases appear to be, on the whole, quite evenly distributed according to population throughout the city. These facts do not support the view that the disease has its origin in infected foods, for any general infection of the entire food supply of the city cannot well be supposed to be constantly recurring. Secondary Infection or Contagion. It is otherwise as regards the part probably played by secondary in- fection or contagion. Contrary to the popular belief, typhoid fever is, in a true sense, a contagious disease, although far less so than the more eruptive diseases such as scarlet fever, measles, small-pox, and also prob- ably much less contagious than certain other diseases such as diphtheria. When, therefore, there is for any reason a considerable number of cases of typhoid fever in any city or town, it follows almost inevitably that there will be a considerable number of cases secondary to these and derived from them, which will form another important contributory factor in making up the sum total to be found during any considerable period. I have examined carefully the reports of cases on file in the Bureau of Health and have satisfied myself that Pittsburgh forms no exception to this general rule; for a considerable number of cases appear upon the books which are plainly secondary to other cases, and I am informed by prominent phy- sicians that such examples are by no means rare. This factor, however, like those which have alreadv been discussed, would, in itself, be of small 14 THE SOURCES OF TYPHOID FEVER IN PITTSBURGH. moment if there were no primary and more permanent causes making up the principal part of the total. Ice Supply. Although it is customary for sanitarians to turn to the ice supply of cities as an important source of typhoid fever, the latest and most trust- worthy investigations on this subject do not support the idea that any considerable number of cases, even in a large city using a comparatively impure ice supply, can be traced to this source, and it is a remarkable and important fact that no epidemic or other excess of typhoid fever has ever yet been indisputably traced to infected ice. Moreover, inasmuch as .artificial ice, made from distilled water, is almost exclusively used in Pitts- burgh for household purposes, it is altogether improbable that any excess of typhoid fever could come from this source; but, at the same time, as the use of pond or lake ice is not prohibited, it is very likely that the latter is used occasionally. Accordingly, while it is possible that a few out of the large number of cases in Pittsburgh can be charged to this source, I do not believe that any considerable number has come from impure ice and we may properly consider this factor as perhaps con- tributory to. but cannot possibly regard it as the principal cause of, the large amount of typhoid fever constantly present in Pittsburgh. Milk Supply. Within the last score of years a large number of cases of typhoid fever in various parts of the. world have been traced in the most positive manner to polluted and infected milk supplies, and no fact in sanitary science is better established than that milk infected with typhoid fever is not only comparatively speaking, common, but also highly effective as a vehicle of this disease. I have inquired carefully in regard to the milk supply of Pittsburgh, and I am of the opinion that in all probability a certain amount of the typhoid fever which prevails in this city, and has prevailed for many years, may reasonably be attributed to infected milk. At the same time, epidemics due to infected milk are always occasional and sporadic, not constant and general, and it is a well-known character- istic of typhoid fever due to milk supplies that the disease appears in special areas with marked violence only for a limited time. It is, therefore, quite clear that while the milk supply may have been, and probably has been, an important contributory cause to the sum total of typhoid fever in Pittsburgh, it is manifestly not the principal cause, which must be something constant and general, instead of occasional and sporadic. The Public Water Supply. There remains for consideration only one important source of typhoid fever in cities, namely, the public water supply; and, inasmuch as by ex- THE PUBLIC WATER SUPPLY. 15 elusion we have determined that the other principal sources of typhoid fever in cities are here inadequate to furnish any sufficient explanation of the typhoid fever which is so constantly and so excessively prevalent in Pittsburgh, we shall need to give to the public water supply the most careful consideration. It is well known to your Honorable Board that Pittsburgh is provided with two principal sources of supply, namely, the Allegheny and Mononga- hela Rivers, and that most of the supply is derived from the Allegheny. In both cases the water which is delivered to the citizens is drawn directly from the river without filtration or other purification of any sort, then immediately pumped to distributing reservoirs and from these quickly sent all over the city. From the standpoint of modern sanitary science, this procedure is prima facie most objectionable, inasmuch as the delivery to the people of unpurified river water is nowadays everywhere regarded as extremely dangerous, such water has been too often found to be a fruitful source of typhoid fever and kindred diseases. In the present instance, however, it will not suffice to rely simply on the facts just stated, straight- way concluding that we have in the public water supply an all-sufficient explanation of the constant and excessive amount of typhoid fever in Pittsburgh. We cannot indeed escape the natural suspicion that this may be true; but before coming to any final conclusion in regard to a matter necessarily so complex and obscure as the sources of typhoid fever in a great city, we must first examine closely all the evidence in hand, and especially local conditions, in order to verify any preliminary conclusions which may be reached; and this all the more, because such conclusions may involve important changes in public policy and the expenditure of large sums of public money. THE WATER SUPPLY DERIVED FROM THE MONONGAHELA RIVER. The water of the Monongahela River is used by a limited portion only of the city, namely, that lying upon the south side of the same river and including wards Twenty-four to Thirty-eight inclusive, with the exception of ward Thirty-seven. The total estimated population of these wards for 1897 is about 78,000, that is to say, about one-fourth of the whole population. In addition to the urban population using this water, it is fur- nished to about twenty-five thousand people living in the boroughs immediately adjacent to the city. The Monongahela River and its upper affluents, rising in the exten- sive forests of West Virginia, flows for the greater part of its course though a sparsely inhabited region, and, owing to the fact that it has been slack-watered over almost its entire course, the process of sedimentation goes on extensively, so that it might furnish an admirable water supply 16 THE SOURCES OE TYPHOID FEVER IN PITTSBURGH. were it not for the fact that in its lower reaches it is heavily contaminated by sewage. The sewers of the city of McKeesport, of the boroughs of Homestead, Braddock, Duquesne, and other lesser places, all empty into the river above the intake of the Monongahela Water Company, and as the growth of the population in these towns and city is rapidly in- creasing, it is presumable that the amount of sewage emptied into the Mo- nongahela River is destined likewise to increase. I am of the opinion that the general use of this contaminated water is in itself alone an adequate explanation of the great amount of typhoid fever which has at times prevailed on the South Side. This conclusion is confirmed by the results obtained by the Bacteriologist of your Commission, Mr. Wm. R. Copeland, who has found repeatedly in his examinations of the tap water derived from the Monongahela, as well as in the river itself, large numbers of bacteria. Inasmuch, therefore, as micro-organisms abound in the river water, the latter is presumptively the ready vehicle for the specific germs of typhoid fever which we have every reason to believe enter the river from time to time with the sewage which it so freely receives in its lower reaches. In the absence of any other adequate explanation for the typhoid fever constantly recurring on the South Side, and in the presence of a simple and sufficient explanation in the consumption by the people of river water unpurified and polluted with sewage, I have no hesitation in affirm- ing that it is probably the water supply which is the principal source of the typhoid fever of the South Side. Furthermore, we must not overlook the fact that when any part of a community is supplied with infected water, other parts, and possibly all parts, may also suffer from it. If, for example, a dweller on the north side works in a mill or a house on the South Side, or even onlv visits there, he or she may, by drinking infected water on that side, become infected and, returning home, not only suffer from the disease but also become a center of infection and cause others on the north side to suffer likewise. THE WATER SUPPLY DERIVED FROM THE ALLEGHENY RIVER. In the case of the Allegheny, which supplies the' principal portion of Pittsburgh, namely, that part of it lying between the two rivers and includ- ing the great mass of the population, the case is by no means at first sight so clear. The Allegheny drains a very extensive, and not very thickly inhabited, water-shed and much of the population is at a considerable dis- tance from the intake. Nevertheless, the water thus derived is still a river water, wholly unpurified, except for such sedimentation and other im- provement as occurs in the distributing reservoirs; and a close examination of the character and sanitary condition of the water, and the water-shed, of the Allegheny River, ^specially in the light of modern sanitary science' is not reassuring. THE PUBLIC AV ATER SUPPLY. 17 It was for a long time believed, even by engineers and sanitarians that "running water purifies itself." The facts upon which this thesis rested were the obvious disappearance of gross pollution, introduced at a given point in a stream, at points below, and chemical evidence that water drawn at such lower points was less polluted than at the place of contamina- tion. Trusting in this principle, and following the advice of the best engineers of the time, numerous cities and towns, Pittsburgh among the number, introduced systems of water supply derived directly, and without any attempt at purification, from rivers and other streams into which, at points above, more or less of sewage and other polluting materials were freely admitted. Very early, however, it began to be discovered that the purification, which was so obvious on inspection and was further demon- strable by chemical analysis, was, from the sanitary point of view, incom- plete and insufficient. As long ago as 1874 the Rivers Pollution Com- missioners of the British Government, after careful investigation, conclud- ed that, "there is no river in the United Kingdom long enough to secure the oxidation and destruction of any sewage which may be discharged into it, even at its source." From that day until the present it has gradually become more and more clear that such purification as takes place is largely, if not almost wholly, a purification by dilution, and that many of the dan- gerous elements, especially micro-organisms, once admitted, are not in fact removed, but only scattered in a running stream or river. At the same time, it has also gradually become plain that sedimentation and the destruc- tion of micro-organisms by various agencies are more completely effected in standing, than in moving water; so that modern sanitary science has reversed the tenet of thirty years ago and now unhesitatingly affirms that it is quiet water rather than running water that "purifies itself." As a corollary of this modern doctrine, which is supported by an over- whelming mass of evidence, it follows as a matter of course that those cities and towns which, trusting in the earlier teaching, unwisely introduced systems of supply yielding water drawn, unpurified, directly from swiftly running streams, are now finding themselves in an unfortunate predica- ment; for in many of them it has been discovered that typhoid fever and kindred diseases are alarmingly abundant and the conclusion is natural- inevitable even-that in all probability the excess of typhoid fever from which many of them suffer is due to their use of unpurified, sewage- polluted, river water. In some cases, to be sure, it appears that cities and towns so situated do not suffer excessively from this disease, but when this is the case it will generally be found to be true that certain local conditions, readily discoverable, explain their apparent immunity. We may now proceed to a detailed consideration of the character of the Allegheny River and the water-shed from which it is derived in order to discover, if possible, whether or not the conditions which prevail in this 18 THE SOURCES OF TYPHOID FEVER IN PITTSBURGH. case are such as to favor immunity from, or the prevalence of, typhoid fever among those to whom the water is distributed. Before doing this, however, it will be well to enumerate those conditions which, in general, favor and those which hinder the self-purification of streams. The princi- pal condition favoring self-purification is, as has been stated above, quiescence; and closely connected with this condition is the element of time, because quiescence is merely a relative term. It is conceivable that water might be kept quiet for only, a few minutes with very little advantage,-for a few minutes or even a considerable portion of an hour, without any appreciable purification by sedimentation, or by the germicidal action of light, or by other influences tending toward sanitary improvement The time element is also important because there is reason to believe that the germs of typhoid fever do not ordinarily multiply in natural waters, at least in northern latitudes, but, instead, gradually die out. Other things equal, therefore, a slow and quiet stream is comparatively well adapted for self-purification. Other factors of consequence in a case of this kind are the population upon the water-shed,-whether abundant or scanty,- its character, whether gathered in towns and villages or sparsely distrib- uted over a great area in the form of rural population; and, in general, as has frequently been claimed, the proximity or remoteness of such popu- lation. We may now examine one by one these items which together go to make up the character of a river water, and inquire more precisely as to the conditions which prevail upon the stream in question, viz., the Alle- gheny River. the Allegheny river is a rapid stream with little or no OPPORTUNITY FOR SELF-PURIFICATION. Any one who will take the trouble to follow the Allegheny River from Oil City to Pittsburgh, merely as a passenger on the Allegheny Valley Railway, particularly if he is familiar with the streams in the less mountain- ous parts of the country, cannot fail to be impressed immediately with the fact that we have in the Allegheny River a peculiar and characteristic stream. Owing no doubt to the character of the rock through which it has cut its way, it exhibits a very regular decline from Oil City to Pittsburgh. There is no mill-dam of any consequence between these two cities and the river is therefore not, as is frequently the case with rivers in New England and elsewhere a series of mill-ponds, containing slowly-moving water, and in which the elements of sluggishness and quiescence are, except in periods of freshet, the chief characteristics; but rather, even at low water, like a brawling brook making its way rapidly over a stony bed in which are very few pools or other quiet places adapted to purification; in which there is little or no evidence of effective sedimentation,-as is proved by the absence of mud-banks, sand-bars, and the like,-but exhibiting everywhere THE ALLEGHENY RIVER. 19 stones polished by the swiftly-flowing stream, and without effective lodg- ing places for mud or bacteria. An estimate, roughly made, of the rate of flow shows to the traveler a probable velocity in most places of at least a foot per second, and often much more than this, even at low water. With high water the velocity must obviously be much more rapid. Clearly, the two fundamental elements looking towards self-purification in rivers are here wanting, namely, time and cpiiescence. The velocity of the river and the character of its bed are such that foul water introduced, for example, at Oil City, or nearer points, may, and indeed must, arrive at Pittsburgh within a very few hours. Fortunately, however, we do not have to rely on the rough observations of passing travelers but are in posses- sion of authoritative calculation. According to results obtained from the United States Engineer's Office in Pittsburgh, the average velocity of the Allegheny River, even during low water, is from one to two* miles per hour. During high water it is from seven to eight miles per hour and on the average about three and one-half miles. This means that infectious materials poured in at Oil City or nearer points may arrive at Brilliant within fifteen hours and even at low water must arrive within a few days. It has just been shown that in the bed of the Allegheny River very little or no opportunity occurs for purification en route by the usual pro- cesses which are more or less effective in rivers, so that the only question that now remains is, may it not be true that the typhoid germs, if present, die out in the relatively unfavorable environment which the river water supplies? In answer to this question it need only be said that the life of the typhoid germ in water, while it has been variously determined, is without question capable of extending over a considerably greater period than that required for the water of the Allegheny to pass even from remote points on the water-shed to the intake of the Pittsburgh Water Works at Brilliant, so that there seems to be no escape from the conclusion that typhoid fever infection introduced, even at remote points, may and often must be de- livered to the citizens of Pittsburgh in an active and virulent condition. Oil City is distant from Pittsburgh (according to the United States Engin- eers) 113 miles. But such is the peculiar character of the river and such the character of the water-shed, that infection introduced at much more remote points than Oil City may, in my opinion, be actively dangerous to the health of Pittsburgh. I have never seen a river so well adapted in every respect to the swift conveyance of microscopical impurities from great distances. As to the water-shed, it is hardly necessary to do more than to point out that the Allegheny valley in which the river and the railroad run is essentially a cutting or canon, having steep sides and constituting what may be called a "quick-spilling" water-shed; in other words, given a 20 THE SOURCES OF TYPHOID FEVER IN PITTSBURGH. heavy shower or sudden fall of rain, the latter finds its way down the sides of the valley, almost immediately, into the river, naturally carrying with it as a vehicle whatever portable material it encounters. It follows as a matter of course that whatever infectious materials may be deposited on the surface of this valley may readily find their way into the river, and from what has been said above, be quickly delivered to the pumping station at Brilliant. In effect, therefore, although the^greater part of the population on the water-shed of the Allegheny is quite remote and at most not very large, the element of distance appears to be neutralized in this case by the peculiar character of the stream, and the result is the same as if a consider- able polluting population were located just above the intake at Brilliant. It is difficult to exaggerate the importance of this peculiar condition of things; for it means that even a small contamination, though at a great distance, may bear fruit almost immediately in an increased mortality of the citizens of Pittsburgh. It is well known that a relatively small infection of a water supply with typhoid fever germs may under special circumstances be highly effective. The great epidemic at Lowell and Lawrence, Mass., in 1890-91, was traced to a relatively small infection of a relatively insignificant feeder of the Merrimac River, from which the water supply of these cities was derived. In that case the germs of the disease passing out of the little feeder appeared to have mingled with the relatively large mass of water of the Merrimac River and to have found their way to the intake pipe, on the opposite side of the river, some three miles below. The ele- ment of proximity was there undoubtedly important because the Merri- mac River is in effect a series of mill-ponds, the particular pond which was infected being some sixteen miles in length and affording at low water, abundant opportunity for sedimentation and other factors of self-purification. In the case of the Allegheny River, a similarly small infec- tion washed in from the water-shed by a heavy shower, or finding its way in at any point on the main river or its larger tributaries, in the ab- sence of any similar mill-pond features, and in the presence of a swiftly flowing stream, must be carried rapidly to the intake at Brilliant in a relatively fresh and virulent condition. . We have then obviously, in the case of the Allegheny River, a vehicle highly favorable for the conveyance of typhoid fever germs from almost any point upon the water-shed, however remote; and this is particularly the case whenever a heavy rainfall occurs, causing the river to rise and making it muddy. The mud in the river is familiar and visible evidence of the efficiency of the stream as a carrier of dirt and debris. But there is other and still more valuable evidence, name- ly, that supplied by bacteriology. The experienced Bacteriologist of THE ALLEGHENY RIVER. 21 your Commission, Mr. Copeland, has from the beginning of the inves- tigations kept close watch of the bacterial characteristics of the water of the Allegheny, not-only as it arrives at the pumping station at Brilliant, but also during its brief stay in the reservoirs, and as it is drawn from the service pipes by the citizens; and his results show conclusively, not only that the Allegheny is a highly effective vehicle of bacteria,-which abound in its too-often turbid waters,-but also that particular kinds of bacteria are generally present which point unmistakably towards ex- tensive sewage pollution. Among the myriads of ordinary bacteria of earth, air, water, and animal intestines, present in sewage, those of ty- phoid fever are so few that all search for them by competent observers is usually in vain. If it were not so, if the typhoid germs were so abun- dant is to be readily detected or even detected at all, any city using such water for drinking purposes must surely be depopulated; for even in sewage, in comparison with the whole number of common bacteria, those of typhoid fever are probably as rare as planets are among the stars, while, unlike the planets, they have no well marked features of size or motion which enable them to be readily distinguished from their neighbors, but rather so closely resemble many of them as to be distinguishable, even when found, only by long and patient study. The germs of typhoid fever bear, on the contrary to the harmless germs of sewage some such relation as do murderers to ordinary citizens, in the passing crowd upon a busy street. They are very few in number and outwardly resemble very closely the law-abiding. Even expert de- tectives on the watch may not be able to discover them. It is only after- wards that often unseen and unsuspected, they do their deadly work. Even then they may escape detection in the crowd, and it is only when circum- stantial evidence is overwhelming, or when they are taken in the very act, red-handed, that their true character becomes manifest. The germs of typhoid fever in sewage-polluted water can rarely, if ever, be detected among the hosts of harmless organisms present and which they closely resemble. But if the use of such sewage-polluted, unpurified water is followed constantly by numerous cases of typhoid fev- er, there is, in the absence of other obvious causes, overwhelming cir- cumstantial evidence of their presence. When, in addition, we remember that in this case typhoid fever is not uncommon on the water-shed; and that the latter is of such a character as to favor the speedy delivery of surface water to the citizens of Pittsburgh well inside the time during which the typhoid germ is known to retain its vitality and virulence in water; the case, in the absence of any other reasonable explanation, and of any shadow of evidence, even in opposition, becomes so strong as to amount to a demonstration. 22 THE SOURCES OF TYPHOID FEVER IN PITTSBURGH. DISTRIBUTION OR TYPHOID FEVER IN PITTSBURGH. The engineers of your Honorable Commission have prepared a map,1 a copy of which I am kindly permitted by them to include in my Report, showing the typhoid mortality per 10,000 inhabitants in the various wards of the city. It should be stated at the outset that the population in each ward is somewhat uncertain inasmuch as no census by wards has been taken since the United States Census in 1890 (the Police Census in 1897 being by Police Districts), and it will not do, therefore, to depend absolutely upon the results given upon the map. Nevertheless these are very instructive. It will be observed that no inhabited portion of the city is entirely free from the disease. Some wards appear to have suffered more severely than others, as would be expected when we recall the fact that typhoid fever arises from various sources for, as we have already pointed out, whatever the principal cause in Pittsburgh may be, numerous contribu- tory causes unquestionably exist. Another and perhaps more valuable aid in answering the ques- tion at stake, whether the distribution in general and broadly speaking, is conformable to the density of the population, is, perhaps, to be deriv- ed by observing the actual location of the cases of typhoid fever reported in Pittsburgh during the twelve months of 1897. A map2 showing the location of these cases, and prepared under my direction by the Engineers of your Commission, is also appended as a portion of this Report. It will be observed that no part of the city which is at all thickly populated or likely to have used the city water, was free from the disease and that, broadly speaking, the cases appear to be distributed as nearly as might be expected in a case like this, according to the density of the population. So far then as these methods of examination go, the one extending over six years and the other over one year, they tend to show precisely such distribution of the disease as might be expected from one principal and widespread source affecting all parts of the city. I must repeat that exact conformability to density of population cannot be expected owing to the varying influences of the several contributory factors which go to make up the total typhoid fever of any modern city; but in my opinion it is not unfair to conclude, from the facts of the distribution of typhoid fever and of a polluted water supply, especially in the absence of any other sat- isfactory cause and under the peculiar conditions represented by the Allegheny River, that there is a close and significant connection between the two. 1 See Plate No. i, opposite Page 22. 2 See Plate No. 2, opposite Page 24. P late No. I CITY OF PITTSBURGH FILTRATION COMMISSION MAP OF PITTSBURGH SHOWING REPORTED NUMBER OE CASES OF TYPHOID FEVER IN EACH WARD 1892-1897 Nobe : The estimated populations tor 1897 are ^iven under the Ward Numbers. The reported number of cases of Typhoid Fever for each year are $iven for each Ward for every Ten Thousand of estimated population. SCALE OF FEET JANUARY 1899 SUMMARY AND CONCLUSION. 23 THE ALLEGHENY RIVER NOT THE ONLY POLLUTED WATER SUPPLY OF PITTSBURGH. It has already been pointed out that the Monongahela River is a most objectionable source of water supply for the South Side. The citizens of Pittsburgh itself are to some extent exposed to another and grave danger in the use, to a certain extent, of water taken directly from the Allegheny River by mills and manufactories and so disposed within these establish- ments as to be accessible to, and, in fact, to a considerable extent used for drinking by laborers and others therein engaged. Several of the manti • facturing establishments located on the Allegheny River pump water taken directly from the river opposite their works and distribute it throughout the establishments for various purposes but in such a way that it is accessible for drinking. It is hardly necessary to say that these supplies must be highly objectionable, inasmuch as they are derived from a river not only extensively sewage-polluted above Brilliant, but also se- riously polluted below Brilliant, yet above the establishments in question, by sewers of the city itself. It is a well-known fact that consumers often will not stop to inquire whether a water is safe or not provided it is readily accessible and agree- able in taste or temperature; and I have no doubt that a considerable amount of typhoid fever in Pittsburgh in the past has arisen from this source. Even should the supply taken at Brilliant be purified by filtration I should expect to see some typhoid fever still prevailing in the city in part traceable to these mill supplies. It seems to me imperative that whatever else is or is not done these supplies taken directly Rom the river should be abandoned immediately, or else so arranged in the mills or other estab - lishments in which they exist as to be inaccessible for drinking purposes. I have already indicated above the fact that the use of Monongahela River water on the South Side may have caused some disease on the north- side, and the same line of reasoning would cause me to expect to find in Pittsburgh a considerable number of cases derived from the use of polluted waters in Allegheny, or other neighboring cities and towns. It is pos- sible, also, that a few cases in Pittsburgh may be due to the use of infected spring waters which, even under high sounding names, are by no means always above suspicion. SUMMARY AND CONCLUSION. We may recapitulate as follows:-It is probable that a portion of the typhoid fever in Pittsburgh is derived from polluted milk, from secondary infection, from atmospheric dust, and from outside sources; but the con- stancy and general distribution- of the disease point, in the strongest man- ner, to some other cause than these, which may indeed be regarded as contributory factors but cannot be regarded as its principal source. On 24 THE SOURCES OF TYPHOID FEVER IN PITTSBURGH. the other hand, the same facts which disqualify these as the principal causes strongly suggest some widespread, general, and constant source, such as the water supply would be; and on examining the character of the water supplied to Pittsburgh, it appears that it is derived from rapid and turbid rivers into which abundant sewage finds its way and by which such sewage is very speedily delivered, unpurified, to the consumers. In other words, the water supply fulfills precisely the conditions required to explain the facts. I am therefore forced to conclude that this is in all probability the principal source of the constant and excessive amount of typhoid fever in Pittsburgh. Respectfully submitted, William T. Sedgwick. November io, 1898. Plate No. 2 CITY or PITTSBURGH FILTRATION COMMISSION MAP OF PITTSBURGH SHOWING LOCATION OF REPORTED CASES TYPHOID FEVER I N 1897 JANUARY 1899 OF THE Consulting Engineer. ALLEN HAZEN, C. E. EXHIBIT 2. Mr. Robert Pitcairn, Chairman, Filtration Commission ; Pittsburgh, Pennsylvania. Sir :- I beg to submit the following report in regard to the water supply of Pittsburgh, and the means to be taken for its improvement. The city of Pittsburgh, with a present estimated population of 320,- 000, is situated at the junction of the Allegheny and Monongahela Rivers. The city water works draw water from the Allegheny River at Brilliant, and supply a part of the city having a population of approximately 234,- 000, and most of this population is supplied from the city works. Another part of the city is supplied with water from the Monongahela Water Company, drawing water from the Monongahela River. The district supplied in this way has an estimated population of 78,000. The re- maining portions of the city, with an estimated population of 8,000, are supplied by two other private companies. The water as now supplied by the city works from the Alle- gheny River is at times very muddy. The river is also' polluted by a considerable quantity of sewage, and there is reason to suppose that it is, or that it may become, injurious to health. We have to consider, therefore, first, whether or not the water as now supplied by the city works is unhealthy, or is likely to become unhealthy, and second, to determine the feasibility and cost of removing, by means of filtration or otherwise, the objectionable qualities, whether unhealthy or not; and third, to determine whether any other source of supply can be sub- stituted to advantage for that now in use. The question of the health fulness of the Allegheny River water is found to present some very interesting problems. The amount of sewage entering the river is very much less, relatively, than the volumes of sewage entering other American rivers used for public water supplies; but notwithstanding this, the city has had an exceptionally high death rate from typhoid fever for many years. In view of the unusual diffi- culties of the question, the matter was referred to Prof. William T. Sedgwick, of the Massachusetts Institute of Technology, who has made a report thereon, which has been presented to you, and which deals with the matter quite fully. In taking up the question of the feasibility and cost of purifying the Allegheny River water, a number of important questions presented themselves. Sand filters, operated at rates of from two to five million gallons per acre daily, have been used in many European cities and a 28 REPORT OF THE CONSULTING ENGINEER. smaller number of American cities for many years, and have been con- spicuously successful in removing those bacteria from surface waters whose presence would otherwise cause disease. Most of the waters so purified, however, have been drawn from lakes or reservoirs, or from rivers not subject to excessive muddiness; such rivers, for example, as the Merrimac and the Hudson in this country, and the Thames and the Spree in Europe, which do not approach in muddiness the Allegheny River at Pittsburgh. It was known in a general way that special precautions had to be taken in the treatment of muddy waters by this process, but no data were available to determine the extent of the precautions, nor the exact results which could be obtained in the removal of mud. The crude petroleum, mine drainage, etc., which occur more or less regularly in the Allegheny River water, were also factors, the importance of which could not be determined without trial. Another system of filtration, known as mechanical filtration, has been somewhat extensively used in the United States by cities smaller than Pittsburgh. This system of filtration is commonly used at rates of about 100 million gallons per acre daily, and chemicals, usually sulphate of alumina, are employed in connection with it, to assist the separation of the solid matters and to allow clarification to take place at higher rates than would otherwise be possible. This system of filtra- tion has met with considerable success in the clarification of very muddy waters. Owing to the fact that it has principally been used for such waters, and rarely for the purification of waters containing considerable quantities of sewage, but few data were available as to its effectiveness in the removal of any disease producing qualities which might be present. In view of this condition of affairs it was deemed advisable to make experiments upon a considerable scale with these two systems of filtration, to determine whether or not sand filtration was capable of clarifying the Allegheny River water, and whether or not mechanical filtration was capable of removing sufficiently the bacteria as well as the turbidity; and also to determine as far as possible the conditions essential to success with each system; as, for example, the rate of filtration which could be safely employed; the quantity of chemicals which it is necessarv to use; the necessity of preliminary sedimentation, etc. The two above mentioned methods of filtration are the only ones which have achieved conspicuous success, or have been adopted on an important scale. Other methods of filtration have been devised which have been tried experimentally, and in some cases municipal plants have been constructed upon them. In connection with our experiments, REPORT OF THE CONSULTING ENGINEER. 29 therefore, we have made certain investigations, in part by experiments, and in part by examination of plants, experimental or otherwise, upon various other systems of filtration, to determine if there was anything in them which could be used to advantage in treating the water of the Allegheny River. In estimating the cost of filtration, it has been necessary to consider the probable growth of the city and the possible extension of the municipal water supply to those parts of the city not at present supplied by the city works, and to make estimates of the amounts of water required for the proper supply of these populations. In this connection the prevention of waste of water is of vital importance, as it affects the quantity of water which must be provided, and consequently the cost of filters. Estimates of costs of filters upon various systems and in various localities have been made in detail, which, in connection with the results obtained in our experimental trials of the various systems, show to what extent the Allegheny River water can be purified, and the cost of doing it. It has been suggested that a large part of the water supplied by the city water works is used for manufacturing purposes, and that it might be possible, at reduced cost, to install a separate system to supplv river water for such uses, and to provide filters for only that part of the supply required for domestic purposes. This plan, therefore, has been considered in ' comparison with the cost of filtering the whole supply. All projects for the improvement of the present supply involve the construction of filter plants, and their operation, at a considerable expense; and they also involve pumping all of the water from the Alle- gheny River to the city reservoirs, as it is now done, at a heavy annual expense. If a source of supply could be found, high enough to flow by gravity through conduits to the city reservoirs, the cost of pump- ing would be saved; and if the water was derived from a sparsely populated water-shed, which could be controlled by the city, the necessity of filtration would be avoided. We have, therefore, made examinations to see if such a supply could be obtained; and having found such a source, we have made investigations as to the feasibility and cost of supplying the city of Pittsburgh in this manner. In connection with this study the services of Mr. Emil Kuchling, Chief Engineer of the Roch- ester Water Works, have been secured. In connection with the various problems here briefly outlined, very many studies and estimates have been made, which are given more at length under their respective / headings. 30 REPORT OF THE CONSULTING ENGINEER. SANITARY CONDITION OF THE PRESENT WATER SUPPLY DRAWN FROM THE ALLEGHENY RIVER. The Allegheny River at the Brilliant pumping station has a drainage area of about 11,400 square miles. The most important cities and towns upon this drainage area, and their approximate differences from the water works intake, are as follows:- Cities and Towns upon the Allegheny River and Tributaries above Brilliant Pumping Station. Place. Distance in Miles. < Population in 1880. 1890. 1900. (Estimated). Verona - 3 L599 L497 1,364 Oakmont 4 1,678 1,678 New Kensington .... ii 4,627 Tarentum 14 i-245 9,254 b reeport 1,614 1,637 1,660 Ford City • • • • 33 1,156 1,255 1,255 Apollo •• • • 35 2,156 4,003 Kittanning • • • • 38 2,624 3,095 3,650 Saltsburg • • • • 47 855 1,088 1,384 Red Bank • • • • 57 . East Brady 1,242 1,228 1,213 Latrobe .... 64 1,815 3,589 7,097 Blairsville •••• 65 1,162 3,126 6,252 Derry .... 72 755 1,968 3,936 Parker .... 76 L835 i,3i7 945 New Bethlehem • ••• 77 773 1,026 1,362 Indiana .... 78 1,907 1,963 2,049 Emlenton .... 82 1,140 1,126 1,112 Punxsutawney •••■ 85 674 2,792 5'584 Johnstown .... 89 8,380 21,805 43,6io East Conemaugh ... . 92 756 1,158 1,774 Hammerstown .... 94 1,014 1,014 Brookville .... 98 2,136 2,478 2.875 South Fork Clarion .... 99 .... 100 1,169 1,295 2,164 i,295 4,006 Ebensburg Reynoldsville Franklin Du Bois Oil City .... 112 .. .. 112 ... . 116 .... 121 1,123 1,410 ^,010 2,718 1,202 2,789 6,221 6,149 1,287 5,504 7725 12,298 .... 125 7,315 10.932 16,340 P late No. 3. C/TY OF PITTSBURGH. FILTRA TI ON COMMISSION. WATERSHED OF ALLEGHENY RIVER above PITTSBURGH WATER WORKS. Circles show popu/ation in 1880, 1890, and estimated population for J900. Only one circle shows no growth or very slow growth SANITARY CONDITION OF PRESENT WATER SUPPLY. 31 „ Population in Place. Distance in Miles. 1880. 1890. 1900. (Estimated). Stoneboro • , 125 I,l86 i,394 ' 1,638 Ridgeway 14O 1,100 9,046 1,903 3,292 Titusville 142 8,073 7,205 Meadville • • 144 8,860 9,520 10,229 St. Marys . . 148 1,50! B745 2,029 Johnsonburg ... 149 1,280 1,280 Wilcox ... 151 1,037 1,037 Tidioute 160 1,255 1,328 1,405 Edenboro l6l 876 1,107 B399 Waterford I/O Sheffield 1/2 684 1,295 2,452 Union • • U7 2,171 2,216 2,262 Clarendon l8o 295 1,297 2,594 Warren l8l 2,810 4,332 6,678 Corry • • 195 5,277 5,677 6,108 Busti, N. Y . . . 205 1,901 2,089 2,296 Jamestown, N. Y . . . 210 9,357 16,038 27,489 Randolph, N. Y . . . 212 1,111 1,201 3,692 1,298 Salamanca, N. Y . . . 222 2,531 5,386 Mayville, N. Y 227 1,051 1,164 1,289 Bradford ; . . . 24O 9J97 10,514 12,010 Kendall . . . 24O 2,689 i,937 B395 Olean, N. Y ... 24I 3,036 7,358 14,716 Cuba, N. Y . . . 256 1,251 1,386 i,536 Franklin, N Y . . . 258 672 1,021 i,55i Eldred ... 263 1,165 1,050 946 Port Allegheny 266 73i 1,230 2,070 Smethport ... 267 872 1,150 i,5U Coudersport ... 282 667 B53O 3,060 Total urban population. .. 121,705 185,939 277,693 Urban population per square mile, 11 16 24 Of the above towns it is fair to assume that only the larger ones are yet sewered, and that the population contributing sewage to the river is only a fraction of the total as given. The populations are increasing rapidly, however, and the use of sewers even more rapidly, so that the amount of polluting matter entering the river, already con- siderable, is sure to increase rapidly. As compared with other rivers used for municipal supplies in this country and in Europe, the urban population is comparatively small, and REPORT OF THE CONSULTING ENGINEER. 32 most of it is far removed from the present intake. The effect of this population upon the healthfulness of the source of supply is discussed at length by Professor Sedgwick, in his report upon this subject. SANITARY CONDITION OF THE WATER SUPPLIED TO THE SOUTH SIDE FROM THE MONONGAHELA RIVER. As a considerable part of the city of Pittsburgh is supplied from the Monongahela River, investigations have been made of the quality of the water supplied. The drainage area above the intake of the Monon- gahela Water Company is about 7,600 square miles. The most im- portant cities and towns upon this drainage-area are as follows :- Cities and Towns upon the Monongahela River and Tributaries above Intake of Monongahela Water Company. , Population in Place. Distance 1880. 1890. 1900. in Miles. (Estimated). Lower St. Clair 3 4-303 4-303 Homestead 6 592 7-911 15,822 Braddock 9 3>3io 8,561 17,122 W ilkinsburg 9 L529 4,662 9-324 Port Perry ii ^-17100 1-031 966 Turtle Creek 12 Wilmerding 13 419 419 McKeesport 14 8,212 20,741 41,482 Elizabeth 20 I,8lO 1,804 1-798 Irwin 23 1-444 2,428 4,070 Jeannette 29 3-296 3-296 Monongahela City 29 2,904 4-096 5-777 West Newton 32 1-475 2,285 3-539 Greensburg 33 2,500 4,202 7-063 Belle Vernon 4i 1,164 IJ47 1,130 Everson 50 Scottdale 52 1-275 2,693 5-688 Brownsville 52 1,489 1,417 1-352 Bridgeport 55 1,134 I-O3O 927 Mt. Pleasant 57 1,197 3>652 7-304 New Haven 57 442 1,221 5-629 1,381 2,442 Connellsville Dunbar 57 61 3-609 8,780 1-381 Uniontown 69 3-265 6-359 12,380 Waynesburg 80 1,208 2,101 3-654 P late No. 4. CITY OF PITTSBURGH Fl LT RA T/ON COMMISSION WATERSHED OF MONONGAHELA RIVER Alien Hazen Consult mg Engineer. Dec. /698. Circ/es show popuiation in /88Ot /890an a! estimatedpopu/ation for 1900. Only one circ/e shows no growth or very s/ow growth. SANITARY CONDITION OF WATER SUPPLIED TO SOUTH SIDE. 33 Place. Distance in Miles. , Population in 1880. 1890. 1900. (Estimated). Fairchance ■ 95 1,092 1,092 Morgantown, W. Va • • 95 745 1,on 1,372 Somerset 112 1,179 i,7i3 2,489 Meyersdale 112 1423 1,847 2,397 Fairmount, W. Va 120 900 1,023 1,163 Grafton, W. Va 140 3.030 3,U9 3494 Clarksburg, W. Va • • 150 2,307 3,oo8 3,922 Weston, W. Va l80 1,516 2,143 3,030 Buckhannon, W. Va l8o 761 1,403 2,587 Total urban population. .. 5B52O 108,768 181,365 Urban population per square mile, 7 14 24 The urban population per square mile upon the Monongahela River is equal to that upon the Allegheny. There is this important difference, however, that while most of the urban population upon the Allegheny is at points far away from the water intake, that upon the Monongahela is largely concentrated within a comparatively short dis- tance from the intake. The Monongahela River also receives a much larger amount of mine drainage than the Allegheny, and this mine drain- age affects and greatly increases the mineral matter contained in it. During the year ending July 31, 1898, the average compositions of the two rivers were as follows :- Monongahela. Allegheny. Turbidity .... (Results incomplete) 0.17 Color " 0.20 O.29 Alkalinity i-35 2.87 Solids 20.08 15-6 Suspended Matter 6.3 3-9 Hardness 4-40 3-55 Chlorine 1.18 2.17 Sulphuric Acid 4.00 1.48 Iron .... 0.0966 0.0543 Free Ammonia 0.0066 0.0019 Albuminoid Ammonia 0.0149 0.0117 Nitrates 0.0880 0.0705 Nitrites 0.0000 0.0000 Bacteria 22,833 I7,3i4 These results are taken for the calendar year. Our examinations have extended over a somewhat longer period, but averaging the whole time would include two summer or low water periods, and only one REPORT OF THE CONSULTING ENGINEER. 34 spring or high water period, and would obviously not give representative results. It will be seen from this comparison that the water of the Monon- gahela carries more suspended matter, is harder, and contains more organic matter and more bacteria, than the water of the Allegheny. Its alkalinity is very much less, owing to the presence of a larger amount of acid mine drainage. The Monongahela River is said to become acid at times, although it has not done so during the period covered by our analyses. From every standpoint the water of the Allegheny is more desir- able for a municipal water supply than that of the Monongahela, and we have considered it probable that the present supply for the South Side, now drawn from the Monongahela, would ultimately be abandoned, and that the Allegheny River supply would be extended to this portion of the city. muddiness. The water of the Allegheny River is always more or less turbid; occa- sionally it becomes very muddy. The water is pumped from the river to distributing reservoirs, where a part of the suspended matter is remov- ed by sedimentation. Even with this sediment removed, the water as sup- plied is very often so muddy as to be seripusly objectionable to those who use it. A record has been kept since the commencement of our work of the muddiness of the river water. To measure the turbidity or muddiness of water a platinum wire is fastened to a long stick and is sunk into the water as far as the wire can be seen. At the point where the wire is just ready to disappear from view its depth below the surface is measured, and the depth forms a measure of the muddiness of the water. For con- venience the muddiness is recorded as the reciprocal of the depth at which the wire can be seen in inches. During continued dry weather with very low water the turbidity falls to 0.03, with the wire visible 33 inches below the surface. After summer rains the turbidity is increased water stages a turbidity of 0.10 is common, with the wire visible ten inches below the surface. After summer rains the turbidity is increased to 0.20 to 0.50, with the wire visible from five to two inches. Heavy rains result in turbidities of 1.00, with the wire visible one inch below the surface, and this may be considered as the ordinary maximum turbidity of the river. On three occasions has this turbidity been exceeded; namely, March 23, when with the highest freshet this year, the turbidity rose to 2.38, with the wire visible less than half an inch from the surface; on May 17, when the turbidity rose to 1.20; and on August 20, when a turbidity of 1.75 was observed. The following is a tabular statement P late No. 5. The heavy fine represents the temperatures dur/ng the experiments. CITY OF PITTSBURGH FILTRATION COMMISSION AVERAGE MONTHLY TEMPERATURES AT PITTSBURGH JAN.I887TO SEPT.I89S. MUDDINESS. 35 of the number of days on which the various turbidities were observed in the water of the Allegheny River at the Brilliant pumping station, for the year ending July 31, 1898 :- Turbidities. N umber of Days. Percentage of Total Number of Days. Above i.oo 2 o-5 0.51 to I.oo 21 5-8 0.21 to 0.50 51 14.0 O.II to 0.20 64 17-5 0.06 to 0.10 94 25-7 0.02 tO O.O5 133 36.5 365 100.0 Average turbidity, 0.17. It was at first thought that the turbidities bore a relation to the height of the river, and that this relation could be established from the records of this year and applied to the records of river heights for pre- vious years, and in this way an approximate computation of turbidities extending over a longer period could be made. It was found, however, upon comparing the turbidities and river heights that no definite rela- tion could be established. Occasionally a sharp but not high rise of the river is followed by a very high turbidity, while on the other hand, a very much higher rise under other conditions is accompanied by less muddy water. As the condition of the river depends more or less directly upon the meteorological conditions, the records of monthly precipitations and tem- peratures have been secured for the past ten years and plotted. These plottings are presented herewith.* The conditions during the period cov- ered by our experiments are shown by heavy lines and the corresponding conditions for other years dotted lines. It will be seen that March, 1898, was exceptionally warm, and April exceptionally cold. Both July and August were warmer than the average, although not reaching the highest record for monthly heat. October, 1897, was also a warm month. The winter was not exceptionally severe, although February was colder than the average. The precipitation was exceptionally heavy in November, 1897, and March, 1898, and exceptionally low in September and October, 1897. On the whole, both precipitation and temperature records are essentially normal, and present about the same range as has been common during the last ten years. It is perhaps a fair deduction that our record of turbidities extending over more than a year affords a good idea of the general condition of the river for a period of years, and we have no reason * See Plate No. 5, opposite Page 34, and Plate No. 6, opposite Page 36. 36 REPORT OF THE CONSULTING ENGINEER. to believe that the condition of the river during this period has been other than essentially normal. The presence of this mud in the water is a source of serious inconven- ience and discomfort to the people using it, and is objectionable in man) mechanical operations for which the water is used. To remove this mud is one of the most important objects to be reached by filtration, and has been carefully considered in all our investigations. NATURE OF FILTRATION. The filtration of water consists in passing it through some substance which retains and removes the suspended matters contained therein. Under certain conditions matters in solution are also removed. In sand filtration as practiced in Europe for many years, and in this country on a less extensive scale, the water is passed through sand contained in large masonry basins, at a rate not exceeding, in general, five vertical inches per hour, or three million gallons per acre daily, although somewhat higher rates are occasionally used. The filtered water is removed from below through underdrains surrounded by gravel. Filters are construct- ed in sections so that parts can be put out of service and cleaned while other sections are furnishing the supply. JThis method of filtration is used for filtering the water supplied to cities with an aggregate population of over twenty millions of people. In mechanical filtration the rate at which water is passed through the sand is increased many times, commonly to 150 to 200 vertical inches per hour. The efficiency of filtration is, in general, inversely propor- tional to the rate, and purification of water at such rates would be impos- sible were it not for the introduction of other factors. The element re- lied upon in mechanical filtration to allow satisfactory results to be ob- tained at high rates is alum, or sulphate of alumina. This chemical is added to the water to be filtered and is decomposed into its component parts,-alumina and sulphuric acid. The sulphuric acid remains in the water, while the alumina forms a gelatinous precipitate which surrounds and entangles the fine suspended particles in the water and allows them to be removed much more readily than would otherwise be the case. Objection has been raised to the use of alum on hygienic grounds, but when due care is exercised in its use, it is doubtful if it is ever really in- jurious to health. Water usually contains sufficient lime to combine with the sulphuric acid, forming the comparatively harmless sulphate of lime, while nearly all of the alumina is removed in the process of filtration, and it is not clear that it is injurious to health, even if an extremely small quantity is found in the effluent. P late No. 6. CITY OF PITTSBURGH FILTRATION COMMISSION MONTHLY PRECIPITATIONS AT PITTSBURGH JAN. 1888 TO SEPT.I898. The heavy line shows the precipitations during the experiments. EXPERIMENTS UPON FILTRATION. 37 EXPERIMENTS UPON FILTRATION. There have been installed and operated at the Brilliant pumping station one sedimentation basin, two sand filters, one Jewell mechanical filter, one Warren mechanical filter, and also a set of artificial sandstone tiles on the Fischer system. It was not the object of these experiments to settle all questions in regard to filtration which might be raised, but rather to determine the power of sand filters to deal with water as mud- dy as that of the Allegheny, and to ascertain what bacterial efficiencies could be secured by mechanical filtration, and to afford information on some purely local problems. These experiments also served as practical demonstrations of the results obtained by the different processes, and afford a basis for direct comparisons between them, each operated under as favorable conditions as could be secured. With the sand filters it was assumed that the kind of sand to be em- ployed, the depth of sand, the limit to the loss of head, the rate of filtra- tion, and the general arrangement and operation of the plant were suffi- ciently well known from experiments made elsewhere and from general practice; and the filters were constructed to represent what might be considered the best practice in these respects, and no attempt has been made to investigate them. It was intended, however, to secure data upon the following points :- i. Whether the Allegheny River water could be successfully filtered without preliminary sedimentation, and whether such sedimentation was desirable. 2. Whether it would be necessary or desirable to cover filters for use in the climate of Pittsburgh. 3. To deterffiine whether or not the mud, crude petroleum, mine drainage, and other substances present in the Allegheny River water would interfere with the work of filtration, and cause results to be ob- tained materially different from those which have been obtained else- where. 4. To determine the frequency with which it would be necessary to clean filters, both with and without preliminary sedimentation, this information being necessary to a computation of the cost of operation. With regard to mechanical filters, it was assumed that the filters used represented the most perfect types of mechanical filters yet con- structed, and that the results obtained with them could be regarded as representing the best obtainable results under these processes. The questions presented in connection with them were whether or not efflu- ents could be obtained equal in bacterial purity to those obtained from sand filters, or if not equal, at least of satisfactory quality; and second, to determine what quantity of coagulant would be required to accomplish satisfactory results at various river stages. 38 REPORT OF CONSULTING ENGINEER. results from experimental filters. The work of installing and operating experimental filters was placed in charge of Mr. Morris Knowles, Resident Engineer of the Commission, who has made a report, giving in detail descriptions of the work thus done, which report is hereto appended. The biological examinations were made by Mr. William R. Copeland, Bacteriologist of the Commis- sion, who was provided with a temporary laboratory near the filters, and who also gave his personal attention to many matters connected with their operation. Chemical analyses were made by Dr. Walther Riddle, Chem- ist of the Commission. Both Mr. Copeland and Dr. Riddle have made reports upon the methods employed by them, which reports are hereto appended. Full tabular statements of the daily results from each of the filters are given in Mr. Knowles' report. For convenience a summary of the monthly results is here presented. RESULTS FROM EXPERIMENTAL FILTERS. 39 Summary of Results from Sand Filters by Months. Turbid- BACTERIA PER CUBIC CENTIMETER. * BACTERIAL EFFICIENCY, JET YIELD OF FILTERS IN MILLION GAL- Month, ity of Raw Raw Settled Effluents. PER CENT. LONS PER ACRE DAILY. Water. Water. Water, no. 1. No. 2 . No. 1. No. 2. No. 1. No. 2. 1897- August. ... . O.I9 2,089 1,283 46 42 97.80 97.99 2.40 2.3O September. • O.O5 2,478 1,231 l6 l6 99-35 99-35 2.98 3.00 October. .. . O.O4 72,878 39,186 32 32 99-96 99.96 2.90 2.95 November. . 0.24 25,220 29,924 346 632 98.63 97.49 2.64 2.42 December. . O.I9 14433 I4,923 163 225 98.87 98.44 2.76 2.46 1898. January... . 0.27 15,333 13,828 334 310 97-82 97.98 2.77 I.87 February. . O.I5 9,430 12,043 266 275 97.18 97.08 2-93 2.27 March.... • O.3O 11,747 12,347 71 332 99-40 97.17 2-95 2.83 April , 0.08 5,010 4,298 33 91 99.34 98.18 2-95 2-99 May O.I9 10,800 6,770 no 99 98.98 99.08 2-93 2.95 June . O.I9 11,100 5,930 135 72 98-78 99-35 2.83 2.85 July , O.II 16,800 13,000 74 89 99-56 99.47 2-94 4-97 August. .. . O.36 15,100 10,250 51 82 99.66 99.46 2.85 4.82 - ■ ■ ■ ■ Averages.. . 0.18 16,340 12,693 I29 177 99.21 98.92 2.83 2.98 Note :-No. 2 was operated with raw or unsettled water from July 24 to December 19, and from February 20 to June 30, otherwise settled water was applied to both filters. Composition of Allegheny River Water Before and After Settling and After Passing Through Sand Filters, for the Thirteen Months, Ending August, 1898. River Sample. Gate Chamber Sample. After Passing Settling Basin. Effluents. No. 1. No. 2. Color . . 0.29 0.29 0.27 0.09 O.O9 Alkalinity . . 2.89 3-05 3'07 4-i3 4.22 Total Solids . .15.9 15-5 i3-i 12.1 12.1 Suspended Matter . . 4.2 3-9 i-3 0.0 0.0 Hardness •• 3-58 3-67 3-69 4.72 4-83 Chlorine . . 2.19 i-99 2.08 2.06 2.02 Sulphuric Acid . . I.44 i-47 1.38 i-44 i-44 Iron . . O.O516 0.0724 0.0605 0.0160 0.0179 Nitrogen as,- Free Ammonia . . O.OOI9 0.0019 0.0019 0.0016 0.0016 Albuminoid Ammonia . . . O.OIl6 0.0115 0.0108 0.0063 0.0064 Nitrates . . O.O684 0.0665 0.0641 0.0715 0.0647 Nitrites . . 0.0000 0.0000 0.0000 0.0000 0.0000 Bacteria .. 17,405 16,314 12,663 129 176 REPORT OF CONSULTING ENGINEER. 40 Summary of Results from Mechanical Filters by Months. GENERAL SUMMARY,-WARREN FILTER. Month,-1898. Turbidity of Raw Water. BACTERIA PER CUBIC CENTIMETER. Bacterial Efficiency, Per Cent. c 0 0 •'"rt 22° E « ag co 5 0 Wash and Waste, Per Cent. Rate of Filtration, Million Gallons Per Acre Daily; When in Service. River Water. Effluent. February . .. O.I5 9,430 238 9748 0.70 5-3 104 March O.3O 11,747 164 98.6O 1,81 4-8 I08 April 0.08 5,010 78 9844 0.86 3-7 122 May 0.19 10,800 630 94-20 i-55 34 115 June .... ;. O.I9 11,100 115 16,800 320 98.96 1.36 5-i 103 July O.II 98.IO 1.46 6-5 119 August .... 0.36 15,100 290 98.O8 1.76 6.4 137 Averages . .. 0.20 11,427 262 9770 1.36 5-o 115 Note :-Special experiments were made during May. Excluding May, average bac terial results were; raw water, 11,531; effluent, 201; bacterial efficiency, 98.26 per cent. GENERAL SUMMARY,-JEWELL FILTER. February . .. 0.15 9430 638 93-23 0.56 6.1 98 March 0.30 11,747 208 , 98.23 1.07 4-3 IO6 April 0.08 5>o!o T59 96.83 0-54 2.8 I06 May 0.19 10,800 150 98.61 I.OI 4.6 I06 June 0.19 11,100 1,450 16,800 345 86.9O 1.18 54 I06 July O.II 97-95 I-3I 7.6 103 August .... 0.36 15,100 260 98.28 i-35 6-3 103 Averages . .. 0.20 11427 459 • 95-99 1.00 5-3 IO4 Note :-Special experiments were made during June. Excluding June, average bac- terial results were; raw water, n 481; effluent, 293; bacterial efficiency, 97-45 Per cent. RESULTS FROM^EXPERIMENTAL FILTERS. 41 > 2 p 70 CD in Totals .... > § § p •« p g. g G JU O - • 4* p • ' • ' g J > < 2 b 7Q G m H o p, ST "3^ s " £3 ?g EZ • . . S' b p g o D ~| • • l-» ***x 1 00 00 oiTJ- • <b xj b1 POJ1 b1 P^ 0X00 to bo 00 J (_n CO Co -k Cn xj co KO Ox J P°P°\P 'p OCX! w CO 'to to bi OXCn Ji 00 O CM OX o Cn 00 o KO Entering Water. to 004^ Ox oocn \o KO > KO OXKO Cn KO 00CO CO Ox M KO 4^ W KO XJ o !-* O CO Waste Before rZ Ox 4^ Cn 00KO CO Cn 004^ . Filtration. tn XJ xj xj poxr xj Ox a > 2 cOx p 00 ooxp KO COXJ w O OX GO to 00 CO M CH Co Co 4^ Cn XI co KO 78 ox to oxik 8^ iox 8 n" Water Filtered. to to 00-k Ox COCn xo KO w CXJ "l co to to 4^ XJ o cn oocn to S. O p 00 ( JI Cn 4- Co to CO Co 1 Jx Cn4^-COtotototo § Filtered Water Ox o XJ to XJ to Co XT Cn w Cn xj h to 4- 4- 'O Ox 00 Used for Cn o xj oo-k KO to Co ft r to OX H ooo 00 0x4- OXKO Washing. 1,2 ^4 xj xj xj xj xj Cn "b 4- bo Oxen XJ Cn Oo p xj XJ xp KO 00 Ox rt Cn XJ bo d-1 Co J XJ XJ Net Available Yield for Co •-< Ox m Q\Co Co 0X4^ t"* C/0 KO O 4- KO O xj co xj bo to to 'o m O 004^ OxXi ox Ox OxXI OX OXCn 00 00 to GO 00 00 OX M M OXXJ to KO 4^ KO Co XJ ox OXXJ Ox Oxen HH i-I O K0 CO KO KO KO 4- I ' Hours 2.6 QQXj p N po _O -k xj co to OXXI XJ <j <j 3-9 KO Co KO O p w Xj o in Service. bi KO O OxXj 4- to OX Rate of Filtration, H4 J-I r-< I-< h-1 HH HH |-( >-( Hd HH HH i-< HH hH Million Gallons o o O O O O O KO 00 HM com o m to O O io E'er Acre Daily, Vhen in Service. to Co Ox Ox Ox Ox OOCn OX 00KO Co Cn to 004^ Cn to to to to to to to M • to to to to to to to to • Net Supply, f-4 f-( o m to to m bo: co bob to bi ox to o : Per Scluare Foot HH m 00-k Cn Cn to • 00 ko O to h to coco • ot Miter, Daily, Ox Ox OX OX o io to • t-4 Cn xj -O to OOCn m • in Gallons. WATER QUANTITIES,-WARREN FILTER. 42 REPORT OF CONSULTING ENGINEER. > CD p CTQ CD cn H o cn OQ co CD > P Alarch April CD £ er 2 -i c ci p p > < CD P OQ CD tn H o p, cn 7Q 'T • '- 5 CD r ebruary ..., March April May p P o 'l 00 00 OD Ox OX 00 OXXt h 4^0 K) Oxxq Pi Pi io ox^r O Pi Pi to 00 A xi Ox x£> Pi XO Co Pi XT O « A h'C A 00 CO XVASH WATER,- • CO Co to CO do O 00 OXA O 00 OXCn Cn tO \O M A to CO CO to CO CO .o A A hh Oocn A 'oo'O xo Co XO Pi Number of Times Washed. Number of Minutes. Ox 00 00 xj xj OcnA O A *h A XJ Oxen W o O W E A 00 00XJ Ox O Ox to VJ X4 00 oxen O XJ co M ooco 'ox Gallons Per Minute. px *O O px px p\ OxCn A CO A Ox Ox Ox 00 A Ox xo hh M Ox O Ooxj M A on O CnOOi Co A OXA Co to Pi A A to O A xc u Pl E Ox do xo to >• C* do bo OX o Ox O' XO A OX px px _OxA Co Oxdo boon Cn XO to to N H H H O 00 to Cn CO O O to XJ OxA M O CO OxCn Cn A OX tO Pi OO O Gallons Per Minute Per Square Foot of Filter Area. Thou- W > sand 2- S-n Gals- „.^2 n o Tjtn Million "S 3 ~ Gallons ' 2 Per Acre.® g.p CO OX XI Cn CO ChA A to A dx boco Ox 00 bo co bo to 5-i i-4 5-i i-3 CO vb to to to co co A bx bxcn bo bo p JI W H M bo w co di bo Wash. £ 2, o Waste. S WASH WATER,-WARREN FILTER. RESULTS FROM EXPERIMENTAL FILTERS. 43 SULPHATE OF ALUMINA, WARREN FILTER. Month, 1898. Pounds Used During Month. GRAINS PER Water Treated. GALLON COMPUTED 0: Water Filtered. N QUANTITY OF Net Supply. January . .. . 1.17 1.19 1-25 February . .. 701 O.69 0.70 0.74 March .... 2,183 1.78 1.8l 1.87 April 1,166 O.85 0.86 0.88 May 2,100 i-5i i-55 i.6o Tune 1,587 i-34 1.36 1.42 July 1,692 i-43 1.46 i-54 August .... 2,798 i-73 1.76 1.85 Total 12,543 .... .... .... Averages . .. 1-36 1-38 1-44 SULPHATE OF ALUMINA,- -JEWELL FILTER. January ... . 62 0.72 0.72 0.80 February . .. 489 0.56 0.56 0-59 March .... 1,204 I.O7 1.07 1.12 April 6lO 0-54 0-54 0.56 May I,l82 I.OI I.OI 1.05 June i,324 1.18 1.18 1-25 July 1423 i-3i 131 1.41 August .... 1,521 i-35 i-35 i-44 ■ - « - Total 7,815 .... Averages . .. I.OI I.OI 1.07 Composition of Allegheny River Water Before and After Passing Mechanical Filters, for the Seven Months, Ending August, 1898, with Results from Sand Filters for the Same Period. ALLEGHENY RIVER. MECHAN'I . FILTERS. SAND FILTERS. River Gate EFFLUENTS. Warren Jewell Settling EFFLUENTS. Sample. Sample. Filter. Filter. Basin. No. 1. No. 2. Turbidity 0.20 0.004* 0.002* 0.14 O.OIO 0.012 Color . 0.26 0.26 0.03 0.03 O.24 0.07 0.07 Alkalinity 2.44 2.56 1.6l I.72 2.49 3-53 3-56 Solids 15-4 15-0 9-3 9-5 "•9 10.8 10.6 Suspended 5-3 4.9 0.0 0.0 1-7 0.0 0.0 Hardness 3-21 3-31 2.92 3-03 3-27 4-31 4-33 Chlorine . 1.87 i-73 1.71 1.71 1.80 1.84 i-77 Sulphuric Acid . 1.15 1.17 1.80 1.67 1.10 i-i5 1.15 Iron , 0.0320 0.0448 0.0058 0.0053 0.0373 0.0111 0.0145 Nitrogen as,- Free Ammonia 0.0020 0.0022 0.0019 0.0018 0.0020 0.0018 0.0018 Albuminoid Am'nia O.OIOI 0.0100 0.0047 0.0044 0.0092 0.0054 0.0053 Nitrates 0.0568 0.0611 0.0512 0.0491 0.0581 0.0642 0.0549 Nitrites 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 Bacteria ",337 11,258 201* 293* 9,224 106 148 * Excluding inferior results obtained during special experiments. 44 REPORT OF CONSULTING ENGINEER. RESULTS WITH SAND FILTERS. Necessity of Preliminary Sedimentation. Two sand filters were constructed and one sedimentation basin. One filter was supplied with the water as pumped from the river, and the other with similar water after passing through the sedimen- tation basin. During the first three months of their use the river water had uniformly low turbidities, and the filters gave equally good results in all respects. Afterwards turbid waters were obtained from the river more frequently, and with the appearance of the greater turbidities a marked difference in the behavior of the two filters was observed. The filter supplied with settled water operated for longer periods between cleanings, and gave a much more satisfactory effluent than that supplied with raw water. At times of maximum turbidity the filter supplied with unsettled water became clogged so rapidly that grave difficulties would be experienced in cleaning filters in a municipal plant operated in this manner. The bacterial efficiency was also materially less than that of the filter receiving settled water, although the settling itself removed but few of the bacteria. The experiments thus demonstrated that for the Allegheny River water preliminary sedimentation, if not absolutely necessary, is certainly desirable, and either that or its equiva- lent must be considered as an essential part of a filtration plant. Necessity of Covering Filters. In severe climates it is necessary to cover filters as a protection against frosts. In warmer climates this is unnecessary. In Europe it has been found that in those cities where the winters are so severe that the normal January temperature is below 32 degrees, Fahrenheit, it is generally necessary to cover filters as a protection against frost, while in places where the winters are less severe, covers are unnecessary. American experience is as yet somewhat limited, but the experience with open filters at Lawrence and Poughkeepsie has indicated that for America also the above statement is approximately correct. There are apparent exceptions to this rule in several cases where raw water is drawn from deep reservoirs or wells, and has always a temperature somewhat above the freezing point. In these cases open filters operate successfully in colder climates than the above limit. The normal January temperature at Pittsburgh is about 320, and is so close to the limit as to leave it uncertain whether covers arc neces- sary or desirable. To throw light upon this subject our experimental filters were left open, and were operated throughout the winter without protection from cold. Their efficiencies during the period of greatest cold fell materially below the efficiencies obtained at other periods of RESULTS WITH SAND FILTERS. 45 the year. The decrease in efficiency was greatest in the filter receiving raw water; but as sedimentation basins are considered as a necessary part of a sand filtration plant for Pittsburgh, we may confine our attention to the results obtained from the filter receiving settled water. The bacterial efficiency in September and October, and the early part of November, was exceptionally high. The monthly average for November shows a drop to 98.58, but this decrease was due to a defect in the construction of the filter, which is described in detail in the report of the Resident Engineer. Excluding the results for one week, the bacterial efficiency for November was 99.44 per cent., which is quite normal. In December the bacterial efficiency fell to 98.88; in January to 97.82; and in February, which was the coldest month of the season, to 97.18. Afterwards the efficiency rapidly improved, and remained at about or above 99 per cent, for the remainder of the time covered by our experiments. It will thus be seen that while the efficiency for the winter months was less than at other times, it did not fall below an average of 97 per cent.; and it may be that this efficiency will be satisfactory for the con- ditions at Pittsburgh. It is probable, further, that in an actual plant, by improved manipulation, the reduction in efficiency will be less than it was in the experimental plant, although sometimes colder weather would occur than any during the past winter. The most important point to be observed in operating filters in winter is to clean the filters in weather that is not too cold, and to prevent the sand from freezing while exposed to the air. The experimental filters were always cleaned when they became clogged, or directly afterward, and the sand became frozen on several occasions, with the result of decreasing the efficiency as above shown. With a sufficient reserve area it would be possible generally to wait for a few days, if necessary, for warmer weather before cleaning, and consequently there would be less disturbance in the normal action of the filters. The experimental filters were kept up to their nominal delivery regardless of the weather. The winter disturbances can, if necessary, be entirely eliminated by the construction of covered filters at an additional expense as stated in connection with the estimates of cost; but I do not regard this as necessary, and do not recommend it. Effect of the Mud, Crude Petroleum, Mine Waste, etc., upon Sand Filters. The Allegheny River receives at times a great deal of crude petro- leum and coal-mine waste. These substances are not generally present in other river waters which have been successfully filtered. It was thought that these substances might have some effect upon the operation of the REPORT OF CONSULTING ENGINEER. 46 filters which would materially influence the results obtained. In the course of our experiments no such disturbing action has been present. The effect of excessive quantities of mud in the raw water has been generally recognized. The most obvious effect is to shorten the period between scrapings, making cleanings more frequent and expensive. It is also noticed that when the turbidity of the water applied to the filters is very high some of it passes through the filter, and turbid effluents result. This is particularly the case at high rates of filtration. During the months of July and August, 1898, Filter No. 2 was operated at a rate of five million gallons per acre daily. During a part of this time the river water was very muddy, and the effluent from the filter operating at the five million rate became four times as turbid as that operating at a three million rate. The turbidity of the effluent at the five million rate reached 0.07, a point which would be seriously objectionable to the water takers. The highest turbidity reached at this time with the filter operated at the three million rate was 0.02, a turbidity which is just visible in an ordinary drinking glass, and which would not be seriously objectionable to any one. At the time of the spring freshets, with very high and continued turbidities in the raw water, when filtering at a three million rate, effluents with turbidities of from 0.03 to 0.06 were obtained for four days. It is believed, however, that in practice filters could be so operated as never to produce effluents of this degree of turbidity. Owing to the fact that the consumption at such times is generally less than the average, there is a large reserve filtering area and somewhat lower rates of filtration could be employed. Further, the quantity of water stored in the system of reservoirs is considerable, and could be safely drawn upon for part of the supply for the short periods at which these very high turbidities occur. By reducing the rate of filtration somewhat at these times, it is believed that the turbidity can always be kept within limits which will not be objectionable to any one. RESULTS WITH SAND FILTERS. 47 Frequency of Scraping Sand Filters. Filter No. 1, receiving settled water, was scraped during the period covered by our experiments fourteen times. The quantities of water passed between scrapings and the depth of sand removed were as follows : Date. 1897. Number of Period. Quantity of Water Filtered, Million Gallons Per Acre. Depth of Sand । Removed in Feet. Average r Turbidity of Applied Water. July 24 to August 17 . . . . I 45-o 0.04 0.20 August 18 to October 9 . . . 2 136.0 0.06 0.06 October 10 to November 11... . • • • 3 104.2 0.05 0.03 November 18 to December 8. . . • • • 4 61.7 0.05 0.21 December 9 to December 28. , 5 56.1 0.13 0.15 1898. December 30 to January 11. .. . 6 38-4 0.03 0.08 January 12 to January 25 7 38.5 0.05 0.21 January 26 to February 7 ... 8 35-2 0.10 0:10 February 8 to March 10 •• 9 9i-3 0.07 0.10 March 11 to April 7 ... 10 80.1 0.12 0.12 April 8 to May 10 .. 11 102.3 0.07 0.06 May 11 to June 16. .. .• ,.. 12 102.9 0.07 0.10 June 17 to July 18 . .13 94-o O.O9 0.13 July 19 to August 19 . . .14 94-3 0.13 0.21 Averages 77-i O.O76 The loss of head was, in general, limited to about four feet. In the first two periods the loss of head was allowed to reach a considerably higher figure, and in these cases only the quantities have been taken which were filtered before the loss of head reached four feet. The average quantity of water filtered between scrapings was 77,000,000 gallons per acre with a loss of head of four feet. Filter No. 2 was operated for about nine months with raw water and four months with settled water, and the average period was 57,000,000 gallons per acre filtered between scrapings. This result, however, is of no value for the purpose of our computations, as the procedure adopted was not that which would be adopted in a municipal plant. The period obtained with No. 1 is rather higher than the average of German results, and is about the same as the average period of the London Water Companies. It is somewhat greater than has been obtained at Lawrence, Mass., with the Merrimac River water, and about the same as that obtained at Mount Vernon and Poughkeepsie, N. Y. The German results are low because the loss of head is limited in general to about two feet instead of the four feet used at Pittsburgh, and the Lawrence results are low owing to the peculiar construction of the filter. At Pittsburgh the 48 REPORT OF CONSULTING ENGINEER. results indicate that the cost of operation of filters will be quite as moderate as compared with the costs in other places. results with mechanical filters. The principal problem to be solved in connection with mechanical filtration was to determine the bacterial efficiency which could be secured and the conditions which control it. The filters were not put in operation until January, 1898, owing to various delays in the arrangements with the mechanical filter companies and in the manufacture of the apparatus, over which we had no control. The filters were in good working order by the first of February, and the monthly results from that date are given in the above table.* In general the filters were operated in accordance with suggestions of the filter companies, and in such a manner as to give the best possible effluents obtainable under ordinary working conditions. It soon became apparent that the amount of sulphate of alumina employed was more important than any other factor in determining the bacterial efficiency, and it was thus important to establish the effect of more and of less coagulant than was used in the ordinary daily work. Special experiments in this direction were made upon the Warren Filter during May, and with the Jewell Filter during June. The monthly averages for these months are thus abnormal, and are not to be con- sidered. The remaining six months may be taken as normal and as representing approximately the work of these filters under ordinary care- ful working conditions. During the six months when the Warren Filter was in normal order the raw water contained 11,531 bacteria and the effluent 201, the average efficiency being 98.26 per cent. The bacterial efficiency was very con- stant, ranging only, by months, from 97.48 to 98.96 per cent. During the same months Sand Filter No. 1 yielded an effluent having 105 bacteria per cubic centimeter, or one-half as many as the water from the mechanical filter. This period for Filter No. 1 included the month of February, which was the month when the greatest decrease in efficiency from cold was observed. The Jewell Filter, for the six months in which it was in normal order, received raw water containing an average of 11,481 bacteria, and yielded an effluent containing an average of 293, the bacterial efficiency being 97-45 per cent., and ranging, in different months, from 93.23 to 98.61 per cent. Sand Filter No. I for the same months yielded an effluent con- taining 101 bacteria per cubic centimeter, or a little more than one-third as many as the effluent from the Jewell Filter. The number of bacteria * See Page 40. RESULTS WITH MECHANICAL FILTERS. 49 passing the mechanical filters was thus on an average two or three times as great as the number passing the sand filters. Wasting Effluent after Washing Filters. After washing a mechanical filter the effluent for the first few minutes is often inferior in quality to that obtained at other times, and if samples are taken at these times and averaged with other samples taken during the run, an apparent efficiency may be obtained inferior to the true efficiency. To guard against this source of error, whenever samples have been taken at such times, the average work for the day has been taken not as the numerical average of the results, but each sample has been given weight in proportion to the amount of time which it could be taken as representing; so that the results represent as nearly as possible the average number of bacteria in the effluent for the whole run. As a matter of fact, however, comparatively few samples were taken during those periods of reduced efficiency, and thus most of the results represent the normal efficiency exclusive of this period. A study has been made, however, of the results of examinations of samples taken directly after washing, somewhat in detail. The following is a tabular statement of the average results obtained from each filter by months, including only the results obtained on those days when samples were taken within twenty minutes after washing, the results of other days being excluded:- AVERAGE NUMBER OF BACTERIA IN EFFLUENT. WARREN FILTER. Shown by Record Sheets. Within 10 Minutes After Washing. 11 to 20 Minutes After Washing. More than 20 Minutes After Washing. February 115 • • . Il8 114 March 3j6 50 515 301 April 79 417 207 75 May June 197 493 272 170 July 3°° 546 207 August 174 356 6OI 223 JEWELL FILTER. February 2,453 2,425 2,099 March 455 657 958 354 April 99 665 462 165 May 144 998 346 127 June July 279 F33O 272 274 August 344 6l2 323 376 REPORT OF CONSULTING ENGINEER. 50 The time of inferior work very rarely exceeded twenty minutes. It will be seen from the tables that the results as shown by the record sheets are never very much higher, and are occasionally lower than the results of samples taken on corresponding days more than twenty minutes after washing; and thus while a decrease in bacterial efficiency was noted after washing, no material increase in the average bacterial efficiency of the mechanical filters would have been obtained if these results had been ex- cluded. The results for the whole time would be affected much less than is indicated by the table, because the table includes only results of those days when samples were taken just after washing, while the much larger number of days when no such samples were taken would show no change whatever. It has been suggested that these inferior effluents after washing should be wasted. Such a procedure would mean wasting probably on an average two per cent, of the water filtered, and a corresponding in- crease in the cost of filtering. Mr. Fuller1 in his Louisville Report comes to the conclusion that with adequate washing and coagulation it is unnecessary to waste any effluent, and that inferior results after washing usually indicated incomplete washing. While our experiments certainly indicate a reduction in efficiency after washing so regular and persistent as to make it doubtful whether incomplete washing can be the cause of it, it may be questioned whether or not wasting the effluent would be necessary or desirable in actual operation. At any rate, the results as given in this report are not materially influenced by this factor. Influence of Amount of Sulphate of Alumina on Bacterial Efficiency of Mechanical Filters. * The number of bacteria passing a mechanical filter is dependent principally upon the amount of sulphate of alumina used, and by using a larger quantity of sulphate of alumina than was actually used in the experiments the bacterial efficiency could be considerably increased. To investigate this point, the results obtained each day with each of the mechanical filters were arranged in the order of the sulphate of alumina quantities used, and averaged by classes. In this and the following tables a few abnormal results were omitted.2 A summary of the results is as follows:- 1 Fuller:-Water Purification at Louisville; Page 425. 2Warren,-Feb. 9, June I, July 6. Jewell,-July 1, Feb. 9, 16, 17. RESULTS WITH MECHANICAL FILTERS. 51 SUMMARY OF RESULTS WITH WARREN MECHANICAL FILTER. ARRANGED ACCORDING TO SULPHATE OF ALUMINA QUANTITIES. a> Ln Ln KO CL Ln 4-. 4^ O KO CL O CL Ln oo o KO 00 to 4^ to 2^ Qg S' M O o o O O O O O O p O o o o o O o O o O o o H c b -p O\cn -k to O Co to Ln Ln KO 00CO to to CL O m GO tO M O « OKKO O o o o to Ok OK OK O o o o OOLn & cl to CL KO COLO l-H to M 4- Ok to Ok 10 o to o 00 OKLn Cl CL OOLn to W b cl CL O o o to OOLn KO 10 CL XI Ln to co o o to Ok to O 004- Cl Ln OkkO h ton XI KO C0XJ Ok Ok w 4^ O XT O OK4^ to XI w Xi GO 10 m O CL 004^ CL KO "co xi Ln CL Water. > M W W ► Cn m Ln \O KO Ln to CO 347 86 KO O Ok Ok 10 O 4- •- to o o ts "ob to Cn to CL to to >-i XI CO XI tOLn -• OK O CL 3 c 3 rJ p Cl O p Ok OOLn hh to to o m p p Ln tO KO KO 00 P O p -P OOLn QOOJ CL to to O KO KO to N Cn to « M to XT 00 XI M 4- w CL CL CL p to CL O io CL bo KO Per Cent. Remaining. KO KO KO KO KO KO KO KO KO KO KO KO KO KO KO KO KO KO KO KO 00 OK OK 00 OKKO 00KO 00 00KO KO 00 00KO 00X1 00 00 XI OKOKXILnKO4^ W *-d n a s CL m Ln 004^ XI CO 00 O KO hh m OOLn to to xi xi o OOLn O 4- to to 00 00KO Ok KO CL Cn KO a HH c O < rt O *3 00 CL b co O\ XI tO M -k KO 00 10 boxr ^OKLn 4- cl Ok 4- Jo CL Jo O KO CL O O Jcoxi O O O p p CL 10 OK OK p to o b O 0 n> g 5'p o • tn SUMMARY OF RESULTS WITH JEWELL MECHANICAL FILTER. ARRANGED ACCORDING TO SULPHATE OF ALUMINA QUANTITIES. Number of Days Repre- sented. Turbidity. BACTERIA. Per Cent. Remaining. Per Cent. Removed. Sulphate of Alumina Used, Grains Per Gallon. Raw Water. Effluent. 6 0.03 14,037 6,217 44-29 55-7i 0.00 5 0.07 4,267 680 15-93 84.07 0.24 14 0.06 2,613 170 6.50 93-50 0-35 10 0.06 2,446 113 4.62 95-38 0.44 9 O.II 7,303 234 3-20 96.80 0.55 20 O.O9 6,979 220 3-i5 96-85 0.65 9 0.08 5J9I 130 2.50 97-50 0.75 16 O.I2 8,504 242 2.84 97.16 0.83 22 O.l6 8,506 99 1.16 98.84 0.96 12 O.II 11,998 246 2.05 97-95 1-05 14 O.l8 18,982 423 2.23 97-77 1.16 5 O.I4 13,981 224 1.60 98.40 1-23 9 O.27 19,806 325 1.64 98-36 i-34 14 O.27 16,549 324 1.96 98.04 i-45 9 O.29 12,194 96 o-79 99.21 i-54 6 0.25 13,483 5i 0.38 99.62 1-65 7 0-53 24,243 220 0.91 99-09 1.72 3 O.9O 20,953 602 2.88 97-12 1.90 ■ 5 0-43 25,958 307 1.19 98.81 2.19 4 O.84 21,017 228 1.09 98.91 3-7i These results are shown graphically on the accompanying diagram.* fer * See Plate No. 7, opposite Page 52. 52 REPORT OF CONSULTING ENGINEER. Influence of Degree of Turbidity upon Bacterial Efficiency of Mechanical Filters. It will be noticed by referring to the tables that as the sulphate of alumina quantities increased the turbidities increased and the numbers of bacteria increased, as well as the bacterial efficiencies. That is to say, with the less turbid waters, small sulphate of alumina quantities have been used, the numbers of bacteria in the raw water have been low, and the bacterial efficiencies have also been low. With turbid waters much larger quantities of sulphate of alumina have been used, the raw water has contained more bacteria, and the bacterial efficiencies have been much higher. It may be then, that the increased efficiencies with increased quantities of sulphate of alumina are not due alone to the increased sulphate of alumina, but in part also to other conditions. Thus it may be easier to remove a large percentage of bacteria from a water containing many than from a water containing only a few. To investigate this matter and eliminate the influence of turbidity and numbers of bacteria in the raw water, the results were first classified with reference to turbidity. The results with waters having turbidities of o.io or less, and called for convenience turbid waters, are arranged by alum quantities as before. Afterwards the results obtained with turbidities from o.n to 0.50, and called for convenience muddy waters, are grouped; and finally the results with waters having turbidities of 0.51 and over, and called for convenience thick waters. The results thus arranged are as follows :- SUMMARY OF RESULTS WITH WARREN MECHANICAL FILTER. ARRANGED ACCORDING TO TURBIDITIES AND SULPHATE OF ALUMINA QUANTITIES. Number' of Days Repre- sented. Turbidity. BACTERIA. Per Cent. Remaining. Per Cent. Removed. Sulphate of Alumina Used, Grains Per Gallon. Raw Water. Effluent. 7 0.05 4773 1,713 35-89 64.II 0.00 2 0.07 2785 850 30.52 69.48 0.12 12 0.06 3,209 224 7.00 93-00 0.42 31 0.06 4,238 119 2.8l 97-19 0.60 9 0.06 7,953 130 I.64 98-36 O.84 16 0.04 11,265 137 1.22 98.78 I.II 29 0.06 11,500 158 1-37 98-63 1-58 5 0.17 8783 416 . 473 95-27 O.36 10 O.l6 6,535 165 2-54 97-46 0.85 13 0.19 13753 186 1.40 98.60 II3 15 0.22 10,944 93 0.85 99-15 I.36 13 O.29 14,089 112 0.80 99.20 1-73 10 o-35 18,088 102 o-57 99-43 2.38 5 0.29 25,580 540 2.11 97-89 4-30 6 0.87 25,433 369 i-45 98.55 i-74 6 o-73 26,566 79 0.30 99-70 2.64 4 i-35 42,037 1,388 3-30 96.70 8.16 P late No. Z )00 Per Cent of Bacteria Removed CITY OF PITTSBURGH FI LT RATION COMMISS10 N BACTERIAL EFFICIENCIES OF MECHANICAL FILTERS WITH VARIOUS QUANTITIES OF SULPHATE OF ALUMINA Sulphate of Alumina used in grains per gallon. RESULTS WITH MECHANICAL FILTERS. 53 SUMMARY OF RESULTS WITH JEWELL MECHANICAL FILTER. ARRANGED ACCORDING TO TURBIDITIES AND SULPHATE OF ALUMINA QUANTITIES. Number of Days Repre- sented. Turbidity. BACTERIA. Per Cent. Remaining. Per Cent. Removed. Sulphate of Alumina Used, Grains Per Gallon. Raw Water. Effluent. 6 0.03 14,037 6,217 44-29 55-71 0.00 3 0.07 5,170 991 I9-I5 80.85 0.21 25 0.05 2,403 U3 5-95 94-05 O.38 20 0.06 6,531 185 2.84 97.16 O.64 27 0.06 5,8h 122 2.10 97-90 0.88 14 0.06 14,978 412 2-75 97-25 1.11 10 0.06 15,787 390 2-47 97-53 i-37 10 O.O5 10,847 47 0-43 99-57 2.17 14 O.l6 7,525 256 3-40 96.60 0.60 17 0.24 H,3I0 208 1.84 98.16 0.91 15 0.24 15,441 262 1.70' 98.30 I-I3 10 0.28 17,842 232 1-30 98.70 i-43 8 0.29 9,556 59 0.62 99-38 i-59 4 0.29 20,212 i35 0.67 99-33 2.00 5 0.66 23,680 336 1.42 98-58 1.42 7 0.96 30,200 475 i-57 98-43 i-74 4 1-25 37,587 496 1-32 98.68 2.81 The following table shows the bacterial efficiencies with turbid, muddy and thick waters, with substantially equal quantities of sulphate of alumina:- GRAINS O1 Turbid. 7 SULPHATE OF Al Muddy. LUMINA. Thick. CORRESPOND Turbid. •ING BACTERIAL EF Muddy. FICIENCIES. Thick. 0.42 0.36 93-00 95-27 0.84 0.85 98-36 97-46 I.II 1.13 98.78 98.60 1.58 i-73 i-74 98-63 99.20 98.55 2.38 2.64 99-43 99-70 4-30 8.16 97-89 96.70 JEWELL FILTER. 0.64 0.60 97.16 96.60 0.88 0.91 97-90 98.16 1.11 i-i3 97-25 98-30 i-37 i-43 1.42 97-53 98.70 98.58 2.17 i-59 i-74 99-57 99-38 98.43 2.00 2.81 99-33 98.68 WARREN FILTER. It appears from this table that waters of various degrees of turbidity give substantially equal bacterial efficiencies with equal quantities of sul- phate of alumina, the results varying as often in one direction as the other. Within certain limits it may thus be said that turbidity is without influence upon the bacterial efficiency obtained in mechanical filtration. It must be borne in mind, however, that the quantities of sulphate of alumina, with very few exceptions, were sufficient to produce full coagula- 54 REPORT OF CONSULTING ENGINEER. tion. Mr. Fuller has shown in his Louisville Report that considerable quantities of sulphate of alumina may be added to turbid waters without producing appreciable coagulation, and therefore if a quantity of sulphate of alumina sufficient to produce a certain bacterial efficiency in a clear water should be added to a water so turbid that it was unable to coagulate it, scarcely any effect would be produced. The above statement therefore only applies in those cases where sufficient sulphate of alumina is used to adequately coagulate the water. As the numbers of bacteria often vary with the turbidity, the variation in the numbers of bacteria in the different classes is much less than in the first tables; but to further investigate the question of whether the numbers of bacteria in the raw water have an important influence upon the bacterial efficiencies, each of the two largest classes in the foregoing tables were divided into two parts, according to the bacterial numbers in the raw water, namely, the results from the Jewell Filter with turbid waters and with sulphate of alumina quantities ranging from 0.75 to 1.00 grain per gallon, and the results from the Warren Filter with turbid waters and with sulphate of alumina quantities of 1.25 grains per gallon and upward. The results are as follows:- Number of Days Repre- sented. Turbidity. BACTERIA. Per Cent. Remaining. Per Cent. Removed. Sulphate of Alumina Used, Grains Per Gallon. Raw Water. Effluent. 14 0.05 3,938 8l 2.06 97-94 0.88 13 0.07 7,827 167 2.13 97-87 0.87 JEWELL FILTER. WARREN FILTER. i5 o.o6 3-545 59 1.66 98-34 1.67 14 0.06 20,022 265 1-32 98.68 1.48 It will be observed that the bacterial efficiencies are substantially the same, with the lower and with the higher numbers of bacteria in the raw water. That is to say, other things being equal, as the number of bacteria increase in the raw water the number of bacteria in the effluent increase in the same ratio. A further analysis of other groups of results would perhaps show variations in one direction or the other, but on the whole it is believed that the comparison is a fair one, and that there is no well marked tendency for bacterial efficiencies of mechanical filters to increase or decrease with increasing numbers of bacteria. Average Re salts Obtained with Various Quantities of Sulphate of Alumina. As it appears that neither the turbidity nor the number of bacteria in the raw water have a material influence upon the percentage of bacterial efficiency obtained, we can take the results given above, which include all the results obtained (except a very few abnormal ones) for computing AMOUNT OF SULPHATE OF ALUMINA REQUIRED. 55 the various efficiencies obtained with various quantities of sulphate of alumina. These results are graphically shown on the accompanying diagram, on which lines have been drawn indicating the normal efficiencies from various quantities of sulphate of alumina as deduced from our experiments.1 In computing the amount of sulphate of alumina which it would be necessary to use in operating a plant at Pittsburgh to give these efficiencies, the quantities of sulphate of alumina shown by the diagram can be taken as those which it would be necessary to use during those days in the year when the raw water was clear, or sufficiently clear, so that the amounts of sulphate of alumina mentioned would suffice to properly coagulate it. Amount of Sulphate of Alumina Required to'Clarify Turbid Waters. With the most turbid waters certain quantities of sulphate of alumina are required for coagulation, irrespective of bacterial efficiency. In order to determine these amounts of sulphate of alumina, all the results with raw water turbidities of 0.10 and over have been arranged by themselves, and have been plotted on the accompanying diagram.2 It should be remembered'that many of the quantities of sulphate of alumina shown on this diagram were used to secure high bacterial efficiencies and without reference to the turbidity, and therefore the minimum rather than the average amounts should be considered. On the other hand, the quantities of sulphate of alumina were occasionally insufficient to produce entirely clear effluents. Bearing these facts in mind, lines have been drawn representing the amounts of sulphate of alumina which it may be considered necessary to use with the Warren and Jewell Filters with the turbidities given to produce, in general, clear effluents. These lines start at 0.30 of a grain of sulphate of alumina for perfectly clear waters, and reach 2.00 grains with the Jewell and 2.75 grains with the Warren for turbidities of 1.00. No doubt the amount of sulphate of alumina required to clarify turbid waters depends some- what upon the character of the material causing the turbidity; but the lines as drawn will be sufficiently accurate for the purposes of present computations. Amount of Sulphate of Alumina Which Must Be Used. If now we take the various efficiencies obtained with the various quantities of sulphate of alumina from the first plotting, and assume that these quantities of sulphate of alumina will be sufficient to clarify all waters up to the turbidities corresponding to these quantities, as shown by the second diagram, and th^i for the remaining days of the year 1 See Plate No. 7, opposite Page 52. 2 » « U 8> .« .. 56. 56 REPORT OF CONSULTING ENGINEER. assume such larger quantities as will be sufficient to remove the sediment, as shown by the second diagram, we have the following results:- WARREN FILTER. Required Bacterial Efficiency. Sulphate of Alumina Required for this Bacterial Efficiency with Least Turbid Waters. This Quantity of Sulphate of Alumina is Sufficient for the Treatment of W aters With Turbidities up to Extra Sulphate of Alumina Quantity for Higher Turbid- ities Reckoned on all the Water Treated for One Year. Average Quan- tity of Sulphate of Alumina Required, Grains Per Gallon. 95-oo o-37 0.03 o-33 O.7O 96.00 0-44 O.O6 0.28 0.72 97.00 0.56 O.II 0.22 O.78 98.00 0.84 0.22 0.14 O.98 98-50 1.12 0-34 0.10 1.22 99.00 1.60 0-53 0.06 1.66 JEWELL FILTER. 0.18 0.60 95-oo 0.42 0.07 96.00 0-49 0.12 0.15 0.64 97.00 0.65 0.21 0.10 0.75 98.00 0.96 0-39 0.06 1.02 98-50 1.48 0.70 0.02 i-5o In the following table are shown the average quantities of sulphate of alumina which it will be necessary to use with the Warren and Jewell Filters to produce at all times ordinarily clear effluents, and to get average bacterial efficiencies, as shown in the first column. A third column has been added giving results between the Warren and Jewell, which results will be used for further computations in regard to the cost of operation of mechanical filters. QUANTITIES OF SULPHATE OF ALUMINA REQUIRED TO PRODUCE CLEAR EFFLUENTS, AND THE BACTERIAL EFFICIENCIES MENTIONED. Bacterial Efficiency. Required with Warren Filter. Required with Jewell Filter. Used in Computation of Cost of Operation. 95-oo O./O 0.60 0.65 96.00 O.72 O.64 0.68 97.00 O.78 o-75 0.76 98.00 O.98 1.02 1.00 98.50 1.22 i-5o i-35 99.00 1.66 (i-7o) Action of Sulphate of Alumina and the Quantity of Sulphate of Alumina Which Can Be Safely Used. All calculations thus far have been based upon the assumption that it is possible to use any quantity of sulphate of alumina which may be desired. As a matter of fact this is not the case, but the amount which can be used is dependent upon the amount of lime in the raw water. When sulphate of alumina is added to water it is decomposed, with the formation of alumina, which forms a flocculent precipitate, upon which its purifying action depends, and sulphuric acid which combines with the P I ate N o. 8. Sulphate of Alumina in grains per gallon. WarrenJSk 'ter Jewel/_ Fitrer_ CITY OF PITTSBURGH FILTRATION COMMISSION AMOUNTS OF SULPHATE OF ALUMINA ACTUALLY USED WITH MECHANICAL FILTERS WITH WATERS OF VARIOUS DEGREES OF TURBIDITY AND THE AMOUNTS NECESSARY FOR CLARIFICATION. Turbidity of Raw Water. ACTION OF SULPHATE OF ALUMINA. 57 calcium carbonate or lime present in the raw water. There should always be an excess of lime in the water. If, however, for any reason there is not, there is nothing to combine with the sulphuric acid, and the decomposition of the sulphate of alumina is not complete, and a portion of it goes undecomposed into the effluent. The effluent then has an acid reaction and is unfit for domestic water supply. When distributed through iron pipes it attacks the iron, rusting the pipes, and giving rise to all the disagreeable consequences of an iron-containing water. The amount of lime in the water at any time available to combine with the sulphuric acid can be determined by a very simple chemical operation, and has been so determined at frequent intervals during the course of our experiments. The amount of. sulphate of alumina cor- responding to a given quantity of lime can be readily and accurately calculated, but it is not regarded safe to use as much sulphate of alumina as corresponds to the lime. The quantity of sulphate of alumina used is not susceptible to exact control, but fluctuates somewhat; and if the exact theoretical quantity should be employed during twenty-four hours, there would surely be an excess during some portion of that time, from which bad results would be experienced. It is therefore considered only prudent to use three-fourths as much sulphate of alumina as corresponds to the lime in the water. The following table shows the average alkalinity or uncombined lime of the Allegheny River, and the amount of sulphate of alumina in grains per gallon which could be safely used with it. The sulphate of alumina is computed as having seventeen per cent, soluble alumina, that being the average strength used in our experiments. Month. 1897. Alkalinity Expressed as Calcium Carbonate. Parts Per 100,000. Safe Amount of Sulphate of Alumina, Grains Per Gallon. ■August 4-05 379 September . .. 4-63 4-34 October .... 5-09 477 November . . . 3-51 3-29 December . . 1.72 1.61 1898. January .... 1.48 i-39 February . .. . i-73 x I.62 March i75 1.64 April 1-83 1.72 May 2.12 1.99 June 3-io 2.90 July 3-41 3-20 August 3-i5 2-95 Averages for Year, end- ing July 31, 1898. .. .2.87 270 58 REPORT OF CONSULTING ENGINEER. The alkalinity, and consequently the amount of sulphate of alumina which can be used, is, in a general way, inversely proportional to the amount of water flowing in the river. When the river is low in summer, the water carries a great deal of lime; while in winter, and especially in the spring freshets, it is made up largely of melted snow and rain water and carries but little lime. The lowest monthly average is for January, corresponding to 1.4 of a grain of sulphate of alumina to the gallon. For short intervals during floods, alkalinities considerably lower than the monthly averages were obtained during January, February, March, and April, the amounts being so low at times as to be only capable of decomposing one grain of sulphate of alumina to the gallon. Mr. Fuller in the report of his experiments at Louisville has called attention to the fact that with very large amounts of suspended matter more sulphate of alumina can be used then corresponds to the alkalinity of the water. The explanation of this is apparently that some of the sulphate of alumina is absorbed by the clayey matter in suspension, and carried out as sulphate of alumina without being decomposed, and without taking up any of the lime in the raw water. It may be questioned whether the sulphate of alumina which has been absorbed in this way plays any part whatever in the purification. It allows the use of more sulphate of alumina than would otherwise be possible, however, and must thus be taken into consideration. Mr. Fuller* states as the results of his experiments that the percentages which the actual reductions in alkalinity by sulphate of alumina were of the theoretical percentages with the Ohio River water containing different amounts of suspended matter were as follows :- Suspended Matter in Parts Per Million. Percentages which the Actual were of the Theoretical. 200 85 400 80 800 75 1,200 65 The suspended matters in this table represent approximately the range during the freshet flows of the Allegheny River at Pittsburgh, and it may therefore be assumed that at these times the reductions in alkalinity will be about as given in the table; or putting it in another way, the amount of sulphate of alumina used may be increased from twenty to fifty per cent, above the amounts corresponding to three-fourths of the alkalinity. Making this allowance, it appears that at times the amount of sulphate of alumina which can safely be used with the Allegheny River water is not more than 1.2 to 1.5 grains per gallon. These times of minimum alkalinity are also, in general, times of maximum turbidity, * Water Purification at Louisville, Page 54. SAFE AMOUNT OF SULPHATE OF ALUMINA. 59 and the quantity of sulphate of alumina necessary for clarification is occasionally greater than the amount which can be safely taken by the water. During the course of our experiments, and before this condition was fully realized*, the amount of sulphate of alumina was, on several occa- sions, increased beyond the amount which could properly be received by the water, in the endeavor to maintain clear effluents, and acid and alum containing the effluents were the result. The effluents also were not clear at these times, and on a number of occasions turbid effluents were obtained from the mechanical filters with the best conditions which could be obtained, and in fact the conditions were such'that clear effluents could not have been obtained by the use of any amount of sulphate of alumina, large or small. These times were not of frequent occurrence nor of long duration, and would probably not prevent securing a satisfactory effluent for municipal supply, as the rate of filtration could be reduced, as with sand filters, at these periods; but owing to the absence of the large sedi- mentation basins and the large quantities of water upon the sand filters, the reduction in rate which would be possible at these times would be relatively less with mechanical than with sand filters. Another alternative would be to add lime to the water before adding the sulphate of alumina, making up the deficiency in alkalinity. In this way a much larger quantity of sulphate of alumina could be used without having it pass undecomposed into the effluent; but, on the other hand, the hardness of the water would be increased, and the process also made more complex and difficult of regulation. Soda ash could be used instead of lime, at a considerable increase in expense and without in- creasing the hardness. The use of lime and soda ash in any event should only be regarded as emergency measures during floods. The regular use of either of these substances would be attended with such disad- vantages as to render it out of the question. It will be seen that (throwing out of consideration the use of lime and soda ash) during six months of the year the water of the Allegheny River contains so little lime as Qnly to make possible the use of from 1.2 to 2.0 grains of sulphate of alumina to the gallon. The use of larger quantities of sulphate of alumina, with corresponding bacterial efficiencies, is therefore impossible for the conditions at Pittsburgh. In fact there would be several months when enough sulphate of alumina could not be used to reach 1.70 grains to the gallon with a bacterial efficiency of 99 per cent. It may thus be said that, as far as our experi- ments have developed the case, the maximum average bacterial efficiency which can be obtained at Pittsburgh by mechanical filtration is rather less than 99 per cent, with the most efficient quantity of sulphate of alumina applied to the water, regardless of the cost. 60 REPORT OF CONSULTING ENGINEER. COMPARISON OF THE QUALITIES OF EFFLUENTS OBTAINED BY SAND AND MECHANICAL FILTRATION. Bacterial Efficiency. The average bacterial efficiencies of filters on the respective systems, as developed by our tests, were an average of 99 per cent, for the sand filters, and from 97 to 98 per cent, for the mechanical filters. With the sand filters the efficiencies for the summer months, and particularly those months when the numbers of bacteria in the raw water were highest, were , very much above this average, reaching during October, 1897, the remark- able efficiency of 99.96 per cent. It is noticed throughout that the numbers of bacteria in the effluents from the sand filters vary less with changes in the numbers of bacteria in the raw 'water than do those in the effluents from mechanical filters. With the lowest numbers of bacteria in the river water a certain number are found in the effluents from the sand filters, and with the highest numbers the numbers in the effluents are often little or no greater. This circumstance, which has been observed with sand filters in many places, has led to the theory that these bacteria, within certain limits, result from growths in the underdrains and in the lower parts of the filters, and do not represent bacteria which have come through the sand. To a certain extent this deduction is correct, and it is a well established fact that the numbers of bacteria found in the effluents from sand filters represent more than the numbers which really pass the filters. With mechanical filters, on the other hand, the action is so rapid, and the filter is stirred to the bottom so frequently, that there is no chance for growths of this kind, and the numbers of bacteria found in the effluents do actually represent the numbers of bacteria passing the filters. The importance of this difference lies in the fact that the bacteria which are capable of growing in the underdrains and lower parts of the sand filters are in no case injurious to health, and as far as the bacteria in the effluents are of this character, they are unobjectionable; and as this number is added to that of the bacteria which have actually passed through the filters, and are, or may be, objectionable, the apparent efficiency of the filter is reduced below the true efficiency. The greatest numbers of bacteria in the effluents from sand filters occur during the winter, and at this time the numbers must be taken as representing, for the most part, bacteria which actually pass through, the conditions for growths in the underdrains being less favorable at this season of the year. During the winter months the bacterial efficiency fell to about 97 per cent, for a time. This reduction in efficiency would be avoided by the use of covered instead of open filters. With mechanical filters, the percentage of bacteria passing was con- siderably greater than with the sand filters. By using a larger quantity COMPARISON,-SAND AND MECHANICAL FILTRATION. 61 of sulphate of alumina than was used during our experiments, it would be possible to obtain higher bacterial efficiencies, possibly as high as 99 per cent. This would be equivalent to the average yearly work of open sand filters, but not equivalent to the work which could be secured from sand filters during summer, or from covered filters all the year round. Some special experiments demonstrated the sensitiveness of mechan- ical filters to the constant application of sulphate of alumina. When, for the purpose of experiment, the addition of sulphate of alumina to the water was interrupted, the bacteria in the effluent increased in about the length of time which was required for the water to pass through the apparatus, and in a short additional time the bacteria in effluent became a considerable percentage of those in the raw water. The im- portance of this will be at once appreciated, as in a mechanical filter plant if the sulphate of alumina applied should be interrupted at any time tem- porarily the efficiency of the filter disappears. On the whole, the bacterial efficiency of the sand filters has been very much better than that of the mechanical filters. By using more sulphate of alumina, better bacterial efficiency could be secured with mechanical filters than the average results of our experiments with them; but the efficiency which can be secured in this way would not be as great in any case as that of sand filters protected from winter weather. Clearness of Effluent. As has been shown, there are times when neither sand filters nor mechanical filters are capable of producing perfectly clear effluents from the Allegheny River water. The times when sand filters cannot produce clear effluents are more frequent and last longer than the times when mechanical filters cannot produce clear effluents, and the mechanical filters in this respect are distinctly superior to the sand filters. It is believed, however, that a plant on either system, properly constructed and operated, would yield effluents entirely unobjectionable in this respect. With sand filters, the turbidity of effluents can always be kept within 0.02 by re- ducing somewhat the rate of filtration for the short times when the turbidity in the river is exceptionally high, and this turbidity is such as not to be particularly noticeable in an ordinary drinking glass. These periods of maximum turbidity of the river water are quite short, and by drawing somewhat upon the stored water in the reservoirs at these times, the difficulties of filtration will be materially less than they were in our experiments, in which the attempt was made to maintain the full rates of filtration at all times, regardless of the character of the raw water. REPORT OF CONSULTING ENGINEER. 62 Color. The water of the Allegheny River after filtration is almost entirely colorless. It has, however, occasionally a yellow color, due to peaty matter. The origin of this peaty matter has not been traced in detail, but it appears probable that one or more of the upper tributaries of the river are of a peaty character, and that when these branches are in flood, the water from them is sufficient to color slightly the water of the river at Brilliant. At these times a considerable portion of the color passes through the sand filters, but is removed by the action of the sulphate of alumina in the mechanical filters. The highest color observed in the effluents from sand filters was about 0.30. Colors of 0.15 are exceptional, and the average for the year ending August 31, 1898, was 0.07 for both sand filters. When it is considered that many Eastern cities have water sup- plies, generally considered satisfactory, having colors upon the same scale ranging from 0.50 to 1.00, it will be seen that these colors are quite slight, and will hardly be open to serious objection. Hardness. Both sand and mechanical filters have increased somewhat the hard- ness of the water during our experiments, but in different ways. The sand filters have increased the temporary, while the mechanical filters have increased the permanent hardness. In the mechanical filters the increase in hardness is due to the change of lime from carbonate to sul- phate, or from temporary to permanent hardness, the total hardness remaining unchanged. With the sand filters the permanent hard- ness has remained unchanged, while the temporary hardness has been increased by the solution of a certain amount of carbonate of lime contained in the sand. During the period covered by our experiments more than sixty per cent, of the lime originally present in the sand has been dissolved out, as is shown in the following table:- Approximate weight of sand in filter at Filter No. 1. Filter No. 2. commencement of experiments, pounds II5,6OO.OO 114,000.00 Quantity of lime in sand, per cent 1-32 i-35 Weight of lime in original sand, pounds. . Average amount of lime in sand, Sept., 1,525.00 i,539-oo 1898, per cent o-53 0-43 Lime removed, per cent, of original lime. . 60.00 68.00 Lime removed in pounds Approximate quantity of water filtered, 913.00 1,048.00 gallons ; 7,547,530.00 7,843,830.00 COMPARISON,-SAND AND MECHANICAL FILTRATION. 63 Average increase in hardness, parts per Filter No. 1. Filter No. 2. 100,000 Weight of lime in pounds, corresponding I.09 1.28 to this increase in quantity 685.OO 836.OO It is observed from the above that the lime will be exhausted before another year, and with its exhaustion the increase in hardness will be stopped. It was found after the experimental filters were filled that the sand used in them contained more lime than sands from certain places in the river. It would therefore probably be possible to select sand containing less lime than that which was actually used in the experimental filters. Boiler Tests. In order to put the filtered water to practical tests three 25 horse- power boilers were secured, as described in detail in the report of the Resident Engineer, and operated for some months, one being supplied with raw water, one with water from the mechanical filters, and one with water from the sand filters. It appears from the results, given in detail in the above mentioned report, that the boiler receiving the raw water produced much the largest quantity of scale, but that this scale was soft and readily removed. Both of the filtered waters produced a harder scale, although less in quantity. The water filtered through the mechan- ical filters produced somewhat more scale than the water from the sand filters and it also attacked the iron in places. The boilers were not operated during the periods of greatest muddiness, and consequently the boiler receiving the raw water probably compared more favor- ably with the boilers receiving the filtered waters than would have been the case at other seasons of the year. The average results of turbidity, color, bacteria, and hardness of the river water, mechanical filters, and Sand Filter No. i,for the seven months, ending August, 1898, but excluding results obtained during special ex- periments with mechanical filters, are as follows:- River Water. Mechanical Filters. Sand Filter No. 1. Turbidity . . . . 0.200 O.OO3 0.010 Color . . . . 0.26 O.O3 0.07 Bacteria ....ii,337 247 106 Total Hardness 3-3i 2-97 4-3i Temporary Hardness . . 2.56 1.66 3-53 Permanent Hardness, or En- crusting Constituents . 0.75 i-3i 0.78 REPORT OF CONSULTING ENGINEER. 64 It thus appears that the sand filter produced effluents with rather more than twice as much color and turbidity as the mechanical filters, while the mechanical filters produced effluents with more than twice as many bacteria as the sand filter. Temporary hardness was increased by the sand filter, but as shown above, there is reason for the belief that this increase will not be continued. With the mechanical filters the permanent hardness, or encrusting constituents, were increased 75 per cent., while no increase occurred with the sand filter. COST OF CONSTRUCTION OF FILTERS. The question of relative costs of filters upon the different systems is an important matter to be taken into consideration in deciding between them, and estimates have been made of the cost of constructing and operating sand and mechanical filters. The present consumption of water in Pittsburgh is fifty million gallons daily. On some days the consumption is much greater than the average for the year. It is nec- essary to provide filters for the maximum rather than for the average consumption. In general, with a reservoir system like that at Pitts- burgh, it is safe to provide filter units having a nominal capacity fifty per cent, above the annual average consumption, or for Pittsburgh seventy- five million gallons daily. The twenty-five millions capacity between the aggregate nominal capacity of the filters and the average annual consumption is sufficient to allow the highest daily consumption to be supplied with ease, and to serve as a reserve for cleaning, renewals, and repairs. In the estimates in each case sufficient land has been included to allow the plant to be doubled, and estimates for some of the structures not capable of being readily enlarged are sufficient for a large increased con- sumption. The remaining items are of such nature that their cost would be nearly proportional to the quantity of water to be provided. For our present purpose, then, it may be taken as sufficiently exact to assume that the cost of constructing filter plants will be directly proportional to the ca- pacities of the same, and the estimates given can be used for larger or smaller plants, by the application of appropriate factors. The estimates are as follows:- COST OF CONSTRUCTION. 65 Estimates of Cost of Construction of Filter Plants, Intake, Pumping Machin- ery, and Pump House. Sedimentation Basin . .. Sand Filters with Sedimentation Basins. 315,000 200,000 Sand Filters with Storage Reservoir. $ 455,ooo Mechanical Filters, North of River. $ 315,000 Mechanical Filters. South of River. $ Raw Wafer Reservoir. . 442,000 751,000 Filters 751,000 Filter House, Boilers, Pumps, Electric Tap-hts. etc 600,000 258,800 133,000 57,500 60,000 142,430 660,000 400,000 Pure Water Reservoir. . 133,000 78,600 60,000 I53,76O 133,000 210,300 60,000 205,130 Force Main and Conduits Tunnel Under River. .. . 467,200 Engineering and Contin- gencies, 10 per cent. .. 152,720 Total Cost of Construc- tion $ Land, with reserve area to double plant 1,691,360 420,000 $2,256,430 312,500 $1,566,730 75,ooo $1,679,920 50,000 Total Estimated Cost. . .$2,111,360 $2,568,930 $1,641,730 $1,729,920 The estimates for sand filters are for open filters with an effective filtering area of twenty-five acres. The additional cost of covering with a masonry vaulting would be $375,000. The estimates for mechanical filters apply equally to the Warren and Jewell Systems. While our tests were in progress the New York Filter Manufacturing Company acquired the patents covering both systems, and the prices are now uniform. It is probable that should mechanical filters be adopted for Pittsburgh, it would be desirable to use a type of filter differing somewhat from either the Warren or the Jewell Filters, as used in our experimental tests. It is not believed, however, that any required changes in design will affect materially the cost of the filters. The pumping station in connection with the sand filters and storage reservoir will operate against a greater head than the other pumping stations, and its cost is therefore greater. With mechanical filters on the south side of the river two independent plants are required, each supplying a separate part of the city; and because of uncertainties in the exact division of consumption in the two parts, the aggregate capacity of the filters is taken as ten per cent, greater than that of a plant at one point on the north side of the river. The cost of buildings, boilers, pumps, electric lights, etc., is also materially greater, because two sepa- rate plants are required instead of one, and because the sites are much less favorable to construction than that upon the north side of the river. 66 REPORT OF CONSULTING ENGINEER. No estimates have been made of the cost of constructing mechanical filters independent of the New York Filter Manufacturing Company, as this company controls certain patents. After the expiration of these patents it will be possible to construct mechanical filters independent of this company, and perhaps at a smaller cost than the prices now asked. Plans* are transmitted herewith, showing the locations of the various structures and the land areas included in the various estimates and their cost in detail; but as the exact location of filters can be varied if neces- sary, I would suggest that it should not be determined upon until after the necessary land has been acquired. As I am not familiar with the value of real estate in Pittsburgh, I shall rely upon you to correct my estimate for land should that be necessary. COST OF MAINTENANCE. Estimates have been made of the cost of maintenance of the filters upon the various systems as follows :- Sand Filters with Sand Filters with Mechanical Filters, Mechanical Filters, Sedimentation Storage North of South of Basins. Reservoir. River. River. Interest . .$ 68,619 $ 83,490 $ 53,356 $ 56,222 Depreciation . . 28,885 39,277 43,573 40,461 Pumping Costs • • 32,579 40,100 33,533 18,793 Operation of Filters, ex- - 36,500 elusive of Coagulant . . 62,101 45,625 32,120 Coagulant, I grain Sulphate of Alumina of 34,225 Total Cost per Annum . .$192,184 $208,492 $196,807 $186,201 Cost per Million Gallons 10.53 II.42 10.78 10.20 Interest has been taken on the entire estimated costs of the plants at 3I per cent. Depreciation has been reckoned as follows:-No de- preciation has been allowed upon land. On the intake, pumps, boilers, and mechanical filters an annual charge of 3.722 per cent, is made, which sum, placed at three per cent, compound interest, is sufficient to produce a fund equal to the original cost in twenty years. On the buildings and all masonry and other more permanent structures an annual charge of 1.326 per cent, is made, which charge is sufficient, computed as above, to produce a fund equal to the original cost in forty years. In computing the depreciation the proportionate charges for engineering and contingen- cies have been allowed. Some of the masonry structures included in the forty-year class would be entirely permanent in character, and there would be no depre- ciation upon them. It is thought best, however, to make the charges * See Plate No. 9, opposite Page 66. Plate No. 9. Mechanical Fitters north of river. Not recommended. drea of reservoir 84 acres. Land to be taken 800 acres. Sand Filters with Sedimentation Bas/m Recommended. Note. Thisp/an shows the arrangement upon which The estimate of cos/ is based. /t does not show /he exact form and iocat/on of structures which can oo/y be determined after de tai ted surveys have been made and in connection with The preparation of fu/i p/ans for the werh Mechanical Filters south of river. Sketch not drawn to scale. Not recommended. CITY OF PITTSBURGH FILTRATION COMMISSION LOCATION OF FILTERS AND LAND INCLUDED IN ESTIMATES OF COST Office of RUen Razer Dec. /893- Sand Filters with Reservoir. Not recommended. COST OF MAINTENANCE. 67 upon all structures, on the ground that with increasing population upon the water-shed, it is not certain that the Allegheny River water, even with filtration, will be a suitable source of supply for Pittsburgh at the point now selected for a longer period than forty years, and it is therefore advisable to provide for the payment of all indebtedness incurred on account of this plant within that period of time. With the mechanical filters, pumps, and other machinery, on which depreciation is reckoned sufficient to replace them in twenty years, cer- tain parts will undoubtedly be in good order and capable of service much longer than that period. Other parts of the machinery will require to be replaced at much earlier dates. On the whole, it is believed that a twenty-year life is a conservative estimate for the pumps and filters. In the case of mechanical filters there is a reason for limiting the estimated life of the plant not existing in the case of the pumps, namely, the probable change in the types of filters, and consequent antiquation of the plant. In the past the change in the types of mechanical filters has been very rapid. At the present time no plant is in existence which has been used for five years which would be considered as reasonably satisfactory. The type of filter has, however, been much improved, and it would not be fair to assume that changes will take place as rapidly in the future as they have done in the past, and that the plant now constructed would be incapable of future economical use in five years. On the other hand, it is not safe to assume that the plant now installed will continue to be reasonably satisfactory for a very long period of years; and aside from the question of rusting, wearing, and breaking of parts, it is not believed that it is prudent to take the life of these filters at more than twenty years. Pumping costs and operating expenses are reckoned on an average daily consumption of fifty million gallons per day. The pumping costs include in the first three estimates the costs of lifting water from the river to the filters, and in the fourth estimate includes the cost of pumping for the additional height and the cost of pumping the additional quan- tity of water required for washing filters. The operation of .filters, exclusive if coagulant, includes additional cost of pumping wash water, labor, fuel, new sand, repairs, superintendence, and all costs connected therewith. The cost of sulphate of alumina is taken at $25.00 per ton, or two dollars less than the current market price, as I am assured that with the quantity which would be required it would be possible to secure it at this price. The amount assumed, one grain per gallon, is somewhat less than was used in our experiments, and is as small an amount as it is believed that it will be possible to use to secure an effluent that would be reasonably satisfactory. Should a larger quantity of sulphate of 68 REPORT OF CONSULTING ENGINEER. alumina be employed to bring the bacterial efficiency up nearer to that secured by sand filtration, the cost would be increased at the rate of $0,187 per million gallons for each tenth of a grain per gallon. FINAL COMPARISONS, SAND AND MECHANICAL FILTERS. The comparison between sand and mechanical filters stands briefly thus:-With an amount of sulphate of alumina which makes the costs of the two processes substantially equal, the mechanical filters yield effluents containing from two to three times as many bacteria as the sand filters, and are consequently two or three times as likely to transmit disease germs, while, on the other hand, the effluents are clearer and more nearly colorless. In the adaptability of the filtered water to mechanical purposes the differences between the two will not be very great, but such differences as there are will be in favor of sand filters. If the raw water were very much more muddy than it is and contained less sewage, the advantage would be on the side of the mechanical filters, or at least the use of coagulant would be necessary. If, on the other hand, the water were less muddy and contained more sewage and sewage bacteria, the advantage would be decidedly with sand filters. Considering the fact that mud is not likely to increase, while the amount of sewage entering the river is sure to increase, and at a rapid rate, I believe that sand filters will be more satisfactory to the city than mechanical filters. NECESSITY OF A STORAGE RESERVOIR FOR RAW WATER. Nearly all of the difficulties in treating the Allegheny River water come at flood periods. It is only at these times that sand filters refuse to give practically clear effluents, and it is at these times also that mechan- ical filters require more sulphate of alumina for coagulation than can be neutralized by the lime in the water, and consequently the water passes with inadequate purification. The periods of excessive turbidity at Pittsburgh are of short duration. The worst water rarely lasts over twenty-four hours, and in no case, over three or four days. Moderately turbid waters sometimes continue for a week or more, but not of such a degree as to give serious trouble in their purification. The difficulties with very turbid waters would be entirely eliminated by the construction of a reservoir large enough to hold a ten days' supply of water, and estimates for such a reservoir have been made in connection with sand filtration. The reasons for constructing such a reservoir are almost equally urgent with mechanical filtration, and the cost of a mechanical filtration plant in place of the sand filters in con- nection with such a reservoir would not differ materially from that of the plant covered by the second estimate. With raw water as clear as that which this reservoir would assure at all times, the advantages OTHER METHODS OF FILTRATION. 69 would all lie with sand filtration and it has therefore not been necessary to take up in further detail mechanical filtration in connection with this reservoir. The reservoir site is a run on the north side of the river, conveniently situated with reference to the proposed location of other parts of the work. The natural drainage area tributary to this site is about five square miles, and the natural run-off from this area would flow into the reservoir, reducing slightly the amount to be pumped from the river. The population upon the water-shed is entirely rural, and is roughly estimated at sixty per square mile. The water secured from it would be fully equal in quality to that from the Allegheny River. In rainy weather the inflow into the basin from its own water-shed would be the largest, and the water received in this way would be quite turbid. The reservoir is so large, however, that it is believed this turbid water would not reach the outlet until it had been so long detained in the reservoir as to have deposited most of its sediment, and the water could thus be drawn from the reservoir to the filters at all times nearly free from suspended matters. In the same way, if it should be necessary to pump somewhat muddy water from the river to the reser- voir, a very thorough sedimentation would take place before the water passed from the reservoir to the filters. The construction of this reservoir would add materially to the cost of filtration, and its chief advantage would consist in that it would be possible at all times to supply perfectly clear water. We have demon- strated, however, from our experimental plant, that with sedimentation not exceeding twenty-four hours, it is possible to secure effluents at all times with only slight turbidities; and it is a question whether the re- moval of the last trace of turbidity is worth the additional cost of nearly half a million dollars which this reservoir represents. It would seem for the present to be the wiser policy to construct filters with only a sedimentation basin capacity equal to the average daily consumption ; and if at some future time it is found that the remaining turbidity in the effluents justifies the additional expense, the reservoir can be added, and the space occupied by the sedimentation basins can then be utilized for extending the filters to meet the increased consumption. Sedimentation basins have been built over into filters repeatedly in European filtration plants, and it is often possible to utilize them in this way to very good advantage. OTHER METHODS OF FILTRATION CONSIDERED. Several other methods of filtration have received our attention. One of these, namely, the Worms Tile System, was examined experimentally at some length. This system is covered by certain patents, and the 70 REPORT OF CONSULTING ENGINEER. owners of these patents have informed us that the cost of tiles would be twenty dollars each. To supply the quantity of water required by our estimates at the rates of filtration found possible in the experimental trials, the cost of tiles alone would exceed $1,000,000. When this amount is added to the cost of setting up and connecting the tiles, and the cost of necessary appurtenances and land intake, pumping station, pure water reservoir, etc., it is apparent that the cost of the plant will not be less than two and one-half million dollars, and may reach three million dollars. There is reason to think that the operating expenses would be greater than the operating expenses of either sand or mechanical filters; and as the experiments did not give assurance that the requisite quantity of pure water could be secured under all conditions, this process has not been considered further. Several other processes have been called'to our attention which in- volve the use of more or less peculiarly constructed sand filters, at rates of filtration several times as great as are commonly used for sand filters. Without raising the question of the adaptability of these systems to other conditions, it is certain that no system of sand filtration without coagu- lant will effectively clarify the Allegheny River water at rates more than several times as great as those which were used during our experi- ments. The use of asbestos applied to the surface of sand filters has also been suggested. This process is covered by a patent, and if used would hardly increase the yield or efficiency of sand filters. It might reduce the operating expenses, and if so could be adopted and used at any time upon sand filters as ordinarily built, no special construction being neces- sary with The question of the use of other coagulants than sulphate of alumina has not been considered by us. The report of Mr. Fuller upon the experiments at Louisville treats this matter quite fully; and there is no reason to suppose that any other coagulant could be substituted to advantage for the sulphate of alumina used in our experiments, and which serves as a basis of our estimates. The use of natural filtration by galleries built in the bed of the Alle- gheny River has been suggested to us, with various modifications. A number of water supplies are now being drawn from the river in this way in the neighborhood of Pittsburgh, and these supplies have been investigated, as described in detail in the report of the Resident Engineer. It may be said in regard to them that the water thus secured is always harder than that secured by ordinary sand filtration, owing to the fact that the water is much longer in the sand, and comes in contact with a larger body of it. The difficulty of securing an adequate supply of water also increases much more rapidly than the required water quan- AUXILIARY SUPPLY OF UNFILTERED WATER. 71 tity. A million gallons per day is secured with comparative ease, but with two or three million gallons, the difficulties are very much increased, and with very large supplies they become almost insurmountable. The reason for this is that the amount of water which can be drawn from any stretch of river is limited, and that a very small crib serves to take the quantity of water which can be drawn from a certain area of river bottom. When the crib is enlarged, or other cribs are built in the neighborhood, they interfere with each other, drawing from the same area, with the result that the supply is not increased in proportion to the size of the cribs; and in order to secure a very large supply, it is necessary to construct structures extending over such a large extent of river bottom as to make their expenses absolutely prohibitive. The use of domestic filters in each house in the city, to filter drinking water only, has been suggested. If the whole supply should be so filtered, the expenditure would be many times greater than that of a municipal plant. With only the drinking water filtered, it is not clear that the ultimate cost would be less than with one large plant, and the city would still suffer from many of the disadvantages of the present supply. auxiliary supply of unfiltered water for manufacturing purposes. It has been suggested that the excessive consumption of water in Pittsburgh is due to the enormous quantity of water required for manu- facturing purposes, and that it would be possible to build an auxiliary system for supplying unfiltered river water to these establishments, thereby reducing very much the quantity of water to be filtered. As a matter of fact, the manufacturing establishments do not use as much water as is commonly supposed, or at least they do not draw such quantities from the city mains. Nearly all of the establishments requiring water in large quantities, for purposes for which the river water in its raw state is suitable, have their own pumping plants, and are able to pump water for their own use much cheaper than it can be supplied from the present city works, or from works especially con- structed for that purpose. The reason for this is that while the pump- ing of water in relatively small quantities in various places is more ex- pensive than pumping a large quantity at a central point, there are several important advantages in the arrangement. Each manufacturer pumps only against the head which he requires, and thereby saves all the friction in pipes and additional head to which a central plant would require to pump, because it would have to meet the highest pressure required by any one and not the average pressure; and further, the entire cost of the distribution system is saved, and this forms a large part of the cost of a central plant. The estimated cost of an auxiliary pumping station for unfiltered 72 'REPORT OP CONSULTING ENGINEER. water, with intake and distribution system along the river fronts in that part of the city now supplied by the city works, is $565,000. If the system should be extended to supply also the south side of the Monongahela River, the cost is estimated at $660,000. This system would have a maximum capacity of twenty - five million gallons per day, and would be suitable for the supply of an average daily con- sumption of one-half this amount, or one-fourth of the quantity, of water now supplied from the Brilliant pumping station. The size of filters to be constructed at Brilliant, in case this amount of water should be diverted from the regular to the auxiliary supply, could be reduced one-fourth. The saving in the cost of filters would be, in round numbers, $400,000, and the saving in the cost of operation, including preliminary pumping, but exclusive of interest and deprecia- tion, would be about $20,000 per annum. The cost of operating the auxiliary system may be taken as equivalent to the cost of pumping an equivalent quantity at Brilliant. The use of an auxiliary system under the conditions assumed above would thus result, in round numbers, in an increased outlay of $165,000, and a reduction in operating expenses of $20,000 per annum. It would also make necessary certain changes in the distribution system of the water works, the importance of which cannot now be accurately estimated. The total saving would be comparatively small. The above computation is based upon the assumption that one-fourth of the supply could be diverted to the auxiliary system. Let us consider now what the facts are in this respect. The quantities of water supplied to manufacturing and business establishments, as measured by meters and as estimated by the water assessors for the last fiscal year, amounted to an average of 3,700,000 gallons per day. A part of this quantity was used for purposes for which the raw river water would not be suitable. It should be remembered in this connection that an auxiliary pumping system would be located further down the river than the Brilliant Station, and the waters from it would be polluted by sewage from one of the city sewers, and would be far more objectionable hygienically than the present supply. Further, it would carry at least four times as much sediment as the present supply, as the water would be pumped into the pipes direct, without the removal of any sediment, while at least three-fourths of the sediment is now removed in the Highland Park Reservoir. Many establishments included in the above list use water for purposes for which raw water of this quality would be utterly unsuitable, and I estimate that at least one-half of the quantity could not be diverted. There remain 1,850.000 gallons per day which could apparently be di- verted to an auxiliary supply. Even if we add to this a liberal allowance AMOUNT OF WATER AND RESTRICTION OF WASTE. 73 for the slip of meters and double the amounts estimated by the water assessors, we have only three million gallons per day which could be diverted, or one-fourth of the amount contemplated in the above estimate. This quantity is so small that a station supplying it would cost more, both in construction and in operation, than the saving to be effected in the cost of filtration by its diversion. It appears then that unless there is a demand for water of this quality far in excess of anything which now appears, it will be utterly impracticable to effect a saving to the department by the introduction of an auxiliary water supply. There is a further important objection to an auxiliary pumping station, namely, that the employees in shops where such water is used are sure to drink it at times. The sanitary objections to such supplies are shown in the report of Prof. Sedgwick. AMOUNT OF WATER TO BE PROVIDED AND THE RESTRICTION OF WASTE. The quantity of water used in Pittsburgh is increasing very rapidly, as is shown by the following table, showing the populations supplied by water, and the average daily quantity of water pumped each year:- Year. Estimated Population in Wards 1 to 23 Ine. Average Daily Quan- tity of Water Pumped. Gallons Per Inhabitant. 1883 129,000 20,300,000 157 1884 135,000 22.700,000 168 1885 T4 1 ,OOO 23,700,000 168 1886 147,000 25,800,000 176 1887 153,000 29,100,000 I90 1888 159,000 29,500,000 186 1889 165,000 33,900,000 205 1890 171,000 36,700,000 215 1891 176,000 38,800,000 220 1892 l8l,OOO 40,500,000 224 1893 187,000 38,900,000 20(8 1894 193,000 39,300,000 203 1895 199,000 41,900,000 210 1896 205,000 45,200,000 220 1897 211 ,OOO 49,200,000 233 1898 2l8,OOO 1899 226,000 1900 234,000 The quantity of water pumped has doubled in the last twelve years, and the quantity supplied per inhabitant has increased forty per cent. An estimate has been made of the population which may be expected in the district now supplied from the city water works, in the present city limits, and within a ten-mile radius of the City Hall. These estimates are as follows:- 74 REPORT OF CONSULTING ENGINEER. Year. In District now .Supplied by City Water Works In Present City Limits. Within a Ten-Mile Radius from City Hall. J 890 171,000 243,000 503,000 IQOO 234,000 320,000 700,000 1910 320,000 420,000 980,000 J 920 440,000 560,000 1,370,000 1930 600,000 740,000 1,920,000 If the consumption of water should keep pace with the increasing population and increase faster than the population, as it has been doing in recent years, a filter plant would require to be provided of enormous dimensions and prohibitive cost. Fortunately this is not the case. The experience of Pittsburgh is not different from that of other American cities which have supplied water at fixed rates and without limiting in any way the amount of water used and wasted by consumers. Under these conditions the volume of water pumped always increases faster than the population, and is only limited by the fact that after a time the cost of securing and distributing the water becomes so great as to make rational measures imperative. Natural gas was formerly sold in Pittsburgh at a fixture rate, the amount charged for heating a house depending upon its size, etc. The practice has, however, been given up, and all gas is now sold by meter. The temptations to abuse the privilege of using water supplied at a fixture rate are quite as great as they are in the case of gas. In fact the oppor- tunities are better, because gas cannot be discharged unburned into a house without making it uninhabitable, and if an excessive quantity of gas is burned, the house becomes too warm for comfort. There is thus a certain physical limit upon the amount of gas which can be used in a house. With water, however, this is not so. Faucets can be left open and leaks allowed to remain unrepaired, and the water allowed to flow to the sewers in absolutely unlimited quantities without benefiting any one. It has been found by careful and extended observation in both American and European cities that in the best class of modern houses an abundant supply of water for domestic purposes does not exceed from twenty to forty gallons per capita daily. Only in the very largest places, where many servants are kept, and much water is used for lawn sprink- ling, do the quantities become as high as fifty or sixty gallons per capita daily. As an average for American conditions, thirty gallons may be taken as a liberal allowance for all the water which can be used. The popula- tion now supplied with water from the Pittsburgh works is about 220,000. The quantity of water required to supply the needs of this popu- lation at thirty gallons per capita daily is 6,600,000 gallons. There were in manufacturing and business establishments, where meters were in RESTRICTION OF WASTE. 75 use during the last fiscal year, 692,000,000 gallons, and in other such establishments it was estimated by the assessors that 654,000,000 gallons were used. Assuming that the meters registered only two-thirds of the water in places where they are used, and that the assessors estimated only one-half of the water used in the remaining places, the water used in all manufacturing and business establishments was 6,400,000 gallons daily. The amount of water used in schools, hospitals, public buildings, public fountains, for street sprinkling, etc., is rarely more than five gallons per capita daily. On this basis 1,100,000 gallons would be required daily for public purposes. Assuming further that there were unavoidable wastes of various kinds from the water works equal to the public uses, or 1,100,000 gallons, we have 15,200,000 gallons daily, or about sixty-nine gallons per capita as the amount of water legitimately used in the city of Pittsburgh. The amount pumped is more than three times this quantity, and it is a fair statement that two-thirds of the water now pumped is wasted without benefit to any one. Various ways have been suggested for preventing the waste of water. One of these ways has been very much more successful than any other. This is the method which has been universally adopted for the sale of gas, namely, the use of meters. Under this system the water supplied to each consumer is measured and payment demanded according to the amount used. There is often a prejudice against the use of meters, which arises from the thought that people will be limited in the use of water, and cannot use as much as they desire without making excessive payments for it. There is also the feeling that if the consumption of water in the city should be reduced to one-half or one-fourth of the present consump- tion, each person would have to get along with one-half or one-fourth as much water as is now used. As a matter of fact, this idea does not present even remotely the truth. A majority of people are reasonably careful in the use of water and do not waste excessive amounts. A majority of families in Pittsburgh probably use at the present time less than the amount of water mentioned in the above estimate. It is the minority of people, who, by carelessness or willful waste, discharge water into the sewers in large quantities, and increase enormously the amount of water which must be provided, and consequently the cost of water to all the people. At the present time the loss inflicted by the careless or wasteful people is borne by the whole city. If a meter is put on every service, the people who waste water will have to pay for it, and others will be relieved from the burden, and the cost of water to them will be materially reduced. The cost to the people who are now wasting water will also be 76 REPORT OF CONSULTING ENGINEER. reduced, if they are willing to learn by experience, as nearly all of them will, that they cannot waste water without paying for it. The cost of installing a meter system is considerable, but it is very much less than the cost of installing the pumps, filters, reservoirs, and larger mains that will be necessary in case unrestricted waste is allowed to continue. The meter system also results in a saving in water rates to all people except those who under previous conditions are fraudulently or through carelessness securing quantities of water largely in excess of those to which they are entitled. I therefore most earnestly recommend that the city of Pittsburgh adopt forthwith the meter system, and I would make the following suggestions in regard to it:- (i) That the city should own and set all meters, and assume all care of them. (2) That the Superintendent should have the right to meter any service at his discretion. (3) That all services should be metered commencing with the largest and those where unusual use or waste is thought likely to exist. (4) That wherever a service is metered all water shall be paid for at meter rates, excepting that the sum charged shall not be less than three-fourths of the present fixture rates, and this sum shall be collected in all cases where less than a corresponding amount of water is used. (5) That all schools, hospitals, and public institutions now supplied with water free or at a nominal charge, shall be metered; that the amount of water actually required by each shall be estimated by the Superin- tendent, and notice thereof sent to the respective institutions; and that in case water is drawn by any of them in excess of the amount thus allowed, the excess shall be paid for at the regular meter rates. In case of another city department, the excess shall be paid out of the appropria- tions of that department. After the system has been so far introduced that the revenue derived from the sale of water is assured, the minimum rate should be reduced to one-half the fixture rate, or to such other amount as the financial condi- tion of the water works will justify, and when all services are metered and the fixture rate is abolished, the minimum rate should be determined by a simpler schedule than the present fixture rate. This arrangement will allow all parties taking water at fixture rates to save one-fourth of their present bills, and at the same time will assure the department an ample revenue to meet its present expenses, and the ex- penses of a filter plant when it is installed. Cities Which Have Adopted the Meter System. The meter system has been adopted and applied to all consumers by a number of European cities, notably by Berlin, and by a few American METEK SYSTEM. 77 cities, namely, Atlanta, Yonkers, and Madison. It has been adopted and applied to all services except the smaller domestic services by a much larger number of American cities,-Milwaukee, Providence, Syracuse, Worcester, Fall River, Hoboken, Lawrence, Manchester, Utica, Brock- ton, and Pawtucket have adopted in this way, and having more than half of their services metered. In addition to the above; New York, San Francisco, Kansas City, Lowell, Nashville, Toledo, Dayton, Des Moines, Peoria, Springfield, Quincy, Bay City, and Taunton have metered more than a quarter of their services, and nearly all cities which have started upon the introduction of the meter system are extending its use as circumstances permit.. Equitable Basis for Meter Rates. The amount of money now obtained from the sale of water is about $740,000 per annum. This is on the basis of about fifty million gallons per day. With filters installed of this capacity, the operating expenses, interest and depreciation charges will amount to about $190,000 per annum. The cost of maintaining a meter system will not exceed $40,000. The amount of money now raised by the water works is in excess of the operating expenses and interest and sinking fund charges for the water works. The balance is transferred to other city departments. Assuming that the works are to be maintained on a basis as profitable to the city as at present, the amount of revenue to be raised after tl^ filter plant and meter system are installed, and with the quantity of water pumped as at present, is $970,000 per annum, or less than 5| cents for every thousand gallons of water pumped. It is found, however, that it is impossible to operate a water works system so that all of the water will be accounted for. In the best German practice, with all the services metered, sometimes as much as 90 per cent, of all the water pumped is accounted for. This, however, is rare, and has never been reached in American practice. Sixty per cent, is a good American average, and on this basis the average meter rate should be about nine cents per thousand gallons. With very large consumers the rate should be somewhat less than for small consumers, and eight cents, or the present minimum rate, may be taken in these cases as not far from right, while the domestic rate must be maintained considerably higher on account of the greater slip in the small meters and waste and leakage from service pipes. This basis, however, would not be a safe basis to assume in adopt- ing the meter system. As I have shown, the greater part of the water pumped at the present time is wasted. With the meter system installed the consumption will be very much reduced, and consequently the revenue. A large part of the operating expenses, namely, the cost of 78 REPORT OF CONSULTING ENGINEER. filtering and pumping, are nearly proportional to the quantity of water pumped, and will be reduced. The general administrative expense will not be reduced by reducing the consumption. If the consumption should be reduced one-third at once, it is esti- mated that the operating expenses, including the operating expenses of filters, would be reduced by $120,000, leaving $850,000 to be derived from the sale of twelve billion gallons of water, or seven cents pet thousand gallons. Assuming that the meters can be depended upon to register sixty per cent, of the water pumped, the meter rate upon this basis should average twelve cents per thousand gallons, and should be somewhat less for large consumers and somewhat more for domestic purposes. Changing radically the system of charging for water invariably results in some uncertainty as to the amount of revenue to be derived from the new schedule, and to prevent the possibility of a deficit which might embarass the administration, I beg to suggest a rate of sixteen cents per thousand gallons for domestic purposes, and gradually re- ducing with increased quantities to the present minimum rate of eight cents per thousand gallons for the largest takers. In order to protect the city against serious reduction in revenue, in case the consumption should fall off more than is anticipated, the minimum rates are fixed at three-fourths of the present fixture rates, which will assure the city of a large revenue in any event, and will, at the same time, allow the takers to secure a twenty-five per cent, reduction in their present rates. It is necessary to allow them to save something, otherwise the objection to the change will bewery great. Cost of Installing Meter System. There is a difficulty in estimating the cost of installing meters in Pittsburgh, on account of the very inadequate information regarding service pipes. People supplied with water from the city works are taxed according to the sizes of their houses, number of fixtures, etc., without regard to the manner in which they are connected with the city pipes. It will be necessary to have the service pipes straightened out in detail, and to know just what connections there are with the city pipes, and who is attached to each connection. In the absence of definite infor- mation regarding service pipes, only a rough estimate of the cost of meters can be made. Judging from the experience of other cities, and from such information regarding service pipes in Pittsburgh as can be obtained, the cost of installing meters on every service will be about $600,000. In connection with the installation of meters, the service pipes should be given a thorough overhauling, and this may increase the expense SUPPLY OF THE SOUTH SIDE WITH FILTERED WATER. 79 somewhat above the figure mentioned. This work should be done, however, whatever the cost, as the present system, or lack of system, in attending to the distribution of water cannot fail to result in great loose- ness in the use of water, and in heavy losses to the city, which losses, I believe, are far greater than the cost of putting the system in satisfactory condition. It will, of course, be impossible to do this work all at once. I would recommend that the work be begun at once, with an appropriation of $100,000 for the first year, and carried on as rapidly as circumstances will permit, the whole to extend over a period of perhaps five years. The saving effected in preventing waste of water and in securing the collection of revenue for water net now paid for, will fully pay for con- tinuing the work, and no further appropriations on this account need be made. With meters installed as recommended the consumption will stop increasing and will gradually diminish. A filter plant suitable for the present consumption will be sufficient to supply water to the population resident within the present water limits for a period of at least twenty- five years, or will be sufficient to supply water to the whole population of the city, including those wards now supplied by water companies, for at least fifteen years. Should the present unrestricted use of water be allowed to continue, a filter plant as proposed will have been outgrown almost before it is completed, and additions will require to follow each other on a scale and with the frequency which can hardly be estimated. SUPPLY OF THE SOUTH SIDE WITH FILTERED WATER. That part of the city of Pittsburgh south of the Monongahela River, and having an estimated population of about 78,000, is supplied with water by the Monongahela Water Company. As has been stated above, the Allegheny is in every respect a more desirable source of supply than the Monongahela River, and, from an engineering standpoint, it would be better to supply this part of the city with water from the Allegheny than to attempt to filter the water of the Monongahela River. The filters included in the above estimates are of sufficient capacity to supply the whole of the city, including the South Side, in case the meter system is introduced. In case the meter system should not be introduced, the quantity of water required would be much greater, and to meet the present consumption of the whole city a filter plant would be required costing about $2,600,000; and to meet the estimated consumption in 1910 without meters, namely, 116,000,000 gallons, a plant would be required costing over four million dollars. I have not considered this question further, as arrangements for it, either by the city direct or through the Monongahela Water Company, involve questions not of an engineering nature. 80 REPORT OF CONSULTING ENGINEER. GRAVITY SOURCES. The country about Pittsburgh is rolling, with a general slope down- ward toward the west, and there is no land in the immediate neighbor- hood of the city high enough to yield a gravity supply of water. There are valleys in the Allegheny mountains east and south of the city high enough so that water from them could be taken by gravity to Pittsburgh. The nearest water-sheds of this kind are those of certain tributaries of the Youghiogheny and Kiskiminetis Rivers among the foot hills of the mountains. Of these the most promising one which we have found is the water-shed of Indian Creek. Indian Creek enters the Youghio- gheny River eight miles beyond Connellsville. Laurel Hill Creek, im- mediately beyond Indian Creek, has a smaller water-shed and is farther from Pitsburgh. The Loyalhanna above Ligonier, the next water-shed to the north of Indian Creek, has not a sufficient drainage area above the town, where only it could be taken. Farther away, beyond Laurel Ridge, the Conemaugh River at Johns- town has a sufficient drainage area and a sufficient elevation. Its valley is occupied by the Pennsylvania Railroad, which would make the construction of an adequate reservoir difficult, if not impossible. Stony Creek, south of Johnstown, is also sufficient in size and elevation, but its valley is occupied by the Baltimore & Ohio Railroad. The distances from Pittsburgh are also greater than the distance from Indian Creek. South of Indian Creek and Laurel Hill Creek are the Castleman, the Youghiogheny and the Cheat Rivers. Any of these could be taken at points high enough to flow to Pittsburgh by gravity. It has been suggested that the water from one of these streams might be brought to Pittsburgh through a conduit. It is doubtful if the flows of any of them could be depended upon at all times to yield a sufficient quantity of water for Pittsburgh without storage reservoirs. With moderate sized storage reservoirs any of them would be ample. All these streams have rapid currents, and during heavy rains they become very muddy, although the turbidity disappears quickly afterward. If these waters should be brought to Pittsburgh without sedimentation, or with only such sedimentation as could be secured in a comparatively small res- ervoir through which the flood currents would have to be allowed to flow, the city would suffer in only less degree from mud than it now does. All projects of this nature have therefore been dismissed, and in case any of these streams should be utilized, it must be in connection with adequate storage reservoirs, and when so considered the cost would become much greater than that of a supply from a storage reservoir on Indian Creek. GRAVITY SOURCES. 81 Indian Creek. The Western Water Company had acquired certain property upon Indian Creek, and had made certain investigations in regard to its de- velopment for water supply purposes, and this information has been put at our disposal by officers of the Company. In case the city should decide to secure its water in this way,' it would have to acquire the property of the Western Water Company, together with such other real estate as might be necessary. Preliminary examination indicated that many of the conditions were favorable for securing a water supply from this source. The services of Mr. Emil Kuichling, Chief Engineer of the Rochester Water Works, and an engineer of large experience in water works construction, were secured to investigate more in detail the possible development of this supply, and he has made a report thereon with estimates of cost, which I transmit to you herewith. You will find in it a description of the project, and estimates in greater detail. Chief Features of the Project. This project involves the construction of a conduit line, from the reservoir to Pittsburgh, a distance of forty-seven miles, forty-two miles being steel pipe, and five miles tunnel. The dam required would be higher than any dam yet constructed. The water in the new reservoir would be 238 feet above the present stream, and the total height of masonry would be 270 feet. The highest dam yet constructed or undertaken is the new Cornell dam for the water works of the city of New York, in which the water line of the finished reservoir will be 149 feet above the original water level, and the extreme height of masonry will be about 290 feet. The general height will*be considerably less. The Indian Creek reservoir would have an area of 2,000 acres, and a capacity of forty billion gallons. Quantity of Water. The quantity of water which can be developed from the Indian Creek water-shed is estimated at ninety-two million gallons daily. By adding Laurel Creek the supply could be increased to an amount which is estimated at one hundred and thirty million gallons daily. The flow of Indian Creek in summer is much less than the amount above estimated. The project involves the construction of a dam large enough to hold a year's supply of water when the city is using seventy- five million gallons daily, and the heavy winter and spring flows would be stored and made available during those months of the year when the flow of the stream is less. The dam is also large enough to hold some of the water of wet years and allow it to be drawn in dry years. 82 REPORT OF CONSULTING ENGINEER. Quality of Water. The water would be very soft; softer than the Allegheny River water. It would be nearly colorless. Under some conditions it would be subject to disagreeable tastes and odors, although it is hardly probable that these conditions would be of frequent occurrence or would become generally offensive. As there is but comparatively little population upon the water-shed, and that of such a nature as to admit of ready control, and owing to the purifying actions which take place in very large reservoirs, the water would compare favorably with the best water supplies of the country in quality, and in its natural state would be equivalent in purity to the Allegheny River water after filtration. Difficulties with Coal Lands. The pipe lines from the reservoir to the city would pass over many miles of coal fields. As the coal is removed settlements occur, and there would be danger that the pipes might be broken and the supply cut off. For this reason it is not considered safe to use a single line of pipe, but the estimate is for two independent lines, connected at selected points on solid ground, so that in case of a break in either line, all of the water could be sent through the other line until the break could be repaired. Cost of Work. The total cost of works for the introduction of water from Indian Creek is estimated at $13,568,500. This provides two lines of pipe capable of delivering together seventy - five million gallons per day. Owing to fluctuations in the daily consumption, it would not be safe to depend upon these pipes after the average consumption reached sixty-five million gallons, and at that time a third pipe would have to be added. When the average consumption reached ninety-two million gallons per day, additonal water sources would have to be added. Laurel Hill Creek is the most obvious source to be taken for this pur- pose, and estimates have been made of the cost of adding Laurel Hill Creek to the system, and of adding a fourth pipe line to the city. These last estimates are less accurate than those relating to Indian Creek, be- cause of less complete data regarding Laurel Hill Creek. COMPARISON OF THE COST OF A GRAVITY SUPPLY AND THE PRESENT SUPPLY FILTERED. I have prepared a diagram showing the annual charges for a gravity supply and for the present supply filtered, first, upon the supposition that the meter system will be adopted, and, second, upon the supposi- tion that it will not be adopted, and that the consumption will increase COMPARISON OF GRAVITY AND FILTERED SUPPLIES. 83 gradually to 300,000,000 gallons per day, which diagram is presented herewith.* The charges included in this diagram represent all costs of delivering the water into the distributing reservoirs. F01 the gravity supply these charges are made up as follows:- Interest is reckoned at 3.25 per cent, on the total expenditure. For the cost of the steel pipe lines, sinking fund payments are taken at 1.326 per cent, of the cost, sufficient with compound interest to replace the pipes at the original cost at the expiration of forty years. Sinking fund payments on all the rest of the expenditures are taken at 0.6133 per cent., sufficient to provide for the payment of bonds at the expiration of sixty years. To these sums are added maintenance expenses, amount- ing to $14,000 per annum. These charges amount to $582,500 per annum, with the original plant, which will suffice until the average consumption reaches sixty- five million gallons daily. They will then be increased with the third pipe line to $722,300 per annum, and will then remain constant until the consumption reaches ninety-two million gallons daily. With the addition of Laurel Hill Creek and a fourth pipe line, they will be in- creased to $978,000, and will then remain constant until the consumption reaches one hundred and thirty million gallons per day, after which new supplies will have to be found. In computing the amount of water required, it is assumed that the wards now supplied by private water companies will be supplied from the city works after 1905. The exact date is not of material importance in the estimates. The relative costs would not be materially changed if it should be taken a few years earlier or later. The costs of maintaining the present supply and of filtering it are computed as follows:-The total cost of maintenance of filters, includ- ing interest, depreciation, and operating expenses under the first scheme, page 66, are taken at $192,184 per annum. To this is added the cost of pumping the water from Brilliant to the distributing reservoirs. The present cost is $8.00 per million gallons, and when the new reservoir is completed it may be estimated that one-half of the water will be pumped to it at a cost of $6.00 per million gallons. The total cost of pumping will then average $7.00 per million gallons, or $127,750 per annum for fifty million gallons daily. To this must be added an allowance for the depreciation of the machinery at the Brilliant pumping station, which is estimated at $22,000 per annum, making a total annual cost of $342,000 for fifty million gallons of filtered water per day delivered m the reservoirs. No allowance is made for interest on the cost of the Brilliant pumping station, as the city now owns it, and no further capital outlay is required in connection with it as long as the consumption does * See Plate No. io, opposite Page 84. 84 REPORT OT CONSULTING ENGINEER. not exceed the amount mentioned. Renewals are provided for in the charge for depreciation. For consumption in excess of fifty million gallons per day the costs of construction and operation are taken as increasing in proportion to the quantity filtered, but with no addition for land and certain struc- tures provided in the original estimate, large enough to allow the plant to be doubled; and it is further assumed that additional pumping ma- chinery will be required at Brilliant, on which the interest as well as the depreciation is reckoned. The annual charges computed in this way amount to $342,000 for fifty million gallons daily and $6,700 per annum for each additional million gallons. No account has been taken of the fact that some of the bonds would be ultimately retired by the sinking fund charges, and interest thereby reduced. On the more perishable parts of the plants depreciation only has been reckoned, and it is assumed that this depreciation would replace the parts when necessary and that the indebtedness would remain the same. Should it be inexpedient to renew them for any reason, however, the accumulated depreciation charges would suffice to pay off the outstanding bonds. On the more permanent parts of the plant sink- ing fund charges have been taken sufficient to retire the indebtedness after forty years for the filtered supply and after sixty years for the gravity supply. No reduction in capital expense could then be expected within these periods. It is estimated that filters could be put in service two years earlier than the gravity supply, construction being commenced at the same time, and the charges are assumed as increasing from nothing to the full amount at a uniform rate during the period of construction, as plotted in the diagram. Comparison of Costs. Comparing the aggregate annual charges for the two systems with meters, we have:- Estimated Population Last Date. AVERAGE ANNUAL CHARGES. Excess of Cost of Grav- ity Supply ; Per Cent. Gravity Supply. Present Supply with Filtration. 1900 to 1910 . . 420,000 $460,000 $300,000 53 1910 to 1920. . . 560,000 582,000 347,000 68 1920 to 1930 . . 740,000 652,000 444,000 47 1930 to 1940 . . 920,000 768,000 562,000 37 1940 to 1950 . . 1,100,000 972,000 682,000 43 The aggregateTStimated charges for fifty years are thirty-four million dollars for the gravity supply, and twenty-three million for the present supply with filtration. The gravity supply will thus cost in that time forty-eight per cent, more than the present supply with filtration. P late No. 10. Annual charges without meters. CITY OF PITTSBURGH FILTRATION COMMISSION /ESTIMATED CON SUMPTION OF WATER WITH AND WITHOUT METERS AND COMPARISON OF ANNUAL CHARGES OF PRESENT SUPPLY FILTERED WITH A GRAVITY SUPPLY. Annual charges with meters. Average daily consumption. Millions of gallons. CONCLUSIONS AND RECOMMENDATIONS. 85 An important difference between the schemes is the way in which money is required. In the gravity scheme the,capital expenditure must be met practically all at one time whether the full amount of water is wanted or not. With filtration and pumping the capital expenditure required at first, although considerable, is only a sixth of that required for the gravity scheme, and the operating expenses are only incurred as water is required, and in proportion to the amount needed. With the gravity scheme it is obvious that the only admissible procedure is to construct a dam and tunnel capable of delivering the whole available supply of the water-shed at one operation. This entails a heavy burden for interest and sinking funds for a long period of years. With the filtration and pumping scheme, on the other hand, only so much money need be spent as will provide a supply for the immediate requirements of the city, and further expenditure need be made only as the growth of the city demands it. If the regulations regarding the sale of water suggested to you should be adopted, no extensions will be required for a long period of years, and the charges under the filtration scheme will be much less than under the gravity scheme. The Indian Creek scheme is certainly not to be carried out in a less complete manner than that contemplated in our estimates. It would never do to have to cut a second tunnel through the mountain, or to raise a dam of the magnitude of the one which must be built in any event, or to have the city left without water by a break in a single pipe line. To carry it out as estimated requires an expenditure of money at once which would load the city of Pittsburgh with a debt which the city ought not lightly to assume. On the other hand, the pumping and filtration scheme can be proceeded with at an expenditure so moderate that all charges can be readily met from the income of the department without embarrassing the city in any way. CONCLUSIONS AND RECOMMENDATIONS. I have shown that your present water supply is seriously objection- able, because of the mud which it carries, and because of the polluting matters which enter the river. By filtration the mud and the effects of pollution can be effectively removed. It is feasible to introduce a gravity supply of excellent water from practically unpolluted sources, but the cost of doing it will be six times as great as the cost of installing filters. The operating expenses of filters are greater, but allowing for them, the cost of the gravity supply is much greater than the cost of your present supply with filtration. I therefore recommend that the present supply should be continued in use, and that it should be filtered. 86 REPORT OF CONSULTING ENGINEER. Two methods of filtration have been examined, either of which is capable of furnishing at all times sufficient water free from mud or objectionable turbidity. Of these systems, one, namely, sand filtration, removes more completely the effects of pollution than does the other, namely, mechanical filtration. I therefore recommend the adoption of sand filtration. The city is now wasting several times as much water as it uses. The experience of other cities shows that the consumption can be greatly reduced by the adoption of the meter system for the sale of water, and the cost of filtration and pumping can be kept within reasonable limits. I recommend the adoption of the meter system. A filter plant suitable of supplying an annual average consumption of fifty million gallons per day, and with a maximum capacity one-half greater, will supply the whole city, including those wards not now supplied from the city works, until the population of the city reaches half a million. The general arrangement of such a plant has been indicated in connection with the estimates for the various filter projects. It would consist of a pumping station on the north side of the river, pumping water to sedimentation basins holding fifty million gallons, from which it would flow to open sand filters with an effective filtering area of twenty-five acres; thence to a covered pure water reservoir, and thence through a tunnel under the river to the Brilliant pumping station. The cost of constructing such a plant, with all accessories complete, is esti- mated at one million, six hundred and ninety-one thousand (1,691,000) dollars. To this must be added the cost of the necessary land, which is estimated at four hundred and twenty thousand ($420,000) dollars, and an appropriation of one hundred thousand ($100,000) dollars for commenc- ing the work of installing meters. The total estimated cost of carrying out the works now recom- mended is two million, two hundred and eleven thousand ($2,211,000) dollars. I believe that this is the best way for the city of Pittsburgh to supply itself with good, wholesome, and clear water, and I recommend its adoption, and that the necessary arrangements for carrying it into effect be adopted. Respectfully submitted, Allen Hazen. January 9, 1899. UPON A Gravity Water Supply FROM INDIAN CREEK. BY EMIL KUICHLING, C. E. EXHIBIT 3. Allen Hazen, Esq., C. E., Consulting Engineer, Pittsburgh Filtration Commission. Dear Sir :- In response to your request for a brief account of my investigations of the plan for supplying the city of Pittsburgh, Pa., with an adequate quantity of potable water by gravity from Indian Creek, I beg leave to submit the following general report:- Sottrcc. The source of the contemplated supply is Indian Creek, which flows into the Youghiogheny River at a point about 42 miles southeasterly, in an air line, from Highland Park Reservoir. This creek lies between the two ranges of mountains called Chestnut Ridge and Laurel Hill, and is doubtless the nearest available source from which a sufficient volume of good water can be delivered by gravity alone into said reser- voir. Unfortunately, the mouth of the stream is nearly 100 feet below the level of said reservoir, but its bed rises quite rapidly as we proceed up the valley a few miles, until it attains an elevation of about 80 feet above said reservoir at a point about one mile above Resler's Run, and near the small village of Springfield. Beyond this point, the general slope of the valley is somewhat less, and the creek follows a tortuous course through a series of alluvial flats which have formed at the foot of the mountains. As the entire drainage area of Indian Creek is only about 125.7 square miles, and the natural flow of the creek in periods of drought is probably much less than the present water consumption in the city, it is obvious that the availability of this source must be contingent upon the construction, somewhere in the valley, of a capacious storage reservoir; also that the elevation of the water surface therein, when drawn to its minimum level, shall be such as to give an ample fall, in a distance not less than 43 miles, to Highland Park Reservoir. Assuming for this fall a grade of about 5.6 feet per mile in an economical steel pipe conduit, it follows that the aforesaid minimum water level in the Indian Creek storage reservoir must be at least 240 feet above the said city reservoir, or at an elevation of at least 1,310 feet above sea level. On examining the topographical map of the valley, however, it will be found that this elevation in the bed of the stream occurs at a point about 4 miles above the locality mentioned in the preceding paragraph, and also that the 90 REPORT UPON A GRAVITY WATER SUPPLY. drainage area at said point is only about 93 square miles, while at the first- named place it is 112.2 square miles. The elevation of the high-water level in the storage reservoir, on the other hand, is dependent upon the volume which must be impounded and the average area of the water surface. As will be shown below, this volume should safely be about 27,400,000,000 gallons, which can be represented by a stratum 84 feet thick with an average area of 1,000 acres, or by one of 42 feet thickness, with an average area of 2,000 acres. Such large areas and volumes, however, are difficult to obtain in a relatively narrow and steep valley like that of Indian Creek, without a very high dam; and as the ultimate cost of the project is largely in- fluenced by the dimensions of such a structure, it will be seen that its proper location involves many careful computations for a variety of dif- ferent sites. For want of time, only three such sites have thus far been considered, and their study has resulted in the provisional selection of the dam site at a point in the valley about one mile above the mouth of Resler's Run, where the elevation of the creek's bed is about 80 feet above Highland Park Reservoir, or 1,150 feet above sea level. The drainage area above this site is about 112 square miles. From the best available data, it is estimated that 40 per cent, of this surface is cleared land, while the remaining 60 per cent, is forest and brush. As there are no coal seams or other minerals here which can be worked profitably, the land is used only for farming and timber purposes; hence it is found from the census of 1890 that the entire population on said area, which embraces parts of the townships of Springfield and Salt Lick, in Fayette County, and part of Donegal in Westmoreland County, does not exceed 3,300, or an average density of 30 per square mile. A few hamlets, such as Springfield, Mill Run, Indian Head and Jones Mills, occur on the water-shed, but with the exception of Mill Run, they will not be affected by the storage reservoir, nor will their presence be of moment to the latter from a sanitary point of view. Without entering upon a description of the various geological strata which appear in the bed of the creek and sides of the valley, it may briefly be stated that no coal seams are known to exist below the site selected for the dam, and that the underlying rock is mostly a hard sandstone, with an occasional layer of hard limestone; while above said site, the rock appears to be chiefly a durable sandstone up to the coal deposits, where shales overlaid by sandstone, etc., are found. So far as could be determined within the available time, the coal is generally above the high water level of the proposed reservoir, and hence the latter will not interfere materially with future mining operations, if such should ever be undertaken on a large scale. It is therefore extremely probable that an excellent foundation for a high masonry dam can be AVAILABLE QUANTITY. 91 secured without difficulty, and that an ample supply of suitable material for making such a dam can be obtained from conveniently situated quarries. From the character of the rocks, and the entire absence of any de- posits of glacial drift, it may be inferred that the surface soil is of a sandy nature, as is in fact the case. For this reason, the water which is yielded by such a drainage area will be very soft, and when stored in a large reservoir it will soon become very clear. With proper pre- cautions to prevent the inflow of surface drainage waters in the vicinity of the inlet to the conduit, the delivery of water can be assured which will usually be perfectly clear, and will be affected only in times of freshet by a slight degree of turbidity due to mineral matter. It may, however, be anticipated that the large proportion of timber land on the water-shed will supply the water with more or less vegetable organic matter, which may occasionally impart to it a slight color, along with a disagreeable odor and taste, due to the development of certain minute aquatic plants, such as are found in all natural lakes or ponds; but as these conditions occur only at long intervals, and last only for a short period of time, an objection on this account to such a source of potable water supply cannot be regarded as well founded. Taking all the conditions into account, as briefly outlined above, it is fair to conclude that the source under consideration is excellent, and that the quality of the water taken therefrom will compare favorably with the best public supplies now in existence. Available Quantity. As mentioned in the foregoing, the drainage area above the site of the proposed dam is 112 square miles, and the question now arises as to the quantity of water which may be collected therefrom. Obviously this depends chiefly upon the magnitude and seasonal distribution of the rainfall; and as no systematic gaugings of Indian Creek have ever been made, we can only apply to this water-shed the results of long- continued observations of stream discharge in other similar drainage basins which receive practically the same amount of rainfall. A brief reference to the latter is therefore necessary. So far as can be learned, the only gaugings of the rainfall on the Indian Creek basin, are those which were made by agents of the Western Water Company during the four years from 1893 to 1896, inclusive, and which exhibit an average precipitation of 35.65 inches, with a minimum of 31.11 inches in 1894. The rainfall at a number of stations around this basin has, however, been observed more or less regularly and carefully for some years past, and the data have been published in the Report of the Secretary of Internal Affairs of Pennsylvania for the year 1895, 92 REPORT UPON A GRAVITY WATER SUPPLY. and subsequently in the reports of the U. S. Weather Bureau. From these documents, the data relating to the following nine stations, nearest to and surrounding the Indian Creek basin have been compiled and studied along with the records relating to the latter:- No. STATIONS. c s Average Yearl Rainfall. Inches. Minimum Rainfall, Inches. S.E , , 01 « s D 5 > E I Johnstown, Cambria Co ..1885-95 II 46.07 37-55 1895 2 Stoyestown, Somerset Co . . .1891-95 5 44-47 40.29 1892 3 Somerset, Somerset Co ..1888-95 8 4844 3148 1895 4 Confluence, Somerset Co ••1875-95 21 44-45 35-n 1895 5 Uniontown, Fayette Co ..1888-95 8 49-51 38.65 1895 6 Greensborough, Greene Co ■.1889-95 7 42.99 33-76 1893 7 Lock No. 4, Washington Co. .. . ..1886-95 IO 40.74 24.88 ^895 8 W. Newton, Westmoreland Co. . .•1891-95 5 34-34 29-57 1895 9 Lycippus, Westmoreland Co... . ■•1893-97 5 41-34 31-85 1895 IO Indian Creek, Fayette Co ■•1893-96 4 35-65 31.11 1894 Averages 8.4 42.80 33-42 According to the foregoing table, the average yearly rainfall of the In- dian Creek region is 42.80 inches, with an average minimum of 33.42 inches in the driest year; but it must be remembered that the periods for most of the stations embrace only a few years, and hence it is fair to presume that the true average will be somewhat greater than 42.80 inches, and similarly, that the minimum at Indian Creek will be somewhat less than the record of 31.11 inches in 1894. On comparing these figures with the precipitation records of other drainage basins where the stream flow or run-off has been regularly and carefully measured for many years, it will be found that they agree best with those of the Sud- bury River, near Boston, Mass.; and as this water-shed is classed among those which yield the smallest percentage of the precipitation as stream flow, it will be prudent to base our computations for storage and run-off upon the data relating thereto. These data are essentially as follows:-Area of water-shed, 75.2 square miles in a hilly and rocky region; mean annual rainfall for 23 years, from 1875 to 1897, inclusive, 45.77 inches; least rainfall for one year, 32.78 inches in 1883; average depth of rainfall collected yearly or running off in the river, 22.22 inches; least depth of rainfall collected, 11.19 inches, in 1883. From these records, which are considered to be the most complete and carefully kept in this country, Mr. Frederic P. Stearns, the Chief Engineer of the Boston Metropolitan Water Board, AVAILABLE QUANTITY. 93 has prepared a table showing the storage required per square mile of water-shed for different rates of draft in gallons per day, in order that the reservoir will not become empty in times of long-continued drought; and by applying this table to the case under consideration, the necessary capacity of the proposed reservoir can readily be determined. For this purpose, it will be assumed that the draft will be 75,000,000 gallons per day, and that the area of the Indian Creek water-shed above the dam is 112 square miles, of which about 3 per cent., or 3.28 square miles (2,100 acres) is water surface, while the remaining 108.72 square miles is land surface. The said draft is at the rate of 690,000 gallons per square mile of land surface per day, and according to Mr. Stearns' table this requires a storage of 148,200.000 gallons per square mile of such sur- face, or a total of 16,112,300,000 gallons, which represents a supply of 75,000,000 gallons per day for 195 days, on the supposition that no rain whatever falls on the water-shed, and that the reservoir loses by evarpora- tion during this period a depth of 30 inches on an average area of 1,800 acres. In view of the rapid growth and enormous water consumption of Pittsburgh, however, and also the contingency that in a year of extreme drought the rainfall may be so distributed as to yield even less than has been experienced on the Sudbury River basin, it will be expedient to consider that the effective storage volume shall be at least 50 per cent, greater than the above figures, or about 27,400,000,000 gallons. This represents 346 days' supply at the rate of 75,000,000 gallons per day, or 282 days' supply at the rate of 92,000,000 gallons per day, or 173 days' supply at the rate of 150,000,000 gallons per day, without any rainfall, and allowing for evaporation as before; and it also represents what is required, according to Mr. Stearns' table, for a daily supply of 92,000,000 gallons from the water-shed. Another reason for referring particularly to this latter quantity, is that it represents the safe average capacity of three conduit pipes to the city, as will be explained in further detail below. This storage may certainly be regarded as ample for the relatively small drainage area of Indian Creek; but as it is entirely feasible in the future to supplement the yield of this basin by the flow from the adja- cent area of 105 square miles of Laurel Hill Creek, it may be proper to retain it for the purpose of making an estimate of the probable cost of the work. Obviously the dimensions of the dam will thereby be considerably increased, but the value of the work to the city will be in much larger proportion. To indicate what is involved in this larger storage, it may be mentioned that the height of the dam is thereby increased about 19 feet, its volume about 110,000 cubic yards, and its cost about $600,000; hence to compare the resulting cost of this scheme with that of another similar project which provides for an ultimate storage of only 16,112,- 94 REPORT UPON*A GRAVITY WATER SUPPLY. 300,000 gallons, said increased cost should be deducted from the subjoined estimate. A few words may also be added here in relation to the possible supplementary supply from Laurel Hill Creek, mentioned in the pre- ceding paragraph. It appears from the surveys and maps submitted by the Western Water Company, that such a supply will require the construction of a reservoir and dam of relatively moderate dimensions in this valley, from which a tunnel conduit about 39,600 feet, or 7.50 miles long, will convey the water thus collected into the proposed large Indian Creek Reservoir. At the site of said dam, the Laurel Hill Creek valley is much wider and the hillsides have easier slopes, than is the case at Indian Creek, so that a high structure with great storage capacity will be correspondingly more expensive. It is therefore suggested that said dam shall be adequate for only a partial development of the water re- sources of the drainage area, and that in times of freshet the surplus be allowed to escape. On this basis, the two water-sheds taken together may be regarded as capable of affording the city a safe ultimate supply of about 130,000,000 gallons per day during the driest three consecutive years for which data are available; and it may also be remarked that this is the longest period of time which experience has shown need be con- sidered in dealing with public water supplies. Owing to the lack of sufficient topographical details relating to the Laurel Hill Creek basin, it has been impossible to make an accurate estimate of the cost of the supplementary dam and reservoir mentioned, but from the data afforded by other similar works, it is believed that the sum of $1,300,000 will suffice to provide all that may be needed in this direction, while $1,700,000 will be required for the long tunnel to the Indian Creek Reservoir. The cost of the partial development of the Laurel Hill Creek basin may therefore be estimated at about $3,000,000; and in contrast thereto it may be mentioned that the estimate for the Indian Creek Reservoir and appurtenances is about $5,480,000, exclusive of any conduit work. Consumption. It has been assumed in the foregoing that the proposed gravity works shall be capable of delivering at least 75,000,000 gallons per day, inasmuch as the present consumption in the city, during seasons of greatest draft, has nearly reached this amount. Taking the entire esti- mated population at 300,000, we thus obtain the enormous rate of 250 gallons per head per day, which is practically twice as much as is com- monly regarded a very liberal allowance in other large cities. From a recent compilation of the water consumption in 100 American cities of over 30,000 inhabitants, which embraces every large city in the Union, CONSUMPTION. 95 and an aggregate population of about 16,600,000, it is found that the average is 112 gallons per capita, and that if classified according to popu- lation, the averages are as follows :- For cities of from 30,000 to 100.000 inhabitants, 105 gallons per head. " " 100,000 " 300,000 " 106 " " " " 300,000 " 600,000 " 122 " " " " 600000 " 2,000,000 " 116 " " This statement renders it clearly evident that the large consumption in Pittsburgh is highly abnormal; and if the fact that many of the large industrial establishments in the city are provided with independent sup- plies from the two rivers is taken into account, the conclusion cannot be resisted that much of this excessive use of water from the public mains is due to preventable waste. When it becomes necessary for a city to obtain a good gravity supply from a locality so far distant as Indian Creek, such a large consumption will inevitably lead to a great outlay for construction and fixed annual charges, and the utmost restriction of waste should become the rigid policy of the municipal administration. With such measures properly enforced, the daily consumption may readily be reduced to an average of 45,000,000 gallons, in which event the provision of a delivery of 75,000,000 gallons per day from the gravity conduit will be ample for a considerable term of years, or until a popula- tion of at least 400,000 is reached. It may be remarked in this connection, that the ultimate capacity of a gravity conduit must not be taken as the measure of the average daily consumption in a city, as unavoidable increments in rate of use usually occur at different seasons which, if continued for too long a time, will exhaust the available supply in the distributing reservoir, and thus lead to various dangers. From the experience of other cities, it has beeen found that where the distributing reservoir holds only a few days' store of water, the average daily consumption should not exceed 87 per cent, of the ultimate capacity of the gravity conduit; or expressed conversely, the seasonal increments of the consumption should not ex- ceed 15 per cent, of the average daily use throughout the year. When this limit has been attained, an additional supply must soon be provided in order that the possibility of a water famine may be averted. On this basis, an ultimate conduit capacity of 75,000,000 gallons per day corresponds to a daily average use of about 65,000,000 gallons, which should be a very liberal supply for a city of 435,000 inhabitants. The growth of the city will, however, doubtless continue after the said population has been attained, and hence any adequate plan for a gravity supply must take such future growth into account, as was in- dicated in the foregoing description of the Indian Creek basin and its probable capacity. The same comment is also applicable to the conduit, 96 REPORT UPON A GRAVITY WATER SUPPLY. which should obviously be designed so as to admit of subsequent incre- ments to the initial supply without materially interrupting its regular discharge. These essential points have been duly borne in mind in the following formulation of the Indian Creek project: and to present the same in definite terms, it will be assumed that the legitimate use of water in the city for all purposes can readily be reduced to an average of 150 gallons per capita per day, and that with its present estimated population of 300,000 and an average daily consumption of 45,000,000 gallons, an initial conduit capacity of 75,000,000 gallons per day will afford ample provision for growth during a period of from 10 to 20 years. Storage Reservoir and Dam. In the foregoing it was found that with a drainage area of 112 square miles, and a dam of sufficient height near the village of Springfield to afford an available or effective storage of 27,400,000,000 gallons, the Indian Creek basin can safely be depended on to yield a daily supply of 92,000,000 gallons; and that by diverting into the large reservoir thus formed a portion of the water collected from 105 square miles of the adjacent Laurel Hill Creek basin, the daily supply can be increased to about 130,000,000 gallons. It was also found that a constant and regular draft of 75,000,000 gallons per day from the Indian Creek basin alone, requires a reservoir with an effective storage capacity of 16,112,300,000 gallons. The last-named draft, however, affords insuf- ficient provision for future demands; and as comparatively little is gained by stopping the construction of such a dam temporarily at a lower level, with the expectation of raising its crest in the future, it will be expedient to finish the construction at once to its full height. In view of the magnitude of the undertaking, and to allow ample margin for subsequent increments of draft, the first-named effective storage volume of 27,400,000,000 gallons has been adopted as being a close approxima- tion to that which further study may demonstrate to be the most advan- tageous. It was also shown that, on account of the great length of the con- duit from Indian Creek to Highland Park Reservoir, the elevation of the lowest water level in the storage reservoir should not be less than about 1,310 feet above sea level. At this elevation, however, a large extent of alluvial flats will become exposed, and to avoid the resulting undesirable effects, the low-water level has been taken at the elevation of 1,320 feet above sea. The area of the reservoir at this level will be about 848 acres; its greatest depth of water at the dam will be about 175 feet, and it will contain about 13,150,000,000 gallons, which will not be available for use, since the effective storage capacity must lie STORAGE RESERVOIR AND DAM. 97 wholly above said level. As the latter is 27,400,000,000 gallons, the spillway level must be sought at an elevation corresponding to a total impounding capacity of 40,550,000,000 gallons, which is found at or near elevation 1,383 feet above sea; here the area of the water surface will be about 1,912 acres, and the greatest depth of water at the dam will be about 238 feet. Obviously, the adoption of any other structure than a masonry dam of the most massive description, for impounding such an enormous volume and depth of water, is not to be considered, and to compute the quantity of masonry needed for the purpose, the dimensions established by the engineers of the new Croton River Dam, now in process of con- struction near Yonkers, N. Y., have been adopted. From these com- putations and the preliminary sketch plans, it was found that the dam and its appurtenances will require about 605,000 cubic yards of various classes of masonry, exclusive of the rough stone work needed for bank protections, etc., and the better class of work for the superstructures of the valve houses. It may also be mentioned that these figures are based on the assumption that a suitable rock foundation will be se- cured at moderate depth below the existing surface, as will doubtless be the case. The large reservoir thus created will manifestly interfere with the public highways that now pass through and across the principal valleys, and hence the estimate must include the cost of such new roads and bridges as may be necessary to restore the means of communication in the district affected. A considerable quantity of land bordering on the flow line all around the reservoir must also be acquired by the city in order to prevent any direct pollution of the water, and more or less work must likewise be done on private premises beyond the aforesaid marginal area, to insure the purity of the numerous tributaries. Pro- vision has accordingly been made in the estimate for the purchase oi at least 3,100 acres of land in the valley, including the reservoir site, and for the construction of nearly 20 miles of public and private roads, with the necessary culverts and bridges. Among the latter structures, a suitable highway suspension bridge at a narrow place near the middle of the reservoir, and the adaptation of the crest of the high masonry dam for roadway purposes, have been included. Without reciting the numerous other items which enter into the design and cost of the dam and reservoir, it may suffice to state that the estimated cost of this part of the work is $4,985,000, to which 10 per cent, should be added for contingent expenses, thus making a total of $5,483,500. The prices adopted for the various items are believed to be ample, and if the asssumed land values are not greatly exceeded, the work can be completed within the said amount. It should, however, 98 REPORT UPON A GRAVITY WATER SUPPLY. be mentioned that no provision has been made for compensating owners of mill privileges on Indian Creek, in and below the reservoir site, as there are no mills in this portion of the valley which make use of water power. Tunnel Conduit. As the site of the proposed high dam is about 3.5 miles above the mouth of Indian Creek, and the lofty mountain range called Chestnut Ridge extends without interruption for the entire length of the valley to the Youghiogheny River, the outlet conduit from the storage reser- voir must either make a long detour through the lower part of said valley, or must pass in tunnel through the mountain. From considerations of ultimate economy, the latter plan has been chosen, so that the first part of the conduit will be a tunnel 26,400 feet, or 5.00 miles, long, beginning at about elevation 1,310 feet above sea at the north end of the dam. The ex- cavation through the rocky strata of the mountain is to be made about 11 feet in diameter, so as to admit of a strong brick lining to form a horseshoe-shaped conduit, 8.5 feet high and wide inside, with a grade of one in 2,500, and a maximum discharging capacity of about 150,000,000 gallons per day. This capacity corresponds to the ultimate average daily yield of 130,000,000 gallons computed above for the Indian Creek and Laurel Hill Creek basins combined, with an allowance of 15 per cent, increase over the average for seasonal variation in demand. Little argument is needed to demonstrate the expediency of adopt- ing at once the limiting dimensions for such a work, and of building it in such permanent manner as to avoid future enlargement and repairs. The principal item of its cost is the excavation of a passageway, or heading, large enough to allow the workmen to perform their task ex- peditiously, and after this has been done, the removal of the rest of the material is effected at relatively low rates. Between a suitable conduit of two-thirds of said capacity and the one here proposed, the difference in first cost will amount to only about $165,000, which sum is of slight significance in comparison with the large initial cost of nearly $1,000,000 for the smaller conduit. A subsequent enlargement of the conduit is manifestly impracticable, as the water supply to the city cannot be in- terrupted, and the construction of a parallel tunnel in the future will make the ultimate costs of the work excessive. It is therefore advisable to adhere to the size and capacity above indicated. The tunnel conduit above described will terminate on the western side of the mountain, at about elevation 1,299 feet above sea level in the valley of White Run, where a suitable overflow chamber, or waste weir, will prevent the masonry lining from being subjected to any undue internal water pressure. Its construction is to be facilitated by several TUNNEL AND STEEL PIPE CONDUITS. 99 deep shafts along its course, which will enable the work to be prose- cuted simultaneously in both directions at a corresponding number of points, as well as from the ends, and which will afterwards be equipped with brick ventilating stacks, or manholes, 4 or 5 feet in diameter, the remainder of the shaft excavation being refilled with the material origin- ally removed. The execution of the conduit work as thus planned will require about three years, while that of the reservoir and dam will require at least four years. Steel Pipe Conduits. From the end of the tunnel conduit, the ground descends rapidly to the general level of the tops of the lower ranges of hills between Chestnut Ridge and Pittsburgh, and its configuration is too irregular and unfavorable to admit of the construction of a continuous masonry aqueduct. A route might possibly be selected which would be charac- terized by a number of detached sections of such conduit, amounting in the aggregate to a length of several miles; but no effort was made in this direction, as the possibility of subsidences of the surface over the numerous coal mines which occur along any practicable route, renders the selection of such an aqueduct inexpedient. For this reason the use of riveted steel pipe alone has been considered for the remainder of the conduit. So far as can now be determined from the best available data, the distance in a direct line from the end of the aforesaid tunnel to High- land Park Reservoir is about 199,000 feet, or 37.70 miles. Such a loca- tion for the conduit is, however, impracticable on account of its passage over numerous intervening summits and ridges, which are at so great elevations above the hydraulic grade line as to require the construction of expensive and undesirable tunnels, particularly in the mining dis- tricts. It has, therefore, been necessary to find another feasible location for the pipe conduit, and such a one is shown on the accompanying map.* Doubtless this route is susceptible of much improvement, but as it has not been deemed advisable to spend further time in making elab- orate surveys, it is submitted merely as a rough possibility. Its length, following the undulations of the surface and with a liberal allowance for probable lateral detours, is 221,000 feet, or 41.86 miles, which is about 11 per cent, more than the air line distance mentioned above. The elevation of the end of the tunnel was stated in the foregoing to be about 1,299 feet above sea level, and it should be remarked that this refers to the bottom of the 8.5 foot conduit. In considering the pipe line, however, the elevation of the water surface in said conduit, which is at least 6 feet higher, should be taken into account. At the * See Plate No. n, opposite Page 100. REPORT UPON A GRAVITY WATER SUPPLY. 100 beginning of the pipe the elevation of the hydraulic grade line will ac- cordingly be at 1,305 feet above sea level, while at its end in Highland Park Reservoir its elevation will be 1,067 feet. The total available fall in the aforesaid distance of 221,000 feet is thus 238 feet, which gives a grade of one in 928.6 or 5.686 feet per mile; but in order to err on the safe side and to compensate for loss of head in entering the pipe, we may take for this grade, one in 935. For the required discharge let us adopt, as already set forth, 75,000,000 gallons per day, which is equiva- lent to 116.043 cubic feet per second. With these data, and taking for the coefficient (c) in the general Chezy formula (v = cPrs) for the mean velocity of discharge in a pipe an average value of c- 100, we will obtain:- 1. For a single line of pipe, required diameter=73 inches. 2. " double " " " " =55 " It must, however, be remembered that in the course of time the delivering capacity of all cast iron or steel conduits will be more or less impaired by an increasing roughness of surface^ ^te corrosion and the formation of organic growths on the interior; hence, while the assumed value of the coefficient (c) in the aforesaid formula is applicable to the average condition of the riveted steel pipe, it will be expedient to consider that its condition is inferior to the average, or such as may be expected to occur after it has been in use for 20 years. We should therefore add about 2 per cent, to the diameters as computed above, thus obtaining the values :- 1. For a single line of pipe, least required diameter=74 inches. 2. " double " " " " " =56 " Where a pipe conduit of such great length is to be used for a public water supply, and is, moreover, laid in ground which is liable to be dis- turbed by subsidences over coal workings, it is advisable to have at least two lines of pipe available, as it may be presumed that both will not be out of order at the same time. This plan has been adopted in esti- mating the cost of the proposed gravity conduit, and the figures are accordingly based on the use of two lines of 56-inch riveted steel pipes for the entire distance from the end of the tunnel under Chestnut Ridge to Highland Park Reservoir. After the aforesaid average daily supply of 65,000,000 gallons, cor- responding to a maximum of 75,000,000 gallons per day during periods of greatest consumption, which is afforded by these two pipes, has be- come inadequate, a third similar line must be laid, whereby the com- bined capacity will be increased to a maximum of about 112,000,000 gallons per day, corresponding to a daily average of about 97,000,000 gallons, which is a little more than the safe capacity of the Indian Creek P late No, II, CITY OF PITTSBURGH FILTRATION COMMISSION MAP SHOWING PROPOSED INDIAN CREEK RESERVOIR AND CONDUIT TO PITTSBURGH SCALE 10000 , । । ,20^00 FT JAN. 1899. INTERMEDIATE STRUCTURES ON PIPE CONDUITS. 101 water-shed, as already pointed out; and when this latter supply becomes insufficient, a fourth similar line must be provided, along with the tunnel from Indian Creek to Laurel Hill Creek, and the storage reservoir in the valley of the latter, as previously mentioned. The fourth pipe will thus make the combined conduit capacity about 145,000,000 gallons per day as a maximum, which corresponds to a daily average of about 130,000,000 gallons. This ultimate development practically exhausts the yield from these two mountain basins, and if still more water is required in the future, another source must be found. Intermediate Structures on Pipe Conduits. As the quick stoppage of the flow in any pipe conduit, such as is caused by the closing of a main valve, produces considerable incre- ments of pressure, and hence also severe stresses in the metal, it is expe- dient to minimize these undesirable effects in the long line under con- sideration by dividing it into at least four sections each of about 10 miles in length, at the ends of which a free discharge for the water is provided by means of either a suitable basin, or an overflow similar to a waste weir on a canal. With the former, the advantage of saving the water for use is gained; but as there has been no time available for finding proper locations for such intermediate reservoirs of serviceable magni- tude, and as their cost will add largely to the estimate, it has been deemed advisable to provide only for simple overflows or spillways at three or four convenient localities. Brief reference may also be made to the special constructions needed where the pipes cross under or over large streams, under rail- ways, and over coal workings. In all these cases, considerable ex- pense is involved in rendering the pipes reasonably safe against future disturbance by floods, derailment or subsidence. Furthermore, the con- duits should be coupled together with interposed stop-valves at frequent intervals in territory where danger from any of said causes may exist, so that in case of damage to one line, the flow of both pipes may be forced through a relatively short section of the other pipe at the expense of some loss of head, and then continue again in both pipes. Some reduction in the delivery will thus be incurred, but by no means as much as will happen if only one pipe remains in service for its entire length. The adoption of this scheme, however, leads to the use of a large number of main stop-valves. In addition to the foregoing items, a large number of air-valves at summits and blow-offs in depressions of the pipe lines, will be required, as well as a telephone line and various roadways for facilitating the con- struction and subsequent operation of the conduit. The different sec- tions must, moreover, be kept under constant supervision, as small leaks under high pressure may quickly enlarge and lead to great damage; 102 REPORT UPON A GRAVITY WATER SUPPLY. hence several dwellings, tool sheds, etc., for the conduit overseers, as well as for the keepers of the storage reservoir, must likewise be provided. Reference might also have been made to a great variety of other details connected with the pipe conduit, such as manholes to afford access to its interior, anchorages at its ends and intermediate points, masonry for carrying minor natural water-courses under or over the conduit, the various easements and mining rights needed for the con- struction and future protection of the work, etc.; but as this report has already greatly exceeded the limits originally designed therefor, all these other matters are accordingly omitted. It may, however, be of interest to remark that in the hands of an energetic and experienced contractor, the pipe conduit can readily be completed within a period of three years. Estimated Cost. The detailed estimate of the cost of the entire gravity system of water supply from Indian Creek may now be conveniently grouped into the following general items :- i. Masonry dam and appurtenances $ 3,673,000 2. Clearing reservoir site of timber, brush, earth, and vegetable mould, along with sanitary work beyond limits of territory acquired 730,000 3. Construction of necessary public and semi-public roads, culverts, bridges, fences, railings, etc., together with purchase of land for site, and compensation for buildings removed 582,000 4. Tunnel conduit, 8.5 ft. diameter, and 26,400 ft. long, with necessary shafts and ventilating manholes, complete 1,167,200 5. Two lines of 56-inch riveted steel conduit pipe, each 221,000 ft. long, with the necessary valves, overflows, creek and railway crossings, mason- ry and other appurtenances, complete 5,58345° 6. Rights of way for tunnel, shafts and pipe conduit with appurtenances, purchase of coal mining rights, supporting roofs of exhausted mines to prevent subsidence, clearing land and grad- ing roadways for construction on rights of way, dwellings, etc., for reservoir and conduit overseers, telephone line, and expenses not otherwise enumerated 599,35° Sum of foregoing items $12,335,000 7. Add 10 per cent, for engineering, inspection, legal expenses and contingencies not now foreseen 1,233,500 Total estimated cost of work for a maxi- mum capacity of 75,000,000 gallons per day for the pipe conduit $13,568,500 ESTIMATES OF COST AND MAINTENANCE. 103 As already stated, when the average daily-water consumption in the city exceeds 65,000,000 gallons, which corresponds to the maximum deliv- ery of 75,000,000 gallons per day mentioned in the above estimate, it will be necessary to lay a third line of pipe. The cost of this line will probably be somewhat less than one-half of the above-named item for pipe conduits, since its construction will be greatly facilitated by the original work, and but little expense is involved for connecting with the various overflow channels and inlet chamber at the distributing reser- voir. An approximate estimate of the cost of said third line is $2,774,775, to which 10 per cent, should be added for contingencies, etc., as above, thus making a total additional cost of $3,052,250, in order to adapt the delivering capacity of the pipe conduits to an average daily con- sumption of about 97,000,000 gallons, with a maximum of 112,000,000 gallons per day. In like manner, when this latter quantity becomes inadequate, the development of a supplementary supply from the Laurel Hill Creek basin must be carried out, at an expense of about $3,000,000, as already indicated, a'nd a fourth line of pipe must also be provided at the aforesaid sum of $3,052,250, whereby the total cost of this final increment becomes $6,052,250. The works will then be adapted to the ultimate average daily supply of about 130,000,000 gallons, with a maximum of 145,000,000 gallons per day; and their probable total cost will have been as follows :- For original cost with two lines of pipe and average daily consumption of 65,000,000 gallons. $13,568,500 For addition of third line of pipe 3,052,250 For addition of fourth line of pipe and Laurel Hill Creek basin 6,052,250 Ultimate cost $22,673,000 Operating Expenses and Maintenance. The annual operating expenses of the gravity system of water supply outlined in the foregoing are quite small in comparison with those of a pumping and filter system. A force of six intelligent men with a few helpers, and the occasional employment of other manual and team labor, will suffice to keep the conduits, storage reservoir, buildings, accessory roadways, bridges and culverts, and the telephone line in good order, at an estimated expense of about $14,000 per year, on the average; but it should be distinctly understood that this sum does not include any allowance for extraordinary repairs or renewals. To meet the latter expenditures, drafts may properly be made upon the accumu- lation of money in the sinking fund, which may be established for the payment of the bonded debt incurred for constructing the works. 104 REPORT UPON A GRAVITY WATER SUPPLY. In fixing the term of years for the maturity of such a sinking fund, it will be proper to discriminate between those portions of the works which are of permanent value and indefinitely long durability, such as lands, easements, mining rights, the great masonry dam and its appurtenances, the tunnel conduit, overflow-channels, roadways, etc., and the remaining portions which are subject to deterioration or decay, such as the riveted steel conduits, with their various valves and appur- tenances, the iron or timber roadway bridges, minor masonry objects, wooden buildings for overseers, telephone line, etc. For the first-named class, it may justly be urged that the sinking fund term should not be less than 100 years; but as it is generally considered expedient to maintain the credit of a large municipality at a high standard, in order that it may be enabled to borrow money at low rates in case of emer- gency, a period of 60 years has often been adopted as a limit. For the second class of structures, on the other hand, it is fair to assume an average life of about 40 years, and hence this term may be taken for the sinking fund for the corresponding part of the original bonded debt. For the first outlay of $13,568,500 mentioned above, the cost or value of the permanent portions of the work is estimated at $7,379,020, while that of the remaining portions is $6,189,480. Assuming sinking fund terms of 60 and 40 years respectively, for these two sums, and considering that interest at the rate of 3 per cent., compounded annu- ally, will be paid for the use of the money accumulating in these funds, then the annual contributions from the city to said funds must be 0.6133 and 1.3262 per cent, of the respective sums or principals. The annual payment into the former fund will accordingly be $45,255.53, while that for the latter is $82,084.88, thus making a total yearly sinking fund payment of $127,340.41. With reference to the annual interest on the bonded debt, a rate of 3.25 per cent, has been adopted, at the suggestion of some members of the Commission ; and by arranging the preceding items in tabular form, we now obtain the following statements of the fixed annual charges and operating expenses of the proposed gravity system :- I. For the period of years until the average consumption exceeds 65,000,000 gallons per day, with a maximum of 75,000,000 gallons per day for short times:- Interest at 3.25 per cent, on total estimated cost of works, $13,568,500 $440,976.25 Sinking Fund payment, as above 127,340.41 Ordinary operating expenses for salaries, wages, and minor repairs 14,183.34 Total yearly charges $582,500.00 CONCLUSION. 105 II. For the next period of years, after the addition of the third line of pipe, at a cost of $3,052,250, and until the average consumption exceeds 92,000,000 gallons per day, with a maximum of 112,000,000 gallons per day for short times:- Yearly charges for first period, as above $582,500.00 Interest at 3.25 per cent, on cost of third line of pipe, $3,052,250 99,198.13 Sinking Fund payment for term of 40 years, being 1.3262 per cent, of said cost of third pipe 40,478.94 Addition to operating- expenses, to round up 122.93 Total yearly charges $722,300.00 III. For the next period of years, after the addition of the fourth line of pipe and the Laurel Hill Creek basin, at a combined cost of $6,052,250, and until the average consumption exceeds 130,000,000 gallons per day, with a maximum of 145,000,000 gallons per day, for short times:- Yearly charges for second period, as above $722,300.00 Interest at 3.25 per cent, on cost of fourth line of pipe and Laurel Hill Creek basin work, $6,052,250... . 196,698.13 Sinking Fund payment for term of 40 years on cost of pipe, being 1.3262 per cent, of $3,052,250 40,478.94 Sinking Fund payment for term of 60 years on cost of Laurel Hill Creek basin work, being 0.6133 per cent, of $3,000,000 18,399.00 Addition to operating expenses, to round up 123.93 Total yearly charges $978,000.00 Conclusion. It will be noticed that in the foregoing I have confined myself to a brief technical description of the proposed gravity conduit, and have therefore left the comparison of this plan with other projects for im- proving the water supply of Pittsburgh to be drawn by the Commission and yourself. With reference to the feasibility of the plan, it may be remarked that the only element of engineering uncertainty attached thereto is the question of damage from possible subsidence of the ground over coal workings. The estimate, however, contains a fair allowance for the acquisition of ample mining rights, and presumably the state laws are adequate to protect the property thus acquired against en- 106 REPORT UPON A GRAVITY WATER SUPPLY. croachment or removal. From a financial point of view, on the other hand, there is little to say until the estimates for the other projects have been presented on the same basis as indicated above. Respectfully submitted, E. Kuichling, Civil Engineer. Rochester, N. Y., December 27, 1898. REPOR'r OF THE Resident Engineer, MORRIS KNOWLES, C. E. EXHIBIT 4. Mr. Allen Hazen, Consulting Engineer, Pittsburgh Filtration Commission. Sir:- I beg to submit, herewith, the report upon that portion of the work of the Filtration Commission which has been under my direct charge, since May 17, 1897, when I reported for duty. The experiments, for which arrangements were early made, and which were started as promptly as possible, were officially closed Sep- tember 1, 1898. Since then, the time has been largely occupied in com- piling data, and in preparing the reports; however, some little additional experimental work and investigations have claimed a portion of this latter period. CHAPTER I. General Outline of the Work. Organisation. Through the courtesy of Mr. E. M. Bigelow, Director of Public Works, and Member of the Filtration Commission, a room was assigned, May 19, 1897, for the use of the Commission, on the third floor of the City Hall, and this continued to be used as the office until Novem- ber 14, 1898. At this date, because of the need of more room, for the increased force, required for the early preparation of the report; also, to secure better light for the draftsmen, we moved to the fifth floor. But, a few days later, on November 19, the Herron Hill Labora- tory Building was assigned for the remainder of the work. Among the items of work first undertaken was that of making chemi- cal analyses of different samples of water and the services of the chemist, Dr. Walther Riddle, date from May 17, 1897. By the kindness of Messrs. Coster and Riddle, this work has been done in their private laboratory, and for this we are under many obligations to the firm; also, especially to Mr. Coster, in assisting at times when the work was particularly urgent. We began at once to collect samples for chemical analysis, from the Allegheny and Monongahela Rivers, and from representative taps in the cities of Pittsburgh and Allegheny. Samples were collected from a well which was drilled at that time adjacent to the boiler house at Brilliant. A discussion of these analyses will be found in the Chemist's Report, Appendix No. 1, and the results in Appendix No. 2. The special report upon this driven well, made by Mr. A. B. Shepherd, Superintendent of Bureau of Water Supply and Distribution, to the Director of Public 110 REPORT OF RESIDENT ENGINEER,-CHAPTER I. Works, will be found in Appendix No. 5. Considerable time was also occupied during the first few weeks in securing the necessary apparatus and utensils for the laboratory, and, in addition to his regular duties, the Chemist assisted the Resident Engineer in organizing the work. Sometime prior to the organization of the work upon the present basis, the Commission had arranged with Dr. Eugene Wasdin, Past As- sistant Surgeon, LTnited States Marine Hospital Service, to analyze repre- sentative samples of the Pittsburgh water supply and report upon the species of bacteria found therein. Dr. Wasdin's Report will be found in Appendix No. 3. His work was conducted in the laboratory of the Bureau of Health, Department of Public Safety. For this kindness, as well as for the many favors obtained later, until our own laboratory at Brilliant was completed, we are deeply indebted to this department and its officials, and it is desired at this time to express our thoughtful appreciation of this assistance. As it was not possible to secure the whole of Dr. Wasdin's time for the work of the Commission, other arrangements were ultimately made, and, upon July 1, 1897, Mr. Wm. R. Copeland, Assistant Biologist at the State Board of Health Experiment Station, Lawrence, Mass., reported in Pittsburgh to assume charge of this branch of the work. In the begin- ning, the work consisted in analyzing samples of river and tap waters, in preparing sketches for fitting up the laboratory at Brilliant and in secur- ing apparatus for the same. When the sand filters were started, July 23, 1897, the number of bacterial analyses was largely increased. The new laboratory at Brilliant was used after August 23, 1897, where the work has since been performed. The Bacteriologist has not only performed the necessary laboratory work, but has had direct charge of the experimental filter plant. Sand Filters. Acting upon the decision made at a meeting, held May 19, 1897, steps were immediately taken to construct, for experimental purposes, two sand filters at Brilliant with a settling basin. A description of these filters and a statement of the operations and the results obtained therewith, will be found in Chapter II. a Mechanical Filters, Preliminary steps were taken, upon May 22, 1897, to see what ar- rangements could be made to experiment with representative types of mechanical filters. Invitations to install their filters for experimental pur- poses, upon the basis of all expenses to be borne by the companies, were sent June 5, 1897, to the following filter companies :- EXPERIMENTAL FILTERS. 111 Cumberland Manufacturing Company, Boston, Mass. Morrison-Jewell Filtration Company, New York, N. Y. New York Filter Manufacturing Company, New York, N. Y. Continental Filter Company, New York, N. Y. Loomis-Manning Filter Company, Philadelphia, Pa. All of these companies declined, either at this time or later, to enter the test as originally proposed. After many conferences, agreements were drawn up, upon August 24, 1897, with the Cumberland Manufactur- ing Company and the Morrison-J ewell Filtration Company, for establish- ing their filters for experimental purposes. These agreements provided that each company should furnish, free on board cars at point of manufac- ture, a complete filter with alum apparatus, and other necessary acces- sories ; also, furnish a competent superintendent to supervise the erection of the same, and should loan the filter to the city of Pittsburgh, without recompense, for a period not later than to January I, 1899. It was also agreed that the city should pay all freight charges to Pittsburgh; also, should furnish all labor and material necessary for the erection and the necessary shelter, labor, power, alum, and water for operating the filters. It was furthermore provided, that, at the conclusion of the experiments, the city should take down, pack, and deliver free on board the cars at Pittsburgh, all parts of the filter. It was also agreed that each company should be informed from time to time as to the bacteriological, chemical, and mechanical results secured with its own filter, but these results were to be regarded as confidential until the final report had been made to Councils. These agreements were approved by Councils, and signed by the Mayor, October 13, 1897. Considerable time was thus occupied during the negotiations, and, again, after the agreements were signed, before the filters were actually received upon the ground. The apparatus first began to arrive November 4, 1897, but it was January 14, 1898, before the filters were in opera- tion. During the first few months of the experiments with the mechanical filters, representatives of the filter companies were in attendance, to advise in regard to the operation of their respective filters. Upon April 7, 1898, notice was received that the Cumberland Manu- facturing Company and the Morrison-Jewell Filtration Company had sold to the New York Filter Manufacturing Company, all patents and rights of their respective filters. A description of the Warren Filter, with the results of the experiments, will be found in Chapter III; and of the Jewell Filter, in Chapter IV. Worms Tile Filter. At Worms, Germany, filters are used which are composed of plates of artificial sandstone. Some of these plates had been secured by Hon. 112 REPORT OF RESIDENT ENGINEER,-CHAPTER I. Wm. Flinn, Member of the Commission, and tried by him in an experi- mental way. Through his kindness, negotiations were made with the American representative of Director Fisher of Worms, the inventor of the system, and six tiles were secured and set up at the experimental filter plant, according to the plans and directions furnished. They were placed in operation November 25, 1897, and continued until April 9, 1898. During this time, the American rights had been transferred to the Wormser Filter Plate Company, of St. Louis; and they, in a communica- tion dated March 29, 1898, asked permission to re-establish the plant and have the experiment continued. This was granted by the Commission, and, upon June 12, 1898, the test began again, under the general super- vision of a representative of the Wormser Filter Plate Company, and continued until the close of the experiments. A description of this filter plant, and the results obtained therewith, will be found in Chapter V. Berkefeld Filter. Upon November 12, 1897, a proposition was submitted by the Berke- feld Filter Company, requesting the Commission to consider the prac- ticability of placing household filters of their type, in all buildings through- out the city of Pittsburgh. The estimate of the company for installing 56,000 Berkefeld Home Filters, according to their system, was $560,000, and the annual operating expenses, exclusive of interest, was $189,000. The question was taken under consideration and a household filter of the Berkefeld type was submitted to us for the purpose of testing its efficiency. It may be stated that, in general, a large number of the bacteria in the water were removed, when the filter was carefully attended to. Frequent washings were necessary and occasionally the filter cylinder had to be sterilized by boiling. Surveys. It was thought advisable to have a survey made of certain flat- lands, along the north side of the Allegheny River, which might afford suitable sites for filters. This work was done, under the general super- vision of the Resident Engineer, by a party of five men from the City Engineer's office, under the direction of Mr. W. W. Fortune. They were employed upon this work as time could be spared from other duties and we are indebted to the Director of Public Works, and to Mr. Wm. R. Brown, City Engineer, in regard to this. This survey was begun August 17, 1897. The field work was finished October 27, 1897, and the plans were completed February 19, 1898. The survey included about 600 acres, which extend about three miles along the Allegheny River, from the east- erly line of Aspinwall to Montrose Pumping Station. Later, it was decided to secure information in regard to the topo- graphical character of the land along Squaw Run, which stream enters the MISCELLANEOUS STUDIES. 113 Allegheny River, a short distance above Aspinwall, and cuts through the foot-hills, bordering on the flat-lands, on the north side of the river. It was thought that the basin of this run might afford a good site for a large storage or settling basin for filters, located on the flat-land below. As the force of the City Engineer was busy at that time, a contract was made with Messrs. Wilkins and Davison, Civil Engineers, of Pittsburgh, tO' furnish the data and plans of this survey. The field work was begun May 9, 1898, and ended May 25, 1898, and the completed plans were de- livered June 8, 1898. The survey comprised about 200 acres which extend up Squaw Run for a distance of about two miles from the foot-hills. Maps prepared for these surveys have been transmitted to you as com- pleted. Gravity Supply. Upon May 26, 1898, a communication was received from the Western Water Company, requesting the Commission to consider whether it would be advisable for the city of Pittsburgh to secure a gravity water supply from a mountain water-shed in Fayette County, Pa. The company has certain rights in this territory and furnished the Commission with much detailed information and plans which had been made. It was deemed expedient, however, to secure additional data and a knowledge of the character of the material to be encountered in constructing the proposed dam and conduit. The additional surveys were made by Messrs. Jamison and Fogg, Civil Engineers, of Greensburg, Pa., acting for the Western Water Company. Information in regard to the drainage area and particulars in regard to the character of the geological formation along the conduit line, and the liability of having "sinks" in coal territory, were secured by the engineering force of the Commission. Miscellaneous Studies. Studies have been made of the past and present population in Pitts- burgh and of the probable future increase; similar studies have also been made in regard to the consumption of water. Investigations have also been made for a projected auxiliary supply of water for manufacturing purposes, which involved securing data of the manufacturing use of water and a study of the location of main pipes for this system. All of which information has been transmitted to you from time to time. During the summer and autumn of 1897, several epidemics of typhoid fever occurred in the vicinity of Pittsburgh and one within the city limits. Considerable attention and study were devoted to these for the purpose of investigating the cause of the excessive amount of this disease in the city. It was found that typhoid fever is generally existent here and in the suburban villages and boroughs; and the results of our investigations 114 REPORT OF RESIDENT ENGINEER,-CHAPTER I. indicated that epidemics are frequently to be traced to the use of infected milk, and also, to the use of contaminated well and spring waters. Besides the investigations above mentioned, information and data were obtained for Prof. W. T. Sedgwick, who was retained by the Commission to report upon "The Sources of Typhoid Fever in Pitts- burgh." A diagram was made, showing the location of the cases of typhoid fever, reported in the city, in 1897. Other statistical informa- tion was also secured; all of which will be found in Prof. Sedgwick's Report. Pollution Investigations. Prior to the engagement of the Resident Engineer, investigations were undertaken, under the general direction of Dr. W. J. Holland, Chair- man of "Committee of Water Analysis," to ascertain the extent and character of the pollution of the Allegheny and Monongahela Rivers and their main tributaries. Eight young men, students of the Western University of Pennsylvania, were employed, upon this investigation, dur- ing the Holiday vacation of 1896. They studied the sanitary condi- tion of the banks of the streams and the amount of pollution entering therein. The results are such that they cannot readily be placed in convenient form for publication, but they show that a large amount of sewage is being thrown into these streams from towns, villages, manu- factories, and dwellings all along their courses, even in the upper waters. Experimental Filter Plant. A brief description of the experimental filter plant is given here- with, and the exact details will be included in the reports of each of the several systems. The plant consisted of two sand filter basins, to- gether with a settling basin, built of concrete; located between the Alle- gheny Valley Railway tracks and the Allegheny River, about two hundred feet from the westerly end of No. 4 Boiler House, at Brilliant Pumping Station. Just west of the sand filter basin was located the filter building; in size thirty-four feet wide, by sixty-two feet long. Attached to the westerly end of this building, was the shed in which the experimental boilers were placed. The biological laboratory was located close by the sand filter basin, at the westerly end of a wooden building, which was used as a store-room and carpenter shop. Plate No. 12;-"General Plan of Experimental Filter Plant," opposite this page, shows the relation of these structures. Water was supplied by a six-inch cast iron pipe, leading from the force main in the pumping station yard. This pipe was about 240 feet long, and lead directly to the inlet chamber of the sand filter plant. A six-inch branch, about 75 feet long, led from the first line to the filter Plate No. 12. CITY OF PITTSBURGH FILTRATION COMMISSION GENERAL PLAN EXPERIMENTAL FILTER PLANT SCALE OF FEET JANUARY 1899 STORAGE SHED EXPERIMENTAL FILTER PLANT. 115 building. Steam was applied for uses in the filter building through a six-inch line, about 330 feet long, leading from the No. 4. Boiler House. A tap from this line furnished steam for heating the laboratory and supplying the autoclave. The water was distributed to the respective filters by a suitable arrangement of the piping. The pressure of the sup- plied water was about 150 pounds, which was too much for the butterfly valves on the inlets to the mechanical filters to control. It was neces- sary, therefore, to place a regulator on the main line in the building, which device reduced the pressure to about forty or fifty pounds. The effluents from the sand filters passed through three-inch pipes to a measuring vault located within the filter building, and thence out through a drain into the river. On its way, the water was caught in a barrel which allowed us to secure, with a small pump, filtered water for the purpose of supply- ing the laboratory, filling the sand filters after scraping, and such other uses as were found desirable. The effluents from the filters in the building were delivered into a large iron tank under the floor. This tank was sixteen feet in diameter, ten feet high, and was placed in the ground before the building was erected. Water was obtained from this tank for washing purposes, and delivered by two pumps, through suitable pip- ing, to the filters. The wash water and waste from the several filters ran into the river through a drain underneath the building.* Boiler Experiments. As large quantities of water are used in Pittsburgh for manufactur- ing purposes, in boilers and in various hydraulic devices, where it is stored in metal tanks, it was thought advisable to investigate the corrosive and incrusting, qualities of the Allegheny River water before and after filtration. For this purpose, three 25 H. P. boilers were kindly loaned to the Commission by the Oil Well Supply Company, and to this company we are deeply indebted for this favor, and for kind attention and advice in carrying out these experiments. A complete report of these tests will be found in Chapter VI. Asbestos. After the conclusion of the experiments by the Commission, it was brought to our attention that it was possible to use asbestos as a layer upon filters, and it was decided that certain tests should be undertaken with this material as a filter medium. As the time for this was limited, however, and the experiment somewhat incomplete, no statement of the results is given in this report. General. Frequent visits have been made to the experimental filter plant by interested citizens, also by residents of other places. The Commission made, *Arrangement of apparatus in filter building is shown upon Plate No. 13, opposite Page 116. 116 REPORT OF RESIDENT ENGINEER.-CHAPTER I. in addition to those by individual members, four official visits, viz.:- June 26 and July 23, 1897 ; June 18 and August 24, 1898. Upon the latter occasion, which was shortly before closing the experiments, Members of Councils and interested citizens were invited. Occasional visits were also made by the officials of the different filter companies, whose apparatus was being tested. The Resident Engineer has visited, at the request of the Commission, various filtration plants and investigated several devices not experimented with here. He also accompanied the chairman and a Committee, on an inspection of the experimental filter plants at Louisville, Ky., and Cincin- nati, Ohio, made April 19, and 20, 1898. During the investigations, it has been necessary to make frequent observations daily of the various gages located at the experimental filter plant. Observations of the turbidity of the river water, settled water, and effluents, were made daily. Frequent samples were collected during the day for bacterial determinations and, twice a week or more frequently, samples were collected for chemical analysis. All of this data has been reported from time to time, and weekly reports upon the progress of the work and results have been submitted to the Commission. Also reports of each week's results of the operations of the mechanical and Worms Tile Filters have been sent periodically to the respective filter companies. In carrying on this work the writer has, on many occasions, received kindly aid and support from the officials of the various city departments, from the authorities of the United States Weather Bureau and Engineer's Office, and many other citizens. To Mr. A. B. Shep- herd, Superintendent, of Bureau of Water Supply and Distribution, the writer is especially indebted for advice and valuable assistance. We are also indebted to the officials of the various railroads, and es- pecially to those of the Allegheny Valley Railway and Pennsylvania System, for courtesies in regard to facilities and arrangements for trans- portation and prompt delivery of all material needed in our experimental work. To all these gentlemen the writer wishes to express his thankful appreciation for their kindness. There have been employed, under the direction of the Resident Engineer, during the experiments, the following persons in the respective positions indicated, and, for their thoughtful appreciation and thorough attention to the work, the writer is deeply indebted:- Dr. Walther Riddle, Wm. R. Copeland, Frank B. Smith, Geo. W. Biggs, Jr., Wm. Toy, Chemist. Bacteriologist. Laboratory Assistant. Engineering Assistant. Filter Attendant. P late No. 13. CITY OR PITTSBURGH FILTRATION COMMISSION GENERAL PLANOF FILTER BUILDING JANUARY 1899 ORDER OF SUBJECTS. 117 Andrew Mount, Assistant Filter Attendant. Patrick Ging, " " " Wm. Birchell, Robt. C. Johnston, Observer. Fred. W. Henrici, " At different times, others have assisted in various capacities; also, mechanics and laborers have been employed during the construction of the plant and in dismantling the same. During the preparation of the report the force was largely increased for about six weeks, a maximum of twelve persons being employed for this purpose. The subjects in the Resident Engineer's Report have been consid- ered in the following order:- Chapter I-General Outline of the Work. Chapter II-Sand Filter Experiments. Chapter III-Warren Filter Experiments. Chapter IV-Jewell Filter Experiments. Chapter V-Worms Tile Filter Experiments. Chapter VI-Boiler Experiments. Appendix No. I-Chemist's Report, by Dr. Walther Riddle. Appendix No. 2-Tables of Chemical Analyses and Descriptions of Sources of Samples. Appendix No. 3-Bacteriologist's Report, by Dr. Eugene Wasdin. Appendix No. 4-Bacteriologist's Report, by Mr. Wm. R. Cope- land. Appendix No. 5-Report upon Driven Well Supply, by Mr. A. B. Shepherd. Appendix No. 6-Financial Statement. CHAPTER II. Sand Filter Experiments. Description. A plan and section of the sand filter plant is shown upon Plate No. 14, opposite page 118. The entire structure was made of concrete. The water was supplied through a six-inch pipe to the gate chamber, at the easterly end of the settling basin. Water from this chamber flowed, as desired, either into the settling basin or into either of the filters. There were also pipes which led from the settling basin into the filters. It was possible by this arrangement to supply either of the two filters with raw water or settled water. The settling basin held about 33,800 gallons, which allowed twenty-four hours sedimentation for the water passing through, when one filter alone was supplied with settled water, and at 118 REPORT OF RESIDENT ENGINEER,-SAND FILTERS. a five million rate. Suitable overflows, one at the gate chamber and one in the settling basin, provided that the head of the water upon the filters could be maintained at a constant elevation. The filter basins are about 25.2 feet by 12.7 feet, at the top of the walls. The exact area of the sand surface of No. I, at the beginning, was 285 square feet, and of No. 2, was 291 square feet; upon September 1, 1898, these figures were 273 and 279 respectively, owing to the lower level of the sand and the batter of the walls. The underdrains were of vitrified pipe, with broken stone and gravel placed about and above them, all of the ordinary construction and as shown upon the drawings. Most of the sand used was dredged from the Allegheny River, also a portion from the Ohio River, a short distance below the Point. A statement of the mechanical and chemical analyses is given upon page 121. The sand was deposited in six layers, each being carefully smoothed and leveled. The basins were then filled with water and after the sand had been in place for a few days, the depth was only 4.2 feet. Considerable sand was removed during the operations, by scraping, and there were only 3.1 feet left in Filter No. I, and 2.9 feet in Filter No. 2, after scraping, just before September 1, 1898. The effluent pipes of the filters were brought side by side into a small chamber located in the filter building. In this chamber were placed the necessary gates, meters, indicators, and gages for regulating and registering the quantity and determining the loss of head. There were also quarter-inch taps upon the pipes, from which chemical and biological samples were obtained. Meters were placed upon these pipes, after which the water passed through standard orifices. As air interfered with the action of the meters, the orifices were found more reliable and results from them, only, are used in making up the records. The orifices were in the botton of copper cans which were 12 inches in diameter and 12 inches high. The bottoms were made of brass plates one-eighth inch thick. On the side of the can there was an opening, with a two-inch pipe connection soldered on, for the entrance of the water. In front of the opening there was a screen with perforations, so that the velocity of the water was lessened and a direct downward current pre- vented. Ten standard orifices were drilled in the bottom plate, each of an average diameter of 0.503 inch. These orifices discharged into a trough below, which emptied into a pipe, delivering out under the building. On one side of the indicator there was a glass slide upon which a scale was fastened. This scale was graduated to read, upon one edge, in "Gallons per Orifice Daily," and upon the other, in "Million Gallons per Orifice per Acre Daily." In this way it was possible to determine, at one reading, both the actual quantity in twenty-four hours and the rate of filtration. Plate No. 14. SECTION atEF FILTER N?l SETTLING BASIN 33800 GALS. CAPACITY F LTER N?2 PLAN CITY OF PITTSBURGH FILTRATION COMMISSION SAND FILTERS SECTION at AB CD DESCRIPTION AND OPERATIONS. 119 OPERATIONS. The gates were changed to regulate the flow at 9.00 A. M., and, if ncessary, when the loss of head was great, again at 9.00 P. M. The at- tendants were instructed to keep the depth of water upon the orifices at the half million rate mark, so that one-half the number of orifices open, corresponded to the approximate rate of filtration. Orifices not in use were closed by rubber stoppers. Readings were taken at 9.00 A. M. 3.00 P. M., 9.00 P. M., and 3.00 P. M. Additional readings of the indi- cators were taken when a filter was being drained, preparatory to scrap- ing, and when first starting in operation again. The observation of the loss of head was also made at 12.00 M., which record is used in the tables. Water was first introduced into the settling basin July 15, 1897, and, upon July 17, it was allowed to pass slowly into the filters, in order to saturate the sand. Upon July 24, 1897, the effluent valves were first opened, and, except for the interruptions for scraping and a few delays which will be noted later, this plant has continued in operation during the twenty-four hours of every day until the close of the experiments. Periods of Operation,-Filter No. 1. Filter No. 1 was at first operated at an approximate rate of 2,000,000 gallons per acre daily. On August 15, 1897, the rate was changed to 3,000,000 gallons, which was maintained throughout the experiments. It was always operated with settled water except on the following occa- sions, when water direct from the gate chamber was used, viz.:- From 9.15 A. M., January 23, to 8.58 A. M., January 26, 1898. " 2.45 P. M., March 10, to 12.00 M., March 12, " " 11.45 A. M., " 25, to 3.45 A. M., " 26, " " 7.30 P. M., April 5, to 4.18 " April 6, " " 4.10 " May 11, to 6.02 P. M., May 14, " " 10.30 A. M., " 18, to 12.10 " " 19, " " 7.30 P. M., June 16, to 12.30 " June 19, " " 10.30 A. M., July 17, to 9.26 A. M., July 20, " " 11.06 " " 25, to 1.08 P. M., " 25, " Periods of Operation,-Filter No. 2. Filter No. 2 was at first operated at an approximate rate of 2,000,000 gallons per acre daily. At 9.20 P. M., August 15, 1897, it was changed to a 3,000,000 rate. " 9.05 A. M., December 19, " " " " 2,000,000 " " 9.14 " February 20, 1898, " " " 3,000,000 " " 9.00 " June 30, " " " " 5,000,000 " Filter No. 2 was at first operated with water direct from the gate chamber, except that, when running the second time at a 2,000,000 rate 120 REPORT OF RESIDENT ENGINEER,-SAND FILTERS. and at a 5,000,000 rate, settled water was used. During the periods while running at these two rates, there were the additional exceptions, when water direct from the gate chamber was used, viz.:- From 9.15 A. M., January 23, to 8.58 A. M., January 26, 1898. " 1030 " July 17, to 9.28 " July 20, " " 11.04 " " 25, to 1.08 P. M., " 25, " Cracks in Filter Walls. High numbers of bacteria were noticed in the effluents, in Novem- ber, 1897. Upon Saturday, November 13, 1897, Filter No. 2 was shut off to scrape, but the water did not run away as fast as usual. Upon looking for the reason, we found, in the dividing wall between the settling basin and the filter, a small crack close to the central well; this crack allowed the water from the settling basin to flow quite freely into the filter. The high bacterial numbers were probably caused by the water from the crack following down the concrete wall, which does not batter at this point, and thus into the underdrains without passing through sand. Upon emptying the settling basin, a similar crack was found at the corner of Filter No. I. Both filters were immediately drawn off and the cracks were repaired by cutting out dovetail grooves and filling with cement mortar. Both filters were scraped at this time and were put into operation again at 12.22 P. M. November 17, 1897. The surface of the filters, and the sand to some depth, at the point of repairs, became disturbed during this work; the sand surfaces also became slightly frozen. It is believed that these causes contributed to the large numbers of bacteria found in the effluents, for a few days afterward, and, to a lesser degree, throughout the cold season. It is believed, however, that the repairs were effectual; for, upon drawing down the settling basin upon December 7, 1897, with water still on the surface of the filters, no leaks were noticed. During the latter part of May and the early part Of June, 1898, the numbers of bacteria in the effluent, from Filter No. 1 were again high, and, when drawing down to scrape, upon July 15, 1898, a small leak was noticed at the place of the previous trouble. This time no attempt was made to stop the leak, but a small cement trough was built, out under the leak and over the sand; so that the water, instead of passing down between the wall and sand, was obliged to go out into the sand and be filtered. After this, no further trouble was noticed. Methods. Kitex the middle of December, 1897, it became our custom to scrape as soon as the loss of head became four feet. Before each scraping the levels were taken at eighteen points over the surface, and again after 121 ANALYSES OF SAND. scraping, before the surface was raked. The average of the differences gave the depth removed. On February 17, 1898, we began the custom of tamping the sand gently after scraping, for a width of about two inches from the walls, in order to compact it and prevent water finding its way down by channels between the wall and sand. On and after November 23, 1897, the filters were filled with filtered water from below after each scraping. ANALYSES OF SAND. The following tables contain the results of the analyses of all the samples of sands which were collected. Some were of sand dredged from various places in the vicinity of Pittsburgh, and others of that used in the sand filters. Table A. Mechanical Analyses of River Sand. No. Calendar Date of Collection. Place of Collection. Effective Size, M. M. Uniformity Coefficient. Remarks. 386 June 3, 1897, Allegheny River O.32 2.1 Dredged near 43d Street. 389 " 15, " cc cc 0-33 1-9 387 " 24, " Pile at Brilliant O.27 2.6 Used in filters. 388 " 24, " CC CC c( O.27 2-7 c c c c c c 475 August 3, 1898, Allegheny River 0.26 1.6 Dredged near Tarentum. 476 " 3, " cc c c O.19 1.8 CC cc cc 477 July 26, " c c c c 0.28 2.1 " " 43d Street. 478 " 26, " cc cc O.27 1.9 . << 11 << << 479 " 26, " cc cc O.27 2.1 " " 16th " 480 " 26, " Ohio River °-33 1.8 " " Point. Table; B. Chemical Analyses of River Sand. • Calendar Iron and Calcium Carbonate. Silicates and No. Date of Place of Collection. Aluminum Insoluble Collection. Oxides. Matter. 386 June 3, 1897, Allegheny River 2.25 0.91 96.84 387 " 24, " Pile at Brilliant 4.92 0-47 94.61 388 " 24, " U cc cc 3-89 0-53 95'49 475 August 3, 1898, Allegheny River 0.73 0-59 98.68 476 " 3, " cc it 0-97 0.36 98.67 477 July 26, " (C (( I.04 0.46 98.50 478 " 26, " cc cc 0-54 0.31 99-15 479 " 26, " cc cc 1.07 O.76 98.17 480 " 26, " Ohio River I-32 O.71 97-97 122 REPORT OF RESIDENT ENGINEER,-SAND FILTERS. Chemical Analyses of Sand Used in the Sand Filters. Samples Collected,-July 13, 14 and 13, 1897. Table C. Source of Sample. Effective Size, M. M. Uniformity Coefficient. Filter No. i O.3O 2.0 Filter No. 2 O.3I 2.0 Note:-The above results represent the averages of analyses of the samples collected from each filter. A sample was collected from the up-stream and from the down-stream end of each of six layers as the sand was placed in position. Table D. Chemical Analyses of Sand Used in the Sand Filters. PARTS BY WEIGHT.- Iron and Calcium Carbonate. Silicates and Source of Sample. Aluminum Oxides. Insoluble Matter. Filter No. i O.98 1.32 9770 Filter No. 2 O.96 i-35 97.69 Note:-An average sample of the sand in each filter was made by taking a portion of each sample collected. Table B. Condition of the Sand at Various Depths in the Sand Filters, After a Use of Fourteen Months. Samples from No. 1, Collected September 16, 1898. " " "2, " " 14, " Percentage Depth below Carbonate the Surface. No. i. | inch 0.39 1 " 0.21 2 " 0.45 3 " 0.30 4 " 0.27 6 " 0.52 8 " 0.61 10 " 0.18 12 " 0.30 14 " 0.23 16 " 1.00 18 " 0.67 20 " 0.54 22 " 0.48 24 " 0.36 26 " 0.55 28 " 0.48 30 " o-49 32 " 0.89 34 " 0.54 36 " 1-57 of Calcium by Weight. No. 2. o-57 0-43 o-39 0.36 0.64 0.64 0.46 °-39 0.25 o-39 0.13 O.II 0.13 0.48 o-57 0.5° 0-54 0-33 0.89 Ammonia in Parts Bacteria Per Gram. Albuminoid. No. 1. No. 2. No. 1. 2,440,000 1,720,000 11.OO 340,000 1,080,000 6.00 230,000 250,000 3.00 100,000 190,000 2.20 60,000 205,000 1.00 32,000 177,000 2.50 32,000 45,000 1.50 35,000 27,000 1.50 49,000 44,000 1.25 30,000 24,000 1.00 20,000 22,000 2.00 35,000 20,000 0.80 23,000 12,000 3.00 19,000 9,500 2.50 25,000 11,000 0.90 12,000 11,000 0.60 6,400 8,900 1.20 7,300 8,400 0.80 7,300 8,400 0.80 6,000 2.00 10,000 1.20 Per 100,000. Free. No. 1. 3-50 2.50 3-25 0.50 4.00 0.20 2.00 0.80 1.50 i-5o 1.20 0.50 0.00 0.00 0.50 0.00 0.90 0.90 0.90 i-5o 1.00 Averages, 0-53 o-43 168,000 204,000 2.22 1-25 DISSOLVED OXYGEN. 123 Dissolved Oxygen. Numerous samples of applied water and effluent were collected, from time to time, to determine the amount of "Dissolved Oxygen" in the water before and after filtration. The following table gives the results of these determinations:- Table F. Calendar Date of Collection. AMOUNT OF DISSOLVED OXYGEN, Gate Chamber. Settling Basin. -PER CENT. OF Filter No. 1. SATURATION. Filter No. 2. October 29, 1897 95-6 91.8 834 83-7 November 3, 85-5 834 81.4 8l.O 12, cc 9i-5 92.0 86.2 76.4 December 1, (( 90.5 91.6 81.4 96.O TO, 96.4 99-9 94-i 87.9 15, 95-7 90.8 80.5 81.3 22, 94-6 93-8 85-8 83-5 28, • * 9i-3 90.2 874 86.2 January 6, 1898 ,98.7 97-6 90.4 91.2 12, 96-3 954 91.6 92.1 20, 84-9 88.1 85-8 80.2 28, cc 83-7 82.9 80.4 81.3 February 3, 91-4 89.6 837 84-3 9, cc 81.6 79-7 81.5 797 15, cc 9i-5 86.8 87-3 81-3 21, 91.2 90.6 82.7 80.8 March 4, (( 924 91.6 854 86.3 11, 9i4 84.6 87-3 17, 92.6 90-9 86.4 87-3 26, cc 89.0 9i-9 84-7 894 April 1, CC 92.2 89-3 82.2 83-2 4, 90.8 90.2 81.8 834 11, cc 89.8 90.2 87-3 86.2 22, 66.0 67.1 67.6 64-9 25, cc 96.9 92.6 80.9 77-3 May 2, cc 85-2 85.8 73-3 65-0 9, 100.0 98.3 100.0 674 16, 78.2 79-o 66.8 66.0 23, 88.1 874 55-2 48.0 June 6, 98.8 544 68.2 724 13, 91.0 85.0 37-i 5i-5 20, 79-i 9i-5 59-8 39-i 27, 94-7 81.1 57-8 53-9 July 5, 82.6 83-0 364 45-3 11, 964 944 58.7 66.6 18, cc 71.1 734 52.6 25, 100.0 100.0 67.0 69.1 August 1, 694 67-9 34-8 5°-5 8, 61.1 60.4 37-2 43-9 15, 89.9 98.0 40.9 53-o 124 REPORT OF RESIDENT ENGINEER,-SAND FILTERS. BACTERIAL EFFICIENCY AFTER SCRAPING. In order to determine the efficiency of the sand filters directly after scraping, we occasionally collected biological samples, at short intervals of time, after the water began to flow from the effluent pipes. It must be remembered, in studying these records, that the filters were filled from below with filtered water. When first started, after scraping, a rate of 250,000 gallons per acre was maintained for fifteen minutes; the rate was then increased to 500,000 gallons, which was maintained for another fifteen minutes; at the expiration of each successive fifteen min- utes the rate was increased half a million, until the desired operating rate was secured. The results of the bacterial determinations are given in the following table:- Table G. Bacteria in Effluents from Sand Filters, after Scraping. Calendar Date, 1898. Time. Bacteria Per Cubic Centimeter. June 16, 11.48 P. M. *Valve No. I, opened. ' " 16, 11.52 " 628 1.05 A. M. 186 2.05 " 210 " *7, 3.18 " 142 " T7, 4.06 " 690 " T7> 5-05 " 364 " *7, 6.05 " 628 " 17, 7.00 " 560 " 17, 8.00 " 374 " 17, 9.10 " 576 " 17, 11.00 " 770 " 17, 1.00 P. M. 840 " 17, 3-40 " 896 " 17, 6.15 " 204 " 17, 9-45 " 186 " 17, 12.00 A. M. 266 " 18, 3.16 " 576 " 18, 6.00 " 171 June 22, 1.23 A. M. Valve No. 2, opened. " 22, 1.28 " 240 " 22, 4-03 <c 143 " 22, 6.00 " 122 " 22, 7.00 " 90 " 22, 8.10 " 171 " 22, 9.20 " 131 " 22, 11-03 " 199 *Crack in wall, between Settling Basin and Filter No. I, was repaired upon July 15, 1898. See Page 120. BACTERIAL EFFICIENCY AFTER SCRAPING. 125 Calendar Date, 1898. June 22, Time. Bacteria Per Cubic Centimeter. 98 I36 143 58 i-i5 4.06 6.22 IO.IO P. M. cc cc cc CC 22, 22, 22, July 19, 1.00 A. M. Valve No. I, opened. 1-05 cc 862 19, 2.00 199 19, 3.22 I32 cc 19, 4.00 cc 169 19, 5-oo 291 CC 19, 6.00 cc 184 cc 19, 7.00 416 19, 8.00 cc 354 19, 9.20 544 July 9> 7-25 P. M. Valve No. 2, opened. 9, 7.27 cc 852 9, 9.28 cc 436 9, 10.15 251 9, 11.19 205 cc IO, 12.15 A. M. 546 c c 10, 2.15 cc 562 10, 3-24 221 cc 10, 4-i5 cc 7i8 10, 5-i5 692 10, 6.15 cc 492 10, 7-i5 496 IO, 9-i4 430 cc IO, 12.21 P. M. 272 cc IO, 3-2i (( 304 IO, 6.25 cc 230 IO, 10.21 762 cc II, 12.06 A. M. 144 cc II, 3-20 (( U5 cc II, 6.00 cc 84 II, 9-17 cc 74 II, 3-20 P. M. 80 cc II, 9-35 (( 64 cc 12, 3-37 A. M. 198 Aug. 21, 11-30 P. M. Valve No. 2, opened. 21, n-32 CC 238 cc 22, i-3o A. M. 106 22, 3-30 197 22, 5-30 c c 258 22, 7-30 319 22, 9-23 301 22, 12.00 M. 262 cc 22, 3-oo P. M. 240 CC 22, 6.00 CC 215 22, 9.10 cc 175 Note:-The turbidity and average numbers of bacteria in the applied water, at the time of the above tests, were as follows:- 126 REPORT OF RESIDENT ENGINEER,-SAND FILTERS. Date, 24 Hours Gate Chamber. Settling Basin. Turbidity. Bacteria Turbidity. Bacteria Ending 9.00 A. M. Per C. C. PerC. C. Tune 17, 1898 O.42 7,650 " 18, " 0.21 4,250 0.17 " 22, " 0.70 15,600 " 23, " O.42 5,950 July 9, " 0.05 10,350 0.04 11,900 " io, 0.05 8,100 0.03 6,100 " 11, " O.O4 10,250 O.O4 " 12, " 0.04 3,850 0.03 2,000 19, " 0.06 14,400 0.15 16,000 August 22, " 0.50 22,700 0.50 11,100 23> " 0.31 12,600 0.22 5,450 Tabulation of Results. The tables presented upon the following pages give the quantitative nd biological results secured, by days; also the totals and averages for ach month, and for the periods between scrapings. The results of the hemical analyses are given in Appendix No. 2, page 246 et seq. TABULATION OF RESULTS. 127 RECORD OF SAND FILTER No. 1, For the Month of July, 1897. Date. Hours Quantity in Gallons. Loss of Head in Feet. Turbidity. Bacti ria Per Cubic Centimeter. 24 Hours Ending 9.00 A.M. in Opera- tion. Total Passed. Rate of Filtration Per Acre Daily. Gate Cham- ber. Set- ting Basin. Efflu- ent. Gate Chamber. Settling Basin. Efflu- ent. 1 2 3 4 5 6 • 7 8 9 10 • 11 12 13 14 15 16 17 18 19 • 20 • 21 • 22 23 24 25 20.0 24.0 11,500 12,700 2 080 000 1 730 000 1,9)0,000 0.10 8,260 2,400 4,830 1,150 6,860 4,600 26 27 28 24.0 22.3 24.0 13,000 11,000 12,960 1,950,000 1 780 000 1 650 000 1,950,000 6.17 0.20 0.50 0.52 0.33 0.31 1,300 3,850 1,450 2,200 750 1,200 29 24.0 12,600 1,890,000 0.23 0.57 0.36 4,200 2 800 900 30 24.0 13,010 1,960,000 0.27 0.52 0.36 3,250 3,100 500 31 24.0 13,000 1,950,000 0.31 0.40 0.29 3,900 1,525 85 Totals, 186.3 99,770 14,990,000 Av'gs, 23.3 12,470 1,880,000 0.50 0.33 3,880 2,436 2,128 Notes:-Percentage of Bacteria removed, 45.2. The rates of filtration for Ei.ter No. 1 were computed by dividing the "Total Passed" by 0.00664. This figure represents the area of the sand surface, calculated from the preliminary measure- ments of the basin and gives rates slightly in error. These results, at first about one per cent, too small, gradually increase i to about six per cent, for the last month of the experiments, due to the fact that the area decreased as sand was removed by scraping. /Where two numbers are given for a certain date in the "Rate" column, the upper one gives the rate of filtration for the actual time in operation. The lower figure gives the rate for twenty-four hours and has been used in computing the total for the month. REPORT OF RESIDENT ENGINEER,-SAND FILTERS. 128 RECORD OF SAND FILTER No. 1, For the Month of August, 1897. Date. 24 Hours Ending 9.00 A.M. Hours in Opera- tion. Quantity in Gallons. Loss of Head in Feet. Turbidity. Bacteria Per Cubic Centimeter. Total Passed. Kate of Filtration Per Acre Daily. Gate Cham- ber. Set- tling Basin. Efflu- ent. Gate Chamber. Settling Basin. Efflu- ent. 1 24.0 12,970 1,950,000 0.38 0.22 0.20 7,250 1,675 46 2 24.0 13,220 1,990,000 0.47 0.11 0.15 3 24.0 13,160 1,980,000 0.52 0.09 0.09 725 1,000 104 4 24.0 13,100 1,970,000 0.60 0.08 0.08 900 825 48 5 24.0 13,190 1,980,000 0.66 0.08 0.08 675 1,450 79 6 24.0 13,260 2,000,000 0.72 0.10 0.07 750 1,275 54 7 24.0 13,320 2,000,000 0.83 825 250 12 8 24.0 13,200 1,990,000 0.96 0.07 0.07 625 2,275 40 9 24.0 13,170 1,980,000 1.10 0.10 0.06 10 24.0 13,160 1,980,000 1.21 0.08 0.03 625 575 16 11 24.0 13,440 2,020,000 1.34 0.06 0 01 575 375 28 12 24.0 12,850 1,930,000 1.61 0.80 0 17 4,075 850 84 13 24.0 12,460 1,870,000 2.00 14 24.0 13,130 1,980,000 2.54 1.00 0.44 4,400 3,500 28 15 24.0 13,110 1,970,000 3.13 0.21 0.23 1,875 1,100 68 16 24.0 18,860 2,840 000 4.20 0.16 0.18 17 22.0 9 840 1 610 000 1 480 000 5.52 0.15 0.14 2.150 675 50 18 20.0 *15,300 2 760 000 6,250 1,375 64 19 24.0 19.730 2,970,000 0.21 0.12 0.30 2,075 2,025 44 20 24.0 19,840 2,990,000 0.28 0.17 0.36 6,400 4,150 43 21 24.0 20,080 3,030,000 0.25 2,200 2,085 67 22 24.0 19,800 2,980,000 0.29 23 24.0 19,530 2,940,000 0.31 0.12 0.08 1,300 900 82 24 24.0 18,870 2,840,000 0.32 0.08 0 06 500 850 28 25 24.0 18,880 2,840,000 0.30 1,150 1,300 1,025 35 26 24.0 18,310 2,760,000 0.30 1,150 30 27 24.0 19,830 2,990,000 0.30 1,325 1,237 21 28 24.0 19,940 3,000,000 0.25 975 335 22 29 24.0 19,570 2,950,000 0.25 0.08 0.02 950 300 41 30 24.0 19,>60 2,990,000 0.32 31 24.0 19,990 3,010,000 0.25 0.02 0.01 2,362 825 21 Totals, 738.0 494,970 74,500,000 Av'gs, 23.8 15,970 2,400,000 0.19 0.13 2,089 1,283 46 Notfs:-Percentage of Bacteria removed, 97.80. * First Scraping; 0.04 feet removed, 325,210 gallons passed (48,900,000 per acre) since beginning. TABULATION OF RESULTS. 129 RECORD OF SAND FILTER No. 1, For the Month of September, 1897. Date. 24 Hours Ending 9.00 A.M. Hours in Opera- tion. Quantity in Gallons. Loss of Head in Feet. Turbidity. Bacteria Per Cubic Centimeter. Total Passed. Rate of Filtration Per Acre Daily. Gate Cham- ber. Set- tling Basin. Efflu- ent. Gate Chamber. Settling Basin. Efflu- ent. 1 24.0 19,990 3,010,000 0.25 0.02 0.01 1,225 1,100 17 2 24.0 19,900 3,000,000 0.25 0.05 0.03 3,050 1,212 21 3 24.0 19,960 3,010,000 0.30 0.09 0.04 3,075 975 26 4 24.0 19,970 3,010,000 0.29 0.04 0.04 2,536 1,150 22 5 24.0 19,960 3,010,000 0.27 0.04 0.04 2,125 800 14 6 24.0 20,000 3,020,000 0.28 0.04 0.04 7 24.0 19,350 2,910,000 0.30 1,550 625 22 8 24.0 19,820 2,980,000 0.32 0.04 0.03 2,400 962 13 9 24.0 19,730 2,970,000 0.37 0.05 0.04 1,350 8 10 24.0 19,800 2,980,000 0.45 4,538 3,100 10 11 24.0 19,810 2,980,000 0.44 0.03 0.03 1,613 1,350 9 12 24.0 19,800 2,980,000 0.43 625 1,050 8 13 24.0 19,860 2,990,000 0.40 0.04 0.03 14 24.0 19,870 2,990,000 0.37 4,950 975 7 15 24.0 19,830 2,990,000 0.34 0.03 0.04 1,545 720 6 16 24.0 19,790 2,980,000 0.39 0.04 0.03 1,593 875 12 17 24.0 19,910 3,000,000 0.42 0.04' 0.03 1,650 225 15 18 24.0 19,810 2,980,000 0.53 0.07 0.04 2,170 690 30 19 24.0 19,760 2,980,000 0.65 0.05 0.04 1,900 650 14 20 24.0 19,780 2,980,000 0.76 3,225 2,000 18 21 24.0 19,780 2,980,000 1.00 0.05 0.04 1,225 1,041 27 22 24.0 19,840 2,990,000 1.22 0.09 0.05 700 587 10 23 24.0 19,910 3,000,000 1.45 0.04 0.04 2,275 825 7 24 24.0 19,830 2,990,000 1.58 0.05 0.04 3,125 2,275 19 25 24.0 19,840 2,990,000 1.80 0.05 0.04 2,250 2,100 26 26 24.0 19,850 2,990,000 2.13 0.05 0.05 9,575 3,925 12 27 24.0 19,590 2,950,000 2.32 28 24.0 19,760 2,970,000 2.64 1,750 1,112 18 29 24.0 19,710 2,970,000 2.96 0.06 0.04 1,667 667 14 30 24.0 19,890 2,990,000 3.24 0.07 0.06 2,100 900 24 Totals, 720.0 594,700 89,570,000 ... Av'gs, 24.0 19,820 2,980,000 0.05 0.04 2,478 1,231 16 Note:-Percentage of Bacteria removed, 99.35. REPORT OF RESIDENT ENGINEER,-SAND FILTERS. 130 RECORD OF SAND FILTER No. 1, For the Month of October, 1897. Date. 24 Hours Ending 9.00 A.M. Hours in Opera- tion. Quantity in Gallons. Loss of Head in Fuet. Turbidity. Bacteria Per Cubic Centime per. Total Passed. Rate of Filtration Per Acre Daily. Gate Cham- ber. Set- tling Basin. Efflu- ent. Gate Chamber. Settling Basin. Efflu- ent. 1 24.0 20,100 ' 3,030,000 3.56 0.08 0.06 4,549 2,200 14 2 24.0 19,710 2,970,000 3.76 0.06 iO.05 5,525 2,400 32 3 24.0 19,950 3,000,000 4.25 0.05 0.05 5,625 2,975 18 4 24 0 19,700 2,970,000 4.26 5 24.0 19,770 2,980,000 4.56 0.05 0.05 3,362 3,300 12 6 24.0 19,800 2,980,000 4.83 0.05 0.04 1,876 2,237 15 7 24.0 19,820 2,980,000 5.32 0.04 0.03 18,550 2,700 15 8 24.0 19,890 2,990,000 6.07 0.04 0.03 17,363 6,500 25 9 24.0 19,750 2,970,000 7.01 0.03 0.03 62,325 58,750 23 10 3.7 * 60 60 000 1 0 0 0 0 0.03 0.03 20,550 14,000 24 11 23.6 19,400 2 970 000 2 920 000 0.40. 0.03 0.03 22,575 177 12 24.0 20,080 3,030,000 0.35 0.03 0.03 13,700 12,562 84 13 24.0 19,910 3,000,000 0.34 0.03 0.03 14,675 16,100 35 14 24.0 20,050 3,020,000 0.33 0.03 0.03 17,150 12,000 26 15 24.0 20,100 3,030,000 0.34 0.03 0.03 27,300 19,000 26 16 24.0 20,060 3,020,000 0.34 0.03 0.02 19,950 16,475 24 17 24.0 20,100 3,030,000 0,26 0.03 0.02 29,750 7,813 19 18 24.0 20,100 3,030,000 0.30 0.03 0.03 19 24.0 20,090 3,030,000 0.33 76,913 51,025 25 20 24.0 20,050 3,020,000 0.37 0.03 0.03 93,450 53,175 21 21 24.0 19,980 3,010,000 0.40 0.03 0.03 99,600 58,500 22 22 24 0 19,890 2,990,000 0.43 0.03 0.03 159,500 76,500 17 23 24.0 19,830 2,990,000 0.47 0.03 0.02 151,250 47,250 16 24 24.0 19,850 2,990,000 0.53 0.03 0.03 196,500 58,050 17 25 24.0 19,810 2,980,000 0.59 0.03 0.02 26 24.0 20,090 3,030,000 0.67 0.03 0.02 94,500 45,875 22 27 24.0 19,910 3,000,000 0.74 0.03 0.02 118,500 44,075 21 28 24.0 19,900 3,000,000 0.84 0.03 0.02 155,000 89,375 28 29 24.0 20,060 3,020,000 0.92 0.02 0.02 206,500 102,125 51 30 24.0 19,990 3,010,000 1.05 0.02 0.02 183,750 119,000 40 31 24.0 19,800 2,980,000 1.17 220,300 134,062 61 Totals, 723.3 597,600 90,010,000 Av'gs, 23.3 19,280 2,900,000 0 04 0.04 72,878 39,186 32 Notes:-Percentage of Bacteria removed, 99.96. * 2d Scraping; 0.06 feet removed, 1,012,780 gallons passed (157,040,000 per acre) since 1st Scraping. TABULATION OF RESULTS. 131 RECORD OF SAND FILTER No. 1, For the Month of November, 1897. Date. 24 Hours Ending 9.00 A.M. Hours in Opera- tion. Quantity in Gallons. Loss of Head in Feet. Tukbidity. Bacteria Per Cubic Centimeter. Total Passed. Rate of Filtration Per Acre Daily. Gate Cham- ber. Set- tling Basin. Efflu- ent. Gate Chamber. Settling Basin. Efflu- ent. 1 24.0 19,940 3,000,000 1.33 0.03 0.02 2 24.0 19,940 3,000,000 1.54 0.03 0.03 111,000 103,250 45 24.0 19,780 2,980,000 1.71 0.06 0.04 90,000 20 4 24.0 20,000 3,010,000 1.89 0.04 0 03 66,475 50,300 35 5 24.0 19,750 2,970,000 2.06 0.04 0.04 72,875 76,525 26 6 24.0 19,950 3,000,000 2.19 0.05 0.03 27,000 72,500 31 7 24.0 19,810 2,980,000 2.38 0.06 0.04 16,063 41,913 32 8 24,0 19,990 3,010,000 2.65 0.04 0.04 9 24.0 19,850 2,990,000 2.87 0.04 0.05 7,850 17,425 26 10 24.0 19,750 2,970,000 3.05 0.16 0.10 8,550 13,288 24 11 24.0 19,840 2,990,000 3.38 0.08 0.06 6,375 4,600 22 12 24.0 19,830 2,990,000 3.65 0.11 0.08 13 24.0 19,400 2,920,000 4.19 0.23 0.10 6,500 6,113 53 14 22.0 14,610 2 400 000 2 200 000 4.82 8,100 8,310 85 15 2.5 330 480 000 5 0 0 0 0 16 0.0 0 0 15,700 643 17 0.0 * 0 0 0.70 0.70 21,350 18 20.6 15,560 2 780 000 0.35 1.00 0.44 29,900 21,325 843 19 24.0 19,960 3,010,000 0.50 0.88 0.50 17,950 21,950 24,400 1,701 20 24.0 19,730 2', 970,000 0.73 0.42 0.39 20,700 1,288 21 24.0 19,720 2,970,000 0.93 0.26 0.25 23,050 23,125 1,041 22 24.0 19,770 2,980,000 1.17 0.16 0.18 16,800 18,800 784 23 24.0 19,540 2,940,000 1.31 0.09 0.13 21,100 25,450 473 24 24.0 19,830 2,990,000 1.51 0.08 0.10 15,150 24,350 383 25 24.0 19,870 2,990,000 1.62 0.08 0.10 12,475 12,200 8,300 236 26 24.0 19,940 3,000,000 1.72 0.08 0.08 10,050 142 27 24.0 19,860 2,990,000 1.76 0.07 0.05 8,625 6,400 160 28 24.0 19,550 2,940,000 1.92 0.09 0.08 17,800 10,750 82 29 24.0 19,890 2,990,000 2.21 1.00 0.20 30 24.0 19,520 2,940,000 2.65 0.50 0.44 33,075 22,450 137 Totals, 645.1 525,510 79,110,000 Av'gs, 21.5 17,520 2,640,000 0.24 0.16 25,220 29,924 346 Notes:-Percentage of Bacteria removed, 98.63. * 3d Scraping; 0.05 feet removed, 691,820 gallons passed (104,190,000 per acre) since 2d Scraping. 132 REPORT OF RESIDENT ENGINEER,-SAND FILTERS. RECORD OF SAND FILTER No. 1, For the Month of December, 1897. Date. Hours Quantity in Gallons. Loss Turbidity. Bacteria Per Cubic Centimeter. 24 Hours in of Ending Opera- Rate of Head Gate Set- 9.00 A.M. tion. Total Filtration Efflu- Gate Settling Efflu- Passed. Per Acre Feet. Cham- thng ent. Chamber. Basin. ent. Daily. her. Basin. 1 24.0 20,170 3,040,000 3.17 0.26 0.25 36,000 20,000 130 2 24.0 19,920 3,000,000 3.39 0.24 0.22 23,300 21,350 196 3 24.0 20,110 3,030,000 3.63 0.16 0.16 17,900 15,550 201 4 24.0 19,880 2,990,000 3.72 0.09 0.10 17,250 14,200 140 5 24.0 19,900 3,000,000 3.86 0.07 0.08 11,450 9,450 143 6 24.0 20,030 3,020,000 4.05 0.21 0.13 7 24.0 19,980 3,010,000 4.11 0.36 0.10 28,850 16,925 126 8 22.5 17,000 2 730 000 2 560 000 4.21 0.33 0.15 24,400 28,350 85 9 1.7 * 1,140 2 400 000 20,050 31,300 10 24.0 18,890 2,850,000 0.99 0.14 0.15 21,100 33,200 643 11 24.0 17,760 2,670,000 2.35 25,700 46,600 307 12 24.0 19,580 2,950,000 2.71 0.10 0.12 8,025 17,400 231 13 24.0 20,650 3,110,000 2.34 0.09 0.09 16,400 14 24.0 20,050 3,020,000 1.31 0.09 0.08 7,800 11,325 ' 81 15 24.0 20,020 3,020,000 1.26 0.09 0.07 7,975 11,225 57 16 24.0 19,910 3,000,000 1.35 0.38 0.11 15,400 10,850 49 17 24.0 19,880 2,990,000 1.48 0.50 0.20 25,475 14,750 97 18 24.0 19,690 2,970,000 1.75 0.50 0.33 16,350 15,675 84 19 24.0 19,780 2,980,000 2.09 0.33 0.26 11,800 8,400 69 20 24.0 19,870 2,990,000 2.26 0.19 0.20 13,700 7,350 99 21 24.0 19,810 2,980,000 2.04 0.13 0.18 18,500 22 24.0 20,060 3,020,000 2.52 0.12 0.13 23 24.0 19,660 2,960,000 2 67 0.40 0.24 13,050 11,650 126 24 24.0 19,820 2,980,000 3.15 0.14 0.17 7,650 10,550 150 25 24.0 20,110 3,030,000 3.45 0.11 0.16 5,025 7,700 177 26 24.0 19,790 2,980 000 3.61 0.10 0.10 27 24.0 19,730 2 970,000 3.79 0.07 0.07 2,500 2,350 57 28 21.7 16,780 2 790 000 2 530 000 3.99 0.06 9.06 2,750 4,950 64 29 0.0 t o 0 0.06 0.05 1,900 5,050 93 30 23.4 19,000 2 930 000 0.35 0.06 0.05 4,000 3,950 265 31 24.0 19,900 3,000,000 0.35 0.05 0.04 3,900 4,325 398 Totals, 693.3 568,870 85,680,000 Av'gs, 22.4 18,350 2,760,000 0.19 0.14 14,433 14,923 163 i Notes:-Percentage of Bacteria removed, 98.87. *4th Scraping; 0.05 feet removed, 409,730 gallons passed (61,700,000 per acre) since 3d Scraping. f5th " 0.13 " " 372,980 " " (56,170,000 " " ) " 4th " TABULATION OF RESULTS. 133 RECORD OF SAND FILTER No. 1. For the Month of January, 1898. Date. 24 Hours Ending 9.00 A.M. Hours in Opera- tion. Quantity in Gallons. Loss of Head in Feet. Turbidity. Bacteria Per Cubic Centimeter. Total Passed. Rate of Filtration Per Acre Daily. Gate Cham- ber. Set- tling Basin. Efflu- ent. Gate Chamber. Settling Basin. Efflu- ent. 1 24.0 19,910 3,000,000 0.32 0.05 0.05 2,000 6,850 239 2 24.0 19,870 2,990,000 0.36 0.05 0.05 4,150 2,900 279 3 24.0 19,810 2,980,000 0.38 0.03 0.04 4 24.0 19,700 2,970^000 0.66 0.04 0.04 ...... 1,625 2,425 202 5 24.0 19,880 2,990,000 0.86 0.03 0.03 3,675 4,750 210 6 24.0 19,730 2,970,000 1.18 3,125 5,950 206 7 24.0 19,910 3,000,000 1 58 0.04 0.04 3,950 5,625 199 8 24.0 19,720 2,970,000 1.95 0.22 0.03 8,675 5,600 216 9 24.0 19,650 2,960,000 2.41 0.73 0.13 21,500 11,300 208 10 24.0 19,400 2,920,000 3.02 0.30 0.33 12,550 350 11 23.7 18,710 2 860 000 2 820 000 3.98 0.30 0.21 16,175 16,525 385 12 1.6 * 990 2 260 000 0.43 0.12 11,375 11,000 233 13 24.0 19,410 2,920,000 0.43 0.57 0.15 16,125 13,450 381 14 24.0 19,870 2,990,000 0.55 0.89 0.38 30,987 19,100 358 15 24.0 20,030 3,020,000 0.71 0.84 0.35 40,350 37,650 518 16 24.0 19,740 2,970,000 0.96 0.48 0.33 45,325 28,925 756 17 24.0 19,780 2,980,000 1.20 0.53 0.30 18 24.0 20,000 3,010,000 1.49 0.26 0.22 .074 21,275 32,875 510 19 24.0 19,740 2,970,000 1.62 0.20 0.19 .045 22,700 23,300 297 20 24.0 20,110 3,030,000 1.85 0.12 0.12 .045 11,000 15,650 252 21 24.0 19,830 2,990,000 1.98 0.16 0.10 .036 12,300 12,650 184 22 24.0 19,760 2,980,000 2.25 0.16 0.13 .023 19,000 13,900 119 23 24.0 19,790 2,980,000 2.46 0.19 0.14 .015 20,450 11,450 112 24 24.0 19,430 2,930,000 2.98 0.30 .015 23,750 17,000 211 25 24.0 17,020 2,560,000 4.16 0.50 .045 26.150 .297 26 0.6 t 420 2 400 000 60 000 0.19 .036 12,650 658 27 23.2 18,570 2 900 000 0.52 0.25 0.19 .011 15,000 15,550 561 28 24.0 19,790 2,980,000 0.80 0.22 0.19 .030 14,050 13,950 625 29 24.0 19,780 2,980,000 0.81 0.11 0.12 .030 6,825 10,400 478 30 24.0 19,990 3,010,000 1.04 0.08 0.09 2,600 6,925 299 31 24.0 19,660 2,960,000 1.26 0.09 0.08 Totals, 697.1 570,000 85,840,000 Av'gs, 22.5 18,390 2,770,000 0.27 0.15 15,333 13,828 334 Notes:-Percentage of Bacteria removed, 97.82. * 6th Scraping; 0.03 feet removed, 255.190 gallons passed; (38,430,000 per acre) since 5th Scraping. f 7th " 0.05 " " 255,500 " " (38,480,000 " ) " 6th " 134 REPORT OF RESIDENT ENGINEER,-SAND FILTERS. RECORD OF SAND FILTER No. 1, For the Month of February, 1898. Date. 24 Hours Ending 9.00 A.M. Hours in Opera- tion. Quantity in Gallons. Loss of Head in Feet. Turbidity. Bacteria Per Cubic Centimeier. Total Passed. Rate of Filtration Per Acre Daily. Gate Cham- ber. Set- tling Basin. Efflu- ent. Gate Chamber. Settling Basin. Efflu- ent. 1 24.0 19,820 2,980,000 1.55 0.08 0.07 .011 2,350 5,200 152 2 24.0 19,750 2,970,000 1.87 0.08 0.08 .003 2,250 3,975 91 3 24.0 19,670 2,960,000 2.20 0.09 0.08 2,775 4,050 128 4 24.0 19,760 2,980,000 2.59 0.06 0.08 .003 2,700 3,825 67 5 24.0 19,700 2,970,000 2.95 0.05 0.09 .003 1,575 5,075 87 6 24.0 19,610 2,950,000 3.44 0.05 0.04 .003 1,425 1,925 79 7 23.3 17,210 2 670 000 2 590 000 3.86 8 10.4 *7,610 20,570 2 650 000 1 150 000 0.04 0.03 1,700 1,775 9 24.0 3,100,000 0.31 0.04 0.03 3,550 3,700 119 10 24.0 20,340 3,060,000 0.30 0.14 0.04 .003 11 24.0 20,300 3,060,000 0.30 0.26 0.10 .001 12 24.0 20,280 3,050,000 0.31 0.30 0.16 .004 8,025 8,425 154 13 24.0 19,820 2,980,000 0.40 0.48 0.19 17,500 14,300 148 14 24.0 20,280 3,050,000 0.60 0.47 0.20 15 24.0 20,150 3,040,000 0.82 0.32 0.19 .023 25,600 33,600 710 16 24.0 19,880 2,990,000 0.90 0.25 0.19 .045 24,150 27,050 753 17 24.0 19,900 3,000,000 1.06 0.19 0.19 .030 23,600 29,000 932 18 24.0 20,290 3,060,000 1.21 0.13 0.14 .023 9,250 12,450 735 19 24.0 19,880 2,990,000 1.30 0.09 0.10 .023 11,025 13,575 458 20 24.0 19,730 2,970,000 1.45 0.08 0.07 .015 7,050 10,700 270 21 24.0 20,410 3,070,000 1.62 22 24.0 20,250 3,050,000 1.72 0.16 0.10 .010 12,025 11,375 133 23 24.0 20,140 3,030,000 1.85 0.15 0.12 .010 10,150 16,250 95 24 24.0 19,900 3,000,000 1.98 0.13 0.14 .010 12,350 10,350 96 25 24.0 19,900 3,000,000 2.10 0.11 0.13 9,400 14,800 111 26 24.0 19,820 2,980,000 2.11 0.08 0.08 .010 12,112 19,775 157 27 24.0 19,720 2,970,000 2.15 0.07 0.08 .015 7,750 13,775 103 28 24.0 19,850 2,990,000 2.22 0.05 0.06 8,600 Totals, 657.7 544,540 81,990,000 Av'gs, 23.5 19,450 2,930,000 ( 0.15 0.11 .013 9,430 12,043 266 Notes:-Percentage of Bacteria removed, 97.18. * 8th Scraping; 0.10 feet removed, 233,730 gallons passed (35,190,000 per acre) since 7th Scraping. TABULATION OF RESULTS. 135 RECORD OF SAND FILTER No. 1, For the Month of March, 1898. Date. 24 Hours Ending 9.00 A.M. Hours in Opera- tion. Quantity in Gallons. Loss of Head in Feet. Turbidity. Bacteria Per Cubic Centimeter. i Total Passed. Rate of Filtration Per Acre Daily. Gate Cham- ber. Set- tling Basin. Efflu- ent. Gate Chamber. Settling Basin. Effln. ent. 1 24.0 19,940 3,000,000 2.27 0.04 0.06 .010 6,125 13,825 122 2 24.0 19,840 2,990,000 2.35 0.05 0.06 .010 7,650 17,250 78 3 24.0 20,230 3,050,000 2.47 .010 7,450 13,625 65 4 24.0 20,060 3,020,000 2.56 6.05 0.05 .006 4,925 4,875 59 5 24.0 19,790 2,980,000 2.66 0.06 0.05 .010 4,475 4,725 55 6 24.0 19,120 2,880,000 2.73 0.07 0.05 .010 5,150 6,225 26 7 24.0 20,280 3,050,000 3.02 - 3,400 8 24.0 20,040 3,020,000 3.15 0.04 0.05 .004 5,100 7,350 38 9 24.0 20,010 3,010,000 3.19 0.05 0.05 .006 5,075 5,750 52 10 24.0 17,830 2,690,000 3.30 0.05 0.05 .010 5,175 6,425 40 11 8.4 *5,810 2 490 000 0.06 0.06 5,700 8,650 48 12 24.0 20,440 3,080,000 0.40 0.05 .001 5,475 115 13 24.0 20,520 3,090,000 0.32 0.05 0.06 6,525 8,300 70 14 24.0 20,470 3,080,000 0.37 0.08 0.08 15 24.0 20,450 3,080,000 0.30 0.12 0.06 .006 12 025 13,000 39 16 24.0 20,350 3,070,000 0.38 0.12 0.08 .006 14,175 15,100 115 17 24.0 20,170 3,040,000 0.39 0.11 0.09 .010 12,400 12,750 80 18 24.0 19,760 2,980,000 0.40 0.10 0.09 .010 7,350 9'900 43 19 24.0 20,220 3 050,000 0.44 0.09 0.09 .015 8,600 10,000 74 20 24.0 20,220 3,050,000 0.43 0.08 0.09 .006 9,900 6,250 47 21 24.0 20,050 3,020,000 0.46 0.49 0.09 .010 22 24.0 20,150 3,040,000 0.49 0.90 0.17 .010 23 24.0 20,020 3,020,000 0.58 1.00 0.50 .010 56,000 32,200 35 24 24.0 20,120 3,030,000 0.70 2.38 0.70 .045 55,483 30,717 62 25 24.0 19,870 2,990,000 0.90 0.90 0.80 .045 23,267 33,333 145 26 24.0 20,200 3,040,000 1.27 0.41 0.70 .066 14,400 21,500 229 27 24.0 19,830 2,990,000 1.52 0.20 0.19 .030 7,000 8,500 77 28 24.0 20,320 3,060,000 1.62 0.17 0.15 4,800 9,050 68 29 24.0 20,120 3,030,000 1.95 0.20 0.16 .004 4,750 7,316 94 30 24.0 19,870 2,990,000 1.97 0.29 0.18 .004 9,967 5,000 24 31 24.0 20,120 3,030,000 2.28 0.50 0.20 .010 16,583 9,400 28 Totals, 728.4 606,220 91,320,000 Av'gs, 23.5 19,560 2,950,000 0.30 0.18 .014 11,747 12,347 71 Notes:-Percentage of Bacteria removed, 99.40. * 9th Scraping; 0.07 feet removed, 606,430 gallons passed (91,320,000 per acre) since 8th Scraping. *270 gallons passed before and 5,540 gallons after Scraping. 136 REPORT OF RESIDENT ENGINEER,-SAND FILTERS. RECORD OF SAND FILTER No. 1, For the Month of April, 1898. Date. 24 Hours Ending 9.00 A.M. Hours in Opera- tion. Quantity in Gallons. Loss of Head in Feet. Turbidity. Bacteria Per Cubic Centimeter. Total Passed. Rate of Filtration Per Acre Daily. Gate Cham- ber. Set- ting Basin. Efflu- ent. Gate Chamber Settling Basin. Efflu- ent. 1 24.0 20,530 3,090,000 2.64 0.18 0.21 .006 8,500 6,900 50 2 24.0 20,200 3,040,000 2.69 0.17 0.24 .010 5,375 7,700 27 3 24.0 19,810 2,980,000 2.87 0.13 0.16 .010 5,287 7,850 21 4 24.0 20,470 3,080,000 3.20 0.11 0.13 3,667 7,450 26 5 24.0 20,040 3,020,000 3.33 0.08 0.11 .010 2,937 4*875 31 6 24.0 18,900 2,850,000 3.61 0.07 0.09 .003 2,512 3,875 28 7 6.2 * 3,530 2 050 000 530 000 0.07 0.09 .006 2,562 4,825 19 8 24.0 20,220 3,050,000 0.40 0.08 0.07 .003 1,725 4,627 58 9 24.0 20,590 3,100,000 0.28 0.07 0.06 .004 2,112 1,250 43 10 24.0 20,650 3,110,000 0.27 0.05 0.05 .006 2,925 3,350 31 11 24.0 20,440 3,080,000 0.29 0.04 0.05 2,917 2,400 31 12 24.0 20,330 3,060,000 0.45 0.04 0.06 .001 3,037 2,550 25 13 24.0 20,480 3,080,000 0.39 0.04 0.05 .001 3,575 2,975 31 14 24.0 20,150 3,040,000 0.47 0.04 0.04 .001 2,537 3,150 34 15 24.0 20,050 3,020,000 0.56 0.04 0.04 .001 2,980 2,650 33 16 24.0 20,050 3,020,000 3,030,000 0.61 0.04 0.04 .001 2,612 2,175 27 22 17 24.0 20,090 0.66 0.03 0.04 .001 1,525 2,025 18 24.0 20,040 3,020,000 0.68 0.06 0.04 2,317 1,350 39 19 24.0 20,000 3,010,000 0.70 0.05 0.04 2,525 2,300 30 32 20 24.0 19,850 2,990,000 0.77 0.04 0.04 .001 2,750 1,650 21 24.0 19,680 2,960,000 0.90 0.06 0.05 .001 2,162 1,575 22 99 24.0 20,250 3,050,000 1.09 0.05 0.05 .001 1,537 1,775 40 23 24.0 20,270 3,050,000 1.28 0.04 0.04 .001 1,425 1,150 24 24.0 20,040 3,020,000 1.40 0.04 0.04 .001 2,410 1,350 37 25 24.0 20,000 3,010,000 1.54 0.06 0.04 7,350 1,350 55 26 24.0 19,840 2,990,000 1.65 0.20 0.06 .001 16,000 7,150 26 28 27 24.0 20,250 3,050,000 1.89 0.23 0.12 .001 18,912 9,800 28 24.0 20,120 3,030,000 1.96 0.21 0.15 .001 17,725 11,225 25 29 24.0 20,000 3,010,000 2.07 0.12 0.11 .001 10,587 9,725 54 30 24.0 20,350 3,060,000 2.21 0.09 0.10 .003 7,812 7,925 44 - Totals, 702.2 587,220 88,430,000 ■ - - - - - - Av'gs, 23.4 19,570 2,950,000 0.08 0.08 .003 5,010 4,928 33 Notes:-Percentage of Bacteria removed, 99.34. * 10th Scraping; 0.12 feet removed, 531,790 gallons passed (80,100,000 per acre) since 9th Scraping. * 3030 gallons passed before and 500 gallons after Scraping. TABULATION of results. 137 RECORD OF SAND FILTER No. 1, For the Month of May, 1898. Date. 24 Hours Ending 9.00 A.M. Hours in Opera- tion. Quantity in Gallons. Loss of Head in Feet. Turbidity. Bacteria Per Cubic Centimeter. Total Passed. Rate of Filtration Per Acre Daily. Gate Cham- ber. Set- tling Basin. Efflu- ent. Gate Chamber. Settling Basin. Efflu- ent. 1 24.0 20,060 3,030,000 2.29 0.07 .003 5,490 5,250 46 2 24.0 20,240 3,050,000 2.31 0.05 0.06 4,380 4,600 60 3 24.0 19,990 3,010,000 2.35 0.03 0.04 .001 3,120 3,100 130 4 24.0 19,870 2,990,000 2.36 0.04 0.04 .001 4,090 2,050 53 5 24.0 20,000 3,010,000 2.44 0.05 0.04 .001 4,020 2,300 64 6 24.0 19,760 2,980,000 2.54 0.04 0.04 .001 3,350 1,420 46 7 24.0 20,150 3,040,000 2.71 0.04 0.04 .005 3,060 1,500 65 8 24.0 19 820 2,980,000 2.95 0.05 0.04 .002 4,720 2,100 88 9 24.0 19,790 2,980,000 3.25 0.17 0.04 13,500 4,400 55 10 24.0 19,010 2,860,000 3.79 0.28 0.14 .002 19,400 5,550 77 11 24.0 15,340 2,310,000 4.16 0.10 0.13 .008 8,100 9,600 68 12 11.7 * 8,000 2 480 000 2 1 0 000 0.05 0.09 .007 4,960 7,000 110 13 24.0 19,900 3,000,000 0.27 0.07 00.1 .007 4,310 4,950 84 14 24.0 20,040 3,020,000 0.26 0 04 0.08 .009 4,510 73 15 24.0 20,010 3,010,000 0.22 0.06 0.07 .007 7,400 3,800 78 16 24.0 20,010 3,010,000 0.23 0.10 0.08 7,050 3,650 125 17 24.0 20,060 3,020,000 0.22 0.20 0.06 .009 33,600 6,450 64 18 24.0 20,090 3,030,000 0.23 1.20 0.29 .013 55,000 16,600 51 19 24.0 20,030 3,020,000 0.25 0.40 0.55 .018 17,000 31,000 75 20 24.0 20,080 3,030,000 0.27 0.18 0.19 .025 12,500 12,700 108 21 24.0 20,050 3,020,000 0.29 0.18 0.11 .018 12,700 15,400 110 .22 24.0 19,970 3,010,000 0.31 0.55 0.13 .020 22,800 10,900 98 23 24.0 20,020 3,020,000 0.31 0.40 0.23 .018 13,200 9,000 160 24 24 0 20,030 3,020,000 0.35 0.15 0.15 .025 13,900 6,400 no 25 24.0 20,040 3,020,000 0.35 0.50 0.17 .022 19,500 5,100 250 26 24.0 19,980 3,010,000 0.35 0.31 0.21 .020 12,500 6,950 160 27 24.0 19,990 3,010,000 0.37 0.19 0.18 .018 6,400 7,450 245 28 24.0 19,950 3,000,000 0.38 0.11 0.13 .020 3,840 5,300 350 29 24.0 20,010 3,010,000 0.37 0.09 0.10 .022 3,410 3,720 190 30 24.0 19,960 3,010,000 0.38 0.10 0.08 .022 4,070 2,750 96 31 24.0 19,930 3,000,000 0.38 0.05 0.06 .022 1,500 2,250 no Totals, 731.7 602,180 90,710,000 Av'gs, 23.6 19,430 2,930,000 0.19 0.12 .012 10,800 6,770 no Notes;-Percentage of Bacteria removed, 98.98. * Uth Scraping; 0.07 feet removed, 679,270 gallons passed (102,300,000 per acre) since 10th Scraping. * 1,000 gallons passed before and 7,000 gallons after Scraping. 138 REPORT OF RESIDENT ENGINEER,-SAND FILTERS. RECORD OF SAND FILTER No. 1, For the Month of June, 1898. Date. 24 Hours Ending 9.00 A.M. Hours in Opera- tion. Quantity in Gallons. Loss of Head in Feet. Turbidity. Bacteria Per Cubic Centimeter. Total Passed. Rate of Filtration Per Acre Daily. Gate Cham- ber. Set- tling Basin. Efflu- ent. Gate Chamber. Settling Basin. Efflu- ent. 1 24.0 19,870 2,990,000 0.38 0.07 0.05 .018 1,960 1,800 87 2 24.0 20,230 3,050,000 0.46 0.04 0.04 .015 1,700 1,220 73 3 24.0 20,180 3,040,000 0.41 0.06 0.04 .020 1,420 1,370 90 4 24.0 20,150 3,040,000 0.49 0.04 0.03 .015 3,020 2,450 170 5 24.0 20,140 3,030,000 0.49 0.03 0.03 .018 2,300 1,150 100 6 24.0 20,060 3,020,000 0.54 0.02 0 03 3,540 2,050 205 7 24.0 20,010 3,010,000 0.60 0.02 0.03 .012 3,460 2,250 130 8 24.0 19,860 2,990,000 0.69 0.02 0.02 .012 12,000 5,900 235 9 24.0 20,150 3,040,000 0.96 0.02 0.02 .009 23,400 6,100 350 10 24.0 19,760 2,980,000 1.12 0.02 0.02 .007 17,400 10,100 130 11 24 0 20,420 3,070,000 1.56 0.02 0.02 28,300 11,400 195 12 24.0 19,510 2,940,000 2.15 0.02 0.02 .005 19,500 9,200 160 13 24.0 19,830 2,990,000 2.67 0.02 0.02 12,400 6,100 100 14 24.0 19,750 2,970,000 3.25 0.03 0.03 .005 21,200 5,500 92 15 24.0 15,070 2,270,000 4.16 0.70 0.20 .003 27,900 12,700 66 16 3.0 1,400 1 680 000 0.80 0.20 .001 16.500 11,000 80 17 9.2 *7,000 2 740 000 0.42 7,650 385 18 24.0 20,000 3,010,000 1 0.23 0.21 .010 4,250 560 19 24.0 19,910 3,000,000 0.21 0.15 0.17 .010 6,150 28,900 101 20 24.0 19,930 3,000,000 0.24 0.40 0.15 .013 5,300 75 21 24.0 19,930 3,000,000 ; 0.21 0.65 0.27 .015 25,100 12,600 75 22 24.0 20,390 3,070,000 0.27 0.70 0.50 .013 15,600 12,900 67 23 24.0 20,480 3,080,000 0.34 0.42 0.40 .010 5,950 8,150 77 24 24.0 . 20.330 3,060,000 0.39 0.23 0.29 .013 3,500 4,770 81 25 24.0 20,460 3,080,000 0.36 0.12 0.16 .023 2,700 4,980 3,150 80 26 24.0 19,950 3,000,000 0.44 0.12 0.10 .010 2,150 135 27 24.0 19,930 3,000,000 0.48 0.11 0.08 .010 43 28 24.0 19,880 2,990,000 0.55 Cl 07 0.07 .008 3,770 2,500 49 29 24.0 20,040 3,020,000 0.61 0.07 0.06 .008 6,250 4,120 45 30 24.0 19,980 3,010,000 0.68 0.06 0.06 .007 11,200 8,250 46 Totals, 684.2 564,600 85,010,000 Av'gs, 22.8 18,820 2,830,000 0.19 0.11 .011 11,100 5,930 135 Notes:-Percentage of Bacteria removed, 98.78. . * 12th Scraping; 0.07 feet removed, 683,540 gallons passed (102,970,000 per acre) since 11th Scraping. TABULATION OF RESULTS. 139 RECORD OF SAND FILTER No. 1, For the Month of July, 1898. Date. Hours Quantity in Gallons. Loss of , Head in Feet. Turbidity. Bacteria Per Cubic Centimeter. 24 Hours Ending in Opera- Rate of Gate Cham- ber. Set- tbng Basin. 9.00 A.M. tion. Total Passed. Filtration Per Acre Daily. Efflu- ent. Gate Chamber Settling Basin? Efflu- ent. 1 24.0 20 000 3,010,000 0.74 0.29 0.07 .002 6,000 4,750 33 2 24.0 19,880 2,990,000 0.80 0.22 0.12 .008 5,700 3,770 39 3 24.0 20,390 3,070,000 3,050,000 0.85 0.17 0.11 .008 5,250 2,700 71 4 24.0 20,250 1.01 0.11 0.09 4,150 4,600 115 5 24.0 20,280 3,050,000 1.17 0.09 0.09 3,150 3,000 47 6 24.0 19,900 3,000,000 1.35 0.05 0.06 6,850 1,370 45 7 24.0 19,800 2,980,000 1.54 0.05 0.06 .007 6,350 4,350 49 8 24.0 19,830 2,990,000 1.74 0.08 0.09 .007 5,650 4,200 36 9 24.0 20,120 3,030,000 1.92 0.05 0.04 .003 10,350 11,900 61 10 24.0 19,860 2,990,000 2.10 0.05 0.03 .002 8,100 10,250 6,100 78 11 24.0 19,680 2,960,000 2.20 0.04 0.04 47 12 24.0 19,430 2,930,000 2.25 0.04 0.03 .002 3,850 2,000 49 13 24.0 19,980 3,010,000 2.49 0.05 0.04 .001 19,800 6,400 39 14 24.0 19,620 2,950,000 2.80 0.04 0.04 .001 40,500 14,900 38 15 24.0 20,280 3,050,000 3.03 0.03 0.03 .001 40,200 27,900 65 16 24.0 19,980 3,010,000 3.31 0.08 0.06 .001 42,600 29,000 73 17 24.0 19,260 2,900,000 3.42 0.80 0.14 .005 41,000 38,800 82. 18 24.0 17,400 2,620,000 4.71 0.10 0.15 .001 35,200 26,400 64 19 8.7 * 6,760 2 810 000 0.06 0.13 14,400 18,100 290 20 24.0 20,420 3,080,000 0.23 0.07 0.13 .002 22,600 12,900 280 21 24.0 20,450 3,080,000 0.19 0.19 0.09 .002 24,500 15,200 67 22 24.0 20,490 3,090,000 0.19 0.11 0.10 .001 20,800 14,400 55 23 24.0 19,950 3,000,000 0.20 0.05 0.06 .000 15,200 20,200 58 24 24.0 19,710 2,970,000 0.18 0.03 0.05 .000 8,050 12,200 54 25 24.0 20 390 3,070,000 0.17 0.06 0.06 14,600 11,700 44 26 24.0 20,670 3,110,000 0.17 0.06 0.06 .001 8,750 11,500 43 27 24.0 19,800 2,980,000 0.19 0.09 0.12 .000 16,500 9,900 41 28 24.0 20,100 3,030,000 0.19 0.06 0.06 .000 24,500 28,200 14 29 24.0 20,100 3,030,000 0-20 0.05 0.05 .000 18,500 13,700 43 30 24.0 20,160 3,040 000 0.21 0.05 0.04 .005 17,700 15,600 95 31 24.0 20,100 3,030,000 0.22 0.06 0.06 .000 20,100 14,500 135 Totals, 728.7 605,040 91,120,000 Av'gs, 23.5 19,520 2,940,000 0.11 0.07 .002 16,800 13,000 74 Notes:-Percentage of Bacteria removed, 99.56. * 13th Scraping; 0.09 feet removed, 624,610 gallons passed (94,030,000 per acre) since 12th Scraping. * 460 gallons passed before and 6,300 gallons after Scraping. 140 REPORT OF RESIDENT ENGINEER,-SAND FILTERS. RECORD OF SAND FILTER No. 1, For the Month of August, 1S98. Date. 24 Hours Ending 5.00 A.M Hours in Opera- tion. Quantity in Gallons. Loss of Head in Feet. Turbidity. Bacteria Per Cubic Centimeter. Total Passed. Rate of Filtration Per Acre Daily. Gate Cham- ber. Set- tling Basin. Efflu- ent. Gate Chamber. Settling Basin. Efflu- ent. 1 24.0 19,620 2,950,000 0.21 0.42 0.14 48,200 26,100 72 2 24.0 19,740 2,970,000 0.24 0.70 0.50 .000 27,500 28,700 52 3 24.0 19.020 2,860,000 0.28 0.35 0.28 .000 20,200 14,400 28 4 24.0 20,550 3,090,000 0.32 0.15 0.17 .000 16,800 17,000 37 5 24.0 20,640 3,110,000 0.37 .000 22,300 12,500 25 6 24.0 20,580 3,100,000 0.44 0.80 0.45 .000 20,400 18,500 30 y 24.0 20,340 3,060,000 0.53 0.26 0.24 .000 9,300 15,100 44 8 24.0 20,310 3,060,000 0.65 0.37 0.16 .000 11,400 11,100 36 9 24.0 20,340 3,060,000 0.89 0.28 0.22 .000 49,400 11,100 85 10 24.0 19,470 2,930,000 1.27 0.92 0.75 .001 34,400 23,300 37 11 24.0 20,340 3,060,000 1.94 0.55 0.55 .006 18,700 20,400 31 12 24.0 19,980 3,010,000 2.20 0.38 0.46 .013 9,550 10,300 30 13 24.0 19,590 2,950,000 2.44 0.31 0.31 .013 8.850 8,200 28 14 24.0 20,460 3,080,000 2.76 0.60 0.42 .017 15,500 6,600 28 15 24.0 20,040 3,020,000 3.00 0.24 0.22 10,300 10,100 47 16 24.0 19,860 2,990,000 3.12 0.12 0.16 .007 4,800 4,150 40 17 24.0 19,740 2,970,000 3.26 0.15 0.15 .007 6,450 5,450 26 18 24.0 19,320 2,910,000 3.55 0.08 0.08 .013 7,300 7,000 45 19 23.6 17,560 2 680 000 2 640 000 3.90 0.10 0.09 .002 10,800 7,400 28 20 3.5 *2,270 2 330 000 340 000 0.30 0.07 27,300 3,520 37 21 24 0 19,920 3,000,000 0.25 1.75 0.50 .010 25,000 16,300 125 22 24.0 19,860 2,990,000 0.28 0.50 0.50 .0.7 22,700 11,100 135 23 24.0 20,010 3,010,000 0.32 0.31 0.22 .017 12,600 5,450 67 24 22.0 16,830 2 760 000 2 530 000 0.35 0.26 0.17 5,600 4,900 88 25 11.0 $9,020 2 970 000 1 360 000 0.18 0.11 .020 6,450 5,800 50 26 24.0 20,220 3,050,000 3,040,000 3,040,000 0.21 0.10 0.09 .017 1,920 3,100 72 27 24.0 20,160 0.19 0.09 0.08 .015 3,500 2,670 58 28 24.0 20,160 0.21 0.18 0.13 .010 5,020 2,320 42 29 24.0 20,100 3,030,000 0.23 0.10 0.08 3,020 2,800 47 30 24.0 20,160 3,040,000 0.25 0.09 0.08 .610 1,700 1,600 52 31 24.0 20,100 3,030,000 0.27 0.09 0.07 .010 1,520 1,150 74 Totals, 708.1 586,310 88,280,000 Av'gs, 22.8 18,910 2,850,000 0.36 0.25 .008 15,100 10,250 51 Notes:-Percentage of Bacteria removed, 99.G6. * 14th Scraping; 0.13 feet removed, 626,140 gallons passed (94,280,000 per acre) since 13th Scraping. § 15th " 0.05 " " 78,890 " " (11,870,000 " ) " 14th TABULATION OF RESULTS. 141 RECORD OF SAND FILTER No. 2, For the Month of July, 1897. Date. Hours Quantity in Gallons. Loss of 1 Head 1 in i Feet. Turbidity. Bacteria Per Cubic Centimeter. 24 Hours Ending 9.00 A.M. iu Opera- tion. Total Passed. Rate of Filtration Per Acre Daily. Gate Cham- ber. Set- tling Basin. Efflu- ent. Gate Chamber. Settling Basin. Efflu- ent. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 20.0 24.0 22.7 18.0 24.0 24.0 24.0 24.0 11,000 13,000 12,200 9,500 12,840 13,040 12,460 13,010 2 020 000 1 680 000 1,980,000 2 000 000 1 860 000 1 930 000 1 450 000 1,960,000 1,980,000 1,900,000 1,980,000 0.11 0.37 0.54 0.83 0.87 1.26 0.50 0.52 0.57 0.52 0.40 8,260 2,400 1,300 3,850 4,200 3,250 3,900 8,820 1,450 1,450 1,100 1,300 250 90 Totals, 180.7 97,050 14,790,000 Av'gs, 22.6 12,130 1,850,000 0.50 3,880 2,066 Notes:-Percentage of Bacteria removed, 46.8. The rates of filtration for Filter No. 2 were computed by dividing the "Total Passed" by 0.00656. This figure represents the area of the sand surface, calculated from the preliminary measure- ments of the basin and gives rates slightly in error. These results, at first about two per cent, too large, gradually changed to about two per cent, too small for the last month of the experiments, due to the fact that the area decreased as sand was removed by scraping. Where two numbers are given for a certain date in the "Rate" column, the upper one gives the rate of filtration for the actual time in operation. The lower figure gives the rate for twenty-four hours and has been used in computing the total for the month. 142 REPORT OF RESIDENT ENGINEER,-SAND FILTERS. RECORD OF SAND FILTER No. 2, For the Month of August, 1897. Pate. Quantity in Gallons. Loss of Turbidity. Bacteria Per Cubic Centimeter. Hours 24 Hours in Kliding Opera- Rate of Head Gate Cham- ber. •9.00 A.M. tion. Total Passed. Filtration Per Acre Daily. Feet. Set- tling Basin. Efflu- ent. / Gate Chamber. Settling Basin. Effllb ent. 1 24.0 13,080 1,990,000 1.57 0.22 7,250 2 24.0 12,400 710 1,890,000 1.75 0.11 3 5.3 500 000 1 1 0 0 0 0 1.30 0.09 725 66 4 15.4 * 1,540 358 000 230 000 0.08 900 58 5 22.2 7,840 1 300 000 1 200 000 0.09 0.08 675 92 50 6 24.0 14,050 2,140,000 0.19 0.10 750 7 24.0 11,920 1,800,000 0.19 825 16 8 24.0 14,100 2,150,000 0.31 0.07 625 25 9 24.0 13,700 2,090,000 0.30 0.10 10 24.0 13,500 2,060,000 0.37 0.08 625 34 11 24.0 13,460 2,050,000 0.46 0.06 575 12 12 24.0 13,380 2,040,000 0.77 0.80 4,075 59 13 24.0 13,230 2,020,000 1,970,000 1.02 14 24.0 12,920 1.35 1.00 4,400 15 24.0 13,280 2,020,000 1.66 0.21 1,875 '41 16 24.0 18,960 2,890,000 2.25 0.16 17 24.0 20,020 3,050,000 2.89 0.15 2,150 44 18 24.0 19,000 2,900,000 3.16 6,250 30 19 24.0 19,390 2,960,000 4.07 0.12 2,075 22 42 20 22.0 9,730 1 610 000 1 48 0 .0 00 5.59 0.17 6,400 21 19.5 g 15,940 2 990 000 2 430 000 2,200 88 22 24.0 19,670 3,000,000 0.30 Zd 24.0 19,400 2,960,000 2,930,000 0.38 0.12 1,300 81 24 24.0 19,260 0.36 0.08 500 28 25 24.0 19,350 2,950,000 0.38 1,150 36 26 24.0 19,760 3,010,000 0.40 1,300 38 27 24.0 19,440 2,970,000 0.45 1,325 18 12 28 24.0 20,050 3,060,000 0.42 975 29 24.0 19,430 2,970,000 0.44 0.08 950 28 30 24.0 19,670 3,000,000 0.32 31 24.0 19,610 2,990,000 0.26 0.02 2,362 17 Totals, 708.4 467,790 71,310,000 Av'gs, 22.9 15,090 2,300,000 0.19 2,089 42 Notes:-Percentage of Bacteria removed, 97.99. * 1st Scraping; 0.03 feet removed, 123,190 gallons passed (18,780,000 per acre) since beginning g 2d " 0.04 " " 230,020 " " (35,050,000 " ) " 1st Scraping. TABULATION OF RESULTS. 143 RECORD OF SAND FILTER No. 2, For the Month of September, 1897. Date. 24 Hours Ending 9.00 A.M. Hours in Opera-1 tion. | Quantity in Gallons. Loss of Head in Feet. Turbidity. Bacteria Per Cubic Centimeier. Total Passed. Rate of Filtration Per Acre Daily. Gate Cham- ber. Set- tling Basin. Efflu- ent. Gate Chamber. Settling Basin. Efflu- ent. 1 24.0 19,750 3,010,000 0.49 0.02 1,225 7 2 24.0 19,650 3,000,000 0.53 0.05 3,050 16 3 24.0 19,910 3,030,000 0.67 0.09 3,075 47 4 24.0 19,660 3,000,000 0.66 0.04 2,536 11 5 24.0 19,700 3,000,000 0.67 0.04 2,125 7 6 24.0 19,510 2,970,000 0.52 0.04 7 24.0 19,730 3,010,000 0.73 1,550 ii 8 24 0 19,700 3,000,000 0.79 0.04 2,400 7 9 24.0 19,770 3,010,000 0.89 0.05 26 10 24.0 19,710 3,000,000 1.00 4,538 9 11 24.0 19,680 3,000,000 1.05 0.03 1,613 ..... 9 12 24.0 19,770 3,010,000 0.79 ...... 625 7 13 24.0 19,680 3,000,000 0.73 0.04 14 24.0 19,660 3,000 000 0.50 4,950 7 15 24.0 19,540 2,980,000 0.57 0.03 1,545 4 16 24.0 18,960 2,890,000 0 68 0.04 1,593 5 17 21.0 19,790 3,020 000 0.73 0.04 1,650 27 18 24.0 19,730 3,010,000 1.15 0.07 2,170 27 19 24.0 19,570 2,980,000 1.29 0.05 1,900 18 20 24.0 19,540 2,9b0,000 1.54 3,225 18 21 24.0 19,680 3,000,000 1.88 0.05 1,225 13 22 24.0 20,010 3,050,000 2.31 0.09 • 700 7 23 24 0 20,030 3,050,000 2.78 0.04 2,275 19 24 24.0 19,700 3,000,000 3.00 0.05 3,125 41 25 24.0 19,730 3,010,000 3.35 0.05 2,250 44 26 24.0 19,830 3,020,000 3.75 0.05 9,575 10 27 24.0 19,370 2,950,000 3.86 28 24.0 19,810 3,020,000 5.07 1,750 7 29 24.0 19,800 3,020,n00 5. *5 0.06 1,667 12 30 24.0 19,550 2,980,000 6.56 0.07 2,100 25 Totals, 720.0 590,520 90,000,000 Av'gs, 24.0 19,680 3,000,000 0.05 2,478 16 Note:-Percentage of Bacteria removed, 99.35. 144 REPORT OF RESIDENT ENGINEER,-SAND FILTERS. RECORD OF SAND FILTER No. 2, For the Month of October, 1897. Date. 24 Hours Ending 9.00 A.M. Hours in Opera- tion. Quantity in Gallons. Loss of Head in Feet. Turbidity. Bacteria Per Cubic Centimeter. Total Passed. Rate of Filtration Per Acre Daily. Gate Cham- ber. Set- tling Basin. Efflu- ent. Gate Chamber. Settling Basin. Efflu- ent. 1 24.0 10,830 1,650,000 7.03 0.08 4,549 10 2 15.4 *12,650 3 000 000 0.06 5,525 132 3 24.0 19,700 3,000,000 0.28 0.05 5,625 130 4 24.0 19,030 3,040,000 0.30 5 24.0 20,120 3,070,000 0.30 6.05 3,362 21 6 24.0 19,840 3,020,000 0.32 0.05 1,876 19 7 24.0 20,060 3,060,000 0.34 0.04 18,550 10 8 24.0 20,160 3,060,000 0.39 0.04 17,363 18 9 24.0 19,230 2,930,000 0.43 0.03 62,325 15 10 x 24.0 20,080 3,060,000 0.46 0.03 20,550 13 11 24.0 20,120 3,070,000 0.54 0.03 22,575 12 24.0 19,940 3,040,000 0.57 0.03 13,700 12 13 24.0 19,790 3,020,000 0.58 0.03 14,675 13 14 24.0 19,580 2,980,000 0.61 0.03 17,150 21 15 24.0 19,870 3,030,000 0.76 0.03 27,300 16 16 24.0 20,030 3,050.000 0.82 0.03 19,950 33 17 24.0 19,910 3,030,000 0.87 0.03 29,750 15 18 24.0 19,910 3,030,000 0.95 0.03 19 24.0 19,700 3,000,000 1.07 76,913 18 20 24.0 19,590 2,990,000 1.12 0.03 93,450 19 21 24.0 19 970 3,040,000 1.30 0.03 99,600 24 22 24.0 19,820 3,020,000 1.44 0.03 159,500 22 23 24.0 19,840 3,020,000 1.58 0.03 151,250 26 24 24.0 19,730 3,010,000 1.70 0.03 196,500 18 25 24.0 19,990 3,050,000 1.80 0.03 26 24.0 19,650 3,000,000 1.92 0.03 94,500 25 27 24.0 19,870 3,030,000 2.09 0.03 118,500 34 28 24.0 19,650 2,990,000 2.11 0.03 155.000 25 29 24.0 20,170 3,070,000 2.28 0.02 206,500 26 30 24.0 19,880 3,030,000 2.26 0.02 183,750 124 31 24.0 19,860 3,020,000 2.51 220,300 38 Totals, 735.4 599,470 91,340,000 ... Av'gs, 23.7 19,340 2,950,000 0.04 72,878 32 Notes:-Percentage of Bacteria removed, 99.96. * 3rd Scraping; 0.04 feet removed, 812,930 gallons passed (123,920,000 per acre) since 2nd Scraping. TABULATION OF RESULTS. 145 RECORD OF SAND FILTER No. 2, For the Month of November, 1897. Date. 24 Hours Ending 9.00 A.M. Hours in Opera- tion. Quantity in Gallons. Loss of Head in Feet. Turbidity. Bacteria Per Cubic Centimeter. Total Passed. Rate of Filtration Per Acre Daily. Gate Cham- ber. Set- tling Basin. Efflu- ent. Gate Chamber. Settling Basin. Efflu- ent. 1 24.0 19,840 3,020,000 2.72 0.03 2 24.0 20,020 3,050,000 2.95 0.03 111,000 40 3 24.0 19,870 3,030,000 3.01 0.06 173 4 24.0 19,650 3,000,000 3.10 0.04 66,475 202 5 24.0 19,660 3,000,000 3.24 0.04 72,875 49 6 24.0 19,750 3,010,000 3.37 0.05 27,000 36 7 24.0 19,550 2,980,000 3.62 0.06 16,063 150 8 24.0 19,400 2,960,000 3.96 0.04 9 24.0 19,740 3,010,000 4.34 0.04 7,850 242 10 24.0 19,400 2,960,000 4.81 0.16 8,550 98 11 24.0 19,360 2,950,000 5.57 0.08 ...... 6,375 73 12 24.0 17,740 2,700,000 6.33 0.11 13 24.0 11,210 1,710,000 6.98 0.23 6,500 132 14 5.7 * 3,370 2 150 000 510 000 8,100 44 15 1.2 600 1 800 000 90 000 ...... 16 0.0 0 0 • 17 0.0 0 0 0.70 21,350 474 18 20.6 15,170 2 690 000 0.34 1.00 29,900 1,624 19 24.0 19,410 2,960,000 0.80 0.88 17,950 5,479 20 24.0 19,130 2,920,000 1.76 0.42 21,950 1,393 21 24.0 19,550 2,980,000 2.85 0.26 23,050 1,187 ' 22 24.0 19,600 2,990,000 3.89 0.16 16,800 1,032 23 24.0 17,570 2,680,000 4.94 0.09 21,100 580 24 0.0 § o 0 5.95 0.08 • 15,150 214 25 23.2 17,200 2 710 000 0.22 0.08 12,475 512 26 24.0 19,850 3,020,000 0.39 0.08 10,050 434 27 24.0 19,870 3,030,000 0.37 0.07 •••••• 8,625 297 28' 24.0 19,840 3,020,000 0.40 0.09 17,800 192 29 - 24.0 19,540 2,980,000 0.56 1.00 ...... 30 24.0 19,730 3,010,000 1.06 0.50 33,075 511 Totals, 602.7 475,620 72,500,000 Av'gs, 20.1 15,850 2,420,000 0.24 25,220 632 Notes:-Percentage of Bacteria removed, 97.49. *4th Scraping: 0.06 feet removed, 837,200 gallons passed (127,580,000 per acre) since 3d Scraping g 5th " 0.07 " " 111,030 " " ( 16,930,000 " ) " 4th 146 REPORT OF RESIDENT ENGINEER,-SAND FILTERS. RECORD OF SAND FILTER No. 2, For the Month of December, 1897. Date. 24 Hours Ending 9.00 A.M. Hours in Opera- tion. Quantity in Gallons. Loss Of Head in Feet. Turbidity. Bacteria Per Cubic Centimeter. Total Passed. Rate of Filtration Per Acre Daily.. Gate Cham- ber. Set- tling Basin. Efflu- ent. Gate Chamber. Settling Basin. Efflu- ent. 1 24.0 19,360 2,950,000 1.77 0.26 36,000 567 2 24.0 19,700 3,000,000 2.24 0.24 23,300 471 3 24.0 19,790 3,020,000 2.76 0.16 17,900 340 4 24 0 19,750 3,010,000 3.15 0.09 17,250 ... .. 243 5 24.0 19,700 3,000,000 3.57 0.07 11,450 226 6 24.0 19,460 2,970,000 4.12 0.21 y 24.0 17,490 2,670,000 4.79 0.36 28,850 144 8 24.0 15,900 2,420,000 6.11 0.33 24,400 125 9 24.0 18,700 2,850,000 5.77 20,050 242 10 24.0 11,500 1,750,000 6.36 0.14 21,100 180 11 9.0 *2,220 900 000 340 000 25,700 474 12 24.0 18,850 2,870,000 0.45 0.10 8,025 350 13 24.0 19,990 3,050,000 0.44 0.09 16,400 224 14 24.0 19,930 3,040,000 0.41 0.09 7,800 145 15 24.0 19,820 3,020,000 0.44 0.09 7,975 90 16 24.0 19,790 3,020,000 0.52 0.38 15,400 132 17 24.0 19,990 3,050,000 0.76 0.50 25,475 231 18 24.0 19,870 3,030,000 1.19 0.50 16,350 211 19 24.0 19,600 2,990,000 1.59 0.33 11,800 54 20 24.0 13,120 2,000,000 1.51 0.19 0.20 13,700 7,350 139 21 24.0 13,150 2,000,000 1.77 0.13 0.18 18,500 22 24 0 13,160 2,010,000 1.85 0.12 0.13 23 24.0 13,140 2,000,000 1.97 0.40 0.24 13,050 11,650 129 24 24.0 13,400 2,040,000 2.23 0.14 0.17 7,650 10,550 135 25 24.0 13,220 2,020,000 2.41 0.11 0.16 5,025 7,700 144 26 24.0 13,040 1,990,000 2.56 0.10 0.10 27 24.0 13,300 2,030,000 2.67 0.07 0.07 2,500 2,350 132 28 24.0 13,240 2,020,000 2.80 0.06 0.06 2,750 4,950 192 29 24.0 13,160 2,010,000 2.99 0 06 0.05 1,900 5,050 234 30 24.0 13,350 2,030,000 3.21 0.06 0.05 4,000 3,950 4,325 347 31 24.0 13,220 2,020,000 3.41 0.05 0.04 3,900 179 Totals, 729.0 499,910 76,220,000 Av'gs, 23.5 16,130 2,460,000 0 19 14,433 225 Notes:-Percentage of Bacteria removed, 98.44. * 6th Scraping; 0.09 feet removed, 299,600 gallons passed (45,660,000 per acre) since 5th Scraping. TABULATION OF RESULTS. 147 RECORD OF SAND FILTER No. 2, For the Month of January, 1898. Date. 24 Hours Ending 9.00 A.M. Hours in Opera- tion. Quantity in Gallons. Loss of Head in Feet. Turbidity. Bacteria Per Cubic Centimeter. Total Passed. Rate of Filtration Per Acre Daily. Gate Cham- ber. Set- tling Basin. Efflu- ent. Gate Chamber. Settling Basin. Efflu- ent. 1 24.0 12,970 1,980,000 3.52 0.05 0.05 2,000 6,850 210 2 24.0 12,080 1,840,000 3.91 0.05 0.05 4,150 2,900 121 3 4.2 * 2,080 1 830 000 0.03 0.04 4 24.0 13,040 1,990,000 0.26 0.04 0.04 1,625 2,425 352 5 24.0 13,300 2,030,000 0.20 0.03 0.03 3,675 4,750 263 6 24.0 13,240 2,020,000 0 23 3,125 5,950 336 7 24.0 13,200 2,010,000 0.25 0.04 0.04 3,950 5,625 286 8 24.0 12,890 1,960,000 0.30 0.22 0.03 8,675 5,600 320 9 24.0 13,370 2,040,000 0.40 0.73 0.13 21,500 11,300 369 10 24.0 12,870 1,960,000 0.66 0.30 0.33 12,550 427 11. 24.0 13,400 2,040,000 0.93 0.30 0.21 16,175 16,525 449 12 24.0 13,300 2,030,000 1.25 0.43 0.12 11,375 11,000 441 13 24.0 13,140 2,000,000 1.65 0.57 0.15 16,125 13,450 297 14 24.0 13,360 2,040,000 2.05 0.89 0.38 30,987 19,100 180 15 24.0 13,120 2,000,000 2.42 0.84 0.35 40,350 37,650 159 16 24.0 13,160 2,010 000 2.89 0.48 0 33 45,325 28,925 309 17 24.0 13,260 2,020,000 3.21 0.53 0.30 18 24.0 13,060 1,990,000 3.47 0.26 0.22 .015 21,275 32,875 366 19 24.0 13,080 1,990,000 3.72 0.20 0.19 .011 22,700 23,300 242 20 24.0 12,080 1,840,000 3.86 0.12 0.12 .015 11,000 15,650 208 21 5.2 § 2,640 1 850 000 320 000 4.87 0.16 0.10 .030 12,300 12,650 190 22 24.0 13,110 2,000,000 0.40 0.16 0.13 .023 19,000 13,900 250 23 24.0 13,270 2,020,000 0.47 0.19 0.14 .023 20,450 11,450 417 24 24.0 13,010 1,980,000 0.71 0.30 .023 23,750 17,000 457 25 24.0 13,020 1,990,000 1.36 0.50 .045 26,150 613 26 24.0 13,170 2,010,000 1.93 0.19 .036 12,650 478 27 24.0 13,160 2,010,000 2.56 0.25 0.19 .015 15,000 15,550 236 28 24.0 13,020 1,990,000 2.87 0.22 0.19 .015 14,050 13,950 307 39 24.0 13,090 2,000,000 3.25 0.11 0.12 .015 6,825 10,400 234 30 24.0 12,590 1,920,000 3.62 0.08 0.09 2,600 6,925 160 31 24.0 10,350 1,580,000 3.91 0.09 0.08 Totals, 705.4 380,430 58,010,000 Av'gs, 22.8 12,270 1,870,000 0.28 0.15 .022 15,333 13,828 310 Notes:-Percentage of Bacteria removed, 97.98. *7th Scraping; 0.05 feet removed, 341,950 gallons passed (52,150,000 per acre) since 6th Scraping, g 8th " 0.04 " " 226,030 " " (34,450,000 " ) " 7th " * 560 gallons passed before and 1,520 gallons after scraping. g 1,640 " " " " 1,000 " " " 148 REPORT OF RESIDENT ENGINEER,-SAND FILTERS. RECORD OF SAND FILTER No. 2, For the Month of February, 1898. Date. 24 Hours Ending 9.00 A.M. Hours in Opera- tion. Quantity in Gallons. Loss of Head in Feet. Turbidity. Bacteria Per Cubic Centimeter. Total Passed. Rate of Filtration Per Acre Daily. Gate Cham- ber. Set- tling Basin. Efflu- ent. Gate Chamber. Settling Basin. Efflu- ent. 1 5.9 *2,640 1 630 000 400 000 5.70 0.08 0.07 .011 2,350 5,200 317 2 24.0 13,070 1,990,000 0.23 0.08 0.08 .003 2,250 3,975 3 24.0 13,200 2,010,000 0.22 0.09 0.08 2,775 2,700 4,050 123 4 24.0 13,190 2,010,000 0.20 0.06 0.08 .006 3,825 131 5 24.0 13,230 2,020,000 0.26 0.05 0.09 .006 1,575 5,075 112 6 24.0 13,270 2,020,000 2,040,000 0.30 0.05 0.04 .006 1,425 1,925 229 7 24.0 13,400 0.29 1,700 1,775 118 8 24.0 13,300 2,030,000 0.31 0.04 0 03 9 24.0 13,230 2,020.000 0.39 0.04 0.03 3,550 3,700 113 10 24.0 13,550 2,060,000 0.48 0.14 0.04 .003 11 24.0 13,360 2,040,000 0.55 0.26 0.10 .004 8,425 12 24 0 13,300 2,030,000 0.65 0.30 0.16 .004 8.025 177 13 24.0 13,120 2,000,000 0.79 0.48 0.19 17,500 14,300 144 14 24.0 13,400 2,040,000 1.05 0.47 0.20 25,600 33,600 15 24.0 13,420 2,050,000 1.26 0.32 0.19 .015 511 16 24.0 13',240 2,020,000 1.35 0.25 0.19 .030 24,150 27,050 617 17 24.0 13,290 2,030,000 1.46 0.19 0.19 .023 23,600 29,000 18 24.0 13,440 2,050,000 1.55 0.13 0.14 .015 9,250 12,450 441 19 24.0 13,560 2,070,000 1.58 0.09 0.10 .023 11,025 13,575 415 20 24.0 13350 2,050,000 1.69 0.08 0.07 .015 7,050 10,700 428 21 24.0 20,000 3,050,000 2.02 .015 12,025 307 22 24.0 20,380 3,110,000 2.24 0.16 23 24.0 19,970 3,040,000 2.45 0.15 .015 10,150 321 24 24.0 20,390 3,110,000 2.67 0.13 .010 12,350 162 25 24.0 20,190 3,080,000 2.87 0.11 9,400 25(1 26 24.0 20,050 3,060,000 2.92 0.08 .015 12,112 314 27 24.0 19,990 3,050,000 3.00 0.07 .015 7,750 272 28 24.0 19,960 3,040,000 3.15 0.05 8,600 Totals, 653.9 416,590 63,520,000 Av'gs, 23.4 14,880 2,270,000 0.15 .012 9,430 275 Notes:-Percentage of Bacteria removed, 97.08. * 9th Scraping; 0.10 feet removed, 131,430 gallons passed (20,0.10,000 per acre) since 8th Scraping TABULATION OF RESULTS. 149 RECORD OF SAND FILTER No. 2, For the Month of March, 1898. Date. 24 Hours Ending 9.00 A.M. Hours in Opera- tion. Quantity in Gallons. Loss of Head in Feet. Turbidity. Bacteria Per Cubic Centimeter. Total Passed. Rate of Filtration Per Acre Daily. Gate Cham- ber. Set- tling Basin. Efflu- ent. Gate Chamber. Settling Basin. Efflu- ent. 1 24.0 20,560 3,130,000 3.23 0.04 .010 6,125 201 2 23.6 18,330 2 840 000 2 790 000 3.49 0.05 .006 7,650 167 3 10.0 * 6,640 2 420 000 .003 7,450 4 24.0 20,360 3,100,000 0.36 0.05 ...... .003 4,925 589 5 24.0 20,300 3,090,000 0.31 0.06 .010 4,475 86 6 24.0 20,260 3,090,000 0.30 0.07 .010 5,150 75 7 24.0 20,360 3,100,000 0.33 ...... 3,400 8 24.0 20,130 3,070,000 0.39 0.04 .006 5,100 81 9 24.0 20,400 3,110,000 3,080,000 0.48 0.05 .006 5,075 105 10 24.0 20,220 0.64 0.05 .010 5,175 217 11 24.0 19,880 3,030,000 0.85 0.06 5,700 130 12 24.0 20,220 3,080,000 1.09 0.05 .003 5,475 157 13 24.0 20,040 3,050,000 1.24 0.05 .015 6,525 107 14 24.0 19,960 3,040,000 1.44 0.08 15 24.0 19,800 3,020,000 1.54 0.12 .015 12,025 109 16 24.0 20,160 3,070,000 1.65 0.12 .015 14,175 203 17 24.0 19,910 3,030,000 1.69 0.11 .010 12,400 272 18 24.0 20,090 3,060,000 1.77 0.10 .015 7,350 252 19 24.0 20.510 3,130,000 1.94 0.09 .015 8,600 103 20 24.0 19.790 3,020,000 2.09 0.08 .006 9,900 165 21 24.0 19,110 2,910,000 2.52 0.49 .010 22 24.0 19,720 3,010,000 3.86 0.90 .022 23 15.2 t 8,900 2 150 000 1.00 .015 56,000 • 1,120 24 24.0 19,880 3,030,000 0.49 2.38 .030 55,483 1,391 25 24.0 19,800 3,020,000 1.32 0.90 .099 23,267 1,192 26 24.0 19,650 2,990,000 2.34 0.41 .055 14,400 479 27 24.0 19,270 2,940,000 3.31 0.20 .032 7,000 227 28 21.6 14,900 2 520 000 2 270 000 4.36 0.17 4,800 205 29 9.0 t 6,360 2 590 000 970 000 3,080,000 0.20 4,750 30 24.0 20,200 0.30 0.29 .015 9,967 169 31 24.0 20,140 3,070,000 0.33 0.50 .030 16,583 491 Totals, 703.4 575,850 87,750,000 Av'gs, 22.7 18,580 2,830,000 0.30 .018 11,747 332 Notes:-Percentage of Bacteria removed, 97.11. * 10th Scraping; 0.06 feet removed, 452,810 gallons passed (69,040,000 per acre) since 9th Scraping. 111th " 0.06 " " 389,830 " " (59,400,000 " ) " 10th " j 12th " 0.13 " " 100,430 " " (15,310,000 " ) " 11th " f 1,970 gallons passed before and 6,930 gallons after scraping. 150 REPORT OF RESIDENT ENGINEER,-SAND FILTERS. RECORD OF SAND FILTER No. 2, For the Month of April, 1898. Date. 24 Hours Ending 9.00 A.M. Hours in Opera- tion. Quantity in Gallons. Loss of Head in Feet. Turbidity. Bacteria Per Cubic Centimeter. Total Passed. Rate of Filtration Per Acre Daily. Gate Cham- ber. Set- tling Basin. Efflu- ent. Gate Chamber. Settling Basin. Efflu- ent. 1 24.0 19,850 3,020,000 0.43 0.18 .036 8,500 300 2 24.0 19,720 3,010,000 0.60 0.17 .022 5,375 153 3 24.0 20,030 3,050,000 0.79 0.13 .015 5,287 153 4 24.0 20,080 3,060,000 1.02 0.11 3,667 127 5 24.0 20,020 3,050,000 1.28 0.08 .015 2,937 116 6 24.0 20,270 3,090,000 1.59 0.07 .006 2,512 80 7 24.0 20,070 3,060,000 1.94 0.07 .006 2,562 89 8 24.0 20,110 3,070,000 2.25 0.08 .003 1,725 91 9 24.0 19,510 2,980,000 2.74 0.07 .003 2,112 75 10 24.0 19,970 3,040,000 3.26 0.05 .001 2,925 82 11 24.0 20,200 3,080,000 3.64 0.04 2,917 80 12 24.0 17,130 2,610,000 3.97 0.04 .001 3,037 81 13 10.2 * 7,830 2 800 000 0.04 .001 3,575 77 14 24.0 20,170 3,080,000 0.30 0.04 .001 2,537 84 15 24.0 20 290 3,090,000 0.35 0.04 .001 2,980 88 16 24.0 20,420 3,110,000 027 0.04 .001 2,612 61 17 24.0 20,350 3,100,000 0 27 0.03 .003 1,525 104 18 24.0 20,340 3,100,000 0 25 0.06 2,317 213 19 24.0 20.260 3,090,000 0.32 0.05 2,525 64 20 24.0 20,580 3.140,000 0.35 0.04 .001 2,750 58 21 24.0 20,690 3,150,000 0.37 0.06 .001 2,162 46 22 24.0 20,570 3,140,000 3,020,000 0.42 0.05 .001 1,537 37 23 24.0 19,820 0.46 0.04 .001 1,425 29 24 24.0 20,050 3,0(10,000 0.50 0.04 .001 2.410 67 25 24.0 19,960 3,040.000 0.53 0.06 7,350 90 26 24.0 19,890 3,030,000 0.55 0.20 .001 16,000 46 27 24.0 20.260 3,090,000 0.8L 0.23 .001 18,912 77 28 24.0 20,370 3,110,000 0.96 0.21 .002 17,725 78 29 24.0 20,030 3,050,000 1.14 0.12 .004 10,587 48 30 24.0 20,120 3,070,000 1.30 0.09 .003 7,812 43 Totals, 706.2 588,960 89,780,000 Av'gs, 23.5 19,630 2,990,000 0.08 .005 5,010 91 Notes : -Percentage of Bacteria removed, 98.18. * 13th Scraping; 0.07 feet removed, 283,930 gallons passed (43,830,000 per acre) since 12th Scraping, * 270 gallons passed before, and 7,560 gallons after scraping. TABULATION OF RESULTS. 151 RECORD OF SAND FILTER No. 2, For the Month of May, 1898. Date. 24 Hours Ending 9.00 A.M. Hours in Opera- tion. Quantity in Gallons. Loss of Head in Feet. Turbidity. Bacteria Per Cubic Centimeter. Total Passed. Rate of Filtration Per Acre Daily. Gate Cham- ber. Set- tling Basin. Efflu- ent. Gate Chamber. Settling Basin. Efflu- ent. 1 24.0 19,970 3,040,000 1.40 .003 5,490 45 2 24.0 19,890 3,030,000 1.50 0.05 4,380 106 24.0 19,740 3,010,000 1.60 0.03 .001 3,120 50 4 24.0 20,120 3,070,000 1.80 0.04 .001 4,090 47 5 24.0 20,180 3,080,000 1.96 0.05 .000 4,020 145 6 24.0 20,450 3,120,000 2.12 0.04 .000 3,350 30 7 24.0 20,030 3,050,000 2.28 0.04 .005 3,060 32 8 24.0 19,720 3,010,000 2.51 0.05 .003 4,720 23 9 24.0 19,210 2,930,000 2.91 0.17 13,500 35 10 24.0 13,820 2,100,000 4.03 0.28 .006 19,400 41 11 12.1 * 8,500 2 580 000 0.10 .010 8,100 68 12 24.0 20,000 3,050,000 0.24 0.05 .009 4,960 75 13 24.0 20,020 3,050,000 0.22 0.07 .009 4,310 63 14 24.0 20,020 3,050,000 0.22 0.04 .009 4,510 63 15 24.0 20,030 3,050,000 0.20 0.06 .009 7,400 93 16 24.0 20,090 3,060,000 0.21 0.10 7,050 165 17 24.0 20,050 3,060,000 0.23 0 20 .007 33,600 180 18 24.0 20,020 3,050,000 0.34 1.20 .019 55,000 195 19 24.0 19,790 3,020,000 0.59 0.40 .022 17,000 195 20 24 0 20,440 3,120,000 0.69 0.18 .028 12,500 260 21 24.0 19,450 2,970,000 0.82 0.18 .018 12,700 230 22 24.0 19,780 3,010,000 1.04 0.55 .018 22,800 325 23 24.0 20,080 3,060,000 1.37 0.40 .020 13,200 70 24 24.0 19,940 3,040,000 1.51 0.15 .028 13,900 '71 25 24.0 19,680 3,000,000 1.76 0.50 .022 19,500 69 26 24.0 19,900 3,030,000 2.05 0.31 .020 12,500 67 27 24.0 20,090 3,060,000 2.30 0.19 .015 6,400 59 28 24.0 19,780 3,010,000 2.49 0.11 .018 3,840 54 29 24.0 19,820 3,020,000 2.61 0.09 .015 3,410 98 30 24.0 19,930 3,040,000 3.06 0.10 .015 4,070 60 31 24.0 20,060 3,060,000 3.01 0.05 .013 1,500 49 Totals, 732.1 600,600 91,550,000 Av'gs, 23.6 19,370 2,950,000 0.19 0.12 10,800 99 Notes:-Percentage of Bacteria removed, 99.03. *14th Scraping; 0.07 feet removed, 545,360 gallons passed (83,140,000 per acre) since 13th Scraping. *500 gallons passed before and 8,000 gallons after scraping. 152 REPORT OF RESIDENT ENGINEER,-SAND FILTERS RECORD OF SAND FILTER No. 2, For the Month of June, 1898. Date. 24 Hours Ending 9.00 A.M. Hours in Opera- tion. Quantity in Gallons. Loss of Head in Feet. Turbidity. Bacteria Per Cubic Centimeter. Total Passed. Rate of Filtration Per Acre Daily. Gate Cham- ber. Set- tling Basin. Efflu- ent. Gate Chamber. Settling Basin. Efflu- ent. 1 24.0 20,350 3,100,000 2.94 0.07 .015 1.960 44 2 24.0 20,200 3,080,000 2 85 0.04 .010 1,700 ...... 37 3 24.0 19,540 2,980,000 3.24 0.06 .015 1,420 58 4 24.0 16,190 2,470,000 3.90 0.04 .012 3,020 66 5 5.9 * 2,700 1 888 ' 0.03 .012 2,300 83 6 24.0 20,000 3,050,000 0.30 0.02 3,540 105 7 24.0 20,150 3,070,000 0.23 0.02 .009 3,460 120 8 24.0 20,250 3,090,000 0.20 0.02 .009 12,000 190 9 24.0 19,880 3,030,000 0.18 0.02 .008 23,400 90 10 24.0 19,890 3,030,000 0.19 0 02 .007 17,400 68 11 24.0 19,950 3,040,000 0.18 0.02 28,300 68 12 24.0 19,880 3,030,000 0.16 0.02 .005 19,500 80 13 24.0 20,380 3,110,000 0.17 0.02 12,400 73 14 24.9 20,150 3,070,000 0.15 0.03 .005 21,200 52 15 24.0 19,720 3,010,000 0.29 0.70 .002 27,900 57 16 24.0 19,370 2,950,000 0.55 0.80 .007 16,500 104 17 24.0 20,060 3,060,000 0.82 0.42 .010 7 650 68 18 24.0 19,460 2,970,000 1.01 0.21 .010 4,250 55 19 24.0 20,020 3,050,000 1.38 0.15 .007 6,150 45 20 24.0 19,700 3,000,000 2,600,000 1.90 0.40 .013 28,900 21 24.0 17,060 3.23 0.65 .022 25,100 38 22 8.9 g 6,500 2 068 888 0.70 .018 15,600 93 23 24.0 20,020 3,050,000 0.25 0.42 .025 5,950 100 £4 24.0 20,060 3,060.000 0.24 0.23 .025 3 500 73 25 24.0 20,220 3,080,000 0.20 0.12 .025 2,700 58 26 24.0 20.000 3,050.000 0.21 0.12 .013 4,980 58 27 24.0 20,080 3,060,000 0.20 0.11 .015 63 28 24.0 19,940 3,040,000 0.23 0.07 .013 3 770 76 29 24.0 19,940 3,040 000 0.24 0.07 .012 6,250 66 30 24.0 19,920 3,030,000 0.30 0.06 .010 11,200 (>0 Totals, 686.8 561,580 85,600,000 • Av'gs, 22.9 18,720 2,850,000 0.19 .012 11,100 72 Notes:-Percentage of Bacteria removed, 99.35. * 15th Scraping; 0.10 feet removed, 484 950 gallons passed (73,920,000 per acre) since 14th Scraping, § 16th " 0.11 " " 317,620 " " (48,420,000 " ) " 15th * 1,700 gallons passed before and 1,000 gallons after scraping. g 700 u .. .. .< 5)800 TABULATION OF RESULTS. 153 RECORD OF SAND FILTER No. 2, For the Month of July, 1898. Date. 24 Hours Ending 41.00 A.M. Hours in Opera- tion. Quantity in Gallons. Loss of Head in Feet. Turbidity. Bacteria Per Cubic Centimeter. Total Passed. Rate of Filtration Per Acre Daily. Gate Cham- ber. Set- tling Basin. Efflu- ent. Gate Chamber. Settling Basin. Efflu- ent. 1 24.0 33,390 5,090,000 0.60 0.29 0.07 .002 6,000 4,750 47 2 24.0 33,090 5,040,000 0.78 0.22 0.12 .010 5,700 3,770 57 3 24.0 32,480 4,950,000 0.99 0.17 0.11 .012 5,250 2,700 46 4 24.0 33,600 5,120,000 1.30 0.11 0.09 4,150 4,600 59 5 24.0 33,300 5,080,000 1.62 0.09 0.09 3,150 3,000 76 6 24.0 32,850 5,010,000 2.07 0 05 0 06 6,850 1,370 110 7 24.0 32,800 5,000,000 2.52 0.05 0.06 .007 6,350 4,350 55 8 24.0 33,500 5,110,000 3.07 0.08 0.09 .007 5,650 4,200 50 9 20.6 24,000 4 260 000 3 660 000 3.75 0.05 0.04 .005 10,350 11,900 65 10 13.6 *18,130 4 870 000 0.05 0.03 8,100 6,100 500 11 24.0 33,580 5,120,000 0.42 0.04 0.04 10,250 295 12 24.0 33,980 5,180,000 0.37 0.04 0.03 .002 3,850 2,000 104 13 24.0 33,830 5,160,000 0.35 0.05 0.04 .001 19,800 6,400 65 14 24.0 33,900 5,170,000 0.31 0.04 0.04 .001 40,500 14,900 119 15 24 0 34,000 5,180,000 0.32 0.03 0.03 .001 40,200 27,900 166 16 24.0 34,000 5,180,000 0.32 0.08 0.06 .001 42,600 29,000 140 17 24.0 33 650 5,130,000 0.33 0.80 0.14 .007 41,000 38,800 99 18 24.0 33 900 5,170,000 0.37 0.10 0.15 .001 35,200 26,400 66 19 24.0 33,700 5,140,000 0.39 0.06 0.13 .000 14,400 18,100 57 20 24.0 33,480 5,100,000 0.42 0.07 0.13 .003 22,600 12,900 42 21 24.0 33,280 5,070,000 0.45 0.19 0.09 .002 24,500 15,200 37 22 24.0 33,750 5,140,000 0.53 0.11 0.10 .001 20,800 14,400 51 23 24.0 33,570 5,120,000 0.59 0.05 0.06 .000 15,200 20,200 62 24 24.0 33,100 5,050,000 0.64 0.03 0.05 .000 8,050 12,200 56 25 24.0 32.850 5,010,000 0.89 0.06 0,06 14,600 11,700 48 26 21.0 33,550 5,110,000 0.99 0.06 0.06 .001 8,750 11,500 62 27 24.0 33,100 5,050,000 1.34 0.09 0.12 .000 16,500 9,900 49 28 24.0 33,400 5,090,000 1.60 0.06 0.06 .000 24,500 28,200 39 29 24.0 33,000 5,030,000 1.84 0.05 0.05 .000 18,500 13,700 43 30 24 0 32,850 5,010,000 2.19 0.05 0.04 .005 17,700 15,600 68 31 24.0 32,600 4,970.000 2.54 0.06 0.06 .000 20,100 14,500 35 Totals, 730.2 1,010,210 154,000,000 Av'gs, 23.6 32,590 4,970,000 i 0.11 0.07 .002 16,800 13,000 89 Notes:-Percentage of Bacteria removed, 99.47. * 17th Scraping; 0.06 feet removed, 454,990 gallons passed (69,350,000 per acre) since 16th Scraping. 154 REPORT OF RESIDENT ENGINEER,-SAND FILTERS. RECORD OF SAND FILTER No. 2, For the Month of August, 1898. Date. Hours Quantity in Gallons. Loss of Head in Feet. Turbidity. Bacteria Per Cubic Centimeter. 24 Hours Ending in Opera- Rate of Gate Cham- ber. Set- tling Basin. 9.00 A.M. tion. Total Passed. Filtration Per Acre Daily. Efflu- ent. Gate Chamber. Settling Basin. Efflu- ent. 1 24.0 32,100 4,890,000 3.20 0.42 0.14 48,200 26,100 35 2 24.0 1 24,800 3,780,000 4.13 0.70 0.50 .000 27,500 28,700 55 Q 12.4 *15,600 4610 000 0.35 0.28 20,200 14,400 96 4 24.0 33,700 5,140,000 5,150,000 0.37 0.15 0.17 .000 16,800 17,000 145 5 24.0 33,800 0.34 .000 22,300 12,500 60 6 24.0 33,900 5,170,000 0.34 0.80 0.45 .001 20,400 18,500 49 7 24.0 ! 33,700 5,140,000 0.37 0.26 0.24 .000 9,300 15,100 37 8 24.0 ! 33,600 5,120,000 0.42 0.37 0.16 .000 11,400 11,100 60 9 24.0 33,500 5,110,000 0.52 0.28 0.22 .000 49,400 11,100 44 10 24.0 33,300 5,080,000 0.65 0.92 0.75 .004 34,400 23,300 77 11 24.0 33,500 5,110,000 0.86 0.55 0.55 .025 18,700 20,400 130 12 24.0 33,000 5,030,000 1.04 0.38 0.46 .025 9,550 10,300 59 13 24.0 33,500 5,110,000 1.26 0.31 0.31 .025 8,850 8,200 69 14 24.0 33,000 5,030,000 1.51 0.60 0.42 .027 15,500 6,600 48 15 24.0 33,700 5,140,000 1.80 0.24 0.22 10,300 10,100 57 16 24.0 33,600 5,120,000 1.96 0.12 0.16 .023 4,800 4,150 50 17 24.0 33,500 5,110,000 2.16 0.15 0.15 .020 6,450 5,450 7,000 48 18 24.0 33,000 5,030,000 2.45 0.08 0.08 .017 7,300 58 19 24.0 33,300 5,080,000 2.74 0.10 0.09 .011 10,800 27,300 7,400 67 20 23.5 30,900 4810 000 2.99 0.30 0.07 .010 3,520 77 21 23.7 26,800 4 140 000 4 090 000 3.95 1.75 0.50 .010 25,000 16,300 54 22 9.5 §12,700 4 900 000 1940 000 0.50 0.50 22,700 11,100 225 23 24.0 33,500 5,110,000 0.48 0.31 0.22 .075 12,600 5,450 240 24 24.0 33,400 5,090,000 0.43 0.26 0.17 .055 5,600 4,900 125 25 24.0 33,400 5,090,000 0.45 0.18 0.11 .025 6,450 5,800 110 26 24.0 33,300 5,080,000 0.43 0.10 0.09 .020 1,920 3,100 77 27 24.0 33,200 5,060,000 0.45 0.09 0.08 .017 3,500 2,670 85 28 24.0 33,000 5,030,000 0.53 0.18 0.13 .017 5,020 2,320 78 29 24.0 33,700 5,140,000 0.60 0.10 0.08 3,020 1,700 2,800 85 30 24 0 33,700 5,140,000 0.69 0.09 0.08 .015 1,600 74 31 24.0 33,600 5,120,000 0.76 0.09 0.07 .015 1,520 1,150 69 Totals, 717.1 979,300 149,320,000 Av'gs, 23.1 31,600 4,820,000 0.36 0.25 .017 15,100 10,250 82 Notes:-Percentage of Bacteria removed, 99.46. *18th Scraping; 0.07 feet removed, 778,950 gallons passed (118,740,000 per acre) since 17th Scraping, g 19th " 0.12 " " 608,050 " " ( 92,720,000 " ) " 18th " * 850 gallons passed before and 14,750 gallons after scraping. WARREN FILTER EXPERIMENTS. 155 CHAPTER HI. Warren Filter Experiments. Description. A complete sectional plan and elevation of the Warren Filter used in these experiments will be found on Plates No. 15 and No. 16, opposite page 156. In the description many things will be mentioned, which are common to both the Warren and Jewell Filter Systems ; and, in order to save repetition, they will be described in sufficient detail here and simply noted in Chapter IV.* The water was supplied from the six-inch main in the center of the building, through a four-inch pipe, which entered at one end of the set- tling basin; the coagulant was also introduced at this same point. After leaving the settling basin, the water passed to the filter through an eight- inch pipe under the filter tank, and up through a central well over the filter bed. After passing down through the filter bed, the water was collected in troughs underneath, which were covered with perforated screens. From these troughs the water flowed to an iron stand pipe out- side the filter, in which was placed a so-called automatic weir. From the weir the water passed out through a six-inch meter into the effluent tank under the floor. Wash water was pumped to the filter, when required, through a four-inch line leading to the effluent pipe, and, after passing up through the sand, overflowed down through angular gutters and out through a waste pipe at the opposite side of the filter. Settling Basin. The settling basin was an eliptical wooden tank, having an area of 176 square feet and a capacity of 13,200 gallons; or equal to the flow for forty minutes with the filter running at the rate of 120,000,000 gallons per acre daily. The basin was divided into four parts by baffle walls, and the distance from the inlet to the outlet, along the center line of flow, was about 36 feet. Displacement was not complete, however and changes in the character of the applied water were quite often noticed at the outlet much sooner than the time above mentioned. The outlet con- sisted of a vertical box, two and one-half square feet in area and extending from the bottom to within two feet of the top of the basin. All water passed down through this box to the exit pipe. In the bottom, near the outlet, there was a flap valve for the removal of mud and sediment. The entering water passed through a four-inch meter; then thiough a butterfly valve, connected with a float, which by regulating the supply, controlled the water level in the basin and filter. The water then passed through an eight-blade propeller wheel, six inches in diameter. This propeller revolved with a speed in proportion to the rate of flow of the *The relation of the Warren Filter System to other apparatus is shown upon Plate No. 13, opposite Page 116. 156 REPORT OF RESIDENT ENGINEER,-WARREN FILTER. entering water. Connection was made through a vertical shaft with bevelled gears, to operate a modified form of tympanum, or pump, made of vulcanized rubber. Coagulant. The inner end of each arm of the pump was connected to one of a series of six tubes, placed in the hub and parallel to the shaft. The inside diameter of each arm was half an inch. This pump revolved in a tank, which was kept full of the solution of sulphate of alumina, and each arm, in turn, was filled with the solution. Later in the revolution, this flowed down into the hub and out into a lead cup on the side of the tank. From this cup a lead pipe carried the solution down into the settling basin. The quantity of the coagulant was varied, either by changing the strength of the solution, or by inserting stoppers in some of the arms of the pump. The sulphate of alumina was dissolved in water in tubs, holding 390 gallons each, placed on top of the settling basin, and the solution was always thoroughly mixed before being used. These tubs were connected by brass piping with the tank in which the pump was placed, and the solution was allowed to flow from one tank at a time. The elevation of the solution in the pump tank was kept as constant as possible by rubber float valves. It was found, however, that this method was not entirely satisfactory, as the rubber valves frequently became clogged. When a new solution was first used, the higher eleva- tion of the solution in the pump tank, due to the pressure from a full tub, caused very much more coagulant to be added to the applied water than when the solution in the upper tub had nearly run out. To offset this trouble, the valve from the upper tub was opened a little only at the beginning, and this opening was gradually increased as the tub became emptied. Even in this way, the application of the coagulant solution was not constant; the effect of which will be shown by the tables presented under the discussion of, " Variations in the Rate of Filtration and in the Application of Coagulant." There was a scale upon each coagulant tub, graduated in percentages of the full capacity. The records show the amount of coagulant dissolved and the percentage of a full tub remaining unused at various times, from which the exact amount used during any given period was calculated. Filter. The filter had an effective sand area of 118 square feet and was com- posed of a circular wooden tank resting upon timbers, which were placed upon the floor of the buiding. On the bottom of the inside of the tank there were placed radial iron troughs, set in concrete, which served as a support for a brass strainer floor, and also as collectors for the filtered P late No. 15. CITY OF PITTSBURGH FILTRATION COMMISSION PLAN OF WARREN FILTER P late No. 16. CITY OF PITTSBURGH FILTRATION COMMISSION ELEVATION OF WARREN FILTER DESCRIPTION. 157 water. Under the bottom of the tank and connected directly with the eight-inch inlet pipe, there was a central well, 1.50 feet in diameter inside, which extended up through the floor 0.77 foot above the sand surface. Connected with this central well and between the collecting troughs, there were ten two-inch horizontal pipes, which connected with iron gutters, or vertical troughs, placed around the circumference of the filter inside the staves. The inlet water to the filter was distributed over the sand surface from the central well, and from the circumferential gutters. The sand used was crushed quartz, which was angular at first, but the sharp edges became rounded after some months of use. The effective size was 0.63 m. m.; and the uniformity coefficient, I. I. The sand, which was 2.3 feet deep, rested directly upon the brass strainers, or screens, which were composed of perforated plates fastened to the radial iron troughs. There were ten of these radial plates and each had about 292,900 holes, each hole being 0.024 inch in diameter. There were twenty holes to each inch, in a radial direction, and ten in a line at right angles to this. The whole exit system, therefore, comprised a total area of 9.2 square feet. The flow from one-quarter of the holes was obstructed, as they were directly over the ribs of the troughs, and the net exit area was estimated to be 7.1 square feet. The total exit area of the radial troughs was 0.87 square foot. In addition to this last area, there were small screens, each two inches in diameter, placed around the central well; the total area of which was 0.02 square foot. From the troughs, the water drained into a central annular compartment, of 1.13 square feet in area, from which the water passed, through an eight-inch pipe, to the chamber of the automatic weir. The water rose to a level in this chamber, dependent upon the loss of head, caused by the clogging of the filter, and passed down through an inside center pipe and out to a six-inch meter, which registered all the water passing through the filter. Outside of the pipe, placed inside of the weir chamber, there was a sliding pipe, which was attached at the top to a copper float; thereby maintaining an approximately constant head upon the orifice in the pipe. By this means, it was intended to deliver a constant quantity, whatever the loss of head. In fact, however, the quantities filtered were somewhat greater shortly after washing, than before. This is explained at a greater length under the head of " Variations in the Rate of Filtration, and in the Application of Coagulant. Washing. Filtered water was furnished to this filter for washing purposes, and also to the Jewell Filter, by two duplex steam pumps, size 12x7 x 18. These pumps drew water from the large tank, under the building, which received the effluents from the two filters. The wash water passed through a four-inch meter and then entered the filter through the effluent pipe, 158 REPORT OF RESIDENT ENGINEER,-WARREN FILTER. passing up through the perforated screens and sand in the opposite direc- tion to that of the current of water when filtering. As the dirty water flooded above the sand, it overflowed down through the central well and annular gutters, from which it passed out through the eight-inch pipe, by which the settled water entered, and into the sewer. Agitator. The agitator consisted of two horizontal arms, connected to a central vertical shaft, upon each of which were nine teeth, each tooth being three feet long. When the agitator was placed in the lowest position, the bot- tom of the rakes just cleared the strainer floor by 0.14 foot. The agitator was raised and lowered by means of a hydraulic lift, supported by I beams, placed upon the top of the filter. Power was given to this lift from the water supply system through a three-way cock, placed upon the side of the filter. These I beams also supported the proper pulley and gears which transmitted power to the rakes. Power was supplied to the pulley by a belt from the main shafting. Power to the shafting was given by a small 6-inch x 8|-inch engine, placed upon the floor, which was sup- plied with steam at 100 pounds pressure, and which ran at 300 revolutions per minute. The rake system made about three revolutions per minute. General. When the Warren Filter and settling basin were first filled with water they leaked very badly, and, a sewer trench under the building being open at the time, the sills of the building settled in places under the filter. The settlement amounted to about two inches on one side, and, in order that the operations of the filter should not be in any way dis- turbed, the floor timbers were levelled up. It was found necessary to allow an abundance of air to enter the top of the central pipe of the automatic weir, to prevent a vacuum being formed and thus cause the float and orifice to drop, causing too much water to flow. The entrance of the air, however, caused serious over- registration of the meter upon the effluent pipe; the error occasioned in this way reaching thirteen per cent. After a trial of various devices, vents were arranged which reduced this error to four per cent. Before the reducing pressure valve was placed upon the inlet water system, upon February 17, 1898, many of the rubber discs to the four- inch inlet meters were broken; also many of those used in the wash meters were broken. Later, brass discs were used in both places and no further trouble of this kind was experienced. The service upon the wash lines was quite severe, the meters being placed at a short distance from the pumps, and frequently the pins and rollers were broken. The Pittsburgh Meter Company deserves special mention for its zealous interest and efforts in meeting these difficult conditions. COMPOSITION OF COAGULANT. 159 Operations. In addition to the records taken to determine the amount of inlet, wash, and effluent waters, and the amount of coagulant applied, it was provided in the record books that the exact time of the various items of operation should be entered and the loss of head observed at frequent intervals. The latter, which was allowed to reach a limit of five feet before washing, was determined by the difference between the heights of water in two glass gage tubes; one of which was connected with the water on the surface of the filter and the other with the effluent pipe before the automatic weir. The records taken at 9.00 A. M. served as a basis of the calculations of the day's work, but all the observations were also made at 3.00 P. M., 9.00 P. M., and 3.00 A. M. Special records, taken at times of washing, served as a basis of calculation in regard to this important detail. There were frequent interruptions in the operations during the first two weeks, in fact, it was January 29, 1897, before the filter was run during the night. Delays in the operations are noted upon the monthly record sheets in the proper places. COMPOSITION OF COAGULANT. The sulphate of alumina used during the experiments, with both the Warren and Jewell Filters, had the following composition, as de- termined from frequent analyses. Analysis of Sulphate of Alumina Used in the Experiments. Table A. Calendar Date of Collection, 1898. Aluminum Oxide, Soluble in Water. Parts by Weight. -X Insoluble in Water. Iron Oxide. Sulphuric Acid. January 22 16.96 0.00 38-95 0.12 3i 16.96 0.00 38.51 O.36 February 17-32 0.00 39.18 0.13 March 30 16.7O 0.00 37-84 O.42 April 16.68 0.00 38.85 0.10 17.00 0.00 37.90 0.25 16.52 0.00 35-49 0.15 May 3 16.88 0.00 37-96 0.30 23 17-04 0.00 37-67 0.25 17.22 0.00 38.00 0.20 30 16.94 0.00 39-30 0.26 June 9 17.28 0.00 39-70 O.l8 20 17-40 0.00 38.54 O.I4 July 2 I7-9O 0.00 39.60 o-35 13 I9.O4 0.00 39-29 0.13 26 18.84 0.00 39-56 0.20 August 4 I7-64 0.00 39-09 0.26 12 I5-76 0.00 40.59 0-37 20 I5-92 0.00 38.57 0.40 Averages, I7.l8 0.00 38.66 0.24 160 REPORT OF RESIDENT ENGINEER,-WARREN FILTERS. VARIATIONS IN THE RATE OF FILTRATION AND IN THE APPLICATION OF COAGULANT. In carrying on the experiments it was soon noticed that the quantity of water filtered was not always the same; that it was frequently greatest directly after a washing and gradually diminished when the filter became clogged, as the time for another washing approached. Tests were con- ducted occasionally with the special object of ascertaining the facts, as to whether or not the filter was wholly automatic in action, and as to whether the weir regulated accurately the quantities of water filtered. The information in Table B shows the results of one of these tests, which is taken as representing average conditions. It may be noted here that until July 13, 1898, a 300,000 gallon orifice ring was used in the weir. For the first few months the quantity of effluent was maintained at about this quantity. During the month of June, however, there was a noticeable decrease in the quantity, and upon July 13, a 350,000 gallon ring was placed in the weir, which remained until the close of the experiments. It was also noticed that the effluent from this filter frequently became turbid, when the character of the applied water had not changed, and while the coagulant solution remained of the same strength. Regarding this, it was noticed that, when a new solution of sulphate of alumina was first used, greater quantities were administered to the water in the set- tling basin, due to the great head from the pipe leading to the pump tank. Tests were also conducted, sometimes in connection with those previously mentioned, to furnish information about this feature. The results of representative tests are given; in Table B, compared with the quantity of water filtered, and in Tables C, D, and E, com- pared with the estimated amount of sulphate of alumina used, computed from the decrease in alkalinity. Table B also shows the number of bacteria in the samples, collected many times during the test. Table B. Special Test with the Warren Filter. Variations in the Rate of Filtration and in the Application of Coagulant, For the 24. Hours Ending 9.00 A. M., April 15, 1898. Sulphate of Alumina Bacteria Per For the Efil uent Used. Cubic Centimeter. 30 Minutes Quantity, Total Grains Per Applied Effluent. Ending, Gallons. Pounds. Gallon. Water. 9.30 A. M. 7,890 O.65 O.58 3^50 • • • 10.00 " 7350 o-55 0-49 4,550 86 10.30 " 7,610 o-55 0.51 • • • 11.00 " 7,210 0-45 0-44 • • • 11-30 " 7,170 0.40 o-39 • • . 12.00 M. 7,170 0.40 o-39 3,750 104 VARIATION IN RATE OF FILTRATION. 161 For the Effluent Sulphate of Alumina Used. Bacteria Per Cubic Centimeter. 30 Minutes Quantity, Total Grains Per Applied Effluent. Ending, Gallons. Pounds. Gallon. W ater. 12.30 P. M. 7,210 0.45 0-44 • • • I.OO 7,210 o-55 o-53 2,200 82 I-3O 7,220 0-45 0-44 2.00 7,240 o-59 0-57 3,100 122 2.30 7,170 0.58 0-57 3-00 7P5O 0.56 0.56 2,000 54 3-20 CC Valve Closed for Washing. 3-30 4,630 0.42 0.63 340 Valve Opened after Washing. 4.00 5,5io 0.46 0.58 2,850 62 4-30 Ci 8,670 0.60 0.48 5-oo 8,670 0-55 0-44 2,700 36 5-30 8,530 0.51 0.42 6.00 Ci 8,530 0.98 0.80 3,850 57 6.30 8,410 o-77 0.64 7.00 8,440 0.63 0.52 2,100 50 7-30 cc 8,340 0.66 0-55 8.00 8,390 0.66 0-55 3,050 43 8.30 8,340 0.65 o-55 9.00 8,240 0.63 ' 0.54 3,150 63 9-30 8,230 0.65 o-55 10.00 8,110 0.61 0.52 2,300 4i T0.30 8,070 0.58 0.50 11.00 7,9io 0.60 o-53 2,500 5o 11.30 Mid. 7,880 o-57 0.51 12.00 7,700 o-55 0.50 2,750 60 12.30 A. M. 7,550 0.56 0.52 1.00 7,7oo 0-54 0.49 3,450 67 1-30 7,440 0.64 0.60 2.00 cc 7,400 0.85 0.80 2,750 74 2.30 7,330 0-95 0.91 3-oo Ci 7,600 o-73 0.67 2,450 55 3-30 7,320 0.56 0-54 4.00 7450 0.62 0.58 2,750 84 4-30 6,810 0-55 0.52 5-oo 6,940 0.50 0.50 3,000 54 5-30 6,790 0-55 0-57 6.00 6,670 0.51 0-54 2,300 66 6.30 Ci 6,780 0-47 0-49 7.00 CC 6,760 0-57 o-59 3,300 206 7-30 CC 6,890 0-55 0.56 8.00 cc 6,840 0-54 0-55 3,100 136 8.30 cc 6,740 0.48 0.50 9.00 cc 6,380 0-45 0-49 3,550 62 TABLE B.-Continued. Notes :- Changed from Coagulant Tub No. 2 to Coagulant Tub No. 1, at 5.35 P. M., April 14, 1898. Changed from Coagulant Tub No. 1 to Coagulant Tub No. 2, at 1.19 A. M., April 15, 1898, 162 REPORT OF RESIDENT ENGINEER,-WARREN FILTER. Table C. Special Test with the Warren Filter, Variation in the Application of Coagulant, From 9.00 A. M. to 10.23 P. M., June 10, 1898. Time. Effluent Quantity, Gallons Between Observa- tions. Alkalinity of Effluent, in Terms of Calcium Car- bonate, Parts Per 100,000. Sulphate of Alumina Used. Pounds Between Observa- tions. Grains Per Gallon, by Weight, Between Observations, Grains Per Gallon, Computed from Alkalinity, 9.00 A. M. 2.14 . 1.19 9.20 6440 2.17 I-I5 9-30 2.12 i-35 1-47 1.21 940 2.03 i-33 9-50 6,570 I.96 1.41 10.00 1.90 i-44 i-53 i-49 10.10 i-93 i-45 10.20 1.67 i-77 10.30 CC 6,640 i-74 1.04 1.10 1.69 IO.4O CC 2.00 1-36 10.50 CC 2.00 1-36 11.OO CC 7,720 i-94 0.88 0.80 i-44 II.IO cc 2.06 1.29 11.20 6,320 i-95 i-43 H-3O cc 2.00 i-54 i-73 1-36 II.40 cc 1.96 1.41 n-50 cc 6,020 2.10 1-23 12.00 M. 2.24 0-79 o-93 1.06 12.10 P. M. 2.22 1.09 12.20 cc 6,210 2.31 0.83 o-97 12.30 2.17 0-94 I-I5 12.40 c c 2.31 o-97 12.50 cc 2.32 0.96 1.00 cc 5,840 2.23 0-97 1.16 1.08 1.10 cc 2.36 0.91 1.20 cc 6,290 2.36 0.91 1-30 2.22 1.11 1-23 1.09 1.40 2.29 1.00 i-5o cc 6,940 2.19 1.12 2.00 cc 2-23 1.24 1.24 1.08 2.10 cc 2.27 1-03 2.20 cc 2.27 1-03 2.30 cc 5470 243 i-i7 1.58 0.83 2.40 c c 2.22 1.09 2.50 5,640 2.05 1-30 3-oo 2.12 1.24 i-53 1.21 3-io cc 2.18 1.14 3-20 cc 2.15 i-i7 3-30 cc 5,440 2.20 o-97 1-25 1.11 3-40 cc 2.10 1.24 3-50 2.10 1.16 1.24 4.00 cc 5440 1.96 0.90 141 VARIATION IN APPLICATION OF COAGULANT. 163 TABLE C.- Continued. Effluent Alkalinity Sulphate of Alumina Used. Quantity, of Effluent, Pounds Grains Per Grains Per Time. Gallons in Terms of Between Gallon, Gallon, Between Calcium Car- Observa- by Weight, Computed Observa- bonate, Parts tions. Between from tions. Per 100,000. Observations. Alkalinity. 4.10 A. M. 2.08 1.26 4.20 " 2.07 1.27 4-30 " 5>37o 2.38 O.85 I.II O.89 440 11 2.II 1.22 4-50 " 2.00 I-36 5-00 " 5450 2.03 0-95 1.22 i-33 6.00 " 10,250 2.65 i-94 i-34 0-55 7.00 " 12,380 2.07 1.17 8.00 " 9-050 2.60 1.62 1-25 0.61 9.00 " 10,660 378 2.48 9-30 " 2.50 0-74 10.00 " 10,550 2.4I 1.71 i-i3 0.85 10.23 • " 2.l6 1.16 Averages, 2.15 1-30 1.17 Notes:-The average alkalinity of the applied water, during the test, was 3.09. Valve opened after washing, at 8.10 A. M., June 10, 1898. Valve closed for washing, at 10.24 P- June IO, 1898. Changed from Coagulant Tub No. 2 to Coagulant Tub No. I, at 11.10A. M., June 10, 1898. Changed from Caogulant Tub No. 1 to Coagulant Tub No. 2, at 8.00 P.M.,June 10, 1898. Table D. Special Test with the Warren Filter, Variation in the Application of Coagulant, From 9.00 A. M. to 11.13 P. M.,June 23, 1898. Time. Effluent Quantity, Gallons Between Observa- tions. Alkalinity of Effluent, in Terms of Calcium Car- bonate, Parts Per 100,000. Sulphate of Alumina Used. Pounds Between Observa- tions. Grains Per Gallon, by Weight, Between Observations. Grains Per Gallon, Computed from Alkalinity. 9.00 A. M. O.64 2.38 2.67 2.26 9-10 " O.64 2.26 9-20 " O.7O 2.19 9-30 " 7,070 RIO 3-12 3-09 I.69 940 " 0.60 2.31 9-50 " O.85 2.00 10.00 " 6,890 o-75 2.25 2.28 2.13 10.10 " 0.65 2.25 10.20 " o-57 2-35 10.30 " 6,630 0.98 3-75 3-96 I.84 IO.4O " 0-95 1.88 10.50 " o-55 2.38 11.OO " 6,660 o-57 2.04 2.14 2-35 II.10 " 0.82 .... 2.04 11.20 " 0.52 2.41 11-30 " 6,270 0.60 1.86 2.08 2.31 11.40 " 0.65 2.25 11-50 " 0.67 2.23 164 REPORT OF RESIDENT ENGINEER,-WARREN FILTER. TABLE D.-Continued. Time. Effluent Quantity, Gallons Between Observa- tions. Alkalinity of Effluent, in Terms of Calcium Car- bonate, Parts Per 100,000. Sulphate of Alumina Used. Pounds Between Observa- tions. Grains Per Gallon, by Weight, Between Observations. Grains Per Gallon, Computed from Alkalinity. 12.00 M. 6,150 0.7° 1-65 1.88 2.19 12.10 P. M. O.6O 2.31 12.20 " O.65 2.25 12-30 " 6,030 O.7O 1-50 i-74 2.19 I2.4O O.76 .... .... 2.II 12.50 " O.69 2.20 I.OO " 5,990 O.72 1-23 i-44 2.l6 I.IO " 0-79 2.08 1.20 " 1.14 I.64 1-30 " 6,100 0-75 1.68 i-93 2.13 1.40 " 0.80 2.06 i-5o " 0-73 2-15 2.00 " 7,110 O.9O 1.89 1.86 i-94 2.10 1-03 1.78 2.20 " 0.85 2.00 2.30 " O.87 1.98 2.40 " O.98 1.84 2.50 " 0.80 . . . . 2.06 3-00 " 11,840 0.82 3-90 2.31 2.04 3-io " 0-74 2.14 3-20 " o-79 2.08 3-30 " 0.72 2.16 3-40 " o-75 2.13 3-50 " 0.78 2.09 4.00 " 0.80 2.06 4.10 " 0.82 2.04 4.20 " 0.82 2.04 4-30 " 17,730 o-79 6.30 249 2.08 440 " 0.62 2.29 4-50 " 0.65 2.25 5-oo " 5,820 0.63 2.70 3-25 2.27 5-io " 0.61 2.30 5-20 " 0.61 2.30 5-30 " 0.62 2.28 6.00 " 10,730 0.62 3-97 2-59 2.28 7.00 " 0.70 2.19 8.00 " t.i8 I.5Q 9.00 " 32,310 i-73 3.60 0.78 0.90 10.00 " 1.84 0.76 10.25 " 1.90 .... 0.69 11.00 " 21,430 2.02 0.66 11-13 " 2.20 0.31 Averages, 0.83 .... 2.19 2.02 Notes:-The average alkalinity of the applied water, during the above test, was 2.45. Valve opened after washing, at 8.23 A. M., June 23, 1898. Valve closed for washing, at 11.19 P. M., June 23, 1898. Changed from Coagulant Tub No. I to Coagulant Tub No. 2, at 10.05 A. M., June 23, 1898. Changed from Coagulant Tub No. 2 to Coagulant Tub No. 1, at 5.20 P. M., June 23, 1898. VARIATION IN APPLICATION OF COAGULANT. 165 Table E. Special Test with the Warren Filter. Variation in the Application of Coagulant, From 9.00 A. M., August 12, to r.go A. M., August 13, 1898. Effluent Alkalinity SULPHATE OF ALUMINA USED. Quantity, of Effluent, Pounds Grains Per Grains Per Time. Gallons in Terms of Between Galion, Gallon, Between Calcium Car- Observa- by Weight, Computed Observa- bonate, Parts tions. Between from tions. Per too,000. Observations. Alkalinity. 9-3° A. M. 9,120 1.80 1-38 .... 10.00 CC 74/0 i-5o I.4I 10.30 CC 6,680 1-05 I.IO 11.00 6,460 1-05 1.14 n-30 7,040 1.20 1.19 12.45 P. M. 1.00 ft 1.10 1.22 1.10 CC 1-30 o-97 1.11 17,410 3-oo 1.21 1.20 CC L15 1.16 i-30 CC 5,35° i-35 0.90 1.18 0.91 1.40 115 1.16 i-5o 1.00 i-35 2.00 9,260 0.80 5-io 3-86 1.60 2.10 CC o-55 1.91 2.20 0.56 1.90 2.30 CC 8,150 0.56 i-95 1.68 1.90 2.40 0.50 1.98 2.50 0-45 2.04 3-oo 8,330 0.45 1.20 1.01 2.04 3.10 0.32 2.20 3-20 0.32 2.20 3-30 CC 8,150 0-54 3-oo 2.58 i-93 3-40 0.60 1-85 3-50 CC 0-75 1.66 4.00 CC 7,610 0-75 2.70 2.48 1.66 4.10 CC 0.60 1-85 4.20 0.60 1-85 4-30 8,690 0.70 1.80 i-45 1.72 4-40 0.60 1.85 4-50 o-55 1.91 5-oo CC 7,180 0.68 1.80 1.76 i-75 5-io 0.65 i-79 5-20 CC 0.80 1.60 5-30 7,290 o-95 i-95 1.87 1.41 5-40 1.00 i-35 5-50 1-05 1.29 6.00 1.00 i-35 6.10 1.00 1.35 6.30 (c 16,620 1.26 3.00 1.26 1 03 166 REPORT OF RESIDENT ENGINEER,-WARREN FILTER. Time. Effluent Quantity, Gallons Between Observa- tions. Alkalinity of Efflue t, in 1 enns of Calcium Car- bonate, Parts Per 100,000. Sulphate or Alumina Used. Pounds Between Observa- tions. Grains Per Gallon, by Weight, Between Observations. Grains Per Gallon, Computed from Alkalinity. 7-00 " 6,350 1.22 O.9O 0-99 1.08 7-30 " 8,010 i-34 1.20 1-05 O.92 8.00 " 7,no 1-38 1-05 1-03 O.87 8-30 " 8,260 1.24 1-65 1.40 1-05 9.00 " 7,220 1.20 2.70 2.62 1.10 9-30 " 7,140 1.00 3-07 3-oi i-35 10.00 " 7,000 0-74 1-65 1-65 1.68 10-30 " 7,540 0.80 T-57 1.46 1.60 11.00 " 7,540 0.88 1-50 i-39 i-5o 11.30 " 7,000 1.12 1.27 1.27 1.20 12.00 Mid. 7,180 1-05 i-35 1-32 1.29 12.30 A. M. 7,i8o 1-30 1.27 1.24 0-97 1.00 " 7,570 1.00 1.20 1.11 i-35 i-30 " 6,890 1-25 0.90 0.91 1.04 i-5o " 1.40 0.85 Averages, 0.89 i-57 i-49 TABLE E,-Continued. Notes:-The average alkalinity of applied water, during the above test, was 2.08. Valve closed for washing, at 12.45 P- M., August 12, 1898. Valve opened after washing, at 1.11 P. M., August 12, 1898. Valve closed for washing, at 1.46 A. M., August 13, 1898. Changed from Coagulant Tub No. 2 to Coagulant Tub No. 1, at 1.30 P. M., August 12, 1898. Changed from Coagulant Tub No. 1 to Coagulant Tub No. 2, at 8.55 P. M., August 12, 1898. BACTERIAL EFFICIENCY AFTER WASHING. It is of considerable interest in mechanical filtration, to determine the bacterial efficiency after washing. Numerous samples were collected, for the purpose of demonstrating this feature, and the results of some of the representative tests are given in the following table. It was also true, at times, that, as the filter became clogged and the time for washing approached, the number of bacteria in the effluent increased, as is ex- hibited in some of the instances chosen. BACTERIAL EFFICIENCY AFTER WASHING. 167 Table F. Bacteria in Effluent from Warren Filter at Times of Washing. Bacteria Time. Per C. C. Remarks. Bacteria Time. Per C. C. Remarks. Calendar Date:- 12.28 P. M. i-49 " 2.20 " 2.36 " 2.50 " 3.10 " 3-i5 " 3-25 " 3-35 " 3-45 " 3-55 " Calendar Date 2.10 A. M. 2.25 " -March 36 30 33 32 406 520 166 120 103 83 :-April 5i 50 31, I898. V. s. V. 0. I, 1898. Calendar Date:-April 3.10 A. M. 134 3-25 " 147 3.40 " 108 3-55 " 128 4.10 " 132 4-25 " 132 4-35 " 4-53 " 672 4-58 " 494 5.18 "■ 236 5.28 " 198 5-38 " 147 548 " 148 5-58 " 143 6.30 " 100 2, 1898. V. s. V. 0. 2.40 " 2-55 " 3-io " 43 54 45 Calendar Date:-April 14, 1898. 1.00 P. M. 32 0 (( t 3-25 " 3-40 " 3-53 4-09 " 4-i4 " 4-24 " 4-34 444 " 4-54 " 5-°4 " 85 39 252 358 222 104 89 81 83 V. s. V. 0. 3.00 3-n 3.16 3-20 340 3-50 3-53 3-56 4.00 4-05 " 54 65 " 77 <c 156 290 " 118 " ' 62 105 V. s. V. 0. Calendar Date 12.13 P. M. i-3O " 145 " 2.00 " 2.15 " 2.48 " 3.06 " 3.11 " 3.16 " 3-26 " 3-36 " 3-5i " 4-34 " :-April 103 163 145 166 149 306 166 5M 379 384 293 336 272 I, 1898. V. s. V. 0. 4.10 104 4-20 " 56 4.41 " 64 5-oo " 36 Calendar Date:-April 1.15 A. M. 19 2.28 " 12 2.31 " 246 " 735 2.49 " 721 2.52 " 158 2.56 " 88 3-0! " 65 3.06 " 47 3.16 " 36 4.17 " 21 6.46 " 8 20, 1898. V. s. V. 0. REPORT OF RESIDENT ENGINEER,-WARREN FILTER. 168 Time. Bacteria Per C. C. Remarks. 1 Time. I Bacteria 'er C. C. Remarks. Calendar Date :-April 21, 1898. Calendar Date June 2, 1898. 3.06 A. M. 8.00 " 6 4 12.01 A. M. 2.07 " 92 76 8.08 " V. S. 2.14 " V. s. 8.29 " 8-31 " 8-34 " 124 30 V. 0. 2.36 " 2-39 " 2.42 " 625 475 V. 0. 8.40 " 8.51 " 17 12 2.46 " 2.56 " 3-36 " 550 400 16 - Calendar Date 9.06 A. M. :-April 23, 1898. 17 6.00 " 16 10.00 " 11.00 " 11.30 " 15 11 6 Calendar Date 6.00 P. M. 8.11 " June 42 64 2, 1898. 12.00 M. 10 8.17 " V. s. 12.01 P. M. • . V. s. 8.38 " V. 0. 12.19 " 12.25 " 84 V. 0. 8.41 " 8-44 " 650 375 12.28 " 40 8.48 " 275 12.38 " 12.58 " 1.18 " 2.00 " 26 7 15 11 8.58 " 9-38 " 12.00 Mid. 125 19 8 • 3-02 " 4.00 " 10 4 Calendar Date: 8.05 P. M. June 6 6, 1898. 5.00 " 2 8.10 " V. S. 6.15 " 7.00 " 8.00 " 9.01 " 10.00 " [2.00 Mid. Calendar Date 1.00 A. M. 2.00 " 3-02 " 3-45 " 4-i3 " 4.16 " 4-35 " 4-38 " 4-41 " 4-55 " 5-05 " 8 8 6 3 9 19 :-April 5 5 6 83 16 264 52 35 12 18 24, 1898. V. s. V. 0. 8-35 " 8.36 " 8-39 " 843 " 8-53 " 9-33 " 37 20 20 16 9 V. 0. TABLE F,-Contimitd. BACTERIAL EFFICIENCY AFTER WASHING. 169 Bacteria Time. Per C. C. Remarks. Time. Bacteria Per C. C. Remarks. Calendar Date:-August 12, 1898. Calendar Date: :-August 13, 1898. 12.44 P. M. II 1.50 A. M. l66 V. s. 12.45 " .. V. S. 2.10 " V. 0. 1.11 " .. V. 0. 2.15 " 121 1.12 " 7i 2.18 " 850 i-i5 " 1,025 2.21 " 1,125 1.18 75o 2.25 " 525 1.22 " 1,700 2-35 " 550 1-32 " i,475 3-i5 " 66 2.12 46 3-20 " 12 9.21 " 66 12.00 Mid. 43 TABLE F,-Continued. Notes :-V. S., means Effluent Valve Closed before Washing. V. O., " " " Opened after " The following records, relating to the above tests, are copied from the Monthly Record Sheets :- Date, 24 Hours Ending 9.00 A. M. Average Condition of Applied Water. Sulphate of Alumina. Used,-Grains Per Gallon. Turbidity. Bacteria Per C. C. April 1, 1898 O.l8 8,500 i-97 " 2, " 0.17 5,375 0.90 " i5> " O.O4 2,980 0-55 20, " 0.04 2,75° 0.81 21, " 0.06 2,162 1.09 24, " 0.04 2,410 1.38 Tune 2, " 0.04 1,700 0.66 " 3, " 0.06 1,420 0.62 " 7> " 0.02 3,46o 1.04 August 13, " 0.31 8,850 i-53 SPECIAL EXPERIMENTS, TO SHOW THE EFFECT OF USING DIFFERENT QUANTITIES OF COAGULANT. During the month of May, 1898, special experiments were under- taken with the the Warren Filter, to determine the effect of passing the water through the bed without the application of coagulant, with very little, and with large amounts of coagulant. Most of these experiments were carried on when the turbidity was not especially high, that is not above 0.10; in fact, we were obliged to postpone some special ones when the river became too muddy. The general features of these tests are brought out in the regular monthly tables, but a few of the more important facts are best explained by some special tables. The first one, Table G, shows, in two parts, the effect of discontinuing the use of coagulant and how soon this is made evident by the character of the effluent. The second, Table H, shows how long it takes for the filter to REPORT OF RESIDENT ENGINEER,-WARREN FILTER. 170 recover, after it has been operated without coagulant, when the coagulant has just been applied, and in a large amount. It is a remarkable fact that without the use of coagulant the mechanical filter clogs much more slowly than otherwise. In fact, while operating without coagulant, during the first few days of May, the filter ran 117 hours without washing, and then was only washed because a clear bed was desired to start another experi- ment. Table G. Bacteria in Effluent,-No Coagulant Used. Calendar Date, 1898. Time. Bacteria Per C. C. Remarks. May i 8.36 A. M. Valve Opened after Washing, (( if 9.02 " Supply of Coagulant Shut Off. tt It 9-30 " 28 It it 9-45 " 134 Turbid. tt tt 10.00 " 358 it tt 10.20 " 644 Very Turbid. tt tt 11.00 " 1,120 tt tt 1.00 P. M. 1,050 1-30 " 1,372 tt it 3-20 " 1,322 5-oo " 1,421 7-05 " 1,540 tt tt 9-03 " I,l62 tt tt 11.00 " 1,274 May 14 9.00 A. M. 20 Supply of Coagulant Shut Off. 11-05 " 15 Valve Opened after Washing, 8.35 P. M., May 13. tt tt T2.O2 P. M. 850 Slightly Turbid. it tt 12.16 " 900 tt tt 12.20 " 1,200 Turbid. It tt 12-45 " 1,300 tt Ci 2.10 " 21,000 Very Turbid. It i 2.27 " Valve Closed for Washing. tt It 2-53 " Valve Opened after Washing. 2-55 " 500 tt I. 2.58 " 50,575 I1 it 3-02 " 225 tt It 3-12 " 60,900 4.00 " 2,730 tt It 5-26 " 64 tt tt 7.00 2,400 tc tt 9-04 " 3,750 Note:-In examining the first set above it should be noticed that there was a wash- ing a short time prior to the beginning of the test. The last washing, previous to the sec- ond test, occurred many hours before, and evidently the filter bed was covered with a coagu- lated film and prepared to filter for a longer time without any coagulant being added. It may be said of the smaller results, secured shortly after the next washing, at 2.55 P. M., that the samples evidently contained some of the wash water which (as the Jewell effluent was alone used for this purpose, at this time) was better than the water which passed thiough the bed of the Warren Filter. 171 Table H. Bacteria in Effluent,-Coagulant Applied al Approximate Rate of Two and Three-Quarters Grains Per Gallon. EFFECT OF DIFFERENT QUALITIES OF COAGULANT. Calendar Date, 1898. Time. Bacteria Per C. C. Remarks. May 6 CC CC 9.00 A. M. Began to Supply Coagulant. 9-04 " 1,610 a cc 9-35 " 1,113 Valve Opened after Washing, 6.00 A. M., May 6, 1898. CC 11 9-55 " 478 Ci 11 10.05 " 140 Becoming Clear. Cl 11 10.20 " 34 Clear. cc 11 11.00 " 19 cc cc 12.00 M. 2 cc cc 3.00 P. M. 2 11 *4 5-oo " 3 7.00 " 7 CC ll 9.00 " 6 CC Cl 11.00 " 5 " 7 12.03 A. M. 5 12.12 " Valve Closed for Washing. Cl CC 12.32 " • • Valve Opened after Washing. 12.35 " 33 CC CC 12.38 " 14 CC Ci 12.42 " 12 CC CC 12.52 " 9 1.02 " 7 CC CC 1-32 " 9 CC CC 3-03 " 2 CC CC 5-oo " 3 CC CC 7.00 " 2 Notes:-The above table also shows that washings have less effect when considerable coagulant is used. The following records, relating to the above tests, are copied from the Monthly Record Sheets: - Date, :'4 Hours Ending 9.00 A. M . Average Condition or Applied Water. Sulphate of Alumina Used,-Grains Per Gallon. Turbidity. Bacteria Per C. C. May 1, 1898 Windy 4,380 i-i5 " 2, " 0.05 4,380 0.00 " 7. " 0.04 3,060 2-73 " I5> " 0.06 7,400 0.00 Tabulation of Results. The tables presented upon the following pages give the quantitative and bacterial results secured, by days, also the totals and averages for each month. The results of the chemical analyses are given in Appendix No. 2, page 260 et seq. 172 REPORT OF RESIDENT ENGINEER,-WARREN FILTER. RECORD OF WARREN MECHANICAL FILTER, For the Month of January, 1898. £ ac Tot'Is, 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Date for 24 Hours Ending 9.00 A. M. 10.1 H-1 o to to bD p to W p p p p p p p CO CD CO 00 O p Cl p ; ; ; ; ; ; ; ; ; ; ; ; ; O W O C. Q C C ~ C: C 4^ C ic O' Hours in Operation. 133,000 1,862,000 ! ! 1 ! 89,000 106,000 83,000 0 115.000 137,000 132,000 120,000 84,000 0 0 0 54,000 77,000 53,000 275,000 255,000 282,000 Total Passed. Quantity in Gallons. 117,000,000 143.000,000 136,000,000 107,000,000 0 121,000,000 152,000,000 136,000,000 127 000,000 146,000,000 0 0 0 104,000,000 120,000,000 102,000,000 105,000,001) 103,000,000 106,000,000 Rate of Filtration Per Acre Daily. 6,300 88,800 0 10,000 * 8,000 0 5,700 6,300 7,100 5,900 10,000 0 0 0 5,100 4,900 3,400 11,200 6,000 5,200 1 Wash Water. £ Number of Times. , Wash- ing. 13.9 195 "6 25 16 0 12 12 27 14 18 0 0 0 9 9 8 20 14 11 Duration in Minutes. 22.6 316.5 23.8 38.7 13.5 0.0 17.2 30.3 12.5 16.2 8.2 0.0 0.0 0.0 45.6 24.7 16.1 20.0 22.6 27.1 Total Pounds. Sulphate of Alumina Used. 1.19 O O O IO QI Q o P O O O O to H- uGji ~ wb oboe-, bui'icb'-* cn do i : : . : . . . ; . . ! . ^jr^-^MCRtooQoco 4- Ui'U' O 4^ m - I Grains Per Gallon. O 0.89 0.84 0 48 0.26 ,0.20 0.12 0.16 0.16 0.00 0.00 0.00 0.19 0.25 0.22 0.11 0.08 0.09 Applied Water. Turbid- ity. § : = : : 88: ; ; 88888: : : : : : 0.0 o o o o o Effluent. 19,543 30,987 40,350 45,325 21,275 22,700 11,000 12,300 19,000 12,650 15,000 14,050 6,825 2,600 Applied Water. Bacteria Per Cubic Centimeter. 12,950 11,787 19,933 Settled Water. 950 2,276 392 1,064 2,523 1,381 382 323 494 1,621 1,234 414 147 92 Effluent. Notes:-Percentage of Bacteria removed, 95.14. Percentage of Filtrate used for washing, 4.8 Filter not in operation for 72 hours, ending 9.00 A. M., January 25, on account of repairs to the building. * Wash meter broken; quantity of Wash Water estimated at 500 gallons per minute of actual wash- ing time. The Warren Effluent Meter was found to register 13 per cent, in excess to March 14, 1897, then 5 per cent, in excess to April 5, and then 4 per cent, in excess after the last date. All effluent quantities are the proper percentage less than the meter records. There was about 2,400 gallons wasted from the surface of the Warren Filter each time it was washed. TABULATION OF RESULTS. 173 RECORD OF WARREN MECHANICAL FILTER, For the Month of February, 1898. Av'gs, Tot'Is, 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 Date for 24 Hours Ending 9.00 A. M. 21.3 597.2 to to to to to to to to to to totototo>-ii->toto>-'totototototototo to co co co o co w co co p p p to to p co oo p co p j-* co w co co w w co o. '^- a h <x vrc.: 'i o o ot w --i b -^i c s c. 'i o o i: b o Hours in Operation. 250,000 7,005,000 304,000 302,000 316,000 319,000 323,000 292,000 277,000 221,000 211,000 282,000 261,000 245,000 240,000 295,000 275,000 286,000 285,000 0 184,000 195,000 201,000 204,000 208,000 208,000 266,000 267,000 274,000 264,000 Total Passed. Quantity in Gallons. 104,000,000 115,000,000 113,000,000 122,000,000 121,000,000 124,000,000 110,000,000 104,000,000 90,000,000 114,000,000 105,000,000 115,000,000 116,000,000 118,000,000 120,000,000 107,000,000 113,000,000 123,000,000 0 81,000,000 73,000,000 76,000,000 76,000,000 77,000,000 90,000,000 102,000,000 100,000,000 104,000,000 103,000,000 Rate of Filtration Per Acre Daily. 9,500 266,300 7,100 5,600 *15,500 11,000 11,000 6,000 5,500 7,000 6,000 6,000 10,500 13,500 11,500 23,500 16,500 16,000 *10,000 o 10,100 6,300 11,000 6,700 5,000 6,200 12,900 6,200 13,100 6,600 Wash Water. 1.6 !-JtO>-itOI-'l-iH-'tOI-'H-'CtOCOCO^tOCOtO>-'l-'t-'l-'l-1tOtOtOS-'H-' Number of Times Wash- ing. 17.8 499 15 12 31 22 22 12 11 14 12 12 21 27 23 47 33 32 20 0 19 10 19 10 8 9 18 10 20 10 Duration in Minutes. 25.0 701.2 17.2 23.5 18.0 22.6 24.2 18.0 15.9 16.6 10.5 29.0 17.2 13.7 36.4 35.5 50.7 44.3 70.1 0.0 22 6 21.4 23.7 22.4 8.7 25.5 13.1 26.5 33.9 40.0 Total Pounds. i Sulphate of Alumina Used. p 0.40 0.54 0.40 0.50 0.52 0.43 0.40 0.53 0.35 0.72 0.46 0.39 1.06 0.84 1.29 1.08 1.72 0.00 0.86 0.77 0.82 0.77 0.29 0.86 0.34 0 69 0.87 1.06 Grains Per Gallon. p Or 0.08 0.08 0.09 0.06 0.05 0.05 0.04 0.04 0.14 0.26 0.30 0.48 0.47 0.32 0.25 0.19 0.13 0.09 0.08 0.16 0.15 0.13 0.11 0.08 0.07 0.05 Applied Water. Turbid- ity. koo- • 22' P P © • po. PPP- • coo. . . poo. o. : OO; ooto. GO: P O ; ; to G O ; : • ggg- o- G G OC W O O Cn G O WOO GOO' O' Effluent. 9,430 2,350 2,250 2,775 2,700 1,575 1,425 1,700 3,550 8,025 17,500 25,600 124,150 '23,600 1 9,250 11,025 7,050 12,025 10,150 12,350 9,400 12,112 । 7,750 | 8,600 : Applied Water. Bacteria Per Cubic Centimeter. I 7,127 4,000 2,150 1,175 1,587 3,250 8,175 8,850 22,600 20,400 10,800 4,950 3,050 3,425 10,125 4,350 5,500 6,450 7,450 Settled Water. 238 82 128 258 378 । 208 130 72 675 343 161 280 350 326 265 59 437 471 197 85 115 140 72 Effluent. Notes:-Percentage of Bacteria removed, 97.48. Percentaee of Filtrate used for washing, 3.8. * Wash meter broken from February 3 to February 17, inclusive. Quantity of Wash Water esti- mated at 500 gallons per minute of actual washing time. 174 REPORT OF RESIDENT ENGINEER,-WARREN FILTER. RECORD OF WARREN MECHANICAL FILTER, For the Month of March, 1898. Av'gs Tot'Is, e 3 4 5 6 7 8 8 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Date for 24 Hours Ending 9.00 A. M. 22.3 691.4 tc W W K W M W W w K IO I I K K Iv IC W 10 t-C W M W W IC c; W IC W O it- - W w 05 w w © w w w w w w w w w w _w w to OS L h ii c; ic'liio ■'I '1 o: IC w wn W 4:- OS W M M S CO U c: c: 'I Hours in Operation. 273,000 8,468,000 189,000 269,000 273,000 268,000 274,000 271,000 288,000 276,000 271,000 268,000 272,000 234,000 276,000 279,000 243,000 298,000 301,000 290,000 290,000 304,000 134,000 195,000 271,000 321,000 252,000 300,000 303,000 307,000 291 000 291,000 316,000 Total Passed. Quantity in Gallons. *108,000,000 99,000,000 105,000,000 102,000,000 100,000,000 104,000,000 101,000,000 108,000,000 103,000,000 101,000,000 '102,000,000 103,000,000 107,000,000 105,000,000 104,000,000 110,000,000 113,000,000 114,000,000 111,000,000 108,000,000 106,000,000 101,000,000 117,000,000 115,000 000 124,000,000 96,000,000 114,000,000 115,000,000 117,000,000 109,000,000 113,000,000 121,000,000 Rate of Filtration Per Acre Daily. 9,500 294,400 11,500 5,800 3,400 6,400 11,800 6,200 5,700 6,200 6,100 6,100 6,000 11,400 9,300 6,100 10,200 9,700 11,300 13,100 7,100 12,200 0 14,700 5,700 19,900 12,500 15,600 14,500 13,300 6.100 15,000 11,500 Wash Water. On GO tC GO 1- IC tc W W W H K o tc 1- tc IC IC IC tc to H - H H H •-" W H I--4 IC Number of Times. Wash- ing. to 383 h-1 1-1 H-1 tO 1-1 tO t- I-1 1-1 H-1 4 1 M H-4 >-1 Duration. Minutes. Lu 2183.5 1 16.4 25.4 21.3 23.8 23.7 18.2 24.6 30.1 21.3 22.1 17.9 25.0 24.7 28.0 37.7 5.4 49.9 39.0 28.6 62.4 33.7 60.7 112.0 545.8 347.4 206.5 61.5 39.7 34.2 57.9 98.6 Total Pounds. Sulphate of Alumina Used. 1.81 0.61 0.66 0.55 0.62 0.61 0.47 0.60 0.76 0.55 0.58 0.46 0.62 0.63 0./0 1.09 1.07 1.16 0.94 0.69 1.44 1.76 2.18 2.89 11.90 9.64 4.82 1.42 0.91 0.82 1.38 2.18 Grains Per Gallon. 0.30 0.04 0.05 0.05 0 06 0.07 0.04 0.05 0.05 0.06 0.05 0.05 0.08 0.12 0.12 0.11 0.10 jo. 09 0.08 0.49 0.90 ;1.00 2.38 0.90 0.41 0.20 0.17 0.20 0.29 0.50 A plied Water. Turbid- ity. .001 .000 .000 .000 .001 .000 .000 .000 .000 .000 .000 .000 .000 .000 .000 .000 .000 .000 .003 .000 .010 .010 .000 .000 .000 Effluent. 11,747 6,125 7,650 7,450 4,925 4,475 5,150 3,400 5,100 5,075 5,175 5,700 5,475 6,525 12,025 14,175 12,400 7,350 8,600 9,900 56,000 55,483 23,267 14,400 7,000 4,800 4,750 9,967 16,583 , Applied Water. Bacteria Per Cubic Centimeter. 6,164 7,450 6,800 5,475 3,850 3,175 4,865 2,600 3,625 5,000 3,650 3,975 6,075 7,800 10,050 7,700 6.625 10,125 5,850 14 733 7,850 4,500 4,775 3,200 2,225 3,500 14,800 Settled Water. 164 269 236 210 63 55 35 31 35 57 77 200 450 209 88 498 109 91 206 61 192 183 699 215 88 54 76 116 44 58 Effluent. Notes :-Percentage of Bacteria removed, 98.60. Percentage of Filtrate used for washing, 3.5. TABULATION OF RESULTS. 175 RECORD OF WARREN MECHANICAL FILTER. For the Month of April, 1898. II Date for 24 Hours 1! Ending 9.00 A. M. Hours in Operation. Quantity in Gallons. Wash- ing. Sulphate of Alumina Used. Turbid- ity. Bacteria Per Cubic Centimeter. Total Passed. Rate of Filtration Per Acre Daily. Wash Water. Number of Times. Duration. Minutes. Total Pounds. Grains Per Gallon. Applied Water Effluent. Applied Water. Settled Water. Effluent. 1 23.4 314,000 119,000,000 12.600 2 14 88.4 1.97 0.18 .000 8,500 4,450 69 2 23 4 323.000 122,000,000 11,700 2 14 41.6 0.90 0.17 000 5,375 5,750 220 3 23.7 321,000,120,000,000 6,200 1 7 34.5 0.750.13 .000 5,287 4,175 135 4 23 4 314,000'119,000,000 9,900 2 13 35.2 0.780.11 3,667 3,600 -61 5 13.8 180,000.115,000,000 0 0 0 12.5 0.490.08 .000 2,937 3,400 100 6 23.2 330,000.126,000,000 10,400 2 14 27.9 0.590.07 .000 2,512 1.900 97 7 23.6 336,000'126,000,000 5.700 1 8 25.0 0.520.07 .000 2,562 1,600 134 8 23.7 319,000'119,000.000 4,600 1 7 23.8 0.520.08 .000 1,725 1,425 121 9 23.4 327,000124,000,000 11,300 2 13 24 6 0.530.07 .000 2,112 1,800 106 10 23.7 335,000 125,000.000 5,600 1 7 27.2 0.570.05 .000 2,925 3,075 91 11 23.7 324,000'121,000,000 6,200 1 7 21.3 0.460.04 2,917 2,100 33 12 23.7 333,000125.000,000 5,600 1 7 13.6 0.290.04 .000 3 037 3,050 155 13 23.7 332,000124,000,000 6,100 1 7 23.5 0.500.04 .023 3,575 2,925 135 14 23 7 321,000120.000,000 5,200 1 7 18.7 0.410.04 .000 2,537 2,C00 59 15 23.7 358,000'134,000,000 6,200 1 9 28.3 0.55 0.04 .000 2,980 2,175 79 16 23.4 362,000137.000,000 10,500 2 14 28.7 0.560.04 .000 2,612 1,717 45 17 23 3 354,000135,000,000 12,500 2 15 28.6 0.570.03 .000 1,525 900 43 18 23.7 369,000 138,000,000 8,100 1 10 36.9 0 70,0.06 2,317 1,000 14 19 22.1 294,000418,000,000 12,000 2 15 30.4 0.720.05 2,525 1,575 20 20 23.7 321,000.120,000,000 4,600 1 6 37.1 0.810.04 .000 2,750 1,225 32 21 23.3 305,000116,000,000 11,900 2 14 47.7 1.090.06 .000 2,162 1,450 6 22 23.7 328.000 113,000,000 5.800 1 1 7 50.7 1.080.05 .000 1,537 775 8 23 22.9 297,000115,000,000 4,900 | 1 6 55.0 1.300.04 .000 1,425 1,350 39 24 23.4 318,000 120,000,000 10,400 2 13 62.6 1.380.04 .000 2,410 725 15 25 23.7 313,000 117,000,000 5,400 1 7 31.4 0.700.06 7,350 8,750 71 26 23.4 325,000123,000,000 11,800 2 13 58.0 1.25'0.20 .000 16,000 7,925 137 27 23.4 317,000120,000,000 10,800 2 13 74.3 1.640.23 .00018,912 9,200 51 28 23.7 303,000113,000,000 5,600 1 7 62.2 1.440.21 .00017,725 9,275 78 29 19.6 270,000.122,000,000 17,800 3 25 51.4 1 330.12 .000 10,587 7,525 140 30 23.6 312,000 117,000,000 6,700 1 8 64.9 1.46 0.09 .000 7,812 3,325 34 Tot'Is, 690.7 9,555,000 246,100 43 307 1166.0 Av'gs, 23.0 318,000 122,000,000 8,200 । 1.410.2 39.0 0.86 0.08 .001 5,010 3 358 78 Notes-Percentage of Bacteria removed, 98.44. Percentage of Filtrate used for washing, 2.6. 176 REPORT OF RESIDENT ENGINEER,-WARREN FILTER. RECORD OF WARREN MECHANICAL FILTER, For the Month of May, 1898. Av'gs, Tot'ls, HOCOXMOiOirfiWtOHOCOOOSa W WHOCOCOMaOi^WWH Date for 24 Ending 9.00 Hours A. M. 23 730 b5ts5tOb3b5tOtObObObOtsCb2tOt>2tsCb5bOtObOK)tOts5tOt>5bOts5bOtOtOt>3tO t^CO.PWWWWWWWWWWWWWWWWWWWWWWWifitl^^W Hours in OnPTA.fi nn. Ol-^OO 4' C 7: 1: '1 C 'Ui c: C. CO O W G o: W '.i Ci C O O C tt s 9,440 WtOK) W.WtONtOtOKItO WWWWtOCOWWWWWWWWWWWWWW oooMoroooxiroaiNHbOHtoowotooKiHwtoHHHCoi^otio O Z C C. CI X - C X C c: a IC --x^ c: ICrf-4- 4- - li C O® MCI 7'o Total Passed. £> 000 000 000 .000 000 ,000 ,000 ,000 ,000 ,000 ,000 ,000 .000 ,000 ,000 ,000 ,000 ,000 ,000 ,000 .000 ,000 000 .000 ,000 000 ,000 ,000 000 000 000 ,000 ,000 115 114 131 127 123 117 117 119 122 126 118 123 114 122 114 120 112 120 117 123 119 103 102 100 103 98 101 100 115 103 110 114 Rate of 3 000,000 OOOOOOOOOQOOOOOOOOOOOOOOOOOOOOO OQOOQOOOOOOOOOOOOOOQOOOOOOOOOCO pooppppp opppo oop oppppoop oop oopp o o o o o o o o o o o o o o o'o o o"o o o o o o o o~o o o'o'o ooooooooooooooooooooooooooooooo OOOOOOOOOOOOOOOOOOOOOOOO0O000OO Filtration Per Acre Daily. in Gall co 248 13 14 7 15 18 76 13 6 13 6 4 7 6 7 20 14 t 5 7 7 14 3 7 8 7 8 Wash g - co qohsQ O Water. 8 P-' P-** -P-^ P^> P_> p^i PP P^ PC P-> P»^ PC pp CC ooooooooooooooooooooooooooooooo 1.1 CO co OHOHHHHbOHHHtOtOHHHI-iHWHNHWlCIHHOOOON Number of Times. m3 10.7 332 4-i 4-i 4-^ 4J bO 4-1 4-1 to IO 4-1 4-1 4-i 4-> 4-i tO tO 4-1 4-> Ot0OH'HO^OON004'©H00CDWOO0!)<IONOO4lOOOO05 Duration in Minutes. • M 2099 49 0 0 0 0 0 124 136 162 130 111 57 62 57 0 0 162 349 279 25 52 65 50 49 68 46 29 10 8 5 4 Total Pounds. SUL1 OF Al U 4^ CC' to I - 4- O> O O O CC, O O.1- - '1 4- 0' 0 4- CC ~ k-> to - ,4- o o O O' O O tO' s d m 1.55 1.15 0.00 0.00 0.00 0.00 0.00 2.73 2.97 3.43 2.90 2.40 1.33 1.36 1.33 0.00 0.00 3.54 7.85 6.11 0.57 1.35 1.75 1.33 1.29 1.80 1.21 0.77 0.23 0.22 0.13 0.11 Grains Per Gallon. eg? co 0 05 0.03 0.04 0.05 0.04 0.04 0.05 0.17 0.28 0.10 0.05 0.07 0.04 0.06 0.10 0.20 1.20 0.40 0.18 0.18 0.55 0.40 0.15 0.50 0.31 0.19 0.11 0 09 0.10 0.05 Applied Water. w a .015 .000 .002 .002 .001 002 .002 015 .000 .000 .000 000 .000 .000 015 .015 .011 .018 .018 .000 .000 .000 .000 .000 .000 .000 .000 .100 .100 110 .035 Effluent. E 5 4^ W W O bO CDOO CObOtOtO^ICnCO^I^I^i^^CO^CO^COCO^^CO^Cn Applied Water. a o ,490 ,380 ,120 ,090 ,020 ,350 ,060 ,720 ,500 ,400 ,100 ,960 ,310 ,510 ,400 050 ,600 ,000 000 500 ,700 800 200 900 500 500 400 840 410 070 500 E a > 6.000 3,800 3 530 3,550 4,320 4,350 2,550 2,250 1,350 9,800 7,500 3,120 1,350 1,850 1,850 4,600 5,450 21,100 24,600 12,000 4.020 5,600 12,700 4,400 7,200 8,300 7,300 5,050 2,970 3,420 3,350 2,130 Settled ■Water. ITERIA PE CENTIME! - - - CO 4- - 630 oiHH-iPto t-1 hcicchP aci'-ra- ^ajMajooioiococo^tow^oax - - tc ci c c, j- a -1 c a w QOOOO$iXCWG><IHQiCQOO()ct';©W>WO'N)li<pQC>QC<J< Effluent. Notes:-Percentage of Bacteria removed, 94.20. Percentage of Filtrate used for washing, 2.6 Omitting the days starred, when for experimental purposes low quantities of coagulant or none at all were used, the average bacterial results are as follows; river water, 14,400; effluent, 175; bacterial efficiency, 98.78 per cent. t Wash meter broken; quantity of wash water estimated at 700 gallons per minute of actual wash ing time. TABULATION OF RESULTS. 177 RECORD OF WARREN MECHANICAL FILTER, For the Month of June, 1898. Date for 24 Hours Ending 9.00 A. M. Hours in Operation. 1 Quantity in Gallons. Wash- ing. Sulphate of Alumina Used. Turbid- ity. Bacteria Per Cubic Centimeter. Total Passed. Rate of Filtration Per Acre Daily. Wash Water. Number of Times. Duration in Minutes. Total Pounds. Grains Per Gallon. Applied Water. Effluent. Applied Water. Settled Water. | Effluent. 1 23.6 297,000 111,000,000 10,200 1 13 15.8 0.37 0.07 035 1,960 1,670 560 2 23 6 277,000 104,000,000 6,500 1 9 26.1 0.66 0.04 .000 1,700 1,300 105 3 23.6 264,000 99,000,000 *8,300 1 11 23.3 0.62 0.06 .000 1,420 4,000 100 4 23.5 277,000 104,000,000 *7,500 1 10 22.0 0.56 0.04 .000 3,020 1,420 115 5 23.6 272,000 102,000,000 *6,700 1 9 21.2 0.55 0.03 .000 2,300 1,670 155 6 23.2 275,000 105,000,000 18,000 2 21 46.1 1.17 0.02 3,540 2,050 65 7 23.6 277,000 104,000,000 8,700 1 10 41.1 1.04 0.02 .000 3,460 770 17 8 23.1 261,000 100,000,000 16,500 2 18 40.8 1.09 0.02 .000 12,000 4,950 84 9 23.7 280,000 105,000,000 8,100 1 10 48.0 1.20 0.02 .000 23,400 9,750 84 30 23.2 264,000 101,000,000 15,000 2 16 42.3 1.12 0.02 .000 17,400 9,450 48 11 23.7 276,000 103,000,000 7,600 1 11 48.2 1.22 0.02 .000 28,300 20,400 46 12 23.2 273,000 104,000,000 15,400 2 19 43.9 1.12 0.02 .000 19,500 9,900 88 13 20.6 241,000 104,000,000 13,500 2 16 43.4 1.26 0.02 12,400 2,450 59 14 23.5 270,000 102,000,000 5,100 1 7 69.4 1.80 0.03 .000 21,200 8,050 59 15 23.6 286,000 107,000,000 9,200 1 12 68.2 1.67 0.70 .000 27,900 10,700 85 16 23.6 279,000 105,000,000 *8,000 1 10 80.1 2.01 0.80 000 16,500 6,350 43 17 23.2 286,000 109,000,000 *18,400 2 23 53.5 1.31 0.42 .000 7,650 5,700 56 18 23.6 280,000 105,000,000 8,800 1 11 38.5 0.96 0.21 .000 4,250 1,470 48 19 23.6 270,000 101,000,000 7,200 1 10 39.4 1.02 0.15 .000 6,150 6,550 150 20 23.2 277,000 106,000,000 11,600 2 19 98.4 2.49 0.40 .000 28,900 8,300 150 21 23.6 279,000 105,000,000 7,000 1 9 109.3 2.74 0.65 .000 25,100 12,800 98 22 23.7 275,000 103,000,000 7,000 1 9 117.7 3.00 0.70 .000 15,600 8,800 22 23 23.1 252,000 97,000,000 12,900 2 19 103.0 2.86 0.42 .000 5,950 2,200 8 24 23.7 281,000 105,000,000 10,600 1 15 59.7 1.49 0.23 .000 3,500 2,420 24 25 23.6 266,000 99,000,000 8,700 1 13 40.5 1.07 0.12 .000 2,700 2,070 60 26 23.1 269,000 103,000,000 15,800 2 20 52.7 1.37 0.12 .000 4.980 3,060 110 27 23.4 275,000 104,000,000 9,200 1 11 47.6 1.21 0 11 .000 360 28 23.2 275,000 105,000,000 16,300 2 21 58.7 1.49 0.07 .000 3,770 2,350 43 29 23.3 258,000 98,000,000 12,300 2 17 41.8 1.13 0.07 .000 6,250 4,970 335 30 21.8 255,000 104,000,000 10,200 1 13 47.1 1.29 0.06 .000 11,200 8,100 265 Tot'Is, 699.0 8,167,000 320,300 41 412 1587.8 Av'gs, 23.3 272,000 103,000,000 10,700 1.4 13.7 52.9 1.36 0.19 .001 11,100 5,650 115 Notes:-Percentage of Bacteria removed, 98.96. Percentage of Filtrate used for washing, 3.9. * Wash meter broken; quantity of wash water estimated at "50 gallons per minute of actual wash- ing time, July 3, 4, and 5, and 800 gallons July 16 and 17. 178 REPORT OF RESIDENT ENGINEER,-WARREN FILTER. RECORD OF WARREN MECHANICAL FILTER, For the Month of July, 1898. Date for 24 Hours Ending 9,00 A. M. Hours in Operation. Quantity in Gallonh. Wash- ing. Sulphate of Alumina Used. Turbid- ity. Bacteria Per Cubic Centimeter. Total Passed. Rate of Filtration Per Acre Daily. Wash Water. Number of Times. Duration in Minutes. Total Pounds. Grains Per Gallon. Applied Water. Effluent. Applied Water. Settled Water. Effluent. 1 23.6 265,000 99,000,000 10,100 1 12 60.3 1.59 0.29 .000 6,000 4,120 41 2 23.3 277,000 105,000,000 15,500 2 19 75.7 1.91 0.22 .075 5,700 2,800 51 3 22.0 256,000 103,000,000 9,300 1 21 89.9 2.46 0.17 .000 5,250 1,870 13 4 20.1 243,000 107,000,000 17,400 2 23 73.8 2.12 0.11 4,150 1,600 11 5 1.5 21,000 124,000,000 0 0 0 10.5 3.50 0.09 3,150 6 23.1 272,000 104,000,000 14,700 2 19 52.9 1.36 0.05 6,850 700 2,300 7 23 2 265,000 101,000,000 16,800 2 20 70.4 1.86 0.05 .000 6,350 1,250 68 8 23.6 274,000 103,000,000 8,200 1 10 88.6 2.26 0.08 .000 5,6'0 1,970 160 9 23.2 275,000 105,000,000 16,300 2 21 54.3 1.38 0.05 .000 10,350 6,250 175 10 23.3 270,000 103,000,000 16,100 2 20 41.4 1.07 0.05 .000 8,100 7,650 900 11 23.6 282,000106,000,000 7,800 1 9 50.7 1.26 0.04 10,250 360 12 23.0 292,000 112,000,000 18.700 2 21 54.1 1.30 0.04 .000 3,850 2,000 125 13 23.3 286,000 109,000,000 15,700 2 18 58.0 1.42 0.05 .000 19,800 9,350 190 14 22.2 323,000 129,000,000 16,900 2 20 65.3 1.42 0.04 .000 40,500 29,900 300 15 23.2 340,000 130,000,000 15,600 2 19 62.9 1.30 0.03 .000 40,200 28,800 590 16 23.2 338,000129,000,000 16 900 2 20 64.4 1.33 0.08 .000 42,60034,400 1,250 17 20.5 301,000|130,000,000 8,800 1 11 76.4 1.78 0.80 .000 41,000 28,500 800 18 23.3 335,000427,000,000 16,500 2 21 76.3 1.59 0.10 000 35,200 18,000 64 19 23.1 339,000130,000,000 16,300 2 20 53.7 1.11 0.06 .000 14,400 13,500 185 20 23.2 341,000 130,000,000 16,400 2 21 50.3 1.03 0.07 .000 22,600 14,060 185 21 23.2 334,000 127,000,000 19,500 2 23 52.8 1.11 0.19 .000 24,50018,200 200 22 22.5 331,000 131,600,000 19,900 2 24 55.0 1.16 0.11 .000 20.800 9,700 125 23 23.3 355,000 135,000,000 17,500 2 22 41.7 0.82 0.05 .000 15,200 8,700 58 24 17.5 255,000 129,000,000 0 0 0 32.0 0.88 0.03 .000 8,050; 3,670 97 25 0.0 0 0 0 0 0 0.0 0.00 0.06 14,600 26 0.0 0 0 o 0 0 0.0 0.00 0.06 8,750 27 28 0.0 12.6 0 201,000 0 141,000,000 o 25,800 0 2 0 30 0.0 52.9 0.00 1.84 0.09 0.06 16,500, 24,50011,200 95 29 23 2 347,000 132.000,000 17,200 2 21 81.0 1.64 0.05 000 18,500 9,250 65 30 22.8 344,000434,000,000 27,200 3 34 74.8 1.52 0.05 .000 17,70011,300 74 31 23.3 362,000 138,000,000 16,600 2 22 72.0 1.39 0.06 000 20,100 6,000 92 Totals 603 9 8,124,000 417,700 48 521 1692.1 ....4. Av'gs, 19.5 262,000119,000,000 13,500 1.516.8 1 54.6 1.46 0.11 .003 16,80010,900 ii 1 320 Notes:-Percentage of Bacteria removed, 98.10. Percentage of Filtrate used for washing, 5.1. A 350,000 gallon orifice ring was put in Warren Weir, July 13. Bevel gear on washing apparatus broken July 24. TABULATION OF RESULTS. 179 RECORD OF WARREN MECHANICAL FILTER, For the Month of August, 1898. Hours A. M. o 5 Quantity in Gallons. Wash- ing. Sulphate of Alumina Used. Turbid- ity. Bacteria Per Cubic Centimeter. iate for 24 nding 9.00 Hours Operatic Total Passed. Rate of iltration Jcr Acre Daily. Wash Water. Number f Times. Duration Minutes. Total Pounds. rains Per Gallon. Applied Water Eflluent. Applied Water. Settled Water. Eflluent. OR 0 .s c 1 23.0 350,000 135,000 000 138,000,000 136,000,000 137,000,000 19,300 2 26 110.8 2.22 0.42 48,200 9,050 365 9 23.6 368,000 10,200 1 12 133.8 2.55 0.70 .000 27,500 4,550 51 3 23.2 357,000 19,100 2 23 103.8 2.04 0.35 .000 20,200 7,200 48 4 23.0 357,000 27,300 2 35 75.7 1.48 0.15 .000 16,800 8,450 99 5 23.3 352,000 134,000,000 16,600 2 21 80.7 1.60 .000 22,300 12,200 230 6 23.2 351,000 360,000 134,000,000 135,000,000 19,000 2 23 85.0 1.70 0.80 .000 20,400 13,800 165 7 23.6 8,500 1 10 65.6 1.28 0.26 .000 9,300 6,500 140 8 23.3 363,000 138 000,000 16,300 2 19 82.2 1.59 0.37 .000 11,400 5,300 39 9 23.2 355,000 135,000,000 19,300 2 22 183.3 3.61 0.28 .000 49,400 32,600 1,530 10 23.1 360,000 138,000,000 19,800 2 23 168.0 3.27 0.92 .035 34,400 13,6003,100 11 23.2 359,000 137,000,000 20,300 2 24 135.2 2.64 0.55 .000 18,700 5,400 78 12 23.0 356,000 137,000,000 19,600 2 22 126.8 2.49 0.38 .000 9,550 4,100 69 13 23.2 359,000 137,000,000 136,000,000 139.000,000 19,700 2 21 78.6 1.53 0.31 .000 8,850 4,470 165 14 23.2 357,000 21,100 2 24 95.1 1.87 0.60 .000 15,500 12,100 210 15 23.2 364.000 18,900 2 22 96.9 1.86 0.24 10,300 5,550 35 16 23 2 363,000139.000.000 18,900 2 21 68.4 1.32 0.12 .600 4,800 3,120 86 17 23.2 362,000 138,000,000 18,200 2 21 48.7 0.94 0.15 .000 6,450 5,400 160 18 23.6 360,000 135,000,000 8,900 1 10 43.7 0.85 0.08 .000 7,300 4,850 280 19 23.3 357i 000 136; 000,000 17,200 2 19 68.0 1.33 0.10 .000 10,800 5,700 160 20 23.1 341,000 131,000,000 19,100 2 21 92.4 1.90 0.30 .000 27,300 8,850 340 21 23.1 361,000 138;000,000 21,500 2 25 86.7 1.68 1.75 .400 25,000 22,700 19,100 860 22 23.1 360,000 138,000,000 21,000 2 24 106.9 2 08 0.50 .000 15,800 270 23 22.6 352,000 138,000,000 28,000 3 33 84.7 1.68 0.31 .000 12,600 5,800 21 24 23.2 367,000 140,000,000 18,700 2 21 84.3 1.61 0.26 000 5,600 3 200 26 25 23.3 366,000 139,009,000 14,300 2 18 68.2 1.30 0.18 .000 6,450 1,920 2,600 56 26 23.2 364,000 139,000,000 19,500 2 21 66.6 1.28 0.10.000 2,370 130 27 23.3 369,000 140,000.000 18,000 2 19 57.9 1.10 0.09.000 3,500 2,050 36 28 23.6 369,000 139,000,000 140,000,000 10,100 1 11 63.6 1.21 0.18.000 5,020 4,050 120 29 23.3 368,000 18,200 2 20 72.3 1.38 0.10 3,020 3,440 33 30 22.9 360,000 139,000,000 24,700 3 27 76.8 1.49 0.09.000 1,700 1,370 52 31 23.2 375,000 143,000,000 19,500 2 21 87.4 1.63 0.09 .000 1,520 1,600 65 Tot'Is, 719.5 11,162,000 570,800 60 659 2798.1 Av'gs, 23 9 360,000 137,000,000 18,400 1.9 21.3 90.3 1.76 0.36.016 1 15,100 7,550 290 Notes:-Percentage of Bacteria removed, 98.08. Percentage of Filtrate used for washing, 5.1. 180 REPORT OF RESIDENT ENGINEER,-JEWELL FILTER. CHAPTER IV. Jewell Filter Experiments Description. The Jewell Filter Plant consisted of a settling basin, an open filter, with a sand area of 113 square feet; a device for adding coagulant to the applied water, and arrangements for washing and agitating the bed. The construction of the filter, as well as all connections, is shown on Plates No. 17 and No. 18, opposite page 182. Settling Basin. The settling basin consisted of a space in a circular wooden tank, below the filter proper, which was thirteen feet in diameter inside. This space was seven feet high and held 6,600 gallons, which was equal to the normal flow for thirty-five minutes, when operating the filter at a rate of 105,000,000 gallons per acre daily. The applied water was measured before entering the settling basin by a four-inch meter. As the water entered the basin, it was deflected by a curved iron casting, which directed the current around the wall. Coagulant. A solution of sulphate of alumina, prepared as described in Chapter III,* was added to the water through a pipe, which discharged directly into the current of the inflowing water. The solution was lifted by a small steam pump, from one of the tubs in which it was prepared, to a small tank above the filter. From this tank it flowed through an orifice plate, which controlled the rate and which was changed as desired. A constant head was maintained on the orifice by pumping an excess into the tank and allowing the surplus to run back into the original tub. It should be noted here, that prior to February 15, 1898, the solution of sulphate of alumina was pumped directly into the settling basin from the mixing tubs. Filter. The water passed upward from the settling basin to the filter through a central well, 0.58 foot in diameter, which projected 1.48 feet above the surface of the sand. The main body of the sand was a yellow beach sand, with round grains, from Red Wing, Minnesota. Beneath this sand, there was a four-inch layer of crushed quartz. The total depth of sand, on August 31, 1898, was 4.77 feet. The inflow was controlled by a butterfly valve which was operated by a float in a tank, connected with the water in the filter basin. *See Page 156 DESCRIPTION. 181 The filtered water entered the underdrains through 443 screens be- neath the sand. The top of the screen heads projected one inch above the top of the pipes. The screens were composed of punched plates, having nineteen holes to the linear inch in each direction; each hole being 0.025 inch in diamter. The main collecting conduits, were eliptical in shape and had an area of 0.45 square foot, each; and 46 one-inch pipes were screwed into these at right angles to the same. Screens were screwed into holes tapped in the main conduits, into ells at the ends of pipe; and others were fastened into holes in the inch pipes by clamps, which made them fit tightly. All screens were spaced six inches apart on centers. The screens on the main conduits were'o.i/ foot higher than the others. The total area of the holes in the screens was 1.36 square feet. The collecting pipes were slightly raised above the wooden floor of the filter, and, in order to give them support, small broken stones were laid underneath and around the pipes. A layer of cement was laid on top of the stones, coming close up under the screen heads. The five-inch effluent pipe passed through the settling basin and out at one side; beyond which it connected through gates, with the waste pipe to the sewer, with the wash water pipe, and with a six-inch meter, discharging through a regulating device to a clear water reservoir under the floor. All samples of the effluent were collected from a half-inch tap in the effluent pipe. An inch and one-half steam pipe, also connected with the outlet pipe and was used to supply steam for cleansing the filter. The regulating apparatus was placed over the clear water reservoir. It consisted of an orifice in the bottom of a chamber, which would give the required rate of flow with a given head. When the water filtered through the sand too freely it overflowed into a cup on the side. This cup, by its weight, when full of water, closed a butterfly valve on the effluent pipe. The orifice plate was 9.7 feet below that of the lowest screen in the filter, and 17.0 feet below the level of the water on the filter. Washing. Wash water was measured by a four-inch meter and was delivered to the collecting conduits, from which it passed up through the screens and the bed of sand. The rakes were set in motion at the same time. The muddy water flowed over the staves of the filter and was carried off from the space between the walls of the filter and settling basin by an eight-inch pipe leading to the sewer. The upward current lifted the sand from its original position in the bed and during the early washings several inches were carried over the top of the staves. Occasionally the settling basin was also washed, by allowing the wash water on top of the filter to pass down through the central well, REPORT OF RESIDENT ENGINEER-JEWELL FILTER. 182 and out through an eight-inch waste pipe near the bottom. The shaft, connected with the rake arms, ran down through the well and carried on its lower end a curved iron casting. As the rake arms revolved, this casting turned round and directed the current of the water, rushing down through the well, into all parts of the settling basin and flushed out the mud which had settled there. Agitator. Two beams ran across the filter which supported the gears and shaft- ing and the rake system, which was used to stir the bed. These rakes were made of square bars of iron, four feet long on the long arm, and two feet six inches on the short arm. To the bottom of each of these bars a chain 0.75 foot long was attached. When the rakes hung in a vertical position, the bottom of the chains on the long bars reached to within 2.43 feet, and on the short ones to within 3.59 feet, of the screens. The long rakes were attached to arms which extended nearly the entire way across the filter. The smaller rakes were fastened to short arms, at right angles to the others and near the central well. It was possible to rotate the rakes in either direction, by giving the power to the proper pulley upon the counter shaft. The pulleys were driven by belts from the power shaft at the top of the building and at such a speed that the rakes made about seven turns each minute. Traveling in one direction, the rakes assumed a vertical position and stirred up the bed of sand. When their motion was reversed, they were raised through an arc of about sixty degrees and the lower ends, with the chains, rested on the top of the bed. When rotated slowly in this position, they made furrows about two inches deep in the surface of the sand. This last process was called "Trailing." Operations. The filter was put into service on January 21, 1898, and from Jan- uary 30, it was operated throughout the twenty-four hours. The rate was at first about 85,000,000 gallons per acre daily, but was increased from time to time, until on March 1, 1898, it was about 105,000,000 gal- lons per acre daily, and continued at about that rate during the rest of the experiments. The same sulphate of alumina was used as with the Warren Filter, and the methods of preparing and computing the amounts used were the same as described in Chapter III.* Beginning with March 24, 1898, the coagulant solution was applied during washing for several minutes before the inlet gate was opened. Interruptions in the operations are noted upon the monthly record sheets. *See Page 156. Plate No. 17 CITY OF PITTSBURGH FILTRATION COMMISSION PLAN OF JEWELL FILTER JANUARY 1899 P late No. 18. CITY OF PITTSBURGH FILTRATION COMMISSION ELEVATION OF JEWELL FILTER JANUARY 1899 DESCRIPTION. 183 Sand Used. During the process of washing the finest particles of sand were car- ried to the top of the bed and formed there a fine layer which clogged quickly and shortened the periods between washings. In order to cor- rect this effect, sand was removed from the surface, at the request of the filter company, on the following calendar dates:- February 2,1898,-r| inches. March 2, 1898,- i inches. " 4, " -I " " 4? " -3 " " 5, " - | " 12, " -1 " " 14, " - j " 14, " -" (i 26, " -1J " " 30, " -18 " When the filter was first put into operation the tops of the staves were twenty-five inches above the surface of the sand. This distance was so great that it prevented the current of wash water from carrying the heavier particles of mud over the staves to the sewer. In order to remedy this difficulty ten inches of sand were added to the filter on February 14, and again on March 2, 1898. On March 30, eighteen inches were re- moved and twenty-four inches of coarser sand were added. The results of the mechanical analyses of these sands are given in the following table:- Table A. Mechanical Analyses of Sand Used in Jewell Filter. Calendar Date Effective Uniformity Depth No. of Size, Coeffi- in Remarks. Collection. M. M. cient. Inches. 437 Feb. 2, 1898 " 2, " O.36 1-4 First Consignment. 49i 0-39 i-7 11 ll 45° Mar. 24, " 0.46 i-3 Last " 492 " 24, " o-47 i-3 11 ll 453 " 5. " 0-33 i-5 I 454 ll C( I I (( 11 CC Cl Ci tc 0.41 1.4 6 455 456 0.42 0.40 i-4 i-5 12 18 \ Samples collected by tube from the sand in place. 457 0.42 i-4 24 45 s Cl 11 11 0.42 1-4 30 / 459 0.42 i-4 42 460 " 30, " 0.38 i.3 Surface 461 4 I ll 4 4 0.41 i-4 Just below 18 30 ! Samples collected by tube Cl 44 44 0.42 0.42 J-4 1.4 from the sand in place. 0.43 1.4 42 493 Nov. 15, " ' 0.46 1.4 Average sample, collected after dismantling. VARIATIONS IN THS RATE OF FILTRATION AND IN THE APPLICATION OF COAGULANT. As with the Warren Filter, experiments were made to determine the variations in the rate of filtration and in the application of the coagulant. The variations were much less than those with the Warren Filter. The results of the tests are given in the following Tables, B, C, and D:- 184 REPORT OF RESIDENT ENGINEER,-JEWELL FILTER. Table B. Special Test with the Jewell Filter. Variations in the Rate of Filtration and in the Application of Coagulanty For the 24 Hours Ending p. 00 A. M., April 15, 1898. For the 30 Minutes Effluent Quantity, Sulphate of Alumina Used. Total Grains Bacteria Per Cubic Centimeter. Ending, Gallons. Pounds. Per Gallon. Applied Water. Effluent. 9-i3 A. M. Valve Closed for Washing. Il6 9.27 cc Valve Opened after Washing. 209 9-30 CC 2,620 0.10 0.27 3,850 628 10.00 cc 5,840 0-35 0.42 4,550 169 10.30 6,420 0.28 0.30 . 11.00 cc 5,810 0.27 o-33 133 11-30 cc 5,840 0.25 0.30 12.00 M. 5,2io 0.30 O.4O 3,750 III 12.30 P. M. 5,8io 0.30 0.36 1.00 cc 5,810 0.25 0.30 2,200 87 1-30 c c 5,7oo 0.30 0-37 65 2.00 c c 5,720 0.26 0.32 3,100 2.30 cc 5,76o 0.30 0.36 3-00 5,630 0.27 0-34 2,000 74 3-3° 6,010 0.29 0-34 4.00 cc 5,840 0.27 0.32 2,850 181 4-30 cc 5,890 0.27 0.32 5-oo 5,830 0.27 0.32 2,700 105 5-30 cc 5,78o 0.28 0-34 6.00 cc 5,750 0.28 0-34 3,850 102 6.30 cc 5,66o 0.28 0-34 7.00 cc 5,730 0.26 0.32 2,100 65 7-30 cc 5,66o 0.28 0.32 8.00 5,730 O.29 0-35 3,050 73 8-30 5,730 0.27 o-33 9.00 5,58o 0.27 o-34 3,150 55 9-30 5,770 0.29 0-35 10.00 cc 5,6oo 0.28 o-35 2,300 87 10.30 5,640 0.27 o-33 62 11.00 5,690 0.27 o-33 2,500 11-30 cc 5,6io 0.28 o-35 12.00 Mid. 5,5oo 0.27 o-34 2,750 150 12.30 A. M. 5,78o 0.27 o-33 119 1.00 cc 5,6oo 0.27 o-34 158 i-30 cc 5,5oo 0.25 0.32 3,450 160 2.00 cc 5,56o 0.26 o-33 158 2.30 5,650 0.25 0.31 2.40 cc Valve Closed for Washing. 2-55 cc Valve Opened after Washing. 3-00 3,170 0.24 0-53 2,450 434 3-3° 5,740 0.27 0-33 4.00 5,950 0.29 0-34 2,750 101 4-30 cc 5,56o 0.21 0.26 VARIATION IN RATE OK FILTRATION. TABLE B,-Continued. 185 For the 30 Minutes Ending, Effluent Quantity, Gallons. Sulphate of Alumina Used. Bacteria Per Cubic Centimeter. Total Pounds. Grains Per Gallon. Applied Water. Effluent. 5.00 A. M. 5,810 0.22 0.26 3,000 66 5-30 " 5720 O.27 0-33 6.00 5,950 O.24 0.36 2,300 143 6.30 " 5,690 0.24 0.30 7.00 5,790 0.26 0.31 3,300 146 7-30 " 5,790 0.26 0.31 8.00 5,810 0.25 0.30 3,100 123 8.30 " 5,780 0.26 0.31 9.00 5,430 O.29 0.37 Notes:- Changed from Coagulant Tub No. 2 to Coagulant Tub No. 1, at 9.41 A. M., April 14, 1898. Changed from Coagulant Tub No. 1 to Coagulant Tub No. 2, at 3.31 A. M., April 15, 1898. Table C. Special Test with the Jewell Filter. Variation in the Application of Coagulant, From 6.06 A. M. to i.jo P. M., June 2^, 1898. Effluent Quantity, Alkalinity of Effluent, in Sulphate of Alumina Used. Grains Pei Grains. Per Gallons, Terms of Pounds Gallon, Gallon, Between Calcium Car- Between by Weight, Computed Obser- bonate, Parts Obser- Between from vations. Per 100,000. vations. Observations. Alkalinity. 6 o6 A. M. 1.06 i-74 6.16 2.08 0.46 6.26 " 1.09 1.70 6.36 " 6,270 O.83 1-20 I.34 2.03 6.46 O.83 2.03 6-56 " O.67 2.23 7.06 5,740 O.7O i-35 1-65 2.19 7-36 " 5,9*0 O.9O 2.10 2.48 i-94 8.06 6,010 o-93 0.90 1.05 1.90 8.36 " 6,050 0.88 1.65 1.91 1.96 9.00 4,580 1.09 0-93 i-42 1.70 9.10 1.10 1.69 9.20 i-3o i-44 9-30 " 5,720 o-95 1.32 1.62 1.88 9.40 " 1.10 1.69 9-50 " i-i5 1-63 10.00 5,790 1.02 1.71 2.07 i-79 10.10 1.07 i-73 10.20 1.10 1.69 10.30 " 5,720 1-03 1.83 2.24 1.78 10.40 " 1.07 i-73 10.50 " 0.96 1.86 11.00 " 5,720 0.89 1.71 2.09 i-95 11.10 " 0.96 1.86 11.20 " 0.90 i-94 11-30 " 5,640 0.84 1.83 2.27 2.01 186 REPORT OF RESIDENT ENGINEER,-JEWELL FILTER. TABLE C,-Continued. Time. Effluent Quantity, Gallons Between Obser- vations. Alkalinity of Effluent, in Terms of Calcium Car- bonate, Parts Per 100,000. Sulphate of Alumina Used. Pounds Between Obser- vations. Grains Per Gallon, by Weight, Between Observations. Grains Per Gallon, Computed from Alkalinity. 11.40 A. M. 0-77 2.10 11-50 " O.78 2.09 12.00 M. 5,280 O./O i-74 2.31 2.19 12.10 P. M. o-75 2.13 12.20 0.85 2.00 12.30 " 5,260 0.84 i-74 2.31 - 2.01 12.40 0.65 2.25 12.50 " 0.69 2.20 1.00 5,560 0.70 i-59 2.01 2.I9 1.10 0.70 2.I9 1.20 " 0.70 2.I9 1-30 " 6,290 0.70 i-59 I.72 2.I9 Averages, o-93 I.90 I.90 Notes:-The average alkalinity of applied water during the test, was 2.45. Valve opened after washing at 6.06 A. M., June 23, 1898. Valve closed for washing at 1.34 P. M., June 23, 1898. Coagulant Tub No. 2 was in use during the whole time of the test. Table D. Special Test with the Jewell Filter. Variation in the Application of Coagulant, From 9.00 A. M. August 12, to 4.30 A. M. August 13, 1898. Time. Effluent Quantity, Gallons Between Obser- vations. Alkalinity of Effluent, in Terms of Calcium Car- bonate, Parts Per 100,000. Sulphate of Alumina Used. Pounds Between Oberva- tions. Grains Per Gallon, by Weight, Between Observations. Grains Per Gallon, Computed from Alkalinity. 9.00 A. M. 9-30 " 6,380 1-05 i-i5 10.00 " 6,740 1.20 1-25 10.30 " 4,690 1-05 i-57 11.00 " 4,910 0.90 1.28 IT.3° " 5420 1-05 1.36 3.00 P. M. 38,040 6.85 1.26 3-25 " 0.85 i-54 3-3° " 2,680 0-75 0.80 2.09 1.66 3-40 " 0-95 1.41 3-5o " o-95 1.41 4.00 5,530 1.00 0.80 I.OI i-35 4.10 1.10 1.22 4.20 " I.IO 1.22 4-30 " 6,300 i.t6 0.70 0.78 I-I5 VARIATION IN APPLICATION OF COAGULANT. TABLE D,-Continued. 187 Time. Effluent Quantity, Gallons Between Obser- vations. Alkalinity of Effluent, in Terms of Calcium Car- bonate, Parts Per 100,000, Sulphate of Alumina Used. Pounds Between Obser- vations. Grains Per Gallon, by Weight, Between Observations. Grains Per Gallon, Computed from Alkalinity. 4,40 P. M. 1.10 • . • • 1.22 4-50 " 1.15 1.16 5-oo " 5420 1.20 0.80 1-03 I.IO 5-io " I.IO 1.22 5-20 " 1.20 I.IO 5-30 " 8,580 1-32 0.80 0.65 o-95 5-40 1-3° 0-97 5-5° " 1.40 0.85 6.00 " i-35 0.91 6.10 " 1.18 1.12 6.30 " 9460 1.42 1.80 i-33 0.82 7.00 " 4,650 1-36 0.60 0.90 0.90 7-30 " 6,120 i-44 1.00 1.14 0.80 8.00 " 5420 1.42 0.80 1-03 0.82 8.30 " 6,380 i-45 0.90 o-99 o-79 9.00 " 5,390 i-5o 0.80 1.04 0.72 9-3° " 5,860 i-5o 0.90 1.07 0.72 10.00 " 5,570 i-35 0.90 i-i3 0.91 10.30 " 5,860 i-35 0.80 0.96 0.91 11.00 " 5,830 1.68 0.90 1.08 0.50 11-30 " 5,350 i-35 0.80 1-05 0.91 12.00 Mid. 5,570 1.60 0.90 i-i3 0.60 12.30 A. M. 5,500 i-56 0.80 i.02 0.65 1.00 5,720 1.66 0.90 1.10 o-53 i-3O " 5,130 1.60 0.80 1.09 0.60 2.00 " 5,830 i-5o 0.90 1.08 0.72 2.30 " 5,460 1.60 0.70 0.90 0.60 3-oo " 7,150 1.70 1.10 1.08 0.48 3-30 " 4,800 1.70 0.70 1.02 0.48 4.00 " 5,350 1.76 0.70 0.92 0.40 Averages, i-33 1.11 o-93 Notes:-The average alkalinity of applied water during the test, was 2.08. Valve closed for washing at 3.07 P. M., August 12, 1898. Valve opened after washing at 3.25 P. M., August 12, 1898. Valve closed for washing at 4.35 A. M., August 13, 1898. Changed from Coagulant Tub No. 2 to Coagulant Tub No. i,at 12.36 P. M., August (2, 1898. Changed from Coagulant Tub No. 1 to Coagulant Tub No. 2, at 12.10 A. M., August 13, 1898. BACTERIAL EFFICIENCY AFTER WASHING. Washing the sand in a mechanical filter destroys the compactness of the layers. As a result of this disturbance the bacterial efficiency of the filter was generally low after washing. Samples were collected fre- quently in order to show the effect produced, and the results are given in the following tables. It will be noticed that with large quantities of 188 coagulant the decrease in efficiency is not as marked as with smaller amounts:- REPORT OF RESIDENT ENGINEER,-JEWELL FILTER. Table E. Bacteria in Effluent from Jewell Filter, at Times of Washing. Time. Bacteria per C. C. Remarks. Time. Bacteria per C. C. Remarks. Calendar Date April 19, 1898. Calendar Date :-May 6, 1898. 9.16 A. M. 48 9.06 A. M. 5 11.48 " 62 12.00 M. 6 11.51 " V. S. 2.16 P. M. V. S. 12.10 P. M. 524 V. 0. 2.30 " V. 0. 12.13 " 630 2.36 " 376 12.16 " 560 2-39 " 294 12.20 " 217 243 " 35 12.30 " 122 2-53 " 12 2.00 " 54 3-30 " 5 6.00 " 79 5-oo " 8 7.00 " 4 Calendar Date: -April 20, 1898. 9-04 " 3 3.24 A. M. 59 11.00 " 10 3-28 " V. s. 3-46 " 896 V. 0. Calendar Date: -June 4, 1898. 349 " 665 2.23 A. M. 1 3-56 " 201 2.25 " V. s. 3-52 " 352 2.42 " V. 0. 4.01 " 164 245 " 10 4.06 " 114 2.48 " 9 4.16 " 103 2.52 " 6 5-i7 " 88 3-02 " 4 342 " 1 Calendar Date :-May 3, 1898. 6.02 " 2 9.05 A. M. 29 1143 " V. S. Calendar Date:- -June 5, 1898. 12.05 P- M. V. 0. 5.05 A. M. 1 12.08 " 342 5.08 " V. s. 12.11 " 346 5-2i " V. 0. 12.15 " 86 5-24 " 7 12.25 3i 5-27 " 9 1-30 " 29 5-3i " 6 3-i5 " 18 542 " 6 5-oo " 6 6.21 " 5 7.00 " 7 9.00 " 7 Notes:-V. S., means Effluent Valve Closed before Washing. V. O., " " " Opened after " EFFECTS OF WASHING AND OF TRAILING. 189 TABLE E,-Continued. The following records, relating to the above tests, are copied from the Monthly Re- cord Sheets:- Date, 24 Houts Ending 9,00 A. M. Average Condition of Applied Water. Sulphate of Alumina Used,-Grains Per Gallon. Turbidity. Bacteria PerC. C. April 20, 1898 O.O4 2,750 0-47 May 4, " O.O4 4,090 0.92 May 7, " O.O4 3,060 0.96 June 4, " O.O4 3,020 3-95 June 5, " O.O3 2,300 4-04 MECHANICAL EFFECT OF TRAILING. When the filter had been in operation for a few hours after washing the top layer of the sand became clogged. As a result of this the loss of head increased and when it reached about eleven feet the surface was trailed. By this treatment furrows were made on the top of the sand, and, after trailing, the loss of head decreased materially. The filter was operated without trailing from May 22 to June 7, 1898. When the bed of sand was new, and, to a lesser extent, shortly after it had been cleansed with caustic soda, trailing increased the length of the runs between wash- ings. But when the bed had become clogged after a service of many weeks, the trailing failed to produce the former increase in length of runs. These facts are illustrated in the following table:- Table F. Loss of Head with Jewell Filter before and after Trailing. - - to 1- HI - - >-< to >1 to - ( JO to - to UO to - to - to - Number of Trailing. H< do > to " 10, 6.40 " " 11, " 7, 10.04 " " 7, " 8, 3.06 " " 8, 9, 10.03 P- M. " 10, Aug. 5. 6.45 P. M. Aug. 6, " 6, 5.12 A. M. " " to > to - June 13, 5.32 P. M. June 14, - p^ 0 p - > 'o > > •"1 hH to p CO > £ Valve Opened Began After Last Washing. Calendar Date and Time, 1898. oc b > N <0 to Ln to « Ch Ln > 0 ~ CO < hd > 0 to p ? to i 0 0 > p to Co 0 b to '0 to 00 Ln Ji to 4^ Ch O ' 70 > p b 7d p > 0 H £. 2 2 2 £ * o Ln O O <0 kO Cn Ln "4 O to 0 O do Ln O O' to O Ln 1 1-4 1-( 0' 0 0 ~o 0 ~o 0 0 00^1 0 0 vD O 0 vO OO c>o 1 O £ Before Trailing. r 0 tn (n O p 00 O 'O 8 8 LO b 0 p poo - to bi 000 p 0 p b 0 p 'o p ^b 0 do 0 p p to C>0 "o p jb 00 co do Cn tO tO 4^. Ln p' to O p pS bo O After Trail in g W u 2 3-95 o-95 2.40 1.65 * to 0 ^b to « 00^4 Ln O p to 0 0 0 0 p 0 Co bo 4* 0 O p do to bsdo 0 0 jb to 4k 00 CWD b m Q\Ln 0 O 4>. Ch Ch Ch+- Recovery w H *Notes:-Soda Ash was applied to the filter bed, at 2.35 P. M., August 8, 1898, and effluent valve was opened, at 5.06 A. M., August 9, 1898. 190 REPORT OF RESIDENT ENGINEER,-JEWELL FILTER. The following records, relating to the above tests, are copied from the Daily Record Sheets ;- TABLE F,-Continued. Date, 24 Hours Ending 9.00 A. M., 1898. Turbidity of Applied Water. Sulphate of Alum- ina Used, - Grains Per Gallon. Quantity of Wash Water, Gallons. Duration of Washing in Minutes. March 31 O.5O 0-99 5470 8 April 1 O.l8 1.24 4,48O 6 1 O.l8 1.24 4,670 6 " 4 O.II o-37 4,100 5 " 6 0.07 0-37 4,55° 5 June 14 0.03 i-i3 5,400 8 21 0.65 1.72 7,100 10 August 6 0.80 1-30 6,760 9 " 6 0.80 1-30 6,450 9 " 8 0.37 o-99 7,970 9 " IO 0.92 1-83 11,050 13 " 11 °-55 1.46 9,7io 12 " 12 0.38 i-5o 8,620 11 BACTERIAL EFFICIENCY AFTER TRAILING. The effect produced by trailing on bacterial efficiency is illustrated by the records in the following table:- Table G. Bacteria in Effluent from Jewell Filter at Times of Trailing. Calendar Date, Time. Bacteria PerC. C. Remarks. 1898. May 1, 8.10 A. M. 32 Five Minutes before Trailing. " 1, 8.20 " 27 Trailing. " 1, 8-25 " 133 Five Minutes after Trailing. " 1, 8.30 " 19 Ten Minutes after Trailing. June 13, 8-43 " 21 Just before Trailing. " 13, 8.46 " 20 During Trailing. " 13> 8-55 " 244 Five Minutes after Trailing. " 13, 9.06 " 27 " 13, 12.05 ?• M. 17 June 20, 9-35 A. M. 2l8 " 20, 2.28 P. M. 198 Before Trailing. " 20, 2-33 " I90 During Trailing. " 20, 2-37 " 1,866 " 20, 2.40 " 693 " 20, 2-44 " 260 " 20, 2-54 " 172 " 20, 3-i9 " 253 " 20, 10.12 " 151 Note :-The following records, relating to the above tests, are copied from the Monthly Record Sheets :- Date, 24 Hours Ending 9.00 A. M. Average Condition of Applied Water. Sulphate of Alum- ina Used,-Grains Per Gallon. Turbidity. Bacteria Per C. C. May 1 Windy 5490 O.96 June 13 0.02 12,400 i-33 " 14 0.03 21,200 I-I3 " 21 0.65 25,100 1.72 EFFECTS OF TRAILING AND OF CLEANSING. 191 EFFECT OF CLEANSING WITH SODA ASH. On February 15, and on August 8, 1898, the filter was cleansed with a solution of soda ash and then washed thoroughly. One hundred pounds of soda ash were dissolved and thrown upon the surface of the water. A jet of steam was then applied through the underdrains, until the water in the filter boiled. After boiling for ten minutes, the steam was shut off and the filter allowed to stand until the water became cold. The bed was then washed in the usual manner, but longer and with more water. Just before cleansing the filter in February, ten inches of sand were added to the bed. The bacterial results obtained at this time may have been influenced by the new sand. For this reason only those results are given which were obtained on August 8, 1898. One effect of such a cleansing was to renew the life of the bed in such a way, that the time between washings was lengthened, and trailings became more effective, and a greater number between washings were used. Table H. Bacterial Efficiency with Jewell Filter, at Time of Cleansing with Soda Ash. Calendar Date, 1898. Time. Bacteria PerC. C. Remarks. August 8, 9.26 A. M. 89 8, i-55 P. M. 78 " 8, 2.12 (( Valve Closed. " 8, 2-35 (( Bed Cleansed with 100 Pounds of Soda Ash and Boiled. " 9- 5.06 A. M. Valve Opened. " 9- 5-i7 90 " 9- 5.22 " 98 9- 5-32 728 " 9- 5-42 P323 " 9- 5-57 1-337 " 9- 6.12 1-043 " 9- 7.10 868 " 9- 948 412 Note :-The following records, relating to the above tests, are copied from the Monthly- Record Sheets :- Date, 24 Hours Ending 9.00 A. M. Average Condition of Applied Water. Sulphate of Alumina Used,-Grains Per Gallon. Turbidity. Bacteria Per C.C. August 9 0.28 49400 2.52 SPECIAL, EXPERIMENTS, TO SHOW THE EFFECT OF USING DIFFERENT QUANTITIES OF COAGULANT. Special tests were made during the month of June, 1898, to show the effect which various quantities of coagulant would produce on the bac- terial efficiency of the Jewell Filter. The quantity of sulphate of alumina was varied from zero to four grains per gallon. 192 The results obtained are given in the following table, and are ar- ranged to show the rapidity with which the change in the quantity of coagulant affected the bacterial efficiency:- REPORT OP RESIDENT ENGINEER,-JEWELL FILTER. Table I. Bacteria in Effluent,-No Coagulant Used. Calendar Date, 1898. Time. Bacteria PerC. C. Remarks. June 1, 9.01 A. M. Supply of Coagulant Shut Off, Clear. " i, 9-05 " 15 " 1, 945 " 25 " 1, 10.06 " Valve Closed for Washing. " i> 10.24 " Valve Opened after Washing. " 1, 10.27 " 500 "£ i. 10.30 " 600 Cloudy. " I, 10.34 " 550 " 1, 10.44 " 750 " 1, 11.24 " 600 Note : :-Valve opened after washing, at 10.30 P. M., May 31, 1898. June 7, 8.40 A. M. Supply of Coagulant Shut Off. " 7> 8.50 14 " 7, 9.IO " II Clear. " 7, 10.05 " 572 " 7' IO.4O " 1,050 " 7> 12.00 M. 2,904 Note:-Valve opened after washing, at 6.10 A. M., June 7, 1898. Table J. Bacteria in Effluent, Coagulant Applied at Approximate Rate of Four Grains per Gallon. Calendar Date, 1898. Time. Bacteria Per C. C. Remarks. June 3, " 3, 8.58 A. M. 9.01 " 375 1,200 Began to Supply Coagulant. " 3, " 3, <£ 3, " 3, " 3, 9-i5 " 9-30 948 " 10.03 " 12.00 M. 450 128 94 Clear. 58 3 Note:-Valve opened after washing, at 12.04 A. M., June 3, 1898. EFFECT OF DIFFERENT QUANTITIES OF COAGULANT. TABLE J,-Continued. Coagulant Applied at Approximate Rate of One and One-half Grains pet Gallon. 193 Calendar Date, 1898. Time. Bacteria Per C. C. Remarks. June 11, 9.01 A. M. Began to Supply Coagulant. " ii. 9.08 " 7,900 " 11, 9.20 " 7,982 " 11, 940 " 1,113 " 11, 10.00 " 468 " 11, 10.20 " 328 " 11, 10.40 " 246 " 11, 11-23 " 232 " 11, 12.00 M. 304 Clear. " 11, 2.40 P. M. " 11, 3.08 " 182 Notes:-Valve opened after washing, at 4.55 A. M., June n, 1898. The following records, relating to the above tests, are copied from the Monthly Record Sheets:- Date, 24 Hours Ending 9.00 A. M. Average Condition of Applied Water. Sulphate of Alumina Used,-Grains Per Gallon. Turbidity. Bacteria Per C. C. June 2, 1898 " 3, " 0.04 1,700 0.00 0.06 1,420 0.00 " 4, " O.O4 3,020 3-95 " 7, " 0.02 3460 1.92 " 8, " 0.02 12,000 0.00 " 11, " 0.02 28,300 0.00 " 12, " 0.02 19,500 1.46 T abulation of Results. The tables presented upon the following pages give the results se- cured, by days, also the totals and averages for each month. The results of the chemical analyses are given in Appendix No. 2, page 262 et seq. 194 REPORT OF RESIDENT ENGINEER,-JEWELL FILTER. RECORD OF JEWELL MECHANICAL FILTER, For the Month of January, 1898. Av'gs, o JC co co to re te to te - C C X N C. Ci ! i - c c a -i c. ci 7 c: i; - c c x 'i c oi4- icm Date for 24 Hours Ending 9.00 A. M. 00 <51 P p pl 4- p- 4- p 7- co bi w b b 3 00 00 Hours in Operation. 74,800 598,800 o 1 35,600 31,600 43,^00 52,400 177,000 205,000 36,900 16,500 0 Total Passed. Ct ► 2 000'000'£8 0 82,000,000 68 000,000 90,000,000 84 000,000 86,000,000 89,000,000 90,000,000 85,000,000 0 Rate of Filtration Per Acre Daily. pity in Gall Ci Ci o CH JO 009 97* 005" Ik 0 .00'7 * o oos'z ,0 5,100 0 0 Wash Water. o GO l-l 00 WHOHOHO OOH .-i-i-: : :-i-:-i-: . . .-;-;-;-;-;-;-;-; Number of Times. 16.4 181 0 17 0 17 0 25 59 o o co i ■ : . : : ■ ; : Duration in Minutes. 61.7 O' 00 O' 4- 4- O' O to O' 00 C0 co b C ... ... ::: ... 5.8 0.7 0.0 Total Pounds. Sulphate of Alumina Used. -I 0.00 1.16 1.08 0.78 0.77 0.73 0.52 So 0.30 0.00 Grains Per Gallon. : 0.19 0.25 0.22 0.11 0.08 0.09 0.16 0.19 Applied Water. w a 000' 000' i •" .030 Effluent. E 6 JO 'o co O 12,650 15,000 14,050 6,825 2,600 19,000 20,450 Applied Water. o a w W "n S 'tiled Water. TERIA I Centim 1,977 390 393 554 759 956 • • • : : ci 4- : Effluent. Notes:-Percentage of Bacteria removed, 84.72. Percentage of Filtrate used for washing, 8.8. 'Filter not in operation for the 48 hours ending 9.00 A. M., January 25, on account of repairs to the building. * vVash meter broken; quantity of wash water estimated at 450 gallons per minute of actual washing time. The Jewell Effluent Meter was found to register 2 per cent, in excess and all effluent quantities are the proper percentage less than the meter records. TABULATION OF RESULTS. 195 RECORD OF JEWELL MECHANICAL FILTER, For the Month of February, 1898. Hours A. M. Quantity in Gallons. Wash- ing. Sulphate of Alumina Used. Turbid- ity. Bacteria Per Cubic Centimeter. Date for 24 Ending 9 00 Hours Operati Total Passed. Rate of Filtration Per Acre Daily. Wash Water. Number of Times. Duration in Minutes. Total Pounds. Grains Per Gallon. Applied Water. Effluent. Applied Water. Settled Water. Effluent. 1 4 5 6 7 8 9 10 11 12 13 14 15f 16 17 18 19 20 21 24 26 27 28 20.1 22.6 20.4 22.3 22.0 21.4 23.2 19.4 18.5 22.1 19.5 22.6 17.8 21.2 18'6 20 0 22.9 23.5 23.0 23.5 20.7 22.4 23.5 23.2 23.7 19'4 213,000 98,000,000 195,000 80,000,000 204,000, 92,000,000 228,000 95,000,000 240,000101,000,000 226,000 98,000,000 242,000 96,000,000 201,000 96,000,000 193,000 96,000,000 241,000101,000,000 205,000 97,000,000 198,000 81,000,000 169,000' 88,000,000 204,000 89,000,000 201,000 100,000,000 216,000.100,000,000 225,000! 91,000,000 267,000105.000,000 253,000102,000,000 262,000103,000,000 233,000104,000,000 253,000104,000,000 260,000102,000,000 260,000104,000,000 266,000104,000,000 263,000 105,000,000 221,000105,000,000 *11,200 *18,900 *14,400 * 9,900 *15,700 *19,300 *11,700 *14,400 * 9,900 *14,800 12,100 19,400 21,300 25,700 2,000 17,800 8,300 11,600 8,500 18,300 9,600 8,900 8,400 9,300 14,200 5,200 15,600' 15,200 2 4 3 2 3 3 2 2 2 3 2 4 3 4 "3 2 2 2 2 2 2 2 3 1 3 3 25 42 32 22 35 43 26 32 22 33 28 46 45 36 40 13 18 18 18 19 18 17 26 8 25 24 5 6 8.0 10.7 12 0 14.3 17.2 17.3 11.9 12.4 17.8 14.9 14.2 20.0 24.0 26.5 21.2 17.5 23.9 24.6 20.1 24.0 22.2 25.3 21.9 21.9 21.8 17.6 0.18 0.29 0.37 0.37 0.42 0.53 0.50 0.41 0.45 0.52 0.51 0.50 0.83 0.82 o'92 0.69 0.54 0.63 0.68 0.54 0.72 0 61 0.68 0.59 0.58 0.58 0.56 0.08 0 08 0.09 0.06 0.05 0.05 ... 0.04 0.04 0.14 0.26 0.30 0.48 0.47 0.32 0.25 0.19 0.13 0.09 0.08 0.16 0.15 0.13 0.11 0.08 0.07 0.05 .000 .000 .000 .000 .000 .000 .000 .000 ::: .000 .045 .015 .000 .000 .0^ .000 .000 .000 .000 .000 2,350 2,250 2,775 2,700 1,575 1,425 1,700 3,550 8,025 17,500 25,600 24,150 23,600 । 9,250 ,11,025 7,050 12,025 10,150 12,350 9,400 12,112 7,750 8,600 2,700 2,800 1,725 1,750 1,525 5,375 6,225 10,700 23,200 16,300 8,350 6,875 4,325 6,675 8,375 7,525 5,500 9,175 7,525 150 293 463 481 202 192 175 1,075 383 625 3,831 3,413 512 271 613 134 287 169 305 117 192 153 Tot'Is, 580.7 6,139,000 371,600 69 744 488.8 Av'gs, 20.7 219,000 98,000,000 13,300 2.5 26.6 17.5 0.56 0.15 .004 9,430 7,191 638 Notes:-Percentage of Bacteria removed, 93.23 Percentage of Filtrate used for washing, 6.1. *Wash meter broken; quantity of wash water estimated at 450 gallons per minute of actual washing time. t Filter cleansed,-100 pounds of Soda Ash used with steam. 196 REPORT OF RESIDENT ENGINEER,-JEWELL FILTER. RECORD OF JEWELL MECHANICAL FILTER, For the Month of March, 1898. Av'gs, Tot'Is, 2 C O S ■'"i CTTi 4^ W H O 3 5 ■< S W W H O © 7-W IC H Date for 24 Hours Ending 9.00 A. M. 22.2 688.7 h-HOtOtOtOtOtOtOtOtOtOtOtOtObOtOHjtOtObOtObStOtOtObOtO^ I^WWWWWWWOHiWWWWWWffiCOWWCOWWWWNW® CO H i- W W I O kl H O W H CT Li OS M O ® W bl CT O >£■ C CO W W 21.6 22.4 17.4 Hours in Operation. to CT ~O £ 7,875,000 221,000106,000,000 270,000107,000,000 263,000107,000,000 270,000106,000,000 271,000107,000,000 265,000107,000,000 272,000107,000,000 269,000106,000,000 265,000'105,000,000 273,000107,000,000 265,000107,000,000 190,000108,000,000 264,000105,000,000 268,000106,000,000 264,000105,000,000 267,000105,000,000 268,000 106,000,000 1 271,000108,000,000 232,000102,000,000 225,000104,000,000 | 260,000104,000,000 . 263,000104,000,000 261,000104,000,000 ; 265,000105,000,000 266,000106,000,000 264,000104,000.000 263,000105,000,000 171,000107,000,000 252,000 257,000 1 200,000 Total Passed. Quani s 8 o § 108,000,000 106,000,000 106,000,000 Rate of Filtration Per Acre Daily. city in Gall CO . - .... - ... 55 10,900 39,200 10,600 8,600 8,300 8,400 8,600 8,200 9,600 8,300 16,800 8,300 14,400 4,500 13,600 8,500 13,200 7,900 12,300 15,300 10,600 18,500 16,900 8,700 14,700 12,900 11,000 9,300 9,700 13,800 6,500 9,700 LI,500 Wash Water. GO 2.4 CT tOtOtOtOCOCOtOWrfHtoWWtOCOtOWtOCOt'OCCtOtOtOtOtOtOtOCOWtOtO Number of Times Wa IN 16.7 519 21 16 19 14 16 15 14 13 24 12 20 10 19 12 19 12 17 22 15 27 21 13 19 19 12 13 11 21 tO M M 4^ O< Duration in Minutes. • « * _- . o 3.88 204.0 26.6 31.9 31.8 29.9 24.4 27.5 29.9 30.8 29.3 32.0 24.1 17.6 32.7 31.6 30.8 32.2 32.8 45.9 53.6 71.1 125.4 129.7 58.1 21.5 36.3 35-6 43.7 24.1 tO K GO tO CO O O Total Pounds. UI 7) S S w f-A o - ooo ^'cowtoi-i-ppppopppppppppppp ppp Grains Per Gallon. P § ► o 84 83 85 77 b3 73 77 80 77 82 64 65 87 82 82 84 .86 .18 .62 23 .37 .46 .56 57 .95 .94 .16 .99 O. C: Q WO4- p co 0.05 0.06 0.07 0.04 0.05 0.05 0.06 0.05 0.05 0.08 0.12 0.12 0.11 10.10 0.09 0.08 10.49 [0.90 >.00 2.38 0.90 0.41 0.20 0.17 0.20 0.29 0.50 0.04 0.05 Applied Water. Tur it .001 OOP. P . O P O P . OOOOOO. O O . P O O . O P o 888: 8: 8888: 888888'- 88: 888: 882 • 8 8 Effluent. ■ ? 11,747 4,925 4,475 5,150 3,400 5,100 5,075 5,175 5,700 5,475 6,525 12,025 14,175 12,400 7,350 8,600 9,900 56,000 55,483 23,267 14,400 7,000 4,800 4,750 9,967 16,583 6,125 7,650 7,450 Applied Water. Bac Cubic 1 02 282'S 3,675 4,700 2,425 3,875 3,900 3,450 2,700 4,175 4,800 8,950 7,925 4,720 7,650 9,025 6,667 9,383 6,183 5,275 2,300 2,225 2,200 8,200 8,225 6,425 5,500 Settled Water. - d S & 208 204 100 90 108 89 94 81 94 109 120 202 462 258 339 252 166 269 ,036 642 245 118 216 126 98 27 78 - CT CT Effluent. W w Notes:-Percentage of Bacteria removed, 98.23. Percentage of Filtrate used for washing, 4.3. TABULATION OF RESULTS. 197 RECORD OF JEWELL MECHANICAL FILTER, For the Month of April, 1898. Hours i A. M. Quantity in Gallons. Wash- ing. Sulphate of Alumina Used. Turbid- ity. Bacteria Per Cubic Centimeter. e for 24 Lmg 9.01 Hours Operati otal ssed. te of ration ■ Acre aily. rash ater. mber 'imes •ation inutes. • s . si "I 'd . fl $ plied ater. ttled ater. uent. c a Guq 5^ 3~ o O a 0 £ K] 1 22.1 252,000105,000,000 9,200 2 12 44.6 1.24.0.18.003 8,500 4,625 76 2 23.7 268,000105,000,000 4,000 1 6 25.4 0.660.17.000 5,375 5,225 283 3 21.2 241,000105,000,000 9,000 2 14 15.3 0.440.13.000 5,287 3,575 245 4 23.8 271,0001105,000,000 4,100 1 5 14.3 0.37 0.11 ... 3,667 3,300 162 5 23.7 264,000103,000,000 5,200 1 7 15.4 0.41 0.08.000 2,937 2,185 152 6 23.4 275,000109,000,000] 8,900, 2 12 14.6 0.37 0.07.000 2,512 2,250 113 7 23.7 270,000105,000,000 3,600 1 6 11.9 0.31 0.07.000 2,562 1,725 122 8 23.4 268,000106,000,000 7,900 2 14 13.9 0.36 0.08.000 1,725 1,825 91 9 23.0 269 000108,000,000 5,300 1 6 13.1 0.34 0.07.000 2,112 1,700 91 10 19.8 244,000114,000,000 9,100. 2 13 12.2 0.35 0.05.000 2,925 2,650 160 11 23.8 264,000402,000,000 3,900 1 6 12.9 0.34 0.04 ... 2,917 1,950 67 12 23.4 269,0001106,000,000 10,000 2 12 12.9 0.34 0.04.000 3,037 2,125 124 13 23 6 269,000105,000,000 9,400, 2 12 11.1 0.29 0.04 000 3,575 3,250 136 14 23.7 272,0001106,000,000 6,000 1 7 14.0 0.36 0.04.000 2,537 3,600 115 15 23.5 270,000406,000,000 8,7001 2 13 13.0 0.34 0.04 000 2,980 2,733 134 16 23.7 272,000106,000,000 3,700 1 5 12.8 0.33 0.04.000 2,612 2,817 145 17 23.7 271,000,106,000,000 3,800 1 5 13.8 0.36 0.03.000 1,525 2,000 116 18 23.0 262,000105,000,000 4,300 1 6 17.8 0.48 0.06 ... 2,317 2,000 46 19 15.4 172,000103,000,000 5,500 1 7 10.4 0.42 0.05 ... 2,525 2,025 81 20 23.4 263,000104,000,000 8,800 2 12 17.6 0.47 0.04.000 2,750 2,450 96 21 23.7 271,000406,000,000 5,000 1 6 19.4 0.50 0.06.000 2,162 1,625 34 99 23.2 266,000406,000,000 8,800 2 12 17.9 0.47 0.05.000 1,537 950 25 23 21.5 248,000'107,000,000 8,300 2 11 15.5 0.44 0.04.000 1.425 1,650 45 24 23.7 273,000406,000,000 4,600 1 6 17.6 0.45 0.04.000 2,410 1,150 68 25 23 5 267,000405,000.000 9,200 2 13 25 3 0.66 0.06 ... 7,350 4,000 177 26 23.3 264,000 105,000,0001 13,400 3 17 31.5 0.83 0.20.000 16,00010,300 570 27 23.6 267,000405 000,0001 8-300 2 12 44.6 1.17 0.23.000 18,912 9,850 310 28 23.2 263,000105,000,000 14,200 3 18 45.0 1.20 0.21.001 17,725 9,900 548 29 ^3.5 266,000405,000,000 10,400 2 12 38.4 1.01 0.12.000 10,58710,150 305 30 23 5 267,000105,000,000 11,000 2 14 37.4 0.98 0.09.000 7,812 5,150 124 Tot'Is, 687.7 7,858,000 223,600 49 301609.6 ... Av'gs, 22.9 262,000106,000,000 7,500 1 1.610.0 20.3 0.54 1 0.08.000 I 5,010 3,624 159 Notes:-Percentage of Bacteria removed, 96.83. Percentage of Fillrate used for washing, 2.8. 198 REPORT OF RESIDENT ENGINEER,-JEWELL FILTER. RECORD OF JEWELL MECHANICAL FILTER, For the Month of May, 1898. Date for 24 Hours Ending 9.00 A. M. Hours in Operation. Quantity in Gallons. Wash- ing. Sulphate of Alumina Used. Turbid- ity. Bacteria Per Cubic Centimeter. Total Passed. Rate of Filtration Per Acre Daily. Wash Water. Number of Times. Duration in Minutes. Total Pounds. Grains Per Gallon. Applied Water. Effluent. Applied Water. Settled Water. Effluent. 1 23.5 267,000105,000,000 10,900 2 15 36.5 0.96 .000 5,490 6,250 40 2 23.5 266,000105,000,000 9,500 2 13 36.2 0.950.05 .000 4,380 3,300 56 o 23.5 266,000105,000,000 10,900 2 13 37.91.000.03 .000 3,120 2,620 32 4 23.4 263,000104,000,000 10,500 2 14 34.60.920.04 35.60.930.05 .000 4,090 2,120 36 5 23.5 267,000105,000,000 9,700 2 13 .000 4,020 3,150 10 6 23.5 268,000105,000,000 9,200 2 13 36.7 0.960-04 .000' 3,350 2,100 11 7 23.5 268,000105,000,000 10,100 2 13 36.90.960.04.000 3,060 1,500 28 8 23.5 267,000105,000,000 10,400 2 14 36.7 0.960.05.000 4,720 2,520 35 9 23.5 269,000106,000,000 10,900. 2 14 35.6 0.930.17 13,50011,400 103 10 23.4 267,000106,000,000 11,400 2 15 37.1 0.970.28.000 19,400 8,850 115 11 23.5 266,000105,000,000 10,100 2 13 35.20.930.10.000 8,100 5,070 120 12 23.5 267,000105,000,000 10,200; 2 13 26.10.680.05.0001 4,960 3,520 78 13 23.4 267,000106,000,000 11,000 2 14 24.40.640.07.000 4,310 3,000 63 14 23.5 268,000105,000,000 10,100 2 13 24.2 0.630.04.000 4,510 2,520 50 15 23.5 269,000106,000,000 9,600 2 13 26.40.690.06 000! 7,400 3,250 94 16 23.6 268,000105,000,000 8,200 2 13 31.2 0.81;0.10 - 7,050 130 17 23.6 269.000105,000,000 11,800 2 15 55.5 1.440.20 33,60016,300 770 18 23.5 269,000106,000,000 11,200 2 15 66.6 1.731.20.000 55,000 28,2001,040 19 21 7 248,000106,000,000 19,600 2 30 60.5 1.710.40 .00017,000 9,000 73 20 22.8 257,000104,000,000 16,700 3 23 48.0 1.310.18 .00012,500 4,520 27 21 23.5 268,000106,000,000 10,000 2 14 40.8 1.060.18 .000 12-.700 6,400 85 22 22.5 257,000106,000,000 10,400, 2 14 53.2 1.450.55 .000 22,80015,400 195 23 23.3 268,000106,000,000 14,800 3 20 45.3 1.190.40 .00013,200 5,400 200 24 23.1 267,000107,000,000 15,000 3 20 41.4 1.090.15 .000 13,900 7,400 310 25 23.2 259,000103,000,000 14,700 3 20 54.5 1.470.50 .000119,500 11,600 125 26 22.2 273,000114,000,000 20,500 4 99 45.0 1.150.31 .000 12,500 6,000 102 27 23.2 265,000106,000,000 15,800 3 21 30.80.810.19 .000 6,400 3,890 125 28 23.2 267,000106,000,000 15,400 20 25.50.670.11 .000 3,840 4,170 185 29 23.3 269,000107,000,000 14,500 3 19 25.7 0.670.09 .000 3,410 3,670 285 30 23.5 272,000107,000,000 9,700 2 13 28.9 0.740.10 .000 4,070 2,350 85 31 22.2 265,000110,000,000 14,900 3 19 29.5 0.78 0 05 .000 1,500 1,600 42 Tot'Is, 720.6 8,246,000 377,700 72 508 1182.5 ... Av'gs, 23.2 266,000106,000,000 12,200 2.316.4 38.1 1.00 0.19 .000 10,800 6,240 150 Notes:-Percentage of Bacteria removed, 98.61. Percentage of Filtrate used for washing, 4.6. TABULATION OF RESULTS. 199 RECORD OF JEWELL MECHANICAL FILTER, For the Month of June, 1898. Date for 24 Hours Ending 9.00 A. M. Hours in Operation. Quantity in Gallons. Wash- ) ING. j Sulphate of Alumina Used. Turbid- ity. Bacteria Per Cubic Centimeter. Total Passed. Kate of Filtration Per Acre Daily. Wash Water. Number of Times. Duration in Minutes. Total Pounds. Grains Per Gallon. Applied Water. Effluent. Applied Water. Settled Water. Effluent. 1 16.5 189,000106,000,000 4,600 1 6 5.9 0.220.07 .000 1,960 23 2* 23.7 275,000107,000,000 5,400 1 7 0.0 0.000.04 .010 1,700 1,100 580 3* 23.7 268,000105,000,000 6,800 1 4 0.0 0.000.06 .012 1,420 1,270 420 4 23.1 263,000,105,000,000 15,100 3 21 148.4 3.950.04 .018 3,02c 1,950 20 5 23.0 261,000105,000,000 20,000 4 27 150.5 4.040.03 .000 2,300 175 4 6 22.0 252,000106,000,000 19,300 4 25 72.2 2.010.02 3,540 1,350 5 7 23.0 264,000106,000,000 19,200 4 24 72.3 1.920.02 .000 3,460' 700 16 8* 23.7 269,000105,000,000 6,400 0 o 8.300 16,600 15,700 1 8 0.0 0.00:0.02 .010 12,00010,200 7,400 9* 24.0 264,000:102,000,000 0 0 0.0 0.000 02 .012 23,40025,90012,300 10* 24.0 274,000106,000,000 0 0 0.0 0.000.02 .010 17,40015,500 8,000 11* 23.7 269,000105,000,000 1 11 0.0 0.000.02 .009 28,30034.600 8,600 12 23.2 262,000105,000,000 3 22> 54.6 1.460.02 .000 19,50017.300 700 13 23.2 261,000.104,000,000 3 20 49.4 1.330.02 12,40012,200 60 14 22.3 253,000105,000,000 27,100 6,900 22,000 12,600 43 40.7 1.13 0.03 .000 21,20011,800 420 15 18.5 212,000106,000,000 1 10 52.2 1.720 70 .000 27,90017,200 86 16 23.1 265,000106,000,000 3 29 62.3 1.6510.80 .000 16,50010,800 40 17 23.4 268,000106,000,000 2 15 37.2 0.970.42 .000 7,650 4,420 63 18 3 267,000106,000,000 11,800 2 16 25.9 0.680.21 .000 4,250 3,120 150 19 21.4 250,000108,000,000 19,300 10,700 3 25 29.2 0.820.15 .015 6,150 5,000 225 20 23.5 274,000.108,000,000 9 17 53.2 1.360.40 .011 28,90015,100 320 21 23.4 269,000'104,000,000 12,100 2 18 66.1 1.72 0.65 .012 25,10012,300 185 22 23.2 273,000,109,000,000 12,700 9 19 84.8 2.17 0.70 .000 15,60014 900 63 23 23.0 265,000306,000,000 17,400 3 25 62.6 1.650.42 .000 5,950 3,870 9 24 22.7 249,000.101,000,000 31,300 4 49 60.9 1.710.23 .000 3,500 1,800 13 25 23.5 276,000109,000,000 13,600 2 18 28.0 0.710.12 .000 2,700 2,570 91 26 22.8 266,000108,000,000 25,700 4 34 46.6 1.230.12 .080 4.980 1,770 150 27 23.2 267,000'106,000,000 19,300 3 24 55.1 1.440.11 .000 88 28 23.2 266,000106,000,000 17,700 22 31.0 0.820.07 .000 3,770 3,400 300 29 23.4 267,000105,000,000 276,000109,000,000 11,600 9 15 26.4 0.690.07 .000 6,250 4,470 510 30* 23.5 15,300 2 18 8.6 0.22 0.06 045 11,20010,000 2,800 Tot'Is, 684.2 7,834,000 424,500 69 572 1324.1 --- - - - - - ' - Av'gs, 22.8 261,000106,000,000 14,100 2.319.1 44.1 1.18 0.19.008 11,100 8,750 1,450 Notes Percentage of Bacteria removed, 86.90. Percentage of Filtrate used for washing, 5.4. During the 16 days ending 9.00 A. M. June 7, the filter was operated without trailing between washings. * Omitting days starred, when for experimental purposes low quantities of coagulant or none at all were used, the average bacterial results were as follows:-River water, 10,300; effluent, 155; bacterial efficiency, 98.50 per cent. 200 REPORT OF RESIDENT ENGINEER,-JEWELL FILTER. RECORD OF JEWELL MECHANICAL FILTER, For the Month of July, 1898. Hours > A. M. £ £ Quantity in Gallons. Wash- ing. Sulphate of Alumina Used. Turbid- ity. Bacteria Per Cubic Centimeter. e for 24 ing 9.00 Hours Ope rati otal .ssed. .te of ration Acre ally. rash ater. tuber imes. ation mutes. otal mds. ns Per lion. plied ater. uent. ■ plied ater. ttled ater. uent. S'® PA w Nu ofT Dm in M go 0 <: k P-fe <D > C 1 23.4 269,000106,000,000 15,000 2 18 38.61.00 0.29.060 6,000 9,100 800 2 23.5 270,000106,000,000 12,200 2 16 57.11.480.22.040 5,700' 3,670; 170 23.0 257,000:103,000,000 21,900 4 59 74 62.030.17.000 5,250! 2,450! 32 4 20.2 228,000:104,000,000 18,500 3 24 53.71.650.11 ... 4,150 2,900' 25 5 1.2 14,000108,000,000 0 0 0 3.51.750.09 ... 3,150 ... 6 19.4 215,000403,000,000 23,000 3 31 41.91.360.05 ... 6,850 2,050| 610 7 23.5 263,000104,000,000' 13,100 2 17 44.11.17 0.05.000 6,350! 1,470 240 8 22.8 253,000103,000,000 25,200 4 33 47.51.31 0.08.000 5,650; 5,200' 335 9 23.2 261,000104,000,000 19,800 3 25 49.61.330.05.000 10,350 8,600 430 10 23.3 264,000105,000,000i 17,700 3 20 43.91.160.05.000 8,100l 5,650' 830 11 23.2 255,000102,000,0001 22,500 3 27 38.51.06,0.041 ... 10,250 ... 500 12 23.5 264,0001104,000,000 13,800 2 17 39.31.040.04.000 3,850 1,130 190 13 23.1 262,000105,000,000, 20,700 3 26 39.21.050.05.000 19,800; 7,250 415 14 22.3 237,0001 98,000,000 21,500 3 27 38.61.140.04.000 40,50025,400 480 15 23.1 254,000102,000,000 20,800 3 26 47.91.32'0.03.000 40,20028,600; 490 16 22.5 249,000102,000,000! 20,800 3 27 41.91.180.08.001 42,60032,5001,820 17 23.2 253,000101,000,000 16,400 2 22 50.31.390.80.001 41,000'24,000! 410 18 23.0 251,000101,000,000 19,800 3 27 45.11.260.10.000 35,20016,100 260 19 23.1 255,000102,000,000 21,000 3 27 36.110.990.061.000 14,40012,500! 265 20 23.2 260,000104,000, GOOj 20,400 3 27 38.31.030.07.000 22,600:12,600 240 21 23.4 257,000102,000,000, 14,500 2 18 37.11.01 0.19.000 24,50020,100 205 22 22.7 255,000104,000,000 24,300 3 30 35.10.96 0.11.000 20,80014,800! 130 23 22.7 255,000104,000,000 23,900 3 30 40.41.11 0.05.000 15,200: 7,700: 50 24 23.3 261,000104,000,0001 14,700 2 19 36.00.97 0.03.000 8,050 3,120 59 25 23.4 247,000 98,000,000; 13,000 2 16 54 71.55 0.06' ... 14,60011,800 78 26 23.0 255,000103,300,000; 20,500 3 27 55.61.530.06.000 8,750; 4,650 67 27 22.8 251,000102,000,000' 22,100 3 27 59.21.65 0.091.000 16,500! 5,900 65 28 22.8 249,000101,000,000 20,100 3 26 50.11.41 0.06.000 24,50014,400 910 29 23.1 254,000102,000,000 20,200 3 26 63.41.75'0.05.000 18,500 9,650 45 30 23.2 262,000104,000,000 20,200 3 25 62.81.68 0.05.045 17,70011,000 115 31 23.2 258,000103,000,000 19,500 3 25 59.51.61 0.06.060 20,1001 2,300 52 Tot'Is, 687.3 7,638,000 .577,100 84 765 1423.6 ... Av'gs, 22.2 246,000103,000,000 18,600 2.7 24.7 45.91.31 0.11.008 16,80010,900 345 Notes:-Percentage of Bacteria removed, 97.95. Percentage of Filtrate used for washing, 7.6. TABULATION OF RESULTS. 201 RECORD OF JEWELL MECHANICAL FILTER, For the Month of August, 1898. Date for 24 Hours | Ending 9.00 A. M. Hours in Operation. Quantity in Gallons. Wash- ing. Sulphate of Alumina Used. Turbid- : ITY. Bacteria Per Cubic Centimeter. Total Passed. Rate of Filtration Per Acre Daily. Wash Water. Number of Times. Duration in Minutes. Total Pounds. Grains Per Gallon. Applied Water. Effluent. Applied Water. Settled Water. Effluent. 1 23.3 261,000104,000,000 18,000 2 23 42.3 1.13 0.42 48,200 21,100 485 2 23.4 263,000104,000,000 16,600 2 23 58.2 1.550.701.000 27,500,14,000 185 3 23.4 257,000102,000,000 15,400 2 20 52.5 1.430.35.000 20,200 8,550 170 4 23.5 267,000105,000,000 12,400 2 17 54.7 1.430.15.000 16,80011,300 116 5 23.5 260,000102,000,000 14,400 2 19 43.0 1.16 .000 22,30012,400 710 6 23.4 260,000103,000,000 13,200 2 18 48.4 1.300.80.000 20,400 16,200 245 7 23.5 261,000103,000,000 14,500 2 18 35.6 0.950.26.000 9,300 8,000 190 8 23.1 259,000104,000,000 23,000 3 26 36.7 0.990.37.000 11,400 5,750 155 9 9.1 103,000105,000,000 27,000 1 38 37.0 2.52,0.28.000 49,400 2,720 400 10 23.6 263,000403,000,000 11,000 1 13 68.8 1.830.921.001 34,40012,800 1250 11 23.7 260,000101,000,000 9,700 1 12 54.4 1.460.55.000 18,70011,700 550 12 23.3 262,000104,000,000 19,300 2 23 56.3 1.50'0.38.000 9,550 4,870 160 13 22.8 260,000105,000,000 16,800 2 20 40.6 1.090.31.003 8,850 6,200 305 44 23.3 258,000102,000,000 18,300 2 22 55.0 1.490.60'.000 15,50013,700 280 15 23.4 266,000105,000,000 15,100 2 18 59.1 1.550.24 ... 10,300 4,920 96 16 23.4 265,000105,000,000 18,100 9 22 42.8 1.13,0.12.001 4,800 2,870 115 17 23.5 264,000104,000,000 13,800 2 17 35.9 0.950.15.000 6,450 4,850 250 18 23.7 266,000104,000 000 8,100 1 9 29.9 0.790.08.000 7,300 9,800 425 19 23.4 262,000104,000,000 15,500 2 18 38.0 1.020.10.000 10,800 5,750 260 20 23.4 264,000104,000,000 18,400 2 21 54.5 1.450.301.000 27,300 9,150 370 21 23.3 261,000 104,000,000 19,300 2 21 73.2 1.961.75.000 25,00019,800 540 22 23.0 257,000103,000,000 25,600 3 31 63.6 1.73 0.50.000 22,700 7,100 95 23 23.4 261,000103,000,000 16,500 2 19 58.9 1.580.31.000 12,600 8,250 65 24 23.4 261,000 103,000,000 14,800 2 17 57.6 1.54 0.26;. 000 5,600 3,400 53 25 23.1 255,000102,000,000 20,400 25 55.0 1.51 0.18.000 6,450 3,120 37 26 23.4 261,000103,000,000 14,100 2 16 44.5 1.19,0.10!. 000 1,920 1,620 130 27 23.5 262,000103,000,000 15,200 2 18 45.2 1.210.09.000 3,500 2,750 85 28 23.5 264,000'104,000,000 8,600 1 9 36.8 0.980.18.000 5,020 3,500 94 29 23.5 256,000101,000,000 15,900 2 18 40.0 1.090.10 ... 3,020 2,550 110 30 23.4 256,000101,000,000 14,500 2 17 53 9 1.470.09,-000 1,700 1,400 65 31 21.5 237,000 102,000,000 16,900 3 37 48.6 1.430.09.000 1,520 1,150 39 Tot'Is, 708.7 7,912,000 500,400 61 625 1521.0 Av'gs, 22.9 255,000103,000,000 16,100 2.0 20.2 49.1 1.350.36.000 15,100 7,780 260 Notes:-Percentage of Bacteria removed, 98.28. Percentage of Filtrate used for washing, 6.3. Filter cleansed,-100 pounds of Soda Ash used with steam. 202 REPORT OF RESIDENT ENGINEER,-WORMS TILE FILTER. CHAPTER V. Worms Tire Fitter Experiments Description. Water purification by the Worms Tile Filter was carried out in two separate and distinct stages. The first by coagulation, sedimentation, and crude filtration, and the second by filtration through tiles. Two iron tanks were used, each of which was subdivided by a plate partition. This gave us two systems, alike, but independent of each other. All details and arrangements of this system were as suggested by the company controlling the patent rights and are shown upon Plates No. 19 and No. 20, opposite page 204. In the first test, extending from November 25, 1897, to April 9, 1898, two different methods were tried. In one battery the applied water was coagulated, as well as settled, by the addition of ferric chloride, and in the other the water was simply settled, before passing to the filter tank. In each case the water was metered as it entered the tanks. In the second test, extending from June 12 to August 27, 1898, the applied water was treated with coagulant before passing to each battery. One meter and feeding device for coagulant answered for both sets of tiles, the treated and metered water being equally divided. Coagulating Solution and Apparatus. The coagulant used in the first experiments was a solution of perchloride of iron, having a specific gravity of 1.25. This stock solution was further diluted with water for use, and the specific gravity reduced to 1.07. After the plant was remodeled and during the second test a different coagulant was used. The new solution was made by dissolving an iron ore in 150 Baume muriatic acid. This solution was prepared in small quantities, as required. The ore contained 64.7 per cent, of oxide of iron, 1.78 per cent, of carbonate of lime, 9.87 per cent, of silica, and 23.65 per cent, of water. About two per cent, of the total iron was present as ferrous oxide, the remainder being ferric oxide. The solution, which was a thick, muddy mixture, was added, drop by drop, to the water as it flowed from the meter into the first tank. The dropping apparatus consisted of three glass bottles. The lower one held the iron solution and the other two were reservoirs for water and air, respectively. They were so arranged that a drop of water, falling from the first into the second, displaced an equal volume of air, which in turn caused a drop of the iron solution to fall into the water. Scrubbers. Settling Tanks, No. 3 and No. 4, designated as "Scrubbers," were the ones in which the first step toward purification was carried out. DESCRIPTION. 203 These tanks contained, beginning at the bottom, a layer of bricks, placed on edge about one inch apart, with the open channels converging towards the outlet. On top of these bricks a six-inch layer of coarse stone, the size of ordinary ballast, was placed. Next eighteen inches of screenings, then six inches of gravel, ranging in size from one-quarter to one-half inch in diameter, and finally, three inches of ballast, completed the scrubber. The capacity to the overflow, was 770 gallons. The function of this part of the system, as stated by the filter company, "was to remove all sus- pended matter to such an extent, that the water delivered to the tiles should be clear and transparent; also, to remove bacteria to such a degree, that less than 100 per cubic centimeter would remain in the water applied to the tiles." From the bottom of the scrubber, a three-inch pipe carried the water into the top of the filter tank. Filter Tanks and Tiles. In the filter tank the final step in the purification was accomplished. This tank contained the artificial sandstone tiles, connected with piping, fittings and the valves and gates, necessary for their operation. The tiles were made in Germany and shipped direct for the purpose of these experiments. They were composed of sand and ground glass mixed and bakeci in a mould at about the melting point of glass. In the center of each tile was an open chamber, of about 0.50 cubic foot capacity, into which the filtered water passed. The effluent from each tile fell, without interruption, into a glass cylinder, named the indicator, three inches in diameter, and fifteen inches high, with a bottom of brass plate one-eighth inch thick. In the center of this plate there was a standard orifice, 0.376 inch in diameter, and a scale on the side of the indicator showed directly the rate of flow in "Gallons per Twenty-four Hours." Washing. The filter was washed by a reverse current from an iron tank, holding 350 gallons; the high, water elevation of which was 19.5 feet above the centers of the tiles. This tank was connected to each tile and to the scrubbers and was filled by pumping the effluents from the tiles. Sometimes more wash water was required than the tiles would supply and in such cases the effluents fiom the sand filters were used. When the condition of the water passing from the scrubber became poor, contained flocks, or was turbid; or, when the scrubber became so clogged that it did not supply sufficient water for the tiles, its life was renewed by washing. The inlet and coagulant feed were shut off and a reverse current of filtered water, from the overhead tank, passed through for a few minutes. This was supplemented by washing with a small hose stream of sand-filtered water. When the scrubber was first put 204 REPORT OF RESIDENT ENGINEER,-WORMS TILE FILTER. into service after washing, the rate of inlet water was about 1,300 gallons per tile for twenty-four hours. This rate was gradually increased to the usual amount, of 1,850 gallons, and the scrubber used until it again became clogged, when the process was repeated. To wash a tile, the gate connecting the tile with the overhead tank was opened cautiously and a reverse current of water allowed to pass through the tile. In the earlier experiments it was customary to use one tank full, 350 gallons, for each tile. In the later tests, however, only one-half a tank full was used for each tile. The rate of flow was about 130 gallons per minute. Operations. The successful operation of the Tile Filter depended so largely upon the correct addition of the coagulant that almost constant attention was necessary. The amount of iron solution was varied from thirty to eighty drops per minute, according to the condition of the applied water; very slight change in the turbidity necessitating a readjustment of the drop- per. The water, after being treated with the iron solution and after passing through the scrubber, was required to be almost without opalescence, in order that the effluent from the tiles should be clear. The nicety of this adjustment can be better appreciated when it is considered that, up to a certain point, which varied with the condition of the applied water, the addition of the iron solution would cause a decided improvement. When the proper end point was reached, no opalescence could be detected in the water so treated. If, however, a little more iron was added, not only was the iron solution wasted, but the water so treated became again opalescent. The water in the filter tank, in the first experiment, was always kept at a constant level at the height of the overflow, which gave a head of 2.5 feet on the effluent pipes. In the second test the maximum head permitted was 0.9 foot. In the first instance the effluent valves were regulated so that a constant rate was obtained, as the loss of head in- creased. In the second case, the valves were left wide open and the head in the tank gradually increased to the maximum, as the loss of head increased. As the process of filtration proceeded, the loss of head, which represented the clogging of the tiles, became greater and greater, until a point was reached when practically no water passed through. In actual practice, however, washing was resorted to before this point was reached. Breakage of Tiles. Great care was taken in opening the wash gates, so that a sudden rush of water was avoided. Tiles were frequently broken, however, while washing; in fact, during the last week of the first test, we used only one tile, and we should have been obliged to stop the experiments with P late No. 19. CITY OF PITTSBURGH FILTRATION COMMISSION PLAN OF WORMS TILE FILTER JANUARY 1899 P late No. 20. CITY OF PITTSBURGH FILTRATION COMMISSION 11 ELEVATION OF WORMS TILE FILTER JANUARY 1899 BACTERIAL EFFICIENCY AFTER WASHING. 205 this system, had not new tiles been furnished. It was possible that air collected in the wash piping system which gave an opportunity for a water hammer when the gate was opened, and caused the trouble. This piping was changed, however, July 21, 1898, to overcome this difficulty, and yet after this, two tiles were broken. All the breakage occurred when the tiles had been in use some time and when they had become somewhat clogged. It was noticed that, with the continued use of the tiles, the passage of the water through them became less free, and their bacterial efficiency increased. It is probable, therefore, that the clogging was of a permanent nature, and reduced the size of the passages, and, with this increasing obstruction, the pressure inside the tiles at the time of washing became greater, hence the breaking. As it was, the tiles were broken at about the time when satisfactory bacterial results commenced to be obtained. The following table gives the dates when tiles were broken:- Calendar Date. Tile. January Ci ii, 1898 cc F. 20, D. February 15, cc E. March 22, cc C. April 4, cc A. Of the new tiles, which were put in when the plant was reconstructed, tiles D and E were broken July 15; C on August 15, and B on August 27, 1898. BACTERIAL EFFICIENCY AFTER WASHING. The bacterial efficiency of the tiles after washing is less than at other times, as is shown by the following results, selected for this purpose:- Table A. Bacteria in Effluent from Worms Tile Filter, at Times of Washing. Ti Test with Tile B. Calendar Date, August 26, 1898. Remarks. Test with Tile E. Calendar Date, August 27, 1808. me. Bacteria Per C C. Time. Bacteria Remarks. Per C. C. 3.18 P. M. II V. s. 3-i5 A. M. 7 V. S. 4.I8 cc 494 V. s. 4.18 " 88 V. O. 4.21 945 4.21 " 112 4.24 ii 483 4.24 " 87 4.28 a 242 4.28 " 56 4-38 a ii5 4-38 11 44 4 48 a 77 5.18 " 57 5.18 33 7.18 " 102 7-19 15 9.20 " 77 11.20 20 Notes:-V. S., means Effluent Valve Closed before Washing. V. O., means Effluent Valve Opened after Washing. REPORT OF RESIDENT ENGINEER,-WORMS TILE FILTER. 206 It will be seen that the numbers are low just previous to washing and that they were largely increased after this process. After washing, the high numbers usually extended over a period, not exceeding half an hour, after which the tile reached its normal efficiency. It will be found, how- ever, that when the number of bacteria was too per cubic centimeter, or less, a corresponding decrease in the quantity of filtered water took place. Tabulation of Results. On the following pages are tables showing the daily results, from this filter, secured in both tests. Only the bacterial results are given for the first test and for the first month of the second. The last two tables give the entire results secured during the months of July and August, 1898. The results of chemical analyses are given in Appendix No. 2, page 265 et seq. TABULATION OF RESULTS. 207 BACTERIAL RESULTS,-WORMS TILE FILTER, For the Month of December, 1897. Bacteria Per Cubic Centimeter. Date. 24 Hours Ending 9.00 A. M. Settled Water. Applied Water. With Coagu- lant. Tank No. 3. Without Coagu- lant. Tank No. 4. Tile A. Tile B. Tile C. Tile D. Tile E. Tile F. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 36,000 23,300 17,900 17,250 11,450 28,850 24,400 20,050 21,100 25,700 8,025 16,400 7,800 7,975 15,400 25,475 16,350 11,800 13,700 13,050 7,650 5,025 2,500 2,750 1,900 4,000 3,900 36,000 4,200 12,800 8,000 5,600 24,850 14,225 14,050 13,660 3,675 8,200 4,800 11,375 17,750 9,150 4,000 3,675 6,975 4,675 4,550 850 2,775 700 3,225 26.500 22,300 8,150 12,500 19,950 19,250 31,150 27,550 10,700 5,750 6,000 11,800 22,050 11,350 8,000 13,050 5,950 3,800 2,550 2,600 3,000 3,800 4,300 75,000 11,550 21,700 8,300 3,900 12,410 9,700 11,750 5,950 2,200 2,087 2,450 7,663 5,500 3,875 1,250 1,338 3,800 1,850 1,813 1,050 850 1,150 1,900 1,262 31,150 14,300 6,250 4,950 3,600 8,025 6,300 13,350 7,550 2,150 1,537 1,725 2,700 5,850 3,663 2,000 2,400 3,138 1,825 2,025 800 1,575 1,088 2,475 1,563 36,750 12,600 6,050 4,850 - 4,250 7,825 6,725 13,900 7,238 7,917 2,825 4,250 3,350 6,575 4,575 2,600 3,175 3,862 2,763 1,925 775 1,202 850 1,050 1,250 32,200 13,700 6,350 4,100 6,250 6.975 5i 600 5,450, 3,088 9,950 1,637 1,700 2,963 4,025 4,158 1,650 1,987 3,187 2,712 1,662 1,125 1,025 625 1,062 1,613 33,600 18,900 8,650 5,700 9,400 4,600 9,700 5,450 3,175 925 1,125 1,800 4,675 2,263 1,650 1,988 4,450 3,150 2,275 925 1,137 837 1,900 2,138 33,600 19,200 5,000 8,250 3,800 6,550 6,675 4,150 2,825 1,237 850 1,690 4,350 2,963 2,300 2,263 3,487 2,0/ 0 1,487 750 913 625 1,075 1,650 Av'gs, 14,433 9,157 12,263 8,012 5,280 5,965 4,992 5,434 4,928 Percentages of Bac- teria removed... 36.6 15.0 44.5 63.4 58.7 65.4 62.3 65.9 208 REPORT OF RESIDENT ENGINEER,-WORMS TILE FILTER. BACTERIAL RESULTS,-WORMS TILE FILTER, For the Month of January, 1898. Bacteria Per Cubic Centimeter. Date. 24 Hours Ending 9.00 A. M. Settled Water. Applied Water. With Coagu- lant. Tank No. 3. Without Coagu- lant. Tank No. 4. Tile A. Tile B. Tile C. TileD. Tile E. Tile F. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 2,000 4,150 1,625 3,675 3,125 3 950 8,675 21,500 12,550 16,175 11,375 16,125 30,987 40,350 45,325 21,275 22,700 11,000 12,300 19,000 20,450 23,750 26,150 12,650 15,000 14,050 6,825 2,600 1.250 '850 1,350 1,625 3,350 2,675 2,125 1,875 1,950 1,825 5,300 4,200 15,750 26,300 16,000 10,600 8,050 6,600 3,950 13,600 24,100 15,400 12,100 10,200 6,500 2,150 1,650 3,225 2,200 3,250 3,500 2,900 13,600 23,700 575 500 800 787 1,287 1,237 1,250 825 1,000 425 1,152 1,200 2,925 14,900 4,600 2,650 2,625 2,950 1,500 4,850 11,700 4,900 4,400 7,200 2,500 700 625 388 375 480 1,450 800 1,375 1,075 1,100 775 850 2,000 3,325 11,725 6,050 3,875 3,575 1,800 875 6,850 12,775 7,150 3,500 8,700 5,300 675 825 537 500 375 1,325 1,150 1,200 975 800 53/ 837 1,625 2,875 14,200 6,100 3,275 3,250 2,575 1,225 5,250 875 950 700 1,175 1,950 1,987 3,275 4,350 5,687 4,550 4,900 9,150 8,150 13,500 16,075 19,600 13,500 7,450 1,875 1,167 1,575 1,775 1,675 2,087 2,450 3,500 5,650 3,650 2,537 4,850 8,450 16,800 7,600 7,250 2,725 3,150 3,075 4,450 7,300 5,750 3.425 1 800 1 575 875 975 725 400 938 1,000 1,763 2,625 3,275 3,037 3,800 Av'gs, 15,333 7,680 3,055 3,364 2,472 6,546 4,116 Percentages of Bac- teria removed... 49.9 80.1 78.1 83.9 57.3 73.2 TABULATION OF RESULTS. 209 BACTERIAL RESULTS,-WORMS TILE FILTER, For the Month of February, 1898. Bacteria Per Cubic Centimeter. . Date. 24 Hours Ending 9.00 A. M. Settled Water. Applied Water. With Coagu- lant. Tank No. 3. Without Coagu- lant. Tank No. 4. Tile A. Tile B. Tile C. Tile D. Tile E. TileF. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 2,350 2,250 2,775 2,700 1,575 1,425 1,700 3,550 8,025 17,500 25,600 24,150 23,600 9,250 11,025 . 7,050 12,025 10,150 12,350 9,400 12,112 7,750 8,600 400 900 2,050 1,550 1,950 300 1,250 1,300 1,800 200 6,100 5,800 4,300 2,450 1,900 2,200 2,350 13,000 3,050 5,150 5,300 9,200 . 658 1,400 800 350 375 475 50 575 425 1,000 125 350 500 205 350 875 2,250 125 600 825 3,175 800 537 875 375 800 625 450 277 200 275 126 375 '1,025 613 850 425 325 750 4,625 300 675 1,175 1,975 275 675 1,375 725 625 600 525 350 425 500 525 5,550 350 525 700 500 675 625 3,575 325 500 650 3,076 550 650 900 725 750 350 300 850 1,125 Av'gs, 9,430 3,295 738 802 1,028 Percentages of Bac- teria i emoved... 65; 1 92.17 91.50 89.10 210 REPORT OF RESIDENT ENGINEER,-WORMS TILE FILTER. BACTERIAL RESULTS,-WORMS TILE FILTER, For the Month of March, 1898. Date. 24 Hours Ending 9.00 A. M. w Bacteria Per Cubic Centimeter. Applied Water. Settled Water. Tile A. Tile B. Tile C. Tile D. Tile E. Tile F. With Coagu- lant. Tank No. 3. Without Coagu- lant. Tank No. 4. 1 6.125 7,150 5,150 2,675 6,500 2 7,650 4,600 2,025 2,775 3 7,450 3,800 521 560 636 4 4,925 2,650 628 749 868 5 4,475 1,300 182 266 220 6 5,150 2,750 161 253 400 7 3,400 8 5,100 4,100 231 148 9 5,075 1,500 169 246 470 10 5,175 7,000 198 209 281 11 5,700 2,750 79 107 246 12 5,475 6,100 200 13 6,525 1,850 54 84 107 14 15 12,025 2,650 110 70 174 16 14,175 5,000 150 90 270 17 12,400 3,000 110 175 18 7,350 1,650 150 122 175 19 8,600 6,700 285 191 480 20 9,900 72 86 21 22 23 56,000 24 55,483 33,250 301 4,660 25 23,267 4,550 546 1,022 26 14,400 1,600 170 178 27 7,000 3,250 166 102 28 4,800 29 4,750 400 107 137 30 9 967 5,200 151 133 % 31 16,583 2,150 420 332 Avgs, 11,747 4,790 465 633 789 Percentages of Bac- 96.04 93.28 teria removed... 59.2 94.61 TABULATION OF RESULTS. 211 BACTERIAL RESULTS,-WORMS TILE FILTER. For the Month of June, 1898. * '- • Bacteria Per Cubic Centimeter. Date. 24 Hours Ending 9.00 A. M. Settled Water with Coagulant. Applied Water. Scrubber No. 3. Scrubber No. 4. Tile A. Tile B. Tile C. Tile D. Tile E. Tile F. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 12,400 21,200 27,900 16,500 7,650 4 250 6,150 28,900 25,100 15,600 5,950 3,500 2,700 4,980 3,770 6,250 11,200 530 690 275 570 210 620 240 380 640 255 72 100 59 65 120 280 600 670 680 1,030 305 190 105 380 810 750 350 65 120 94 140 420 235 680 905 525 870 960 580 1,670 1,340 2,730 520 260 255 79 79 440 220 330 200 395 1,260 840 1,030 1,000 850 820 330 290 385 95 25 20 82 210 270 285 280 405 720 395 810 600 525 890 1,990 1,130 260 110 88 34 106 120 240 275 215 465 1,530 450 930 910 660 800 770 1,110 405 365 170 38 30 160 125 290 135 355 1,070 540 670 820 550 990 560 900 690 270 175 72 39 75 190 335 140 395 1,120 550 710 1 080 550 790 1,010 900 395 140 52 12 150 61 205 205 140 350 Av'gs, 12,000 339 413 687 471 498 513 471 468 Percentages of Bac- teria removed.... 97.18 96.56 94.28 96.08 95.85 95.73 96.08 96.10 212 REPORT OF RESIDENT ENGINEER,-WORMS TILE FILTER. RECORD OF WORMS TILE FILTER, For the Month of July, 1898. i I SgggSgg^gg^SSe^KSSggfigccooooo.^wtOM 1 Date for 24 Hours [ Ending 9.00 A. M. 8 i . 00 CT 4^. IO CT M CT 00 O 00 00 CT b? O O CO 05 -1 CO 00 CT CO tO rO 05 CO 05 00 *. O Hours in Operation. o 2 o -g f> g s to 1 d 1 c & X £ 1 o z o i i grf§g§gl*gooSsoosSOgoMISgMs»g JJ= |&E I Number 4^ ICKC5-^!*i;^HitcOOlO^O'Ol5K»050ICb:--'IOKH'Kk-- ofTimes. 9° s Durat ion i w HH-]c:^o^x-iQocx"qaoc'CWCKO^Wvi<i-i^a)vi^^ Minutes. p *• CiOOtCCO^^OCih-KOi-l^OO^OOfcC-J^QOCiO^h-kOOOxOtCO-qbDK) Total Pounds. A Grains h, W Ci 1 ^ppobo^w^topwpi^w^ow^boitf vicio-l ^ICOO ICOlbOC CCTUI"JOGCCDQ CQ W C WC£ 4-r<4i Per Gallon. o : ooooooooooooooooooooooooooooooo g§SgSgSgghSSS5gg8Egfe£g§ggSShi5gg Applied = Water. s 8 [ ISHiii gSii »i i iiiSi i i SO Effluent. 1 I K^^-^^^K^K^^^SwSaoOCTCTCTOO^CTCTCT 8g8iSSSOliS#i»«O§mg»issO8 Applied Water. Bacte Cubic Ce i 8 rfiiggasiti'ii^ I Wth§m'hsisi§e Scrubber No. 3. g 2 o i gMosisgOsmiifigiiosio^a s i ! OlSSiWSsasigi sgSgmsSSOi S§8 W 1 2 2 s i =rig|g82ggggs|i ISSSSSSgmsl aSi Cl • 213 TABULATION OF RESULTS. RECORD OF WORMS TILE FILTER, For the Month of July, 1898. CD Av'gs, Totals, Date for 24 Hours Ending 9.00 A. M. o <T> g p 0 © !gS!EESgg?g|g|gSgESgggg8g Hours in Operation. 50 aq CD CO i 00 t) a a ! 2 & w g to A O co 00 to 0 1,570 1,180 850 1,270 1,070 910 1,480 1,330 1,130 1,360 1,420 1,410 940 1,030 1,120 300 ? 0 0 0 1,440 2,210 2,000 2,190 2,240 1,780 2,170 2,030 1,900 2,090 tsi 1 ! 3 0 CD § co © 00 © © •si B 0 bO 0 00 © w © oSioiloSSlooooooo8o5§milo§Si; Total Wash Water i CD CL p bO co ©UHOtCMOHM^OCCOCOOMOHWk-tCMMtCOMHM© Number of times. © 0 4 4 8 0 14 6 7 14 5 10 3 0 0 0 0 0 0 0 10 12 10 0 8 14 0 6 6 0 in Minutes. Q * ! WW^PP^P^P^P^MPPPP^PPPPPPP^PPPP ©©bO©^»^©©i-'©^l>^©^l©©bO-qi-'©©©<J^OOCnCH©-lb©>-* Total Pounds. Iron Ore Used. p © ££gge£5egggs:sgg£g:5£^ Grains Per Gallon. p h-* ©©©©©©©©©©©©©©©©©©©©©©©©©©©©©©© Applied Water. w © © ' H¥ »■ i om¥ 8»¥ i > m Effluent. p 00 0 © B-!8 5 U O O> O 01® ff, U *■ CT 01 C ¥8¥¥8¥ii¥s¥¥¥¥i8¥8¥¥¥8¥8¥8¥s¥¥s Applied Water. Bacte Cubic Ce © i « s © 0 shsims^ H H rifwmsom Scrubber No. 4. CO 8 s* rrsr : M ' S g § gg § g g g § Sg g S O © k co © - - «ti, 8i8g¥ss8¥¥ h h otgaims*ms tsi ►U <© CH © SggaSSgggS'11!! grhsSSSMiaaisg •si 214 REPORT OF RESIDENT ENGINEER,-WORMS TILE FILTER. RECORD OF WORMS TILE FILTER, For the Month of August, 1898. 24 Hours LOO A. M. d B £ o co +S Quantity in Gallons. Washings. Iron Ore Used. Turbidity. Bacteria Per Cubic Centimeter. for ngO Hou Open TILES. Total mber 'imes. 9 O 0) CO S o led sr. fl ied s g co TILES. 25 Wash S.Sg 5 £ ft'S sj fl A B C Water flH Q S 5^5 £ A B C 1 22.2 1,150 2,240 1,910 460 1 5 5.4 3.6 0.42 48,200 450 61 72 76 2 19.3 910 1,900 1,720 1,260 3 18 4.2 3.0 0.70 .000 27,500 520 130 190 165 3 12.9 650 1,200 1,100 890 3 14 6.5 7.4 0-35 .001 20,200 650 66 125 104 4 16.0 810 1,450 1,340 1,360 4 20 6.2 5.9 0.15 .000 16,800 640 79 125 130 5 14.7 790 1,410 1,260 580 2 8 9.6 10.5 .000 22,300 190 220 130 160 6 7.2 380 590 610 1,310 4 19 5.3 10.8 0.80 .002 20,400 34 34 29 7 16.9 830 1,500 1,440 870 2 12 4.8 3.9 0.26 .001 9,300 410 53 103 76 8 19.5 950 1,610 1,840 450 1 5 5.9 4.7 0.37 .000 11,400 155 35 16 43 9 18.4 900 1,780 1,670 740 2 11 7.1 5.7 0.28 .001 49,400 325 93 190 105 10 21.6 1,170 2,230 1,920 440 1 5 9.0 6.2 0.92 000 34,400 210 91 106 31 11 10.6 460 860 760 1,780 5 29 4.2 5.4 0.55 .001 18,700 170 84 99 77 12 20.0 940 1,730 1,550 920 2 12 5.1 4.3 0.38 .000 9.550 105 49 55 44 13 22.6 1,130 2,090 1,890 460 1 6 4.8 3.4 0.31 .006 8,850 15,500 50 13 17 16 14 17.7 780 1,360 1,260 1,640 4 22 5.0 4.4 0.60 .001 195 22 38 49 15 20.3 960 1,550 1,420 1,250 3 17 5.4 4.3 0.24 10,300 4,800 305 26 37 24 16 7.4 280 380 390 1,210 3 18 3.8 8.2 0.12 .001 400 36 57 30 17 7.9 450 680 2,220 5 27 2.6 4.2 0.15 6,450 500 100 100 18 21.3 1,270 2,090 910 3 11 4.3 3.2 0.08 .66b 7,300 540 180 315 19 21.1 1,310 2,150j 1,200 4 15 2.2 1.7 0.10 .000 10,800 940 480 510 20 11.5 730 1,170; 910 3 12 4.2 6.0 0.30 .000 27,300 25,000 980 560 690 21 13.6 480 870 1,380 3 17 4.5 8.6 1.75 .010 105 43 18 22 23.0 900 1,830 280 1 4 4.1 4.1 0.50 .010 22,700 180 26 25 23 21.0 740 1,450 950 3 12 4.5 5.4 0.31 .000 12,600 88 31 33 24 19.1 820 l,570( 590 2 8 4.2 5.2 0.26 .000 5,600 6,450 78 45 46 25 21.1 910 1,620] 1,000 3 12 3.9 4.3 0.18 .000 295 20 18 26 20.6 750 1,470 1,050 3 12 2.4 3.0 0.10 .000 1,920 345 41 54 27 16.9 620 1.250 830 3 12 3.0 4.1 0.09 .000 3,500 115 52 74 28 29 30 31 Totals, 464.4 22,07040,030 22,080 26,940 74 363 132.2 1 Av'gs, 17.2 820 1,480 1,380 1,000 2.7 13.4 4.9 4.5 0.39 .001 16,900 345 99 120 72 . Percentages of Bacteria removed 97.96 99.41 99.2999.57 TABULATION OF RESULTS. 215 RECORD OF WORMS TILE FILTER, For the Month of August, 1898. s 1 Totals, Date for 24 Hours Ending 9.00 A. M. 0>oK>ooo-ioao^?>o>o.^®oo1fc-w>atoo,!O^«1 Hours in Operation. i s : : : : ~ hu sgsgmggagigsgjgggggggggas a § 1 1 mi MI s h n 2 Q > I ii 11 um.sgs.Imsmsi.stii.> Bi I § : : : : to to >-> to w o to to h* o co to >-* w m to >-* w t-* o co to w W o >-* Number of times 1 s : : : : S oo co co ttx o oo to o K -q to >s. to to -q S os to © X a o -q in Minutes £ ! i i i Total Pounds Used. 1 g i Grains Per Gallon. 0.39 .001 = i LllliyiIlIHIi?IIi§IlL!ilL H H Hiihsisr §i Hio§l?§§i§r Water. Effluent I s 8 I , : : , «-,„S8BSSr.^5SwSS®K.S8SSS® ■ h • JgggHlSiigSsllgJHSSsssSgs Applied Water. Cubic Ce t Lj d § I i H i SSsstalgfih^SSsIgpi gsggg Scrubbe No. 4. ► 1 3 5 1 i J 3 i H H §£g£2s = £sggjggssl§^^ d 1- LI f * J? H S2SsssglslisagsSSfeSggg£S§is = ? • &£5ooggSgisi$8?$Sg§s£ES8feK8§£ M 1 REPORT OF RESIDENT ENGINEER,-BOILER EXPERIMENTS. 216 Boiler Experiments. CHAPTER VI. Description. It was originally intended to supply the filtered water to the boilers at the Brilliant Pumping Station. Certain obstacles were found, how- ever, which made this impracticable. Later, the Oil Well Supply Com- pany kindly loaned new boilers for the purpose of an experiment and three of twenty-five horse-power each, were set up in a shed, annexed to the filter building. They were operated as follows:-No. i, with the effluent from the sand filters; No. 2, with the effluent from the mechanical filters ; and No. 3, with unfiltered river water. The boilers, which were of the locomotive type, with a steam dome near the fire box end, are such as are used generally in the oil well regions. The following are the principal dimensions, as obtained from the trade catalogue:- Horse Power ("Oil Country" Rating) 25 Horse Power (Rating at 12 sq. ft. H. S. per H. P.) 30 Diameter 40 inches. Length 14 feet Height 8 " Number of three-inch tubes 48 Length of tubes 96 inches Heating Surface 369 square feet. Length of Furnace 50 inches. Width of Furnace 40 " The boilers arrived about the middle of May and were placed in ser- vice June 5, 1898. The gas was supplied through a four-inch line, about 400 feet long, from an eight-inch main in the Pumping Station yard. The pressure was maintained at about eight ounces, by a regulator placed in the building. A three-inch pipe from the regulator passed to each gas meter, and, thence, a one and one-half-inch pipe to each boiler. Each burner consisted of a two-inch pipe, placed at right angles to the axis of the boiler and in the front part of the fire-box, a few inches above the grate. This pipe was perforated with three rows of three-eighths-inch holes, which were spaced from one-half to three-quarters of an inch apart. One row of holes was placed on top of the pipe and the other two, each one inch from this; there were 147 holes in all. A mixer, placed in front of each boiler, regulated the supply of gas and air; the latter being drawn in by a steam jet from a one-half-inch pipe. The gate was covered with a piece of sheet iron, with fire clay placed over the same, to make it tight. The gas was burned with a blue flame, as far as possible, and if any odor was noticed coming from the stacks, more steam was put on. It was en- deavored to maintain a constant supply of gas at the rate of about twentv cubic feet per minute. Water was supplied to each boiler through a three-quarter-inch pipe; FORMATION OF SCALE. 217 No. I and No. 2 were filled by injectors, the first lifting about ten feet through about fifty feet of pipe with many bends, and the second doing somewhat less work. The suction pipe for the injector to No. 2 Boiler was connected with the outlet pipe from each mechanical filter; so that the effluent from either, alone, could be used, if that from the other was for some reason objectionable. It was also possible to supply both of these boilers with the small pump, in case the injector failed to work. This hap- pened very frequently at first. Later, however, injectors of a larger size were used with better results. Boiler No. 3 was supplied from the city main at about 140 pounds pressure. Formation of Scale. The boilers were drawn off occasionally, in order to observe their condition in regard to the formation of scale; sometimes by blowing off hot and sometimes by allowing the pressure to lessen and the water to cool before emptying. We found that the first method gave us a better chance to distinguish the scale and determine its characteristics; the latter allowed some of the salts to go back into solution and some of the mud to settle down to the bottom, and the scale was not as firmly baked on. For this reason, at the times upon which samples of the scale were col- lected and observations made, the first method of drawing off was adopted. On August 10, 1898, all the boilers were emptied; the gas was shut off at 3.30 A. M., and the pressure gradually reduced to twenty pounds, at which time the boilers were blown off. At 10.00 A. M. the boilers were opened, hand-holes removed, and an inspection made. The best observa- tions were made, however, some few hours later after the inside surface had been given a chance to dry. Samples of scale were collected at this time from the same place on the crown sheet of each boiler, the area of each being about sixteen square inches. Samples were also collected of the material which had oozed through the hand-holes, in Boilers No. 1 and No. 2, placed just under the flues at the smoke-box end; also one from the side of the fire-box on Boiler No. 3. The following table shows the analyses of these samples as reported by the Chemist: - Results of Chemical Analyses of Boiler Scales, Collected, August 10, 1898. Items. Number of Sample, i Parts by Weight. 6 2 3 4 5 Weight in Grams . 19.88 40.02 29.91 .... Calcium Carbonate • • 33-H 17.78 32.11 . 3-79 7-36 1.82 Calcium Sulphate • • 5203 56.98 4746 3-77 30-23 2.38 Magnesium Carbonate • i-99 3.21 1.96 0.00 i-54 0.70 Sodium Chloride .. 0.00 0.00 0.78 88.32 53-82 0.00 Iron & Aluminum Oxides. . .. 2.76 5-2° 1.64 0.40 2.20 85.86 Insoluble Matter . . IO.II 16.83 16.05 372 4-85 9.24 Totals .. 100.00 100.00 100.00 100.00 100.00 100.00 218 REPORT OF RESIDENT ENGINEER,-BOILER EXPERIMENTS. Samples Nos. 1, 2, and 3 were collected, respectively, from the crown- sheets of boilers having these numbers, and indicate the character of the formation with the different waters. As far as observation could deter- mine, the thickness of the scale in each was about 1-32 inch, but the weights, as given, would show that the scale in Boiler No. 2 was thicker than that in either of the other two. Notes taken at the time of collec- tion show that scale in No. 1 was "hard and tenacious." In No. 2, "hard, brittle, and cracks off easily." In No. 3, "soft and powdery." The Chem- ist also states that in grinding up the samples, No. 2 was found to be the hardest. Samples No. 4 and No. 5, from the hand-holes, show large amounts of sodium chloride, which evidently precipitated out of solution at this place, where the water was cooler than elsewhere. Sample No. 6 was collected from the side of the fire-box of Boiler No. 3, where a heavy granular layer was noticed on the vertical plate. The boilers were finally blown off August 29, 1898, and by the in- spection then made the scale seemed to be about the same as before. They were then returned to the owners, who made a very thorough exam- ination and collected samples of scale. The samples were analyzed by the Chemist and the results are given below:- Results of Chemical Analyses of Boiler Scales, Collected, September 17, 1898. Items. Parts by Weight. Boiler and Sample Number, i 2 3 Calcium Carbonate •••• 53-21 27.42 3-34 Calcium Sulphate .... 13.06 53-88 o-75 Magnesium Carbonate • • • • 25.33 12.58 11.06 Sodium Chloride • • • • 5-74 1.64 0-39 Iron & Aluminum Oxides .... 1.42 3-64 16.66 Insoluble Matter . ... 1.24 0.84 67.80 Totals .... 100.00 100.00 100.00 Sample No. i was collected from sides at the bottom of Boiler No. I. Sample No. 2 was collected from the crown-sheet of Boiler No. 2. Sample No. 3 was collected from the bottom and mud ring of Boiler No. 3. As these samples were not taken from the same place in each boiler a comparison is somewhat more difficult than before. We have, however, the benefit of the rigid inspection made by a practical boiler man, and, by the kindness of the Oil Well Supply Company, are privileged to give ab- stracts of the report of their expert upon the condition of the boilers :- CONCLUSION. 219 Boiler No. I:- "The crown-sheet is covered with hard scale, the sides for about half way up are covered with a sand scale of about -J inch in thickness. There is very little sediment in the mud ring, but little of the scale having dropped off. What there is, is of a decidedly sandy nature. The stay bolts and rivet heads in the bottom are thickly covered with sand. Stay bolt braces and rivet heads in top are in good condition. The tubes, as far as we can see, are in fair condition." Boiler No. 2 :- "The crown-sheet is coated with about 1-32 inch of hard scale; the sides and bottom, also the rivet heads, are covered with a very rough coating; the rivet heads being badly corroded. There is very little sedi- ment in the mud ring. Stay bolts in bottom are slightly coated, while those at the top are in good condition. The tubes are covered with a sandy, hard coating." Boiler No. 3 :- "The crown-sheet is covered slightly with a soft scale, the sides are covered with a sand and mud scale, varying from | to | inch in thickness,, but this is loose and can easily be removed; there already being a consid- erable amount of same in the mud ring, which has dropped off. The stay bolts and rivet heads around the bottom are thickly covered with a loose mud sediment; the stay bolts, braces, and rivet heads above the crown - sheet are in good condition; the tubes are slightly coated." General:- "In our opinion Boiler No. 3 is in the best condition; for while there is considerable scale and sediment, it is soft, adheres loosely, and can eas- ily be washed off and removed. The other boilers we would consider on a par; the only difference being that the rivets in No. 2 are badly cor- roded and the tubes have a thicker coating than either of the others. Con- sidering all things, we believe this boiler to be in the worst condition of the three." CONCLUSION. We have, then, in conclusion, that filtration of the Allegheny River water removes the mud and insoluble matter which would, by depositing,, cause the boilers to be frequently cleaned and washed out. The incrust- ing properties which remain, while they may not make a scale as quickly or as thick, as if greater amounts of other material were present, yet,, when the deposit is formed, it is hard, of a character which gives it the name of "porcelain scale," and difficult to remove except by tools. The results of the chemical analyses of the various samples of boiler waters will be found in Appendix No. 2, page 315. These samples were always collected from the blow-off pipes, and, when the recorded tempera- REPORT OF RESIDENT ENGINEER,-BOILER EXPERIMENTS. 220 ture is not at or near the boiling point, it means that the boiler, from which the sample was collected, was out of service at the time. Additional reports and tables relating to various parts of the work are appended. Respectfully submitted, Morris Knowles, Resident Engineer, December 28, 1898. APPENDICES TO Report of Resident Engineer, Nos. l"6e EXHIBIT 5. REPORT UPON Methods of Chemical Analyses and Discussion of Results, BY Dr. WALTHER RIDDLE, CHEMIST. APl'EXDIX No. i. APPENDIX No* L Mr. Morris Knowles, Resident Engineer, Pittsburgh Filtration Commission. Sir :- I beg to submit herewith my report upon the methods, and a discus- sion of the results, of the chemical analyses made for the Filtration Com- mission. The results have been reported to you from time to time during the progress of the work. PART I. Methods. The methods of chemical examination will be described in the same order as that in which the results are given in the tables, in Appendix No. 2. The solutions used will be mentioned in each case before the de- scription of the method of analysis. Collection of Samples and Preliminary Examination. Half-gallon acid bottles were used in which to collect the samples. These held the amount necessary for examination, with a small margin of surplus. The collector noted upon the label the place, time of collec- tion, temperature of water, and in the case of the river, gate chamber, and settling basin samples, after May 17, 1898, the result of the observa- tion of the turbidity. For those samples, the turbidity of which was not determined at the time of collection, a comparison was always made with standards graded as follows:- ;T Turbidity. Sediment. i. Clear. 1. None. 2. Very Slight. 2. Very Slight. 3- Slight. 3- Slight. 4. Decided. 4. Decided. 5. Very Turbid. 5. Heavy. 6. Muddy. 6. Very Heavy. Any odor was noted and described. COLOR.* Solutions. The standard solution whose color was 5.0, was prepared as follows :- 1.246 grams of potassium-platinum chloride, containing 0.5 grams of platinum and one gram of cobalt chloride (crystallized), containing 0.25 *Allen Hazen, American Chemical Journal; Vol. XIV, 1892. 226 APPENDIX NO. 1,-REPORT OF CHEMIST. gram of cobalt were dissolved in 200 c. c. (1:1) of hydrochloric acid and the solution made up to one liter. By diluting 1, 2, 3, 4, c. c., etc., up to 50 c. c., in Nessler tubes, color standards of 0.1, 0.2, 0.3, 0.4, etc., were obtained. Method. After a scale had been made, as described above, 50 c. c. of the sam- ple under examination was placed in a Nessler tube. The color observed, upon looking down through the tube at a white porcelain plate, was com- pared with the standards until a corresponding color was found. Fractional standards were also found to be useful. NITROGEN AS AMMONIA. Solutions. I. Nessler's Reagent:-To prepare this solution, 35 grams of potas- sium iodide and 13 grams of corrosive sublimate were placed in about 600 to 700 cubic centimeters of water and heated to the boiling point. When everything was dissolved, a cold strong solution of corrosive sublimate was added, until the color of peroxide of mercury became per- manent. One hundred and sixty grams of potassium hydrate were then added and the solution diluted to one liter. 2. Standard Ammonia:-This was made by dissolving 3.15 grams of ammonium chloride in one liter of water. This gave a strength of one milligram of ammonia to each cubic centimeter. A weaker solution was made by diluting the above solution to one-hundredth of the original strength. For very delicate work this may be diluted again; although when the one-hundredth solution was used and run in from a good burette, fractional parts were very readily determined. 5. Caustic Permanganate:-To prepare this, 200 grams of stick caustic potash and 8 grams of permangante of potash were dissolved in one liter of water. The solution was then boiled down, to about one-half its original bulk, in order to remove all traces of ammonia. On cooling, it was made up to one liter again with distilled water, free from ammonia. 4. Carbonate of Soda:-With acid waters it was necessary to add a few cubic centimeters of a saturated solution of carbonate of soda, before determining the ammonia. Apparatus. In our laboratory a large eight place still or condenser was used for making the ammonia distillations. The apparatus consisted of a copper tank, surrounding eight block tin worms, which at the upper end were connected with the distilling flasks. The lower ends were at such a height from the table that Nessler tubes were easily set under and withdrawn. COLOR-AMMONIA-NITRITES. 227 Method. i. Free Ammonia:-Five hundred cubic centimeters of the water to be tested were placed in a one liter glass flask, and after connecting the lat- ter with the condenser it was boiled over a Bunsen burner. The first three tubes full of distillate were set aside and nesslerized. The result obtained gives the "Nitrogen as Free Ammonia." One more portion of 50 c. c. was distilled and discarded. 2. Albuminoid Ammonia:-The distillation was now stopped for a time, then 50 cubic centimeters of the caustic permanganate solution were introduced into the flask and the operation continued. Three portions were again caught and nesslerized for "Albuminoid Ammonia." Nesslerizing. To the glass containing a portion (50 c. c.) of the distillate, two cubic centimeters of Nessler's solution were added, and the color ob- tained, after standing ten minutes, was compared with standards also treated with two cubic centimeters of Nessler's solution. A fresh scale of standards was generally made for each set of distillations. NITROGEN AS NITRITES. Solutions. 1. Nitrite:-A standard nitrite solution was prepared by dissolving 0.406 gram of silver nitrite in boiling water. Sodium chloride was added until no further precipitation of silver chloride occurred, and the solution was then made up to one liter. One hundred cubic centimeters of the clear supernatant fluid were drawn off and diluted to one liter. One cubic centimeter of this solution, which was further diluted for use, is equal to one-hundredth of a milligram of nitrous acid. 2. Color:-The solution for obtaining the color with the nitrous acid, which may be contained in a sample of water, was made up after the method described by Leffman, which is a modification of Greiss' method.* (a) 0.5 gram of sulphanilic acid was dissolved in 150 cubic cen- timeters of dilute sulphuric acid. (b) 0.1 gram of naphthylamine was boiled with 20 cubic centimeters of water. The colorless solution was decanted and mixed with 150 cubic centimeters of dilute sulphuric acid. The two solutions (a and b) were then mixed. *"Examination of Water"-3d, Ed. 1895, Page 44-Henry Leffman. 228 APPENDIX NO. I,-REPORT OF CHEMIST. Method. Fifty cubic centimeters of the samples were placed in a Nessler tube and one cubic centimeter of the solution (2) was added. After standing twenty minutes a comparison was made with the standards. NITROGEN AS NITRATES. Solutions. 1. Sodium Hydrate:-This was prepared by dissolving 100 grams of sodium hydrate in a liter of distilled water; when the hydrate was dissolved a good sized piece of aluminum foil was dropped into the vessel. It was generally found necessary to weight the foil with a glass rod to keep it on the bottom of the containing vessel. When the aluminum was completely dissolved the solution was boiled down, until about one- half of the original bulk remained. Upon cooling, it was again made up to one liter. This solution was thus made free from nitrates. 2. Aluminum Foil:-This was used for generating hydrogen, by reacting with the caustic solution to reduce the nitrates to ammonia. Method. Two hundred cubic centimeters of the water were evaporated down to one-third of the original volume, with ten cubic centimeters of the caustic solution in a porcelain dish. On cooling, the liquid was decanted into a salt-mouth bottle of a little over 200 cubic centimeters capacity. The bottle was filled up to the 200 cubic centimeter mark and a piece of aluminum foil added. This was allowed to stand uncovered over night and the next morning 50 cubic centimeters were withdrawn and nessler- ized. The amount of nitric acid was calculated from the amount of ammonia found. During the early part of our work we distilled before nesslerizing, but this was found to be both inconvenient and unsatisfactory. It was found to be unnecessary under ordinary conditions to keep the bottles corked over night. We tried connecting a thistle tube which was filled with broken pumice soaked in dilute hydrochloric acid. By many comparisons with standards, the open bottle method proved its superiority. chlorine. Solutions. 1. Silver Nitrate:-This was prepared by dissolving 4.79 grams of pure silver nitrate in one liter of water. One cubic centimeter of this solution will precipitate one milligram of chlorine as silver chloride. 2. Potassium Chromate: -A solution of potassium chromate of a strength of about 5 grams to 100 cubic centimeters of water was used as an indicator. NITRATES-CHLORINE-SOLIDS. 229 Method. One hundred cubic centimeters of water to be tested were placed in a porcelain dish, to which a few drops of the chromate solution were added. The silver nitrate solution was run in from a burette until the red color of silver chromate appeared. RESIDUE) ON EVAPORATION. Method. Both "Filtered Solids" and "Unfiltered Solids" were determined in all samples, which showed any considerable amount of suspended matter. The sample was thoroughly shaken in the bottle; 100 cubic centimeters were then withdrawn and evaporated to dryness in a weighed platinum dish over the water bath. After drying in this manner, the dish, with residue, was placed for ten minutes in the air bath, which was held at 1040 C. to remove the last traces of water. The weight of this residue in milligrams gives the "Unfiltered Solids" in parts per 100,000. For "Filtered Solids" 100 cubic centimeters were evaporated in like manner after having been passed through a double thickness of best German filter- paper. The difference between "Filtered" and "Unfiltered Solids" gives the result for "Suspended Matter." For a long time, the results for "Filtered Solids," obtained by this method, were unsatisfactory. As an example:-although it was known that the hardness of the Allegheny River water was increased in passing through the sand filters, a corresponding increase of solids in the effluent, over those in the river water, was not observed. Upon investigation it was found that the best filter papers contained enough soluble matter to vitiate the results. One hundred'cubic centimeters of distilled water took up, on an average, one part per 100,000, in passing through double papers. After the papers had been washed with 150 to 200 cubic centimeters of this water there was no increase. As a matter of safety, therefore, we washed the papers thoroughly with distilled water and afterwards passed about 100 cubic centimeters of the sample through, before a portion was taken for evaporation, and after this we had no trouble. EOSS ON IGNITION. Method. After the determination of "Filtered Solids" the dish was heated over a Bunsen burner to a faint red heat and the loss in weight noted in milligrams. 230 APPENDIX NO. I,-REPORT OF CHEMIST, Solution. Standard Soap: -A solution of castile soap in 35^ alcohol was balanced against a standard solution of calcium carbonate, contain- ing one milligram of carbonate of lime to the cubic centimeter. As 100 cubic centimeters of distilled water will produce a lather only after about one cubic centimeter of soap solution is added, a correction had to be made for this. The soap solution was standardized, so that 100 cubic centimeters of solution containing 10 milligrams of carbonate of lime required 11 cubic centimeters of the soap solution. Then in each case the number of cubic centimeters of soap solution minus one gives the "Hardness," expressed in parts per 100,000. Method. One hundred cubic centimeters of the sample were placed in a glass stoppered bottle, of about 250 cubic centimeters capacity, and soap solu- tion was run in slowly with frequent shakings of the bottle, until a per- sistent lather was formed. There are many objections to the soap method of determining "Hard- ness." It is perhaps not to be commended for accuracy, but where experi- ments are undertaken with a view to ascertaining the suitability of a water supply for household purposes, the effect upon the soap consumption is a matter of great moment. This is especially the case in a city like Pitts- burgh. ALKALINITY. Solution. Sulphuric Acid:-A fiftieth normal solution of this acid was used. One cubic centimeter of this solution will neutralize one milligram of calcium carbonate, and the results are therefore reported in parts per 100,000 of this carbonate. Method. One hundred cubic centimeters of the sample were placed in a 200 c. c. porcelain dish, to which a drop of methyl orange indicator was added. The -o add was then run in drop by drop from a burette, until the yellow color of the methyl orange just began to turn pink. The great advantage of the methyl orange is that the determination may be carried out in the cold. SULPHURIC ACID. Solutions. Barium Chloride :-A solution containing 100 grams of this salt to the liter is used. HARDNESS, HARDNESS-SULPHURIC ACID-IRON-ALUMINA. 231 Method. Two hundred cubic centimeters of the sample, which must have been fil- tered if not already clear, were used for the determination. Two cubic centimeters of the barium chloride solution and a few drops of hydro- chloric acid were added and the solution evaporated in a beaker on the hot plate, to a small bulk, or until the barium sulphate was completely precipi- tated. The precipitate was filtered, washed, ignited, and weighed as barium sulphate and the sulphuric acid calculated from the result. IRON. Solutions. i. Standard Iron:-This was prepared by dissolving 0.7 gram of ferrous ammonium sulphate in water, which was acidified with sulphuric acid and then oxidized with permanganate of potash and finally diluted to one liter. The strength was therefore one-tenth milli- gram to one cubic centimeter. Another standard was made by diluting the above named solution ten times, which gave one one-hundredth milligram to one cubic centimeter. 2. Sulphuric Acid:-A 30^ solution of this was prepared. 3. Thiocyanate .--A solution containing 50 grams to the liter of potassium sulphocyanate was used. Method. One hundred cubic centimeters of the sample were first evaporated to dryness and then taken up with dilute hydrochloric acid, after which a little permanganate was added. The excess of hydrochloric acid was boiled off and 5 cubic centimeters of sulphuric acid (30^ solution) with 15 cubic centimeters of thiocyanate were added. This solution was then diluted to the original volume (100 c. c.). The depth of color of the sample, after the above treatment, was compared with standards treated in the same way, until a good match was found. ALUMINA. Solutions. 1. Alum:-A standard solution was made up of such strength, that each cubic centimeter contained one milligram of oxide of aluminum. Portions of this solution were readily diluted, so that each cubic centimeter contained one one-hundredth milligram of alumina. 2. Logwood:-This was prepared by making successive infusions of logwood chips. The first four were decanted and discarded and the fifth was saved for use. It was generally found better to prepare a fresh solution for each set of determinations. 232 APPENDIX NO. I,-REPORT OF CHEMIST. Method. Five hundred cubic centimeters of the water were evaporated to small bulk and placed in a Nessler tube. If necessary this was diluted to the mark, and then one cubic centimeter of logwood solution was added. The color obtained was compared with standards similarly treated. This method was found to be somewhat erratic. The color was often brought out by the addition of a few drops of acetic acid. DISSOLVED OXYGEN. Solutions. i. Manganous SulphateThis was prepared by dissolving about 30 grams of the salt in the least quantity of water. 2. Sodium Hydrate:-A saturated solution containing about 10 grams of potassium iodide to 100 cubic centimeters was used. 3. Sodium Thiosulphate: -For titrating the liberated iodide a one-hundredth normal solution was used. Method. The sample was collected in a bottle of about 250 c. c. capacity, which was carefully calibrated, and the temperature of the water at time of taking the sample was noted. With a small pipette one cubic centi- meter of the potassium iodide solution was added; then one cubic centi- meter of the manganous sulphate solution was run in carefully with a pip- ette and the bottle was shaken up. The liberated iodine was titrated with the thiosulphate solution. Results were calculated to milligrams of oxygen per liter and were reported in percentages of the amount held by distilled water, saturated with air at the same temperature. A table giv- ing the quantity of dissolved oxygen in water saturated with air for the temperatures from 32°F. to 36°F. was used. PART II. Discussion. In the tables, found in Appendix No. 2, the results are grouped according to the locality at which samples were collected. In regard to the general character of the Allegheny River and Monongahela River waters the following may be stated:-The appear- ance of the waters changes very quickly after rains, as is shown by the figures in the column headed "Turbidity." The dissolved solids vary according to the height of the rivers. After heavy rains the amount of solids in solution is small. The color of the river water has generally been due to suspended matter, though, occasionally, dissolved color has been found which has not been removed by filtration except with the use of coagplant. DISSOLVED OXYGEN-DISCUSSION. 233 Chlorine is always present, the Allegheny containing more than the Monongahela. At some points on the Allegheny, Montrose Pumping Station in particular, the chlorine figures were frequently very large. This is probably not due to sewage contamination, as the free ammonia is not correspondingly abundant, but to subterranean waters. On drilling the well at Brilliant, salt water was found at a depth of 141 feet. The Allegheny and its tributaries drain the oil country where, in drilling for oil, salt water has often been found. The Monongahela River water contains large proportionate amounts of sulphuric acid, due to the mine waters discharged into it by the Youghiogheny River, Turtle Creek, and other streams. The water at Twenty-ninth Street, where we obtained our samples never gave an acid reaction with methyl orange. The fact that the Monongahela River is slack water has a great bearing upon its chemical character. During long dry spells, the flow of water from the mines being practically constant, the water in the pools formed by the dams becomes very acid. During the time in which the Filtration Commission has been making observations, we have had no very protracted dry spells, and we have not been able to test the Monongahela water when in this peculiar condition. As a rule, the Allegheny River is less heavily charged with organic matter than the Monongahela. At Brilliant, on the Allegheny, we have found a variation of from 0.0042 to 0.0360 parts per 100,000 of nitrogen, as albuminoid ammonia. The nitrogen as nitrates shows a variation of from 0.0018 to 0.2100 parts per 100,000. Nitrogen very seldom occurs as nitrites showing that oxidation is very complete. The percentage of saturation with oxygen of the samples of water collected from the gate chamber of the sand filters which corresponds to the river water, has always been high. Very respectfully, Walther Riddle, Chemist. November 30, 1898. DBSCR I PTC ION OF Sources of Samples AND Results of Chemical Analyses, ALSO Number of Bacteria per Cubic Centimeter. APPENDIX No. 2. APPENDIX No. 2. In this appendix a short description is given of the sources from which samples were collected, followed in each case by a table of the results of the chemical analyses. The last column of the tables shows the number of bacteria per cubic centimeter, counted in the correspond- ing bacterial sample, collected at the same time. In the case of the samples collected from the gate chamber, settling basin, and effluents from filters, the number of bacteria given is the average for the twenty- four hours ending 9.00 A. M., of the date following the calendar date given in the second column. The statements about the sources of the samples, not collected at the experimental filter plant, were obtained from the officials in charge of the various works. In addition to those samples relating directly to the filter experi- ments, others were collected occasionally, of the water supplies of Pittsburgh, Allegheny, and of some of the neighboring places. It was desired especially to learn about the character of the water obtained from the various cribs in the Allegheny River. A study of the results given in the several tables will show to what extent these devices changed the character of the river water, and it may be readily seen that, in general, the effluents from the cribs were clear and nearly free from suspended matter, except after an occasional very muddy period of the river; that the number of bacteria in the same was usually less than in the river, and that the hardness of the water from the cribs was materially greater than that of the samples of river water. It should be noted, in exception to the above, that the effluents from the cribs at Montrose and Millvale differed but very little, in regard to the items mentioned, from the river water. ALLEGHENY RIVER AT BRILLIANT. Samples of the "Allegheny River at Brilliant" were collected about once a week, from the beginning of the work until March i, 1898; for the next three months samples were collected twice a week, and after June 1, 1898, samples were again collected once a week, until the close of the experiments. Additional samples were occasionally collected, for the special determination of the "Suspended Matter," and the turbidities were observed by the stick scale method at the same time. The results of the analyses of these special samples are given last. 238 APPENDIX NO. 2. The water supply of Wards 1-23, inclusive, of Pittsburgh, is obtained from the river at Brilliant Pumping Station. The intakes to the pump wells are three 36-inch pipes and one 48-inch pipe; the former being 180 feet long and the latter 230 feet. The outer ends of these pipes are protected by timber cribs, which are covered with "T" rails, spaced four inches apart, and riprapped with stone. The samples were collected, sometimes from a boat in the stream over the intake, but more often from the current passing by a raft of logs, moored to the bank, about 800 feet above the pumping station. Allegheny River at Brilliant. (Parts Per 100,000.) 346 373 405 194 272 303 OS I .33 .41 .51 59 5 11 22 ■27 Serial Number. *sStAy Oct. 11 " 18 " 25 Av'gs, Sept. 2 " 23 " 30 Aug. 24 Av'gs, tO^H co co CO Av'gs, - - - S CO O O' to to M 00 W Cn QO Date of Collection. 22<5^ £ "°S- • Dec'd Slight V.sl'gt Slight Dec'd Slight Mud'y Dec'd Turbidity. k co k k w O Q O w £ to O CR CR Color. b bob OC^ Cn 00 O .0133 b bb tO f- 05 to Q5 g .0210 .0307 o o o o Ci to >-1 bo CR to CO to O to Oi Q .0137 b b b b 4- 00 4k 4k O O O O Albuminoid Ammonia. Nitrogen as, £100' 888 co oo o .0019 888 co toom .0023 .0034 b b b b o o o o 05 i-' H-* On ow^o .0006 b b b b o g g o o o o co Free Ammonia. .0000 .0000 .0000 .0000 JL .0000 .0000 .0000 1 .0001 .0000 .0001 .0001 .0001 .0000 .0000 .0000 Nitrites. s g bo .0675 .0750 .0225 .0650 .0825 .0487 .0638 .1050 .0106 .0092 .0018 .0075 .0240 .0175 .0170 .0180 Nitrates. 3.55 3.45 4.44 2.70 2.27 3.31 2.43 tc o co 3.13 1 tO 4^ CO k k k CO O CO CR O 2.40 3.60 1.80 160 2.60 Chlorine. 17.6 18.4 17.0 13.1 10.4 14.0 14.8 CO O p co CO CR 5 S CO Ci 4^ 14.1 21.6 11.2 11.2 112.4 Total. Residue on Evapora- tion. 1.0 11.1 4k H P p W do b do b Suspended. o 7.2 6.8 5.0 4.9 3.8 5.6 5.2 5.0 -I 6.4 7.4 6.0 8.5 5.6 Ci 03 CR ^4 4^ Ci Ci O Loss on Ignition. 5.49 CH CR CR k CR k to IO co 5.03 4^ CR CR O CR CR H Qi 4- 5.41 5.84 4k 05 05 05 05 io to co 0 0-40 7.65 Mi. -J o O> b bo b ?-* o o o c> Total Hardness. CR S OOO bow 05 h-* O _ 4.63 CO CT 4^ GO 4^ CR CR CO CR 8 6.08 ... 8.00 6.50 3.75 Alkalinity. w .. 1.75 2.51 2 68 1.82 1.30 12 82 2.33 bo o 1.33 1.65 0.93 1.41 Tr. 1.40 b b b b on to c© on Sulphuric Acid. .046 .062 .032 .044 .063 .044 .060 .086 8 .184 .003 .070 .480 Iron. 1 49,500 14,000 75,000 59,500 9,402 15,645 3,160 Bacteria Per Cubic Centimeter. RESULTS OF ANALYSES. 239 Allegheny River at Brilliant. (Parts Per 100,000.) 717 737 756 769 774 624 637 663 681 697 ci CT CT CMCI CO to Cl CT CT 4. 4" 4*. 4k 05 4 CO CO Cl 05 COOO4M Serial Number. » Av'gs, - - - to to to H* ' 00 ct 4* 4- - J Av'gs, 1898. Jan. 3 " 10 " 17 " 24 " 31 Av'gs, Dec. 6 " 13 " 28 Av'gs, 1897. Nov. 1 " 8 " 11 " 15 " 23 " 29 Date of Collection. V.sl'gt Slight (( c ( u V.sl'gt Slight Dec'd Slight Slight V.sl'gt q®Lq, p, p bi Turbidity. to h-' .20 .20 .15 .25 .25 .28 .30 .30 .30 30 .20 .30 CO CO CO o o o 8 W 4 4 W b W O O O CT O O Color. 6600' .0052 .0064 .0220 .0096 0064 .0074 c o o o o (X 4- 4*- O OS .0111 .0118 .0110 .0104 O' to .0110 .0120 .0168 0224 0120 .0168 Albuminoid Ammonia. Nitrogen as, .0020 o o o o o o o o o o CO J-L O Q Q Q 0 .0016 88888 to to O to to O 4^ .0015 .0012 .0020 .0014 .0019 888888 o 4 to to to to co to 4- 4k O 4- Free Ammonia. .0000 o o o o o 88888 o o o o o .0000 .0000 .0000 .0000 0000 .0000 .0000 0000 0000 .0000 .0000 .0000 .0000 .0000 .0000 .0000 .0000 Nitrites. .1425 .1575 .2100 .0600 CO GO 04 .0900 .0750 .1200 .0600 .0975 bzor .1650 .0450 .1125 .0700 400000 05 CO CO 05 CT tO CT O O O tO to O O O O CT CT Nitrates. 1.46 1.69 1.31 1.30 1.54 1.44 1.53 2.30 1.91 1.19 0.90 1.33 2.11 to H H bo bo to o o 3.15 4.16 4.41 3.36 3.67 1.78 1.51 Chlorine. 11.9 ooonwS OS O 4 © 00 15.3 ^lOW^W 05 4k Cl Cl to 23.7 CO CO ODO 19.7 18.8 21.6 23.6 21.6 12.4 20.0 Total. Residue on Evapora- tion. 1.4 0.0 4.2 2.0 0.4 0.2 4.8 p to 05 05 O d b to bo b 10.7 31.6 0.2 0.2 2.0 co p bo p p o 4- 4 4- 4 to to Suspended. 4.5 7.2 4.4 4.4 3.2 3.2 5.2 to pi 4- 4i 4k kbbotob 5.5 6.8 1.68 4.4 2.96 5.2 2.09 6.9 3.89 Cl CT Cl CO Cl 00 Cl O IO Cl 4 Loss on Ignition. 2.59 2.63 2.42 2.87 2.84 2.18 2.09 3.14 2.17 1.42 1.64 2.10 2.24 tO tO 4 05 4 CT Co Co 4 io CO 4 O WOOOOtO Total Hardness. 1.73 CH CD GO O 1.48 p Q O tO 00 tO tO O O 00 1.72 1.31 2.53 1.32 3.51 tO tO 05 05 4 CT h b b b ® m 05 CO 00 CO CT 4 Alkalinity. 1.24 4 - - O - 05 4 4 41 -I O 00 Cl SO CT 1.43 2.44 1.47 1.20 0.92 1.13 1.79 H-1 H4 LO co wb CD -J tO 2.47 2.88 3.81 4.00 1.89 1.16 1.06 Sulphuric Acid. .059 .056 .014 .150 .046 .030 to .066 .184 .050 .200 .062 .123 O 4 to CT 4 O 4k CT O .095 4* O 4 o o o 4 02 4k Cl CT C Cl 4k 00 O to Iron. 10,600 to * ^OOlOl : 8888 16,480 1,100 12,800 45,200 20,600 2,700 5,100 8,900 1,300 52,312 155,200 10,900 6,750 36,400 Bacteria Per Cubic Centimeter. 240 APPENDIX NO. 2. Allegheny River at Brilliant. (Parts Per 100,000.) COQOO coooc tMOOOOfDOOOCl ■oooooococococo CO to CT O CO 00 CO CT CT) COCTCDCTCO^ICTOOCT' 000000030000^4^1 i4i4bCtOHOOCO Serial Number. Av'gs, | May 2 " 5 " 9 " 13 " 15 " 16 " 17 " 18 " 23' " 31 Av'gs, tO tO bO CT CT CT cOCitOOOCiCTCOCTCT Av'gs, 1898. i Mar. 4 : " 7 " 11 1 " 14 । " 17 " 21 । " 25 " 29 Date of Collection. - • g .S C 81 5 ' co Q. " ~PQ.ctQ. „ p p p pcra f£ "era -era'2b ~ '00'2115'0 5^8 5* pi 2 <; g 22 < £ Sfo Turbidity. 03 O .25' .25 .30 .25 25 40 .40 .35 .30 .30 .22 .25 1.22 20 .22 .20 .20 .17 .25 .25 bO t O be to to to be to to I O' 0 to to O' O' O' Color. .0164.0015 oooooooooo ohhwwhhiooh OO^OOOtCOCQ GO 8888888888 OQHtObOHHtOHH CO^ObC^bO^OCOQ .0077.0018 .0098.0012 .0054.0020 .0062.0012 .0072.0020 .0042.0020 .0124.0020 .0068.0016 .0084.0032 .0088.0014 .00761.0015 .0042.0018 .0042.0022 .0042.0014 .0062.0012 .0062.0012 .0140.0014 .0096.0018 .0120.0014 Albuminoid Ammonia. Free Ammonia. Nitrogen as, .0000 8888888888 oooooooooo oooooooooo .0000 888888888 OOOOOOOOO OOOOOOOOO .0000 88888888 SSgccpgc Nitrites. .0180 .0300 .0150 .0225 .0150 .0075 .0075' .0075 .0075 0300 .0375 .0458 .0375 .0525 .0450 .0600 .0525 .0450 .0300 .0525 .0375 2 00000000 CO Ct c Cl CO CT Cl CT O W to to 'tol to '7 O Cl Cl Cl Cl O Cl Ci Nitrates. 1.66 1.40 1.35 1.18 1.58 2.92 2.62 160' 1.40. l.OOj 1.53 1.36 bbbbb b b nb 1.29 p p CT CT p p ~ p CD CTO f-1 CT CT CT CO CO-^CTOCOCTCIOO Chlorine. 8.2 8.8 12.0 8.6 11.6 45.9 70.4 21.7 12.1 7.4 9.6 8.5 10.8 8.0 11.2 9.4 10.6 8.6 8.3 P'M to CO 1- ppppppCTO toorf^tocobototo Total. Residue on Evapora- tion. 11.9 CT CT CO p CT CO O CT p p CT p O w w w b> ot io b b io 0.2 popoppopo wioiotobbisHoo CT to ? 9 ? 9 p 0 tOCTCTtCCTbOCTtO Suspended. 3.5 03 4^ 03 03 03 03 t>3 03 bO 03 3.4 ppppopCTbop to CT co to 0 O O O bo 3.2 pppcotococoto CT CO 0 to O) CT IO 2- Loss on Ignition. 2.80 to to to w to co to bO to to CTbobowbo^coococo OQOWOOOCOtOX 2.29 towtoppptototo Hb^ootkeebiob XOO'X^OCjXX 2.72 pppptoppp COCOCOCTCTICTCTtO CTCTCOCTOOCTOCT Total Hardness. 2.13 2.10 2.10 1.70 2.15 2.72 2.82 1.89 1.77 1.81 2.20 1.83 1.30 1.37 1.70 1.90 2.20 1.71 2.00 2.46 1.85 1.75 pppppptoto to O CO CT co co co to CTCiOOtOCTi-OCT Alkalinity. * 1.00 bbl H37 wdb tCQi w 80'1 0.79 1.14 0.61 1.44 1.50 1.47 1.27 1.07 0 44 1.18 p p p p p p p p CT CT Ct CT to Cl ^ 7 CO COCiCictOOOCiCT Sulphuric Acid. .033 16,700 oooooooooo hwwwcwocww CTWCTWOOWCTOO CO CT CT CT jopy-tyo '4OH^)00! to ~CO Go 'tn 88888; 8888 .041 3,472 OOOOOOOOO WWOWOiCTCTWCi 0 0 0 0 0 0 co co to CTO _ppH^CTp4^ co to oGo CO CO CT 00 00 c> ci oi o ci 0 0 0 0 OOOOOOOOO .040 7,679 OpOOOOOO CT CT CT OS to CO to CT CO CT O Ci CT CT Ci Ci .C3C0. pp CT CT Cl CT Ct : -oenCOCT ci 0 : ci 0 0 0 ci p 0 • p 0 0 p p Iron. Bacteria Per Cubic Centimeter. RESULTS OF ANALYSES. 241 Allegheny River at Brilliant. (Parts Per 100,000.) 1254 1284 1314 1344 1376 1161 1186 1207 1236 1065 1084 1109 1135 Serial Number. 'sS(Ay Aug. 1 " 8 " 15 " 22 " 29 Av'gs, Julv 5 "'ll " 18 " 25 Av'gs, 1898. June 6 " 13 " 20 " 27 Date of Collection. 0.26 0.70 0.21 0.11 0.20 0.07 0.07 0.08 0.02 0.08 0.11 0.34 Vsl'gt Slight 0.60 0.09 Turbidity. co .25 .27 .30 .35 .40 to to to to to .25 .22 .30 .30 .20 Color. sow .0120 .0106 .0105 .0106 .0078 8 8822 CO GO O CO O O CO to .0085 .0062 .0100 .0110 .0070 Albuminoid Ammonia. Nitrogen as, .0024.0000 .0030.0000 .0024'.0000 .0022.0000 .0022.0000 0020.0000 0000-Z700' 1 .0020.0000 .004210000 .0018.0000 .0028.0000 .0019.0000 .0018.0000 .0024.0000 .0010.0000 .0024.0000 Free Ammonia. Nitrites. .0435 .0525 .0375 .0525 .0225 .0525 .0694 .0825 .0900 .0525 .0525 .0300 .0375 .0300 .0150 .0375 Nitrates. 2.42 4.10 2.58 2.18 1.56 1.68 2.47 p p p p bo b w b O CH GO o IbO 4^ to 2.78 2.52 1.79 2.60 Chlorine. 19.5 H CO W 00 O b q bo b b 13.1 Si X IC O bo k b A 19.1 8.2 12.4 37.8 18.0 Total. Residue on Evapora- tion. 8.8 tO J-1 p 4^ p p bcobobo 1.4 oowto boiobb 9.0 to M 00 O O tbOH Suspended. 4.2 4i. CO 4^ CT womoo 4.3 p p p b b b bo 4.3 4- 4- 4^ CO CT 00 4- Cl Loss on Ignition. 3.99 co to CO CO CT co co do COOrf-K 4.53 p p p p co do 4^ GO 4^ 00 3.51 CO 4^ CO CO to 2^ 4- to CO © co o Total Hardness. p CH p p p p 4^ o h4 do co b< o to to to o 3.41 CO CO CO tC bi co co to Cl O 00 3.10 p p co to Ohwo O GO O to Alkalinity. 0.93 1.61 0.71 1.20 0.82 0.30 1.55 £6-2 6Z-I 08-1 zro 104 0.88 1.54 0.96 0.79 Sulphuric. Acid. o o .030 .016 .026 .014 .012 .020 o o o o l-J to to O CO CO 4- .010 .006 .006 .020 .010 Iron. 18,300 I-i 4x : p5*5^50 • 8888 11,200 8888 7,400 O' Ct GO p o oi cji o a o o Bacteria Per Cubic Centimeter. 242 APPENDIX NO. 2. Allegheny River at Brilliant. (Special.) (Parts Per 100,000.) oaoiQi CR CO O GO 1100 1105 1106 1107 1119 1120 1147 1127 1146 1156 1015 1013 1017 1014 1018 1020 1030 1034 1035 1038 1039 1040 Serial Number. Av'gs, July 1 " 2 " 3 " 16 I Av'gs, June 14 " 15 " 16 " 17 " 18 " 19 " 20 " 21 c* 2° " 30 Av'gs, 1898 May 18 " 19 " 19 " 20 " 21 " 22 " 24 " 24 " 24 " 25 " 26 " 27 Date of Collection. 0.26 p p p p b< < h- to C7HWP- 0.48 Dec'd 0.90 0.31 | 0.17 Slight 0.60 0.90 0.70 0.16 0.12 0.63 0.13 0.17 0.16 0.45 V.t'd Slight Turbidity. .30 .30 .30 .30 co o OS' Of Z?- OS' eg* OS' os OS' co co w w fo w w w k: • • • ; O O O1 O O< O O Color. :::::::::: Albuminoid Ammonia. Nitrogen as, :::::::::: :::::::::::: Free Ammonia. .0000 .0000 .0000 0000' J ... .0000 .0000 .0000 ::: .0000 ,0000 <0000 .0000 .0000 .0000 .0000 .0000 Nitrites. :::::::::: o : : : : : : co: * ; ; : cr Nitrates. kg'S II 1.10 1.40 1.50 8.S4 2.14 2.72 1.70 1.58 1.60 2.00 3.90 1.94 1.82 ,2.08 2.10 1.02 ... i.io 0.94 1.05 0.72 1.03 |1.18 1.12 Chlorine. co 12.8 11.2 13.2 31.9 9'92 h-4 CO CR CO H-4 j-4 h-4 CO to ^1 CR CR O 4- 4- C IO O o to io bo bo bo o to & 17.5 23.1 14.6 14.3 12.6 26.4 20.5 24.9 20.6 143 18.3 10.7 10.3 Total. Residue on Evapora- tion. co GO MhP WjP- 15.7 16.6 20.9 7.7 5.0 7.3 22.2 40.2 25.0 5.0 6.8 9.4 14.4 6.1 5.7 2.0 1L9 17.5 13.2 6.7 10.7 ; 3 3 3, Suspended. 3.6 3.8 4.0 8.2 1 4.3 5.4 4.6 5.2 4.4 3.9 4.5 3.4 4.0 3.4 4.6 CO GO W W W co W W ili 4k & W W W b5co^biai4^tcjp-4xciccbi Loss on Ignition. 4.13 p CO CO CO b b b to O GO CR O 3.26 3.70 2.48 2.66 1 2 90 3.60 | 4.10 ' 3.36 j 2.95 3.18 3.68 1 2 57 I 2.60 2.60 2.70 3 00 2.42 2.10 1 Total Hardness. CO i 1 3.120.68 3.020.32 2.720.41 3.401.82 I LO cd o co co to co co co to to to co bi c cn to h b *-<i bi h co CO^C^tOMOOOO 1.98 2 04 2.12 1.81 1.96 2.26 1.54 2.00 1.79 2.63 1.81 1.90 1.92 Alkalinity. 1.16 1.58 ... 1.41 1.13 1.23 0 96 1.00 1.13 0.85 Sulphuric Acid. .027 .024 .030 .018, .038' .025 oooooooooo rc - 4-ti CO CO OS CO O' tC Ci Ci O .026 026 .024 .026 .035 .032 .025 .014 Iron. 9,200 4,650 j 1 18,600 4,300 12,000 34,100 9,850 9,850 9,000 7,000 16,600 12,200 6,000 3,350 Bacteria Per Cubic Centimeter. RESULTS OF ANALYSES. 243 Allegheny River at Brilliant. {Special.) (Parts Per 100,000.) 1280 1281 1282 1283 1301 1302 1303 1309 1310 1312 1311 1340 1341 1342 1343 1359 1362 1373 1374 Serial Number. Av'gs, W li IC ti W J co >r oi^WHOcooojHoococosrooi^wM Date of Collection. p 0.18 0.20 0.80 0.24 0.85 0.88 0.80 0.65 Dec'd 0.42 0.14 0.14 0.80 1.20 0.45 0.24 0.15 0.10 0.15 Turbidity. lo .22 JO .22' '.27 .20 .25 .27 .30' .30 .30 .30' .25 *30 .27 40 .40 .40 .35 ■ | Color. • : :::::::::::::::::::: Albuminoid Ammonia. Nitrogen as, Free Ammonia. .0000 0 22222222^00000 Mi 88888888§iii8§; i i i Nitrites. :::::::::::::::::::: Nitrates. £67 0 p p p p HNJOWN>tjpjOW4.WOl4iW cn X Ci 4- 4- --t 5 tx:CT fc bi: C: i:C '1 Oi Cl 2 0 7;. 0 0 IO 0 4^ 0 co 0 0 a co c ts 0 tc tc o tc tc 4- Chlorine. 31.2 I37.5 23.0 210 31.4 20.8 46.4 33.2 45.1 35.2 37.1 21.8 15.4 15.6 78.6 80.6 24.4 21.2 12.4 11.0 12.1 Total. Residue on Evapora- tion. CO 20.0 7.8 4.4 14.6 6.0 29.4 186 32.3 23.0 23.7 10.2 3.7 5.1 69.2 72.6 15.7 11.8 3.4 2.4 3.4 Suspended. 4.0 p JO p p p p p p p p p 00 p p p p p p 4^- p b co -'ioffibbwfwbow'^iirokiQOQobob Loss on Ignition. 4.37 3.11 6.30 6.48 6.60 6.20 4.32 4.18 4.80 3.98 4.00 , 4.00 3.40 4.68 4.90 4.88 318 2.74 1 2.88 , 3.50 ■ 3.22 3J2 Total Hardness. to _tO to P tO P P P P to P to p OS CO 4- 4- 4- 4- 4^. b. b b b c» 0: bi c ic b ic 'i b tc --1 b C X O O OCX OO CIC'I O O4S 0 tc 0 ICO Alkalinity. I 09'1 1.65 2.06 2.31 2 20 2.06 1.54 1.72 1.50 1.53 1.47 1.72 1.54 1.79 1.41 1.62 1.03 0.89 0.96 0.65 0.41 Sulphuric Acid. .015. 010- .010 .011 .018 .020 .020 .016 .026 014 .016 .016 .012' .014| .012 .012 .008 .014 .0181 .0141 .0141 Iron. 18,300 49,700 5,400 5,500 12,600 Bacteria Per Cubic Centimeter. Mineral Analysis. Sample Collected September 19, 1898. (Parts Per 100,000.) Total Solids 12.70 Loss on Ignition 4.30 Calcium Oxide, (CaO) 2.04 Magnesium Oxide, (MgO) 0.49 Sulphuric Acid, (SO3) 1.61 Chlorine, (Cl) 2.20 Silica, (SiO2) 0.10 Iron Oxide, (Fe2O3) 0.01 APPENDIX NO. 2. 244 PITTSBURGH CITY TAP. Samples of "Tap Water" in the city of Pittsburgh were collected about once a week during the months of June to November, inclusive, 1897, and then occasionally until March 1, 1898. All of the water pumped from Brilliant, first passes into the Plighland Reservoir, of about 117,000,000 gallons capacity, and then is distributed over the city. At first these samples were collected in the laboratory of Coster & Riddle, and later, after October, 1897, in a blacksmith-shop in Cherry Alley, near the Public Safety Building. The second sample, dated September 22, 1897, and the one dated September 27, 1897, were also collected at the latter place. Pittsburgh City Tap. (Parts Per 100,000.) S CO O 00 H CCM*- O' 4^ CO IO to 4- 6 14 23 28 Serial Number. Av'gs, Aug. 4 " 12 " 20 " 26 Av'gs, July 7 " 13 " 19 Av'gs, 1897 June 9 " 16 " 24 " 29 Date of Collection. Slight cc 4 C Dec'd Dec'd ll Turbidity. b 00 ... .0205 ... .0144 ... .0182 ... .0181 5 o bob o^o ... .0119 b b b b CO O' GO O O O Color. Albuminoid Ammonia. Nitrogen as, .0019 .0028 .0012 .0017 .0018 w .0020 .0004 .0016 § co .0001 '.0000 .0030 .0000 Free Ammonia. I .0000 .0000 0000 .0000 .0001 .0000 .0002 .0001 .0000 .0000 .0000 Nitrites. "I Oi .0963 .0814 .0525 .0600 .0097 .0090 .0052 .0150 i .0000 .0180 Nitrates. 1.57 1.10 2 20 [1.25 1.72 4.10 6.00 2.62 [3.67 2.22 2.70 2.00 2.00 2.20 Chlorine. rn 10.3 14 2 12.8 9.6 CO ci 00 b 4^ b |12.9 CO O p CO w b b Total. Residue on Evapora- tion. 2.6 1.2 4.6 4.6 2.3 3.2 0.6 3.1 Suspended. 4.6 4.3 5.2 5.2 3.6 6.7 6.8 7.2 6.2 6.0 Oi 4^ CO p b 4^ b to _ Loss on Ignition. 5.34 3.87 6.05 5.74 5.72 6.02 6.00 5.61 6.45 CO 8.50 11.80 7.20 5.20 Total Hardness. 4^ oo to 4.90 6.25 4.35 3.79 8.00 8.50 7.50 Alkalinity. 2,6'0 0.89 1.30 0.62 1.06 1.46 1.54 1.26 1.58 1.45 b, b- ic --4 H-^OO Sulphuric Acid. .144 .135 .150 .240 .050 .078 .006 .150 § Iron. 174 106 242 250 250 : : : : Bacteria Per Cubic Centimeter. RESULTS OF ANALYSES. 245 Pittsburgh City Tap. (Parts Per 100,000.) GO CD o o o 590 429 461 509 313 339 370 400 220 261 269 279 308 Serial Number. 1 Mar. 14 1898. Jan. 17 Dec. 20 Av'gs, kt n Nov. 1 " 8 " 22 Av'gs, Oct. 4 " 11 " 18 " 25 Av'gs, 1897. Sept. 9 " 22 " 22 " 27 " 30 Date of Collection. Slight Slight Slight V.slg't Slight V.sl'gt V. " V. " V. " V. sl'gt Slight I I ll ll Turbidity. bo 00 O to cn bo to to O O' o to .30 .30 .20 .20 CO b Mi tO tO b CnOOCnOT Color. 8 S' O .0096 .0074 .0101 .0060 .0120 .0124 .0154 .0140 0120 .0138 0220 co to .0136 .0142 .0126 .0116 .0138 Albuminoid Ammonia. 1 GO .0018 .0014 .0021 0040 .0016 .0006 .0019 .0008 .0018 .0020 .0030 .0014 b b b b b 28222 <cn 00 OO Mi o Free Ammonia. w o I B .0000 1 .0000 .0000 .0000 .0000 8888 o 8 8 8 .0000 .0000 .0000 .0000 .0000 .0000 Nitrites. M X £ 1.0450 o o -I Cn 0090' .0600 .0600 .0525 .0675 .0786 .0970 .1050 .0750 .0375 .0510 .0450 .0412 .0450 .0675 .0562 Nitrates. 1.34 1.12 £ 3.31 3.87 3 90 2.16 CO co 2.91 3.06 3.25 3.32 2.66 to co to to to cn ►-1 bo o o to co 4^ Chlorine. 10.6 b CH tO 18.7 17.6 24 4 14.0 16.1 15 8 16.0 16.4 16.4 15.0 Cr 4b oi 4b O GO 4^ to bo Total. Residue Evapof tion. p do CH to 0.2 0.2 0.1 0.2 Suspended. ! 4.0 CH to 6.0 bi 8.8 8.0 56 p cn o o cn o 4- bo o pt 6.4 6.4 4.4 5.2 6.0 Loss on Ignition. • % co in 4^ o 2.13 4.39 5.01 5 06 3.10 5.11 5.10 4.98 5.24 5.50 4- 4- on ^1 O' O' 0 0 01 WO Total Hardness. to » £ GO 07 4.05 K> Mi Mi b 4.79 pl Mi Mi Mi b b b co CO Cn CT Oi 4.94 4i Mi pi CT Mi b b b b b C O - 'I Alkalinity. io co 1.27 3.02 3.40 1.19 3.01 tO tO 4^ tO O tO CO GO HQQCn 2.02 1.10 1 85 1.78 2.92 2.47 Sulphuric Acid. .020 4,300 .130 14,000 CO to .051 17,633 .040 31,360 052 12,950 .062 8,350 .036 7,194 .056 812 .038 3,220 .015 3,848 .036 20,898 041 307 .030 .054 162 .030 162 034 .058 596 Iron. Bacteria Per Cubic Centimeter. 246 APPENDIX NO. 2. GATE CHAMBER. Samples from the "Gate Chamber" were collected, after the sand filters were placed in operation, twice a week until December, 1897, and, since then, once a week until the close of the experiments. Four additional samples were obtained for the special determination of "Suspended Matter." These samples were collected a short distance below the surface of the water in the "Gate Chamber," where the inlet pipe entered to sup- ply water to the Sand Filter Plant. Gate Chamber. (Parts Per 100,000.) 190 211 222 238 247 253 273 287 304 80 89 101 111 128 151 162 169 64 72 Serial Number. Av'gs,; 02 - - • - - - - CO tO t-O tC <-< J-1 OSWOOS^ffiMtO Av'gs, W ? 0 " 10 " 12 | " 18 " 24 " 26 " 30 Av'gs, 1897. July 26 " 29 Date of Collection. 0.05 o§oooo~oo ojq obb ojq'o o oop4cno74^W5-4^co 0.08 p ® p p p p o roe P o - o to p- to - Cl o o ci- 0.51 0.50 0.52 Turbidity. .32 ^tocotococok-cok- OOiOOiOOOOO 07; : : : ; ; o o Color. .0128 .0170 .0164 .0146 .0116 .0108 .0116 .0120 .0112 .0104 .0222 .0180 .0232 .0200 .0250 .0360 .0215 0180 .0158 1 .0260 .0250 .0270 Albuminoid Ammonia. Nitrogen as, .0017 .0025 .0011 .0016 .0022 .0017 .0018 .0012 .0016 .0014 .0015 .0004 <0007 .0018 .0028 .0018 .0025 .0006 .0016 osoo- .0023 .0018 Free Ammonia. 0000' .0000 .0000 .0000 .0000 .0000 .0000 .0000 .0000 .0000 .0000 88888888 oooooooo OOOOOOH-*^ .0001 .0000 .0002 Nitrites. .0471 .0600 .0300 .0450 .0300 .0375 .0375 ,.0605 .0638 .0600 .0763 1184 .0815 .0592 '.0740 .0375 .1125 .1050 .0225 .1481 .1850 .1112 Nitrates. 2.47 2.52 ,191 12.05 12.14 2.50 2.61 3 08 2.93 2.45 1.63 1.15 1.40 1.73 2.21 1.62 1.70 1.71 1.55 1.12 1 1.09 1.15 Chlorine. 13.3 11.6 10.0 12.0 13.2 12.8 14.0 14.8 15.6 16.0 14.1 9.7 13.0 10.8 24.8 26.0 7.2 11.0 10.4 15.0 12.4 17.7 Total. Residue on Evapora- tion. 4.3 . O t-1 8 CO . 4- . : io b b b: o : 6.0 2.6 9.5 Suspended. 5.0 Ci CX 4^ Ci Cn Ci 4^ bO O O GO O t\D O O bi 4.3 4^ 4X 4X p C3 to CO CO boaiBbih-^c:© co bo CO co bo o Loss on Ignition. Qi o' 5.60 5.49 5.64 5.95 7.18 6.93 6.50 3.60 4.90 pl 4- OiOiC: p pi Q Q coci4-CibocDbow Gi Oi 4- Q 4- Qi 4.39 CD 00 O GO Total Hardness. 4.95 4.45 4.88 5.05 5.58 5.53 5.59 5.52 3.74 4.20 5.13 4*. p CO 4- p p pp b bbbbb'^ b ©OCnOOCOOTO u-t 68T iT9 Alkalinity. 1.86 1.20 1.41 1.72 1.44 1.96 1.78 1.92 3.30 2.02 on 0 88 1.08 1.03 1.27 1.00 1.13 1.07 1.37 1.07 0.98 1.17 Sulphuric Acid. .044 .034 .026 .036 .016 .044 .030 .068 .060 .078 .177 .085 .120 .060 .420 .620 .010 .060 .040 s CH Iron. | 2,651 2^ J-1 00 h-1 H-lp1 4- to W> O<^7 - td Cl Cn Cn 4. O 4^CntOtOC<4^00O^l CO O Q< 07 O 07 CO O 07 1,280 725 750 575 2,075 1,150 1,325 2,362 2,275 lobo Oi o o o Bacteria Per Cubic Centimeter. RESULTS OF ANALYSES. 247 Gate Chamber. . (Parts Per 100,000.) Serial Number. 1 Date of Collection. Turbidity. Color. Nitrogen as, Chlorine. Residue on Evapora- tion. Total Hardness. Alkalinity. Sulphuric Acid. Iron. Bacteria Per Cubic Centimeter. Albuminoid Ammonia Free Ammonia. Nitrites. Nitrates. ■mox Suspended. T Loss on Ignition. 1897. 1 1 1 1 321 Oct. 5 0.05 .35 .0140.0014.0000.0750 2.98 16.0 7.2 4.80 4.32 2.58.052 1,876 333 " 6 0.04 .30 .0180.0018.0000.0938 2.80 16.8 6.0 5.48 5.20 2.16.072 18,550 347 " 11 0.03 .30 .0164.0014 0000.0825 318 17.2 7.2 5.4( 4.90 2.06.056 13,700 332 " 14 0.03 .30 0162 .0024.0000.0600 3.26 18.0 8.4 5.08 4.77 2 15 .046 27,300 374 " 18 V.sl'gt .20 .0111 .0024 0000.0900 3.59 16.0 6.0 5.58 5.09 2.51 .042 76,913 389 " 21 0.03 .20 .0120 .0012.0000.0375 3.84 16.8 6.8 5 16 4.97 2.51 .052 159,500 406 25 0.03 .25 0088 0020.0000.0375 3.81 18.0 7.2 1 5.06 4.89 2.85 .054 94,500 421 " 28 0.02 .20 .0168.0016.0000,0600 1 1 1 3.80 18.8 4.0 5.80 5.242.92 .040 206,500 Av'gs, 0.03 .26 0141 .0018.0000.0670 1 1 3.41 17.2 6.6 5.30 4.922.47 1 .052 1 74,855 433 Nov. 1 0.03 .25 .0090.0018.0000.0150 3 90 19.2 0.3 5.2 5.63 1 1 II 5.393.09 058 111,000 453 " 4 0.04 .20 .0118.0018 0000.0675 4.75 21.6 0.0 7.2 5.82 5.622.48.056 72,875 465 " 8 0.04 .20 .0132.0028 0000.0450; 4.36 22.8 0.4 8.4 4.98 4.713.85 .075 7,850 481 " 11 0.11 .30 .0170.0024.0000.0225 3.43 22.8 0.6 7.8 3.68 3.424.54 .078 501 " 18 0.88 .40 .0220.0014.0000.0825 1.80 32.8 17.2 7.2 3.41 2 61 1.37 320 17,950 520 c c no 0.08 .40 .0126.0008.0000.082512.03 12.8 0.5 4.8 2.90 2.31 1.11 .060 15 150 540 " 9<) 0.50 .30 70180.0010L0000.0750 1.63 16.8 l| 1 1 1 II II 6.0 6.0 2.64 2.07 0.89 .150 33,075 Av'gs, 0.24 .29 .0148 0017.0000.0557 1 818 21.3 3.6 6.7 4.15 2.48 114 42,983 557 Dec. 6 0.36 .30 i ! !| 0086.0010 0000! 1500 1.40 23.6 12.0 8.4 1.42 1.15 2 16 .190 28,850 573 " 13 0 09 .30 .0088.0022.000011200 1.90 15 6 0.2 6.4 2.25 2.02 1.27 .120 7,800 593 " 20 0.13 .30 .0078.0012 0000.0450 1.41 124 2.0 6.0 1.64 1.36 1.10 .132 609 " 28 0.06 .30 .0088.0014.0000.0900 III 2.21 11.8 0.0 3 4 2.04 1221.99 .060 1,900 Avg's, 0.16 .30 .0085.0014.0000.1012 1 1 1 1 1.73 15.8 3.5 6.1 1.84 1.441.63 .125 12,850 1898. | II i 625 Jan. 3 0.04 20.0042.0014.0000 0750 1.95 12.0 0.0 3.6 2.90 2.182.13.050 1,625 638 " 10. 0.30 30 0076.0012.0000.13501.64 18.8 6.8 6.81 2.20 1.911.58.072 16,175 664 " 17 0.26 30 0080.0010.0000.0900:1.21 15.2 5.2 4.4 1.86 1.511.44 192, 21,275 682 " 24 0.50 30 0098.0010.0000: 0525 0.94 18.811.2 7.2 1.68 1.120.68 200 26.150 698 " 31 0.08 20 0052 0016.0000.1050 il.12 7.4| 0.0 ,o| 1.90 1.301.03 076 2,350 Av'gs, 0.24 0070 0012j.0000|. 0915' 1.37 ll 1 L4.4 4.6 1 2.11 1 | 1.601.37| 118 13,515 APPENDIX NO. 2. 248 Gate Chamber. (Parts Per 100,000.) ===============^-^::=:=::==::=======:=T^--=====^====^=^========^^ ■ ] Residue on U § Nitrogen as, Evapora- I § ® B c • TI0N- g 'S a I s u g ' £ £ < 2 o 'S 5 S 4 J • 'S -o S 5 5 fl 5 a 5 I ? S ihM H D U •s £ £ li 1 i 1 5 o 1 ":al - 3 S » * U a a g g । 3 A | < < ■< re ° 1898: « I i 718 Feb. 7l 0.04 .20.0050.0014.0000.16501.6613.2 0.0 5.8 3.22 2.491.34.056 1,700 738 " 14 0.32 .30.0108.0018.0000.20251.3018.4 9.4 3.2 2.41 1.33,0.61.212 25,600 757 " 21' 0.16 .27.0210.0014.0000 ... 1.21 10.8 0.4 3.6 2.90 1.701.33.148, 12,025 775 " 28j 0.04 .20.0058.0012.0000.05251.00| 8.4 0.0 1.6! 2 66 1.921.32.050! 6,125 I I I I Av'gs, 0.14 .24 .0106.0014.0000.14Oo|1.29 12.7 2.4 3.5 2.80 1.801.15.116| 11,362 793 Mar. 7 0 04 .201.0048.0014.0000.0525 1.28 9.4 0.2 2.8 3.24 2.5111.55.040 5,100 813 " 14 0.11 .251.0068.0014;.0000.0375 1.61 8.3 0.3 2.8 2.80 1950.96.020 12,025 828 " 21 0.90 .22.0158.0016.0000.0525 1.28 29.618.4 4.0 1.90, 1.400.17.158 843 " 22; 1.00 .25 .0126.0088).0000.0600 0.86 54.040.9 9.2! 3.82 2.704.57.082 56,000 848 " 28 0.20 .25 .0110.0016.0000.0450p.89 9.5 0.4 4.0 2.66 1.001.06 018 4,750 Avg's, 0.45 .231.0102.0030.0000.0495||1.18 22.212.0 4.6 2.88 1.911.66.064|| 19,469 869 Apr. 4 0.08 .2o| .0060.0020.0000.O45o|1.14 9.2 0.0 3.6 2 62 1.541.03.027] 2,937 888 " 11 0.04 .25.0064.0012.0000.06751.24 8.2 0.0 2.2 2.88 2311.17.050 3.037 907 " 18 0.05 .22.0118.0018.0000.05251.50 8.8 0.4 3 6 2.54 2.101.50.055 2,525 925 " 25 0.20 .25 .0090.0036.0000.05251.30 9.8 0.2 4 8 2.98 2.510.85 028 16,000 Av'gs, 0.09 23 .0083.0021.0000.0544| 1.29 9.0 0.1 3.5 2.75 2.111.14.04o| 6,125 j I I | II I || 945May 2 0.03 .27|.0132.0018 0000.0225 1.36 8.2 0.2 2.8 2.64 2.240.34.028 3,120 969 " 9 0.28 .27.0120.0014.0000 02251.13 14.2 4.6 4.2 2.68 1.901.16|.120|| 19,400 992 " 16 0.20 .25.0122.0010.0000.0075'2.32'13.2 3.2 3 4 3.12 2.600.521.030 33,600 1022 " 23 0.15 .40 .0140.0006.0000.037510.95 12.4 5.4 3.2 2.82 1.900.79.016'1 13,900 1043 " 31 0-07 .27.0068.0006.0000.0600'1.21 7.0 00 3.6 2.68 2.300.89.018| 1,960 III I II I'll II I I 1 I Av'gs, 0.15 .29.0116.0011.0000.03001.3911.0 2.7 3.4 2.79 2.190.74.042s 14,400 li I L I I II I 1066,Tune 6 0.02 .20 .0068.0024 0000.0300,2.14 9 0 0.0 3.6 3 20 2.950.75.010; 3,460 1085 " 13 0.03 .39.0110.0028.0000.0300 2.48 11.9 0.5 4.8 3.60 3.401.54.004 21,200 1110 " 20 0.65 .30.0110.0012.0000.0225 1.54 36.826 8 4.8 3.30 3.240.92.025 25,100 1136 " 27 0.07 .20 .0070|.0024.0000.0750|2.48 13.6 3.4 4.1 3.26 3.001.30.012 3,770 Av'gs, 0.19 .25 .0089 .0022|.0000.0394 2.16 17.8 7.7 4.3' 3.34 3.151.13.013, 13,400 I I I I I I RESULTS OF ANALYSES. 249 Gate Chamber. (Parts Per 100,000.) 1360 W Q 1016 Gate Chamber. (Special.) (Parts Per 100,000.) 1255 1285 1315 1345 1377 1162 1187 1208 1237 Serial Number. Aug. 20 Av'gs, June 3 " 4 1898. May 18 Av'gs, Aug. 1 " 8 " 15 " 22 " 29 Av'gs, 1898. July 5 " 11 " 18 " 25 Date of Collection. 52'1 1 V.sl'gt Slight 1.08 p g 0.70 0.28 0.12 0.31 0.09 0.05 o o o c> o o o c Ci Ci ►£. Cl Turbidity. CO o 00 O bo bo o o bO CD •F 25 JO .30 .35 .27 .27 .30 .22 Color. .0061 .0060 .0062 H 1 .0130 '.0122 '.0110 .0100 .0072 .0098 .0130 .0094 1.0088 ,.0080 1 Albuminoid Ammonia. Nitrogen as, .0017 8100' 9100' .0025 .0032 .0024 .0022 .0024 0024 .0028 .0026 .0042 .0022 .0022 Free Ammonia. .0000 .0000 || .0000 .0000 .0000 .0000 .0000 .0000 .0000 .0000 .0000 .0000 .0000 Nitrites. 00S0' .0375 .0225 pew .0525 .0450 .0600 .0225 .0450 .0694 o o o o CR CD bO O O CH CH O O O Nitrates. o 2.03 06*1 esT --Jtctcw bs co to di co W LO O O CO bO to W W - Cl CO CO 0 4-043 Chlorine. 1 88.2 8.4 CO 00 CD O OSH 119.7 | H* H-1 t\3 CO H p LC p DOS WQO 12.7 9.4 11.2 14.7 15.6 Total. Residue on Evapora- tion. 6'ZZ 0.3 o o Cl o 104.4 p bO p CO p p bo cd co cd 6'0 1.0 1.2 1.3 0.0 Suspended. h 3.8 3.8 3.8 1 Is 8 bo CO CO 4- 4^ Ui Co 4i. Cn rfK 4.8 p bo bo o h-1 Loss on Ignition. bO O O 2.90 08*3 i00'8 S0J 5 73 3.98 3.70 2.80 3.92 4.56 cn co co Ui 4- Cn to Cn to Ci Total Hardness. 1.72 2.71 2.70 2.73 2.05 co s 4.54 3.56 2.82 1.96 2.92 3.47 2.90 3.48 4.10 3.40 Alkalinity. £ 0.85 bo • CH • 1.01 CO Ci O CO Ci 4* -; -.J 4- co 98'1 0 24 0.92 182 2.47 Sulphuric Acid. H .016 co £ .016 .028 .014 .020 .010 .010' o bO bO .024 .030 .026 '.008 Iron. 25,000 1 2,660 ww wb o 1.0 o o 17,000 19,200 27,500 49,400 4,800 12,600 1,700 8,450 6,850 3,850 14,400 8,750 Bacteria Per Cubic Centimeter. 250 APPENDIX NO. 2. SETTLING BASIN. Samples from the "Settling Basin'' were collected twice a week after the sand filters were placed in operation, until December 1, 1897. From that time until the close of the experiments samples were collected once a week. These samples were collected at the surface of the water in the central well, from which the water was supplied to the filter using settled water. / Settling Basin. (Parts Per 100,000.) <ooo-icn44cotoi-'co O< OO 4- 4- CO CO CO to H4 0 wtc c tccco -r O Cn WWW Serial Number. Av'gs, GO CD CO to to to 4-* 44 O -1 CD O O 4- CO -1 t o Av'gs, - - - - - - - c at? 00 to to t-4 O O 44 00 to CO Cn to Av'gs, 1897 July 18 " 26 " 29 Date of Collection. 0.04 <5 r. Pm poooKOp o o o o oopo o OOP 4- 4- CO 4- g CO 4- 0.10 0.09 0.07 0.03 V. t'd 0.30 Dec'd Slight 0.00 Slight 0.33 Dec'd Turbidity. .32 44tOCOCOCOCOCOCO44 OOOtOOOOOOt .45 L- OS- Color. b co 1 .0156 .0156 .0160 .0122 .0120 .0112 .0122 .0122 .0112 .0204 00000000 HHtONIOMtvH Cnoot04444t000i c. ai c coi 0 4-0 .0234 .0202 .0280 [.0220 Albuminoid Ammonia. Nitrogen as, • g CO 888888888 H M H H to H o; H tc OiQ^CitOO^CDCO .0015 88888888 H C H - io tc tc 0 .0031 .0046 .0035 .0013 Free Ammonia. .0000 iiliiiiti i iiiiwii I .0000 .0001 .0000 Nitrites. o _ 00 .0675 .0300 0488 .0150 .0300 .0150 .0638 .0450 .0525 .0675 .1260 .0741 ,0518 ,0518 .0375 .0937 .0450 .0600 .1075 .0075 .1853 .1297 Nitrates. p b co_ 2.30 '2.16 1.92 2.31 2.68 2.69 3.75 3.42 2.40 1.65 1.30 1.30 1.20 2.29 1.44 2.37 1.74 1.59 1 1 70 2.75 1.10 ,1.25 Chlorine. co b 10.4 10.8 11.6 14.0 12.6 15.6 16.0 17.2 17.2 11.4 1 pOWHOippp O O to O 44 co to co 14.0 13.2 15 3 13.5 Total. Residue on Evapora- tion. 1.3 . . p O H . : ' bo bo co b co : 5.5 03 pl ^7 b b b Suspended. 5.4 pppppp 4- 4- tC 000000444400044 4- bo 4.4 3.6 4.1 5.6 5.6 6.0 4.0 4.8 03 4^ pl ^7 to k) Loss on Ignition. 5.47 4.20 5.41 6.27 5.55 6.82 7.12 5.48 4.52 3.87 5.71 4.36 ; 4.92 j 5.53 7.06 j 7.40 1 6.42 1 5.57 4.40 co 4^ pi 4^ CH to S Total Hardness. 4.91 4.28 4.77 4.94 5.45 5.59 5.33 5 40 4.65 3.78 pi IC 44 w w 4.01 a 0 st tOCO00CccntOtO44 tOtOtOOCOOOCn 6 05 44 44 p O - I 04 44 O O Alkalinity. 1.84 1.47 1.44 1.58 1.37 2.02 1.61 1.68 2.99 2.44 0 00 00 1.03 1.10 1.38 1.20 1.14 0.96 0.87 1.16 Hl b to Sulphuric Acid. |0Z0' ISO FZ0' ow 9S0' OSO 910 sso ISO' .070 .060 .120 .200 .160 .030 .037 .030 .147 .040 .230 .170 Iron. 1,401 J5 2^ J0!-1 w "to 7-4 lo ~o to -i 7-4 co 0 O H -4 44 to to 0 O -I ONOtHQtOOWQi 1,137 ooloob • cnlob to co to to : ^7 0 Ql ^7 Qi Qt . C3 Qi O | 2,275 1,450 3,100 Bacteria Per Cubic Centimeter. RESULTS OF ANALYSES. 251 Settling Basin. (Parts Per 100,000.) Ci Cj Ci Ci cd Ci co to CD Cn CD Ci 558 574 594 610 Cjt © © 4- 4x 44 4- 44 to © CO Cl © 00 H H tO W CS 4^ *■ 322 334 348 363 375 392 407 422 Serial Number. Av'gs, 1898. J Rll. O " 10 " 17 " 31 Av'gs, o o - tO tO H CO O CO Ci Av'gs, Nov. 1 " 4 " 8 " 11 " 18 " 23 " 29 Av'gs, CD to to to CO Cn co 4-^ -^ Ci cn Date of Collection. 0.13 0.04 0.21 0.22 0.07 oro poop 8 5 8 o 0.18 © © o o o o © k. U b> b b b b 44 © © 00 © 44 CO 0.03 c O O © ^ © © © o ©©©-t©©©© to to COjq CO CO CO 4- Turbidity. to Ob 0g- 0g' r to CO 00 io CO O © cn © .26 to 4- bo to i-1 to to ©©©©©©© .24 .30 .30 .25 .30 20 .20 .20 .20 Color. 8 8888 W ' 1 it- 44 co cc ci .0089 .0106 .0092 .0080 .0080 .0147 .0098 .0110 .0120 .0164 .0216 .0140 0184 0133 .0148 .0158 .0142 .0158 .0106 .0116 1.0090 .0146 Albuminoid Ammonia. Nitrogen as, .0014 8888 IO 4- Cl Cl .0014 8888 *- to co o o o 1500' 8888888 h- H H IC Ci CO tO 4^ to 4^ CO .0017 88888888 IC r-* CitO4^GOCiCi4-'C® Free Ammonia. 0000 .0000 0900 .OOOOf.1425 .0000.0900 .0000.1050 1 1 © 8 8 © Cl .0000.1350 .0000.0525 .0000.0525 .0000.0825 .0000.0600 Miiir .0000 bbbbbbbb Nitrites. .1009 ... ,0750 .0450 .0300 .0750 .0750 .0600 '.0703 1 .1050 ,.1050 .0750 .0600 .0825 .0375 .0450 .0525 Nitrates. 147 1.99 1.70! 1.18 1.01 1.84 2.28 1.72 1.48 1.87 co CH 00 3.64 5.12 4.29 5.15 2.62 2.07 2.15 95'g 2.69 2.76 2.81 2.98 3.61 3.92 3.81 3.52 Chlorine. 12.0 12.0 15.6 13.2 7 2 co 13.2 12.0 12.0 10.4 20.4 18.8 21 6 21.6 23.6 26.8 14.0 16.4 17.0 16.8 16.8 168 17.2 16.0 15.6 16.8 20.0 Total. Residue on Evapora- tion. 1.7 p co co o b io bo b 0.4 0'0 8'0 8'0 55 44 H 50 O O O O b io io s b b b Suspended. CO bo tO 4^ 44 44 ©A oo<© CO 44 4- 01 ci © A x 1 6.4 7.2 9.2 10.0 9.2 5.0 6.8 Ci bo CO p Ci Ci Ci J Ci Ci bo o o co 4^ 'to bo Loss on Ignition. to H-1 bO to OO co 44 © 44 to to CO 2.31 2.06 2.54 2.17 2.46 4.42 to to CO Cn 4- pi © CO © io © *-I CO A X *. O 0'X X O 5.13 co U k> b h w b o ODCitOtOCi^OCO Total Hardness. 1.67 1.82 1.96 1.60 1.29 bo CD 1.721.23 2 331 27 1.861.06 1.641.47 1 4.022.16 1 5.23 5.65 4.56 4.89 3.09 2.53 2.20 4* 8 4.12 5.29 4.80 ' 4.78 1 4.98 5.03 1 5.02 4.84 Alkalinity. 1.51 O H H tO co io - i Ci CO CO Ci 1.26 1 to co to to P W M co b< ' CD Ci O OI cn - • 2.36 to to to to to to to to CR -1 to 4^ O O Ci O( o OI CD Ci 4^ Sulphuric Acid. .126 5 5 S 8 10 0 4-0 .102 f90' 911 sir oir _I CD .042 .054 .052 .088 .360 .110 .130 I 8f0 bbbbbbob 4 - 4 CC X C. -I X 4wtooxoa>ic Iron. 14,256 2,425 16,525 32,875 5,200 12,950 16,925 11,325 18,500 5,050 44,733 103,250 i 76,525 17,425 24,400 24,350 22,450 39,003 04'11,^4 J0iCnp>j-'j0stostOxt0 b'bo'cn'b'b'bibj'io tO^JOtOGOCCO C'l Cl C C IC O s Bacteria Per Cubic Centimeter. APPENDIX NO. 2. 252 Settling Basin. (Parts Per 100,000.) Serial Number. j Date of Collection. Turbidity. Color. Nitrogen as. Chlorine. Residue on Evapora- tion. Total Hardness. Alkalinity. Sulphuric Acid. Iron. Bacteria Per Cubic Centimeter. Albuminoid Ammonia. Free Ammonia Nitrites. Nitrates. Total. Suspended. Loss on Ignition. 1898. 719 Feb. 7 0.03 .15 0054 .0016 .0000 .16501.6015.6 0.0 7.6 3.28 2.25 1.47 .054 1,775 739 " 14 0.19 .30 .0112 .0018.0000.22501.40 10.6 1.0 2.4l 2.54 1.560.49 .136 33,600 758 " 21 0.10 .30 .0180 .0018.0000 1.18 10.2 0.2 3.0| 3.01 1.721.25 .098 11,375 776 " 28 0.06 ■22 .0058 .0016 .0000 .0600 1.34 8.2 0.0 2.0 2.94 2.10 1.34 .065 13,825 Av'gs, 0.09 .24 .0101 .0017 .0000 .1500 1.38|11.1 0.3 3.7 2.94 1.91 1.14.088 15,144 794 Mar. 7 0.05 .25 .0048 .0014 .0000 .0525 II 1.48 10.2 0.2 3.4 3.04 2.34 1.34.035 7,350 814 " 14 0.06 .22 .0056 .0010 .0000.0375 1.64 10.2 0.2 3.2 3.06 2.20 1.20 .035 13,000 829 " 21 0.17 .17 .0138 .0016 .0000 0600 0.98 11.9 1.1 2.8 2.84 2 000.30 .060 849 " 28 0.16 .25 .0100 .0016 .0000 .0300 0.85 9.5 0.3 4.4 2.32 0.951.16 .022 7,316 Av'gs, 0.11 .22 .0085 .0014 .0000 .0450 1.24 10.4 0.4 3.4 2.81 1.871.00 .038 9,222 870 Apr. 4 0.11 .20 .0064 .0020 .0000 .0450 1.07 9.6 0.0 4.0 2.60 1.5o'o.86 .038 4,875 889 " 11 0.06 .20 .0070 .0018 .0000 .0525 1.30 7.2 0.0 2.2 2.60 2.101.31 .050 2,550 908 " 18 0.04 .20 .0120 .0028 .0000.0300 1.82 1 9.8 0.2 3.0 2.66 2.221.65 .052 2,300 926 " 25 0.06 .22 .0084 .0038 .0000.0450 1.62 9.8 0.2 3.2 2.90 2.47 1.20 .040 7,150 Av'gs, 0.07 .20 .0084 .0026 .0000.0431 1.45 9.1 0.1 3.1 2.69 2.07 1.25 .045 4,219 946 May 2 0.04 .25 .0104 .0014 .0000.0225 1.28 8.4 0.0 3.2 2.30 2.05 0.34 .032 3,100 970 " 9 0.14 .25 .0080 .0012 .0000.0300 1.28 12.0 3.2 4.0 3.12 2.141.07 .095 5,550 993 " 16 0.06 .22 .0060 .0012 .0000.0075 1.68 9.0 0.4 3.8 2.60 2.311.00 .018 6,450 1027 " 23 0.15 .30 .0138 0012 .0000.03001.00 10.2 2.6 3.3 2 30 2.100.68.028 6,400 1053 " 31 0.05 .35 .0060 .0008 .0000 .0375 1.26 P 0.0 3.3 2.60 2.320.85 .025 1,800 Av'gs, 0.09 .27 .0088 .0012 .0000 .0255 1.30 9.3 1.2 3.5 2.58 | 2.180.79 .040 4,660 1067 June 6 0.03 .20 .0070 .0016 .0000 .0225 2.10 9.0 0.0 3.8 3.08 2.650.71.016 3.261.16.002 2,250 1086 " 13 0.03 .27 .0098 0024 .0000' 0225 2.30 .0000.0225 1.70 W.6 17.2 00 7.2 4.2 3.40 5,500 1115 " 20 0.27 .30 .0098 .0020 3.8 3.52 3.001.13.022 12,600 1137 " 27 0.07 .17 .0068 .0022 .0000 .0525 2.3812.0 2.0 4.2 3.08 2.920.82.016 1 1 2,500 Avg's, 0.10 .23 .0083 .0020 .0000 .0300 2.12112.2 2.3 4.0 3.27 2.960.95|.014 5,700 RESULTS OF ANALYSES. 253 Settling Basin. (Parts Per 100,000.) 1256 1286 1316 1346 1378 1163 1188 1209 1238 Serial Number. Av'gs, Aug. 1 " 8 " 15 " 22 " 29 Av'gs, 1898. July 5 " 11 " 18 " 25 Date of Collection. 0.24 0.50 0.22 0.16 0.22 0.08 0.07 0 06 0.03 0.15 0.06 Turbidity. io CO 1 S3' OP 30 .20 27 .20 Co'or. .0104 .0110 .0128 .0098 .0104 .0078 O' '0120 .0096 .0080 '.0086 Albuminoid Ammonia. Nitrogen as .0024 .0030 .0026 0016 .0024 .0021 9200' .0020 .0042 .0022 .0022 Free Ammonia. 1 0000' .0000 .0000 .0000 .0000 .0000 .0000 1 Hit Nitrites. o .0600 .0525 .0675 .0225 .0450' 2890' .0825 1.0675 .0600 .0450 Nitrates. 4.35 2.64 2.22 1.40 1.62 2.67 1.50 2.34 4.20 2.63 Chlorine. 2'91 1 - ~ 44 O do to Ci do 14.6 8.6 13 2 20.3 16.4 Total. Rej Ft Ox h W to w cn m bo © 2.2 O'HWO 0^4-4^ Suspended. z o S 4.2 5.6 4.4 4.6 3.4 3.0 4.9 CR C3 4*- 4>- '*• a a b Loss on Ignition. > © ' a 3.97 5.94 3.90 3 50 2.88 3.62 4.61 3.00 3.60 6.15 5.68 Total Hardness. 3.08 JO H-1 to 00 4* do bo bt to o co to o 3.30 2.88 3.41 3.90 3.00 Alkalinity. 1.02 1.47 1.27 1.03 100 0.32 1.55 W H o o CO CO O' O co GO OX Sulphuric Acid. .015 o o o o o _ t to o o a to to .021 bbbb o to co to Cl to C: O Iron. 10,200 28,700 11,100 4,150 5,450 1,600 8,250 'bi'^'o'co 888S Bacteria Per Cubic Centimeter. EFFLUENTS -SAND FILTERS. Samples of the "Effluents" from the "Sand Filters" were collected twice a week until December i, 1898, and once a week from that time, until the close of the experiments. These samples were collected from quarter-inch petcocks tapped into the effluent pipes from the sand filters. Sand Filter No. 1. (Parts Per 100,000.) 56 65 74 Serial Number, Av'ga, 1897. July 18 " 26 " 29 Date of Collection. Slight Turbidity. Color. 1 r18' .0175 .0240 .0136 Albuminoid Ammonia. Nitrogen as, .0051 .0139 .0013 .0000 Free Ammonia. .0001 .0002 .0000 0001 1 Nitrites. to 03 .0465 .1780 1483 Nitrates. 1 607 on 91 1 187 Chlorine. 28 9 64.1 11.9 10.6 Total. Residue on Evatora- tion to 3.0 0.3 0.2 Suspended. CD 00 21.4 4.2 3.7 Loss on Ignition. bi CD 7.08 6.25 6.45 Total Hardness. 9.12 oopoo to co to HOC Alkalinity. bO OS 1.06 1.69 1.03 Sulphuric Acid. to .140 .150 .090 Iron. 625 750 500 Bacteria Per Cubic Centimeter. APPENDIX NO. 2. 254 Sand Filter No. 1. (Parts Per 100,000.) 323 335 349 364 376 393 408 423 192 213 224 240 249 255 275 289 306 82 91 99 113 130 153 164 171 Serial Number. Av'gs, Oct. 5 " 6 " . 11 " 14 " 18 " 21 " 25 " 28 Av'gs, Sept. 2 " 7 " 9 " 14 " 16 " 20 " 23 " 27 " 30 Av'gs, 1897. Aug. 2 " 5 " 9 " 12 " 18 " 24 " 26 Pate of Collection. Clear ic d O; Q g : g k' gb Turbidity. 8_ 88888888 .06 .0076 .20 .10 .20 .05 .00 .00 .00 .00 .00 co CH .40 .30 Color. .0078 28888888 tO 4^ Ci Ci GO CZ 3 CO O Ci to 4^ 4- Ci O CO .0088 0072 .0084 .0084 !.0080 .0064 .0068 .0068 .0076 .0100 .0100 .0080 .0086 .0106 .0115 .0115 1.0106 .0096 Albuminoid Ammonia. Nitrogen as, .0017 88888888 GO O Ci 4- GO Ci Ci GO .0014 .0016 .0012 .0012 .0010 .0026 0008 .0010 .0020 0016 6000 .0001 .0001 .0014 .0014 .0009 .0017 .0005 .0014 Free Ammonia. oooo- liiiiOi 0000' .0000 .0000 .0000 .0000 0000 .0000 0000 .0000 '0000 .0001 Nitrites. o GO o__ .1200 .1500 .0900 .0675 .0900 .0450 .0450 .0450 .0548 ■ .0600 .0450 .0525 .0450 .0358 0300 .1125 0562 .0562 1 1.0707 1 OOOOOOoLj 4- Ci © cc ai M 7. tc ai woe a J- et c. OOTOOwOcCO Nitrates. co to 2.75 2.60 2.80 3.12 3.45 3.21 3.56 3.48 2.43 2.00 1.92 2.11 2.15 2.36 2.50 3.11 3.26 2.47 151 1 1.20 1.23 1.28 2.01 1.46 1.15 1.91 1.82 Chlorine. FZI 02 o o 'o c» to 4- bo 13.8 10.2 12.0 12.4 14.0 13 8 14.8 14.6 17.2 15.6 CO OpOCOHOtO Ci 4^ tO 00 to tO o O Total. ; Residue on Evapora- tion. :::::::: :::::::: Suspended. ^7 ~i 02005 cn cn 02 0_CT>_CO bo 4- C2 02 pl to 4.0 4.4 4.4 5.2 5.2 5.6 5.6 6.8 6.0 co co 4^ 4- tO CH CO W OS 4- ocoto^^bsco Loss on Ignition. 5.99 Ci pi pi Ci pi pi Ci CH m bo *-q b bo m m co CO 0 0 0 0-40 6.52 7.40 6.05 6.60 6.69 7.34 7.65 5.92 5.76 5.28 7.30 piCiCiGOCDQOCiCi bi n-* bi do C WCiCiOO h-Ch Total Hardness. 5.60 pi CH p1 pi pl cn Ci CH bcbbccio^b ^^OlCCOQtC 6.07 5.76 5.81 5.93 6.38 7.03 6.29 6.35 5.90 5.15 Ci 9.85 8.81 8.92 8.77 5 51 4.99 5.14 5.29 Alkalinity. 2.52 2.68 2.09 2.12 2.41 2.71 2.58 2.81 2.75 CD 1 58 1.30 1.54 1.58 2.06 1.85 1.85 2.78 2.64 1.07 1.07 1.08 1.19 1.20 1.17 0.86 0.68 1.30 Sulphuric Acid. 900' 88888888 ^5wtoHd5oa> 8 288888-82 W - Ji O yj 4- .034 .045 .045 .080 .012 .040 .014 .024 010 Iron. CO to 15 15 84 26 25 17 22 51 Ci 4^ tO to to CO 44. • HCtO 4-^014-: Bacteria Per Cubic Centimeter. RESULTS OF ANALYSES, 255 Sand Filter No. 1. (Parts Per 100,000.) 795 815 830 850 720 740 759 777 627 640 666 683 700 Ci Ci O' Cn h- Cn O' CD 435 455 467 483 503 522 542 Serial Number. Av'gs, Mar. 7 " 14 " 21 " 28 Av'gs, Feb. 8 1 " 14 " 21 " 28 Av'gs, | 1898. Jan. 3 " 10 1 " 17 " 24 " 31 Av'gs, Dec. 6 " 13 " 20 " 28 Av'gs, 1897. Nov. 1 " 4 " 8 " 11 " 18 " 23 " 29 Date of Collection. b .001 .006 .010 .004 .014 Clear .023 .010 .010 .043 Clear .074 .045 .011 Clear V.sl'gt V. " ^^22 Q p g Turbidity. .(M> ! 8888 o .00 22 .20 .00 .02 .00 .00 .10 .27 .22 .00 .00 .10 k w -* c c c b O' O D' O O O O Color. .0040.0016 1 .0032.0022 .0036L0012 .0060 0012 0034.0020 8100' UQQ' 1 .0036 0052 .0182 .0040 6J00' 1 .0044 .0038 .0062 .0060 .0040 .0056 .0074 .0048 .0060 .0044 .0082 .0076 .0068 .0110 .0140 .0086 .0120 Albuminoid Ammonia. Nitrogen as. .0012 .0016 .0014 .0012 1100- 0012 .0010 .0010 .0010 .0014 .0015 8100 0100' 8100 9100' .0014 8 8 o 8 8 8 8 00 IC to c: to C Free Ammonia .0000 05251.23 9.5 1 |i .9Z80 0000' SWOOOO' 0CW0000' 0090*,0000' II .0000 nil .0000 1 8 8 8 s 8 88888 .0000 .0000 .0000 0000 .0000 1 .0000 Mom Nitrites. O' .1800 .2400 .0675 0501' 0060' |QZ90' 0061" 0991' 9Z90' .0937 .1425 1050 .0600 .0675 IZZO' 1 .0300 .0750 .0825 .0600 .0750 .1500 .0675 Nitrates. 1.39 1.48 1.05 102 1.44 1.72 1.62 1.14 1.30 CO CD 2.00 1.74 1.16 0.86 1.21 1.90 2.32 1.81 1.67 1.81 3.50 5.08 4.66 5.41 2 82 1 95 1.90 Chlorine. 10.4 8.0 10.0 9.6 10.9 14.8 9.6 10.0 9.2 1 9.9 12.8 108 '10.4 8.0 11.7 12.4 12.4 10.0 12.0 s b' 20.4 23.0 22.4 22.4 16.8 11.2 13 2 Total. Residue on Evapora- tion. 0.0 o o o o b b b b 0.0 o o o o b b b b 0.0 0.0 0.0 0.0 0.0 0.0 p 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Suspended. 3.9 £. CO W tk b b b CO 6.0 2.8 3.4 2.8 u r tC 4- CO JO 4^ to go to 4- co 4.3 1 44 5.6 4.0 3.2 co 8.4 9.0 9.0 8.8 7.6 3.2 5.2 Loss on Ignition. 3.59 • 3.88 4.32 2.99 3.19 3.23 3.84 2.64 3.28 3 16 3.13 3.24 4.64 2.52 2.84 2.43 3.26 ll 3.28 3.18 2.88 3.70 1 5.01 6.39 6.38 5.80 5.72 4.13 3.48 3.20 Total Hardness. 1 2.741.05 3.00 3.32 2.55 2.09 2.68 3.09 2.82 2.34 2.48 to o co 2.85 4.08 2.05 2.18 2.01 to bo 2.80 2.83 2.41 3.19 4.74 6.15 6.14 5.53 5.41 3.82 3.19 2.92 Alkalinity. 80'1 ,08'0 J8I 96'1 1.22 1.65 0.86 1.13 1.26 1.52 2.13 1.85 1.44 1.10 1.10 co Ci 1.44 1.27 1.13 1.61 2.23 2.85 2.51 3.78 2.42 182 1.10 1.13 Sulphuric Acid. .016 .024 .015 .010 .014 .028 .020 .046 .015 .030 850' .024 .014 .042 .046 .016 I£0* .036 .034 .030 .026 ^024 .003 .004 .004 .004 .066 .042 .044 Iron. 38 39 94 271 119 710 133 122 309 H-1 to Or CO to CH CD GO O t O - I O Cj < 10 10C 126 81 93 988 45 26 26 1,701 383 137 Bacteria Per Cubic Centimeter. 256 APPENDIX NO. 2. Sand Filter No. 1. (Parts Per 100,000.) co co co to to ►- GO CH CD -I ^7 - 7 1164 1189 1210 1239 1068 1087 1111 1138 947 971 994 1023 1044 CD CD CO GO IO O CD ^7 -IOC- Serial Number. R rn i> c cp to to >-> _ cd to cn go Av'gs, 1898. July 5 " 11 " 18 " 25 Av'gs, June 6 " 13 " 20 " 27 Av'gs, May 2 " 9 " 16 " 23 " 31 Av'gs, ! 1898. Apr. 4 " 11 " 18 " 25 Date of Collection. .007 .000 .000 .007 .017 .010 .001 O D O O g to g .010 .012 .005 .015 .008 .011 o o o o o tO O O O COClCtCH JOO' .010 .001 Clear .001 Turbidity. to .05 .10 .10 .32 .05 .09 5§So .06 .05 .00 .10 .10 o ' CD h w b b h woo wo .02 b b b o o o o Color. 0S00' .0040 .0040 .0048 .0064 .0058 s Cn .0100 .0040 .0048 .0034 .0057 .0068 .0068 .0044 .0048 .0048 0052 .0062 .0052 .0038 .0038 .0050 0048 .0062 .0038 0052 Albuminoid Ammonia. Nitrogen as, .0022 .0022 .0020 .0008 .0020 .0040 .0023 O O o O o o o o to to to to CD O CC 4k .0016 .0018 .0018 .0008 .0022 .0010 .0018 .0012 .0010 .0006 .0006 .0021 8888 CO to -1 00 GO O O Free Ammonia. | .0000 .0000 .0000 .0000 .0000 0000' .0000 .0000 .0000 .0000 .0000 .0000 .0000 .0000 .0000 i b b b b b §§§§§ 8 8 Illi Nitrites. .0465 2.56 ll .0525 4.60 .0375 2.76 .0600 2.45 .0300 1.30 .0525 1.68 .0731 2.60 1 .0825 .0975 .0600 .0525 .0412 2.14 0225 0300 .0300 .0825 .0270 .0300 .0150 .0150 .0375 .0375 .0469 .0525 .0600 .0300 .0450 Nitrates. 158 2.30 3.84 2.68 2.20 2.45 1.70 2.20 1.31 tcbi-b w oo os o to 1.56 1.18 1.21 2.10 1.76 Chlorine. 12.5 16.9 16 0 11.7 9.2 8.6 14.2 98 11.2 17.0 18.8 11.2 to £ p CD O Oi Ci co 83 00 00 CD CO M bi^b^b 8.7 8.8 7.6 9.2 9.2 Total. Residue on Evapora- tion. 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 o o o o o O O O b O 0.0 0.0 0.0 0.0 0.0 Suspended. 4.1 4.8 4.4 4.5 3.8 3.2 5.2 4.4 4.0 6.4 6.2 4.2 3.9 3.8 4-2 4.9 3.1 CO CO tO to co GO 4^ Ci Cn to 3.1 3.2 2.4 3.6 3.2 Loss on Ignition. 5.36 7.60 5.22 4.94 4.68 4.38 5.97 4.42 4.76 7.48 7.23 4.42 4^ jx rfx M M O O Ci O Co Co 4.12 co 4k OS 4k OS CD H-> CD CD do OOOWO 3.46 3.18 2.98 3.80 3.90 Total Hardness. CO CO 4^ 4^ CH COOQ to CO 4^ co to 4.67 OS C3 4k 4k COMM 05 o o to <3i 4.10 4k OS 4k 4k f-J CO 4k O COCO 3.30 co co co co co 00 CO 4^ tO OCDCiOM 2.88 co co to to *4^ h-i bn 4- Alkalinity. - to 1.27 1.85 0.85 1.13 0.49 o o 0.34 092 1.95 3.44 1.01 0.82 1.27 1.03 0.92 0.86 0.58 1.13 0.75 0.79 1.03 1.14 b i-1 ° 4-< os to co O CO OS <31 Sulphuric Acid. w II .006 .002 .004 .002 .004 200' .008 .004 .006 .002 g o o o o o o o c 4 01-4- .012 .008 .008 .018 .013 .011 .010 008 .016 .008 .010 Iron. CH cd 52 85 40 67 52 107 45 49 290 43 GO Ci kJ 4k - J CD CO © Cn N O CD 4* 00 4^ <31 OS SO44SO tsO co to co to co c O oi H Bacteria Per Cubic Centimeter. RESULTS OE ANALYSES. 257 Sand Filter No. 2. (Parts Per 100,000,) 1 Av'gs, 324 336 350 365 377 394 409 424 193 214 225 241 250 256 276 290 307 83 92 100 114 131 154 165 172 •q Oi os Ox OxCC^I Serial Number. Oct. 5 " 6 " 11 " 14 " 18 " 21 " 25 " 28 Av'gs, Sept. 2 " 7 " 9 " 14( " 16 " 20| " 23 " 27 " n Av'gs, "ere co to to >-1 4-1 C O 4- CO I O CO cn to Av'gs, 1897. July 18 " 23 " 26 " 29 Date of Collection. Clear CC cc g 2 k :::::: < < < Q < < XL - EL ~ 2 V.sl'gt Slight V.sl'gt Turbidity. .00 .00 .00 .00 .00 .00 .00 .00 .00 o .20 .10 .20 .05 .00 .00 .00 .00 .00 .35 .40 .30 Color. 03 to .0080 .0108 .0076 .0092 .0068 0064 .0044 .0124 .0078 .0075 .0076 0092 .0078 .0064 .0076 .0076 0074 .0090 .0101 '.0110 .0085 .0080 .0095 .0136 .0098 .0114 .0092 .0158 .0233 .0122 .0160 .0116 Albuminoid Ammonia, Nitrogen as, § .0012 .0016 .0012 .0030 .0014 0014 .0008 .0018 .0015 .0014 .0014 .0006 .0008 .0032 .0010 .0014 .0022 .0014 .0009 .0001 .0001 .0010 .0012 .0010 .0016 .0005 .0014 eeoo' .0209 .0018 .0009 .0001 Free Ammonia. § oooooooo oooooooo oooooooo oooooooo .0000 ooooooooo ooooooooo ooooooooo ooooooooo .0000 oooooooo oooooooo oooooooo |.0001 0001 .0005 .0000 .0000 Nitrites. IC to .1050 .0825 .0825 .0675 .0975 .0450 .0525 .0450 .0533 ooPoooooo O O< o CO 4^ CO Cn CO O O O -C' O O' O O -U O o woocoucio .0760 .1260 .0750 .0888 .0592 .0300 .0937 .0750 .0600 Ox 00 HWOO 4- to -U »to oo ot CC o o o Nitrates. w CO CO CO CO CO to bp bx (X IO CH O -O 03 O to CC to CH o cn ex 2 40 1.93 1.98 1.97 2.11 2.33 2.64 3.05 3.37 2.20 bx GO 1.12 1.27 1.22 2.44 1.31 1.78 1.79 1.73 1.90 2.56 2.60 1.15 1.30 Chlorine. 17.9 15.2 16.8 17.6 18.0 17.2 18.8 21.2 18.2 13.8 bbk*bi»b^k 10.5 Opoppoot* o 4- bo to to to i-» bO co CO 47.4 23 5 13.8 11.1 Total. Residue on Evapora- tion. 4.4 7.9 L9 0.3 Suspended. 6.8 52 6.0 5.6 7.6 6.8 6.8 8.8 7.6 5.2 4.4 4.4 4.8 5.0 5.6 5.6 5.2 6.4 5.8 L 6 V 4^4^b3ppCOCOCO b * a> to t © c © 4'9 co co pt co ^t bo 4- >-> Loss on Ignition. 6.12 6.21 7.06 6.13 5.92 5.60 5.98 6.04 6.02 6.63 7.25 6 49 6.94 7.69 7.20 7.15 6.52 4.87 5.58 7.35 5.80 8.05 9.30 7.91 8.67 7.14 6.38 5.56 * 7.25 3.75 1120 7.37 6.68 Total Hardness. CH CnpppCnpOCn O 4 i- in Ci b W oooaocnwoco ex 5.68 6.09 5.22 7.10 6.99 6.49 6 61 4.95 5.50 to o 8.50 9.04 9.11 8.81 6.04 5.08 5.41 5.60 to Ox 40.50 29.70 9.75 8.64 Alkalinity. to Ox Ox to IO to to to to to to --i c; 't to 4* bi 4^ 00 CO 00 O C0 O CO to 1.47 1.20 1.70 1.72 1.96 1.85 2.13 3.80 2.27 1.17 1.17 1.24 1.37 1.24 0.79 1.03 1.37 1.99 H H W H h-1 CO (X GO cn to CO IO Sulphuric Acid. Ox .010 .016 .004 .001 .002 .002 .004 .004 .004 .008 .007 .004 .005 .001 .001 .001 .001 .010 .036 .075 .045 .080 .014 .030 .014 .022 '.008 .130 .100 .250 .085 .085 Iron. 00 19 10 12 16 18 22 25 26 03 >-' >-' to 4- o mh co -u 4- co -u CO ex 66 50 34 22 36 18 17 | 3,507 8,820 1,450 250 Bacteria Per Cubic Centimeter. APPENDIX NO. 2. 258 Sand Filter No. 2. 796 816 831 721 741 760 778 628 641 667 684 701 560 576 596 612 436 456 468 484 504 523 543 Serial Number. 1 ' Av'gs, tg „ 41 ,, £ 'JBK Avg's, Feb. 7 " 14 " 21 " 28 Av'gs, 1898. Jan. 3 " 10 " 17 " 24 " 31 Av'gs, Dec. 6 " 13 " 20 " 29 Av'gs, 1897 Nov. 1 " 4 " 8 " 11 " 18 " 23 " 29 Date of Collection. .014 .006 .015 .022 .013 Clear .015 .015 .010 .024 Clear .015 .045 .011 Clear V.sl'gt Clear Q „ 2Lcrq' - 7 r 'F aq g. Turbidity. s § 8 o o co .00 .17 .17 .00 [j .00 .00 .10 .25 .22 o .00 .05 .10 .00 1 60' .00 00 .00 .00 .10 .30 .25 Color. .0039 i1 0028 0032 .0058 .0073 .0034 0062 .0158 0038 .0046 .0048 0032 0058 .0046 .0044 | .0064 .0086 .0076 .0054 .0040 ..0091 .0040 .0080 .0070 .0106 0152 .0080 .0108 Albuminoid Ammonia. - 838 to to o to o 4100' 5100' 9100' 8100' 5100 8 1-i to .0014 .0012 .0012 .0008 0014 .0012 .0014 .0012 .0012 .0010 .0015 .0016 .0016 .0024 .0016 .0014 .0004 .0016 Free Ammonia. X o CD g .0000 0000 loooo 1 0000 0000' 0001 )• 0000' .0000 .0000 .0000 .0000 .0000 0000 .0000 .0000 .0000 .0000 .0000 .0000 iliiill Nitrites. § ► 00 o< 1 .0600 .0450 .0600 1 1.1000 1 .1725 10060 ' 0675 osor 1 .0750 '1575 .1125 .0600 ,1200 .0731 .0450 .1200 .0600 .0675 .0761 .0375 0675 .0675 .0525 .0825 .1425 .0825 Nitrates. ^'1 sri sri "n 1.41 II 1.66 1.47 1 19 1.33 II ■ 1.42 1 1.92 1.96 1.18 0.88 1.18 1.89 2.61 1.76 1.40 1.78 o.3o 3.66 4.73 4.14 4.78 1.79 1.97 2.50 Chlorine. 10.4 8.2 1 9.6 H-* O 14.8 10.2 10.0 9.2 p 14.8 124 10.2 8.0 8.0 9'11 12.0 12.0 10.4 11.6 118.4 1 20.8 23.2 22 6 21.6 14.8 12.4 13.6 Total. Res Ev o.c o o o p b b b o b 0.0 0.0 00 00 0.0 p 0.0 00 0.0 0.0 b p p p p p p p Suspended. 5 ► e o S ° co 4.0 । 3.8 i, 3.6 b co co co p 4.0 6.0 2.8 3.4 4.7 3.2 1 bn 5.2 6.0 3.2 3.6 dp 88 9.2 8.0 9.6 6.4 4.S 4.8 Loss on Ignition. 21 co 4.00 4.28 3.ie co bn co co co co to to oo b - GO 07) 3.47 5.22 3.98 2.80 2.61 2.74 3 41 3 34 2.94 3.14 5.68 6.70 7.36 '5 60 6.16 4.03 3.67 6.21 Total Hardness. co l 3.20 , 3.2( i 2.80 2.77 - 2.82 3.1( 2 38 2.80 to co 415 3 37 2.30 2.09 2.30 9Z'S 2.84 2.98 2.44 2.79 i SS9 6.55 7.03 5.3? 5.91 3.18 3.43 5.89 Alkalinity. £ 4.62 11.2? 0.27 to to 1.61 0.86 1.13 1.28 1.48 216 1.75 1.34 1.10 103 1 63'1 0.89 1.44 1.10 1.72 to to -I 2.99 2.58 3 88 2.61 1.58 0.99 1.27 Sulphuric Acid. o 8S0' 210' 950' o o p b to O< cn O'OOO IO o< .018 .022 .030 .046 .010 loso' 1 o o o o KO W W O O K tO .023 1 004 .0041 .004 .008 .074 .032 .038 Iron. CO Qi 81 109 j 284 118 511 307 201 445 352 449 366 613 10 tO 144 145 347 1,089 40 49 242 5,479 214 511 Bacteria Per Cubic Centimeter. (Parts Per 100,000.) RESULTS OF ANALYSES. 259 Sand Filter No. 3. (Parts Per 100,000.) 1 1258 1288 13 IS 1348 1380 1 0171 Hol 0611 2911 1069 1088 1112 1139 948 972 995 1024 1045 CD CD GO CO tO CD ^1 >- to Serial Number. Av'gs, Av'gs, July 5 " 11 " 18 " 25 Av'gs, | June 6 " 13 " 20 " 27 Av'gs, May 2 " 9 " 16 " 23 " 31 Av'gs, 1898. 1 Apr. 4 " 11 • " 18 ; " 25 Date of Collection. 1 .023 ' ! .000 .000 .023 .075 .015 .001 . . . n 888^ 288^ .012 .009 .005 .022 .013 .011 .001 .006 .007 .028 .015 .006 II 1 .015 .001 Clear .001 Turbidity. _&< - o - c 5< o § CR CR O .05 .00 .05 .10 .05 k-A .05 .05 .10 20 .12 p 0 0 0 Color. 1 .0049 88888 O' Q O' 4- ** to O o O to .0057 .0098 .0044 .0050 .0036 .0060 .0060 .0070 .0058 .0052 9W .0052 .0054 .0058 0036 .0032 J .0046 i: 0050 .005(1 .0032 .0048 Albuminoid Ammonia. Nitrogen as, ,0025.0000 0480 2.56 .0016 .0028 .0030 .0022 .0028 b to .0028 .0028 .0020 .0020 0014 .0014 0022 .0006 .0016 .0011 0016 .0014 0010 .0008 .0006 0021 i,0008 ' 0020 i.oois .0040 Free Ammonia. 1 II 0000.045014.52 0000 .0525 2.68 .0000.0675'2.75 .0000.0225 1.28 .0000.052511.58 0000 1 o o o o o o o o o o o o o o o o :0000 1 .0000 .0000 .0000 .0000 0000' 0000' 0000' 0000' 0000 0000' .0000 b b b 0 §888 Nitrites. .07692.37 1 ' 1 0900 1.56; .090012.001 .0675 3.281 .06002.66: .0319 .0300 0225 .0225 .0525 8 CH CH .0225 .0225 '.0075 .0300 .0450 .0469 .0525 '.0675 .0375 '.0300 1 Nitrates. 2.16 1.90 2.21 2.10 2.42 h 1.20 1.22 1.50 1.02 1.32 61 1 0 95 1.40 1.52 1.80 II Chlorine. 12.1 17.0 15 3 11.2 9.0 8.2 13.5 9.6 10.8 15.8 18.0 Fil 10.0 11.6 11.8 12.4 30 LO CO GO 00 ^7 00 io to co do b CO b CO CD ^7 CO co b b 4- Total. Residue on Evapora- tion. 0.0 1 p p p p p 0.0 00 0'0 0'0 0'0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 I 0.0 Suspended. 4.2 4 8 5.1 4.0; 3.8 3.2 4.4 4.0 5.7 5.4 1 0*t 2.8 4.4 4.7 4.2 co Z-i 3.2 1.8 2.8 4 0 3.8 3.0 4- 0 to bo Loss on Ignition. 5.24 p p- p -<J b Cn b b w O cn co 4^ to CR -I 4.10 4.68 7.14 7.17 4 58 4x 4^. 4x *4^ 4^ ^7 GO o o to O 3.81 3.77 3.68 3.68 3.70 4.21 5 I 3.22 3.44 3.64 1418 Total Hardness. 4^ 5.41 4.20 3.90 3.20 3.50 4.39 4.00 4.52 5.10 3.94 4.30 : 4.20 4.50 4.21 4.28 CO 3.10 , 3.12 3.60 3'41 3.02 2.40 2.99 3.00 3.7C Alkalinity. CO o 1.72 2.06 1.23 1.13 0.34 cn 4^ 0.17 1.00 1.88 3.13 1 1.04 1.00 1.36 ,0.85 10.95 0.74 do Cn cn co O' to to 4^ 0 tn |o.99 113 1.54 0 92 Sulphuric Acid. , .004 .004 .002 .004 .004 004 .004 200 100 100' r .003 .002 .001 .008 1.002 no- I .008 .008 010 .020 .009 to 025 .008 .008 .008 Iron. w 55 44 50 240 74 GO CO no ; 104 1 57 62 ^7 H4 120 52 38 76 50 41 1m0 71 44 pr 116 81 64 46 Bacteria Per Cubic Centimeter. APPENDIX NO. 2. 260 EFFLUENT-WARREN FILTER. Samples of the "Effluent" from the "Warren Filter" were collected twice a week, from the time it was put into operation until June I, 1898, and then once a week until the close of the experiments. The samples were collected from a quarter-inch petcock, tapped into the effluent pipe between the .filter basin and automatic weir. Samples were collected August 15 and August 29, 1898, from the water as it passed from the Settling Basin to the Filter. Effluent- Warren Filter. (Parts Per 100,000.) OO co CO co GO GO ^7 ci to - o o go 702 709 731 733 742 751 761 770 779 654 655 676 693 Serial Number. Av'gs, Mar. 4 " 7 " 11 11 14 " 17 " 21 " 25 " 28 Av'gs, Feb. 1 " 3 " 7 " 9 " 14 " 18 " 21 " 25 " 28 Av'gs, 1898. Jan. 13 " 13 " 20 " 26 Date of Collection. .000 .000 .000 .000 .000 .000 .003 Clear .000 .003 .000 .000 Clear .000 .000 .000 .023 .000 .000 .000 V.sl'gt V. " .000 .000 Turbidity. 8 .00 .00 .00 .00 .00 .00; .00 .00 o .20 .12 .00 .00 .05 .00 .00 .00 .00 h-I .20 20 .00 .00 Color. .0039 .0028 .0028 .0028 .0030 .0046 .0040 .0068 .0044 9900* .0038 .0038 .0032 .0042 .0060 .0048 .0164 .0040 .0032 .0047 1.0062 .0052 .0040 .0036 Albuminoid Ammonia. .0015 .0022 .0016 .0012 .0014 .0010 .0016 .0014 .0016 0500' .0020 .0014 .0022 .0026 .0020 .0014 .0018 .0028 .0016 .0027 .0050 .0030 .0020 .0010 Free Ammonia. o 'oooo .0000 .0000 0000 .0000 .0000 .0000 0000 .0000 0000' ooooooooo ooooooooo ooooooooo £000' 0006 .0008 .0000 .0000 Nitrites. ft .0487 .0375 .0525 .0525 .0525 0450 .0450 .0600 .0450 CO ^7 CM .0675 .0600 .1500 .1575 .0450 .0450 .1219 .1425 .1500 .0750 .1200 Nitrates. 1.29 1.40 1.31 1.52 1.06 1.20 1.62 1.03 1.20 12'1 1.06 1.50 1.78 1 88 1.18 1.20 1.18 1.12 11.14 1.13 1.20 1.35 0.90 Chlorine. ^7 CO 8.0 8.4 7.2 6.4 5.4 6.8 12.0 8.0 c y 7.2 7 6 6.8 9.2 7.0 7.2 8.4 8.0 8.0 10.2 11.2 11.2 10.4 8.0 Total. 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Suspended. 0 5® z 2 ® 'To 2 IC co 3.2 2.0 2.8 2.4 1.6 1.6 3.2 2.0 co I-I tC 4- IC t-o tO 4^ to to CO *30 OO O 4^ 4- Q O 4^ CM 4^ 4^ o to o to Loss on Ignition. 1.94 1.68 2.80 2.94 2.00 1.94 1.24 1.28 1.62 2.04 1.64 2.14 2.20 2.80 2.12 1.98 1.43 2.18 1.90 ^7 co 1.86 1.78 1.60 1.90 Total Hardness. sn 1.20 1.70 1.80 1.10 1.22 0.98 0.45 0.74 to co 0.90 1.53 1.49 2.01 101 1.11 0.86 1.15 1.04 0.90 1.16 0.94 1.00 0.51 Alkalinity. 2.00 1.51 1.82 11 82 '0 89 0.72 1.51 6.39 1.37 co 1.47 1.03 1.72 1.75 1.13 1.68 1.72 1.36 1.89 1.54 1.89 2 09 1.10 1.10 Sulphuric Acid. 1 .007 '.008 1.006 .006 .004 .004 .016 .006 .006 .009 .010 .020 .008 .010 .006 .004 .008 .006 .006 .021 008 .008 1.066 .004 Iron. 207 )-> to 4* 4*. i-' 00 • OCDOi WOi Cl 00 . 010)0 0101 243 128 378 72 280 265 437 115 269 1,527 2,276 2,276 323 1,234 Bacteria Per Cubic Centimeter. I EESULTS OF ANALYSES. 261 Effluent- Warren Filter. (Parts Per 100,000.) 1 . 1070 1091 1113 1140 O O O' C O O C O c c to tOli O OX W '1 ^1 O Ct Cl O. O' ot Ui rooiCtro^oiMwaoiWHOOco CDCOCOCOCOOOOOCOOO -i- i< tc h- o o x ' ro O©O HO WWOl W Serial Number. Avg's, June 6 " 13 " 20 " 27 Av'gs, May 1 " 2 " 3 " 4 " 5 " 6 " 7 " 9 " 10 " 12 " 13 " 16 " 16 " 23 " 31 Av'gs, - - - - - € 5 • CO to to to 9° ©QUO00C3H0CAM Date of Collection. .000 .000 .000 .000 .000 .005 .002 .002 .001 .002 .002 .015 .000 .000 .000 .000 .000 .011 .011 .000 .035 .000 .000 .000 .000 , .000 .000 Clear .000 .000 .000 Turbidity. o OS .10 .05 .05 .05 .05 .12 .05 .05 .00 .10 .00 .05 .00 .00 .05 .00 .00 .15 .00 .20 2 .00 .00 00 .00 .00 .00 .00 .00 .10 Color. .0049 .0048 .0046 .0040 .0064 .0052 .0060 .0068 .0050 .0054 .0054 .0050 .0048 .0056 .0050 .0034 .0040 .0068 .0064 .0040 .0048 .0041 .0036 .0042 .0048 .0042 .0032 .0038 .0030 .0042 .0058 Albuminoid Ammonia. Nitrogen as. .0015 .0018 .0016 .0010 .0016 .0014 .0008 .0010 .0020 .0018 .0022 .0016 .0018 .0016 .0012 .0016 .0012 .0020 .0008 .0006 .0004 .0016 .0014 .0012 .0012 :,0012 :.0018 0022 .0016 .0026 .0016 Free Ammonia. .0000 .0000 .0000 .0000 .0000 .0000 ooooooooooooooo OOOOOOOOOOOOOOO ooooooooooooooo ooooooooooooooo g .0000 .0000 .0000 .0000 .0000 .0000 .0000 .0000 .0000 Nitrites. s o .0225 .0450 .0150 .0450 .0285 .0300 .0300 .0075 .0150 .0225 .0075 .0225 .0225 .0300 .0150 .0225 .0075 .0075 .0375 .1500 .0467 '.0450 .0600 .0525 .0600 .0600 .0300 .0300 .0375 .0450 Nitrates. to 1-t 1.80 2.50 1.70 2.46 1.38 1.30 1.18 1.30 1.22 1.30 1.42 2.01 0.98 1.08 1.38 1.50 2.30 1.42 0.87 1.38 1.19 h s ifi b k> k> h a> wwooooooooo Chlorine. 10.2 8.8 11.1 9.9 11.0 8.2 7.6 8.0 6.0 8.0 8.8 9.6 7.6 9.6 9.6 8.4 8.4 8.6 9.2 7.2 6.6 7.9 p p ^4 .CO p Cl 00 ^4 CO Ui do Ui co k> do co t© o Total. Residue on Evapora- tion. 0.0 0.0 0.0 0.0 0.0 0.0 ooooooooooooooo ooooooooooooooo o ppooooooo o o o o o o o o o Suspended. 3.3 2.4 3.0 3.8 3.9 2.8 CO CO CO bo bO bO 4^ co to tO to to to co to o o to 4^ co o to o do bo o o bo bo 2.6 2.4 2.4 2.0 ' 1.6 4.0 3.6 1.2 3.2 2.8 Loss on Ignition. 4.06 4.40 4.88 3 65 3.30 2.66 2.08 2.68 2.33 2.18 2.68 102 2.98 3.62 2.62 2.80 3.01 3.25 3.20 2.80 2.60 1.86 1.38 2.18 1.80 2.18 2.06 2.16 1.28 2.64 1.04 Total Hardness. tO 2.00 2.40 1.50 2.50 1.48 1.78 2.10 2.01 1.90 2.15 0.72 1.00 0.42 0.62 1.62 1.30 2 00 2.00 0.58 2.03 1.31 0.65 1.12 1.21 1.60 170 1.71 0.90 2.13 0.80 Alkalinity. CD _ CO . 1.75 2.12 2.24 1.61 1 TFT 0.21 0.49 0.31 1.04 0.58 2.38 2.34 3.03 2.38 1.30 1.75 1.20 1.72 1.95 0.96 ZF1 H H W H h- Q p W Mwdobkb><»<)b OOWWWOiW©© Sulphuric Acid. 003 .002 .002 .004' .003 .014 .028 .024 .030 .024 .024 .004 .002 .004 .002 .002 .002 .006 .024 .002 .028 .005 .004 .008 .008 .006 .006 .002 .002 .006 .004 Iron. CD CH I-4 CO GO CD *4 445 Cn >-1 CO 00 Cl O ~ T CO »-' co®© HHwaoirfxoMoo oooocotcwcotctcooooo cd Ox 220 100 106 155 45 20 39 137 34 Bacteria Per Cubic Centimeter. APPENDIX NO. 2. 262 Effluent-Warren Filter. (Parts Per 100,000.) J-t t-I 1-J )-l p-1 k-1 k-I _1 ►-4 _l 326 383 259 289 319 349 381 166 191 212 Serial Number. Av'gs, Aug. 15 " 29 Avg's, Aug. 1 " 8 " 15 " 22 " 29 Av'gs, July 5 " 11 " 18 1 1898. Date of Collection. O GO . . O ST b O O O O O 8 8 F Turbidity. o o o o o o o CO Ox OX CH Ox .05 .05 .05 .05 .05 b .00 00 .00 Color. .0060 o ' .0051 .0054 0058 .0048 .0048 .0048 .0045 .0040 .0052 .0044 Albuminoid Ammonia. Nitrogen as, .0024 ... .0024 .0032 .0024 .0048 .0040 0024 .0022 .0018 .0016 .0018 .0020 Free Ammonia. a3 i 1 0000 .0000 .0000 .0000 .0000 0000' .0000 .0000 .0000 Nitrites. Oi IO o< .0525 (tied .0450 .0525 .0525 0600 .0225 .0375 | 00Z0' .0675 .0750 .0675 Nitrates. CD IO 2.25 1.60 Watt 2.34 3.95 2.68 2.18 1.36 1.52 2.32 1.66 2.20 3.10 Chlorine. to O 4- Ha 15 13 10 7. 11 I-1 Ci O GO Total. ~ & - 02 4x tO ^7 4^ IO o Ox O io co ^2 to 3.6 0.6 9'0 0.0 0.0 0.0 0.0 3.0 p b b b Suspended. b 3 o d Loss on ignition. co 3.4 2.8 3.2 tO tO JO CO 4^ 00 Ci Ci GO o £-4 Ox CO CO > ox o ■z 3.51 3.58 3.44 4.02 5.71 4.02 3.82 2.92 3.64 3.83 3.20 3.90 4.40 Total Hardness. 1.92 1.95 1.90 1.65 2.42 2.33 1.40 0.40 1.70 to to 1.72 2.54 3.00 Alkalinity. 1.51 1.75 1.27 219 H LO to H t o hL 00 CH kl 00 4*. CO O* co to p o o go CO co co Sulphuric Acid. 600 010' 800' 1 .002 b b b b o o o o o o to to to to to .002 SOO' S00' !S00' Iron. to - co >_1 to ,240 ,120 ,370 350 51 ,530 86 21 52 870 ,300 125 185 Bacteria Per Cubic Centimeter. EFFLUENT-JEWELL FILTER. Samples of the "Effluent" from the "Jewell Filter" were collected twice a week, from the time it was put into operation until June I, 1898, and then once a week until the close of the experiments. The samples were collected from a half-inch petcock, tapped into the effluent pipe between the filter basin and the gate. Samples were also collected August 15 and August 29, 1898, from the water as it appeared upon the surface of the filter. RESULTS OF ANALYSES. 263 Effluent-Jewell Filter. (Parts Per 100,000.) 863 876 883 893 901 912 921 930 941 CO CO CO 00 CO CO CO '1 Oli^WWWOOOO 4^ to cn cn o as o -i 703 710 730 732 750 752 764 771 780 677 694 Serial Number. i, Av'gs, Apr, 1 1 " 4 " 8 " 11 1 " 151 " 18[ " 22 '• 25 | " 29 । Av'gs, Mar. 4 " 7 " 11 " 14 " 17 " 21 " 25 " 28 Av'gs, Feb. 1 " 3 " 8 " 9 " 16 " 18 'f 21 " 25 " 28 Av'gs, 1898. Jan.21 " 26 Date of Collection. « .000 . . . Q cocyoooco Q p o 2 o o o o o oo o o o o a o .001 .009 .000 .000 .006 .000 .003 Clear .000 .008 .000 1 .000 Clear .000 .045 .000 .023 .000 .000 .000 Clear .000 Turbidity. g .00 •00 .00 .00 .00 .00 .00 .00 .00 •o .00 .00 •00 •00 •00 ■00 .00 .00 .10 .07 .00 .00 .25 .10 .10 .00 .10 8 ..00 .00 Color. 0042 .0042 .0046 .0042 .0040 .0036 .0030 .0034 .0044 .0064 .0035 .0022 .0030 .0026 .0032 0038 .0040 .0056 .0038 .0038 .0030 .0032 .0040 0038 .0060 .0046 .0032 .0038 .0030 0034 .0042 0026 Albuminoid Ammonia. Nitrogen as, 0018 0016 .0014 .0026 .0012 .0020 .0020 .0018 .0016 .0016 .0015 .0016 .0016 .0012 .0014 .0012 .0016 .0018 .0016 .0017 .0020 .0016 .0026 .0018 .0010 .0010 0020 .0022 .0008 M00' .0014 .0014 Free Ammonia. |oooo bbbbbbbbb oocoooooo 000008000 .0000 .0000 .0000 .0000 .0000 .0000 .0000 .0000 .0000 .0000 .0000 .0000 .0000 .0000 0000 .0000 .0000 .0000 .0000 1 if Nitrites. 0475 .0525! .0600! .0450 0525 .0600 0375 .0375 .0375 .0450 .0534 .0450 .0750 .0525 .0525 .0450 .0450 .0525 .0600 .0862 i .0600 .0675 .1425 .1350 .0750 .0375 j.0787 L0450 31125 Nitrates. 1.22 0.88 1.00 1.32 1.32 1.54 1.46 1.00 1.38 1.05 1.17 122 1.30 1.51 1.05 1.08 1.56 0.70 0.98 1.31 0.98 1.55 1.70 1 80 1.18 1.20 1.29 1.16 0.96 0.92 0.98 0.86 Chlorine. bo O GO COCO CD pOCOCM bo 6.8 7.6 7.6 64 6.4 8.4 6.6 8.4 1 00 7.2 9.2 72 8.8 6.4 6.4 8.0 8.6 8.2 GO bn 10.2 6.8 Total. Residue on Evapora- tion. p 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 oooooooo b b b b b b b b p 0.0 0.0 0.0 0.0 0.0 0.0 00 00 Q.O 0.0 0.0 Suspended. to 1.8, 12 2.0 2.8! 4.4 2.8 2.0 2 0 2.8 to 1.8 2.4 3.2 2.0 2.0 3.2 1.6 2.8 co 9'2 f 6 p 8'z FS Z'f CO bo 4.8 2.8 Loss on Ignition. 1.93 1.32 1.86 188 2.14 2.28 180 2.18 2.50 138 2.09 1.80 2.78 3.22 2.06 2.21 1.32 1.69 1.68 2.27 1.91 2.04 2.72 ! 2.88 ! 2.18 ! 1.80 2 64 2.31 1.98 O to to o 4- CO Total Hardness. 1.44 0 60 1.08 1.46 1.65 1.84 1.51 1.72 2.05 1.02 b 1.32 1.71 2.10 1.20 1.25 0.80 0.48 0.80 WT 0.93 1.45 1.84 2.13 1.29 1.09 1.32 1.40 1.20 0.88 1.05 0.71 Alkalinity. to h-1 1.61 0.44 0.82 1.31 1.48 1.23 1.52 138 1.08 1.59 1.65 1.72 1.82 0.82 1.03 1.37 3.00 1.30 1.38 1.47 1.10 1.52 1.37 0.89 1.47 1.74 1.38 1 51 r-' 68'1 IS'l Sulphuric Acid. 008 .009 .006 .008 .008 .006 .020 .004 .008 004 .006 .009 .004 .006 .008 .002 .008 .006 .006 .010 1.008 .006 .010 006 .040 .004 1.006 006 .006 800' .002 1004 Iron. 179 283 152 91 124 145 81 45 570 124 175 100 89 109 462 252 118 98 741 293 481 1,075 3,413 271 134 117 145 . 2,753 5,114 393 Bacteria Per Cubic Centimeter. 264 APPENDIX NO. 2. Effluent-Jewell Filter. (Parts Per 100,000.) Av'gs, 1327 Aug. 16 Slight 1384 " 29 j Av'gs, .000 1260 Aug. 1 .000 1290 " 8 .000 1320 " 15 .001 1350 " 22 .000 1382 " 29 .000 Av'gs, .000 1167'July 5 Clear 1192 " 11 .000 1213 " 18 .000 1241 " 25 .000 Av'gs, .003 1071 June 6 .000 1092 " 13 .000 1114 " 20 .012 1141 " 27 .000 Av'gs, .000 1898. ! 951 May 2 .000 964 " 5 .000 974 " 9 .000 988 " 13 .000 997 " 16 Clear 1026 " 23 .000 1047 " 31j .000 Serial Number. Date of Collection. Turbidity. H-1 o .15 .17 £ .00 .05 .05 .05 .05 b . b b h b O cn O O', o O' .05 .10 .00 .05 b .07 .00 t00 .00 .00 .00 .00 Color. .0058 .0064 .0062 .0060 .0048 .0056 .0047 .0056 .0050 .0040 .0042 b .0052 .0044 .0042 .0062 .0040 .0032 .0052 0042 .0038 .0050 .0032 .0032 Albuminoid Ammonia. .0027 .0022 .0040 .0020 .0024 .0028 .0017 .0018 .0016 .0018 .0018 IS00- 0026 .0030 .0010 .0020 .0013 .0010 .0016 .0014 .0016 .0020 .0004 .0008 Free Ammonia. o up .0000 .0000 .0000 .0000 .0000 .0000 .0000 o o o o o o o o oooo o o o o oooo- OOOO oooo 8888 b § .0000 .0000 .0000 .0000 .0000 .0000 .0000 Nitrites. a % ... 1.79 ... 2.28 . . 1.30 tiled .0435 2.45 .0525 4.12 .0375 2.80 .0600 2.35 .0225 1.48 .0450 1.50 .0600 2.40 .0600 1.60 .0750 1.98 .0600 3.40 .0450 2.62 .0319 2.03 .0375 2.12 0300 2 20 .01501.50 .0450 2.30 .0214 1.36 .0225 1.14 .0150 1.36 .0150 102 .0150 1.32 .0075 2.40 .0300 1.18 .0450 1.10 Nitrates. Chlorine 00 13.6 10.0 7* 11.6 15.9 13.0 10.8 7.6 10.8 13.6 12.1 10.4 15.8 16.2 10.4 9.0 11.6 9.4 11.6 p p p p M O p M bi bo co to bo to o Total. Re Ex do 2.8 0.8 to o o o p wobbo o o p p p o oooo o o o o p b b b b o p p o o o o o b b b b b b b Suspended. SIDUE ON rAP0KA- k TION. " 3.2 4.11 3.5 3.94 3.0 4.28 3.7 3.87 co co oo to b 4^ to do p to p CO p CO 00 o co O' 4- K O 4.3 4.57 4.2 3.56 3.0 4.52 5.2 4.80 4.7 5.40 3.3 3.83 rfx co co to b4 4c. p p p p ►-1 bi CZ) 00 o CO 2.9 262 2.6 1.98 2 8 1.90 3.8 2.74 2.0 2 55 3.2 3.18 2.8 3.20 3.2 2.82 Loss on Ignition. Total Hardi p s io co 2.001.72 2.120.75 2.101.72 3.501.85 2.661.61 1.761.79 0.701.95 1.901.41 to 4^ OP to to co 1.941.2C 2.621.65 3.282.69 2.103.37 1.912.11 1452.34 2.212.51 1.951.65 2.021.95 1.491.42 1.601.47.008 32 1.401.54.004 11 1.301.79.006 115 1.781.13.002. 50 1.901.20.004 770 0.941.47, .003 310 1.531.34.002 23 Alkalinity. Sulphuric Acid. 010 2,130 .008 2,870 .0121 1,400 .002 165 88888 tO tO tO tO IO 4- OC1 HOCD CH C3 O C2< .003 285 1.008 610 ..002 190 L002 265 .002 67 .003 230 .001 16 .002 420 >004 185 >.004 300 1.004 185 Iron. Bacteria Per Cubic Centimeter. RESULTS OF ANALYSES. 265 APPLIED WATER-WORMS TILE FILTER. Samples of the water applied to the "Tile Filter" were collected once a week from the time it was placed in operation until the middle of February, 1898. After this and during the operation of the second test, samples collected from the "Gate Chamber" were considered suffi- ciently representative of the water applied to the Worms Tile Filter. These samples were collected from the inlet pipe as the water flowed into the Settling Tank. Applied Water-Worms Tile Filter. (Parts Per 100,000.) 722 743 0.0:0 0 00 *4 CB co o to o w 548 565 579 601 618 531 Serial Number. Av'gs, Feb. 8 " 15 Av'gS, 1898. Jan. 6 " 12 " 20 " 26 Av'gs, Dec. 1 " 10 " 15 " 22 " 30 1897. Nov. 27 Date of Collection. 0.14 p p io O 0.25 poop tO 4-1 CH O 0'10-14- 0.27 0.24 Slight, 0.38 0.40 0.05 60'0 Turbidity. to .30 .25 io co co co to o OOP io .30 .25 .30 .30 .30 .30 Color. .0075 .0068 .0082 .0084 .0064 .0116 0088 0068 .0097 .0128 .0102 .0110 .0092 .0052 .0136 Albuminoid Ammonia. Nitrogen as, .0020 .0022 0018 .0019 o o o o o o o o H H W M o o o o .0022 .0040 0022 .0016 .0016 .0018 1100' Free Ammonia. .0000 .0000 .0000 0000' .0000 .0000 .0000 .0000 .0000 .0000 .0000 0000 .0000 .0000 I Nitrites. .1012 .1500 .0525 0994 .0675 .1350 .0750 .1200 .0750 .0750 .0675 .0825 .0750 .0750 .0525 Nitrates. 1.54 1.58 1.51 1.74 2.39 2.03 1.51 1.03 1.80 N H H H h* P-* 44 CD CO CH O Cl 44 O CO 2.86 Chlorine. 16.5 20.2 12.8 >-4 13.6 20.0 13.6 11.6 13 7 to p o Total. Residue on Evapora- tion. p< 44 ca do 44 tO CH 0.0 5.6 0.3 4.0 to CH 1.6 0.4 3 2 7.2 0.0 CO do Suspended. CH . do 8.4 3.2 5.4 WO® Ot to do 44 io pl 3.6 4.8 6.0 5.6 4.8 p do Loss on . Ignition. 2.78 3.18 2.39 1.88 2.38 2.02 189 1.22 2.56 2.10 3.16 2.90 1.98 2.64 4.02 Total Hardness. 2.05 4^ O Cn Ox 1.54 2.05 1.70 1.42 1.01 1.90 H H KI W H CO io 44 o co 00 to to co 3.68 Alkalinity. 1.01 1.58 0.44 1.41 1.92 168 1.06 0.99 1.34 0.72 0.96 1.61 1.89 1.51 03 p> Sulphuric Acid. .119 .100 .138 .142 .056 .168 .186 .160 .138 .162 .108 .138 .204 .080 .070 Iron. 13,850 3,550 24,150 11,844 3,950 16,125 12,300 15,000 | 16,270 23,300 25,700 15,400 13,050 3,900 17,800 Bacteria Per Cubic Centimeter. 266 APPENDIX NO. 2. SETTLED WATER-WORMS TILE FILTER. Samples of the water, which had been settled by the addition of the chemical and passage through the material in the settling tanks, were col- lected once a week, from the beginning of the test upon this filter until the first of April, 1898. In June, when the test was renewed, we began to collect these samples once a week and continued until the close of the experiments. These samples were generally collected during the first test from a quarter-inch petcock, tapped into the three-inch pipe, leading from Sett- ling Tank No. 3 to Filter Tank No. 5. During the second test, they were collected from the surface of the water in the Filter Tank No. 5 : with the exception of the sample, dated August 8, 1898, which was collected from the surface of Filter Tank No. 6. Settled Water-TForms Tile Filter. (Parts Per 100,000.) 634 652 673 690 549 566 580 602 619 532 Serial Number. Av'gs, 1898. Jan. 6 " 12 " 20 " 26 Av'gs, Dec. 1 " 10 " 15 " 22 " 30 1897. Nov. 27 Date of Collection. Clear Slight V.sl'gt Clear Slight ( c V.sl'gt Slight Turbidity. .10 .30 .20 '.25 io co co to CO tO H-4 O O 0 0'0 co Color. 8 CH GO 0056 .0056 .0082 .0040 ) 0075 o o o o o o o o o o Ot^lQOOOO O CO 00 GO Ob .0080 Albuminoid Ammonia. Nitroc 0500' .0020 .0038 .0014 .0010 .0016 .0032 .0016 .0012 .0012 .0008 .0010 Dree Ammonia. .0000 o o b o §888 .0000 .0000 .0000 0000 .0000 .0000 .0000 Nitrites. 1EN AS .1181 .0825 .1800 .0825 .1275 .0810 .0900 .0675 .0900 .0675 .0900 .1050 Nitrates. 1.80 2.16 1.71 1.57 1.76 2.48 4.72 1.99 2 22 L31 2.15 GO O Chlorine. 0S1 GO CO p p GO bO O O 15.5 27.2 11.6 14.0 12.0 12.8 20.4 Total. 1 p 00 06 0.0 0.0 p 0.0 0.2 0.4 0.0 0.6 Suspended. g > g Hi pt O 6.0 6.0 8.0 3.8 p co p p p p p to bo co 8.0 Loss on Ignition. ■ § to eg 3.21 2.16 2.36 1.48 3.51 to to CO CO p io io co o CI CO CO QO 3.76 Total Hardness. | 1.97 2.97 1.85 1.79 1.29 2.90 5.43 2.15 2.84 1.90 2.16 3.42 Alkalinity. 1.37 2.13 1.65 0.89 0.82 1.31 1.02 1.03 172 1.37 i.ei Sulphuric Acid. .098 o to o o .104 .020 .152 .100 .156 .090 .110 Iron. 699*9 2,675 5,300 6,600 12,100 6,444 4,200 11,375 6,975 3,225 Bacteria Per | Cubic Centimeter. ; RESULTS OF ANALYSES. 267 Settled JVater-Worms Tile Filter. (Parts Per 100,000.) 1261 1291 1321 1351 1169 1193 1214 1242 1089 1121 1144 873 797 817 832 851 706 723 744 762 781 Serial Number. Av'gs, Aug. 1 " 8 " 15 " 22 Av'gs, July 5 " 11 " 18 " 25 Av'gs, ! June 13 " 20 " 27 Apr. 4 Av'gs, Mar. 7 " 14 " 21 " 28 Av'gs, 1898. Feb. 3 " 8 " 15 " 21 " 28 Date of Collection. Clear u H U V.sl'gt Clear 4c C c Clear IC V. sl'gt Slight Slight V sl'gt Dec'd 1 Slight W'A Turbidity. to p to o IO O O O' .09 .10 .10 .12 .05 b O H-1 O On O Ox to O' to to to to to o o io o' 5 .20 .25 .17 .10 22 Color. .0058 .0060 .0060 .0068 .0044 .0049 .0044 .0054 .0052 .0048 .0069 .0042 .0098 .0068 b o oo .0076 bbbb t-1 to to 4^- o to 4^ 00 .0058 88888 ^Q^OiQ Ob GO IO tO tO Albuminoid Ammonia. Nitrogen as, .0016 .0012 .0014 0016 .0024 noo1 .0020 .0018 .0016 .0016 .0013 .0010 .0018 .0012 S100' .0013 .0012 .0012 .0014 .0014 .0020 .0014 .0028 .0018 .0032 .0010 Free Ammonia I iiii b s 0000' 0000' 0000' 0000 0000' .0000 loooo .0000 .0000 | .0000 0000 .0000 .0000 .0000 o o o o p o o a o o o o o o o o o o o o Nitrites. .0431 । 0450 । .0450 1.0525 >.0300 O' po I 0675 .0675 .0525 .0450 0880* .0525 .0150 .0375 0090' - .0450 .0450 .1050 .0525 00 LO CJ' .0975 .1425 .0525 .0375 Nitrates. 4.18 5.70 4.30 3.00 3.74 4 79 4.55 3.79 5.65 5.18 3.94 13.70 3.60 4.52 1.96 to 1.65 2.80 2.00 3.51 2.58 1.62 4.34 3.08 2.38 1.48 Chlorine. 16.8 20 2 17.0 14.6 15.6 18.6 15 5 13.2 23.6 22.2 14.0 14.0 14.0 13.9 10.8 12.3 12.6 13.6 13.8 9.4 12.8 tO»- p to co to p O O GO 4^ CO Total. Residue on Evapora- tion. o o o o o o o o p o o o o o o o o to 0.0 I 0.0 0.5 0.2 p p p o o to to b to p 0.0 2.4 0.2 0.2 0.0 Suspended. 5.8 60 50 4.6 7.6 o 00 5.6 40 7.8 8.0 O'S ►4- © Ox o b b 3.6 CO GO 4.0 4.8 4.0 2.4 O' to 4.8 11.6 2.2 4.4 3.2 Loss on Ignition. rf*. co 5.54 4.18 5.70 4.05 4.91 4.26 4.65 4.90 5.85 3.42 2.60 4.05 3.60 2.00 to ^1 3.22 2.88 2.34 2.63 2.85 3.12 3 24 2.18 3 28 2.42 Total Hardness. to s 2.48 1.88 3.22 0.64 1.74 1.10 210 2.07 1.68 1.79 2.51 1.50 . 1.35 1.40 I1'71 2.14 1.66 1.55 1.51 1.71 2.56 0.90 1.20 2.03 1.86 Alkalinity. 1.34 0.89 1.82 0.52 1.46 0.17 1.13 1.75 2.78 r-1 to 1.47 0.75 0.85 96'0 GO co 1.51 0.55 0.37 0.89 r-4 CO 1.27 1.27 0.55 1.07 1.48 Sulphuric Acid. 8 .004 .002 :.006 .006 .010 .016 .016 .006 .002 Z00' .002 .008 .012 .048 031 .022 .020 .074 .008 .090 070 .246 .046 .074 .016 Iron. 430 520 710 400 88 465 co Ob Cb to h-4 00 O' co oooo S8t 690 640 120 550 2,383 4,100 2,650' 400 3,750 jo jo "7-* To 7-* to o Cn Q O Cn © © © © © Bacteria Per Cubic Centimeter. 268 APPENDIX NO. 2. EFFLUENTS-WORMS TILE FILTER. Samples of the "Effluents" from the tiles were collected about once a week during both tests. During the first period they were collected from the effluent from Tile A, except upon April 4, 1898, when the effluent from Tile B was sampled; both of these tiles were supplied with chemically treated water. Also from Tiles D and E, which were supplied with untreated water. During the second test all tiles were sup- plied with chemically treated water, and the samples were collected from the effluent from Tile B; except upon June 13 and August 29, 1898, when the effluents from Tiles A and E, respectively, were sampled. These samples were collected, during the first test, and until July 12, 1898, during the second test, from quarter-inch petcocks on the effluent pipes. After the above date the effluent pipes had a free flow and samples were ob- tained from the outlets. Effluent, Tile A-Woivns Tile Filter. (Parts Per 100,000.) 635 651 674 691 550 567 581 603 620 533 Serial Number. Av'gs, ~ ~ CO co bo to >-■ Ct otom <kT Dec. 1 " 10 " 15 " 22 " 30 1897. Nov. 27 Date of Collection. : .075 Clear .120 .030 V.sl'gt V. " V. " V. " Clear V. sl'gt Turbidity. s .00 .00 .20 ■16 .20 .20 L10 .10 .10 to Color. .0056 .0050 .0062 .0080 .0032 .0078 .0110 .0092 .0062 .0064 .0064 Q 00 Albuminoid Ammonia. Nitrogen as, .0017 .0022 .0022 .0014 .0012 .0015 .0028 .0018 .0012 .0010 .0006 .0012 Free Ammonia. .0000 1|§§ .0000 .0000 .0000 .0000 .0000 .0000 0000' Nitrites. .1200 .0900 .1800 .0975 .1125 .0780 .0900 .0600 .0675 .0975 .0750 to ch Nitrates. 1.78 2.36 1.81 1.33 1.63 to co 3.34 2.13 2.34 1.34 2.36 3.15 Chlorine. CO CO 00 tO GO CO bo 4^ oo to 13.5 18.8 11.2 13.2 11.2 13.2 17.6 Total. Residue on Evapora- tion. 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 to Suspended. CH 4^ co 4^ o to o o 5.2 ►4 W Q 4^ CO o to bo o o 0'9 Loss on Ignition. 2.68 3.30 2.90 2.62 1.90 3.34 4.70 3.46 2.82 2.85 2.88 3.70 Total Hardness. 2.13 2.86 2.32 2.00 1.36 2.82 4.09 2.71 2.61 2.20 2.49 3.40 Alkalinity. 1.33 2.47 1.78 0.68 0.41 1.40 * 1 1.10 1.16 1.47 1.72 1.54 kr CH Sulphuric Acid. s to .042 .026 .150 .030 .094 .030 .152 .088 .106 .093 .088 Iron. 2,435 1,237 1,152 2,950 4,400 6,069 11,550 7,663 3,800 1,262 35,350 Bacteria Per Cubic Centimeter. RESULTS OF ANALYSES. Effluent, Tile A-IPorms Tile Filter. (Parts Per 100,000.) 269 636 653 675 692 551 568 582 604 621 534 Effluents, Tiles D and E-Worms Tile Filter. (Parts Per 100,000.) 874 798 818 833 852 707 724 745 761 782 Serial Number. Av'gs, 1898. Jan. 6 " 12 " 20 " 26 Av'gs, o ~ ~ D p CO to t-1 t-L O K) Cl O H 1897. Nov. 27 .April 4 Av'gs, Mar. 7 " 14 " 21 " 28 Av'gs, 1898. Feb. 3 " 8 " 15 " 21 " 28 Date of Collection. Clear Slight V.sl'gt V. " V. sl'gt Clear V.sl'gt V. " Clear V.sl'gt V.sl'gt .015 .010 .000 .015 .034 .069 .003 Clear 1I .135 Turbidity. .10 .20 .10 .30 p M H b b M o O O' CR o to CR to J-1 •o .17 .17 .17 .17 b .20 .00 .05 .00 .12 Color. O 8 .0046 .0044 .0072 .0046 .0082 88882 GCO^OO 8 co .0054 .0043 .0032 .0030 .0060 .0052 .0047 .0048 .0060 .0048 .0040 .0040 Albuminoid Ammonia. Nitrogen as, .0020 8888 1-^ - co l-O to tc GO O s GO b b b b b o o c c o H M K> IO to to .0014 gooo .0018 .0014 .0016 .0020 .0022 .0018 Free Ammonia. 0000' .0000 .0000 .0000 .0000 0000' .0000 .0000 .0000 .0000 .0000 .0000 oooo- 0000' .0000 .0000 .0000 .0000 0000' .0000 .0000 .0000 .0000 .0000 Nitrites. .1106 O CO - I 8 cn to to to O Cn cn o< 5 o .0975 .0600 .0750 .0825 .0750 pssr CR to O' O' to O' .0525 .0450 .0600 .0525 GO to CH .1050 .1350 .0450 .0450 Nitrates. o CO 2.48 1.56 1.56 1.14 1.88 1.55 2.19 2.40 1.27 1.98 i 3.38 ... |8Z Z fS'Z to p p p co bi co b . Cn O O 1 to o C' 1.69 4.20 3.82 2.42 1.10 Chlorine. cr 12.8 13.6 11.2 8.4 11.2 12.0 11.2 10.8 10.8 11.2 O' to o to b CD CO tO CD to to o to 12.0 9.0 19.6 10.6 10.4 10.2 Total. Residue on Evapora- tion. p 0.0 0.3 0.0 0.0 0.0 poppp 0.2 0.0 0.0 0.0 0.0 0.0 P 0.0 o o o o o b b b b b Suspended. 4.9 p 4^ bbbco 4^ to CO CO W Mx p OS b 4- to Mx MX to 4^ 4^ to o bo GO 4^ co b CO 03 4^ CR CO bo to to to to Loss on Ignition. 2.27 p p p p CO to bi (X O 00 4^ 2.58 to to to co to Mbto'^b ^1 GO CO 00 4- 2.88 bo GO 3.34 3.84 3.48 3.21 2.82 2.87 2.88 3.19 2.31 3.07 2.88 Total Hardness. *4 co 2.202.1:; 1.711.78 1.910.81 1.270.65 1.941.28 1 2.010.72 2.101.13 2.001.51 1.721.51 1.861.51 1 2.811.78 1 1.120.48 i p p • CD to to to bo co h-* to oooo p p O M g to bo bo to o g 2.451.44 1.991.70 1.230.30 2.021.38 2.381.17 Alkalinity. Sulphuric Acid. go .032 .110 .136 .060 o o< o .070 .050 .038 .082 .040 .070 .010 .010 .006 .002 .020 .014 to >-I .034 .004 .006 .010 .050 Iron. 4,440 1,987 4,900 7,450 3,425 6,666 18,900 2,963 3,187 1,613 25,175 IL Q 108 116 107 1,675 53 2"1 Co'o 4^^ CR O' O O OOCv'O Bacteria Per Cubic Centimeter. | 270 APPENDIX NO. 2. Effluents, Tiles D and E-Worms Tile Filter. (Parts Per 100,000.) 708 725 746 Serial Number. Av'gs, 1898. Feb. 3 " 7 " 16 Date of Collection. V.sl'gt Clear Slight Turbidity. 03 .20 .00 .20 Color. 8 .0040 .0064 .0044 1 Albuminoid Ammonia. Nitrogen as. 8 o .0014 .0026 .0020 Free Ammonia o .0000 .0000 .0000 Nitrites. s .1050 .12(10 .0600 Nitrates. CT OF I OS'I Chlorine. 9.3 ; 8.8 11.2 8.0 Total. Residue on . Evapora- tion. 0.0 Suspended. CO 3.2 4.0 4.0 Loss on Ignition. 2.72 2.07 3.42 2.68 Total Hardness. 1.80 2.20 1.70 Alkalinity. 1.10 1.54 0.48 Sulphuric Acid. .034 .022 .050 Iron. 512 725 300 Bacteria Per Cubic Centimeter. Effluent, Tile B-Worms Tile Filter. (Parts Per 100,000.) 1898 1090June 13 Clear .00 .0036 .0008 .0000.0300 3.62 13.8 0.0 4.4 2.68 3.12 1.58 .001 525 1122 " 20 .010 .00 .0052 .0018 .0000'.0225 3.60 14.8 0.0 5.6 4.15 1.80 0.68 .006 385 1145 " 27 .000 .05 .0058 .0014 .0000.0375 4.44 15.7 0.0 5.1 3.69 1.50 1.10 .004 285 Av'gs, .005 .02 .0049 .0013 0000.0300 3.89 14.8 0.0 5.0 3.51 2.14 1.12 .004 400 1170 July 5 Clear .10 .0036 .0018 .0000.0825 4.60 15.6 0.0 40 4.70 1.500.17 .008 770 1194 " 11 .000 .05 .0048 .0012 .0000.0600 3.50 13.5 0.0 4.9 4.31 2.511.47 .012 290 1215 " 18 .000 .10 .0040 .0014 .0000 .0450 5,52 23.4 0.0 8.0 4.94 2.181.79 004 185 1243 " 25 .000 .05 .0050 .0016 .0000 .0525 4.30 20.4 0.0 7.0 6.05 2.142.24 1 .002 110 Av'gs, .000 .07 .0043 .0015 .0000 .0600 4.48 18.2 0.0 60 5.00 2.08 1.42 .006 340 1262 Aug. 1 .000 .05 .0062 .0012 .0000 .06005.70 20.0 0.0 6.0 5 93 2.52 1.58 .002 190 1292 " 8 .001 .10 .0060 .0014 .0000 .04503.95 16.8 0.0 4.4 4.06 1.79 1.07 .004 190 1322 " 15 .001 .10 .0068.0020 .0000 .0600 4.30 16.8 0.0 5.2 5.20 2.40 0.92 .002 57 1352 " 22 .000 .10 .0046.0024 .0000 .0300 3.30 11.7 0.0 4.6 4.00 0.650.82 .002 33 1385 " 29 Clear .05 3.00 13.6 0.0 6.2 3.82 1.181.23 .004 Av'gs, .000 .08 .0059.0017 1 l> II .0000.0487.4.05 15.8 1 II 1 0.0 5.3 4.60 1 1.711.12 .003 115 Samples were collected from the "Monongahela River" at this point, about once a week during the months of June and July, 1897; then twice a week, during the months of August to November, inclusive, 1897 ; then once a week, until March 14, 1898; and, finally, once in two weeks during the remainder of the work. MONONGAHELA RIVER-AT INTAKE OF MONONGAHELA WATER COMPANY. RESULTS OE ANALYSES. 271 The water supply, which is furnished to the South Side Wards, Nos. 24-36, inclusive, by the Monongahela Water Company, is taken from the Monongahela River opposite the foot of Twenty-ninth Street. In 1888, an intake was placed in the river, about 400 feet from the south shore and connected to the pump well by a 36-inch pipe. The average daily consumption, in this portion of the city, as given by the Water Company for the year 1897, is estimated to be about 12,000,000 gallons per day. These samples were collected sometimes from the river side of flat boats, moored adjacent to the south bank, a little up stream from the pump station ; also, when a small boat could be secured, the samples were collected farther out in the stream over the intake. Monongahela River-At Intake of Monongahela Water Company. (Parts Per 100,000.) 76 109 120 134 142 159 167 31 37 46 61 7 15 18 29 Serial Number. Av'gs, Aug. 2 " 12 " 16 11 20 ' ' 23 " 26 " 30 Av'gs, July 6 " 12 " 20 " 26 Av'gs, 1 1897. June 10 . " 17 ' " 21 " 30 Date of Collection. Q Q A d < S' - o cki' ~ o CL Qj Dec d Mud'y Mud'y Dec'd Turbidity. r 5: : : : : : Color. .0173 .0160 .0210 .0176 .0152 .0215 .0150 .0148 .0186 .0180 .0136 .0210 .0220 .0136 .0055 .0100 .0270 .0120 Albuminoid Ammonia. Nitrogen as § .0033 .0063 .0039 .0069 .0126 .0138 .0230 .0076 1 .0050 .0092 '.0115 .0046 .0081 .0053 .0160 .0050 .0060 Free Ammonia. s p .0002 .0000 .0000 .0000 .0000 .0000 .0002 .0001 .0000 .0002 .0002 .0001 | 0000' Nitrites. to .1334 .0888 .0600 .0975 .1350 .1500 .1200 .0768 .1200 .0306 .0825 .0741 .0740 .0740 Nitrates. 1.07, .3.40 0.72 ,0-45 0.53 0-61 0.94 0.85 CO 0.30 0.35 0.69 0.40 1.35 0.70 0.40 4.00 0.30 Chlorine. to CO pl p p p p p p o co bo bo to o go h-* 11.6 9.6 16.8 18.5 pl 12.4 10.8 26.0 12.4 Total. Residue on Evapora- tion. to co : 4^ to to to >-• to • o bo cd to bo 3.2 1.2 4.9 I7-2 p to 11.6 1.2 Suspended. 3.6 4^ co CO 4^ to CO CO bobbo^bb p ►-I p p to co o co bo to 4.6 2.8 5.2 6.8 3.6 Loss on Ignition. CH CO 4.45 4.40 6.40 5.61 6.50 6.10 6.68 CO 5.00 4.75 4.93 5.20 7.35 10.50 6.60 8.00 4.30 Total Hardness. 1.95 3.60 2.12 2.22 1.80 1.70 1.91 0.30 bC GO o< 3.00 2.50 3.05 • Alkalinity. 3.01 1.58 1.65 1.72 2.67 3.06 3.92 6.46 2.03 to to to O bo CO bi to o o o 3.51 5.36 2.50 3.10 3.10 Sulphuric Acid. .193 .240 .165 .160 .200 .270 .310 .008 .195 1 09o OSD ... Iron. 5,708 3,750 9,250 4,125 82,970 i 82,970 Bacteria Per Cubic Centimeter. 272 APPENDIX NO. 2. Monongahela River-At Intake of Monongahela Water Company. (Parts Per 100,000.) 426 448 458 478 486 499 506 536 310 331 337 360 367 391 396 419 184 201 221 226 245 251 277 283 301 1 Serial Number. Av'gs, Nov. 1 " 3 " 8 " 10 " 15 " 17 " 22 " 29 Av'gs, Oct. 4 " 6 " 11 " 13 " 18 " 20 " 25 Av'gs, GO i 1 : : : : : to to be to 1-' 1-' r4 O^ICOOOCOOOI-1 Date of Collection. d. U. 22. 22 o : O : p go <! co^225" orcs' p®. cere' 'AtT 2- b p k' 5W < go< 0o?5' 21 P Pere' iE.de' Turbidity. 6r .10 .10 .25 .20 .20 .20 .20 .30 to b b b b b b b to O O' O O Oi O O' o to 05 .35 .20 .20 .05 .30 .20 Color. .0194 oooooooo ^cc^cocct^io^ O 05 O GO O O' O bO b s oooooooo ^OO^bOO^COtO 05 -O' 05 O1O5 4^ 4- OOOGOOOOO 0S10' 000000000 to too toowooto coo ^otooa to 4- Albuminoid Ammonia. Nitrogen as, O' .0210 .0280 .0240 .0210 .0110 .0046 .0044 .0020 1 SHO' .0208 .0180 .0046 .0024 .0180 .0210 .0260 '.0026 k-I CD .0012 .0126 '.0142 .0162 .0118 .0096 .0092 '.0161 '.0160 1 Free Ammonia .0000 .0000 .0000 .0000 .0000 .0000 .0000 .0000 .0000 bbbbbbbb oooooooo 88888888 0000' 888888888 888888888 Nitrites. O CO IO O' .0525 .0750 .1500 .0225 .1350 '0900 '.0900 .0450 .1261 .0750 .0825 .1500 .1425 .2250 .1238 .0900 .1200 s CD .0975 .1125 .0975 .1312 .0900 .0450 .1500 .0900 '.0675 Nitrates. 1.47 1.76 1.93 1.61 1.54 0.97 1.31 1.05 1.58 bi O' bcodobibcobib GC C O D W O 0.95 0.80 0.53 0.95 0.62 1.25 1.21 1.39 0.82 '0.97 Chlorine. bi mwwcdwmo5Co b b k) bo k) b b b to co bi to to to CO CO 1O bD to CD GO p- O' 05 OO 05 to to b io bb b b bi 12.0 42.8 13.6 11.2 14.4 15.8 15.6 15.6 19.2 Total. Residue on Evapora- tion. 6.1 1.2 2.0 0.2 0.4 5.6 6.0 0.6 33.2 :::::::: p Suspended. 7.1 H O' p Q Q 4^ O 4^ to b go b bo bo bo b co b CD GO ^4 Q5 S GO GO P bo to to b b b b b P W 4^ p W P p p p CO 4*. 4^ O to 4^- 4^- 4^ CO Los« on Ignition. 6.25 6.28 7.32 6.18 6.71 5.65 5.80 5.76 6.28 05 b to 6.21 6.70 7.51 6.71 6.23 6.38 Ol CD Cn Ot C5 Ci 05 Cl Ct> 4^ Cn wt.wbiHbbbi^ QiCOCncDCiCntDCOCn Total Hardness. 1.41 WHpMHpnp b b bo b w b co co OOCOCOOcOtOCi o b OppppptOH '^b^bwoobb H00OOC0WHQ b 4^ 1.21 2.13 1.21 1.41 1.08 1.84 2.14 1.66 2.06 Alkalinity. Oi 7.29 6.88 8.11 8.94 2.71 4.00 2.33 0.89 p 05 to 6.43 7.73 8.80 12.83 15.20 14.48 10.35 9.15 b co C5 O' 4^ 4^ Cn 05 Ci CO 4i- to to co b bi b b io i-' to C5 CH O O to CD CO to Sulphuric Acid. .123 .000 .024 .126 .010 .158 .300 .060 .310 O' oooooooo i; c c o oo O!XQW4-CCC; co o bobpooo'^o HNCOOOHOtHtO 4^4^©t04^COOOO Iron. 23,182 tO I-1 <-1 4^ 4^- cn o o H-*: on woo q o o o: o to ci O O O O • o cn o 12,493 9,000 4,550 12,000 2,800 2,600 51,450 5,050 63,828 5,300 27,475 7,850 14,000 4,300 175,500 268,500 7,700 Bacteria Per Cubic Centimeter. RESULTS OF ANALYSES. 273 Monongahela River-At Intake of Monongahela Water- Company. (Parts Per 100,000.) 864 902 790 807 844 J CH CO bO 4^ 4- CH 657 679 695 622 644 552 570 587 606 Serial Number. Av'gs, Apr. 4 " 18 Av'gs, Mar. 7 " 14 " 28 Av'gs, Feb. 7 " 14 " 21 " 28 Av'gs, " 17 " 24 " 31 s 00 • CD , 00 o co * Av'gs, 1897. Dec. 6 " 13 " 20 " 28 Date of Collection. 1 Slight Dec'd Slight V. t'd Slight Dec'd 4 c < c • Dec'd V.t'd Slight Slight Mud'y Dec'd Slight V.sl'gl Turbidity. to to to to o k I 02' 0o OS' .20 io io io io o o o o to 4-* to to to to to O O O Cn O .25 to to to Color. .0079 28 to co Q 00 .0080 .0040 ■.0052 !.O148 1 ZIW .0160 !.0080 .0166 .0062 .0095 .0082 .0064 .0084 .0180 .0064 .0166 .0320 .0140 .0076 .0128 Albuminoid Ammonia. Nitrogen as, .0018 .0020 .0016 .0025 .0028 .0026 ,.0020 .0021 8888 p- to to co oo qo to 0800' 88888 Cn to co to Q Ci Cc too .0030 .0016 .0066 .0020 .0020 Free Ammonia. 1 .0000 .0000 .0000 .0000 .0000 .0000 .0000 Jill I illii .0000 iiil Nitrites. b & o .0450 .0450 .0425 .0450 .0450 .0375 .1500 O MH o: to cn : ch CH o Cn to 44 Cn '.1425 .1350 .0825 .1050 .1575 .1275 .2250 .0750 .1050 1.1050 Nitrates. bo to o >- b b O Cn CD to 09'0 90'1 SZ'I I1-11 1.12 1.52 1.00 r O CO 4-1 0.79 0.70 1.14 |o.91 !] .02 kT 0.75 1.50 1.28 1.73 Chlorine. 12.7 co to to to 1 20.3 17.4 13.6 30.0 21.9 23.0 24.4 127.6 12.8 1 29.8 HCltO WH to 4* to to 00 bo b b b b 32.8 HHHO) tO 4x CO ~ I book Total. Residue on Evapora- tion. 2.5 4^0 bo to PPP 4 4b o p p p p 4* bo 4 bo 17.3 4^4-H C Q H o p to to (X to 44 20.3 P H W Ol 4 b b b Suspended. b co 4^ to bo pl 7.2 5.2 2.8 4^ ^7 6.6 4.8 5.6 2.0 p Cn ^OCnscn to 4 to to b 11.2 6.4 4.4 2.0 Loss on Ignition. 2.35 2.88 1.82 5.03 5.80 5.66 3.62 99'8 co to 4>- 4^ 4 b to to o 4^ co to 2.80 2.14 3.14 2.61 1.87 4.22 3.18 5.18 3.03 2.43 2.10 Total Hardness. CH 1.10 1.20 1.04 1.01 1.01 1.10 1.32 co b 4 O Cn O to 1.38 1.42 1.61 1.05 2.00 0.84 1.43 1.82 1.54 1.60 0.78 Alkalinity. 132 I-1 P b b oo 3.33 bob Ch Ch O 3.46 CO to ^7 O to cn to CO O Q to o o CO 4^ to 4-1 CO O tO CO ^7 O 00 CO O GO 1.83 to 4-1 to 4^ io w b os O4^DCC Sulphuric Acid. .019 b b to *-> 00 o .028 288 Q O 00 .129 1 '.020 .016 .380 .too .206 .170 .420 .038 to 4-* to to k ZSl- oor Iron. 8,850 9,000 8,700 11,033 to 5H5HJO ccxb 888 11,525 pnpojoj-* 4^ OL >- Cn O O Cn o O o o 21,980 44 888 5,700 37.250 7,125 11,500 2,750 Bacteria Per Cubic Centimeter. APPENDIX NO. 2. 274 Monongahela River-At Intake of Monongahela Water Company. (Parts Per 100,000.) Serial Number. Date of Collection. Turbidity. Color. Nitrogen as, Chlorine. Residue on Evapora- tion. Total Hardness. Alkalinity. Sulphuric Acid. Iron. ii n Bacteria Per 1 Cubic Centimeter. Albuminoid Ammonia. Free Ammonia. Nitrites. Nitrates. Total. Suspended. Loss on Ignition. I 1898. 942 May 2 Dec'd .20 I .0108.0016 1 II .0000.0225 0.80 14.0 4.0 4.0 2.10 1.75 1.13 .020 6,650 989 " 16 .35 .0140.0020.0000.0075 1.00 20.4 9.4 3.8 3.70 1.222.97.010 40,900 1048 " 31 Slight .30 ,0128|.0042 .0000.0525 1.84 1 II 15.8 6.5 2.7 3.35 1.422.89.008 1 1 25,200 Av'gs, .28 .0125 .0026 II ' .0000.0275 1.21 16.7 6.6 3.5 3.05 1.46 2.33 .013 24,200 1082 June 13 Dec'd .30 .0122 .0120 .0000.0225 1.75 15.8 1.0 3.4 2.84 0.74 6.44.002 8,550 1133 " 27 0.17 .12 .0088 .0072.0000.0525 1.10 15.2 2.4 4.0 3.70 1.50 4.05.006 1 22,700 Av'gs, .21 .0105 1 .0096.0000 .03751.42 15.5 1.7 3.7 3.27 112 | 5.24|.OO4 15,600 1184iJuly 11 Slight .20 .0142 .0022.0000 .0675 1.65 19.4 5.0 3.4 5.71 1 1 1.745.26.006 1234 " 25 ■ .25 .0110 .0060.0000 .0975 1.20 14.7 2.7 3.9 • 3.58 0.82 3.13 .006 25,300 Av'gs, .22 I 1 .0126.0041.0000.0825 1.42 17.0 3.8 3.6 4.64 1.284.19 .006 25,300 1307 Aug. 11 0.57 .30, .0190.0050.0000.0375 111 0.52 29.2 21.6 2.0 1.95 1.62 1 1.38.006 1 34,300 Mineral Analysis. Sample Collected September 20, 1898. (Parts Per 100,000.) Total Solids 21.80 Loss on Ignition 6.00 Calcium Oxide, (CaO) 3.32 Magnesium Oxide, (MgO) 0.77 Sulphuric Acid, (SO3) 9.81 Chlorine, (Cl) . 1.04 Silica, (SiO2) 0.47 Iron Oxide, (Fe2O3) 0.00 RESULTS OF ANALYSES. 275 SOUTH SIDE TAP. Samples of the "Tap Water" upon the South Side were collected, whenever a river sample was obtained, until September i, 1898. dhe water is pumped direct from the river to a reservoir upon the hill about one-third of a mile away, of 5,000,000 gallons capacity. The reservoir consists of two basins, one of which is used for settling, and, from the other, the water is distributed over that portion of the city, south of the Monongahela River. The samples were collected from a store upon Carson Street, near 30th Street. South Side Tap. (Parts Per 100,000.) 77 no 121 135 143 160 168 59 Lf 88 58 W 4-> l-i 0500500 Serial Number. Av'gs, Aug. 2 " 12 " 16 " 20 " 23 " 26 " 30 Av'gs, July 6 " 12 " 20 " 26 J Av'gs, | 1897. June 10 11 17 " 21 " 30 Date of Collection. x CD * ~ o_ os q2 p p7 p7 Dec'd Mud ' y (( Mud'y Dec'd Turbiditj o Color. .0173 .0170 .0204 .0140 .0174 .0206 .0170 .0144 .0188 .0180 .0130 1.0214 .0230 ozw .0120 .0100 .0340 .0120 Albuminoid Ammonia. .0082 .0023' .0045 .0020 .0046 .0120 .0115 .0207 .0059 8288 4- 0 ® w OPtiC C?< tc 0130 .0000 .0030 .0050 Free Ammonia. X 0 .1 8 8 o s 8 8 8 8888888 | .0000 i.0002 .0002 .0001 i .0000 .0000 1 Nitrites. 0 PS z H- co .1075 .0925 .0605 .1050 .1500 .1500 .1275 .0789, 0 0 0 - oo CC' 01 cn 0 O O .0740 1 onr, 0280' Nitrates. 1.03 1 3.25 0.60 0.45 0.62 0.64 1.02 0.60 0.54 0.40 0.65 0.66 0.45 65 I 1 p w p p P CH W CO 0 0 o< 0 Chlorine. 14.9 1 1.3 13.0 14.6 13.2 13.0 20.6 18.4 16.0 12.0 10.4 19.9 21.6 bo 19.2 12.0 52.4 15.6 Total. I Re Et 3 2' 2.J 3.4 6.6 2.2 1.0 7.2 0.2 CR LC 1'6 VL 9'1 8'5 1 11.0 38.8 5.2 Suspended. 0^8 2 0 p 4- 3.8! 4.6 3'2 5.6 4.4 6.4 CO 0 4.8 3.2 3.6 4.1 CO 5.0 5.6 10.4 3.3 Loss on Ignition. 6.12 4.10 4.52 7.71 6.10 6.60 6.50 7.30 H'S 5.10 3.40 5.31 6.75 ^1 to 10.20 j 8.40 6.50 4.00 Total Hardness. IC 1 3.01 2.25 2.55 2.72 2.03 2.53 0.80 4^ 0 w CO Cn 4- 888 = Alkalinity. ?c I 2 1.49 1.30 2.03 2.75 3.44 4.01 6.29 2.33 LVZ 69'5 29'5 89'1 3.73 5.64 3.30 2.80 3.20 Sulphuric Acid. .210 .260 .200 .220 .260 .100 .420 .010 r 8 • • Iron. 2,633 2,300 3,650 1,950 880 ••• 088 Bacteria Per Cubic Centimeter. APPENDIX NO. 2. 276 South Side Tap. ( Parts Per 100,000.) 553 571 588 607 427 449 459 479 487 500 507 537 311 332 338 361 368 388 397 420 186 202 227 246 252 278 284 302 Serial Number. Av'gs, Dec. 6 " 13 Dec'd " 20 Slight " 28 Av'gs, Nov. 1 Slight " 3 " " 8 " 10 Slight " 15 " 17 Dec'd " 22 " 29 Dec'd Av'gs, Oct. 4 Slight " 6 " " lllV.sl'gt " 13 Slight " 18 " " 20:i " 25V.sl'gt " 27 Slight Av'gs, 1 GO .............. (th-* - ~ ~ CO to to K) K) 4-< >-< <1 05 S'S- S- Date of Collection. Turbidity. to =*S= co E LO to .40 .0240.0018.0000 .20 .0116.0036.0000 .20.0080.0016.0000 .20.0116.0018.0000 II 1 .19.0158.0130.0000 II 1 1 .10.0146.0240.0000 .15 .0248.0220.0000 .20 .0148.0210.0000 .20.0148.0234.0000 .20 .0140.0052.0000 .20.0128.0026.0000 .20 .0120.0040.0000 .30 .0188.0018.0000 .12.0378.0098.0000 1 1 .20 .0228.0160 .0000 .20 .0220.0160 .0000 .10 .0410.0042.0000 .15 .1180.0026.0000 .10 .0240.0160.0000 .10 .0128.0180.0000 .05 .0240.0030.0000 .10.0380.0030.0000 .26 .0129'.0105.0000 1 1 .40 .0120 .0092.0000 .45 .0115 .0104.0000 .30 .0140.0092.0000 .20 .0142.0092.0000 .05 .0134.0092 .0000 .15 .0136.0150.0000 .30 .0108.0092.0000 .25 .0136.0130.0000 Color. Albuminoid Ammonia. Free Ammonia. Nitrites. Nitrogen as, .1444 .2100 .1575 .0975 .1125 ,.0750 .0975 .1575 .0225 .0225 .0750 .0900 .0750 .1297 .0825 .0975 .1313 .1500 .2160 .1575 1.0975 .1050 1 .1064 .0825 .1312 .1500 .1050 .0525 .1575 .0975 .0750 Nitrates. |i 1 1.07 28.244.8 0.80 51.6 39.2 1.26 22.810.4 1.22 21.2: 8.4 1.01 17.2 1.2 1 1.30 23.5, 5.4 1.3818.4 1.0 2.13 24.8 2.0 1.54 24.4 0.1 1.42 22.8 0.2 0.9016.0 5.2 1.11 26.4 8.4 0.8413.2 0.5 1.09 42.025.8 1.36 26.9 ... 1.1123.2 ... 1.34 22.0 ... 1.29 24.4 ... 1.52 33.6 ... 1.40 30.8 ... 1.21 29.2 ... 1.32 24.4 ... 1.69 27.6 ... II 1 0.9515.6 ... 0.91 14.4 0.4 0.4413.2' ... 0.9313.6 ... 1.0516.4 ... 1.01 15.6 ... 1.0515.6! ... 0.94 17.2: ... 1.2718.8 ... Chlorine Total. Suspended. Residue on Evapora- ri TION. g 5.9 3.09 Oi 0 0 H-1 W to 4^ CO IO 4- co to co to 6.6; 6.24 5.2 7.21 8.8 6.97 7.2 6.41 7.2 6.53 6.0 5.80 8.4 6.24 4.4 5.94 6.0 4.82 7.0 6.19 bo 00 4^ 4^ 4- 4. 4^- 05 C5 . . C5 C5 <35 Cn i->i-1: : cbib 4- - I tC O 4- O 4.4,1 6.11 3.6 5.55 4.8 5.37 2.0 6.93 4.4 7.54 4.4 6.39 5.2 5.32 5.6 6.30 5.6 5.51 Loss on Ignition. Total Hardt | 18 W QQ' I 1 1 1.71 2.33 1.392.30 2.251.89 0.843.40 1.325.49 0.997.84 1.147.46 0.887.94 1.248.97 1.603.09 1.143.85 1.672.44 1.922.37 I 0.6410.78 W Cn 4* 4^ 4- 05 J-* to Cn O IO O O' K 05 H 4 4 4 ", 5 O » » CO O ui O 0 O tO CO 01 w h b 4^ Cn 1.894.80 1 I 1.384.43 2.211.54 1.726.29 1.584.78 1.894.98 1.934.50 2.255.40 2.186.46 Alkalinity. Sulphuric Acid. .236 .430 .204 .130 .180: .125 co 0 0 0 0 0 to 0 to CH H-J co to to O00OC5OOO to 8 0 .014 .006 .004 .001 .001 .006 .006 .008 gw .050 .124 .052 .036 .004 .024 .026 .020 Iron. 9,883 20,650 8,450 550 9,650 8,500 13,550 9,650 8,000 5,700 8,500 13,650 1,921 1,500 2,650 350 100 125 1,025 7,700 cn 5,800 1,200 6,050 22,575 1,350 1,300 1,475 6 300 Bacteria Per Cubic Centimeter. RESULTS OF ANALYSES. 277 SoutK Side Tap. (Parts Per 100,000.) 1083 1134 O CD to oo w 865 903 791 808 845 716 735 755 773 623 645 658 680 696 Serial Number. Av'gs, June 13 " 27 Av'gs, May 2 " 16 " 31 Av'gs, April 4 " 18 Av'gs, Mar. 7 " 14 " 28 Av'gs, 83 > > 13 „ fl „ Z qaj Av'gs, 1898. Jan. 3 | " 10 ■" M | ■ 31 Date of Collection. Dec'd u Dec'd cc Slight Dec'd V. t'd Slight <c V. t'd Slight Dec'd u ii Slight Dec'd V. t'd Slight Turbidity. .26 .32 .20 CO o co co to omen .22 to to Cl o .20 to 'to to o o o to .20 .25 .20 .20 .23 to to co to to O O O Ci o Color. .0089 .0110 .0068 .0110 822 o CO o 4-00 .0106 .0064 .0148 .0080 .0034 .0044 .0162 co GO .0132 .0084 .0268 .0068 .0096 82888 GX CD ~4 GO to to o to ex Albuminoid Ammonia. .0053 .0038 .0068 .0023 888 WHH CO CO 4- .0017 .0018 .0016 .0021 .0024 .0022 .0016 .0021 .0028 .0020 .0020 .0016 8 CD 88888 LC M H O GO 00 4- CX Free Ammonia. NITROGEN AS .0000 .0000 .0000 i .0000 .0000 .0000 0000' .0000 .0000 I .0000 .0000 .0000 .0000 .0000 .0000 .0000 .0000 i 88888 88888 Nitrites. .0412 .0300 .0525 8 8 b b b CnOH to Cn Oi O1 o .0412 1 .0450 .0375 00S0- o o o 4- Cl Cl Cl tO LO o Cl Cl .1675 O NH CD ; - o. otc O O O' to ci S to to 5 co O Cl Ci Ci Ci o o Nitrates. 10'I 5. o 0.83 0.82 0.76 0.90 18'0 0.90 0.72 0.85 0.78 0.84 0.94 1.04 0.82 1.10 0.72 1.51 0.86 SZ'O 39'0 00'I 86'0 66'0 Chlorine. 17.0 17.3 16.8 14.4 17.0 15.2 10.9 22.5 12.7 32.4 20.7 15.8 13.9 32.4 37.7 H C W K) CHOO to b o b l'3f CX CO Ci CO ex qo -q 4^ c< b b ex b b Total. to 1.2 3.6 5.1 w b b 12.1 LC 4^- O b to po to b b b 24.8 1.8 9.6 80.4 7.6 co p 24.2 39.2 26.6 54.8 5.2 Suspended. >IDUE ON APORA- noN. U-i 4.4 3.8 3.2 to to 4- b b 4^ 4.8 5.2 2.4 4^ 6.0 4.8 3.2 5.5 64 4.4 8.4 2.8 7.8 Wcooooot b to b b b Loss on Ignition. 3.57 Ji- to to b CD O' 3.04 2.18 3.45 3.48 2.45 2.92 1.98 4.73 4.49 5.89 3.80 3.50 tO to 4^ 4^ GO Ci to *00 CX 00 o ex 3.02 K>C0C0 4^l-' b b b i- b o oo o to 00 Total Hardness. 1.12 0.60 1.65 zrt 1.76 2.01 1.53 1.50 1.40 1.60 io 4- O b b b o o co 1.33 b -m -i b oewte 1.49 0 4-4-4-4- b b b b b 0 4-MCO3 Alkalinity. 4.97 4- ?' b b 4- O tO to Ci to to >-* b to b O> 4- O' 1.95 2.68 1.23 tO CO 4^ 0^4^ O 00 4^ 3.46 to to o bo to bo CX Cl to bi co to tO to to co Ci ci o CO CO 4- H Sulphuric Acid. .004 88 00 I-* .017 .025 .015 .010 .031 .016 .046 .029 b b b MHO o to o .152 .248 .280 .980 .300 .387 .460 .510 .330 .400 .235 Iron. 7,550 950 14,200 10,200 1,500 27,000 2,100 5,875 2,300 9,450 4,283 350 2,400 10,100 9,100 450 8,250 21,600 6,100 17,480 2,550 29,050 16,200 37,100 2,500 Bacteria Per Cubic Centimeter. APPENDIX NO. 2. 278 South Side Tap. (Parts Per 100,000.) co CO to - CO 00 CH O< Serial Number. Aug. 11 «T crcf to QI - co o co Date of Collection. Dec'd -o5' jr Turbidity. 05 O io 8 8 Color. o 05 CO o 82 CO co CO o Albuminoid Ammonia. 2 5 o o to 1 88 CO 4- Free Ammonia. § § IB Nitrites. M % o o o o b g b CO o to o 5o o IO O cn Nitrates. p b co 05 On 8 8 Chlorine. to 00 bo o b CO o b b Total. IO b to b b 4- Suspended. 5 3 g o a to co b to Loss on Ignition. > o IO +- Total Hardness. O bi b o b t Alkalinity. 00 CH co 4- Ci bi bo or. Sulphuric Acid. 8 Co 8 s s co o Iron. - - 15,000 Io: cn : Bacteria Per Cubic Centimeter. ALLEGHENY RIVER AT MONTROSE. Samples were collected from the "Allegheny River," at the Montrose Pumping Station of the Allegheny City Water Works, four miles above Brilliant, about once a week during the months of June, July and August, 1897. After this time, until December, 1897, the river at Hulton (see page 285) was taken as fairly representative of the river at Montrose. It was then found that the analyses of these river samples differed but very little from those collected at Brilliant and, throughout the remainder of the work, the samples collected at the latter place were taken as fairly repre- senting the conditions at Montrose, Hulton and Wildwood. A portion of the water supply for the city of Allegheny has been obtained from the river at Montrose since April, 1897. At first about one-third of the water used was pumped from here and the remainder from the city pumping station near Herr's Island. At the close of our work, almost all of the water was pumped from Montrose, being about 30,000,000 gallons per day; occasionally, however, about 5,000,000 was pumped from the lower station. The water is obtained from a crib in the river, which is connected by four 36-inch pipes with the pump well. This crib is about 2,500 feet long, 32 feet wide, and 7 feet deep, and was built of 6-inch x 8-inch hemlock timber, laid flat. The timbers are separated by blocks, four inches thick, spaced about three feet apart. The crib is tightly planked over on top with three-inch planks, but the sides, ends, and bottom are open. In. placing the crib, an excavation, somewhat larger than the area of the structure, was made and the crib floated over and sunk into place RESULTS OF ANALYSES, 279 by loading with large stones. Stones were then placed around the sides and upon the top; and covered with layers of coarse gravel, with sand upon top. The average depth of gravel and sand on the crib is five feet. The depth of water over the crib at low water is 16 feet at the upper end and 10 feet at the lower end. The center line of the crib is 300 feet from the river wall of the pumping station. Upon two occasions it was thought that some of the sand and gravel had been washed away and a considerable amount of new material was dumped in place. The sam- ples were collected over the crib from the ferry boat which crosses the river between Montrose and Verona. Allegheny River at Montrose. (Parts Per 100,000.) 218 266 96 118 146 179 39 48 67 f-s 21 Serial Number. Av'gs, cn IO *4 Av'gs, Aug. 9 " 16 " 23 " 30 Av'gs, July 12 " 20 " 28 Av'gs, 1897. June 15 " 28 Date of Collection. Slight V.sig't Slight V. t'd Slight Dec'd Mud' y i I Turbidity. to .25 .30 Cl cl: : : Color. .0131 .0140 .0122 s bO .0197 .0340 .0190 .0190 S 4- 2 H-1 tO 0 0)0 .0170 .0160 .0180 Albuminoid Ammonia. .0019 .0024 .0014 8 CO 8888 CO O O .0020 .0002 .0025 .0034 0000' .0000 .0000 Free Ammonia. 2 W o .0000 10000' 0000' i .0000 .0000 .0000 .0000 .0001 .0002 .0001 .0000 .0000 .0000 Nitrites. Q W o Cl 05 .0600 .0712 1680' .0888 .0750 .0750 .1200 .0452 .0034 .0285 .1036 10890' I 0890' Nitrates. 00 Cl CO 2.09 1.08 tO bO 1.20 4.70 1.24 1.86 k-I Cl © IO co CO i-' -Cd 05 ci 1.50 1.80 Chlorine. - 11.2 15.6 to 10.0 20.0 8.2 11.2 tO p to 12.4 42.7 32.5 9.8 11.6 Total. 0.6 : 3.2 0.6 0.2 ■-I Ci tO IO co oo p Suspended. 5^3 o 3 O< co 0'9 ZD 4.1 7.0 3.4 5.2 bO 6.0 7.6 4.9 Cl to 4.8 5.6 Loss on Ignition. ► o ' % pt Ci 5.26 5.81 1 99'9 5.50 10.00 5.19 5.50 05 4.35 5.22 4.50 Cl 10.20 4.80 Total Hardness. Ci co 5.15 5.52 o Ci 6.19 4.28 3.78 4.36 OS o w p CO GO cc 8 8 Alkalinity. to Ci 0.86 1.64 s Ol X H H W 1.38 1.40 i.U to MM 66'0 Sulphuric Acid. .035 .026 .044 p .065 .100 .120 .080 to to 4- tO O tO 4- O o o to i 8: o • Iron. 8,650 15,050 2,250 2,631 700 2,225 3,050 4,550 co - * I Bacteria Per Cubic Centimeter. 280 APPENDIX NO. 2. EFFLUENT-MONTROSE CRIB. Samples of the water which had passed through this crib into the pump well were collected once a week, from the beginning to December i, 1897; after which they were collected once in two weeks. These samples were collected from the lower floor in the pumping station, by lowering the bottle into the pump well. Effluent-Montrose Crib. (Parts Per 100,000.) tO LC tC LC CO OS co o GO 00 O Qi 78 97 119 147 180 40 49 68 to Cl co Serial Number. Av'gs, Sept. 7 " 14 " 22 " 28 Av'gs, Aug. 2 " 9 " 16 " 23 " 30 Av'gs, July 12 " 20 11 28 Av'gs, 1897. June 15 " 28 Date of Collection. Slight c * It V.sl'gt Dec'd Slight Dec'd Slight It Slight Mud'y Turbidity. OS to bo CO CO ci o o c< o o • • • • Color. .0150 .0176 .0124 .0180 .0120 tc o co 2 2 2 S S <1 O <1 Cl W Cl Ci 4^ O O b co co .0201 .0392 .0315 .0145 b b 00 o o Albuminoid Ammonia. 8 IC 8888 CO CO 4- 4- GO IO 8 to b b b b b o o o o o 1- to ct to to 00 O O -A o .0041 .0048 .0030 ,.0046 .0000 .0000 .0000 Free Ammonia. SlTRO I |0000' 0000' oooo' 0000' 1 i iiiii 1000' .0003 .0001 .0000 i .0000 Nitrites. K 2! ► .0675 .0375 .0300 .0825 .0686 .1112 .0666 .0375 .0525 .0750 .0528 .0015 .0405 ,.1165 1 .0550 .0550 Nitrates. § H-i tC tC to CO Cl OO On CO bl CO CT b- to CT O O O to 1.49 I-1 to bwb to -i 1.55 b ct Chlorine. i-1 co 12.0 13.2 15.2 13.2 10.5 11.1 10.2 11.2 9.6 10.2 LC bi 12.4 34.9 26.2 12.4 13.6 11.2 Total. 0.6 1.4 1.2 0.4 co b 9'91 777 ro Suspended. 3IDUE ON ,7 APORA- TION. 4.8 Q^CT*- b o to b 4.0 O'S DS S'f 7^ r 6.0 "I OS bo to b C5 b b to Loss on Ignition. Ci Ci b bo bo bo co o oo 5.80 CT CT I CT 4- br CT bo CT CO O co O 41- CO 5.93 5.03 4.45 7.50 10.40 4.70 Total Hardness. ors 5.01 5.90 5.92 3.56 CO o 5.15 6.64 4.50 3.82 4.37 6.29 6S'J 00'8 Alkalinity. 1.88 1.41 1.51 1.72 2.88 111 0.87 1.31 1.17 0.92 1.27 *-A 1.42 1.24 11.41 1 32 ct b CT CO Sulphuric Acid. IW oooo 35 CT to W to to o o Lr CT CO 8 O O O O O .229 .008 .280 .400 § .000 Iron. 6,544 17,500 1,675 2,425 4,575 6,160 2,400 725 15,050 2,575 10,050 'to 8 9,200 Bacteria Per Cubic Centimeter. RESULTS OF ANALYSES. 281 Effluent-Montrose Erib. (Parts Per 100,000.) Av'gs, I 784Mar. 1 823> " 15 856 " 29 749 Feb. 16 ii, | Av'gs, 1898. 629 Jan. 4 671 " 18 । Av'gs, ' 1 561 Dec. 7 600! " 21 's3(Ay 437 Nov. 2 473 " 9 494 " 16 524 " 23 Av'gs, t Seii 00 O CO 00 o " " ~ 5* SC ba i-i hi r4 Ci c© ba Cn Serial Number. Date of Collection. V.sl'gt Slight Slight V.sl'gt Slight Slight I c Slight V.sl'gt (I c C - Turbidity. to .25 .25 .25 CO pl C'O o .30 .30 CO o I .30 .30 co 4- 4- io h* O O Ox Cn to io ba io 44 OOOxO Color. I Ci .0072 .0048 .0108 8S00- .0090 .0084 .0096 .0096 .0084 .0135 .0060 .0120 .0240 .0122 to 00 o 2 2 2 OH4-O> O O 05 Albuminoid Ammonia. Nitrogen as, I 888 IO io co O IO o 8 IC oo .0045 .0040 .0050 8 .0016 .0018 |0200' 8888 co i c W to Q O Fl00' 1.0018 1.0018 1.0010 1.0012 Free Ammonia. .0000 .0000 .0000 .0000 .0000 .0000 .0000 .0000 i .0000 .0000 .0000 lilt 1 §g§§ Nitrites. .0500 II II 1 .0525 16.92 49.6 0.2 5.2 .0450 38.90 95.2 0.420.0 .0525 21.42 55.6 0.810.6 ggir .0637 .0525 .0750 CO CH .0900 .1050 .0731 '.0450 '0450 .0675 .1350 £S90' 1.0750 1.0825 1.0600 1.0375 Nitrates. II J J , 25.75 66.8 0.511.9 II 1 1 Q'018'0 Wore 11.94 54.0 0.216.0 6.47 40.0 0.012.8 17.4168.0 0.419.2 4.67 23.0 2.8 9.0 2.9017.2 5.2 6.4 6.44 28.8 0.411.6 3.30 18.9 2.1 7.1 4.40 20.0 0.2 7.6 4.05 17.6 0.6 5.6 2.86 25.2 7.6 9.6 1.88 12.8 0.0 5.8 3.0017.1 ... 6.6 3.25 16.8 3.04 16.0 2.84 16.4 2.88 19.2 Chlorine Total. Residue on Evapora- tion. O O O <1 4- 4^ 4- tO Suspended. Loss on Ignition. p bi cn 4.22 7.32 5.12 4.22 7.84 p p o o 2.95 3.22 2.68 19'1 1 5.39 5.38 4.72 2.96 5.22 Ox Ox Ox 44 44 io io J© OO> WM Total Hardness. o 2_ 1 3.321.15 4.950.82 4.041.06 | 3.180.96 3.531.37 4.431.82 2.640.92 | to c Jo ba 2.360.86 2.130.99 | | 20'6 883 1 1 ba 4- Ox pt OS 44 44 co ox ci ba o r- H-4 JO 4- o bi CO 4- O' - I | 4.902.30 O' C3 4- 4- to O bl IC c 0 to ba 44 ba 44 ox 00 w © 00 Ox '1 Alkalinity. Sulphuric Acid. . II £96 £ W .028 8,350 .030 7,650 .022-' 7,900 .086 13,900 .066 30,400 .052 44,800 .080 16,000 .155 27,000 .232 27,000 .078 .106 29,250 ■ .048 66,500 .098 17,900 .180 19,500 .100 13,100 .046 97,262 .058 3,050 .036 42,000 .042 173,000 .048 171,000 Iron. Bacteria Per Cubic Centimeter. APPENDIX NO. 2. 282 Effluent-Montrose Crib. (Parts Per 100,000.) co to to O GO 1176 1224 1077 1126 982 1033 896 934 Serial Number. Av'gs, Aug. 2 " 16 Av'gs, July 6 " 19 Av'gs, June 7 " 21 Av'gs, 15 „ 01 Av'gs, 1898. Apr. 12 " 26 Date of Collection. Slight c c V.sl'gt Slight Dec'd Slight Slight Turbidity, tg .27 .30 to io io CR ^1 io O .27 .32 w co to CR w .25 .22 Color. .0111 .0074 .0148 8 5 - 00 o to 07 .0072 .0180 .0099 .0088 1.0110 .0070 .0062 .0078 Albuminoid Ammonia. Nitrogen as, .0025 .0030 .0020 .0017 .0018 .0016 .0026 .0042 .0010 .0042 .0052 .0032 I .0024.0000.0675 1 88 to g Free Ammonia. .0000.0562 .0000 .0000 .0000 .0000 .0000 .0000 0000' 0000' .0000.0300 .0000 .0000 0000' 0000' Nitrites. OR 07 IO Q O' Q CR .1200 .0750 IO LO CR .0225 .0225 .0150 .0450 .0750 <0600 Nitrates. 5.28 3.08 IJT to to g j Y j 5.15 5.30 5.00 pout sroi 38'11 12.05 8.80 15.30 Chlorine. 22.8 31.0 14.6 bi 9.8 13.2 I29'1 'j. b< bi 40.4 38.6 03 07 O0 CR LO to p co co Total. Residue on Evapora- tion. 5.0 co io 0.2 0.2 0.2 roi 0.7 19.6 0.3 ' 0.2 0.4 0.6 CO 4- Suspended. 07 4- 3.9 8'8 0T p 6.0 6.8 9.8 CO o to 4- 0'8 4.0 12.0 Loss on Ignition. 6.49 CR 07 03 o & 4- 3.40 6.21 CR io 5.88 4.66 bs'oi 9.90 10.70 4.14 3.80 4.48 Total Hardness. o r-1 03 CR bi O LO 07 3.36 4.00 03 § 1 9£'£ 6SS 4.15 4.20 4.10 3.73 3.35 4.12 • Alkalinity. H-1 1.54 1.38 1.30 0.55 2.06 1.00 1.00 28'0 1.13 0.61 0.69 1.05 0.34 Sulphuric Acid. - .016 .010 .019 .024 .014 ,014| .002 .026 s 1 .028 .012 .039 .046 .032 Iron. 21,000 20,100 22,000 10.300 28,300 19,300 43,000 69,300 16,700 7,600 4,400 10,800 1 1 7,850 4,050 11,650 Bacteria Per Cubic Centimeter. ALLEGHENY CITY TAP. Samples were collected of the "Tap Water'' in the city of Allegheny once a week from the beginning of the work until December I, 1897, and then once in two weeks for the remaining time. The water from Montrose is pumped to a reservoir in the city, of 7,000,000 gallons capacity, and there mingles with the water pumped from the £ity station. From this reservoir the water is distributed over RESULTS of analyses. 283 the city, but a change is now being made so that water from Montrose may be distributed direct to the city without going to the reservoir. These samples were collected in a store upon Federal Street, near the railroad station. Allegheny City Tap. (Parts Per 100,000.) 309 342 366 395 217 230 260 282 79 132 178 O O Ci K> Serial Number. Av'gs, o S 4- Av'gs, i Sept. 7 " 13 " 21 27 <kT CD Aug. 2 " 20 " 31 Av'gs, July 13 " 20 " 28 1897. June 30 Date of Collection. Slight V.sl'gt V. " !V. " Slight I c <I Slight Dec'd Dec'd Mud'y ll Turbidity. to .40 .30 .40 .20 .35 bo to 4- O< CD O O - O' • Color. b .0152 .0148 .0143 .0120 .0128 b b b b O 4- Cl t© IO O 00 .0187 .0180 .0196 .0184 6850' .0145 .0372 .0350 .0140 Albuminoid Ammonia. Nitrogen as. .0023 8888 CO IO IO o XXOOO .0015 8888 io to CO CO .0020 8500' 8100' S100' .0015 .0013 .0018 .0013 0000', Free Ammonia. .0000.0787 .0000.0675 .0000.1350 .0000.0675 .0000.0450 .0000 iiii 1 .0000 .0000 .0000 .0001 .0002' .0001 .0000 i Nitrites. .0412 .0450 .0375 1.0450 .0375 .0894 .1408, .0600 .0675 .0540 .0030 4.35 .0360 1.55 .1230 0.95 GC O Nitrates. i O co co co to bo Ci co bo 00 IO Ci IO Ci oo 1.90 2.49 3.22 3.12 i- GO to io HOCO 2.2S 08'1 Chlorine. 17.5 17.2 15.2 18.8 18.8 15.1 11.6 14.0 17.6 17.2 CO be 12.2 10*8 16.8 * 15.6 42.5 25.6 Total. Residue on Evapora- tion. 3.8 CD to co Ci co 14.6 to OiCDC o to Suspended. Ci o 7.2 5.2 6.4 7.6 pl bo 2.8 5.0 7.6 6.0 3.8 4.8 5.6 6.0 4- -4 C". to b bo Ci Loss on Ignition. 5.33 5.60 5.01 5.10 5.60 6.44 pi I - i pi 4- U o io Ci CH d to pl co to 4.36 5.75 5.84 4.81 4.25 5.15 5.03 6.00 Total Hardness. 5.07 5.34 ! 4.74 4.90 5.30 5.26 4.89 5.76 5.51 4.89 co 5.10 3.90 4.58 7.14 I 8.50 7.50 5.43 Alkalinity. oo to to to co Ci CO O 4- IO Ci CD to OS'S 89'1 6Z'O rl 0.74 bo to Ci 4- IO 1.51 1.75 1.74 1.03 1.87 Sulphuric Acid. .063 b b b b W Cl M © Cl K O .045 .044 .044 .056 .036 CD .155 .160 .270 .209 .006 .360 .260 .000 Iron. 88,512 13,400 51,150 135,1X10 154,500 7,311 8,170 12,700 1,900 6,475 1,737 1,050 2,425 5,340 ! 2,880 , 7,800 Bacteria Per Cubic Centimeter. 284 APPENDIX NO. 2. Allegheny City Tap. (Parts Per 100,000. 884 931 CO 4- Co Cl O 714 753 8Z9 919 569 605 425 457 485 505 535 Serial Number. Av'gs, I Apr.ll " 26 Av'gs, - g to * GC Av'gs, Feb. 7 " 21 Av'gs, 1898. Jan. 10 " 24 Av'gs, Dec. 13 ' " 28 1 Av'gs, j 1897. Nov. 1 ; " 8 , " 15 " 22 " 29 Date of Collection. Slight Dec'd Slight V. t'd | Slight Slight V. t'd Slight 6 * Slight Dec'd u Turbidity. II .23 .0079 II .22 .25 .25 .0163 .25 .25 to CO .25 .22 |1 .27.0082 1 .30 .25 bo O .::o .30 bo 4- .20 .30 .40 .40 .40 Color. .0084 .0074 .0042 .0284 .0134 b b 4- to o co o o - o O Ct CO Cl .0130 .0120 .0140 oo oo .0120 .0110 .0220 .0148 .0340 Albuminoid Ammonia. Nitrogen as, .0018 .0018 .0018 .0022 .0014 .0030 .0031 .0040 .0022 8 to .0020 .0022 .0026 .0034 .0018 .0027 b b b b b o o o o o ^OOOCQO Free Ammonia. .0000 S8 88 I 0000' .0000 .0000 0000' b b 88 i .0000 .0000 I 0000' 0000' .0000 b b b b b §§§§§ Nitrites. .0412 .0600 .0225 .0450 .0525 .0375 0021' .1500 .0787 .1275 .0300 1.1425 .0825 .0600 b b b b b 00 05^0 4^ tO Cn O O< cn cn o o o Nitrates. Ih 5.42 7.13 | 3.S7 4.22 GO lb GO -I IL tO 6.03 CO co J bo to 4- 4.16 3.02 5.31 2.96 3.70 3.85 2.69 1.50 3.06 Chlorine. p co 19.8 24.8 b CT o co b b 35.2 34.0 36.4 CT b pn 4^ bo b 23.4 18.4 28.4 31.3 to to to p pi pt 4- -* 4- to b to to Total. Residue on Evapora- tion. co 0.2 0.4 19.6 0.4 38.8 b 0.4 2.4 20.3 15.6 25.0 bi 0.4 0.6 12.6 On to to p M p 4- b 4^ GO bn Suspended. . co 7.2 8.4 4- to 05 bo b co co co b O 19.8 to >- co o co a> 11.2 4- 00 O 4^ 9.7 11.2 9.6 8.8 3.6 15.2 Loss on Ignition. co CH 3.28 4.22 3.72 4.17 3.28 co bo 4- CO LO 4- C5 GO 3.22 co co to to O 4- 4.55 1 pl co b bn o o .*• cc 5.70 5.28 4.90 3.90 4.13 Total Hardness. 3.41 2.85 3.98 to co to w - co Cl o co 3.13 3.22 2.91 2.92 2.91 2.82 to co b- ' 4.30 5.45 4.99 1 4.46 3.20 3.39 Alkalinity. 0.97 1.24 0.71 1.38 0.96 1.52 1.30 1.75 1.23 bo b 05 1.42 1.20 1.65 to 05 2.51 3.88 2.47 1.16 1.27 Sulphuric Acid. .045 .046 .045 .045 .028 .062 .146 £ co »o o .290 co to to 05 o o J-A o On .088 .122 .202 .078 .086 .200 .136 .510 1 Iron. 4,475 3,250 5,700 11,200 15,550 6,850 3,925 4,300 3,550 22,950 18,700 27,200 10,325 12,600 1 8,050 57,326 CO 4-5 2-* ® oo bwcwo ct oo g g g Bacteria Per Cubic Centimeter. RESULTS OF ANALYSES. 285 Allegheny City Tap. (Parts Per 100,000.) U-l I-I -i H-1 __4 -* 1 1 oo to On o o § o Serial Number. Ow1 c: O GO IC Cp "'I Av'gs, Aug. 1 " 15 Av'gs, Julv 5 ""18 Av'gs, June 5 " 20 Av'gs, 1898. May 9 " 23 Date of Collection. Slight 4 4 Slight 4 4 Slight Dec'd Dec'd Mud'y Turbidity. to .25 .30 OS' .30 .30 CO to CO 00 CH O £ .30 .60 Color. o .01 .01 8 .01 .00 o 28 b to b b CO -' Albuminoid s 8S O -I IO to o GO OS to O' to o 80 180 Ammonia. Nitrogen j 8 ^1 .0018 .0016 .0021 .0024 .0018 8 Cn .0020 .0010 .0012 .0016 .0008 Free Ammonia. 1 .0000 .0000 § .0001 .000( 1 .0001 ,000( I .0000 .0000 Nitrites. b o to .0600 .0525 .0600 .0675 .0525 .0225 .0225 .0225 .0225 .0150 .0300 Nitrates. 4.02 tO <01 -i io GO O 4.41 CH 03 03 O 4^ to 3.52 4.97 p b o 1 5.96 7.22 Chlorine. !o 30 15 5 S GO b 12 65 CH CO 35 81 Total. b o to CO C to O GO co O OS 1 CD 11.0 4.8 b 2.9 0.2 to 1.2 45.2 36.9 18.0 55.8 Suspended. 3IDUE APOR TION. 4^ b 5.8 .3.4 co Oi 4- to Cn bo 3.8 7.8 bo CO 03 O <33 Loss on Ignition. T o 5.40 6.80 4.00 5.97 4.84 7.10 ore 5.20 5.00 b 7.92 7.10 Total Hardness. 3.96 5.03 2.90 3.71 4- CO CO o to 3.55 3.40 3.70 3.41 3.35 3.48 Alkalinity. io 00 1.41 1.16 0.95 0.22 1.68 0.91 0.75 1.07 o b to 0.96 0.89 Sulphuric Acid. GO o o w to o c» .028 .026 .030 .019 o o co o O CD .101 .152 .051 Iron. 13,500 20,600 6,500 6,800 1,000 12,600 1,950 1,950 8,400 10,000 6,850 Bacteria Per Cubic Centimeter. ALLEGHENY RIVER AT HULTON. Samples were collected from the "Allegheny River at Hulton," about six miles above Brilliant, once a week during the months of August to November, inclusive, 1897. After this time the samples collected from the river at Brilliant may be taken as fairly representing the river at Hulton. The water supply, furnished by the Suburban Water Company to Oakmont and Verona, is derived from the river at this point. The pump- age is given as about 300,000 gallons daily. The water is obtained from a crib, situated in the river and about 260 feet from the pumping station, to which it is connected by a 12-inch pipe. The crib was built in 1894, of 2-inch x 4-inch hemlock, in a crate style something like the Montrose 286 APPENDIX NO. 2. Crib, but is open on top. It is 96 feet long, 16 feet wide, and 4 feet deep, It is covered with large stones, gravel and sand, about 4^ feet deep. The .average depth of water at low water is about seven feet. The samples were collected from the bank in the current and near the station. Allegheny River at Hulton. (Parts Per 100,000.) Serial Number. Date of Collection. Turbidity. Color. Nitrogen as, Chlorine. Residue on Evapora- tion. Total Hardness. Alkalinity. Sulphuric Acid. Iron. Bacteria Per Cubic Centimeter. Albuminoid Ammonia, Free Ammonia. Nitrites. Nitrates. Total. Suspended. Loss on Ignition. 1897. 93 Aug. 9 Slight .0215.0021 .0000. .0815 1.17 10.1 0.7 4.1 5.58 5.891.10.070 650 115 " 16 Dec'd .0208 0021 .0000.0900 1.10 11.4 2.8 2.8 7.90 5.650.99.100 525 144 I 4 90 Slight .0185 0016 .0000.0638 1.10 9.0 2.4 4.4 5.02 3 730.82.070 1,150 Av'gs, 1 1 1! .0203.0019.00001.0784 1.12 10.2 2.0 3.8 6.17 5.090.97 .080 775 233 Sept. 14 Slight .20 .0133.0024.0000.0450 1.97 14.0 6.4 6.42 5.491.54.040 250 293 " 28 .25 .0174.0028.0000.0900 ! | 2.01 17.2 7.2 3.90 3.79 2.88.062 3,300 Av'gs, .22 ! ! i; )' .0153.0026.0000.0675 1.99 15.6 6.8 5.16 4.64 2 21 051 1,775 316 Oct. 5 V.sl'gt .30 .0162 .0012 .0000.0775 3.12 17.6 8.4 5.01 4.752.23 .068 12,250 351 " 12 Slight .30 .0108 .0010 .0000.0600 2.8415.0 5.8 5.10 4.7011.96 .044 5,700 378 " 19 V. " 30 .0105 0012 .00001.0600 2.79 17.6 7.2 5.80 5.252.61 .050 90,000 410 " 26 V. " .30 .0078 .0014 .0000.0375 3.75 23.2 12.2 5.39 5.202.54 1 066 87,000 Av'gs, .30 .0113 .0012.0000.0587 3.12 18.3 8.4 5.32 4.972.33.057 48,737 439 Nov. 2 Clear .20 .0060.0012 .0000 .0450 3.51 17.8 0.0 6.4 5.28 5.11 2 50 .052 32,000 470 " 9 Slight .20 .0122.0016 .0000 .0525 3.45 19.6 0.4 5.2 4.80 4.65 2.85 066 7,800 491 " 16 Dec'd .35 0266.0054 .0000 .1200 185 26.0 10.8 60 3.31 2.95 1.89 .288 15,010 517 " 23 Slight .30 1.01401.0010 0000 .0675 1.44 12.2 0.6 5.2 2.76 2.31 120 .110 15,700 Av'gs, 1 .26 .0147.0023 1 I1 il .0000.0712 2.56 18.9 2.9 5.7 I 4.04 3.75 2.11 129 I17-627 RESULTS OF ANALYSES. 287 EFFLUENT-HULTON CRIB. Samples were collected of the water which had passed through the crib, once a week during the months of August to November, inclusive, 1897; then once in two weeks until May 1, 1898, and again once a week, until the close of the experiments. These samples were collected from a small netcock on the steam pump. Effluent-Hulton Crib. (Parts Per 100,000.) Serial Number, Date of Collection. Turbidity. Color. Nitrogen as, - - ■ - ■ Chlorine. Residue on Evapora- tion. Total Hardness. Alkalinity. Sulphuric Acid. Iron. , Bacteria Per Cubic Centimeter. 1 Albuminoid] Ammonia. Free Ammonia. Nitrites. Nitrates. Total. Suspended. Loss on Ignition. 1897. 15.6 94 Aug. 9 Clear .0108.0009 .0000.0592 3.53 4.0 7.22 10.16 1.22.030 135 116 " 16 Slight V.Sl'gt .0130.0014 .0000,0605 2.40 13.0 5.4 8.85 6.3( 1.00.090 1,071 145 " 23 .0110|.0018 .0000.0525 4.48 15.2 3.2 7.28 7.27 0.55 .030 135 175 " 30 V. " .35 .0140.0010 1 .00001.0525 3.02 13.6 6.0 6.93 5.42 1.10.040 1,953 Av'gs, .35 1 1 1 .0122.0013.0000.0562 1 1 ! 3.36 14.3 4.6 7.57 7.300.97 .047 823 234 Sept. 14 V.Sl'gt .20 .0094.0016.0000.0450 2.97 14.8 5.2 7.22 6.641.31 .032 68 294 " 28 Slight .20 .0102.0014.0000.0750 3.90 18.0 6.4 5.97 5.77 2.16.058 2,250 Av'gs, .20 .0098.0015.0000.0600 3.43 16.4 5.S 6.59 6.201.73 .045 1,159 317 Oct. 5 Clear .20 .0096.0014.0000.0825 3.68 17.2 6.4 5.70 5.221.85 .046 6,336 352 " 12 V.Slg't .20 .0118,-0005.0000.0825 3.97 16.4 6.0 6.21 5.66 1.20.030 3,846 379 " 19 V. " .20 .0090.0010.0000.0675 3.80 19.6 6.8 6.13 5.802.30.047 34,560 411 " 26 V. " .20 .0080.0016.01X10.0525 5.14 29.2 10.4 6.42 6.042.20.046 39,825 Av'gs, .20 1 1 1 II II .0096.0011.0000.0712 4.15 20.6 I I 1 1 1 7.4 6.11 5.68 1.89.042 21,142 440 Nov. 2 V.Sl'gt .15 .0084 .0014 .0000.045015.34 20.4 0.1 7.6 6.72 6.15 2.23 036 27,000 471 " 9 Clear .15 .0088 .0018 .0000.0525 6.31 22.0 0.0 6.4 6.88 6.65 1.99 030| 2,100 492 " 16 I' .10 .0160 .0058 .0000 .0825 6.22 24.0 0.0 8.0 7.14 6.83 0.89 016; 100 518 " 23 .20 .0068 .0014 .0000.0450 6.07 22.0 0.0 8.4 7.16 6.76 0.99 018; 167 Av'gs, 15 .0100 0026.0000.0562 5.98 22.1 0.0 7.6 | 6.97; I 6.60 1.52 025 7,342 APPENDIX NO. 2. 288 Effluent-Hulton Crib. (Parts Per 100,000.) 958 978 1000 1031 1050 894 932 783 821 857 704 747 632 669 563 598 Serial Number. Ap Av Ma Av bl - & Ay - B H-4 Ay e - 0 >- orcf CL 5? ao (n <kT • • © Date of Collection. OQ co to h-4 OQ to rn L J J f-4 CQ I-1 0Q 1-4 IO 4- -j C W G IO O O' (X b-4 O0 4- - "'I a Ci C7 a 0 lea si' lea : o lea u u lea (. i lea u z - c? Turbidity. ** H-4 io io J-4 io k* i-* _ i-4 )-4 H-4 -4 _4 h-4 F-4 H-1 F-4 •-4 b-4 to i-1 Color. x © © © © © to to to 44 to 10 to © G © © © Ol © © 8 .00 .00 .00 .00 .00 o o " 88 8 888 8 §§ b .004 .004 8 88 Albuminoid Or oi x co x co Ol G 4- CO 05 05 05 co 4*** 4~ Ammonia. O 00 X 4- X >--4 © to Oi © G G 4-" © G to X 4- X X X 8 .00 .00 .00 .00 .00 o 88 8 000 0 0 O .00 .00 8 88 Free to - CO - to I- to to -1 IO >-4 b-4 tO to to h- ■-4 •-4 >--4 Ammonia. o © 4- G G to G 4- GO © to 00 GO G © 00 oo co © G 1 .0000 .0000 .0000 .0000 .0000 | .0000 .0000 0000' .0000 .0000 .0000 .0000 .0000 .0000 0000' .0000 .0000 .0000 lOOOO' 0000' Nitrites. IS c» bbbbb pp f-p b © © © (*> © © 0 © © Nitrates. IO Qt OC M K o Oi 4^ X (X ^4 C^) ^xl X 0 I ^^7 4 |J t 1 1 to G © to b< 01 GO to Oi G to Oi 8 IC © O' Ol O O' oi o< C*~7 Ol Ol 0 Oi 0 G G co co to co co to 05 ~ IO 4^~ 44 CO 4- G । p. 4^ pi w Oi to G G G H-4 4- O O CO b< co fil GO X b to io X X Chlorine. io to o o o o CO Oi IO to O( 0 0 »-4 Oi 00 Oi 4" "^1 •wU Ol H-4 •-1 •-4 -- -4 >-I -4 -4 _4 । ■ । 1 h-4 - 1-t ►-4 to IC r- IO -4 bi 9.2 1.8 2.8 2.4 1.2 3.2 6.0 0.4 7.6 3.2 4.0 Ol O 4^ bo 4^ 0 1.2 7.6 O 1.2 8.8 Total. raw o o o o o o o o o © © © 0 0 0 0 © © p © © Suspended. 5 b b © © © © b f^j f*^ ^0 © © QI b b 2: 2 M to 05 4- G IO IO jP- CO 4- । [ ■ . [ jx , I. Ol co X Ol 07 Oi X Loss on 1-I 4- O X X O io b bo O IO X 4- to G 4^ io x X to b Ignition. 4- pi Oi pi 4- CO 4- 44 G X pi X 74 Oi pl pl X C7 07 X r4 Total Hardness. ^^1 io io - 4- do io > ■ » 1 * 00 00 00 1 ■ 4 bi bo to *1 Oi X O IO O O< CO IO to 0 to 0 Ol © c**1^ c" } X IC 4- 4^ 3.3 3.1 4.7 4.4 4.4 44 05 4>- pl pl O OI C-4 4- G G Ol X io 0 GO 8.8 6.8 Alkalinity. © G G G 4-" 05 <x -1 © G 00 G tO CO 0 ex CO -■ OI © ^^^7 C^, 00 - '^'1 - ^0 4 C J - © Sr bi bi bi co bi 1 [- Z"> X X "^1 4- TO .96 .03 Sulphuric Acid. O X X X O 4- >-4 4 4- 07 C51 IO -4 '■-4 .01 .01 .01 '.01 .01 .01 .01 Si x - IO 88 8 W 00' Iron. G X 4- X X O >-4 to - 000 IC O1 4^ to X X X IC 4^ 1-4 I-4 Bacteria Per g o ( >-1 -4 co 11 - >-4 to Ol 4-4 Oi 00 co O' 'TO Cubic Centimeter. G to Oi Oi CO -4 GO CO co r-") ! | X co 10 V J( It) 4 * • 4^ o C © © © © © G h- 44 05 G I to IC cc G • G . RESULTS OE ANALYSES. 289 Effluent-Hulton Crit). (Parts Per 100,000.) Serial Number, Date of Collection. Turbidity. Color. Nitrogen as, Chlorine. Residue on Evapora- tion. Total Hardness. Alkalinity. Sulphuric Acid. Iron. Bacteria Per Cubic Centimeter. Albuminoid Ammonia. Free Ammonia. Nitrites. Nitrates. Total. Suspended. Loss on Ignition. 1898. 1075June 7 Clear .12 .0040.0016 .0000.0450 4.00 14.0 0.0 4.0 6.22 5.101.07 .004 1,260 1098 " 14 Slight .17 .0040.0018.0000.0225 4.72 14.6 0.3 3.4 6.08 5.581.47 .008 300 1125 " 21 Clear .12 .0046.0008.0000.0225 5.13 15.6 0.0 4.4 6.00 6.130.28 .009 1154 " 28 .10 .0040.0018.0000.0450 4.61 15.8 0.0 3.6 6.36 5.940.89 .008 320 Av'gs, .13 '1)11 .0041.0015 .0000.0337 4.61 15.0 1 1 1 II II 0.1 3.8 6.16 5.690.93.007 490 1l74July 6 Clear .17 .0040.0024.0000.0975 3.76 13.8 0.0 3.6 6.10 5.500.38.010 2,450 1200 " 12 .27 .0048.0016.0000.0675 3.27 13.4 0.0 4.0 5.84 5.201.20.006 6,420 1222 " 19 it .20 .0040.0016.0000.0675 5.40 19.6 0.0 5.0 7.28 6.550.89.008 17,100 1247 " 26 .22 .0058.0014.0000.0525 3.88 16.2 0.0 5.4 6.39 5.341.82.010 17,800 Av'gs, .21 .0046.0017 II : .0000.0712 4.08 15.7 0.0 4.5 6.40 5.65 1.07 .008 10,950 1276 Aug. 2 Slight .20 | | | | .0040.0016.0000.0525 4.34 18.2 0.6 5.6 7.30 6.621.34.018 14,800 1298 " 9 Clear .20 .0062.0016.0000'.0525 4.75 17.8 0.0 5.0 8.14 7.161.101.014 250 1328 " 16 .10 .0040.0022 .0000 .0525 4.60 16.0 0.0 3.0 7.00 6.620.92.016 300 1364 " 23 11 .20 .0062.0022.0000.0300 3.68 1 1 1 ' 13.6 0.0 3.5 5.62 5.580.79.004 1 100 Av'gs, .17 .0051 I i II .0019.0000.0469 4.34 16.4 0.1 4.3 7.01 6.491.04.013 3,860 VERONA TAP. Samples of the "Tap Water" supplied in Verona were collected once a week, during the months of August to November, inclusive, 1897, then once in two weeks to May 1, 1898, and thereafter once a week, until the close of the experiments. The water supply is pumped a distance of about three miles to the village, and into the distributing system; the surplus passing into a reservoir of 1,500,000 gallons capacity. The sam- ples were collected from a tap near the railroad station. 290 APPENDIX NO. 2. Verona Tap. (Parts Per 100,000.) Serial Number. Date of Collection. Turbidity. •JOIO3 Nitrogen as, Chlorine. Residue on Evapora- tion. Total Hardness Alkalinity. Sulphuric Acid. 1 Bacteria Per Cubic Centimeter. Albuminoid Ammonia. Free Ammonia. Nitrites. Nitrates. Total. Suspended. Loss on Ignition. 95 117 181 1897. Aug. 9 " 16 " 30 Clear .id .0106 .0066 .0104 .0007 .0018 .0018 .0000 .0000 .0000 .06004.30 .03754.50 .0900 3.70 li 15.4 15.2 13.0 5.1 4.0: 4.2 7.60 10.45 7.03 11.72 7.67 6.78 1.07 0.86 1.27 1 .035 .020 .030 126 81 84 Av'gs, .10 i .0092.0014 .0000 .0625 4.17 14.5 ... 4.4 8.36 8.72 1.07.028 97 219 235 267 297 Sept. 7 " 14 " 22 " 28 V.sl'gt Clear 45 .00 .0104.0012 .0102.0014 .0104.0012 .0098.0007 1 .0000 .0375 3.73 15.4 .0000 .0488 2.89 14.8 .0000.0375 3.44 15.8 .0000'.0750 4.38 19.6 2.8 4.8 4.8 7.2 5.97 6.79 6.34 7.25 7.13 6.45 6.19 7.16 I 0.72.008 1.16.010 0.86.004 1.96.020 20 17 134 1,050 Av'gs, .07 .0102.0011 .0000 .0497 3.61 16.4 4.9 6.59 6.73 1.17 .010 305 330 Oct. 5 359 " 12 380 " 19 412 " 26 Clear V.sl'gt Clear < c .20 .10 .10 .10 .0106 .0146 11)076 .0018 .0010 .0012 .0014 .0000 .oooc .0900 .0600 .0675 .0375 4.16 20.8 3.64 18.8 3.58 18.0 4.43 21.6 ::: 7.6 8.8 6.4 8.8 7.69 5.80 5.75 5.48 7:35 5.42 5.21 5.28 I.S2.044 2.02.022 2.06.040 2.09.006 j 1,783 1,820 1,442 1,778 Av'gs, .12 .0103.0013.0000.0637 3.95 19.8 1 1 1 1 II 1 ... 7.9 6.18 5.81 2.00.028 1,706 438 Nov. 2 472 " 9 493 " 16 530 " 23 Clear (( .10 .10 .05 .20 1 1 .0130.0014.0000.0375 .0108.0018,0000.0450 .0168.0026.0000.0600 .0064.0014.0000.0375 5.42 18.8 5.11 18.8 5.06 22.8 5.99 20.8 0.0 0.0 IM (i.4 6.8 8.8 6.4 5.90 6.08 6.94 2.06 5.24 5.551.72.004 5.902.30.004 6.331.58.004 6.391.72.006 2,600 210 87 79 Av'gs, .11 .0117.0018.0000 .0450 5.39 2(1.3 0.0 7.1 6.04 L.83.004 744 562 Dec. 7 599 " 21 Clear .10 .10 .0064.0014 .0052;.0010 1 .0000l.0825 l6.5i 20.0 .0000 .0375 6.25 20.8 '1 I II 0.0 0.0 6.8 6.4 8.19 6.90 7.050.79.002 6.45,1.27.006 1 1 175 1 Av'gs, 1 1 .10 .0058.0012.0000.0600 6.38 20.4 i 1 r 1 II 1 o.c 6.6 1 7.54 1 1 1 6.751.03.004 175 1898. 630 Jan. 4 670 " 18 V.sl'gt JO .0040.0022.0000.0675 2.60 23.2 Clear .00 .0038.0026.0000.0600 5.21 20.4 0.1 o.c 9.2 7.2 7.1 C 6.4C 6.51 1.23.004 5.760.89.008 444 323 Av'gs, .05 .0039.0024.0000.0637 3.90 21.8 o.c 8.2 6.78 6.131.06.001 383 RESULTS OF ANALYSES. 291 Verona Tap. (Parts Per 100,000. ) Serial Number. Date of Collection. Turbidity. Color. । Residue on Evapora- tion. Total Hardness. Alkalinity. Sulphuric Acid. || Bacteria Per Cubic Centimeter. Nitrogen as, Chlorine. Albuminoid Ammonia. Free Ammonia. Nitrites. Nitrates. Total. Suspended. Loss on Ignition. 705 1898. Feb. 1 Clear .15 .0032 .0014 .0000 .0825 4.92 17.2 0.0 6.9 5.80 5.500.61 .008 1,980 748 " 16 .07 .0042 .0010 .0000 .0750 4.92 15.2 0.0 4.8 6.04 5.280.92 1 .008 130 Av'gs, .11 .0037 .0012 .0000 .0787 4.92 16.2 0.0 5.8 5.92 5.39 0.76 .008 1,055 785 Mar. 1 Clear .10 .0044 .0022 .0000 .0450 4.68 16.0 0.0 5.6 6.44 5.401.07 .008 37 822 " 15 I c .15 .0034 .0008 .0000 .0450 4.20 14.8 0.0 3.6 6.44 5.450.48 .012 160 855 " 29 Ct .12 .0068 .0030 .0000 .0450 4.48 16.4 0.6 6.2 6.22 5.320.68 .012 1,267 Av'gs, .12 .0049 1 .0020.0000 i .0450 1 4.45 l 15.7 0.2 6JI 6.37 5.390.74 .011 488 895 Apr. 12 V.sl'gt .17 .0058 .0014 .0000.0675 4.23 14.4 0.0 3.6 5.40 4.600.68 .010 560 933 " 26 Clear .15 .0062 .01)18 .0000.0525 3.62 13.0 0.0 4.4 4.66 4.37 0.58 .010 560 Av'gs, .0060 .0016 .OOOo|.O6OO 3.92 13.7 0.0 4.0 5.03 4.48 0.63 .019 560 979 May 10 " 17 V.sl'gt .20 .0050 .0016 .0000 .0300 3.26 14.4 0.0 4.4 4.32 4.16 0.55 .015 920 1001 Clear .12 .0042 .0012 .0000 .0075 3.25 12.0 0.0 3.4 5.22 4.52 0.58.006 1032 " 24 c c .20 .0072 .0018 .0000 .0300 2.78 12.2 0.0 3.6 5.20 4.36 0.58 .004 620 1051 " 31 Cl .10 .0054 .0006 .0000 .0450 3.40 11.6 0.0 4.2 5.30 4.50 0.52 .004 800 Av'gs, .15 .0054 .0013 .0000 .0281 3.17 12 J) 0.0 3.9 5.01 4.380.56 1 .007 780 1076June 7 Clear .15 .0042 .0008 .0000 .0225 4.30 14.8 0.0 4.0 6.18 5.280.58 .003 2,800 1099 " 14 V.sl'gt .17 .0038 .0018 .0000 .0225 4.22 14.9 0.2 3.9 5.68 5.460.34 .010 370 1128 " 21 Clear .17 .10 .0078 .0044 .0012 .0000 .0300 4.65 17.2 0.0 4.6 5.80 5.900.41.006 300 1155 " 29 c c .0010 .0000 .0450 4.90 16.8 0.0 4.6 6.44 6.100.89 .009 41 Av'gs, .15 .0050.0012 .0000 .0300 4.52 1 15.9 0.0 4.3 6.02 5.680.55 1 .007 880 1175 July 6 Clear .17 .0044 .0020 .0000 .0750 3.88 14.2 0.0 5.4 6.18 5.620.24 I ' .008 76 1201 " 12 cc .27 .0050 .0016 ,000( .0750 4.38 16.2 0.0 5.0 6.32 5.901.21 .008 3,360 1223 " 19 .0048 .0012 .0000 .0675 4.41 164 0.0 4.1 6.18 5.900.79 .012 8,400 1248 " 26 cc .0052 .0018 .oooc .0451 4.48 1 18.C 0.0 1 5.4 6.62 5.8C 1.72 .008 1,000 1 Av'gs, .21 .0048 .0016 .000( .0656 4.29 o.c 6.32 5.8C >0.99 1.009 3,210 APPENDIX NO. 2. 292 Verona Tap. (Parts Per 100,000.) CO CO K IO z>z yz o Serial Number. Av'gs, Aug. 2 " 9 " 16 " 23 1898. I Date of Collection. Sligh Clea) u it Turbidity. • C" .20 .20 .20 .20 Color. .0050 .0040 .0058 .0048 .0054 Albuminoid Ammonia. Nitroc .0020 .0014 .0022 .0022 .0024 Free Ammonia. .0000 iiii Nitrites. M <Z) o .0450 .0525 .0525 .0300 Nitrates. 4.49 CO 4- 4- o o io to o to Chlorine. I 16.6 18.4 17.3 16.0 14.6 Total. 1 M rd 1 0.9 0.0 0.0 0.0 Suspended. o 3 1IDUE ON ARORA- 4- 4.9 5.4 4.8' 4.2 Loss on Ignition. 7.17 7.20 8.20 6.80 6.50 Total Hardness. 29'9 1 6.43 7.12 6.25 5.48 Alkalinity. 1.02 1.03 1.16 1.13 0.75 Sulphuric Acid. s .010 .010 .004 .002 Iron. JO IC 7,650 325 520 300 Bacteria Per Cubic Centimeter. ALLEGHENY RIVER AT WILDWOOD. Samples were collected of the "Allegheny River at Wildwood," about one and one-half miles above Brilliant, once a week from the last of June to the last of October, 1897, and once in November, 1897. After this the samples collected at Brilliant may be taken as representing the river at Wildwood. The water supply of Wilkinsburg, some neighboring towns, and of the 37th Ward of Pittsburgh, is furnished by the Pennsylvania Water Company. The water is obtained from the Allegheny River at Wild- wood and, since June, 1897, from a crib situated in the middle of the river. This crib is connected, by a 24-inch pipe in the bed of the' river, with a tunnel on the shore, reaching from the low water mark to the pump well. The crib is 304 feet long, 32 feet wide, and 4 feet deep, and is built of 2-inch x 8-inch planks, with two-inch open spaces on the top and sides, and nothing on the bottom. The bed of the stream was dredged and the crib floated out and sunk. Upon the crib and all around it there was placed one foot of large stones, then one foot of coarse gravel, and then three feet of river sand. It is said, that underneath the crib there is thirty feet of gravel in the bed of the stream. The average daily pumpage is about 1,500,000 gallons. These samples were collected from a boat over the crib. RESULTS OF ANALYSES. 293 Allegheny River at Wildwood. (Parts Per 100,000.) • Residue on ,53 f g Nitrogen as, Evapora- tion. 8 Serial Num Color. <1 s Date of Coll Turbidil Albuminoid Ammonia. > Nitrites. Nitrates. § Total. Suspended. ff i Alkaiin Sulphuric 1 Bacteria Cubic Centi 1897. 20June 23 ... .0120 .0000 .0000 .0000 1.60 10.0 6.0 7.60 1.40 .000 I 35Julv 7 .OISO .0000 .0000 2.50 13.2 6.0 6.20 ... 1.04 43 " 13 Slight .0162 .0016 .0003 .0002 .0015 1.80 12.4 0.8 5.6 4.97 7.501.35 .002 520 53 " 19 u .0182 .0013 .0610 1.47 14.4 3.6 6.2 5.75 6.500.96 .050 (59 - 29 Mud'y .0031 .1334 0.95 22.9 13.9 4.0 4.07 4.500.89 .110 11,350 Av'gs, .0201 .0027 .0001 .0490 1.68 15.7 4.6 5.4 5.25 1 6.161.06 1 .054 5,935 Aug. 4 Slight .0240 .0030 .0001 .0950 10.8 1.1 4.0 4.13 5.70 0.76 .120 1,225 " 11 Mud'y .0395 .0035 .0000|.0814 3.75 44.828.2 9.6 5.80 6.151.03 .180 3,600 123 " 18 Slight .0268 .0018 .0000 .0600 1.56 20.0 10.6 3.0 6.72 4.51 0.74 .220 11,200 148 " 24 V. sl'gt .0204 .0028.0000 .0450 1.31 8.6 4.2 5.30 3.65 1.00 .020 5,200 176 " 30 V. " .40 .0141 .0009 .0000 .0600 1.68 10.4 ... 4.8 6.51 4.501.03 .030 6,500 Av'gs, .40 .0250 .0024 .0000 .0683 1.89 18.9 8.0 5.1 5.69 4.900.91 .114 5,545 209 Sept. 7 V. sl'gt .40 .0122 .0014 .0000 .0600 1.88 11.2 4.4 5.42 4.90 1.44 .026 7,425 242 257 " 14 " 21 Slight J5 .0112 .0108 .0012 .0028 .0000 .0000 .0000 .05752.14 .03002.62 13.2 16.0 ... 5.6 5.6 6.18 5.70 5.40 5.40 1.30 1.72 .026 .034 300 825 291 " 27 u .25 .0118 .0012 .0675 I2-61 14.0 4.0 3.70 3.77 3.13 .046 3,600 Av'gs, .27 .0115 .0016.0000 i .0537 2.29 13.6 4.9 5.25 4.87 1.90 / .033 3,037 319 344 381 Oct. 5 " 11 Slight V. sl'gt .35 .25 .0100 .0158 .0012.0000 .0020.0000 .0775 .0450 2.89 2.97 15.2 17.6 7.0 6.4 5.13 4.56 4.682.41 4.622.09 .046 .064 3,375 13,400 " 18 Slight .20 .0120.0020.0000 .0750 2.98 15.6 4.8 4.90 4.642.64 .030 117,500 403 " 25 V. sl'gt .20 .0070 .0018 .0000 .0750 3.83 17.6 6.0 5.40 5.17 2.51 .044 74,900 Av'gs, .25.0112.0017 .0000 .0681 3.17 16.5 ... 6.0 5.00 4.78 2.41 .046 52,294 538 Nov. 29 Clear .00 .0068 .0010 l| 1 .0000 .0600 2.75 18.8 0.0 s. 8.31 7.81 1.37 .016 APPENDIX NO. 2. 294 EFFLUENT-WILDWOOD CRIB. Samples were collected from the water which had passed through this crib, about once a week during the work, except in March and April, 1898, when the pump was not running in the day time and it was incon- venient to secure samples. These samples were collected from a tap upon a three-quarter-inch pipe, which was connected with the force main just outside the pumping station. Effluent- Wildwood Crib. (Parts Per 100,000.) 210 243 258 292 86 103 124 149 177 36 44 54 71 '8 Serial Number. Av'gs, Sept. 7 " 14 " oi " 27 ckT Aug. 4 " 11 " 18 " 24 •" 30 Av'gs, July 7 " 13 " 19 " 29 1897. June 23 Date of Collection. Clear (t c t 4 ( Clear Clear c ( u Turbidity. o .20 .00 .00 .00 1 • • ; • Color. - -। 8 CH .0048 .0062 .0056 .0040 1200' .0062 .0110 .0052 .0060 .0070 .0051 .0070 .0046 .0058 .0032 0W0' Albuminoid Ammonia. Nitrogen as, .0017.0000 .0026.0001 .0018.0000 .0012.0000 .0014.0000 .0024 .0018 .0024 .0023 .0028 .0025 .0027 8888 IC tc O' CO 4- IC O .0000.0000 Dree Ammonia. § IC mil .0002 .0000 .0001 .0003 .0005 N itrites. .0844 .0450 .2250 .0225 .0450 Zito- .0592 .0370 .0300 .0375 .0450 68'10' .0000 .0010 .0300 .0445 8 Nitrates. • 2.03 2.19 2.15 2.62 1.45 2.12 1.81 1.99 1.99 117 2.10 1.85 2.31 2.20 8 Chlorine. . 14.6 14.6 15 4 15 6 14.3 15.0 14.0 14 6 13.6 14.4 15.6 14.S 16.0 17.3 14.5 14.4 Total. Residue on Evapora- tion. Suspended. o 4.0 4.8 6.8 6.8 CO 0'9 F9 r 6.4 6.8 6.9 4.3 bo Loss on Ignition. 8.6210.41 8.36 8.50 7.10 10.54 9.61 CD C p C O 4- CO - O IC (X IC O' 4- 8.00 7.30 9.40 9.10 10.00 Total Hardness. 9.85 10.01 11.11 10.68 13.43 1 17.90 17.35 11.10 10.70 10.12 13.83 8.00 16.00 17.50 Alkalinity. 1.10 0.81 0.89 1.03 1.68 0.75 1 0-52 0.69 0.88 0.86 0.82 1 1.00 1.07 0.92 1.14 0.87 1.58 Sulphuric Acid. .011 .012 .020 .010 .004 .027 .010 .015 .008 .002 .100 .010 .005 .020 .005 .000 Iron. co 12 160 148 139 88 50 262 106 188 164 8: 5: Bacteria Per Cubic Centimeter. RESULTS OF ANALYSES. 295 Effluent- Wildwood Crib. (Parts Per 100,000.) ic 980 co 899 642 CO ^4 OR ic 489 432' 469 382 404 £ Serial Number. Av'g - - - Abjv A pr. Mar. Av'g - 1898 Jan. crcT Dec. Av'g - Noy. Av'g 1897 Oct. Date of Collection. x ^1 ■-u o CO g co jn k-1 4- * tc tc 4° 00 7- X ■-1 Ly ■ GO o Q 0 a GO a 0 - 7. Q 2 no sr ~ " pa c ?r pa Turbidity. H CK? *4 p 00' 0 0 2 00- 00' 00' s ts 0 .00 .00 g .00 .00 .00 .00 Color. .0054 .0058 .0042 .0068 W CO .. CO_ 8 ' a .0039 8 W ns>S .0056 .0072 .0068 .0046 .0038. .0040, .0020 .0038. .0064 Albuminoid Ammonia. o g IO 100 001 002 100 .001 - 001 to 100 LOO 100 LOO 002 LOO o3 002 001 TOO 001 001 001 001 Free Ammonia. - - J t~> C/i IO CO o ■4 10 X IC 4- ■4- 1 Xz X tc IC IC tc 4- IC Q 2 0000 § 0000 8 0000 0000 .0000 0000 1 8 8 0000 0000 0000 01X10 O 0000 0000 0000 1 0000 0000 0000 0000 Nitrites. z ► CA s o .0450 .0075 .0300 0000' -- . . •^1 O' 8 <O< x 0090' .1200 .0600 5 1 .0750 .0525 .0525 .0337 g .0075 .0525 .0450 .0619 .0750 .0375 p p IC IC Nitrates. t-A -1 _1 k-U j-1 hu co 2.44 o< tc IC co C14 4- co co 2.94 CO IC IC IC g t -pl o ic Ci io to *4 £88 0 X X .20 .20 X CH X Chlorine. , 1 ■ 1 i । 1 1 1 1 । । - IO IC to ic IC ' * r-' -1 i-U I-U 4- 4- JC X 0.8 0'0 0.0 tc !0.8 X to to bi 0.4 1.8 ^4 8.0 7.2 8'9 f8 Total. O o o o o 0 0 000 0 0 c 0 0 Suspended. " 5 ® tC X ■ C~' c> C 3 GG ' , ' , G_) (O ? § w Loss on Ignition. 4- 3.4 to 4.2 4^ 3.2 74 Os tc 4~ >1 9.2 5.8 6.8 co ^1 q GO 'Ji ^4 ic bi Ci 4- p 8.0 8.4 o Ci 02 Ci CR cn CO - r 4- co 9° CO GO GO O GO CO CO X O O X X 0 co Total Hardness. tC i \* j J ». * Ci . . 1 I'O GO x to O ic co 0 0 co 4^ * . 1*7^ b i* gc 1 00 / GO (*7 ^o IO GO G > .77 tc CH 4- O X 0 CH -M 6.1 5.8 5.0 to os CO J-j GO 8.2 8.8 7.9 7.9 8.4 ^7 9.0 8.7 X X #X X Alkalinity. □□ o GO ,- §- -5- 1 1 GO to „ OS ^0 co 4- X IC Ci CH Cl HU uu GO CH _u J-u co do CO 4- _! 4- 4- Cn 00 O O CO CH Sulphuric Acid. -. 00 t o 01 tT' CO U-4 GO c?7 CH O Ci CR tc CR Ci - I uu .010 HO- .008 .010 800' .030 .041 .(>17 .040 .008 .004 .012 .008 .012 .015 .011 660' 88 .016 ,(X)4 .024 .018 .020 Iron. 850 029 I s? to 71 688 55 IC IC 86t'L 18 L 89 i-I "10 X 260 - I tc 3,980 580 4"* 1,988 4,120 116 542 Bacteria Per Cubic Centimeter. 296 APPENDIX NO. 2 Effluent- Wildwood Crib. (Parts Per 100,000.) Serial Number. Date of Collection. Turbidity. Color. Nitrogen as, Chlorine. Residue on Evapora- tion. Total Hardness. Alkalinity. Sulphuric Acid. Iron. Bacteria Per Cubic Centimeter. Albuminoid. Ammonia. Free Ammonia. Nitrites. Nitrates. Total. Suspended. Loss on Ignition. 1898. 1104 June 14 V. sl'gt'.17 .0048.0012 .0000 .03001.94 13.4 0.0 4.6 6.98 6.701.47 .010 800 1151 " 27 Clear .10 .0038.0016'.0000 .0525 1.92 12.8 0.0 3.0 7.33 6.900.79.008 220 Av'gs, .13 .0043 .0014.0000.0412 1.93 I l ! 13.1 0.0 3.8 7.15 6.801.13 .009 510 1183 July 7 Clear .10 1 1 |l .0048.0018.0000.1050 1.60 12.6 0.0 4.1 7.32 6.96 1.23 .014 720 1202 " 12 cc .17 .0038 .0016.0000.0600 2.00 14.0 .0038.0014.0000.0675 2.10 14.4 0.0 5.4 7.84 7.101.27 .006 1,050 1229 " 20,V.sl'gt .10 0.0 5.0 7.90 7.061.82 .008 1,220 1249 " 26 Clear .10 .0050 .0018.0000.0600 3.16 16.1 0.0 3.8 8.45 7.052.51 .006 500 Av'gs, .12 .0043 .0016 .0000 .0731 2.21 14.3 0.0 1.6 7.88 7.04 1.71 .008 870 1279 Aug. 2 Slight .20 .0038 .0016.0000.0600 2.92 37.0 9.8 4.6 8.26 7.54|1.65|.008 850 1300 " 9 Clear .17 .0064 .0014.0000.04501.96 21.6 0.0 7.2 8.34 7.644.02.012 8,700 1339 " 16 u .20 .0044 .0020 .(XXX).0600 2.05 16.2 0.0 5.0 9.04 7.941.54^.006 425 1365 " 23 V. sl'gt 17 .0048 .0024.0000.02251.62 16.2 1 1 1 0.8 5.0 8.54 6.202.55.008 3,900 Av'gs, 1 .18 .0048.0018.0000.0469 1 1 2.14 22.7 2.6 5.4 8.54 7.33 1 2.44.008 1 3,470 WILKINSBURG TAP. Samples of the "Tap Water" in Wilkinsburg were collected once a week during the months of September, October and November, 1897, and then about once a month until the close of the experiments. The water supply is pumped from Wildwood to an open reservoir of 6,000,000 gallons capacity, about one mile distant from the river. From this basin it is distributed throughout the service system. The samples were col- lected from a tap near the corner of Wood Street and Penn Avenue. RESULTS OF ANALYSES. 297 Wilkinsburg Tap. (Parts Per 100,000.) - Serial Number. Date of Collection. Turbidity. Color. Nitrogen as. Chlorine. Residue on Evapora- tion. Total Hardness. Alkalinity. Sulphuric Acid. c 1 Bacteria Per Cubic Centimeter. Albuminoid Ammonia. Free Ammonia. Nitrites. Nitrates. Total. Suspended. Loss on Ignition. 232 1897 Sept. 13 " 21 Clear .20 .0086 .0018.0000 .0150 2.07 12.S 4.4 9.55 9.21 1.27 .016 18 259 .(XI .0060 .0010.0000 .0488 2.56 15.8 6.4 9.02 9.66 0.99 .020 14 285 " 27 .10 .0072 .0012 .0000.0300 2.59 16.8 7.2 9.50 9.97 0.99 .018 58 Av'gs, .10 .0073 l| .0013.0000.0313 2.41 15.1 1 1 II 1 6.0 9.36 9.61 1.08 .018 30 312 Oct. 4 Clear .30 .0076;.0016.0000.0600 2.57 18.0 7.6 10.9110.53 1.75 .015 148 343 " 11 < 1 .30 .0072.00101.0000.1275 2.63 18.0 7.2 9.76 8.621.47.005 311 369 " 18 .00 .0078.0018 .(XXX) .1350 3.05 18.0 7.2 10.80 9.101.78.014 398 " 25 V.sl'gt.00 .0080.0028.0000.0375 3.02 19.2 o.z 8.94 8.601.72.032 2,820 Av'gs, .15 .0076.0018.0000.0900 2.82 18.3 1 1 1 1 II 6.8 10.10 9.211.68.016 1,093 428 Nov. 1 Slight .00 .0140 .0024 .0000.0375 3.54 18.8 0.4 9.6 9.60 9.31 1.92.004 13,860 460 " 8 Clear .00 .0076 AX)16 .0000.0600 3.30 22.4 0.0 8.8 8.90 8.90 2.13.008 775 488 " 15 c t .00 .0086 .0026 .0000.0150 3.69 .0000.0600 2.66 1 II 20.8 0.0 9.6 9.54 8.92 1.92.008 236 508 " 22 Slight .10 .0058 .0008 20.4 0.2 4.8 8.34 7.73 1.681.036 1 100 Av'gs, .02 .0090.0018.0000 .0431 3.30 20.6 0.1 8.2 9.09 1 8.711.91.014 3,743 554 Dec. 6 Dec'd .20 .0088 .0014 .0000.0750 2.1 HI 22 4 2.6 7.6 10.32 9.20 1.27 .116 280 589 " 20 Mud'y II .20 .0148 .0012 .0000,.0525 | 2.95 33.6 13.2 4.8 9.03 8.70 1.47 .330 Av'gs, .20 .0118.0013 .0000.0637 2.92 28.0 7.9 6.2 9.67 8.95 1.37 993 280 1 1898. 659Jan. 17 Slight .20 .0080 .0014.0000.07501.26 1 1 1 10.8 0.2 3.6 2.40 2.01 1.27 .120 5,340 736 Feb. 14 Slight .12 .0048 1 .0022.0000.2325 1.48 12.8 0.4 5.6 5.22 4.211.47 .085 2.M2 936 Apr. 26 Clear .15 .0062 .0012.0000 .0375 1.51 12.0 0.0 5.2 6.38 5.70 1.13 .010 274 1216; July 18 Slight .20 .0046 .0018.0000 .0600 2.55 15.8 0.4 5.2 7.32 6.88 1.34 .010 540 1252 V.sl'gt .17 .0056 .0018.0000 .0525 3.24 16.( 0.0 4.5 8.40 7.10 2.41 .006 : 1,100 Av'gs, .18 .0051 1 1 II .0018.0000.05622.89 I 1 15.9 0.2 4.S 7.86 6.991.87 .008 820 298 APPENDIX NO. 2. EFFLUENT-SHARPSBURG CRIB. Samples were collected of the water after passing through this crib, once a week in May, 1898, and once in two weeks during the months of June, July, and August, 1898. The water supply for Sharpsburg is de- rived from the Allegheny River, about one mile below Brilliant on the opposite side. Since 1893, a crib, 100 feet long, 8 feet wide, and 5 feet deep, has been in use; which is connected with the pump well by an 18-inch pipe, 800 feet long. The crib has about two and one-half feet of river material over it, but is made tight down two and one-half feet; the remainder of the sides and the bottom being open. The width of tim- bers and of openings is six inches. Low water mark is about three feet above the top of the crib. The water is delivered directly into the piping system from the pumps. The samples were collected from a tap upon the ptimps. Effluent-Sharpsburg Crib. (Parts Per 100,000.) 1180 1226 1080 1132 957 981 1012 1056 Serial Number. Av'gs, Av'gs, to Av'gs, 1898. May 3 " 10 " 17 " 31 Date of Collection. Slight V.sl'gt V.sl'gt Dec'd ^2 Turbidity. to 8 o co .20 .40 i c .17 99 ^20 .27 Color. | o .0104 .0088 .0124 .0068 .0180 9900' .0042 .0090 .0036 .0056 Albuminoid Ammonia. o .0016 .0016 .0016 .0014 .0018 6100' .0018 .0022 .0020 .0018 Free q Ammonia § g 88 88 8 .0000 .0000 i .0000 .0000 .0000 .0000 Nitrites. z ► ~l 09Z0' O9zo- 0080' .0300 .0300 .0375 .0450 .0225 .0225 .0600 Nitrates. 2.05 orz OZ'l | r 2.18 1.70 1.85 1.41 2.30 2.00 Chlorine. 6 81 8'11 19.0 11.2 26.8 15.2 i!2.0 125.2 15.5 Total. J 4'0 0.8 0.0 Lt 0'0 p 0.0 0.4 0.0 1 0.0 ! Suspended. 3 g 2 0'4 4- CO Lu 0'9 4'Ll 0'4 0'4 Loss on 4 p Ignition. 25 ft 06'4 96'8 45'4 80'4 0F4 P £ 4.88 5.08 10.80 6.60 Total Hardness. 4.02 3.87 4.18 3.59 3.58 3.60 5.11 4.70 3.96 7.10 4.70 Alkalinity. IO I-1 c io Cl -1 1.22 1.03 1.73 1.20 1.54 2.93 1.27 Sulphuric Acid. I ' 910' .020 .010 o 040' 400' .021 1 .028 .030 .012 .015 Iron. 13,400 000'81 008*81 20,500 11,100 3,710 2,300 4,300 800 7,450 Bacteria Per Cubic Centimeter. RESULTS of analyses. 299 Effluent-Sharpsburg Crib. (Parts Per 100,000.) 1273 1337 Serial Number. Av'gs 1898. Aug. " 1 Date of Collection. o to . * Slight 4 4 Turbidity. bo to O O' Color. .008. .006- .010( Albuminoid Ammonia. o * 22 Free 118 )20 Ammonia. w o s Q O 22 Nitrites. M 88 >• to tO to Nitrates. to 5 2.48 5 1.98 Chlorine a 97i 20.8 1. 14.4 2. Total. Suspended. Residi Evapc TIO> 2 7.0 6' 3.8 Loss on Ignition. r w w 03 5.62 5.14 Total Hardness. 4.42 4.82 4.02 Alkalinity. -* 1.9 1.3 Sulphuric Acid. zc ro o p p Iron. 4^^ ^^4 - to Bacteria Per ooe 008 00g Cubic Centimeter. ALLEGHENY RIVER AT ETNA. Samples were collected of the "Allegheny River at Etna," two miles below Brilliant upon the opposite side, once a week during the months of August to November, inclusive, 1897: then once in two weeks for the next three months, and occasionally during the remaining time. The water supply of Etna is derived from the river at this point and, since January, 1898, from a crib situated in the river, and connected with the pumps by a 12-inch suction pipe. The crib is a wooden box, 40 feet long, 16 feet wide, and 4 feet deep, perforated with many openings. It was sunk in place and covered with stone, river gravel, and sand, about four feet deep. The average daily pumpage is about 350,000 gallons. The samples were collected from lumber rafts moored to the shore. Allegheny River at Etna. (Parts Per 100,000.) 173 104 125 155 Serial Number. Av'gs, o to 1897. Aug. 11 " 18 Date of Collection. - - Mud' y Slight Turbidity. M Color. .0256 .0176 to £ Albuminoid Ammonia. Nitkoc .0020 i .0016 w 9800' Free Ammonia. .0000 .0000 8 0000' 0000' Nitrites. I .0937 O' 4^ IO 4- Nitrates. 6F L 1 99'1 1.43 1.74 Chlorine. 21.2 GO 9.2 46.0 20.0 Total. Re? IN 34.8 10.4 Suspended. o z - s p a Loss on Ignition. io bs O' 05 V, 90'9 5.85 5.46 i< L, Total Hardness. 66'f 4- 00 6.61 5.25 Alkalinity. 1.23 1.10 1.00 0.86 Sulphuric Acid. IC o o .034 ot<7 08 T' Iron. 6,850 5,600 oeri Bacteria Per Cubic Centimeter. ; 300 APPENDIX NO. 2. Allegheny Hirer at Etna. (Parts Per 100,000.) 726 765 647 687 S co 443 474 497 527 546 328 354 386 414 8wwo Serial Number. Av'gs, Feb. 7 " 22 Av'gs, 1898. Jan. 11 " 25 Av'gs, Dec. 14 " 28 Av'gs, Nov. 2 i " 8 " 16 " 24 " 30 Av'gs, 98 61 „ 51 ,, 9 'PO Av'gs, CO h_ ' 8 Date of Collection. co ' Clear Slight Slight V.sl'gt Dec'd V.sl'gt Slight Clear V.sl'gt „ 'A „ 'A », 'A I$js-A to Slight C 4 V.sl'gt Turbidity. to .25 .27 io io co Ci o S L 08' 1 .28 co co co to to O O CI o to .30 .30 .20 .20 CO LO tO 4- O O CJ< O Color. g .0052 .0048 1 .0088 .0106 - s .0108 .0096 .0170 .0120 .0144 .0288 .0144 .0154 8910' .0188 .0160 .0122 .0144 .0166 2 2 2 S GO CO to CO Ci GO IO Albuminoid Ammonia. Nitrogen as, g .0026 .0018 io 88 IO IO c© g .0028 .0036 8 to .0048 .0038 .0240 .0020 .0016 g to .0014 .0032 .0022 .0048 .0020 .0028 1.0016 .0012 .0024 Free Ammonia. .(XXX) 0000' 0000' i .0000 .0000 0000' 0000' oooo- i .0000 .0000 .0000 .0000 .0000 .0000 iiii i 0000' 0000' 0000' 0000' Nitrites. 8 .1500 I-i to .1425 .1200 s .0675 .0825 W O .0450 .0450 .0900 .0375 .0975 .0712 .0900 .0600 .0600 .0750 .0643 .0750 .0412 .0600 '.0812 Nitrates. ic o io co o io 1.38 0.93 on o 1.39 1.80 to io 4.73 3.95 2.53 2.13 1.27 3.69 2.94 3.20 4.61 4.00 to w o to to to to to bo P f-1 I-1 o o o Chlorine. ►-* 10.2 10.8 14.8 11.6 13.8 16.0 11.6 b< 4^ bs 4- to o 1 681 0'81 921 14.1 10.8 13.2 15.0 17.6 Total Residue on Evapora- tion. 0.2 0.0 0.4 2.4 4.8 to 3.6 0.6 W 0.0 0.4 7.2 0.3 5.6 : : : : Suspended. 3.4 JO 4^ bo O 4.2 k ! 4.0 5.0 W C5 bi 4- Cl co 8.0 6.4 7.2 3.6 6.4 7I | 5.6 7.2 7.2 10.4 Ci '-I bo w o 4- Loss on Ignition. 3.16 3.16 89'1 W5 2.64 2.86 2.42 es't 1 5.98 5.21 5.90 2.93 2.73 [ ' 98'9 t9'9 5.73 5.36 5.12 5.94 5.52 5.22 7.05 5.98 3.84 Total Hardness. Q P ! 2.13 1.44 2.22 2.30 2.14 4.07 5.74 4.93 5.10 2.37 2.22 5.45 4.99 4.96 5.65 o 5.04 5.87 5.51 3.77 Alkalinity. g 1.34 1.27 i 1.61 0.44 1.47 1.30 1.65 2.13 2.50 2.02 1.37 0.96 2.39 2.34 1.85 2.75 2.64 bo IO IO 7^ 7* b bl b g Sulphuric Acid. 080- 910' 9W 1 160' .138 .045 .094 .112 .076 123 .062 .086 .264 .086 .116 .044 .050 .048 .040 .038 .041 .032 .024 .048 .062 Iron. 'bo 3,000 1 18,600 59 g 30,600 34,950 42,500 27,400 co I 34,000 40,950 13,700 48,000 34,562 7,200 ! 28,750 27,300 75,000 : 4,614 1 6,125 4,456 2,625 5,250 Bacteria Per Cubic Centimeter. RESULTS OF ANALYSES. 301 Allegheny River at Etna. (Parts Per 100,000.) co to CO -^1 to o 1078 1129 954 983 1008 1036 1057 Cn co Serial Number. Av'gs, Aug. 2 " 16 July 6 Av'gs, June 7 " 21 Av'gs, May 3 " 10 " 17 " 24 " 31 6[ Jdy 1898. Mar. 22 1 Date of Collection. - v SI M V oco ).O9 0 : 06' SO' cn : - 02 .sl'gt ud'y Turbidity. to 00 .27 .30 c? to 0 .27 .32 CO to .27 .25 .35 .40 .32 Color. o to o o oo 1 .0130 .0104 .0084 .0124 .0121 .0088 .0080 .0240 .0120 .0078 .0062 0120' Albuminoid Ammonia, i .0036 .0044 0800' .0035 .0042 .0028 .0023 88888 -' IO 00 to to co re ao .0022 .0016 Free Ammonia. s 0 1 i .0000.0562 .0000.0450 .0000.0675 1 .0000.0750 .0000.0225 L I .0000.0300 .0000.0150 .0000.0255 .0000.0225 .0000.0225 .0000.0075 .0000.0300 .0000.0450 .0000.0375 1 I .0000.0525 Nitrites. Nitrates. tO co do 2 do fl SZ CO Al ri n 5'1 9'1 0.9 Chlorine. to 4- O C_> CAJ o< luj C_~) cjj >4-. CA Qi IO - to ' > CO _L OI to 00 o o to to to 4- o< ce cc Total. CO 'T' >-1 co - I 4^ © io OS to do Oa H < M I 1 K'j 1 1 o< 3'9 CO io 0.3 14.2 4.7 0.2 0.2 6.2 6.8 0.0 0.4 do Suspended. 4.6 4.6 L-i 3.0 CO IO CH O 3.3 2.4 3.2 3.4 3.8 3.7 4* Loss on Ignition. a 5.15 3.98 ic 3.90 3.38 IO co 2.90 2.84 3.24 2.90 2.80 3.11 JO Total Hardness. 3.93 4.86 3.00 CO eg 98'5 3.10 2.60 to bi to to to to to to 00 to 0 0 89'6 1.80 Alkalinity. >-4 i-1 1--4 O O 0 O 1 0 CO CO Cn 4- (Q 00 co do 0 1.49 l79 .38 '.52 .82 § 00 Sulphuric Acid. co .026 .020 .020 800' .002 .004 0 co .046 .035 .046 .028 .030 0 0 Iron. JO 139,000 59,000 O89' I >-1 65,800 16,400 O 6,900 7,700 40,400 17,300 10,4(X) 001'6 Bacteria Per Cubic Centimeter. EFFLUENT-ETNA CRIB. Samples of water, which had passed through this crib were collected once a week, during the months of August to November, inclusive, 1897, and then, once in two weeks until the close of the experiments. The samples were collected from a petcock upon the pump. 302 APPENDIX NO. 2. EtJInent-Etna Cril>. (Parts Per 100,000.) £ 475 498 528 547 - 72 C < 1 C C« - I c< 208 244 265 300 105 126 156 174 Serial Number. Av'gs, Dec. 14 " 28 Av'gs, Nov. 2 " 8 " 16 " 24 " 30 Av'gs, - - - 5 Av'gs, X e* IC IC ~ Av'gs, ~ Date of Collection. CO IC • V.sl'gt Slight Clear V.sl'gt Slight Clear Clear V.sl'gt V. " Clear Clear V. sl'gt V. " V. " Dec'd Clear Slight Turbidity. •p or or co .10 .20 .20 .20 .20 O O O O' ic io .20 .30 ic to ; ; ; Color. .0036 .0042 .0030 .0111 .0172 .0110 .0086 .0110 .0078 .0097 .0090 .0148 .0096 .0056 .0116 .0126 .0122 .0118 .0098 .0108 .0176 .0062 .0076 .0118 Albuminoid Ammonia. Nitrogen as, .0018 .0018 .0018 .0028 .0042 .0018 .0022 .0010 poo- .0018 .0018 .0010 .0014 .0019 .0018 .0018 .0014 .0026 .0018 .0028 .0016 .0020 .0010 Free Ammonia. 1 .0000.0862 _._L . irso-oi)(10' 0060',0000' .0000.0795 .0000.0300 .0000.0675 .0000.0975 .0000.0825 .0000.1200 §§§§ O' 74 O' 0 kilOOpOOO' .0000.0975 .0000.0900 .0000.0900 .0000.0900 jc .0000.0629 .0000.1350 .0000.1687 .0000.1313 Nitrites. Nitrates. 8.29 co 7.69 5.40 5.76 6.69 7.97 4^ O t6't jKSt 8Ct ort £ tc 4^ CO CO 7D ic GO p Iff eo't V9f 08't grt Chlorine. CO co Lu o o hi 33.2 24.8 31.6 34.0 22.0 24.0 24.8 29.6 77 16.0 17.8 21.8 24.0 IC 30.4 25.2 23.6 18.4 Total. Residue on Evapora- tion. 1 0.0 12.4 0.0 0.0 0.0 0.0 0.2 0.0 0.0 11.0 Suspended. 12.0 12.8 12.6 12.8 9.2 12.4 12.8 15.6 10.7 8.8 10.4 1 1.2 12.4 7.3 4.4 6.2 9.2 9.6 co 9.6 6.3 8.8 7.6 Loss on Ignition. - co c? co 7.78 9.03 10.19 ^4 7.94 7.26 7.03 8.02 8.02 7.62 9.48 7.50 7.50 1.0.94 10.60 12.46 10.90 9.81 Total Hardness. 8.34 7.67 । 9.01 7.70 7.32 6.79 8.35 9.08 X) 7.20 7.91 6.78 6.81 , 7.31 7.40 6.89 7.55 7.87 7.30 10.39 1 14.30 9.85 9.23 Alkalinity. IC 9ft srs 3.40 3.33 3.61 3.33 3.64 CO 3.13 2.71 2-99 |8.19 - 1.51 2.27 1.99 2.82 IC 2.27 2.51 2.20 1.95 Sulphuric Acid. .010 .015 CO .034 .046 .058 .026 .006 o .028 .018 .030 .026 .029 .022 .008 .046 .042 tS0' .150 .040 .010 .018 Iron. 2,000 • 2,000 698*8 g 13,965 JXJOJC^ Iclc^J O 0 S 0 ic Lt8*L 881 oot 885*1 914 528*1 5t9 Bacteria Per Cubic Centimeter. RESULTS OF ANALYSES. 303 Effluent-Etna Crib. (Parts Per 100.000.) Serial Number. Date of Collection. - Turbidity. Nitrogen as, Chlorine. Residue on Evapora- tion. Total Hardness. Alkalinity. Sulphuric Acid. Iron. Bacteria Per ; Cubic Centimeter. | Color. Albuminoid Ammonia. Free Ammonia. Nitrites. Nitrates. Total. Suspended. Loss on Ignition. 1898. 648 Jan. 11 Clear .05 .0064.0022.0000.1575 8.41 36.8 0.014.0 6.04 4.63 3.92.012 929 688 ** 2o .00 .0042.0014.0000.1275 6.59 31.2 0.012.0 8.17 7.93 3.19.010 155 Av'gs, .02 .01)5:' .0018 .0000.1425 7.50 34.0 0.0 13.0 7.10 6.28 3.55 .011 542 727 Feb. 7 Clear .15.0044.0028 .0000.1575 7.02 31.6 0.0 9.2 9.47 1 ' 1 8.053.23.018 300 766 *4 22 .17P.0O38.0O16.0000 1 1 1 7.20 30.0 0.0 8.0 8.24 7.01 3.16.010 225 Av'gs, .16 .0011 .0022.0000 .1575 7.11 30.8 0.0 8.6 8.85 7.53 3.19 .014 202 801 Mar. 8 V.sl'gt .17 .0036.0020.0000.0600 6.55 28.0 0.0 7.6 9.28 8.20 3.16.008 756 837 ■{ 22 Clear .15 .0062 .0014.00001.0565 Illi 5.72 25.2 0.0 9.2 8.62 7.22 .010 Av'gs, .16 .0049.0017.0000 .05826.13 26.6 0.0 8.4 8.95 7.71 3.16 .009 756 916Apr. 19 Clear .12 .0034.0020.0000.0300 4.76 ! ! i| 22.8 0.0 7.2 7.00 6.05 2.12 .010 825 955 May 3 Clear .15 .0036.0016.0000.0450 4.78 21.2 0.0 4.0 7.18 6.55 2.06.006 150 984 " 10 .20 .0038 .0040.0000.0225 5.08 23.2 0.0 4.4 9.42 6.95 2.28.008 250 1009 " 17 << . 15 .0028.0008.0000.0075 4.80 22.6 0.0 7.6 9.18 6.862.06.006 720 1037 " 24 < c .20 .0040.0022.0000.0375 3.91 21.6 0.0 7.4 9.80 6.75 1.72 .018 400 1058 " 31 I ( .10.0064.0018.0000.0375 4.62 20.5 0.0 6.0 8.40 6.321.47 .008 770 Av'gs, .16.0041 1 1 II .0021.0000.0300 4.64 Illi 21.8 0.0 5.9 8.80 6.691.92.009 460 1079 June 7 Clear .20 .0040 .0006 .0000.0300 5.15 19.2 0.0 4.8 6.98 6.15 1.85.003 5,200 1130 " 21 V.sl'gt .22.0030.0008 .0000.0225 4.80 23.8 0.0 7.2 7.90 7.421.68.008 325 Av'gs, .21.0035.0007 .0000.0262 4.97 21.5 0.0 6.0 7.44 6.781.76 .005 2,760 1178 July 6 V.sl'gt .20 .0058.0016.0000.0675 4.42 20.6 0.0 6.8 7.90 6.86 2.24.008 1,520 1227 " 19 Clear .20 .0054.0014.0000.0525 3.92 18.4 0.0 5.2 6.28 5.70 2.47 .014 9,350 Av'gs, .20.0056.0015.0000.0600 4.1719.5 0.0 6.0 7.09 6.28 2.35 .011. 5,450 304 APPENDIX NO. 2. Effluent-Hulton Crib. (Parts Per 100,000.) CO bC CO i Serial Number. 1891 Aug. Date of Collection. Slight Clear i Turbidity. bO bC O< Color. .0068 .0066 .0070 Albuminoid Ammonia. Nitro .0022 .0018 .0026 Free Ammonia. .0000 0000' 0000' Nitrites. .0487 .0450 .0525 Nitrates. 4.56 5.41 Chlorine. I< bC - Total. j. p to Suspended. ? § si 74 i>c 6.2 8.2 Loss on Ignition. > 0 1 10.30 05 iD 00 IO Total Hardness. 00 do io Alkalinity. '"75 CO 2.18 co eg Sulphuric Acid. 070' 810' 660 Iron. -I Tc £ u-1 £ £ Bacteria Per Cubic Centimeter. 1 etna tap. Samples of "Tap Water" supplied in Etna were collected once in two weeks, during months of October and November, 1897, then once a month until May, 1898, and then once in two weeks until the close of the experiments. The water is pumped directly into the system, the surplus passing into an elevated iron tank. The samples were obtained from a tap upon Bridge Street. Etna Tap. (Parts Per 100,000.) 989 659 94f 9 IF 998 Serial Number. Dec. 14 Av'gs, Nov. 8 " 24 Av'gs, 1897. Oct. 12 " 26 Date of Collection. V.sl'gt V.sl'gt Clear V.sl'gt Clear Turbidity. o g (V < )<-' 08' .20 .20 Color. .0054 0 & .0098 .0118 .0110 1 8 g Albuminoid Ammonia. Nitrogen as, .0016 .0027 .0036 .0018 .0015 88 l-l -1 IC X Free Ammonia. .0000 .0000 0000' 0000' 1 0000' 0000' Nitrites. SI s .0525 .0225 .0825 0 .0975 .0600 Nitrates. 097 p 99'9 49'9 4.96 4.82 5.11 Chlorine. t68 g 27.6 34.4 k. 22.4 27.6 Total. Residue on Evapora- tion. 0.0 0.0 0.0 Suspended. 13.2 11.5 9.8 13.2 10.6 871 0'01 Loss on Ignition. 8.17 8.35 7.86 8.84 7.15 7.25 7.06 Total Hardness. 71 a> o< 7.48 8.22 88'9 6.67 6.99 Alkalinity. 3.16 3.37 Ls 48'8 2.62 1.96 3.28 Sulphuric Acid. .030 b b IC S .019 080' isw ! Iron. IC 0 IC 98l'l 008 7 JC lc 2,450 22,140 Bacteria Per Cubic Centimeter. RESULTS OF ANALYSES. 305 Etna Tap. (Parts Per 100,000.) co to CO -J 4s. to 1179 1228 1131 926 1010 1059 877 802 728 649 Serial Number. lAug u Av' July June <AV Mav it C I Apr. Mar Feb. 189 Jan. Date of Collection. OQ CR OQ GO S to □D . So to 3 17 31 CH co ■■-4- - ■ ■ re <1 Q o Q lighl Hear sl'gi Hear sl'gi ight lear it co s lear lear lear Turbidity. io to io io io to O i-1 i-1 H-1 © Color. Ct -I o to © to ex 4 e *4 *sl Ox 8 w 300' 88 Ci Cl .003 1 .003 .003 .006 © .003 .004 8 o< Albuminoid Ammonia. CO GO CO to o 4s- 4* o 4^ 00 GO to GO Free Ammonia. .002 .001 .002 100 100 100 8 100 888 3 001 001 § w ex 4s as GO c< GO CO oo L 1.0000 i.0000 1 .0000 .0000 8 oooo- 0000' 0000' 0000- .0000 1 i i Nitrites. HEN AS o © .08 .06 ok to to .01 .01 .04 © Ox *4 to {Nitrates. Ci 25 4.86 00 5.32 V-t o to ez't k Ct ei^Cl ex Cx to to 2 60'9 g 2 4.24 5 4.54 0 3.94 184 |C O O O 4- 4- 4- bo co Ci co to 15.32 5 6.40 5 7.60 )8.10 Chlorine. tO Ci 25 27 O to CD O to to h-* tO tO OlCH te Ci to GO to Total. Mm ex to co bo *4^ io io © 4- © 4-** O co o © O o © © © © o © © Suspended. S t> ►-< ('■""'I lb o c" b bob b § td CO © -a Cl Oi Ci ~4 ex ex co GO GO © © Loss on Ignition. b © ' a Ox © © GO 2 CO Ci 4-* CD to to © © 4s. 4-- - co -I Ci *4 GO GO 00 -4 -I GO © o Total Hardness. io o io O GO to b do 4* io CO 8 to 4^ 4^ co O CO »-i o to o o IO o 00 o -4 o © CJ -4 Ci Ci Ci Ci © -I GO 4- Alkalinity. co *4 be CO Ci io O GO *4- io GO bo to IO 1-' GO Cl -4 CO 00 00 te Ci •-* to to bo co co to to 4^ M to io sr 1.8 2.0 1.4 to to o CO io CO Sulphuric Acid. to to to -4 Ci 00 - Ci GO to co GO o o 8 88 8 8 888 to 8 8 O Iron. । p- O CO © Ci Ci co Ci CO Os 4S- GO GO 00 to ■ - .. . u-I to Bacteria Per ^t'co Io 4^ IO i-1 co to CO Ci ex Cubic Centimeter. 8 50 50 © *4 Cl O Ci © © *1 ICC © O cn Ci Ci Ci to co © ALLEGHENY RIVER AT MILLVALE. Samples of the "Allegheny River at Millvale" were collected about once a week, from the middle of August to the last of October, 1897, and once in July, 1898. The supply of the borough of Millvale is ob- tained from the Allegheny River, about four miles below Brilliant upon the opposite side, from two cribs, one owned by the borough and one bv 306 APPENDIX NO. 2. the Bennett Water Company. The latter is ioo feet long, 16 feet wide, and 4 feet deep, and is built of 2-inch x 4-inch lumber in the usual crate style, and covered with stone, gravel, and sand. The crib is placed in the stream, where the current is swift, and the filling has been frequently washed away, necessitating frequent repairs. The average daily pump- age is given as about 550,000 gallons. Samples were obtained to deter- mine the efficiency of this crib, only. The river samples were collected from the bank near the pumping station, in the current of the river. Allegheny River at Millvale. (Parts Per 100,000.) to to O' 325 357 383 417 Q Q 04 to CO O' 157 182 Serial Number. 1898. July 19 Av'gs, Oct. 5 " 12 " 19 " 26 Av'gs, Sept. 7 " 13 " 21 " 28 Av'gs, 1897. Aug. 24 " 31 Date of Collection. 0.08 Slight V.sl'gt V. " Slight c 4 <4 V.sl'gt Dec'd Slight Turbidity. 03 o io .35 .30 .20 .20 to .30 .25 .25 .30 4^ o o: Color. .0110 04 0160 .0188 .0132 .0124 6SW .0166 .0204 .0146 .0122 9Z10- .0196 .0156 Albuminoid Ammonia. Nitrogen as, .0080 .0043 8888 Q W L C 4- XOXD .0043 .0022 .0074 .0046 .0030 .0016 .0018 .0014 Free Ammonia .0000 1 .0000 iill .0000 .0000 .0000 .0000 .0000 oooo- .0000 .0000 Nitrites. II '.0750 2.55 s cP .0975 .0675 .0675 .0450 .0581 o o o o CO O' Ci 03 K) to O O' 04 o 04 .0800 .0825 .0775 Nitrates. 3.25 2.75 3.29 3.18 3.78 to Ci 03 to co to to co h-* oo h-* CO CO O co s 1.61 2.19 Chlorine. bi 17.2 W H H b^CiX 14.5 o! Ci to tO 4^ O 4^ to 10.8 11.6 Total. Residue on Evapora- tion. > 2.0 4.0 1 Suspended. as 5.2 7.4 4.0 8.0 5.9 Cn 74 oo Cn CO o o to 4.0 4.4 Loss on Ignition. 4.92 5.41 4.98 5.20 5 87 5.60 6.62 5.80 9.27 7.20 4.21 to Ci 5.57 4.95 Total Hardness. 9ioU'gorf i 1 | 5.04 04 04 4^ 4^ CO 03 <1 bo HOCHtO 5.26 4^ Oi Ci 4^ O CO 03 CO 4^ ^1 03 O 4.41 3.98 4.85 Alkalinity. |2.46 2.40 2.33 2.71 2.41 1.71 1.23 1.27 1.58 2.78 b-1 00 4^ CO CD Sulphuric Acid. CH o o o o C;< tC 4- C 4- 00 4- C5 £ to o o o o Ci O' to to 4- 04 Ci 04 0S0' 1 .040 .060 Iron. 69,126 CD 4^ to 1-1 ^0^03 JO 'oi'o cd'o 88S8 3,762 JO^ 03 co'o'co co to 04 Q 04 O O 04 009^ 4,725 4,475 Bacteria Per Cubic Centimeter. EFFLUENT-BENNETT WATER CO. CRIB, MILLVALE. Samples of the water which had passed through this crib were col- lected once a week from the middle of August to December I, 1897, and, then, about once in two weeks until the close of the experiments. These samples were collected from a tap upon the pump. RESULTS OF ANALYSES. 307 Effluent-Bennett Water Co. Crib, at Millvale. (Parts Per 100,000.) Ci Cn - GO 4- Ci 441 477 495 526 544 326 358 384 416 216 229 263 296 127 158 183 Serial Numl ?er. stion. Av'gs, Dec. 14 " 28 Av'gs, Nov. 2 " 8 " 16 " 24 " 30 Av'gs; O tOHH Ci co to Cn Av'gs, Sept. 7 " 13 " 21 " 28 Av'gs, 1897. Aug. 18 " 24 " 30 Date of Collet Slight Clear V. sl'gt Slight Dec'd V. sl'gt Dec'd V. sl'gt V. " V. " Clear Slight V. " V. " Dec'd Slight ( c Turbidity. to o o to 00 .20 .30 .40 .30 .20 to o .30 .20 .15 .15 to o tO IO CO 4- Qi O O O 4- O : o: Color. .0053 .0064 .0042 .0148 .0064 .0080 .0280 .0126 .0188 o GO tO £ tO O Ci CO O .0132 .0164 .0136 .0116 .0112 Ci to o o p Ci Ci Qi h-1 GO Ci Albuminoid Ammonia. Nitrogen as, o o IO .0022 .0018 0200' 88888 to to to +. 4- X O4- .0022 8888 CO bC IO O GO O tO .0019 .0016 .0035 .0014 .0012 .0017 .0020 .0017 .0014 Free Ammonia. 1.0000 it 1.0000 .0000 '.0000 .0000 .0000 .0000 i lili .0000 llii .0000 .0000 .0000 .0000 Nitrites. >.0675 .0675 .0675 .0615 .0300 .0600 .0900 .0300 .0975 1 .0619 o o o o 4- Ci Q' CO Qi O to O OOCiO .0497 .0412 .0450 .0450 .0675 g .0600 .0750 .0900 Nitrates. 1.69 1.58 1.81 3.5S 6.78 5.77 2.43 1.63 1.31 3.29 2.12 3.46 3.38 4.22 tO CO 00 to CO tO p O tO CO CD Nmqch 1.50 1.28 1.32 1.91 Chlorine. to bi 32.4 10.8 23.0 27.8 25.6 30.8 12.0 18.6 18.8 N) H H >-- CO GO GO On bi b t to 14.2 p CH 4- p O to O Ci 10.9 CO 8 co 4^ O to Total. Residue on Evapora- tion. 11.3 to o to 4- to 4.4 0.0 । 0.2 .14.8 ' 0.2 7.0 . . co • • to_ Suspended. 92 14.0 4.4 to wooo Ci Ci O O Ci 7.7 5.47 6.0 5.31 7.6 5.16 6.0 5.48 11.2 5.92 5.4 6.50 Ci Ci CH 4- bobb bi 4- 4- Qi bo 4- to Loss on Ignition. i 5.94 । 9.08 > 7.06 ' 3.94 5.27 6.32 4.70 4.80 Total Hardness. 3.51 3.97 3.06 4.65 5.80 5.28 5.20 3.80 3.15 3.08 3.30 . 2.87 4.17 5.46 5.02 4.70 3.28 2.39 SI'S 5.28 4.63 5.05 5.63 5.12 5.11 5.94 5.62 3.81 4.44 4.70 4.08 4.55 Alkalinity. 1.23 1.75 1.95 2.92 3.02 1.65 1.44 0.72 2.53 2.51 2.47 2.51 2.64 1.72 1.26 1.23 1.65 2.75 1.11 4^ bi tO CH Sulphuric Acid. .047 .008 .086 .144 I-1 o w o o csco4O04 O 4- O CC Ci .033 coop WO4-W O CO CO O s GO .025 .020 .046 .060 .100 .160 .070 .070 Iron. 5,250 7,150 3,350 37,140 CO 4* to to oo'bo'cn o o o o o o o o o o> 41,669 6,450 18,725 71,500 70,000 4,144 5°^ 5^5° 'U* o'to'to to O CH o Gi O WC 7,533 pi^jio 4^ "to CO to 41 O C1QO Bacteria Per Cubic Centimeter. | APPENDIX NO. 2. 308 Effluent-Bennett Water Co. Crib, at Millvale. (Parts Per 100,000.) w to 03 -Q 1181 oo O i 4^ 878 913 803 838 729 767 646 685 Serial Number, Av'gs, Aug. 2 " 16 July 6 Av'gs, May 17 " 31 Av'gs, Apr. 5 " 19 Av'gs, Mar. 8 " 22 Av'gs, Feb. 7 11 22 ercT JO 1898. Jan. 11 " 25 Date of Collection. co co << CQ<! <5 co ight ( c ight id'y sl'gt sl'gt lear ud'y sl'gt light ight sl'gt Turbidity. bD 03 tO O OI to . - I 03 03 tO 4^ -<r o CO .17 .22 to to .20 .25 tO O 03 eg .30 .30 Color. .0107 .0094 .0120 .0110 .0189 .0310 .0068 .0062 .0068 .0056 .0093 .0046 .0140 o g .0062 .0038 .0084 .0082 .0086 Albuminoid Ammonia. a S © .0019 .0016 .0022 .0016 .0017 .0026 .0008 .0015 .0012 .0018 .0019 .0020 .0018 to .0026 .0022 ZI00' .0020 .0014 Free Ammonia. .0000 .0000 .0000 1 .0000 .0000 .0000 .0000 .0000 .0000 1 .0000 .0000 .0000 .0000 .0000 0000' .0000 .0000 Nitrites. K) O Cn o o OSZO' .0300 .0150 .0450 .0412 .0450 .0375 .0525 .0525 .0525 .1575 .1575 .1387 .1500 .1275 Nitrates. tO 03 CH 2.79 1.92 1.42 1.54 1.05 2.04 1.39 1.40 1.38 1.13 1.44 0.82 1.39 1.51 1.28 1.04 1.18 0.90 Chlorine 17.4 23.2 11.6 p 32.5 55.6 9.4 8.9 8.8 9.0 18.4 10.0 26.8 10.1 co o 14.6 to O0 O bo 4- Total. mW 5m 5.4 8.4 2.4 0.8 22.6 4^ O Cn O 03 p 0.0 0.2 bo C5 o p 0.0 0.3 03 bo 6.8 0.8 Suspended. SIDUE ON ^APORA- TION. 03 bo 5.0 2.6 3.8 3.7 4.0 3.4 3.0 2.8 3.2 4.6 3.6 5.6 4.2 5.2 3.2 j 4.2 5.6 2.8 Loss on Ignition. 4.69 5.85 3.54 3.35 3.22 3.52 2.92 2.82 2.88 2.77 3.96 4.68 3.24 3.60 4.08 3.12 2.92 2.98 2.86 Total Hardness. 3.96 CO 4- to J o to ors 2.70 2.70 2.70 2.36 to to CH I-1 GO 4- 2.70 tO 03 o 2.91 3.62 2.20 2.50 OS'S OZ'S Alkalinity. 1.47 1.34 1.61 0.92 0.99 1.16 0.82 0.59 0.27 0.92 1.27 1.27 ... 1.43 1.72 1.14 1.07 1.47 0.68 Sulphuric Acid. .010 900' HO' .020 .042 o o CO 4^ 00 05 .051 .058 .045 .106 .050 .162 .039 .046 .032 s .142 .046 Iron. 18,800 18,200 i 19,500 12,500 27,800 53,200 2,400 3,625 3,400 3,850 5,100 5,100 12,950 12,950 | 10,250 12,000 8,500 Bacteria Per Cubic Centimeter. RESULTS OF ANALYSES. 309 MILLVALE TAP. Samples of the "TapWater" supplied by the BennettWater Company in Millvale were collected about once a month during the work. The water is pumped directly into the service system, the surplus passing into an elevated tank. The collections were made from a tap near the railroad station. Millvale Tap. (Parts Per 100,000.) 1055 £ 839 768 c. 919 442 496 545 327 385 106 Serial Number. May 31 Apr. 19 22 Feb. 22 1898. Jan. 26 Dec. 28 Av'gs, Nov. 2 " 16 " 30 Av'gs, Oct. 5 " 19 1897. Aug. 11 Date of Collection. <2 <3 £ co < < . << ■ O sl'gt sl'gt nd'y sl'gt sl'gt : $ cc * * 7 sl'gt ec'd Turbidity. 05 to Oi .20 CO FC to .20 .40 .20 to to .30 .15 Color. §■ 1 0148 0044 0094 0054 0177 0108 0276 0146 0098 0098 0098 9020 Albuminoid Ammonia. Nitrogen as § 0200' .0020 .0024 .0012 .0020 .0018 .0016 .0026 .0012 .0012 .0012 .0012 9200' Free Ammonia. b i .0000 .0000 0000' .0000 .0000 .0000 .0000 .0000 .0000 .0000 .0000 .0000 '.0000 Nitrites. £ ■ g o co Ot 05' .1200 .0750 ,0675 .0225 .0750 .1050 .0787 .0975 .0600 .0740 Nitrates. o - o to CO tO Ci CO co to H-1 s to o o b> k-4 CO bi GO bl CD Ci CO GO Ci to O 0 CH .68 .42 CO Chlorine. -_1 to ►-1 . 1 I ' to - 4^ to to iO o o co GO 4^ 4- CO Ci - i bi to Total. >-i b 4-. Ci do 4G btb 4- Ci tO b j * > 1 o b b to p p Ci p to co 0.0 16.0 02 b Suspended. 3 0 3 • W M w GO 4^ b pl co to co Ci 4- 4^ 74 .0.8 7.2 5.2 Ci to 4 8 7.6 Ci io Loss on Ignition. > © to GO O 3.08 3.28 28'8 2.48 to Ci Z6f 5.82 5.61 3.48 5.30 5.30 5.31 6.10 Total Hardness. to CH 2.70 2.35 2.26 2.17 2.24 6FJ 5.48 4.85 3.14 5.00 5.17 4.84 7.10 Alkalinity. 0.79 0.92 0.99 0.96 0.65 00 bi p p to co bi 0 Ci 2.61 2.58 2.64 0.69 Sulphuric Acid. s s loot CO s X to .05 .56 .09 s .05 .00 to Ol Iron. GO o o o to 4- 4^ co ci >-A to p p co p co p.to p .©.jo Bacteria Per 870 775 850 820 125 588 640 625 500 710 301 120 142 Cubic Centimeter. 310 appendix no. 2. Millvale Tap. (Parts Per 100,000.) 1275 1336 1182 Serial Number. Av'ge, 9[ „ 6 'Sny 1898. July 6 Date of Collection. 1 Sligh u Sligh Turbidity. ert* 88' .27 .30 co o Color. o .0088 .0120 .0118 Albuminoid Ammonia. Nitroc bO I-I .0016 .0026 .0028 Free Ammonia. '.0000 .0000 .0000 .0000 Nitrites. 0090' .0600 .0600 8 Nitrates. io 2 66 1.88 1.72 Chlorine. 14.1 16 6 11.6 9.6 Total. mW lTj " 1.6 2.2 b Suspended. 5 > O • L J > O 3.6 4.6 2.6 Loss on Ignition. 4.69 5.88 3 50 3.48 Total Hardness. 3.89 4.70 3.08 3.35 Alkalinity. 1.33 1.50 1.16 0.96 Sulphuric Acid. .012 016 .008 .016 Iron. oc 09*9 01'os 09'Z Bacteria Per Cubic Centimeter. 7^ OHIO RIVER AT SEWICKEEY. Samples were collected of the "Ohio River at Sewickley," three times in the latter part of 1897 and once in June, 1898. The water supply of Sewickley is derived, during a portion of the year, when the water-shed will not furnish sufficient water, from cribs in the Ohio River near Osborne Station. There are two cribs, one built in 1893, which is 32 feet long and 16 feet wide, and another, built in 1894, which is 80 feet long and 16 feet wide. Both are of the usual crate construction with stone, gravel, and sand above and around them. The samples were collected out over the crib from a boat. Ohio River at Sewickley. (Parts Per 100,000.) 445 512 Serial Number. Av'gs, 1897. Nov. 3 " 22 Date of Collection. CQ ight cc Turbidity. io .15 .30 Color. .0160 .0110 .0210 Albuminoid Ammonia, .0020 1300' 9100' Free Ammonia. g 5 o Q 1 000( 000( Nitrites. o co .0750 .0525 Nitrates. 3.69 5.36 2.02 Chlorine. 30.1 to CO 00 +- do Total. l KJ W yl 0.2 15.2 Suspended. HDUJ ,fAP0l TION 11.3 13.0 9.6 Loss on Ignition. > o SI'S 6.13 4.14 Total Hardness. o 4.20 2.60 Alkalinity. CO co 5.33 1.34 Sulphuric Acid. .098 1 .046 .150 Iron. os 23,40 54,00 Bacteria Per Cubic Centimeter. o o 311 RESULTS OF ANALYSES. Ohio River at Sewickley. (Parts Per 100,000.) - Ox CH Serial Number. to ^-4 0 Q o cc Date of Collection. to qq tn' Turbidity. S- W io io Color. o Ox o g Albuminoid co Ammonia. 00 cS Nit 8 o Free o to Ammonia. is o o f-•; w § o Nitrites. % o o< CJ Nitrates. to ox to 4^ to io Chlorine. o CO co Total. b> io p o o Suspended. ►H S z o d • js a jjx. pl Loss on to Ignition. 3.21 Total Hardness. to co io to Alkalinity. co to bi J-1 Sulphuric Acid. o p Ox Iron. 4- GO co ox ■^1 Bacteria Per ox 4-" Cubic Centimeter. 8 1 8 EEFLUENT-SEWICKLEY CRIB. Samples were collected from the "Effluent'' from this crib, twice in November, 1897, and once in June, 1898. The samples were taken from a tap near the pump. Effluent-Sewickley Crib, (Parts Per 100,000.) 1153 446 513 Serial Number. I 1898. June 27 Av'gs, 1897. Nov. 3 " 22 Date of Collection. Slight Clear Slight Turbidity. 1 bO to i-1 o o Color. i - .0202 .0325 .0080 Albuminoid Ammonia. Nitkoc 8 .0016 .0018 .0014 Free Ammonia. § § IB Nitrites. m o o 5o 02 .0600 .1050 .1500 .0600 Nitrates. 2.78 3.04 3.74 2.34 Chlorine. 18.2 25.2 co to o Total. 5m II 05 o o o o Suspended. n > 3 O & 5.4 p 13.6 5.2 Loss on Ignition. 6.77 CD Ol p p I co O IO Total Hardness. 6.42 9.02 12.78 5.27 Alkalinity. 1.61 2.16 2.44 1.89 Sulphuric Acid. .012 .016 .004 .028 Iron. 14,100 5,205 910 9,500 Bacteria Per Cubic Centimeter. SEWICKLEY TAP. Samples were collected near the railroad station in Sewickley, of the "Tap Water'' twice in November and once in December, 1897. 312 APPENDIX NO. 2. Sewickley Tap. '(Parts Per 100,000.) CH (X Av'gs, 447 514 Serial Number. Dec. 14 1897. Nov. 3 " 22 Date of Collection. 1 Clear Slight Turbidity. io o to io o O CH Color. 8 Oi GO .0129 .0160 .0098 Albuminoid Ammonia. Nitrogen as. g .0010 0100' 0100' Free Ammonia. 1 .0000 .0000 .0000 Nitrites. S to o< .1350 .1875 .0825 Nitrates. 4.48 to GO 3.73 2.83 Chlorine. 19.6 25.8 to to CO GO OS O Total. Residue on Evapora- tion. CO GO p o c © o Suspended. CO bi 11.6 7.5 Loss on Ignition. 8.26 7.28 GO oo 13.01 8.76 Total Hard i Alkalinit less. 10.11 12.22 8.00 y. 2.13 2.25 1.82 2.68 Sulphuric Acid. .058 430 ggf'S 600' .004 994 .014 5,850 Iron. Bacteria Per Cubic Centimeter. TAP IN DEPARTMENT OF PUBLIC SAFETY BUILDING, before filtration. Samples were collected from a tap in this building, once a week from September to the last of November, 1897, and once during the months of December, 1897, and January and March, 1898. The water suppD for the building is passed through a pressure filter, in which sul- phate of alumina is added. These samples were collected from a special tap delivering water which had not passed through the filter. Tap in Department of Public Safety Building, before Filtration. (Parts Per 100,000.) 270 280 Serial Number. Av'ga, I 1897. Sept. 22 " 27 Date of Collection. Slight (( Turbidity. CO .40 .35 Color. .0117 .0130 .0104 Albuminoid Ammonia. Nitrogen as, 9100' .0022 .0010 Free Ammonia. 0000' .0000 .0000 Nitrites. .0637 .0525 .0750 Nitrates. CO to co (3.08 3.38 Chlorine. o 15.2 16.8 Total. Residue on Evapora- tion. Suspended. 5.0 04 4- O 4^ Loss on Ignition. IS'S OS'S IlfS Total Hardness. SI'S 5.48 4.79 Alkalinity. 2.13 1.68 2.58 Sulphuric Acid. .040 o o Cl Iron. i 2,401 I 182 4,620 Bacteria Per Cubic Centimeter. RESULTS OF ANALYSES. 313 Tap in Department of Public Safety Building, before Filtration. (Parts Per 100,000.) . 018 Ci 591 0 4-4- MOSW owe 314 340 371 401 Serial Number. Mar. 14 I 1898. Jan. 17 Dec. 20 Av'gs, Nov. 1 " 8 " 22 Av'gs, i 1897. II Oct. 4| V.sl'gt " 11V. " " 18 V. " ' " 25 V. " 1 Date of Colle Turbid it; 3tion. Slight ! Slight Slight V.sl'gt Slight f. to Cx co o g to o< bo io to O 04 o Ci io io bo bo 01 0 0 0 Color. .0060 .0090 .0078 .0115 bob tOHH O Cl o .0164 .0158 .0132 .0148 .0218 Albuminoid Ammonia. Nitbogen as, .0012 8 GO 8 on .0019 .0038 .0012 .0008 8 Cl 8888 tOHHO 4- GO Ci GO Free Ammonia. I .0000 i i ill I .0000 .0000 .0000 .0000 Nitrites. .0450 .0975 8 O< i co .0525 .0325 .0525 0 0 00 .0900 .0750 .0675 .0488 Nitrates. 1.36 2 4^ to Cl 44 b^b 00 I-1 WWWN 4- b -J b 00 H y? 0 Chlorine. GO z co bi bo 17.6 21.5 14.4 Cl 4- Ci Ci Ci Ci bo 4^ 0 bi Total. Residue on Evapora- tion. 0.4 to co bo i»OH Suspended. 2.4 ■ 91 io b Cl 7.2 8.4 4.2 Ci bo 8.0 5.6 7.2 4.4 Loss on Ignition. 3.10 bi to to £ 1 5.80 4.68 2.84 Ox Ci Ox Ox Ox Ox to bo 0 to 0 Total Hardness. to io to bi GO 4- to o 5.68 4.41 2.50 44 bi Cl 4.61 4.15 4.87 5.01 Alkalinity. 1.23 g 4^ ox 2.88 3.68 1.68 to bi 3.02 2.78 2.16 2.47 Sulphuric Acid. o to b o o So b CH Cl 000 -104- COW s 0000 4^ WOi Ci GO Ci 4^ Iron. 13,100 26,250 33,525 58,100 18,325 24,150 11,721 10,192 1,134 800 34,760 Bacteria Per Cubic Centimeter. TAP IN DEPARTMENT OF PUBLIC SAFETY BUILDING, AFTER FILTRATION. Samples were collected from a tap in the basement, supplied with filtered water, on the same days that samples were collected of the un- filtered water in the building. 314 APPENDIX NO. 2. Tap in Department of Public Safety Building, after Filtration. (Parts Per 100,000.) 811 662 592 431 463 511 315 341 372 402 271 281 Serial Number. Mar. 14 1898. Jan. 17 Dec. 20 Av'gs, Nov. 1 " 8 " 22 Av'gs, Oct. 4 " 11 " 18 " 25 Av'gs, 1897. Sept. 22 " 27 Date of Collection. V.sl'gt Slight Slight Clear c c (C Clear cc (I C ( Clear Slight Turbidity. u bO owo O' .20 .20 .10 .10 CI .10 .20 Color. .0054 o o oo o 0062 n - - O O bO .0141 bo 2 2 o o o o 1 .0099 .0116 .0082 Albuminoid Ammonia, Nitrogen as, 0000^100' .0022 .0018 .0020 .0040 .0014 .0006 .0017 © © © © © © o © IO _ M .0022.0000 .0030 .0014 Free Ammonia. .0000 .0000 0000' .0000 .0000 .0000 1 .0000 .0000 .0000 .0000 .0000 .0000 N itrites. .0525 .1050 .0750 .0650 .0600 .0525 .0825 .0562 4- O M Cl C OT w O © O © .0581 .0338 .0825 Nitrates. 1.34 1.22 1.34 3.22 3.68 4.05 1.93 3.05 2.72 2.91 3.29 3.30 2.96 2.82 3.11 Chlorine. co 10.8 10.6 bO 18.4 21.6 11.6 16.6 17.2 16.4 16.0 16.8 pl bo 15.4 15.0 Total. Residue on | Evapora- tion. p p p 0.0 0'0 00 00 Suspended. to pl pl 6.4 8.8 2.0 © to [M3 W CO b oo a t CO 5.2 4.6 i Loss on Ignition. 3.21 1.60 00 4.86 6.49 5.30 2.78 5.45 6.70 4.77 5.03 5.30 CI do o 6.14 5.64 Total Hardness. 2.16 -o 1.43 4.44 6.11 4.98 2.22 4.62 4.66 4.11 4.68 5.04 p 5.29 4.86 Alkalinity. 1.34 1.30 l-l 2.57 2.36 4.02 1.34 2.61 3.02 2.40 2.67 2.37 bC O 189 2.64 Sulphuric Acid. 810' 010 .068 013 .004 .006 .030 .014 o o o o o o OO X OI o S00- .004 .002 Iron. 910 [ 9,300 p © O O CQ 4° 0 CO M -.j - ■-* © © © 394 © 00 Bacteria Per Cubic Centimeter. WATER IN EXPERIMENTAL BOILERS. Samples of the water being evaporated in the experimental boilers were collected, about once a week during the months of June, July, and August, 1898. (See Chapter VI., Page 216.) RESULTS OF ANALYSES. 315 Water from Experimental Boilers. (Parts Per 100,000.) 1072 1073 1095 1096 1097 1101 1102 1103 1233 1116 1117 1118 1148 1149 1150 1232 1171 1172 1173 1195 1196 1197 1217 1218 1219 1244 1245 1246 1263 1264 1265 1295 1296 1297 1304 1305 1306 1323 1324 1325 1356 1357 1358 1368 1369 1370 1386 1387 1388 Serial Number. co to 44 co to 44 co to '-4 ^i to k-4 CO to 4 -ji to 4 CO to 44 to 4 CO to 4 CO to 4^ co to 4 CO CO to 4 CO to 4 CO CO to 4 CO to 44 co to Number of Boiler. June 6 " 6 " 13 " 13 " 13 " 14 " 14 " 14 " 19 " 20 " 20 " 20 " 27 " 27 " 27 " 28 July 5 " 5 " 5 " 11 " 11 " 11 " 18 " 18 " 18 " 25 25 " 25 Aug. 1 " 1 " 1 " 8 " 8 " 8 " 10 " 10 " 10 " 15 " 15 " 15 " 22 " 22 " 22 " 25 " 25 " 25 " 29 " 29 " 29 Date of Collection. 189 158 205 201 129 100 106 100 210 208 208 194 210 208 208 208 208 210 208 208 205 210 210 210 208 210 210 210 210 210 210 210 210 210 210 210 210 210 212 212 212 Temperature. Degrees F. 14.00 1.60 1.30 2.00 0.70 0.60 2.00 0.20 0.20 0.30 0.30 0.27 0.20 0.30 0.27 3.00 0.40 0.70 0.65 1.00 0.28 2.80 2.10 0.80 0.65 2.80 1.90 2.00 3.10 0.90 1.20 2.10 1.40 1.25 0.90 2.40 2.20 3.10 1.90 2.10 3.80 2.10 2.80 3.60 1.00 0.90 1.90 1.40 1.10 Color. 2.35 2.32 30.54 5.84 4.10 : 26.52 24.22 ! 25.43 46.10 16.50 5.00 17.22 48.84 18.09 43.11 20.40 72.10 46.85 17.58 86.94 83.30 29.90 21.20 132.70 119.00 182.50 187.06 34.40 195.68 248.86 143.44 164.88 212.20 218.60 136.25 238.50 118.00 30.08 41.12 30.04 70.40 57.04 58.20 58.96 72.80 53.28 11.92 10.30 5.32 Chlorine. Ci C > Ct 44 Ci Ci tC IC 4 4 ti 44 tO • 44 4444 . 44 44 i-i :::::::::: to to co ci co co ox co as o co 44 co 0 ; 0 ci ot 0 oc co • 0 0 0 to to co : : : : : : : : : : oo^ppppptowwMptopp; p p ci p p p. to p p p p p p p • • •' • • • • • ■ • ci 44 A 0 0 to ci to to co 44 co co • to to io 01 to co • 0 ci 00 to co co 44 ci Total. -1 v-i -1 CC :::::::::: ppppppppp joppppp; pppppp. pppppppp • • • • • : : ' Cl to to 4.7 00 44 to 44 CO 44 t© CO 00 to tO : O 0 io 44 0 O • 44 44 00 Cl 44 0 0 co Suspended. 0 o sc d w M O H'bO44 4* kMO ti ti H 41QOCI W® W ti IO® ® tO W WW tOH ti ti CO 41 H W ti ti to to 1-' to 1-' 1-* 44 44 pp44pppppppppCip4-'CnpppO®Q-4®4"atOO^WOlOlOpjaOpH1 p cn 44 co -4 -<t 44 ox 44 to to 4- CO io 4.1 -44 0 4- O O O CO CO IO 4- io io O Cl' Cl IC 31 44 4- Cl O O O O io CO Cl 4- O IO 4- C14- k-1 4- 4-. O --.t CO CO 44 co 4- 4- Loss on Ignition. k-- 44 q, qj, 4- to) oi to tO Ci -1 44 4- Ci Cl 4- 4- 4- 4- tO Ci 44 Ci Ci 4^ to; qt tO to 44 to to - tO tO 44 to Ci - k-i 4-1 p p p p p p p p p p p p p p Ci p p p p p p p p p p p 44 p p p JO O p p p JO p p p p to p p p p p 44 p p H-'t044C0t0t044C000 4-'t0H-'CnO00 00 44Clt04444^r^<joc0C0-<lOC3OC0C0C1 44 44.OC0C04-'j0t0H-'C000C0COQ0Ut4-' CO O to to 44 O O Cl O Cl CO ® O CO 00 to 4- O O O to to O O O O O O to 00 00 to O O CO O to - I CO 44 O <Z> CO O O O O CH 44 Total Hardness. 4.4ptopp4pp<ippHp[i4W®sppaaoo©p»wapp<ippp©W5pW4ap44WWCTwH cioci44ci-<rci>-'coi-'cocDciH4 0 44 4-'k-4cocotoacooi-'-<rcnj©t-'cocDOtoH-"o^itoai>-'bt4.H©fflM(»bboo C0OOOO4OO4O401HtiCt(»Ot0OtCOOClOWOOOa>C001OOO©C0OtC00O<3iOOCntCO0'00O Alkalinity. 4 4 4 4' w to 4'4-' 4-1 tO tO 4 tO tO tO 44 [|4ppp4Wp4pW44p©[f4pp<ipp4lpp<t<Ip<Ip<IptCp4<lW<ipp<ItOpp4ptCWpptO t0 44CDi0t0 44ClClC0Cn44C0 44OC0O~'4-icii044i0Csc0C044C0cDc©C0ic>C0c0Clc0bt44C1 44 00 C0t0 44btOCnC000O , ©4tO&05 4jM4W.0 4OT4-4C©<»44 4(»<I©0 4N4tt001©©©®4©014©OC0 0 4a>COC0 0104-Otai ! Sulphuric Acid. oooopooooooooaoooooooooooocooooopoooooooooooooooo OaOOCOOOOOOOOOOOOOOOOOOOOO44OOOOOOOOOOOOOOOO4i44OOC0O 44HH4Ht0tiN4444H4444HH4444H4©tCI4444H4W00t{tC44t04(X><»O®©l-'O0s 1 Iron. 316 APPENDIX NO. 2. DRIVEN WELL AT BRILLIANT. Samples from the "Driven Well" at Brilliant were collected during May and June, 1897. (See Appendix No. 5, Page 360.) Driven Well at Brilliant. (Parts Per 100,000.) o co 00 IC Serial Number. Av'gs, - s' o O CO Av'gs, 2 5 a cd W IO K> tO 71 h-* 00 Cl 4^ Date of Collection. Dec'd Mud'y u Turbidity. : : : : Color. .0025 .0020 .0030 .0067 .0120 .0030 .0050 Albuminoid Ammonia. Nitrogen as, CH 0850 .1060 .0062 .0093 .0027 .0066 Free Ammonia. Nitrites. Nitrates. ran 117.8 173.6 io 4.S 5.7 11.0 Chlorine. 8'Z6S 23>.O ... 349.6 ... 1 1 co 00 4- co co to I-* 4- 4- CO b do b *- Total. Suspended. Residue on Evapora- tion. to 00 128.4 27.6 9.4 11.8 9.2 7.3 9.4 Loss on Ignition. 35.3 32.0 38.7 s 17.7 15.0 17.2 14.5 Total Hardness. Alkalinity. 0.0 b : J- 2.6 1.3 0.3 0.1 Sulphuric Acid. .000 .000 .000 §§§? Iron. 121 143 <x a ei 4^ o co to Depth of Well in Feet. HOWE SPRING. Samples of water from this well-known spring, which is used largely by householders in the East End, were collected frequently during the months of August, September, and October, 1897, and once in May, 1898. RESULTS OE ANALYSES. 317 Howe Spring. (Parts Per 100,000.) 9001 399 to bo CO CO CD O CD Koco to GO - J Serial Number. O GO !> . <5 00 CO ■ 9° co to OT cro* tn !pC 3 " 13 " 27 3° L897. ug. 5 " 12 " 18 Date of Collection. Clear Clear Clear H < I Clear I« u Turbidity. o 8 8 888 Color. .0018 .0048 i go 8 §8 CH CR CO to o o j.0028 .0026 .0040 .0018 Albuminoid Ammonia. .0004 1 .0012 .0009 .0016 .0010 .0012 Tr. .0009 .0016 Free Ammonia. W O .0000 .0000 .0000 § o I o § i 0001 0000 0000 Nitrites. w o t-k >-k » J-k H* ua >-k .0150 2375 6375 .8000 5750 5375 .2027 .0375 .2580 3125 Nitrates. 2.50 1.90 1.92 1.86 1.75 2.15 1.77 1 ,1.79 11.77 [1.75 Chlorine. 4^ CO CD CO CD 38 39 38 CO GO 38 36 40 Total. to o GO 4^ 00 b< 4- GC CO > 2 O Suspended. Sag o • W M ■ 1 H M to 1 ~* Loss on Ignition. CH o 8.2 CD 00 GO O 4^ O G.O O o do Cl o w "!■ o 2 28.05 bO to 22.46 to to - CR 4- C: CD O O GO to to CO 19.06 17.27 30.05 Total Hardness. to co CD GO 23.11 28.44 28.62 28.87 27.83 4^ >-i bO 47.78 47.55 28.92 Alkalinity. GO GO 0.92 1.53 4^ tO CD co o 1.63 bl C3 C3 CO 00 ^-1 Sulphuric Acid. o .010 8 00 .008 .002 .014 .011 .008 .016 .008 Iron. * Bacteria Per tO 4^ 4- 16 76 Cubic Centimeter. o o : 4^ • • * Collected August 25, 1897. WERE AT McCONWAY-TOREEY MANUFACTURING CO. Samples were collected, twice in November and once in December, 1897, of the water obtained at this well; in order to ascertain the character of the ground water to be found in this vicinity, along the bank of the Allegheny River. The well is cased, is six feet in diameter and forty-five feet deep. The samples were collected from a tap near the pump. 318 appendix no. 2. Well at McConway-Torley Manufacturing Co. (Parts Per 100,000.) 564 Oi 4^ c: o Serial Number. Dec. 00* 189/ Nov. C 4 Date of Collection. to to co g o' so Cleai Sligh Turbidity. bO O Cn Color. o O o Albuminoid s OD bO • Ammonia. Nit o o Free bC CX oo Ammonia. w o 0000' .0000 .0000 .0000 Nitrites. CH • s Nitrates. o o w 3.09 3.0 3.1 Chlorine. o GO - 28.8 tv* j 0'0< !2.0 !8.0 Total. Wk 0.0 p 0.2 0.0 Suspended. DUE ON LPORA- ION. 10.4 11.6 12.8 10.4 Loss on Ignition. - r-l -1 r-1 5.61 Iff 6.03 4.80 Total Hardness. h-1 f-1 -' o s 5.20 3.13 Alkalinity. 1.89 2.18 2.23 2.13 Sulphuric Acid. § 600' .002 .002 Iron. Bacteria Per 494 494 Cubic Centimeter. ; WELL AT SLIGO MILLS. Samples of the water, obtained from a well located at this mill, were collected occasionally during July and August, 1897, and in June, 1898. Well at Sligo Mills. (Parts Per 100,000.) o GO oo 00 Serial Number. 1898 June Aug. 1897 July Date of Collection. Cn o-T Clear V.sl'gt Slight Turbidity. o 01 Color. .0036 .0056 .0110 Albuminoid Ammonia. .0008 .0046 '.0230 Free Ammonia. " ■ o 9010 0025 0040 Nitrites. w % ► .0225 .4559 0000' Nitrates. 7.80 IO GO o< 1.84 Chlorine. 84.5 58.4 30.6 Total. Residue on Evapora- © o o Suspended. o 23.4 12.9 GO Loss on Ignition. 11'- 08'8 o 4^ Total Hardness. © CO g O1 CR 00'0 Alkalinity. 25.90 15.15 4.71 Sulphuric Acid. TOO' .040 .140 Iron. N) Bacteria Per co Cubic Centimeter. o MISCELLANEOUS CITY SAMPLES. The following samples were collected during September, 1897, from various wells, springs, and taps in the 21st Ward, at the time when typhoid fever was abundant. RESULTS OF ANALYSES. 319 Miscellaneous City Samples,-Twenty-first Ward. (Parts Per 100,000.) o Dairy-Spri 9 •idQS tOS Tap on Shetla to cc Negley Rui 195 Larimer Avei 00 Dairy- ID co GO Tap on Thon CO Tap on Larin 166 Tap on Frank. Serial Number. GO CD r-t- co CD u C5 Sept. 2 co CD r~t- GQ (D H ce CD ft- lb97. Aug. 28 Date of Collection. Dec'd Clear Clear | Dec'd Clear Clear Dl^IS V. sl'gt Turbidity. .45 to o o .30 b o CO o .40 8 Color. .0078 .0060 zow i; O o o O DS00' o 95 W .0180 Albuminoid Ammonia. Nitrogen as, 8 00 I s 8 to 8 to .0009 00 Free Ammonia. 8 8 i 2 b § b 8 b § o o Nitrites. Ci 1 4.1250 3.0'00 1 4.5000 § Oi o .0675 o CH o Nitrates. co CH ng Water. o o md Avenue. 3.29 % Spring. we Spring. SO'Z ll Water. h-* to ipson Street. do wr Avenue. 1.85 itown Avenue. Chlorine. cc io 48.4 CO O 42.2 co co o 10.4 to o to Total. Residue on Evapora- g TION. £ 20.2 Suspended. 18.4jl0.85 32.6 13.35 20.8 9.94 12.4 5.68 GO o to OZ'^ 3.2 4.92 Loss on Ignition. Total Hard 12.87 6.29 5.55 4.08 1 to co g 9Vf 3.24 Alkalinity. 1.23 2.61 2.02 1.96 2.95 co 1.13 co Sulphuric Acid. .019 .014 too- to co .010 O co .018 090' Iron. 1,848 1,000 3,000 ! 14,700 1,500 130 Bacteria Per Cubic Centimeter. 320 APPENDIX NO. 2. The following samples were collected at various times of certain wells, springs, and streams, at the time of a typhoid fever epidemic in Turtle Creek. Also a few samples at Kittanning, when typhiod was unusually prevalent there. MISCELLANEOUS SUBURBAN SAMPLES. Miscellaneous Suburban Samples. (Parts Per 100,000.) Serial Number. / Date of Collection. Turbidity. Color. Nitrogen as, Chlorine. Residue on Evapora- tion. Total Hardness. Alkalinity. Sulphuric Acid. Iron. Bacteria Per Cubic Centimeter. Albuminoid Ammonia. Free Ammonia. Nitrites. Nitrates. Total. Suspended. Loss on Ignition. Seger's Well at Turtle Creek. 1897. 139 Aug. 20 V.sl'gt .0085 .0020 .0000 1.3500 2.56 36.8 17.4 14.42 11.68 4.20 .120 1,650 Knabe Well at Turtle Creek. 140 Aug. 20 Clear .0185 .0075 .0000 .0000 6.29 71.8 37.0 18.37 11.847.98 .016 3,800 Glunt Spring at Turtle Creek. 141 Aug. 20 Clear .0155 .0019 .0001 0.90 46.4 1.6 12*4 21.98 23.10 7.32 .100 1,400 Thompson's Run at Turtle Creek. 197 Sept. 2 .40 .1040 .0012 .0000 .1575 1.36 140.0 6.4 39.0 2.92 62.16 .284 3,825 Turtle Creek at Turtle Creek. 136 Aug. 20 Dec'd .1216 .0016 .0001 .3750 2.35 129.4 4.6 26.0 0.80 61.75 .060 896 138 " 20 Slight .0916 .0018 .0000 .3000 2.45 134.0 1.6 24.4 0.87 67.18 .075 353 198 Sept. 2 Dec'd .40 .0980 .0016 .0000 .1650 2.24 114.8 0.4 18.4 3.04 0.62 56.62 .102 28,000 Monongahela River at Mouth of Turtle Creek, 137 Aug. 20 Dec'd .0290 .0069 .0000 .3188 0.45 15.2 5.8 2.4 6.02 1.60 3.23 .400 2,925 196 Sept. 2 Slight .15 .0144 .0048 .0000 .1500 0.79 14.8 3.2 7.05 1.38 3.40 .040 5,225 Monongahela River at Mouth of Beck's Run. 185 Sept. 1 Slight .45 .0146 .0109 .0000 .0900 0.75 11.6 2.4 2.0 4.54 1.53,3.88 .060 23,250 RESULTS OF ANALYSES. 321 Miscellaneous Suburban Samples- Continued. (Parts Per 100,000.) Serial Number. Date of Collection. Turbidity. Nitrogen as, Chlorine. Residue on Evapora- tion. Total Hardness. Alkalinity. Sulphuric Acid. 6 Bacteria Per Cubic Centimeter. Color. Albuminoid Ammonia. Free Ammonia. Nitrites. Nitrates. Total. Suspended. Loss on Ignition. Allegheny River at Kittanning. 1 1898. 711'Feb.' 4 Slight .3d .0110 .0016 .0000 .1500 1.38 8.8 0.2 2.8 3.42 2.46|o.82 .164 Reservoir in Kittanning. 712 Feb. 3 Slight .30 1 .0098.0020 .0000 .1575 2.20 8.8 0.0 1.6 3.16 1 2.10|1.96 .056 j 2,100 Tap in Kittanning. 713 Feb. 3 Slight .25 .0096.0024.0000 .1650 1.84 9.6 0.3 3.2 3.82 2.303.23 .034 3,050 INDIAN CREEK AND VICINITY. Samples were collected, during the autumn of 1898, from Indian Creek, and some of its tributaries; from the Youghiogheny River, and from some of its tributaries, in the vicinity of Indian Creek. Indian Creek. (Parts Per 100,000.) bO bO bDO O co Serial Number. Av'gs, 1898. July 13 " 18 Date of Collection. V.sl'gt Slight Turbidity. CO .10 .17 Color. .0088 8800' Albuminoid Ammonia. .0016 .0016 free Ammonia. S o 8 8 .0000 Nitrites. Q S Z o o . C> 0090' Nitrates. 0.38 0.42 Chlorine. ic 4.2 10.2 Total. in re 0'0 Suspended. o O C r4 1.8 1.7 Loss on Ignition. > o • z 2.62 2.96 2.28 Total Hardness. 2.45 2.86 2.04 Alkalinity. 0.20 0.24 0.17 Sulphuric Acid. .020 .006 .034 Iron. 450 450 Bacteria Per Cubic Centimeter. 322 APPENDIX NO. 2. Indian Creek. (Parts Per 100,000.) 1269 1331 1354 1372 1390 1204 1221 1392 1395 1401 1405 1416 CO CO CO CO tO 00 CH co o O CO o GO Serial Number. Av'gs, Aug. 1 " 15 " 19 " 25 " 31 Av'gs, - 2 CD 00 Av'gs, Sept. 1 " 5 " 12 " 18 " 26 Av'gs, „ „ .. ! " " - g za to >-1 9° 4- ct CD CT >-> Date of Collection. Q® CO oa<? co i» FO & Clear Dec'd V. sl'gt Slight V. sl'gt Clear 6 I Clear Dec'd 1.50 Dec'd Clear Turbidity. to to to bo to to -A O O O < O io CO .20 .27 to .10 .20 .10 .10 .10 .19 .10 .15 .30 .30 .10 Color. .0140 .0072 .0140 .0380 .0068 .0038 .0190 .0190 .0052 .0040 .0042 .0048 .0054 .0074 .0164 .0070 .0220 .0410 .0080 .0042 Albuminoid Ammonia. .0019 .0024 .0014 .0034 .0008 .0016 .0014 £ ' b 2 o Looio .0038 .0050 .0044 .0088 .0021 o o o o o o o o o o I-4 h-4 CO tO tO O tO bO bD bO Free Ammonia. 3 w o o .0000 .0000 .0000 .0000 .0000 .0000 0000' .0000 o o o o o o o o o o o o o c o oo b o o .0000 .0000 .0000 .0000 .0000 .0000 Nitrites. Q W % s CH 0910' m0' 00S0' 0090' 0090' s 8 .0600 Mill .0525 o o o o o I G । C ' 1 O O QI O ' O O' .0315 O OOQO H4 bD O1 CH Oi Oi to to to O Ot cn O< Nitrates. J" 0.60 CCppH CT 4^ 4* CT b 00 to O 00 CO bo 0.32 0.32 §5 0.42 0.48 0.44 0.45 0.30 0.42 -<I 4^ CT CD 0 0 0 0 4- Chlorine. x> GO CO ^4 * J Oi p o to O.fe 52.1 8 * bO O 3.4 co co co co co O bo 4^ GO bl h 00 WCCQO ic b b Q i-1 Total. Ke E- CT 1.8 1.6 79.6 0.5 0.0 47.1 y to o 0.0 o o o o o b b b isc b 17.9 O ® H O H Suspended. H ™ > £ Z O 2 to 0.8 1.8 3.0 2.2 2.0| 2.1 1.8 2.4 to co to to CT L6 tO I-4 tO p to o b ic a Loss on Ignition. • H >• o 1.84 2.14 1.68 1.48 1.70 2.20 2.62 2.90 2.34 i 1.96 p p H H M b b co io O CO CD 4- CO ! 1.53 to p to to bl GO bl GO to GC O CO Total Hardness. 1.98 H-i 1- 1-1 CO to ct 4»- ct P o to o o o 2.37 to to O b- 1.89 HbOHHH co o io CO OOCIOO 1.66 2.28 1.82 0.80 1.20 2.22 Alkalinity. iro o o co o o bD 4^ 4^ OO O 0.09 0.00 0.19 0.00 o o o o o b b b b b o o o o o .0.23 o o o o o o b ct o 4^ CO 00 I-1 Cl Sulphuric Acid. .010 22882 to o ct oo 4^ .015 .004 .026 .004 .014 .001 .001 .001 .001 o O CT 4^ to CT Iron. 3,980 086*8 13,600 009'SI 1,350 1,350 3,300 oos's Bacteria Per Cubic Centimeter. RESULTS OF ANALYSES. 323 Mill Run. (Parts Per 100,000.) 4- 4^ 03 O O WOO Castleman's River. 1400 1408 1411 Laurel Hui Creek. 1394 Resler's Run. | 1898. 1355Aug. 20 Spring at Head of Pike Run. Av'gs, 1393iSept. 1 1396 " 5 1402 " 12 1406 " 19 1407 " 19 1414 " 25 1415' " 26 Serial Number. Av'gs, Sept. 12 " 18 " 26 Av'gs, Sept. 12 " 18 " 26 Sept. 1 Date of Collection. 1 Clear u CC Clear Ct V. sl'gt Clear .10 .18 V. sl'gt Slight Clear CC Turbidity. ... .5 tO tO o o o P to 'to o o o to .17 .27 .20 .20 .10 .10 .20 Color. .0069 .0068 .0070 .0070 9900' .0060 .0062 .0072 8 o .0100 8 .0034.0016 .0054.0036 .0040.0050 .0060,0050 .0058.0062 . ,0028i.0060 .0058.0054 Albuminoid Ammonia. Nitrogen as, : ' .0055 .0032 .0078 .0054 .0039 .0032 .0038 .0048 .0008.0000 .0030 Free Ammonia. .0000.0750 0000' oooo- 0000' b 8 .0000 .0000 .0000 .0000 .0000.0621 b b b b b b b 8888888 o o o o o o o b b b b b b b '■1 Q C. C. -1 CH -4 CI -4 -4 -4 Ci o c o oi oi oi o Nitrites. bob g g g .0675 .0525 .0750 .0750 .0180 .0225 Nitrates. 0.46 ppp tO Cl b 00 o O 0.39 0.60 0.30 0.28 0.60 0.42 0.43 poppppp P P to co b P ci o to co o to os to Chlorine. po o b 5.7 0.0 9.8 0 0 9.6 00 1 3.5 WWW bow to bo 2.0 3.4 4^ tO tO 03 CO p 03 b 4^ b 00 to b Total. Residue on Evapora- tion. o o o b b b 0.0 0.1 o o o o o o o b b b b b 4- b Suspended. 3.3 co to to b b 1.4 2.0 1.1 1.2 1.6 0.5 1.3 tOHOHHHH b to do b P b P Loss on Ignition. 3.03 1.34 2.88 4.86 2.12 2.00 2.38 1.98 0.90 0.80 CO to p p to to to JO bi co w w h b C: 4- O O to O O Total Hardness. s 1.30 1.92 1.38 2.07 1.90 2.40 1.90 0.840.00 0.82 to O P J.O to JO J-1 b -i to io 1 b CO O CO 00 o to o Alkalinity. 2.39.001 1.54 2.51 3.13 0.00 0.00 0.00 0.00 0.04 0.00 o o o o o o o b b b b b b b o o o o o o o Sulphuric Acid. b b b TOO' TOO- T00- TOO- .008 .002 SOO- ,010 .001 .001 .001 .000 .001 .001 Iron. 650 385 1,190 1,200 1,175 Bacteria Per Cubic Centimeter. 324 APPENDIX NO. 2. Youghiogheny River. (Parts Per 100,000.) to S Serial Number. Av'gs, Sept. 18 " 26 Date of Collection. Clear V.sl'gt Turbidity. Or .10 .20 Color. .0128 .0088 .0168 Albuminoid Ammonia. Nitrogen as, .0062 .0064 .0060 Free Ammonia. .0000 .0000 .0000 Nitrites. .0975 .0975 .0975 Nitrates. p 03 Cn o p co 4- Chlorine. 5.2 [ 2.8 Total. Residue on Evapora- tion. 0.0 0.0 0.0 Suspended. 2.0 1.6 Loss on Ignition. do o 2.12 1.48 Total Hardness. 1.76 -1 bO o CH CO Alkalinity. 0.00 0.00 0.00 Sulphuric Acid. .001 .091 .001 Iron. Bacteria Per Cubic Centimeter. REPORr UPON Bacteriological Investigations OF Fifteen Samples of Pittsburgh City Water, BY EUGENE WASDIN, M. D. Past Assistant Surgeon, United States Marine Hospital Service. APPENDIX No. 3. APPENDIX No. 3. Mr. Morris Knowles, Resident Engineer, Pittsburgh Filtration Commission. Sir :- I beg to report that acting in deference to the wishes of Chancellor W. J. Holland, Chairman of the Committee on Water Analysis, I started, on the 19th of March last, to analyze samples of the water supplied to the city, for the purpose of isolating any bacteria that might be injurious to health; or which would tend, by their presence in this water, to show that the city water supply is much polluted, and that upon this pollution depends much of the prevailing typhoid fever. By courtesy I have worked in the bacteriological laboratory of the Bureau of Health, and wish to express my gratification and thanks for the many and graceful courtesies received at the hands of those officials with whom I have been thrown. Of the fifteen samples analyzed, three, Nos. 7, 8, and 9, were especially examined with the object of isolating the bacillus of typhoid fever. Measured portions of these samples were seeded on Elsner's gelatine, a medium vaunted to eliminate all bacterial growths save that of the Bacillus typhi abdominalis and Bacillus eoli communis. Although a large number of organisms were studied carefully, none reacted to the Widal- Pfeiffer blood test as does the Bacillus typhi, although in other character- istics they were closely allied to these organisms. Also portions of other samples were grown on Parietti bouillon, a very acid carbolized medium, and these growths were examined culturally and under the microscope, but the Bacillus typhi abdominalis was not found. One element of trouble has been caused by having the gelatine melt during the warm weather. In making analyses of the other twelve samples, I have followed the well-known method of Theobald Smith, modified by the method of Hazen and White, i. e., a measured portion is planted on sugar bouillon and submitted to an incubator temperature of 41 °C. to 42°C. for from 24 to 48 hours. It is known that at this temperature, many of the com- mon water bacteria are destroyed, and that the intestinal forms survive. These intestinal (suspicious) organisms, in growing, disintegrate the sugar in the bouillon, and the liquid is said to ferment. The gas from this fer- mentation collects in the appropriate portion of the testing tube, and is itself studied. Usually, the fermentation of the sugar bouillon gives rise APPENDIX NO. 3. 328 to carbon dioxide (CO2) and hydrogen gas (H), so the gas formulae show- only the relative amounts of CO2 and H. Theobald Smith says that if water analyzed in this way ferments the bouillon, and especially if there is free evolution of gas, we may suspect that the water is contaminated by sewage. In fact he declares that, when the species which develop in fermentation solutions, seeded with such water, are transplanted to differ- ent media and studied, it is unusual to find bacteria other than the Bacillus coli communis, Bacillus enteritidis, Bacillus lactis oerogenes, and possibly Bacillus typhi abdominalis. I do not believe that the last named organism will be isolated in this way, save in a rare instance when it alone is present in the sample seeded. In all, ninety-three different organisms have been isolated and studied, both culturally and microscopically. Of these, fifty- three correspond to the organisms of the colon groups, one being Bacillus entcritidis and four Bacillus lactis cerogencs. Several were like typhoid, one especially, but did not react with typhoid blood. Thirty-eight were of the proteus groups, the ordinary organisms of putrefaction. The re- mainder were of little interest. The significance of these two groups is evident. A water contamin- ated with those of the colon groups must be considered unfit to drink ; for the probable presence of the typhoid germ, if there arise an epidemic of typhoid fever on the water-shed, is evident. The presence of the proteus organism in such quantity indicates much waste albuminoid material sup- plying their food; at the same time disease may arise from their presence in the body. In conclusion, I find every sample of water contaminated and giving rise to fermentation. From all but three samples fermentation germs were isolated. In these three it is hard to explain why the ferment was not found. However, it is well-known that many organisms growing together give rise to peculiar conditions not found in any single growth, a peculiarity of symbiosis not readily explained. Appended,* there is a tabulation of the work and results secured in the analysis of each of the fifteen samples of water examined. The source of each sample is shown, also the time of its collection ; together with the result of seeding it upon Wurtz litmus agar and upon lactose and glucose bouillon, all of which were maintained at incubator temperature of 4O°C. to 4i°C. The Wurtz agar plates gave evidence of the growth of organisms at this high temperature, with or without the formation of an acid. The sugar bouillon, in fermentation tubes, gave evidence of their power to disintegrate, or ferment sugars. The results of these tests are characteris- tic of those organisms usually found in waters, contaminated with human or animal excretions, and they are used to determine the fitness of waters for domestic use. The table also shows briefly the more marked *See Table on Page 330. BACTERIOLOGICAL INVESTIGATIONS. 329 cultural and physiological characteristics of the organisms which were selected from each fermentation tube. These special organisms, the study of which has only been sufficient to appropriately group them, were chosen as representing most clearly those, whose presence indicate faecal con- tamination. Most respectfully, Eugene Wasdin, M. D. June 12, 1897. 330 APPENDIX NO. 3. Number Source of Sample Calendar Date of Collection. 1897 Reactions with Reactions Produced by Bacteria, Isolated from Original Sample Remarks of VI Gas Pro- duction Ater Wurtz Litmus Agar No of Cultures Inc inTab'lat'n Nutrient Gelatine 1 Gas 1 Fermentation Tubes Litmus Milk Character of Growth on Potato Indol Glucose Bouillon Lactose Bouillon , Coagu- | lation Color [ Days iGrown Lac- tose Glu- cose Blue Red Gas Reaction Gas Reaction 1 Highland Reservoir March 19 + + + + 1 + 0 + 0 Alkaline 0 Alkaline + - 4 Dry-Brown- Wrinkled 0 Suspicious, Fer- menting Germ not Found Herron Hill Reservoir March 19 + + + + 1 + 0 + 0 Acid 0 Acid + Pink 4 Moist-Yellow- Expansion 0 Suspicious 3 4 Tap at Schenley Park March 19 + + + + 1 + 0 + 0 Acid 0 Acid Pink 4 Moist-Creamy- Expansion Moist-Creamy- Expansion 0 Suspicious Intestinal, Colon Group Highland Reservoir March 24 4" 4- + + + 2 0 +' + JI 1 co 2 ~ T Acid H T CO 2 2 Acid + - 4+14 0 1 + 0 + 0 Alkaline 0 Alkaline 0 - - Dry-Bro wn- Gi anular 0 - 5 6 Herron Hill Reservoir March 24 + + + 3 0 + + H o C02 - J Acid JL_ _ 2 CO 2 1 Acid • + Pink 14 Moist Glistcuiug- Furrowed-Granu'r 0 Suspicious 1 + 0 + o Alkaline 0 Alkaline 0 - - Opaque Center- Lighter Edges + Suspicious Tap at Schenley Park March 24 + + + + 1 0 + + 1 co2 Acid H 1 CO 2 - V Acid + - 4 - + Colon Group 1 0 + +. J? 1 CO 2 - 2 Acid Acid + Pink 14 - 0 Colon Group 1 + 0 0 0 Alkaline 0 Alkaline 0 Heliotrope - Moist-Creamy - Expansion 0 Proteus 7 Bedford Basin April 6 + + + + 1 1 0 + + J* 1 CO2 ~' 2 Acid H 1 CO2 - 1 Acid + Violet 5 Light Brown- Moist-Expan. + Colon Group 8 Garfield Tank April 6 + + + -1- 0 + + H_ = 1 CO2 T Acid = 1 co2 1 Acid 0 + Pink 14 Moist-Brown'h- Expansion 0 Colon Group 9 Tap at Colwell and Logan Sts. April 6 + + + 1 + 0 + - Acid H , 1 CO2 = J Acid Pink 5 Moist-Wrink'd- Expansion 0 Proteus 10 Highland Reservoir April 14 + + 0 + 1 0 0 H_ = 1 co2 Acid H 1 C03 - 2 Acid 4- 0 Pink 6 Moist-Brownish- Glistening-Expan. + Colon Group 11 Herron Hill Reservoir April 14 + + 0 + 1 0 0 + H = 1 CO2 1 Acid JL_ _ 1 C02 ~ T Acid Heliotrope 14 - + Colon Group 12 13 14 Tap at Point April 14 + + 0 + 1 0 ° + J* 1 CO2 ~ T Acid H 1 C02 - T Acid + Pink 14 - 0 Colon Group Tap on South Side April 22 + + 0 + 1 0 0 + JL_ = 1 C 0 0 1 Acid JL_ _ 1 C03 ~ T Acid 4- 0 Pink 5 Moist-Creamy-Exp Gas Bubbles 0 Bacillus lactis aero- genes. Colon Group Tap on South Side April 22 + + 0 + 1 1 o 0 + « 1 OO2 Acid _ 1 C02 " 2 Acid 0 Pink , 14 Creamy-Exp'n. Gas Bubbles + Bacillus lactis aero- genes. Colon Group 15 Tap on South Side April 22 + + 0 + 0 0 + H _ 1 CO2 Acid H = 1 GOo 2 Acid 0 Pink - Moist-Glist'ng- Expansion + Colon Group RESULTS OF BACTERIOLOGICAL EXAMINATION OF FIFTEEN DIFFERENT SAMPLES OF WATER, COLLECTED FROM THE PUBLIC WATER SUPPLY OF PITTSBURGH. Notes:-The plus sign (4-) means that the reaction is present. The zero sign (o) means that the reaction is not present. The dash sign (-) means that no determination was made, REPORT UPON Bacteriological and Microscopical Investigations, BY WM. R. COPELAND, BACTERIOLOGIST. APPENDIX No. 4- APPENDIX No. 4. Mr. Morris Knowles, Resident Engineer, Pittsburgh Filtration Commission. Sir :- I beg to submit the following report on the bacteriological and mi- croscopical investigations made in connection with the experiments con- ducted by the Filtration Commission. The numbers of bacteria, which were found in the effluents from the various filters and in samples from other sources, have been reported to you from time to time. The work consisted principally of the determination of the number of bacteria in samples of Allegheny River water, collected before and after filtration. During part of July and the month of August. 1897, samples were collected daily; and from September, 1897, to February, 1898, sam- ples were collected at least twice a day. After February, 1898, samples were collected several times each day. Samples were also collected sev- eral times each month from the watfr supplies of Pittsburgh and vicinity. Two other branches of work which were pursued as time allowed were devoted to the isolation of species of bacteria, and to the determination of the species and numbers of micro-organisms* in waters collected from the sources described in the preceding paragraph. The following report, therefore, has been divided into three parts. The first division describes the methods which were used to determine the numbers of bacteria in the waters examined; the second, methods used to isolate species of bacteria; the third, the method used in counting and enumerating the number of micro-organisms found. Table I. in Part II, contains a list of the species of bacteria found, and the tables appended to Part III contain lists of the micro-organisms. From July 1 to August 23, 1897, the bacteriological work was per- formed in the laboratory of the Bureau of Health. Department of Public Safety. After August 23, the work was done in a small laboratory near the filter plant at Brilliant. A portion of the time of the laboratory force was devoted to collecting samples from various points on the Allegheny River, to recording gage readings, to making out record sheets of the operations of filters, and to general supervision of the operations of the experimental filter plant. * The term micro-organisms, as used in this report, includes the minute forms of aqua- tic life, excepting bacteria, which must be studied by means of the microscope. 334 APPENDIX NO. 4, REPORT OF BACTERIOLOGIST. Methods Employed to Determine the Numbers of Bacteria in Water. PART I. The numbers of bacteria contained in waters were determined by ''Koch's Plate Culture" method. The glassware employed in these de- terminations was boiled in a strong solution of bichromate of potash and sulphuric acid. All traces of the latter Were removed, before the articles were used, by washing them in filtered water until the rinse water gave a neutral reaction with methyl orange. Glassware was sterilized by heat- ing it for two hours in a dry sterilizer at 2OO°C. The media used in making plate cultures were nutrient gelatine, nu- trient glycerine agar, and nutrient litmus lactose agar. The gelatine manufactured by Comte Fils of Magdebourg, and labeled premiere qualite, was employed because it had been adopted in other laboratories where special attention is given to the bacteriology of water. Thread agar, free from acid, and double distilled glycerine were used to make nutrient agar. Lactose agar was prepared by adding two per cent, of powdered crystalline lactose to nutrient glycerine agar neutral to phenol- phthalein; four drops of sterile aqueous solution of blue litmus were added to the lactose agar just before plating. The meat infusion used in media was prepared by soaking one part of finely chopped lean beef in two parts of distilled water for twenty hours at a temperature of io°C. Litmus has been employed extensively, in other laboratories, as an indicator in titrating nutrient gelatine. Mr. Geo. W. Fuller,1 however, has pointed out that phenolphthalein is more sensitive than litmus to weak organic acids. Phenolphthalein was used, therefore, in titrating nutrient media. Sodium hydrate was used to neutralize media. When hydrochloric acid is added to nutrient media containing an excess of sodium hydrate, salt is formed. It is pointed out in another article,2 in the Journal to which reference has just been made, that salt is unfavorable for the development of bacteria in media. In order to avoid the formation of salt, sulphuric acid was used instead of hydrochloric to acidify nutrient media. Twen- tieth normal solutions of sodium hydrate and sulphuric acid were used in making titrations. Five cubic centimeters of media, diluted with 50 cubic centimeters of distilled water, were boiled for two minutes in a white porcelain dish and the titrations made while the mixture was hot. The question of reaction of nutrient media is taken up more at length on page 339 of this report. Nutrient gelatine and agar were 1 "Proper Reaction of Nutrient Media for Bacterial Cultivation." Geo. W. Fuller, Journal of the American Public Health Association, Vol. XX, Oct., 1895, p. 565, et seq. 2 "The Influence of Variations in the Composition of Nutrient Gelatine upon the Devel- opment of Water Bacteria." Prof. Wm. T. Sedgwick and S. C. Prescott, Journal American Public Health Associa- tion, Vol. XX, 1895, p. 450 et seq. METHODS,-PLATING. 335 sterilized for five minutes in an autoclave at a pressure of 15 pounds. Lac- tose agar was sterilized for 25 to 30 minutes in an Arnold steam sterilizer on each of three consecutive days. All kinds of media were re-sterilized for ten minutes in boiling water, or in an autoclave for one minute at 15 pounds pressure before plating. For further particulars in regard to the method of preparing nutrient media, the reader is referred to the Twenty- .Seventh Annual Report of the Massachusetts State Board of Health. * plating. This process used in making cultures of samples of water in petri dishes is known as plating. The dishes used in plating varied somewhat in size. An average dish measured, inside, three and one-half inches in diameter and one-half an inch in depth. The numbers of bacteria in the waters analyzed ranged from many thousands in samples collected from the Allegheny River, to a few cells in the filtered water. Therefore, in order to give each colony ample food material for development, waters which contained more than three or four hundred bacteria per cubic centimeter were generally diluted with known volumes of sterile water before plating. This practice was followed in examining waters which contained large numbers of bacteria, except in a few cases when dealing with samples from new sources or collected for the purpose of illustrat- ing some special point. Waters which contained from 5,000 to 10,000 or more bacteria per cubic centimeter were diluted one part in fifty; samples, containing from 2,000 to 5,000 per cubic centimeter, were diluted one part in twenty-five of sterile water.* After plating the samples of water, the petri dishes were set in an ice chest, to allow the nutrient media to harden; and several hours later they were transferred to a thermostat. The plates were examined daily; and as soon as colonies had developed on a given plate to such a size that they threatened to destroy their neighbors, the number of colonies was counted, using a hand lens. Plates containing many liquefied colonies were placed in the ice chest after counting. The plates could generally be kept there for a day or two longer, because the low temperature checked the rapid development of liquefying forms. During these extra days, slow growing species had time to develop. The whole number of colonies finally counted contained, therefore, a greater proportion of the actual number of colonies on the plate than would have been obtained by keeping the plates at the warmer temperature of the thermostat, where the liquefying forms would have developed until they had turned the whole mass of nutrient media into water. *Twenty-Seventh Annual Report of the Massachusetts State Board of Health, 1895, p. 592, et seq. 336 APPENDIX NO. 4,-REPORT OF BACTERIOLOGIST. TEMPERATURE. One of the most perplexing problems encountered in the whole process of plate culture came from changes in temperature at different seasons of the year. The mercury often rose to 36°C. in the laboratory in summer and, in winter, it sometimes dropped to I5°C. on cold nights. The average daily temperatures in the thermostat, are given by months, in the following table:- Table A. Average Temperatures in Thermostat, by Months, in Degrees Centigrade A Average AVERAGE DAILY Difference Between EXTREMES DURING THE MONTH. Month. Year. Daily. Maximum. Minimum. Average Max imum and Minimum. Maxi- mum. Mini- mum. July 1897 CC 23-4 23-6 23-3 0-3 25-0 22.0 August . . 24-7 25-0 24-5 o-5 27.0 24.0 September 24-9 25-0 24-7 0-3 27.0 22.0 October . (( 21.5 21.6 21.3 o-3 24.0 20.0 November a 18.5 194 17.2 2.2 22.0 l6.O December cc 19.0 20.6 17-3 3-3 23-0 15-o January .. 1898 18.6 19-9 16.4 3-5 230 14.0 February . cc 19-5 21.0 16.9 4.1 22.0 9.0 March . . . cc 20.6 22.8 18.9 3-9 28.0 i5-o April .... CC 17-3 18.4 16.3 2.1 20.0 130 May (( 19.6 20.2 18.9 i-3 23-0 15.0 June .... cc 19.1 194 18.9 o-5 26.0 18.0 July cc 18.5 18.6 18.3 o-3 20.0 18.0 August . . (' 18.2 18.3 18.1 0.2 I9.O i7-5 September cc 17.7 l8.O 17-5 o-5 18.5 16.0 October . . (e 19-5 20.5 18.2 i-3 26.0 15.0 November cc 18.T 194 17-5 1.9 21.0 150 The figures given in the preceding table show that the average tem- perature varied considerably from day to day; the variations between the maximum and minimum often amounting to several degrees. The table also indicates that, in general, the temperatures were several degrees higher during the summer and autumn of 1897, than during the cor- responding months of 1898. These conditions were due to the following- causes:- The temperatures were high in the summer of 1897 because they were governed wholly by the temperature of the laboratory which was about the same as that of the outside air. After October a pipe leading from the water main was connected with the thermostat, for the purpose of keeping a constant current of cold water in circulation between the walls. Beside this device, a glass tube, holding a column of mercury, was hung in the water between the walls. *For a list of daily temperatures, see Table F at the end of Part i, Page 342. TEMPERATURE. 337 By expanding and contracting, the mercury decreased or increased the stream of gas which supplied a lighted Bunsen burner placed beneath the bottom. Theoretically, therefore, the temperature of the current of water circulating through the walls should have kept the column of mercury expanded to such a point that the flame of gas would supply just enough heat to maintain the temperature of the inner chamber of the thermostat at a given degree. Unfortunately, however, the river water often carried quantities of mud in suspension. This mud settled in the valves and stopped the current of water from circulating. Meantime, the gas flame beneath the thermostat continued to heat the water between the walls. This flame soon raised the temperature within the thermostat several degrees. Under such a condition the column of mercury expanded to a point where it cut off the supply of gas almost entirely. The flame then dropped to such a small jet that a slight current of air would blow it out. On the other hand, changes in the water pressure often increased the current of water in circulation. At such times a cold stream poured into the thermostat. If the gas flame had blown out and if no watchman was near to relight it, the temperature of the thermostat dropped several degrees. These conditions were modified in the spring of 1898, by having one of the assistant filter attendants read the temperatures frequently at night and adjust the flowing water. The preceding table shows the ad- vantage of this supervision, as the difference between the maximum and minimum temperatures decreased noticeably in April and in May. Dur- ing the summer weather the river water in the main became warm and the temperature often rose to 25°C. This was so high that the water could not be used to regulate the temperature of the thermostat. The effect of warm weather was lessened in the summer of 1898, by placing gelatine plates in a barrel sunk deep in a bank of earth and protected by doors from the heat of the sun. The preceding table shows that this simple device maintained a fairly uniform temperature during the summer of 1898. Nutrient gelatine melted during July and August, 1897, when allowed to stand for a few hours at the high temperature of the laboratory. Com- parisons made by plating duplicate samples of water on gelatine and agar, in warm weather, showed that when gelatine plates liquefied the numbers of colonies ran higher on nutrient glycerine agar than on gelatine. As these results corroborated the experience encountered at Lawrence and in other laboratories where glycerine agar has been used extensively, all samples were plated on glycerine agar during August and September, 1897. Nutrient gelatine, however, is used more extensively than agar in making examinations of water. As soon, therefore, as cooler weather returned in the fall, the samples were plated on gelatine instead of agar, and this practice was continued until the end of the work. 338 APPENDIX NO. 4,-REPORT OF BACTERIOLOGIST. Number of Days During Which Plates Were Allowed to Develop. Variations in temperature made it desirable to allow plates to develop for different periods at different seasons of the year. The high tempera- ture in the summer of 1897 was favorable for a rapid development of bacteria; during this period, the plates were kept from two to three days. When cooler weather began in the fall and the temperature of the thermostat dropped from 230 or 240 to 2i°C. the colonies of bacteria de- veloped more slowly. Under this condition, the plates were kept from three to four days. As a result of allowing plates to develop for one day longer the number of colonies increased as shown in the following table:-• Number of Colonies Which Developed on Gelatine Plates, Growing for Three and Fotir Days, at 21° Centigrade. Table B. Date, Growing for Three and Four Days, at 21° Centigrade. 24 Hours Ending Bacteria Per 9.00 A. M. Source of Sample. Cubic Centimeter. 1897. 3 Days. 4 Days. Sept. 29 29 Allegheny River at Millvale 3>925 4,325 Effluent from Crib at Millvale 2,850 3,125 Oct. 2&3 Gate Chamber, (Average of Two Days) 4,675 6,025 Ci Ci CC Effluent, Filter No. 1, (Average of Two Davs) 19 23 Ci CC iC Effluent, Filter No. 2, (Average of Two Days) 140 I48 5 Tap in Wilkinsburg 132 I48 6 Allegheny River at Hulton 11,750 12,250 " 6 Effluent from Crib at Hulton 4,960 6,336 " 8 Gate Chamber 18,200 18,900 " 8 Settled Water 4,025 6,100 " 8 Effluent, Filter No. 2 12 18 " 9 Effluent, Filter No. 1 19 23 This table shows that the number of colonies increased gradually from the third to the fourth day. After October 5, 1897, therefore, all plates were kept for four days, but when plates were kept for more than four days at this temperature, the bacteria liquefied the nutrient gelatine. On November 11, and December 18, 1897, the temperature of the thermostat rose to 25°C. for reasons described on page 337, and in con- sequence the nutrient gelatine in the plates melted. In order to prevent a recurrence of such a disastrous increase, the temperature of the ther- mostat was reduced to i8°C. on December 24, 1897. The reason for making the change was, that, even when the temperature rose three or four degrees, it only ran up to 22°C. instead of to 24°C.; nutrient gelatine, which melted at the latter temperature, remained solid at 22°C. When the plates were kept at i8°C. the colonies developed slowly. Under such conditions the number of colonies increased for five or six days. This point is illustrated in the following table, which gives, for each sample, the numbers of colonies counted upon the plates for suc- cessive davs:- TEMPERATURE-REACTION OF MEDIA. 339 Tabee C. Number of Colonies Which Developed on Gelatine Plates, Growing for Five and Six Days at 180 Centigrade. Date, 54 Hours Ending Bacteria Per 9.00 A. M. Source of Sample. Cubic Centimeter, 1897- 5 Days. 6 Days. Dec. 24 Ci Ci Settling Basin .... 81350 11,300 Tap at Herron Hill 7,000 7,150 cc a Effluent, Tile B. .. . 1,000 1,650 Ci a Effluent, Tile D. .. . 2,800 3,500 " 25 Gate Chamber 4,55o 5,250 Gate Chamber 4,200 4,800 Ci Settling Basin 7,450 8,600 CC Ci Effluent, Filter No. I 186 211 Ci Ci Effluent, Filter No. 2 i55 T57 " 27 Gate Chamber . . . . 2,800 3,250 Effluent, Filter No. I 59 94 cc cc Effluent, Filter No. I 48 57 41 28 Gate Chamber . . . . 2,350 2,800 cc Ci Settling Basin 4,95o 5,350 ci a Effluent, Filter No. I 69 75 a a Effluent, Filter No. 0 IQ7 222 XI (I Effluent, Tile C. .. . 675 1,075 Ci Ci Effluent, Tile F. .. . 650 850 " 2Q Gate Chamber . .. . 1,750 2,000 Ci i'i Settling Basin 5,000 5,4oo ci a Tap in Allegheny . . 7,350 8,050 a a Allegheny River at Etna 26,150 27,400 a a Tap at Millvale . .. . 2,500 3-125 The table shows, as a whole, that, after the plates had been kept for four days in the thermostat and then transferred to the ice chest, the num- ber of colonies counted increased from the fifth to the sixth day. A few plates were kept more than six days, but the liquefying colonies usually developed to such a degree that the number of colonies which could be counted decreased when the plates were kept for a longer period. REACTION OF MEDIA. The reaction of a nutrient medium exercises an important influence over the colonies which develop in the medium in which samples of water are plated. If the medium is either too acid or too alkaline, certain species of bacteria will not multiply rapidly, and the number of colonies which are found at the end of a few days will, therefore, be too low. For many years media which were neutral to litmus were used to determine the number of bacteria in water. The neutral point of litmus has a degree of reaction which is described by Mr. George W. Fuller* as about * 27th Annual Report, Massachusetts State Board of Health, 1895, P- 591 340 APPENDIX NO. 4,-REPORT OF BACTERIOLOGIST. 1.3 per cent, acid, on a scale established in titrating organic compounds with phenolphthalein as an indicator. This writer recommended that media should be made more acid than this, or about 1.5 per cent, acid to phenol. The article cited states, in another paragraph, ''The evidence at hand shows that the degree of reaction which is most favorable for bac- terial growth varies somewhat with different species of bacteria, and per- haps with seasons of the year." As suggested by this opinion, samples of water from different sources were plated from time to time in media having different degrees of reaction. The results obtained are given in the following table:- Table: D. Number of Colonics of Bacteria Which Developed in Nutrient Media Having Different Degrees of Reaction. Date, 24 Hours Ending 9.00 A. M. River Water. Neutral. Year. 2.0 Degrees of Reaction in Per Cent. i-5 1.0 o-5 July 28, 1897. 3,900 6,300 4,200 5,600 Oct. 7, U 18,550 8,250 . 7,550 7,400 Oct. 9, cc 22,200 18,550 19,250 18,500 Oct II, ii ' 32,730 22,000 17430 18,200 Nov. 22, CC 4,600 9,750 11,700 I4.6OO Dec. 4, 10,700 8.7OO 13,700 8,700 March 9, 1898. u 2,180 7,300 5,200 4,300 3,000 Alarch 17, 23,500 l6,OOO 13,450 8,000 10,300 Alarch 17, ic 16,100 15,400 13,200 14,100 16,700 March 25, ii 20,500 21,050 22,000 18,000 16,200 May 3, ii 3,000 3,400 3'300 2,900 Alay 22, ii 5,400 6,650 7,500 6,500 Al ay 26, 13,800 18,500 13,600 13,750 Effluents from Sand Filters. July 3b 1897- 37 61 34 69 Oct. ii 14 22 21 16 Oct. 9, ii 27 3i 23 23 Oct. 11, cc 186 219 in 70 Nov. 22, Ci 153 350 384 524 Nov. 22, (( 174 498 580 500 Dec 4. Ci 66 118 172 112 Alay 3, a 3i5 392 370 300 Alay 21, cc 68 80 82 73 60 Miscellaneous Samples. July 29, 1897- cc 33 72 59 48 Sept. 21, 30 47 160 79 Nov. 16, a 190 199 412 144 Alarch 9, 1898. • • • • 322 161 130 18 March 9, a 119 139 IIO 122 79 Alarch 17, a IIO 104 173 142 7i May 1, cc 60 42 28 15 May 4, a 7i5 810 790 710 Alav 26, (* 58 70 48 36 20 REACTION OF MEDIA. 341 This table shows that the most favorable degree of reaction varied somewhat at different seasons of the year. , Guided by the results obtained with the samples of filtered water the reaction of nutrient media was changed in October, 1897, from 1.5 to 1.0 per cent.; in November, 1897, from 1.0 to 0.7 per cent.; in December, 1897. from 0.7 to 1.0 per cent.; and in March, 1898, from 1.0 to 1.3 per cent. Table E. Averages of the Numbers of Bacteria Which Developed in Nutrient Media of Different Degrees of Reaction. Source of Sample. Degrees of Reaction in Per Cent. 2.0 i-5 1.0 o-5 Neutral. Raw Water . 10,568 14^48 12,050 10,644 12,900 Effluents from Filters. • 139 186 205 186 60 Other Effluents 182 183 212 I46 57 This table gives the averages of all the comparisons made during the year. It shows that the most favorable reaction lay between 1.5 and 1.0 per cent. The figures obtained up to March 1, 1898, seemed to point to this fact, and after March 1, 1898, all media used for the regular analyses were made with a reaction of 1.3 per cent. A further reason for selecting that special degree lay in the fact that, during the process of sterilizing, the acidity of the media often increased 0.1 or 0.2 per cent. Thus the, reaction of the media, at time of plating, approached, but did not exceed 1.5 per cent. 342 APPENDIX NO. 4,-REPORT OF BACTERIOLOGIST. • Date, 24 Hours Ending 9.00 A. M. July, 1897. August, 1897. September, 1897. October, 1897. November, 1897. December, 1897. January, 1898. February, 1898. March, 1898. Max. Min. Aver. Max. Min. Aver. Max. Min. Aver. Max. Min. Aver. Max. Min. Aver. Max. Min. Aver. Max Min. Aver. Max. Min. Aver. Max. Min. Aver. 1 3 4 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 23.0 23.0 25.0 24.0 22.0 24.0 24.0 24.0 23.0 23.0 23.0 24.0 22 0 24.0 24.0 23.0 23.0 23.0 24.0 24.0 22.0 '24.6 24.0 23.5 25.0 26.0 27.0 25.0 25.0 24.0 25.0 25.0 24.6 24.0 25.0 25.0 25.0 25.0 26.0 ::::: 25.0 24.0 24.0 24.0 25.0 24.0 24.0 24.0 24.0 25.0 25.5 26.5 25.0 24.5 24.0 24 5 25.0 24.0 24.0 24.5 24.5 25.0 25.0 24.0 25.0 26.0 27.0 27.0 27.0 27.0 24.0 23.0 23.0 23.0 25.0 24.0 24.0 25.0 25.0 26.0 27.0 27.0 27.0 24.0 23.0 23.0 22.0 25.0 24.5 24.0 :::::: '25.6 25.5 26.5 27.0 27.0 27.0 24.0 23.6 23.0 22.5 21.0 21.0 21.0 21.0 21.0 20.6 20.0 22.0 22.0 '24.6 24.0 22.6 22.0 22.0 21.0 21.0 21.0 21.0 21.0 20.0 20.0 20.0 20.0 22.0 24.6 24.0 22.0 22.0 21.0 21.0 21.0 21.0 21.0 21.0 20.5 20.0 20.0 21.0 22.0 '24.6 24.0 22.0 22.0 21.5 21.0 22.6 19.0 19.0 20.0 20.0 17.0 16.0 17.0 19.0 22.0 21.0 21.0 19.0 16.0 16.0 16.0 19.0 17.0 16.0 16.0 16.0 17.0 18.0 19.0 21.0 16.0 19.6 17.5 18.2 19.7 18.5 16.5 16.0 16.5 18.2 20.2 20.5 21.0 18.7 22.0 22.0 20.0 21.0 21.0 21.0 22.0 19.0 20.0 21.0 22.0 22.0 18.0 19.0 21.0 23.0 23.0 20.0 22.0 22.0 21.0 21.0 21.0 18.0 19.0 19.0 19.0 16.0 22.0 22.0 20.0 16.0 19.0 19.0 20.0 18.0 18.0 17.0 16.0 16.0 20.0 21.0 16.0 18.0 18.0 18.0 18.0 16.0 16.0 16.0 21.0 18.0 18.0 16.0 16.0 15.0 15.0 16.0 16.0 16.0 16.0 16.0 19.5 20.2 19.7 20.2 20.2 18.7 20.5 17.7 18.7 20.2 21.7 18.0 18.0 18.5 19.5 20.0 20.7 18.0 20.0 21.2 20.2 19.2 18.2 17.0 17.8 17.5 17.5 16.0 19.0 19.0 18.3 21.0 21.0 20.0 21.0 22.0 19.0 18.0 23.0 18.0 19.0 19.0 19.0 21.0 21.0 19.0 19.0 20.0 20.0 20.0 21.0 17.0 20.0 22.0 21.0 21.0 20.0 18.0 21.0 18.0 18.0 16.0 16.0 15.0 15.0 18.0 16.0 16.0 14.0 15.0 15.0 19.0 19.0 19.0 19.0 19.0 15.0 15.0 15.0 16.0 17.0 17.0 17.0 16.0 16.0 18.0 16.0 16.0 16.0 16.0 16.0 18.3 20.0 17.7 19.9 20.6 18.0 17.3 17.7 16.7 18.0 19.0 19.0 20.0 20.0 19.0 18.0 17.5 18.5 19.2 19.5 17.0 20.0 20.2 18.8 20.5 18.5 17.6 18.7 17.0 17.0 21.0 21.0 22.0 22.6 22.0 20.0 19.0 20.0 21.0 21.0 21.0 21.0 22.0 22.0 21.0 20.0 16.0 9.0 9.0 16.0 16.0 19.0 19.0 19.0 19.0 20.0 18.0 18.0 20.0 20.0 15.0 18.0 19.5 17.0 20.5 19.5 20.0 19.7 19.0 19.5 20.0 20.2 19.2 19.5 21.2 21.2 17.7 18.5 20.0 20.0 22.0 22.0 23.0 23.0 23.0 24.0 24.0 23.0 23.0 23.0 23.0 23.0 23.0 24.0 24.0 22.0 22.0 20.0 22.0 28.0 18.0 19.0 16.0 18.0 20.0 21.0 16.0 16.0 20.0 19.0 19.0 15.0 20.0 22.0 18.0 22.0 19.0 19.0 19.0 19.0 20.0 22.0 19.0 19.7 18.7 19.8 21.3 22.0 19.5 20.5 21.8 20.5 20.2 18.7 21.5 22.5 20.8 22.7 21.2 20.2 19.7 19.5 20.3 23.5 Av'gs, 23.6 23.2 23.4 25.0 24.5 24.7 25.1 24.8 24.9 21.6 21.3 21.5 19.4 17.2 18.5 20.6 17.3 19.1 19.9 16.4 18.6 21.0 16.9 19.5 22.8 18.9 20.6 TABLE F. RECORD OF DAILY TEMPERATURES IN THERMOSTAT, IN DEGREES, CENTIGRADE. TEEPERATURES IN THERMOSTAT. 343 Date. 24 Hours April, 1898. May, 1898. June, 1898. July, 1898. August, 1898. September, 1898. October, 1898. November, 1898. December, 1898. Aver. 9.00 A. M. Max Min. Aver. Max. Min. Aver Max. Min. Aver. Max. Min. Max. Min. Aver. Max. Min. Aver. Max. Min. Aver. Max. Min. Aver. Max. Min. Aver 1 18.0 17.0 17.2 22.5 21.5 22.0 19.5 19.0 19.2 18.0 18.0 18.0 20.0 18.0 18.5 19.0 17.0 18.0 2 19.0 18.0 18.2 I 25.0 22.0 24.2 19.5 19.0 19.2 ..... . 18.5 18.0 18.2 22.0 22.6 22.0 20.0 17.0 18.7 19.0 18.0 18.3 3 20.0 18.5 18.8 25.7 24.0 25.1 20.0 19.0 19.5 18.5 18.5 18.5 24.0 22.0 23.0 18.0 17.0 17.8 19.0 17.0 17.8 4 18.0 13.0 15.7 20.0 18.5 19.2 26.0 25.0 25.9 21.0 20.0 20.5 19.0 18.5 18.7 26.0 24.0 25.3 18.0 18.0 18.0 20.0 18.5 19.1 5 18.0 14.0 16.5 20.0 18.0 18.9 26.0 22.0 22.9 21.0 20.0 20.5 19.0 18.0 18.5 18.0 18.0 18.0 25.0 24.0 24.5 18.0 18.0 18.0 20.0 17.5 18.5 6 22.0 18.0 17.0 19.0 16.0 18.1 18.0 18.0 18.0 20.0 19.0 19.5 18.5 18.0 18.2 18.0 18.0 18.0 26.0 20.0 24.3 19.0 18.0 18.5 20.0 18.0 18.6 7 19.0 18.0 18.2 18.0 16.0 17.7 18.0 18.0 18.0 19.0 19.0 19.0 18.5 18.0 18.2 18.0 18.0 18.0 22.0 19.0 21.2 18.0 18.0 18.0 20.5 18.5 19.7 8 19.0 16.0 17.2 18.0 15.0 15.7 18.5 18.5 18.5 19.0 18.5 18.7 18.0 18.0 18.0 18.0 18.0 18.0 21.0 19.0 20.0 18.0 17.5 17.8 19.5 18.0 18.2 9 20.0 17.0 18.0 16.5 16.0 16.4 18.0 18.0 18.0 18.5 18.0 18.2 18.0 18.0 18.0 18.0 18.0 18.0 21.0 19.0 20.5 19.5 17.5 19.0 19.0 18.0 18.7 10 20.0 13.0 16.0 16.5 16.0 16.2 18.0 18.0 18.0 18.0 18.0 18.0 18.0 17.5 17.7 18.0 18.0 18.0 19.0 19.0 19 0 21.0 18.0 19.1 18.0 18.0 18.0 11 19.0 18.0 18.5 18.0 16.0 17.7 18.0 18.0 18.0 18.0 18.0 18.0 17.5 17.5 17.5 20.0 19.0 19.5 21.0 17.5 18.8 18.0 18.0 18.0 12 19.0 17.0 18.0 19.0 18.0 18.9 18.0 18.0 18 0 18.0 18.0 18.0 17.5 17.5 17.5 19.0 19.0 19.0 20.0 17.5 18.6 18.0 18.0 18.0 13 19.0 17.0 17.7 19.0 18.0 18.9 18.0 18.0 18.0 18.0 18.0 18.0 18.0 17.5 17.7 20.0 18.5 19.3 19.0 18.0 18.7 19.0 17.0 18.2 14 18.0 17.0 17.2 19.0 18.0 18.6 19.5 18.0 18.0 18.0 18.0 18.0 18.0 18.0 18.0 18.5 18.5 18.5 19.5 19.0 19.1 20.0 19.0 19.5 15 18.0 17.0 17.2 20.0 19.0 19.1 19.0 18.0 18.3 18.0 18.0 18.0 18.0 18.0 18.0 18.5 18.5 18.5 19.0 17.0 18.3 19.5 18.5 18.8 19.0 17.0 18.5 16 19.0 17.0 17.5 20.5 20.0 20.1 18.0 18.0 18.0 18.0 18.0 18.0 18.0 18.0 18.0 18.5 17.0 17.7 18.0 16.0 17.2 19.0 18.0 18.5 19 0 17.0 18.0 17 17.0 16.0 16.5 20.0 18.5 19.5 18.0 18.0 18.0 18.0 18.0 18.0 18.0 18.0 18.0 18.0 17.0 17.5 16.0 15.0 15.2 19.5 18.0 19.0 19.0 18.0 18.5 18 20.0 17.0 18.1 20 0 18.5 19.5 18.0 18.0 18.0 18.5 18.0 18.2 18.5 18.0 18.2 18 0 18.0 18.0 18.0 15.0 16.8 21.0 16.5 18.7 19.0 19.0 19.0 19 19.0 18.0 18.2 20.0 19.0 19.6 18.0 18.0 18.0 18.5 18.0 18.2 19.0 18.5 18.7 18.0 17.5 17.7 18.5 17.0 17.9 19.0 16.5 18.0 19.0 17.0 18.7 20 19.0 17.0 18.0 22.0 20.0 20.2 18.0 18.0 18.0 18.5 18.0 18.2 19.0 19.0 19.0 17.5 16.0 16.7 17.5 16.0 16.8 20.0 15.0 17.4 19.0 17.0 18.0 21 17.0 16.0 16.0 22.0 21.5 21.7 18.0 18.0 18.0 19.0 18.5 18.7 19.0 19.0 19.0 17.0 16.0 16.5 18.0 16.0 17.2 20.0 18.0 18.6 18.0 17.0 17.5 22 17.5 16.0 17.0 22.5 21.5 21.9 18.0 18.0 18.0 19.0 18.0 18.5 19.0 19.0 19.0 17.5 17.0 17.2 17.0 17.0 17.0 19.0 18.0 18.6 19.0 17.0 18.2 23 17.0 16.0 16.5 22.5 21.2 21.5 18.0 18.0 18.0 18.0 18.0 18.0 18,0 17.5 17.7 17.0 16.0 16.5 19.0 17.0 18.0 24 : 18.0 16.0 17.0 22.0 21.0 21.7 18.0 18.0 18.0 18.0 18.0 18.0 18.0 17.5 17.7 21.0 16.0 18.5 19.0 18.0 18.3 18.0 15.6 16.5 25 18.0 16.0 17.0 22.5 21.0 21.9 18.5 18.0 18.2 18.0 18.0 18.0 18.5 17.5 18.0 21.0 17.0 19.0 21.0 18.5 19.5 19.0 15.0 17.7 26 18.0 17.0 17.7 22.5 21.0 21.6 18.5 18.5 18.5 18.0 18.0 18.0 18.5 18.0 18.2 22.0 17.0 19.5 21.0 17.0 18.5 19.0 19.0 19.0 27 18.0 16.0 17.2 21.5 21.0 21.6 18.5 18.5 18.5 18.0 18.0 18.0 18.5 18.0 18.2 23.0 22.0 22.5 19.0 17.0 18.0 19.0 11.0 17.0 28 17.0 16.0 16.7 21.5 21.5 21.5 18.5 18.5 18.5 18.0 18.0 18.0 18.5 17.0 17.7 23.0 15.0 19.0 19.0 17.0 18.0 18.0 11.0 15.7 29 18.0 17.0 17.8 22.0 21.5 21.8 18.5 18.5 18.5 18.0 18.0 18.0 17.0 16.5 16.7 19.0 15.0 17.5 19*0 18.0 18.5 19.0 18.0 18.3 30 18.0 17.0 17.2 22.5 21.0 22.0 19.0 18.5 18.7 18.0 18.0 18.0 22.0 19.0 20.7 19.0 16.0 17.3 19.0 18.0 18.2 31 23.0 21.0 22.0 18.0 18.0 18.0 22.0 18.0 20.0 f 19.0 18.0 18.7 Av'gs. 18.5 16.4 17.2 20.2 18.9 19.6 19.4 18.9 19.1 18.6 18.3 18.5 18.3 18.1 18.2 18.0 17.5 17.7 20.5 18.2 19.5 19.4 17.5 18.4 19.0 17.1 18.2 TABLE F,-(Continued.) RECORD OF DAILY TEMPERATURES IN THERMOSTAT, IN DEGREES, CENTIGRADE. 344 APPENDIX NO. 4,-REPORT OF BACTERIOLOGIST. PART II. Species of Bacteria. The second part of this Report contains a brief account of the "Spe- cies of Bacteria" which were found during October and November, 1897, in the Allegheny River water, before and after filtration; and of those species which were found in greatest numbers in the water supply of Pitts- burgh during August and September, 1898. In addition to these studies, a short description is given of tests made for the Bacillus coli communis' There are several facts which must be borne in mind in connection with the study of bacteria. In the first place, these small organisms are living plants; they are so minute that they cannot be identified by their form alone; and, therefore, must be studied under artificial cultivation. The characteristics of species may be made stronger, or they may be modified, by changes in the conditions which surround them. And, fin- ally, bacteriologists have not yet united upon a series of tests which they consider to be sufficiently complete to form a standard method for identi- fying species of bacteria. In carrying out the work described in the following pages, the meth- ods were selected from the list described as "Necessary Information Tests" in the "Report of American Bacteriologists" to the "Committee on the Pollution of Water Supplies" of the "American Public Health Association.* In order to secure suitable material for a study of species of bacteria, pure cultures were made from the clearly defined colonies which de- veloped in nutrient gelatine, seeded with samples of water collected from the sources described on page 346. These cultures were transferred afterward to various media and the reactions which they produced were used to identify the forms. SPECIES OF BACTERIA FOUND IN THE ALLEGHENY RIVER WATER. BEFORE AND AFTER FILTRATION. The bacterial efficiency of Filters Nos. 1 and 2 was high during October, 1897. The reason for this was that the number of bacteria was large in the river, and was small in the effluent. During the latter part of November, 1897, ^ie bacterial efficiency decreased. Three or four species of bacteria were often found during these two periods. The names of the species and the number of colonies belonging to each, which were found in a cubic centimeter of the raw and filtered water at the time, are given in the following table:- * This Report was submitted at the meeting of the Association in Philadelphia, Pa., September, 1897. SPECIES OF BACTERIA. 345 Table G. Species of -Bacteria Found in the Allegheny River Water, before and after Filtration; During October and November, i8gp. Date, 24 Hours Binding 9.00 A. M. Source of Sample. NUMBER OF BACTERIA PER CUBIC CENTIMETER, BELONGING TO THE SPECIES. Including All Kinds of Bacteria. Bacillus Albus. Bacillus Ochraceozis. Bacillus Fluorescens Liquefaciens. Bacillus Punctatus. Oct. 23, 1897. River Water, I57,5°° 147,400 22,000 75 50 " 23, Effluent, Filter No. 1. 18 8 I 3 " 23, Effluent, Filter No. 2. 26 13 2 10 Nov. 18, River Water, 19,000 18,200 35° H5 125 " 17, * Effluent, Filter No. 1. 1,230 1,120 7 84 21 " 18, * Effluent, Filter No. 2. 5,56° 5,530 i5 280 35 This table shows that the species which were most common in the river were found in the effluent, both in October and in November. The point of special interest, however, is that the species occurred in very much greater numbers in the effluent in November than in October. APPLICATION OF BACILLUS PRODIGIOSUS. The number of bacteria continued to be high during December and January following. In order to determine whether these high numbers were due to the presence of bacteria which found their way to the under- drains between the sand and the concrete walls of the filter, pure cultures of the Bacillus prodigiosus were mixed with the raw water and applied to the surface of Filter No. 2. The method used in applying these bacteria was as follows. Gallon bottles, containing a sterile solution of one-tenth of a per cent, of peptone and two-tenths of a per cent, of glucose in dis- tilled water, were inoculated with a pure culture of the B. prodigiosus. The bottles were place in & thermostat at a temperature of about i8°C., and allowed to incubate for four days. Portions of this mixture were scattered over the surface of the water on the filter every half hour for ten hours, beginning at 9.00 A. M., January 28, and again at 9.00 A. M., Jan- uary 29, 1898. The number of cells of B. prodigiosus was determined in each cubic centimeter of the mixture, and the number of cells of B. prodigiosus applied was estimated to be about 3,600 per cubic centimeter of water filtered on January 28, and 9,000 per cubic centimeter on Jan- uary 29. * A detailed description of the causes of the high numbers in the effluent, at this time,, will be found on Page 120 of the Resident Engineer's Report. 346 APPENDIX NO. 4,-REPORT OF BACTERIOLOGIST. Table H. Number of Water Bacteria and of Bacillus Prodigiosus, Found in the Effluent from Filter No. 2, on January 28 and 29, 1898. Number per Cubic Centimeter. Calendar Water Bacteria. Bacillus Remarks. Date, 1898. Hour. Prodigiosus. Jan. 28. 8.20 A. M. 218 O Before Application. Ci 12.00 M. 260 O 4 4 2.00 P. M. 294 O Average Number of 44 3.00 " 230 O Bacillus prodigiosus 4 c 4.00 " 238 O Applied, 3,600 Per I I 5.00 " 278 O Cubic Centimeter. I 4 6.00 " 230 O iC 8.20 " 172 2 C 4 10.00 " 166 O 4 4 12.00 Mid't. 352 O Jan. 29. 2.00 A. M. 328 O 44 4.00 " 332 O Average Number of 44 6.00 " 338 O Bacillus prodigiosus 4 4 8.00 " 313 O Applied, 9,000 Per 4 4 8.50 " 176 O Cubic Centimeter. 4 4 10.05 " 114 6 4 4 12.00 M. 144 I 4 4 2.00 P. M. 308 0 4 4 3.06 " 167 I 4 4 4-04 " 145 5 4 4 5-°o " 176 4 4 4 6.00 " 140 4 44 8.50 " 131 5 4 4 12.00 Mid't. tor 8 Jan. 30. 2.00 A. M. in 16 4 4 4.00 " 93 16 44 6.00 " 102 12 Seven samples of effluent were collected during each period of ten hours; and the records in the preceding table show that very few cells of B. prodigiosus were found in these samples. They occurred more frequently in samples collected after the ten hours had passed than during the period of application. This fact goes to prove that the cells of B. prodigiosus did not pass readily from the surface to the underdrains. Data, obtained from experiments made at Lawrence, Mass., indicate that cells of B. prodigiosus may pass through a sand filter in small num- bers. The presence, therefore, of the few cells which appeared in the effluent from Filter No. 2, after the application was concluded, did not prove that channels had been formed between the bed of sand and concrete walls of the filter. SPECIES OF BACTERIA FOUND IN SAMPLES OF ALLEGHENY RIVER WATER, COLLECTED FROM THE GATE CHAMBER AND FROM RESERVOIRS AND TAPS IN PITTSBURGH. Eight sets of samples were collected from the gate chamber, from each of three reservoirs, and from taps in residences near the reservoirs. One set of samples was also collected from a tap in the heart of the SPECIES OF BACTERIA. 347 city. When these waters were plated in nutrient gelatine many colonies of bacteria developed which had characteristic forms. Other colonies could not be distinguished so easily. In selecting material from which to take cultures for special study, colonies were chosen which represented the different kinds on each plate. As soon as pure cultures had been obtained of these forms, they were compared, one with another, by making cultures in nutrient gelatine contained in plates and test tubes. By this method many duplicates were detected. For the purpose of final study, cultures were selected, some of which were representative of the duplicate forms, and others of forms having special characteristics. The organisms used in making the tests were taken from cultures which had been grown for 48 hours on nutrient glycerine agar (reaction 1.5 per cent.). In order to prepare these stock cultures, the organisms in the original samples were transferred to gelatine plates; and from the plates pure cultures were transferred to tubes of gelatine. From these tubes they were transferred to bouillon (reaction 1.5 per cent.), then from the first tube of bouillon to a second, and, finally, from the second to the surface of nutrient glycerine agar. During each of these stages the organisms were allowed to develop for 48 hours at i8°C., before they were transferred to a new medium. A list of the species which were found in water taken from taps in Pittsburgh, and which gave the most characteristic reactions, are pre- sented, together with the results of the tests, in Table I.* The reactions which are recorded in this table were obtained by allowing the cultures to develop for ten days at from 170 to I9°C. The thermal death point was found by inoculating each of five tubes, containing 10 c. c. nutrient broth (reaction 1.5 per cent, acid), three times with a platinum wire loop filled with a drop of bouillon con- taining a pure culture of a given species. One of these tubes was placed in a water bath (depth of water about three inches), having a temperature of 5o°C.; other tubes were placed in baths at temperatures of 53°, 56°, and 59°C. The tubes were kept in the baths for ten minutes. They were watched carefully and the temperatures maintained exactly at the specified point. After they had been taken out from the bath, they were placed in ice water until cold, and then set in an incubator at about i8°C. The thermal death point is given, as lying between the point where a growth was found and the point where the tubes were sterile. All cul- tures were examined at the end of ten days. The results obtained in the tests are recorded either as positive or negative. Reactions which were well defined are recorded by a plus sign, ( +). In cases where no reaction was found or where they were ill defined at the end of ten days they are recorded by a zero, (o). *Opposite Page 348. 348 APPENDIX NO. 4,-REPORT OF BACTERIOLOGIST. In making the diagnoses of the various organisms, they were not tested for pathogenic properties. The time at the disposal of the Com- mission was too limited to make such tests complete. Tests for the Bacillus Coli Communis. During the months of July and August, 1897, several cases of typhoid fever developed in the 21st Ward of Pittsburgh, and in one of the neigbor- ing towns. Samples were collected from certain taps, springs or wells, and milk used by the families where the fever prevailed. The number of bacteria in the samples was determined; and further tests of the water and milk were made by plating them on Wurtz litmus lactose agar. These agar plates were allowed to develop for 14 hours in a thermostat, at a temperature of 38°C. or 39°C. Under such conditions the Bacillus coli communis should pro- duce bright red colonies. Cultures were taken, therefore, from the colonies on these plates which possessed the characteristic form of colonies of the B. coli communis and were transplanted into tubes of milk, nitrate, indol, and fermentation solution, also as stab cultures in tubes of nutrient gelatine. Cultures which gave reactions in these media characteristic of coli were considered to belong to the colon group and to be indicative of faecal contamination. Similar tests were made upon samples of water collected from the Allegheny and Monongahela Rivers and from reser- voirs and taps in different parts of the city. The results of these tests showed that bacteria which belonged to the colon group were present in samples collected from all of these localities, in numbers ranging from one to six per cubic centimeter at different seasons of the year. Before closing this part of the report attention should be called to the difficulties encountered in carrying out the work of isolating species of bacteria. As bacteria are living organisms, they have periods of growth and decay. In order to secure the reactions which are characteris- tic of a given species, cultures must be obtained from a single cell. Other- wise the cultures may contain more than a single species. The vitality of the original cell may be effected very decidedly by the composition of the media in which the organism is growing, and by the length of time during which the Organism has been under cultivation. By slight differences in composition of the food material, cultures may be made to produce reactions which differ in degree of intensity. It is also true that the different varieties of a given species produce reactions which differ in their degree of intensity. When the cultures produce such varia- tions, the student's only resource is to make tests of duplicate cultures, taking care to keep all conditions parallel. These tests must proceed slowly and be repeated several times. Such comparisons have been carried out in the work described above as far as time would allow. TABLE I. REACTIONS PRODUCED BY SEVENTEEN SPECIES OF BACTERIA FOUND IN TAP WATERS OF THE PUBLIC AV ATER SUPPLY OF PITTSBURGH. Number. Calen- dar Date of Collec- tion, 1898. Name. Mor- phology. Motile. Pig- ment Form- ed. Tempera- ture. Degrees C. Gelatine. Agar Tube. Meat In- fusion. Indol. Ni- trate. Fermentation OF SUGAli. Blood Serum. Milk. Reac- tion. Litmus Milk. Potato. Form. Spores. Diameter in M. M. Growth at 18°. Growth at 37°. Thermal Death Point. Liquefaction. Stab Growth. Color. Plate Colonies. Extent of Growth. Character of Growth. Turbidity. Pellicle. Reduced. Nitrous Acid. Gas Formed in Turbidity in Closed Arm. Visible Growth. Color. Liquefaction. Coagulation. Casein Red. Blue. Visible Growth. Color. Growth. Pellicle. Glucose. Lactose. Saccha- rose. | Glucose, j Lactose. ! 2 o p Formed. 6 : gj 5 1 Aug. 24 Bacillus albus B. o 0.50 + 0 + 0 54-55 0 Pellicle: thick, white. Line: white, small balls. Pearl gray Deep: colonies, round, white, granular. [raised, glist. Surface : colonies, small, Luxuriant Thick, white, like wax. + 0 0 o 0 0 0 0 0 0 0 + Flesh 0 0 0 0 * Neu- tral 0 0 + Dirty white Dirty, white, lux- uriant along line. 2 Aug. 24 B. radiatus aquatilis B. o 0 50 + Orange + 0 50 - + Pellicle: slight, wrinkled. Surface-growth, orange. Line: slight, and orange. Orange Deep: round, light bluish. Surface : rais ed, wrinkled, hairy. Slight Thin, moist, orange. + 0 0 0 0 0 0 0 0 0 0 + Orange 0 0 0 0 * Neu- tral < + 0 + Orange Slight orange along line. 3 Aug. 25 B. brunneus B. 0 0.50 0 Brown + + + Pellicle: sunken, flesh color. Line: consists of small balls. Gelatine, deep brown. Brown Deep: brownish. Surface: flesh. Slight Very thin, glistening, spreading. 0 0 0 0 0 0 0 0 0 0 0 0 0 0 + + Brown whey + * Neu- tral 0 0 + Red Resembles thread of raw beef. 4 Aug. 24 B. circulans B. + 1.25 + 0 + + 50 - + Air space at top, white flocks in stab. Gray Deep: brownish, 1 airy. Surface: gray, hairy mass in bottom of liquified zone. Slight Thin, moist, translucent, spreading. + 0 0 + 0 0 0 0 + + 0 + Gray 0 + + 0 Acid + 0 + White Thin and frosted. 5 Aug. 24 B. cloacae B. + 0.75 + 0 + + 59 + + Gelatine wholly liquified, liquor turbid, collection of white flocks at bottom. Gray Deep: gray, threads, floating in clear liquor. Luxuriant Moist, white, glistening, spreading. + + + + + + + + + + + + Gray + 4- + Whey liquified + Acid + 0 + Yellow- ish white Moist, spreading. 6 Sept. 29 B. coll com- munis B. 0 0.75 + 0 + + 59 + 0 Pellicle: thin, spreading,pearl gray. Line: thick, ending in balls. White Deep: round, granular, brownish. [glistening. Surface: spreading, wrinkled, Luxuriant White, thin, waxy, spreading. + + + 0 0 + + + + + + + Gray 0 + + Curds 0 Acid + 0 + Dirty white Thick, cream white. 7 Sept. 1 B. fulvus B. 0 0.50 0 Orange + 0 50- + Pellicle: orange, floating in clear liquor. Line: filled with orange flocks. Orange Deep: orange, irregular, gran- ular. Surface: raised, granular. Luxuriant Orange, thin, glistening, spreading. + 0 + 0 0 0 0 0 0 0 0 + Orange + + + Casein whey + Acid + 0 + Orange Spreading. 8 Sept. 1 B. hyalinus B. + 1.00 -4- 0 + + 59 + + Pellicle: thick, waxy, floating on turbid liquor. Line: liquified, flocks on bot- tom. White Deep: hairy, pellicle at bottom of pear-shaped cavity. Luxuriant Thin, warty, spreading. + + + + + 0 0 0 + 0 0 + Gray + + + Brown whey + Acid + 0 + White Thin, dry, wrin- kled. 9 July 16 B. janthinus B. + 0.75 + Purple to violet + 0 57-58 + Pellicle: purple. Line: filled with purple and gray flocks. Purple Deep: round, slight hairy, purple pellicle, small cup- shaped cavity. Luxuriant Purple, glistening, spreading. + + 0 + 0 0 0 0 + + + + Purple 0 + + + Acid + 0 + Purple Dark purple, spreading. 10 June 25 B. fluorescens liquefaciens B. 0 0.75 + Fluor- escent. + 0 54-55 + Pellicle: thick, white. Line: liquified, thick gray flocks. White Deep: round, hairy, brownish. Surface: granular, spreading. Luxuriant Fluorescent, white, thick spreading. + + 0 0 0 0 0 0 0 0 0 + Gray 0 + + Curds 0 Acid + 0 + Choco- late. Vitreous, spread- ing. 11 Sept. 1 B. ochraceus B. 0 0.50 + Orange + + 57-58 + Pellicle: orange. Line: heavy, ending in balls. Orange Deep : orange, glistening, oval, granular. Surface: round, granular, ragged edge. Luxuriant Canary yellow, dry, spreading. + + 0 0 0 + + + + + -1- + Light yellow 0 + + 0 Acid 0 0 + Orange Luxuriant. 12 July 16 B. plicatus B. 0 0.25 + Orange + + 57-58 + Pellicle: orange. Line: medium, ending in balls. Orange Deep: small, round, granular. Surface: yellow, lobbed like a berry. Slight Confined to line, orange. + 0 0 0 0 0 0 0 0 0 0 + Light brown 0 + 4- Casein partly decomp. + acid i + 0 + Deep orange Along line. 13 Aug. 25 B. punctatus B. + 0.50 + Gray + + 51-52 + Gelatine wholly liquified, liquor turbid. Pellicle: slight gray. Line: gray flocks. Gray Deep: gray, pellicle with white points connected by threads floating in saucer-shaped cavity. Luxuriant Pink, spreading. + + + + + + + + + -1- + + Dark brown + + + Whey + Acid + 0 + Choco- late. Waxy, spreading, dark brown. 14 Sept. 1 B. ramosus B. + 0.75 + Gray + 0 50 - + Pellicle: white, hairy, in clear liquor. [fuzzy threads. Line: distinct, projecting Gray Deep: gray, hairy, pellicle floating in clear liquor. Luxuriant White, thick, hairs rad at - ing from edge, spreading. + + 0 0 0 0 0 0 + + + + Gray + + + Faecal odor + Add j + • 1 + Gray Dirty white, moist, raised. 15 Aug. 25 B. rubescens B. + 0.50 + Pink + + 51-52 0 Pellicle: slight, raised, pink. Line: indistinct. Light brown D ep : round or oval, granu- lar, brownish. Surface: raised, white, glist. Slight Thin, translucent, wrinkled, spreading. + + 0 0 0 0 0 0 0 0 + Flesh 0 0 0 0 Alk- aline. 0 + ■ 1 + Pink Luxuriant, slight pink. « Sept. 1 B. tremelloides B. 0 0.25 + Yellow + + 51-52 + Pellicle: deep orange, floating in clear liquor. Line: filled, feathery flocks. Yellow Deep ; yellow, irregular pel- licle floating in clear liquor. Slight Slight, orange, thin, moist, spreading. + + 0 0 0 0 0 0 0 0 0 I + Orange + + Whey + Acid + 0 Yellow Very slight. 17 Sept. 1 B. ubiquitus B. 0 0.50 0 0 + + 57-58 0 Pellicle: raised white. Line: distinct. White Deep: round, white, srranular. Surface: raised and glistening. Slight Moist, confined to line. + + 0 + 0 0 0 0 + + + + Cream white 0 + + Whey 0 Acid j + 0 r White Thin, moist, [ spreading. * Note:-The term " Neutral when applied to the reaction produced by a culture, signifies that the organism did not change the reaction of the media. SPECIES OF BACTERIA,-MICRO-ORGANISMS. 349 PART III. Micro-Organisms. The following portion of the report contains the records of the work performed in identifying the species and in counting the numbers of micro-organisms found in samples of water collected from the Alle- gheny River, from the gate chamber, from the effluents of the filters, and from the reservoirs in Pittsburgh and in Wilkinsburg. The samples were collected in clean glass bottles having a capacity of one liter. The bottles were plunged a few inches below the surface, filled with water, corked, and carried to the laboratory at once. The samples were examined by the Sedgwick-Rafter method. Filter funnels used in filtering the waters were of the improved type recommended by D. D. Jackson.* When microscopical examinations are being made of surface waters, 250 c. c. are usually taken from each sample for analysis. As this quantity seemed to be small, 500 c. c. were generally filtered instead. Occasionally, however, some of the waters were very muddy. At such times the material gathered by filtering 500 c. c. would have contained a largq amount of clay. This sediment would have interfered with the process of counting the micro-organisms. In order to avoid this complication 250 c. c. of muddy water were taken for analysis. The micro-organisms, found in the waters examined, varied in species and in numbers at different seasons. Filamentous Algae were never found in any considerable number in the samples of water collected, but they gathered occasionally in quantities on the masonry walls of the gate chamber. In the autumn of 1897, masses of Spirogyra, Oscillaria, and Ulothrix collected there in mats. In April, 1898, Spirogyra, Ulothrix, and Stigeoclonium began to develop in thick masses on the wTalls; by the latter part of May, 1898, these algae had disappeared almost entirely. During the first week in June a species of Conferva developed luxuriantly. Heavy rains which fell on June 9 and 13, made the river water extremely muddy; and by June 16, 1898, the masses of Conferva had disappeared. During July, 1898, thin, but widely spread mats of an alga resembling Lyngbya papyrina developed on the walls of the gate chamber, and appeared in a few patches on the surface of the sand filters. In August, 1898, Spirogyra collected again in streamers in the gate chamber. After a period, during which the river wras clearer than usual, little mats of Spirogyra were found on the surface of the sand when the water was drawn off from Filters Nos. 1 and 2 in order to scrape. The other filter plants were under a roof, and algae did not appear at any time, either in the settling basins, or on the wooden walls of the filters, or on the sur- *"An Improvement in the Sedgwick-Rafter Method for the Microscopical Examination of Drinking Water." D. D. Jackson, Technology Quarterly, Vol. IX, December, 1896, p. 271, et seq. 350 APPENDIX NO. 4,-REPORT OF BACTERIOLOGIST. faces of the sand. During summer weather masses of mold, however, developed in the coagulant tubs both of the Warren and Jewell Filters. Among the other forms of microscopical life which were found, Diatoms were common, and, occasionally, species of Protozoa. Cells of Asterionella (variety gracillima) were found on several occasions in samples collected from the gate chamber, Highland Reservoir and Bed- ford Basin; also, during August and September, 1898, in great numbers in the Wilkinsburg Reservoir. During July, 1898, great numbers of cells of Dinobryon (variety sertularia) appeared in the samples of water collected in the Bedford Basin. The samples from this reservoir had an odor, at that time, which resembled raw oysters. Effluents from the sand filters and from the Warren and Jewell Filters were examined several times. No organisms were found in the filtered waters, except when the sand filters had just been scraped, and when an unsufficient amount of coagulant was being applied to the me- chanical filters. The remaining paragraphs contain short descriptions of the sources from which the samples were collected. Gate Chamber. Tire samples taken from the "Gate Chamber" were collected over the inlet of the 6-inch main. These samples were considered to be repre- sentative of the Allegheny River, because the 6-inch pipe leading to the filter plant branched from the rising mains, which passed directly from the Pumping Station to the Highland Reservoir. Settling Basin. The samples collected as representing the settled water were collected below the surface in a small well, through which this water passed just before flowing on to the surface of the sand filters. Effluents. The "Effluents" were collected from taps placed in the outlet pipes, as close to the filter basins as possible. Highland Reservoir. The samples marked "Highland Reservoir" were collected from two points. Those samples, which are marked "'Highland Avenue Main" were drawn from the water just after leaving the reservoir on the way to the main running down North Highland Avenue. The samples, which are marked "Butler Street Main" were taken from a platform directly over the point where this main leaves the Highland Reservoir. MICRO-ORGANISMS. 351 Herron Hill. The samples marked "Herron Hill" were collected from a platform directly over the point where the water passes out from the reservoir to the piping system. The water used in filling this basin is pumped from a main leading from Highland Reservoir. Bedford Basin. The samples marked "Bedford Basin" were collected a few inches under the surface near the place where the water leaves the basin on its way to the service pipes. This reservoir is filled by pumping from the same main as that from which water is pumped to Herron Hill Reservoir. South Side Reservoir. The samples marked "South Side Reservoir" were collected from a platform over the outlet main. The water in this reservoir is pumped directly from the Monongahela River. Wilkinsburg Reservoir. The samples marked "Wilkinsburg Reservoir" were collected a few inches under the surface of the water near the bank of the basin. The water in the reservoir is pumped from a crib which lies in the bottom of the Allegheny River. Crenothrix and large numbers of Asterionella were found on several occasions in this reservoir. The presence of these organisms indicates that the basin probably receives considerable ground water, at least at some seasons of the year. Lists of all the organisms found, together with the dates and sources from which the samples were collected, are given in the following tables. Respectfully submitted, Wm. R. Copeland, Bacteriologist. December 28, 1898. 352 APPENDIX NO. 4,-REPORT OF BACTERIOLOGIST. ALLEGHENY RIVER, Organisms Per Cubic Centimeter. Year. 1897. I 1898. Month. Aug. September. Oct. November. Dec. March. Day. 31 1 4 8 14 1 17 29 8 11 19 1 29 4 1 10 1 19 ' 26 PLANTS. 44 22 74 91 37 103 99 121 147 75 234 152 21 114 74 Diatomaceae 23 16 54 56 20 53 71 I 56 131 55 174 151 21 111 7? Amphora 0 0 1 2 0 2 0 0 12 4 6 ! o 0 Asterionella 0 0 0 0 0 0 0 0 0 0 0 0 0 Cocconema.... Cyclotella 0 o 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 3 0 1 0 0 0 0 0 0 i i ! o i 0 0 0 0 0 Cymbella 0 0 0 6 Diatom a 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Encyonema 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 Epithemia 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Eimotia 0 0 1 2 0 1 1 4 0 0 0 0 0 0 0 Fragilaria 0 0 0 0 0 0 0 8 0 0 52 0 1 1 0 Gomphonema 0 0 0 2 0 0 0 0 0 0 0 4 0 9 2 Melosira y 2 0 4 0 0 0 0 1 0 1 6 4 0 0 0 Navicula 21 10 32 47 7 42 62 42 101 29 40 82 16 80 54 Nitzschia 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Pleurosigma 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 Stauroneis 0 0 0 0 0 0 0 0 0 0 2 0 0 o 0 Stephanodiscus 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Surirella 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 Synedra 0 4 16 1 3 7 5 1 6 8 68 38 3 4 8 Tabellaria 0 2 0 2 0 1 0 0 24 1 0 0 0 7 2 Chlorophyceae 91 "4 20 34 15 49" 24~ 63 4" 20 22 2 0 2 2 Arthrodesmus 0 0 0 0 0 0 o 0 0 0 0 0 0 0 0 Chlorococcus 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Closterium 1 . 0 1 0 0 1 0 0 0 0 0 0 0 0 0 Cosmarium 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 Desmidium 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Dimorphococcus 0 0 0 0 0 0 0 0 o' 0 0 0 0 0 0 Euastr'um 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Micrasterias 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Palmella 0 0 4 9 4 21 3 62 0 18 20 0 0 0 0 Fandorina 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Pediastrum 1 0 0 2 0 0 0 0 0 1 0 0 0 0 0 Protococcus 1 2 5 7 4 4 1 0 0 1 0 0 0 0 0 Raphidium 0 0 1 0 0 0 7 0 0 0 0 0 0 0 0 Scenedesmus 12 2 9 14 6 22 11 1 4 0 0 0 0 0 0 Sphaerozosma 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Spirogyra 0 0 0 0 0 1 0 0 0 0 2 0 0 0 0 Staurastrum 0 0 0 2 0 0 0 0 0 0 0 2 0 0 0 Stigeoclonium 0 0 0 0 0 0 2 0 0 0 0 0 0 2 0 Volvox 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 Cyanophyceae 2 2 0 ~r 2 1 4 2 12 0 38 16 0 Zi 0 Chroococcus 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 Ccelosphaerium 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Conferva 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Dictyosphmrium 0 0 0 1 2 0 0 0 0 0 0 0 0 0 0 Leptothrix 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Lyngbya 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 M'ierocystis ; 0 0 0 0 0 0 0 0 0 0 32 0 0 0 0 Oscillaria Sirosiphon 0 o 2 0 0 o 0 o 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 0 0 0 0 0 0 Stephanosphaera 0 0 0 6 6 0 0 Ulothrix 2 0 0 0 0 0 3 2 0 0 6 14 0 1 0 Fungi 0 0 0 0 0 0 0 0 0 0 0 0 0 0 o' Crenothrix 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Saprolegnia 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 ANIMALS. 3 4 1 0 1 3 5 6 0 2 0 0 4 0 0 Protoxoa 3 4 1 0 1 3 5 6 0 2 0 0 4 (1 O' Dinobryon 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Euglena 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Monas 2 4 0 0 0 2 0 3 0 0 0 0 0 0 0 Paramaecium 0 0 1 0 1 0 3 2 0 2 0 0 1 0 o Peridinium 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 Tintinnus 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Vorticella 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Other Ciliata 0 0 0 0 0 1 2 0 0 0 0 0 3 0 0 Rhizopod a 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 OTHER ORGANISMS. 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Crustaceae 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1-0 Daphnia 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 MICRO-ORGANISMS. 353 ALLEGHENY RIVER, (Coot.) Organisms Per Cubic Centimeter. Year. 1898. Month. April. May. June. July. August. Sept. Day. 5 | 13 2 3 10 8 25 28 5 11 16 25 30 7 14 21 PLANTS. Diatomacese Amphora 32 31 52 49 155 151 150J 101 123 T 86 125 84" 56 40 _43_ 37 JO 32 raj go 14 i S' 92 66 98 60 _21_ 19 40 30 24 • 27 0 0 0 5 0 5 0 0 '2 0 0 0 2 2 1' 0 Asterionella 1 11 18 9 0 0 0 0 0 0 0 2 0 0 0 0 Cocconema 0 0 0 0 2 0 0 0 0 0 0 8 0 0 2 0 Cyclotella 0 0 3 0 0 0 0 0 0 0 0 0 0 0 0 0 Cymbella 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 0 Diatom a 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Encyonema 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Epithemia 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Eunotia 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Eragilaria 0 0 16 0 0 10 0 0 0 0 0 0 0 0 0 0 Gomphonema 0 1 2 0 0 2 0 0 4 0 0 4 0 0 0 0 Melosira 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Navicula 8 17 72 56 48 34 32 25 12 12 22 42 46 14 15 21 Nitzschia 0 0 0 0 0 6 0 0 0 0 0 0 2 0 1 1 Pleurosigma 0 0 0 3 0 0 2 1 0 0 0 0 2 0 0 0 StauroneD 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Stephanodiscus 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Surirella 0 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 Synedra 20 18 35 50 36 27 6 11 14 2 6 8 6 3 3 5 Tabeliaria Chlorophy cese 2 1 2 T 5 "T" 0 24 0 "15" 0 "4T 0 16 0 5 0 28 0 33 4 "26 0 20 0 34 0 2 2 13 0 3 Arthrodesmus 0 1 0 2 0 0 0 0 0 0 0 0 0 0 0 0 Chlorococcus 0 0 » 14 0 0 0 0 0 0 0 0 0 0 0 0 Closterium 0 0 . 1 1 0 0 0 0 0 0 0 0 2 0 0 0 Cosmarium 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 1 Desmidium 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Dimorphococcus 0 0 0 0 0 1 0 0 0 0 0 0 6 0 0 0 Euastrum 0 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 Micrasterias 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Palmella 0 0 2 0 5 0 0 0 16 14 6 0 4 0 0 0 Fandorina 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Pediastrum 0 0 0 0 0 3 4 0 0 2 2 2 4 0 0 0 Protococcus 1 0 0 5 4 25 4 3 12 9 10 12 12 1 4 1 Raphidium 0 0 0 0 0 1 0 0 0 0 0 0 0 0 2 0 Scenedesmus 0 0 0 0 4 7 8 1 0 2 6 4 4 0 7 0 Sphserozosma 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 S'pirogyra 0 0 0 0 0 0 0 1 0 0 0 0 2 0 0 0 Staurastrum 0 0 0 0 2 4 0 0 0 6 2 0 0 1 0 1 Stigeoclonium 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Volvox 0 0 0 1 0 0 0 0 0 0 0 0 0 0 o 0 Cyanophy cese ~0 ri- 1 3 "0" ro" "T 0 12 2 6 4 0 3 JT Chroococcus 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 Coelosphserium 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Conferva 0 0 0 0 0 0 0 0 0 12 2 2 4 0 i 0 Dictyosphserium 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Leptothrix 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Lyngbya 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 Microcystis 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Oscillaria 0 0 0 0 0 0 0 0 0 0 0 2 0 0 1 0 Sirosiphon 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 O' Stephanosphsera 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Ulothrix 0 2 1 2 0 0 0 0 9 0 0 2 0 0 1 0 S^ungi 0 0 0 0 0 "0" 0" T _o 0 0 0 0 0 0 0 Crenothrix 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Saprolegnia 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 ANIMALS. Protozoa 3 3 0 0 2 2 2 2 1 1 2 2 0 0 _0 0 12 12 2 2 J4_ 14 0 0 „2_ 2 _1 1 1 Dinobryon 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Euglena 1 0 1 0 0 0 0 0 0 2 2 2 0 0 0 0 Monas 0 0 1 2 0 0 2 0 0 4 o 4 o o Paramsecium Peridinium Tintinnus Vorticella 2 0 0 0 0 0 0 0 0 0 •0 0 0 0 0 0 1 0 0 0 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 0 2 0 o 6 0 0 o 1 0 0 o 0 0 0 o 0 0 0 Other Ciliata 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Rhizopod a 0 0 0 0 0 0 0 0 0 4 0 6 0 1 1 1 OTHER 0RGANISMS. 0 0 0 0 o' 0 0 0 0 0 0 0 0 0 0 0 Crustaceae 0 0 0 0 n 0 0 0 0 0 Q 0 0 0 0 0 o 1 0 0 • 1 0 0 0 0 0 0 0 4 0 0 354 APPENDIX NO. 4,-REPORT OF BACTERIOLOGIST. SETTLING BASIN. EFFLUENT, SAND FILTER No. 1. Organisms Per Cubic Centimeter. Year. 1898. 1897. 1898. Month. Aug. Sept. Oct. Aug. Sept. Oct. Nov. June. July. Day. 31 17 27 8 3 4 17 29 8 11 19 29 10 8 PLANTS. 15 115 110 103 0 0 19 4 14 9 0 5 2 0 Diatomacese 9 55 51 70 0 0 9 1 8 9 0 3 2 0 Amphora 0 1 0 0 0 0 1 0 6 0 0 0 o Asterionella Cocconema 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 o 0 Cyclotella 0 0 0 0 0 0 0 0 0 0 0 0 o Cymbella 0 0 0 0 0 0 0 0 0 0 0 0 0 Diatoma 0 1 0 0 0 0 0 0 0 0 0 o o Encyonema 0 0 0 0 0 0 0 0 0 0 0 o Epithemia 0 0 0 0 0 0 0 0 0 0 0 0 0 o Eunotia 0 1 0 0 0 0 0 0 0 0 0 () o Fragilaria 0 0 0 0 0 0 0 0 0 0 0 0 o Gomphonema Melosira 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 5 0 0 0 0 0 0 0 o Navicula Nitzschia 8 0 45 0 44 0 , 69 0 0 0 0 0 6 0 1 0 8 0 2 0 0 0 3 0 1 o 0 o Pleurosigma Stauroneis 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 o 0 o 0 o 0 Stephanodiscus 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Surirella 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Synedra 0 5 6 1 0 0 1 0 0 1 0 0 1 0 Tabei lari a 1 3 1 0 0 0 1 0 0 0 0 0 0 0 Chlorophyceae 6 58 53 33 0 0 10 3 R 0 0 2 0 o Arthrodesmus 0 0 0 0 0 0 0 0 0 0 0 0 0 o Chlorococcus 0 0 0 0 0 0 0 0 0 0 0 0 0 0 ■Closterium 1 0 0 0 0 0 0 0 0 0 0 0 0 0 Cosmarium 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Desmidium 0 0 0 2 0 0 0 0 0 0 0 0 0 0 Dimorphococcus 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Euastrum 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Micrasterias 1 0 0 0 0 0 0 0 0 0 0 0 0 0 Palmella 2 52 49 19 0 0 9 3 5 0 0 2 0 0 Fandorina 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Pediastrnm 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Protococcus 1 0 0 1 0 0 0 0 0 0 0 0 0 0 Raphidium 0 3 0 2 0 0 1 0 1 0 0 0 0 0 Scenedesmus 1 3 4 9 0 0 0 0 0 0 0 0 0 0 Sphagrozosma 0 0 o 0 0 0 0 0 0 0 0 0 0 0 Spirogyra 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Staurastrum 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Stigeoclonium 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Vol vox 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Cyanophyceae 0 2 6 0 0 0 0 0 0" 0 0 0 0 0 Chrooeoccus 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Ccelosphaerium 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Conferva 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Dictyosphaerium 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Leptothrix 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Lyngbya 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Microcystis 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Oscillaria 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Sirosiphon 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Stephanosphaera 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Ulothrix 0 2 6 0 0 0 0 0 0 0 0 0 0 0 Fungi 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Crenothrix 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Saprolegnia 0 0 0 0 0 0 0 0 0 0 0 0 0 0 ANIMALS. 1 10 0 1 0 0 2 0 0 0 2 0 0 0 Protozoa 1 10 0 1 0 0 2 0 0 0 9 0 0 n Dinobryou 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Euglena 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Monas . 1 2 0 1 0 0 2 0 0 0 0 0 0 0 Parameecium 0 8 0 0 0 0 0 0 0 0 2 0 0 0 Peridi nium 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Tintinnus 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Vorticella 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Other Ciliata 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Rhizopoda 0 0 0 0 0 0 0 0 0 0 0 0 0 0 OTHER ORGANISMS. 0 0 0 0_ 0 0 0 0 0 0 0 0 0 0 Crustaceae 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Daphnia 0 0 0 0 0 0 0 0 0 0 0 0 0 0 MICRO-ORGANISMS. 355 EFFLUENT, SAND FILTER, No. 2. WARREN FILTER. JEWELL FILTER. Organisms Per Cubic Centimeter. Year. 1897. 1898. 1898. 1898. Month. Aug. Sept. Oct. Nov. April. June. July. April. May. April. June. Day. 3 4 17 29 8 11 19 29 5 13 10 8 Clear 6 Cloudy 2 Clear 6 Clo 3 udy 10 PLANTS. Diatomacese Amphora 0 0 0 4 0 16 9 1 12 4 0 1 T 0 JL 0' 0 3 3 0 0 0 0 0 0" 0 0 Zo 0 1 1 0 0 _0_ 0 _ 0 _o_Z 0 72 _69_ 0 0 _0_ 0 84 56 2 36 IL 0 Asterionella 0 0 0 0 0 0 0 0 0 0 0 0 0 23 0 0 0 Coeconema 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Cyclotella 0 0 1 0 0 0 0 0 0 0 0 0 0 3 0 0 0 Cymbella 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Diatoma 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Encyonema 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Epithemia 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Eunotia 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Fragilaria 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Gomphonema 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Melosira 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Navicula 0 6 6 4 1 0 0 0 0 0 0 0 0 29 0 24 11 Nitzschia 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Pleurosigma 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Stauroneis 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Stephanodiscus.. 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Surirella 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Synedra 0 0 1 0 0 0 3 0 0 0 1 0 0 13 0 30 19 Tabellaria 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 Chlorophyceae. . Arthrodesmus 0 0 28 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 _6 0 Chlorococcus 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 9 4 Closterium 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Cosmarium 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 Desmidium 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Dimorphococcus 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 Euastrum 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Micrasterias 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Palmella 0 0 3 1 0 0 0 0 0 0 0 0 0 0 0 0 0 Fandorina 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Pediastrum 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Protococcus 0 1 0 4 0 0 0 0 0 0 0 0 0 0 0 18 1 Raphidium 0 0 2 3 0 0 0 0 0 0 0 0 0 0 0 0 0 Scenedesmus 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Sphaerozosma 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Spiro gyra 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Staurastrum 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Stigeoclonium 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Vol vox Cyanophycese.... Chroococcus 0 0 0 0 Zo 0 0 Z2 0 0 0 0 0 0 0 0 0 0 0 0 0 _0 0 0 0 Zo 0 0 ~F 0 ZZo 0 0 ■ 0 0 0 _0_ 0 0 Z3Z 0 0 ZZEZ 0 0 ZE 6 0 ZE 0 Coelosphaerium... 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Conferva 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Dictyosph aerium 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Leptothrix 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Lyngbya 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Microcystis 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Oseillaria 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Sirosiphon 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Stephanosphaera 0 0 0 0 0 0 0 0 0 0 0 0 0 0 II 0 0 _ Ulothrix . .......... Fungi Crenothrix 0 0 0 0 0 6 2 Zo 0 0 0 0 0 ZZOZ 0 0 Zo o' 0 ZE 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0" 0 0 Zo Z 0 3 0 0 0 ZZEZ 0 0 0 0 0 ZE 0 Saprolegnia 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 ANIMALS. Protozoa Dinobryon 1 ■ 1 0 0 (L 0 3 _3 0 0 _0 0 __0_ 0 0 1 1 0 0 0 0 0 0 0 0 0 0 _0_ 0 0 0 _0_ 6 0 O' 0 __0_ _0- 0 2_ 2 0 0 _0 0 1 1 0 1 1 0 Euglena 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 Monas 0 0 1 0 0 1 0 0 0 0 0 0 0 2 0 0 0 Paramaecium 1 0 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Peridinium 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Tintinnus 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Vorticella 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Other Ciliata 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Rhizopoda 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 OTHER ORGANISMS. Crustaceae Daphnia- 0 0 0 0 0 0 0 0 0 0 0 0 =0_ _oZ 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 0 -0_ 0 0 0 0 0 __0_ 0 0 0 0 0 _0_ 0 0 0 0 0 _o' 0 356 APPENDIX NO. 4,-REPORT OF BACTERIOLOGIST. HIGHLAND RESERVOIR, HIGHLAND AVE. MAIN. HIGHLAND RESERVOIR, BUTLER ST MAIN. Organisms Per Cubic Centimeter. Year. 1898. 1898. Month. Apr. July. August. September. July August. September. Day. _14_ 16 28 5 12 17 25 1 8 14 21 28 5 12 17 25 1 8 14 21 PLANTS. 34 39 35 28 26 44 62 54 29 28 22 14 36 24 52 48 32 24 22 9 Diatomaceae 34 7 24 16 12 32 46 30 14 26 15 10 16 12 0 20 14 14 16 18 4 Amphora 0 0 0 4 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Asterionella 7 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 3 0 Cocconema 1 0 0 0 0 0 2 0 0 1 0 0 0 0 0 0 0 0 0 0 Cyclotella 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Cymbella 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 0 Diatoma 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Encyonema 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Epith emia 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Eunotia 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Fragilaria 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 5 0 0 Gomphonema 0 2 0 0 0 4 0 0 0 1 0 0 0 0 0 0 0 0 0 0 Melosira 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Navicula 14 5 18 2 12 28 30 14 12 16 15 6 12 12 18 14 10 6 12 0 Nitzschia 0 0 0 0 0 0 4 4 0 4 0 0 0 0 0 0 0 0 2 3 Pleurosigma 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 Stauroneis 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Stephanodiscus.. 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Surirella 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Synedra 12 0 6 10 0 0 10 12 1 4 0 4 4 0 2 0 2 3 0 1 Tabellaria 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 Chlorophycese.... "0" 32 11 8 8 10 12 22" 10 2 7 3 18 8 30 34 18 7 4 4 Arthrodesmus .... 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 b 0 Chlorococcus 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 Closterium 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 1 0 0 Cosmarium 0 0 0 0 0 0 2 0 0 1 1 0 0 0 0 0 0 1 0 0 Desmidium 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Dimorphococcus 0 0 0 2 0 0 0 0 0 0 1 0 0 0 2 0 0 0 0 0 Euastrum 0 0 0 0 0 0 0 0 0 0 0 0 o 0 0 0 0 0 0 Micrasterias 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Palm el 1a 0 21 8 0 0 0 0 0 0 0 0 0 18 2 10 20 0 0 0 0 Fandorina 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Pediastrum 0 0 0 0 0 0 2 4 0 0 1 1 0 0 0 0 0 1 1 0 Protococcus 0 10 0 4 6 6 2 12 8 1 3 0 0 6 10 8 6 4 0 4 Raphidium 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Scenedesmus 0 1 3 0 0 2 6 4 1 0 0 1 0 0 6 2 12 0 2 0 Sphterozosma Spirogyra 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Staurastrum 0 0 0 2 0 2 0 2 0 0 1 1 0 0 2 2 0 0 1 0 Stigeoclonium ... Volvox 0 0 0 0 0 0 0 0 0 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Cyanophyceae 0 "O' 0 4 6 2 4 2 5 0 0 1 2 4 2 0 0 1 0 1 "Chroococcus 0 0 0 0 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Ccelosphaerium. ... Conferva 0 0 0 0 0 0 0 4 0 4 0 2 0 2 0 0 0 2 0 0 0 0 0 0 0 2 0 4 2 0 0 0 0 0 1 0 0 0 1 0 Dictyosphserium Leptothrix 0 0 0 0 0 0 0 0 2 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Lyngbya 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Microcystis 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Oscillaria 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Sirosiphon 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Stephanosph sera Ulothrix 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 2 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0_ Fungi o 0 0 0 6 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Crenothrix 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Saprolegnia 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 ANIMALS. 1 4 1 0 0 6 2 18 3 4 5 1 4 2 4 10 46 2 0 JL Protozoa 1 4 1 o (1 6 2 18 3 4 5 1 4 2 4 10 46 2 0 0 Dinobryon 0 0 0 0 0 0 0 6 1 0 0 0 0 0 0 0 0 0 0 0 Euglena 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 2 0 1 0 0 Monas 1 0 0 0 0 0 0 0 0 0 3 0 2 0 0 4 0 0 0 0 Paramtecium 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 Peridinium 0 0 0 0 0 0 0 2 0 0 0 0 0 0 0 o 0 0 Tintinnus 0 0 0 0 0 0 0 0 0 0 0 0 2 2 0 0 0 0 0 0 Vorticella 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 Other Ciliata 0 4 0 0 0 0 0 0 0 3 0 0 0 0 0 0 2 0 0 0 Rhizopod a 0 0 0 0 0 6 2 10 2 1 1 0 0 0 4 4 42 1 OTHER ORGANISMS. n 0 0 0 .0 2 0 0 1 0 0 0 0 0 0 0 0_ 1 0 J Crustaceae n 0 0 I 0 0 2 0 0 1 0 0 0 0 0 0 0 0 1 0 0. Daphina 0 0 0 0 0 2 0 0 1 0 0 0 0 0 0 0 0 1 _ 0 MICRO-ORGANISMS. 357 HERRON HILL RESERVOIR. BEDFORD BASIN. Organisms Per Cubic Centimeter. Year. 1898. 1898. Month. Day. July. 18 I 27 5 Aug 12 ust 18 25 Septem 1 1 9 ber. 14 Ju 18 ly- 27 5 Aug 12 ust. 18 25 ; Sep 1 tember. 9 14 PLANTS. Diatomaceae. Amphora 75 J 5. 0 66 40 0 36_ 24 6 46 _4 0 96 26 0 36 30 0 34 10 0 112 86 0 29 22 0 68 J4_ 0 54 24 0 46 40 0 68 30 0 47 14 0 63 IL 0 28 _4 0 82 32 0 22 J3 0 Asterionella 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 Cocconema 0 0 0 0 0 0 2 4 0 0 0 0 0 0 i 0 0 0 Cyclotella 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Cymbella 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Diatoma 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Encyonema 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Epithemia 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Eunotia 0 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 0 0 Fragilaria 0 0 0 0 0 0 0 40 0 0 0 0 0 0 0 0 6 0 Gomphonema 0 0 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Melosira 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Navicula 4 20 12 4 24 28 6 36 14 14 14 16 16 6 13 4 16 6 Nitzschia 0 2 0 0 0 0 0 0 4 0 0 18 6 8 12 0 7 6 Pleurosigma 0 0 0 0 0 0 0 2 0 0 0 0 0 0 0 0 2 0 Stauroneis 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Stephanodiscus 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Surirella 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Synedra 10 18 4 0 2 2 2 4 4 0 10 4 8 0 1 0 X 1 0 Tabellaria......... Chloropiiyceee 1 60 0 26" 0 10 0 3S 0 68 0 6 0 18 0 14" 0 5 0 52 0 25 0 "T 0 18" 0 15 0 14 0 16 0 30 0 ZE Arthrodesmus 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Chlorococcus 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Closterium 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Cosmarium 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 0 Desmidium 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Dimorphococcus 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Euastrum 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 Micrasterias 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Palmella 35 0 2 18 54 4 0 0 0 30 6 2 14 3 0 0 0 0 Fandorina 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Pediastrum 2 0 0 4 0 0 2 0 0 0 0 0 0 2 0 2 1 0 Protococcus 19 24 6 10 12 0 16 18 5 22 15 2 18 15 16 10 23 5 Raphidium 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 4 0 Scenedesmus 1 0 0 0 2 0 0 4 0 0 4 0 4 3 5 2 2 0 Sphserozosma 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Spirogyra 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Staurastrum, 1 2 2 2 0 2 0 2 0 0 0 0 2 0 0 2 0 0 Stigeoclonium 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Volvox 0 0 0 2 0 0 0 0 0 0 0 0 0 0 1 0 0 0 Cyaupphycese Chroococeus ro 0 _o_ 0 2 0 _6 2 _2_ 0 JL 0 6 0 2 0 2 0 2 2 _L 5 ~2 0 zs: 0 ZE 0 12 1 8 0 10 2 ZE . 2 Coelosphserium 0 0 2 0 2 0 0 2 1 0 0 0 0 i i 0 0 0 Conferva 0 0 0 2 0 0 6 0 0 0 0 2 0 3 8 8 18 2 Dictyosphaerium 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Leptotbrix 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Lyngbya 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 Microcystis 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 Oscillaria 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Sirosiphon 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Stephanosphsera 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 0 0 0 Ulothrix Fungi Crenothrix 0 0 0 0 0 0 0 ZE 0 2 Jo 0 0 0 0 0 0 0 0 T 0 0 0 1 ZE 0 0 ~E 0 0 "T 0 0 nr 0 0 0 0 0 0 0 0 T 0 0 Jo 0 0 Jo 0 0 ZE o Saprolegnia 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 ANIMALS.^ Protozoa 5 5 32 32 4 4 10 10 24 24 4 4 J6_ J6 10 10 37_ 37 । 324 324 1256 376 1256 376" 40 40 8 8 1 7 _16 16 19 19 3 3 Dinobryon 0 24 0 0 0 0 0 0 0 306 1252 374 26 1 0 0 0 0 Euglena 2 2 0 0 2 2 2 0 0 10 1 0 4 0 3 6 18 0 Monas 1 6 0 0 10 0 0 2 0 0 1 0 10 2 0 2 1 1 Paramaecium 0 0 0 0 10 0 0 2 1 4 1 0 0 1 0 0 0 0 Peridinium 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 2 0 0 Tintinnus 0 0 0 8 0 0 0 0 0 0 0 0 0 1 2 0 0 0 tortieella 0 0 0 0 0 0 2 0 33 0 0 0 0 0 1 0 0 0 Other Ciliata 2 0 4 Q 0 2 0 0 0 4 1 2 0 2 0 0 0 0 Rhizopod a 0 0 0 0 2 0 12 6 3 0 0 0 0 0 1 6 0 ' 2 0THER ORGANISMS. Crustaceae Daphnia _0 _0 ro 0 0 0 0 0 0 0 0 0 0 0 0 0 _0 0 0 _0 0 2 ' r 1 4 _0 0 0 0 JO 0 0 4 _0 0 0 0 0 0 0 4 0 4 _0 -0 0 _o_ 0_ 0" 358 APPENDIX NO. 4,-REPORT OF BACTERIOLOGIST. SOUTH SIDE RESERVOIR. WILKINSBURG RESERVOIR. Organisms Per Cubic Centimeter. Year. 1898. 1898. Month. July. August. September. July. August. September. Day. 16 I 25 5 18 25 l| 1 9 14 18 1 27 13 18 26 1 9 14 PLANTS. 81 30 58 18 34 4 21 6 52 94 22 90 31 54 3881212 Diatomacese 11 2 12 8 22 2 6 2 24 76 8 11 7 31 2061163 Amphora 2 0 0 0 0 0 0 0 oo o o i o o o Asterionella 0 0 0 0 0 0 0 0 0 0 0 1 0 30 19311156 Cocconema 0 0 2 0 0 0 0 I 1 0 0 0 0 0 0 0 0 Cyclotella 0 0 0 0 0 0 I 0 1 0 0 0 000 000 Cymbella 0 0 II 0 0 0 0 0 10 0 | 0 0 0 0 0 0 0 Diatoma 0 0 || 0 0 0 0 0 0 0 | 0 000 0 00 Encyonema 0 0 0 0 0 0 0 0 0 0 000 000 Epithemia 1 0 0 0 0 0 0 0 0 0 i 0 0 0 0 0 0 Eimotia 0 1 0 II 0 0 0 0 0 0 00'000 000 Fragilaria 0 0 0 0 0 I 0 0 0 0 71 | 0 0 0 6 i 6 0 Gomphonema 1 0 0 0 2 I 0 I 0 0 0 0 | 2 1 0 0 0 0 Melosira 0 I 0 0 0 0 0 ! 0 0 7 0 0 0 0 0 0 0 Navicula 5 I 2 10 6 14 2 I 6 1 2 5 6 4 2 1 7 4 Nitzschia 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 Pleurosigma 0 0 0 0.0 00 0 0 | 0 000 001 Stauroneis 0 0 0 0 0 0 । 0 0 0 0:0 0 0 6 0 1 0 Stephanodiscus 0 0 0 0 0 0 I 0 0 0 0 0 0 0 0 । 0 : 0 Surirella 0 0 0 0 0 0 I 0 0 o olo 0 0000 Synedra 2 0 0 2 6 0 0 0 14 0l0 5 1 0 0 1 Tabellaria 0 0 0 0 0 0 0 0 1 0 i 0 0 3 1 0 0 2 Chloropliyceae 63 24 44 10 12 2 12 1 21 3 14 65 13 I 6 I 4 30 Arthrodesmus 0 0 0 0 0 0 0 0 00 000 0 0 0 Chlorococcus 7 0 0 0 0 0 0 0 o o | o o o 000 Closterium 0 1 2 0 0 0 0 0 0 1 0 0 0 | 0 1 0 | 0 | 0 Cosmarium 0 0 0 0 2 0 I 0 0 1 0 0 0'0 0 । 0 i 26 Desmidium 0 I 0 II 0 0 0 0 0 0 0 0 0 0 0 1 0 1 0 0 Dimorphococcus 0 0 0 o o o o o 0 1 0 । 0 0 0 0 0 0 Euastfum 0 0 0 0 0 0 I 0 0 00 000 000 Micrasterias 0 0 0 0 0 0 0 0 00 000 0 1 0 0 Palmella 40 0 40 10 10 0 0 0 17 0 8 39 0 0 0 0 Fandorina 0 0 0 0 0 0 0 0 0 0 1 2 1 0 0 0 0 Pediastrum 5 0 0 0 0 0 0 0 0 0 0 0 111 0 0 Protococcus 10 14 4 0 0 2 12 1 0 0 2 23 10 3 3 Raphidium 0 0 i 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Scenedesmus 0 6 I 0 0 0 0 0 0 1 1 0 0 0 jl 1 1 1 Sphserozosma 0 0 | 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Spirogyra 0 0 0 0 0 0 1 0 0 olo 0 o olo 0 0 Staura'strum 1 2 0 0 0 0 I 0 0 0 0 1 0 1 0 0 0 0 Stigeoclonium 0 0 0 0 0 0 I 0 0 0 1 0 0 0'0 0 0 Volvox o I 0 II 0 0 0 0 1 0 0 112 12 10 1 Cyanophycese Trq £ 0 0 0 2 3 3 14 0 6 rrl 9 175 16 Chroococcus 0 0 0 0U 0 0 0 0 0 0 0 5 o 0 0 Coelosphaerium o 1 0 | 0 0 0 0 I 0 0 0 12 | 0 6 0 0 1 15 Conferva 0 0 0 0 0 0 1 2 2 1 0 0 0 19 174 0 Dictyosphaerium 0 0 0 0 0 0 I 0 II 0 0 0 0 0 0 0 0 Leptothrix 0 0 0 0 0 0 0 0 110 0 0 0 0 olo Lyhgbya 0 0 1 2 0 0 0 0 0 oil 000 000 Microcystis o | 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Oscillaria 0 0 0 0 0 0 0 0 0 0 000 000 Sirosiphon 0 I 0 1 0 0 0 0 0 0 o | o o o olio 0 0 Stephanosphaara 0 0 0 0 0 0 I 0 0 0 | 0 0 0 0 || 0 0 0 Ulothrix..? 7 I 4 0 0 0 0 1 I 1 o | o | o o o || o | o i Fungi 0 0 0 0 0 0 1 0 4 1 O' 8 I 6 I 8 3 3 Crenothrix 0 0 0 0 0 0 1 0 4 | 0 0 | 8 6 I 8 | 3 Saprol egni a 0 1 0 0 0 0 0 0 0 oil o o 61| o o 6 ANIMALS. 5 0 2 4 4 6 8 0 10 0 15 34 217 8 5 Protozoa 5 0 2 4 4 6 8 | 0 10 0 15 34 217 8 5 Dinobryon 0 0 0 0 0 0 1 0 0 0 0 0 12 183 0 ii Euglen'a 0 0 0 0 0 0 1 0 0 0 0 0 1 17 0 1 Monas 0 0 2 0 0 2 6 0 0 0 0 14 0 0 1 2 Paramrecium 10 0 2 0 0 0 0 0 0 001 000 Peridinium 0 0 0 0 0 0 0 0 0 0 0 0 0 10 1 6 2 Tintinnus 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Vorticella 4 0 0 0 0 0 0 0 0 0 0 0 1 | 0 1 0 Other Ciliata 0 0 I 0 0 0 0 0 0 10 0 1 4 0 0 0 Rhizopod a 0 0 0 2 1 4 I 4 0 1 0 0 0 0 0 15 7 0 0 OTHER ORGANISMS. 0 0 II 0 0 I 0 I 0 0 0 1 1 | 0 0 1 0 0 1 Cnistaceae 0 0 0 0 | 0 0 0 0 1 I 1 0 0 1 0 0 1 Daphnia 0 0 0 0-0 0 0 ol 1 I 1 II 0 0 1 >! 0 0 1 APPENDIX No. 5. Report upon Driven Well Supply. E. M. Bigelow, Esq. Director of Department of Public Works. Dear Sir: In accordance with your instructions; in order to ascertain whether it was possible to secure a supply of ground water at our Brilliant Pump- ing Station, in sufficient quantities and of proper quality for supplying the city by means of driven wells, I beg to report that the contract was let for driving a six-inch well, that is, five and five-eighths inches, inside, and the work was commenced early in May. We located this well at the south corner of the building, and about fifty feet from the river's edge. The accompanying blue print1 will show you the character of the materials through which the well went, and also the amount of water secured at the different depths. You will notice by the accom- panying analyses2 that the water in the sand stone was of a good quality, and by reference to the blue print1 you will find that the quantity was such that it would take something like six hundred wells, to give us our present supply of water, assuming that they would all have the same flow as this one well, which is very doubtful. Although, as I stated above, the water is of good quality, you will notice it is very hard and could not be used for steam making purposes, and would probably be disagreeable for ordinary washing. Farther down, the quantity of water remained about the same, but the character of it became worse when the slate was struck. It carried a large quantity of gas and was very disagreeable to the taste and smell. At the extreme bottom it was quite salty, and the result of the experiment seems to be that the idea of securing a supply of water in that neighborhood in this manner is entirely impracticable. Yours respectfully, A. B. Shepherd, Superintendent, Bureau of Water Supply and Distribution. July 16, 1897. 1 Reproduction of the blue print given opposite this page. 2Results of analyses will be found in Appendix No. 2, Page'3i6. P late No. gl. TEST WELL AT BRILLIANT PUMPING STATION LEVEL OF BOILER HOUSE FLOOR CINDERS FILLED MATERIAL RED CLAY & LOOSE SHALE AVERAGE HEIGHT OF WATER IN RIVER MAY 24.1897 CAPACITY AT THIS DEPTH 612 GALLONS PER HOUR LOOSE SHALE & SMALL AMOUNT OF GRAVEL. MEDIUM SOFT SHALE MAY 26.1897 CAPACITY ATTHIS DEPTH - 3060 GALLONS PER HOUR MAY 28,1897 CAPACITY ATTHIS DEPTH 5049 GALLONS PER HOUR MAY 31, 1897 CAPACITY ATTHIS DEPTH 4370 GALLONS PER HOUR STRATIFIED SANDSTONE VARIOUS COLORS JUNE 9, 1897 CAPACITY AT THIS DEPTH 4-968 GALLONS PER HOUR BLACK SLATE GRAY SLATE WATER CHARGED WITH GAS JUNE 10, 1897 CAPACITY ATTHIS DEPTH 5562 GALLONS PER HOUR. APPENDIX No. 6. Financial Statement. Appropriation No. 46,-Dated February 1, 1899. CLASSIFICATION OF EXPENDITURES. Consultation Salaries $ 5,249 93 Salaries of Office and Laboratory Force 13,188 08 Wages of Filter Attendants, Mechanics and Laborers 5,144 81 Furniture, Apparatus and Fixtures 697 57 Material and Supplies for Office and Laboratory I,323 70 " " " Sand Filters 1,546 59 " Filter Building and Filters within 2,987 61 " " " Boiler Experiment 1,241 39 Surveys 923 78 Office and Traveling Expenses of Employees 1,716 54 Total $34,020 00 DISTRIBUTION OF EXPENDITURES. Construction and Installation. Office and Laboratory $1,100 57 Sand Filters 2,771 13 Filter Building 815 33 Warren Filter 1,206 46 Jewell " 1,305 88 Worms Tile Filter 676 90 Boiler Experiment 693 71 Total $8,569 98 Maintenance and Operation. Engineering Administration $12,612 56 Analyses of River, Crib, and Tap Waters 1,563 82 Miscellaneous Analyses 290 26 Species and Micro-Organism Work 409 00 Attendance and Analyses, Sand Filters 2,769 85 " " Warren Filter 1,810 14 " " Jewell " 1,613 02 " " Worms Tile Filter 1,198 12 Studies for Filter Sites 749 61 Gravity Supply Study • 437 53 Boiler Experiment I,I99 54 Sanitary Investigations 421 32 Miscellaneous Studies 375 25 Total $25,450 02 Total Expenditures $34,020 00 In addition to this amount, there has been expended by the Bureau of Water Supply and Distribution, the following sums :- Drilling Test Well at Brilliant $ 282 56 Laboratory Fixtures and Apparatus 1,012 87 Supplies for Filter Building and Filters within 1,421 21 Teaming, Expressage, Etc 139 74 Labor at Brilliant 1,868 80 Total $ 4,725 18 362 APPENDIX NO. 6. FINANCIAL ST A TEMENT-Continued. There are also unpaid bills to the account of appropriation No. 46, as follows:- CLASSIFICATION. Consultation Salaries $ 00 Boiler Experiment . 145 25 Traveling Expenses of Employees 150 92 Total $ 2,266 17 DISTRIBUTION. Construction and Installation. Boiler Experiment $ 145 25 Total $ 145 25 Maintenance and Operation. Gravity Supply Study $ 1,539 57 Sanitary Investigations 581 35 Total $ 2,120 92 Total Amount Unpaid $ 2,266 17 INDEX. PAGE. Absorption of alumina, see Mechanical filters, see also Sulphate of alumina. " " oxygen, see Dissolved oxygen. Acidity of media, see Media. Acknowledgment of courtesies 116 Agar, litmus lactose and nutrient glycerine 334 " used for plating 334 " Wurtz litmus 328 Agreements with filter companies Ill Agitator, see Jewell and Warren Filters. Agitating, surface of sand, see Jewell Filter, trailing. Air valves, see Indian Creek, conduit. Albuminoid ammonia, see Ammonia. Algae, found in samples of waters 349, 352 Alkalinity, method of determining 230 " of media, see Media " of samples of waters 238 Allegheny City tap, analyses of samples from 282 " " water works, description of, and samples from 278 Allegheny River:- Analyses of samples from 237 At Brilliant, analyses of samples from 234 " Etna, " " " 11 299 " Hulton, " " " " 285 " Kittanning, " " " " 321 " Millvale, " " " " 305 " Montrose, " " " " 278 " Sharpsburg, " " " " 298 " Wildwood, " " " " 292 Character of water supply derived from 16 Drainage area of. 30 Intake at Brilliant 238 List of cities and towns upon 30 Rapidity of flow and lack of self-purification 18 Samples from, analyses of 237 Sanitary condition of supply drawn from.. 30 Special samples from 243 Allegheny River Water:- Alkalinity of. 57 Amount of calcium carbonate in 57 Analyses of samples of 237 Bacteria in, daily results 127, 172, 194, 207 " " monthly averages 39 " species found in 346 Calcium carbonate in 57, 63 Character of. 232 364 INDEX. PAGE. Allegheny River Water,-Con:- Composition of. 33 " " before and after settling and after filtration 39, 43 Healthfulness of 27 Lime in, see Calcium carbonate Micro-organisms found in 352 Mineral analysis of 243 Samples of, analyses of 237 Special samples of. 243 Species of bacteria found in 346 Allegheny water works, see Allegheny City water works, see also Montrose. Alum, Alumina, see Sulphate of alumina. Alumina, method of determining 231 Aluminum foil, used in determining nitrates 228 American filters, see Mechanical filters. " Public Health Association, reference to 344 11 system of filtration, see Mechanical filters. Ammonia, in samples 237 " method of determining 226 Analyses, cost of. 361 of samples 237 " sand 121, 157, 183 Analysis, Committee on Water 1 Animals, list of, found in samples 352 Annual charges for gravity supply and filtration 84 see also Charges, Depreciation, Interest and Sinking fund. Antwerp, visit to 3 Appendices to report of Resident Engineer, list of. 117 " title page of 221 Aqueduct, see Indian Creek. Area, see Drainage area. " of sand surface, see Jewell, Sand and Warren Filters. Arrangements with filter companies Ill Asbestos, use of with sand filters 70, 115 Assistants employed, list of 119 Asterionella, found in samples 350, 352 Atlanta, use of meters in 77 Atmospheric dust, as a source of typhoid fever 12 Attendants, list of filter 117 Autoclave, use of 335 Auxiliary supply, reference to in report of Consulting Engineer 71 " " report of Commission upon 6 Bacilli, list of 327 Bacillus, coli communis, tests for 348 " prodigiosus, test with 345 Bacteria, growth in underdrains 60 ' in effluents, see also Jewell, Sand, Warren, and Worms Tile Filters. " method of examination for 331 " numbers of, in samples 237 " species of, found in samples 344 Bacterial efficiency, sec Jewell, Sand, Warren, and Worms Tile Filters, see also Cribs INDEX. 365 PAGE. Bacteriological analyses, reference to 38 " and Microscopal Investigations, report upon 325, 331 Bacteriologist, reference to 2, 16, 21, 38, 110, 116 " report of, Dr. Eugene Wasdin 325 " " " Wm. R. Copeland 331 Barium chloride, used in determining sulphuric acid 230 Basin, see Sedimentation, Settling, and Storage Basins. see also Indian Creek and Squaw Run Bay City, use of meters in 77 Beck's Run, analysis of sample of Monongahela River from 319 Bedford Basin, bacterial examination of samples from 330 " " micro-organisms found in samples from 357 Bennett Water Company, see Millvale. Berkefeld Filter Company, proposition from 112 see also Domestic and Household filters. Berlin, visit to " use of meters in 76 Bigelow, E. M., reference to 3, 109, 112 " " report to, on Driven Well Supply 360 Biggs, Geo. W., Jr., reference to 116 Bills unpaid 361 Biological laboratory 110, 114, 323, 327 Biologist, see Bacteriologist. Blow-offs, see Indian Creek, conduit. Boilers, estimated cost of 65 Boilers, experimental:- Analyses of scales 217 " " water 314 Burners under 216 Calcium in scale : 217 Comparison of effect of different waters 63 Condition of and conclusions about 219 Cost of experiments 361 Dimensions of. 216 Expert's opinion about condition of 218 Gas supply 216 Injectors 217 Lime, see Calcium Oil Well Supply Company, reference to 115, 216 " " report by, on condition of 218 Reference to 63 Scale 217 Supply of water 216 Bonds, issue of, recommended 7 Boston, Mass., rainfall near 92 " " typhoid fever death rate in 11 Bottles, for collection of samples 225 Bremen, visit to 3 Brilliant, driven well at, analyses of samples from 316 " reference to experimental filter plant at 141 366 INDEX. PAGE. Brilliant, samples from Allegheny River at 237 Brockton, use of meters in 77 Brown, Wm. R., City Engineer, reference to 112 Bureau of Health, laboratory of 110, 327, 333 " " Water Supply and Distribution, money expended by 361 Burners, see Boilers, experimental. Butler Street Main, see Highland Park Reservoir. Calcium carbonate, action of, in water on sulphate of alumina 57 " " in sands, see Chemical analyses of. Capacity of basin, see Jewell, Sand, Warren and Worms Tile Filters, see also Indian Creek and Squaw Run. Castleman's River, analyses of samples from 323 " " as a gravity source 80 Carbonate of lime, see Calcium carbonate. Carbonate of magnesium, see Boilers, experimental, scale. Caustic permanganate, used in ammonia determinations 226 Celery, as a source of typhoid fever 12 Census of Pittsburgh, reference to 22 Chains, see Jewell Filter. Chairmen of Commission and of Committees 1 Channels in sand, see Sand filters. Chapters to report of Resident Engineer, list of 117 Character of, Allegheny River water 30 " " Monongahela River water 32 " " present water supply 3, 30 " " water supplied to South Side 15, 31, 32 Charges, annual, for gravity supply and filtration 84 see also Annual charges, Depreciation, Interest and Sinking fund. Charts, see Diagrams. Cheat River, as a gravity source 80 Chemical analyses, methods of 225 " " reference to 38, 109 Chemical analyses of, Allegheny and Monongahela Rivers 33 see also Allegheny and Monongahela Rivers, composition of " " effluents, filter effluents, see Jewell, Sand, Warren and Worms Tile Filters. " " river sands 120, 121 " " river waters 33 " " samples 233 " " sand in sand filters 122 " " scale 217 Chemist, reference to 2, 38, 109, 116 " report of, methods of chemical analyses and discussion of results 223 " " " reference to., . 109 Cherry Alley, analyses of samples from 244 Chestnut Ridge, reference to 89, 98 Chezy formula, reference to 100 Chlorine, cause of, in river waters 233 " in samples of water 237 " method of determining 228 INDEX. 367 PAGE. Chlorophycese, list of, found in samples 352 Cincinnati, Ohio, visit to 2 City Engineer, reference to 112 City samples, analyses of miscellaneous 318 " " bacterial examination of 325 City taps, analyses of samples from, see Allegheny, Etna, Millvale, Sewickley, Sharpsburg, South Side, Verona and Wilkinsburg. City water, bacterial examination of 325 Cities, American, use of water in 95 " and towns, list of, upon the Allegheny River 30 " " " " " " " Monongahela River ; 32 " using meter system 76 " using sand filters 5 " visited 2, 3 Clarification, amount of sulphate of alumina required to produce 55 Clay, see Turbidity. Cleaning of filters, see Jewell, Sand, Warren, and Worms Tile Filters. Clearness of effluents, comparison of, with sand and mechanical filtration 61 see also Jewell, Sand, Warren, and Worms Tile Filters. Coagulant, absorption of, by muddy waters 54 " explanation of use of 36 " use of other, than sulphate of alumina 70 " variation in rate of application of, see Jewell and Warren Filters. see also Jewell, Mechanical, Warren, and Worms Tile Filters; also Iron chloride and Sulphate of alumina. Coagulant pump, see Jewell and Warren Filters. Coagulation, absorption of sulphate of alumina without producing 54 Coal, see Indian Creek. Coal lands, difficulty in crossing, see Indian Creek, conduit. Coefficient of conduit discharge. 100 see Indian Creek, tunnel and conduit. see also Uniformity coefficient. Coli communis, Bacillus, tests for 348 Collection of samples 225 Colonies developed by growth of different days 338, 339 " in media of different reactions 340 Colon group of bacteria 328 Color, in river water due to what 62, 232 " method of determining 223 " of samples of waters 237 " of waters used in eastern cities 62 " removed, comparison of, by sand and mechanical filters 62, 232 Commission, duties, organization and report of 1 " resolution creating iii " visits by 2, 116 Committees, list of 1 Companies, see Filter companies. Comparative cost of, gravity supply and filtration 82 " " sand and mechanical filters 4 Composition of Allegheny and Monongahela Rivers 33 " effluents, see Jewell, Sand, Warren, and Worms Tile Filters. 368 INDEX. ' PAGE. Comte Fils gelatine 334 Conclusions, of Commission 3, 7 " of Consulting Engineer 85 " of Prof. Wm. T. Sedgwick 23 " upon gravity supply 105 Conditions under which experiments were conducted Ill Conduit, see Gravity supply, Indian Creek and Laurel Hill Creek, conduit. see also Cost and Estimates. Conemaugh River, as a gravity source 80 Conferva, found in samples 349, 352 Confluence, rainfall at 92 Connellsville, reference to 80 Constituents, see Allegheny and Monongahela Rivers and Settled water, composi- tion of. see also Jewell, Sand, Warren, and Worms Tile Filters; also Chem- ical analyses. Construction of filters, cost of. 64 " " " " " for experiments 361 Consulting Engineer, conclusions and recommendations of 85 " " reference to 2 " " report of 27 Consumption of water, from Indian Creek 94 " " " in American cities 95 " " " in Pittsburgh 73, 94 " " " study of 113 see also Water, amount required. Contagion of typhoid fever 13 Contagious diseases, see Typhoid fever Contamination, indication of faecal, in city water 329, 348 Contents, table of. v. Continental Filter Company, invitation sent to Ill Contingencies, estimate for, in cost of filters 65 Copeland, Wm. R., reference to.. 2, 16, 21, 38, 110, 116 " " report of 331 Cornell Dam, reference to 81, 97 Corrosion, see Boilers, experimental. Cost, comparative, of sand and mechanical filtration 4 " comparison between gravity supply and filtration 82 " of construction of filters, itemized 65 " of experiments 361 " of gravity supply from Indian Creek 82 " of installing meter system 78 " of maintenance of filters 66 " of sand filtration plant recommended for Pittsburgh 6 see Indian Creek and Laurel Hill Creek, also Jewell, Sand, Warren, and Worms Tile Filters, cost of. Coster, Wm., of Coster & Riddle, reference to.. 109 Coster & Riddle, analyses of samples from laboratory of 244 " " laboratory of. . 109 Counting bacteria, see Bacteria, method of examination for. Covered filters, necessity for, in Pittsburgh 44 INDEX. 369 PAGE. Covington, Ky., visit to 2 Cracks in concrete, see Sand filters. Creek, see Indian Creek, also Laurel Hill Creek. Crenothrix, found in samples 350 Cribs, filter, efficiency of 237 " reference to 70 see also Etna, Hulton, Millvale, Montrose, Sewickley, Sharpsburg, and Wildwood. Crustacese, found in samples 352 Culture, Koch's plate method 334 Cumberland Manufacturing Company, agreement with Ill see also New York Filter Manufacturing Company, also Mechanical filters, and Warren Filter. Cyanophycese, list of, found in samples 352 Dairies, analyses of well and spring waters from 319 Dam, see Sand filters, storage reservoir. " Storage reservoir for river water. " also, Indian Creek, Laurel Hill Creek, and Squaw Run. Damages, see Indian Creek. Date of, commencing and closing experiments 109 " " first starting filters Ill, 112, 119 " " visits, see Visits. Davison, Wilkins & Davison, reference to 113 Dayton, use of meters in 77 Deaths from, contagious diseases, see Typhoid fever. " " typhoid Fever 11 Depreciation charges, for gravity supply 83, 104 " " for filters 66 " " for pumping machinery, 66, 83 see Charges, also Sinking fund. Depth of sand in filters, see Jewell, Sand, and Warren Filters. Des Moines, use of meters in 77 Diagrams, list of ix. Diatomacese, list of, found in samples 350, 352 Dinobryon, found in samples 350, 352 Director of Public Works, reference to 3, 109, 112 " " " report to, on Driven Well Supply 306 Discussion of, results of chemical analyses 232 Dishes, see Petri dishes. Dissolved oxygen, in effluents from sand filters 123 " " method of determining 232 Dissolved solids, see Solids, see also Suspended matter. Distribution system for auxiliary supply . 71 " of typhoid fever in Pittsburgh 22 Domestic, or Household filters, reference to 71 see also Berkefeld Filter. ' ' use of water 74 Donegal, on Indian Creek water-shed, population of. 90 Drainage area, see Allegheny and Monogahela Rivers, see also Indian and Laurel Hill Creeks. 370 INDEX. ~ . , . . PAGE. Drinking water in mills 23 see also Auxiliary supply. Driven well, analyses of samples from 316 " " cost of drilling 361 " " report upon supply from 360 Durability of sand and mechanical filters 5 Dust, atmospheric, as a source of typhoid fever 12 Duties of Commission 1 Effective size of sand, used in Jewell Filter 183 " " " " " Sand Filters 121 " " " Warren Filter 517 Efficiency, bacterial, of sand filters, after scraping 124 " " " effect of cold weather on 44 of filtration, see Jewell, Sand, Warren, and Worms Tile Filters. of sand and mechanical filtration 4 60 Effluents, see Cribs, see also Jewell, Mechanical, Sand, Warren, and Worms Tile Filters " of sand filters used in laboratory 115 Elsner's gelatine 327 Engineer, City, reference to 112 " Consulting, reference to 2 " Resident, reference to ; 2, 7, 38 Engineering, estimate for, in cost of filters 65 Engineers employed by Commission 2 " United States, reference to 19 English filters, see European and Sand filters, see also Berlin, Hamburg, and London. Epidemics of typhoid fever, study of 113 " " " traced to milk supply 14 Estimates. ofBerkefeld Filter Company 112 " of filters for Pittsburgh, 65 see also Costs. Etna, analyses of samples from 299 " crib, analyses of samples from 301 " " description of 299 " tap water, analyses of samples of 304 European filters, reference to covered 44 " " visited 2, 3 see Sand filters, see also Berlin, Hamburg, and London. Evaporation, residue on, method of determining 229 Exhibits, list of, reports to accompany Commission's Report 7 Expenditures, list of 361 Experimental boilers, see Boilers, experimental. " filter plant, description of 114 " filters, results secured with 38 Experiments upon filtration, data to be received by 37 " " " results secured by 38 Experts, list of, employed by Commission 2 Fall River, use of meters in 77 Fayette County, Pa., rainfall in 92 INDEX. 371 PAGE. Fayette County, Pa., reference to 90, 112 see Gravity Supply, see also Indian Creek. Fermentation germs 328 " of sugar 327 Ferric oxide, Ferrous oxide, see Iron oxide Filling from below, see Sand filters. Filter building, description of 115 Filter companies, invitations sent to 110 " " list of Ill Filter plant experimental, description of, see Experimental filter plant. Filtered solids, method of determining 229 Filtering materials, see Jewell, Mechanical, Sand, Warren, and Worms Tile Filters Filters, covered, necessity for 44 " results secured with experimental 38 see Berkefeld, European, Home, Household, Jewell, Mechanical, Sand, Warren, and Worms Tile Filters, see also Cumberland Manufacturing Company, Morrison-Jewell Filtration Company and New York Filter Manufacturing Company. Filtration, annual charges for, see Annual charges, comparison of mech anical and sand 65 cost of 4, 65 cost of, compared with cost of gravity supply 82 effect of. 3 " experiments upon 37 methods of, investigated 28 " nature of 36 Filtration Commission, see Commission. Filtration cribs or galleries, reference to 70 Filtration plant, advisability of establishing 4 " " inspection of 2, 3 Financial statement 361 Fischer, Director, reference to 112 " Tile System, see Worms Tile Filter. Fixture rates, changing to meter rates 77 Flat-lands, survey of 112 Flies as a source of typhoid fever 12 Flinn, Hon. Wm., reference to 3, 112 Fogg, C. E., of Jamison & Fogg, reference to 113 Food, infected uncooked, as a source of typhoid fever 12 Fortune, W. W., reference to 112 Frankstown Avenue, analysis of tap water from 319 Free ammonia, see Ammonia. Freezing of surface of sand filters 120 Fruits, as a source of typhoid fever 12 Fuller, G. W., reference to methods of bacterial examinations 334, 339 " " " report on Louisville experiments 50,54,58, 70 Fungi, list of, found in samples 352 Gagings, see Indian Creek. Galleries, filtration, use of 70 see also Cribs. Garfield Tank, bacterial examinations of samples from 33 372 INDEX. PAGE. Gas, natural, sale of, by meter system 74 Gate chamber, analysis of samples from 246 " " micro-organisms found in samples from 349 " " special samples from 249 " " species of bacteria found in samples from 346 Gelatine, Comte Fils 334 " growth for different days on 338 " liquefaction of 338 " nutrient, method of sterilizing 335 " used in making media 334 General Information, Committee on 1 " remarks, in Resident Engineer's Report 116 German filters, reference to periods between scrapings 47 Glunt spring, analyses of water from 320 Gravity supply 80 " " annual charges for 84 " " comparison between, and filtration . 82 " " conclusions upon 105 " " cost of 82 " " study, cost of. 361 " " reference to 29, 113 " " report upon, by Consulting Engineer 80' " " " "by Emil Kuichling, C. E * 87 see also Indian Creek and Laurel Hill Creek. Greensburg, Pa., rainfall at 92 Greiss' method of determining nitrites, reference to 227 Gutters, vertical iron, see Warren Filter. Hamburg, Germany, visit to 3 Hardness, method of determining 230 " of effluents, comparison of mechanical and sand filtration 62 " of samples collected .*. 237 " permanent, compared to temporary 62 Hazen, Allen, C. E., reference to 2, 8 " " " report of 25 Hazen and White method 327 Head, see Loss of head. Head on filters, see Sand filters. Health, Bureau of, see Bureau of Health. " character of present water supply in its relation to public 8 Healthfulness of Allegheny River water 27 Height of water in filters, see Jewell, Sand, and Warren Filters. Herron Hill Laboratory, reference to 190 " " Reservoir, bacterial examination of samples from 330 " " " micro-organisms found in samples from 357 Herr's Island, reference to 278 Highland Reservoir, also Highland Park Reservoir. " " bacterial examination of samples from 330 " " micro-organisms found in samples from 356 " " reference to end of Indian Creek conduit 89 Hoboken, use of meters in 77 Holland, Dr. W. J., reference to 3, 114, 327 INDEX. 373 PAGE. Holliday, Geo. L., reference to 1 Home filters. Household filters, reference to 71 see also Berkefeld Filter. Howe spring, analyses of samples from 316 Hudson River, reference to 28 Hulton, analyses of samples from 285 " crib, description of. 285 " " analyses of samples from 287 see also Verona. Ice on filters, see Sand filters. Ice supply, reference to 3 " " as a source of typhoid fever 13 Ignition, see Loss on ignition Incrusting constituents 63 see also Boilers, experimental. Indian Creek:- Analyses of samples from 321 As a gravity source of supply 80 Charges, annual 83, 104 Coal land, difficulties with 82, 101 Comparison of cost of supply from, with filtration 82 Conclusions upon 105 Conduit, blow-offs on 101 !l capacity of 95, 99 " coal workings under 101 " coefficient and slope of 100 " cost of 102 " length of 81 " reservoirs, intermediate 101 " size of ~ 100 " route of 99 " spillways and structures on 101 " subsidence 101 " valves and waste weirs on 101 Cost of work 82, 102 Dam, cost of 81, 96, 102 " elevation of 96 " increase of, to store Laurel Hill Creek 93 " masonry in 97 Depreciation charges 83, 104 Description of source of supply 89 Estimates for and cost of engineering 102 Gagings of. 91 Interest charges 104, 105 Maintenance, cost of 103 Mill privileges upon 97 Operations, cost of 103 Pipe line, see Conduit Pollution, prevention of 97 Quality of water 81 Quantity of water available .' 91 374 INDEX, Indian Creek,-Con.:- page. Records of rainfall 91, 92 Report upon, by Emil Kuichling, C. E 97 Reservoir, capacity of 81 " cost of 102 " description of 89, 96 Resler'sRun 89, 90 Roads rebuilt 97 Sinking fund charges 83, 103 Steel pipe, see Conduit. Structures, life of 104 Tunnel, capacity and size of 98 " cost of 102 route of 98 " shafts on and time required for building 99 " slope of 99 " White Run, at end of 98 Water-shed, description of 90 " drainage area of 89 population and towns upon 90 " rainfall upon 91 Western Water Company records 91 see also Gravity supply. Indian Head on Indian Creek water-shed 90 Indicator, rate of flow, see Sand and Worms Tile Filters. Infected uncooked food, as a source of typhoid fever 12 Infection, secondary 3, 13 Infectious diseases, see Typhoid fever. Information, General, Committee on 1 Inspection of, filtration plants 2, 3 " " rivers and water-sheds 3 Installation, cost of, for experiments 361 Intake, estimated cost of 65 see also Allegheny and Monongahela Rivers, also Etna, Hulton, Millvale, Montrose, Sewickley, and Wildwood. Interest charges, on cost of filters ' 66 " " on cost of gravity supply 83 Intestinal organisms 327 Investigations, pollution, reference to 3, 114 " scope of 1 Iron, in samples 237 in sand, see Chemical analyses of. " method of determining 231 " oxide 159, 202 Jackson, D. D., reference to 349 Jamison & Fogg, reference to 113 Jewell Filter :- Agitator 182 Alkalinity of effluent 185 Alumina, see Coagulant. Area of sand surface '. 180 INDEX. 375 Jewell Filter,-Con.;- page. Bacteria, in effluent 184, 194 at times of washing 188 " in raw water 184, 194 " settled water 194 Bacterial efficiency of, after cleansing 191 " trailing 190 " washing 187 " without coagulant 192 Butterfly valve 180 Cement around screens 181 Chemical analyses of effiuent 262 Cleansing 181, 183, 191 Coagulant, composition of 159 effect of different quantities of. 191 method of application of 180 " used 184 variation in application of. 183 Conduits, area of collecting 181 Cost of experiments 361 Controller, see Regulator. Daily results 193 Description 180 Diagram, see Plan, see Elevation. Effluent, analyses of. 262 " bacteria in 184, 194 Elevation 182 Experiments, cost of. 361 Exit area 181 Float 180 Head, loss of. 189 Hours in operation 193 Meters 181 Micro-organisms found in effluent 355 Monthly results, table of 193 Operations 182 Orifice plate in regulator 181 Plan 182 Rakes 181, 182 Rate of filtration, variation in 183 Records, monthly 192 Regulator for inlet 180 " in effluent pipe 181 Results, tabulation of. 193 Sand, analyses of, 183 " area and depth of. 180 " removed and restored 183 Settled wrater, samples of 264 Settling basin 180 Screens, area of. 181 Soda ash, used to cleanse 191 Solution, see Coagulant. 376 INDEX. Jewell Filter,-Con.:- page. Special experiments, using different quantities of coagulant 191 Sulphate of alumina, see Coagulant. Summary of monthly results : 40 Surface area 180 Time in operation 191 Times of washing 193 Trailing, effects of 189 Turbidity, observations of 193 Washing, bacterial efficiency after 187 " list of. 193 Wash water 181 see New York Filter Manufacturing Company, Morrison-Jewell Filtration Company, see also Mechanical Filters. Johnstown, Pa., rainfall at 92 Jones Mills, on Indian Creek water-shed 90 Kansas City, use of meters in 77 Kiskiminetis River as a gravity source . 80 ■ Kittanning, analyses of samples from 321 Knabe's well, analyses of samples from f... 320 Knowles, Morris, C. E., reference to 2, 7, 38 " " " report of 107 Koch's plate culture method, reference to 334 Kuichling, Emil, C. E., reference to 6, 8, 29 " " " report on Indian Creek gravity supply by 87 Laboratory, biological, reference to 110, 114 " chemical, " 109 ' ' cost of equipping 361 " Herron Hill, reference to 109 " of Bureau of Health 110,327, 333 Land, estimated cost of, for filter sites 65 Larimer Ave., analysis of tap water from 319 " " " spring " 319 Laurel Hill Creek:- Analyses of samples from 323 Annual charges 105 As a gravity supply 80 Cost of work 82, 93, 102 Dam, location of. 93 Description of work required 93 Drainage area and capacity of 93 Quantity of water 81 Reference to 89 Tunnel from 93 Laurel Hill Ridge, reference to .... 89 Lawrence, Mass., filter at, reference to loss of head 47 " reference to open filters at 44 typhoid fever in 20 " use of meters in 77 " visit to 2 Leffmann, Henry, reference to 227 Lettuce as a source of typhoid fever 12 INDEX. 377 PAGE. Ligonier, reference to 80 Lime, see Alkalinity, Calcium carbonate and Hardness. Lock No. 4, Monongahela River, rainfall at 92 Logwood, used in determining alumina 231 London, England, filters at, reference to loss of head 47 " " visit to 3 Loomis-Manning Filter Company, invitation sent to Ill Loss of head, reference to limit of 47 see also Jewell, Sand, Warren, and Worms Tile Filters. Loss on ignition, method of determining 229 " " in samples. 237 Louisville, Ky., report upon experiments at, reference to 50, 54, 58, 70 " " visit to 2 Lowell, Mass., typhoid fever in 20 " " use of meters in 77 Lycippus, Pa., rainfall at 92 Madison, use of meters in 77 Maintenance, cost of experiments 361 " estimated cost of; filters 66 " estimated cost of; gravity supply 103 Manchester, use of meters in 77 Manganous sulphate used in determining dissolved oxygen 232 Manning, Loomis-Manning Filter Company, reference to Ill Manufactories, drinking water in 71 Manufacturing, supply of water, see Auxiliary supply. " use of water 71, 75 Maps, list of ix. Masonry, see Costs of filters, see also, Indian and Laurel Hill Creeks. Massachusetts State Board of Health, reference to reports of 335, 336 McConway, Wm., reference to 1, 2 McConway-Torley Manufacturing Company, analyses of samples from well at.... 317 Mechanical analyses of sand, see Jewell, Sand and Warren Filters. Mechanical Filters:- Absorption of sulphate of alumina 54, 58 Action of sulphate of alumina 56 Alkalinity required, for sulphate of alumina 57 Alumina, see Sulphate of alumina. Bacterial efficiency, after -washing 49 " " compared with sand filters 60 " highest, which can be obtained at Pittsburgh 59 " " influence of sulphate of alumina upon 50 " " " turbidity upon 52 " " monthly averages ; 40 " " quantity of sulphate of alumina required to produce 56 Boiler use of effluent, compared to sand filters 63 Calcium carbonate required for sulphate of alumina 57, 59 Clarification, amount of sulphate of alumina required for 55 Clearness of effluents 61 Coagulants other than sulphate of alumina 76 Coagulant, see Sulphate of alumina. Color of effluents 62 378 INDEX. Mechanical Filters,- Con.:- page. Comparison with sand filters 60, 63, 68 Composition of water before and after filtration 43 Cost of sulphate of alumina 67 " " construction 64 " " effected by patents 65 " " maintenance 66 Depreciation 67 Efficiency, see Bacterial efficiency. Effluents compared, with those of sand filters 60 " waste of, after washing 49 Estimated cost of 65, 66 Hardness of effluent 62 Installation invited 110 Life of 67 Lime, see Calcium carbonate. Maintenance, cost of 66 Muddy waters, see Turbidity. Patents, effect of, upon cost 65 Quantities of water and rates of filtration 40, 41 Results with, classified 48 Sensitiveness to application of sulphate of alumina 61 Soda ash, use of in connection with sulphate of alumina 59 Storage reservoir for raw water, necessity of. 68 Sulphate of alumina, absorption of. 54, 58 " " " action of. 56 " il " alkalinity required 57 " " " amounts used and required 40, 43, 55, 56 " " " average results with various quantities 54 " " " bacterial efficiency, influence on 50 " " " calcium carbonate required 57, 59 " " " cost of. 67 " " " safe amount to use 56 Summary of results by months 40 Turbidity, absorption of sulphate of alumina caused by 54, 58 " influence of, upon bacterial efficiency 52 Wash water used and waste 40, 41 Washing, bacterial efficiency after 49 Waste 41, 49 Water quantities, monthly averages 41 see also Jewell and Warren Filters. Mechanical filter companies, invitations sent to Ill see also Filter companies, Cumberland Manufactur- ing Company, Morrison-Jewell Filtration Com- pany, and New York Filter Manufacturing Company. Media, reaction of. 339 Members of Commission, list of 8 Merrimac River compared to the Allegheny River 20, 28 Meters, trouble wfith air in 118 " use of, at Pittsburgh, recommended 73 " " " " report of Commission on 7 INDEX. 379 PAGE. Meter rates, equitable basis for 77 Meter system, adoption of, for Pittsburgh 73 " " cities which have adopted 76 " " cost of installing 78 " " regulations for 76 Methods of bacterial examination 334 " " chemical analyses 225 " 11 filtration investigated 28 Metropolitan Water Boaid, reference to chief engineer of 92 Micro-organisms, cost of work upon 361 " defined 333 " report upon 349 Microscopical investigations 331, 349 Milk supply, as a source of typhoid fever 14 " " reference to 3 Mill Run, analyses of samples from..., 322 " " on Indian Creek water-shed 90 Mill supply of drinking water, as a source of typhoid fever 23 " " " water, see Auxiliary supply, also Manufacturing use. Millvale, analyses of samples from 305 ' ' crib, description of. 306 " tap water, analyses of samples of 309 Milwaukee, use of meters in 77 Mine waste, effect of, on sand filters 45 Mineral analysis of Allegheny River 243 " " " Monongahela River 274 Miscellaneous city samples, analyses of 318 Miscellaneous studies 113 " " cost of 361 Miscellaneous suburban samples, analyses of 320 Monongahela River, analyses of samples from 270, 312 " " Beck's Run, analyses of samples from 319 " " character of. 232 " " character of water supply drawn from 31 " " composition of, water 33 11 " intake of Monongahela Water Company 270 " " list of cities and towns upon 32 " " Lock No. 4, rainfall at 92 " " mineral analysis of. 274 " " sanitary condition of water drawn from 31 " " Turtle Creek, analyses of samples from 319 Monongahela Water Company, intake of 270 " " " reference to 16, 32, 79 Monthly results, summary of 39 see also Jewell, Sand, Warren, and Worms Tile Filters. Montrose, analyses of samples from 278 " crib, description of. 278 " effluent from crib, analyses of 280 see also Allegheny City water works. 380 INDEX. PAGE. Morrison-Jewell Filtration Company, reference to Ill see also Jewell and Mechanical Filters, also New York Filter Manufacturing Com- pany. Mortality, see Deaths. Mount Vernon, filter at, reference to loss of head of 47 Mud, effect of, on sand filters 45 Muddiness of Allegheny River, how effected by storage 68 " " " " reference to 34 Nashville, Tenn., use of meters in 77 Natural gas, see Gas. Natural sand filtration, through cribs or galleries 70 see also Sand filtration and Sand filters. Nature of filtration 36 Negley Run spring, analyses of samples from 319 Negotiations with filter companies .Ill Nessler's, reagent and tubes 226 New York City, reference to Cornell Dam 81, 97 " " typhoid fever, death rate in 11 " use of meters in 77 New York Filter Manufacturing Company, invitations sent to Ill " " " " reference to purchase of Warren and Jewell Filters 65, 111 Nitrates, nitrogen as, method of determining 228 " " " in samples 237 Nitrites, " " method of determining 227 " " " in samples 237 Nitrogen, see Ammonia, "Nitrates, Nitrites. Observations, list of 116 Observers, list of. 117 Odors due to micro-organisms 350 " in samples of water 225 Ohio River, at Sewickley, analyses of samples from 310 " reference to, see Louisville, Ky. Oil City, distance from, and time of flow from, to Pittsburgh 19 Oil Well Supply Company, reference to 115, 226 Open filters, effect of winter on 44, 60 Operation, cost of experiments 361 see Jewell, Sand, Warren, and Worms Tile Filters. Organic matter, in river water 233 see Ammonia, Nitrates, and Nitrites, see also Micro-organisms. Organisms, see Micro-organisms. Organization of Commission 1 " of force 109 Orifice indicators, used with sand filters 118 Oscillaria, found in samples 344, 352 Other Sources of Supply, Committee on 2 " " report of Commission on, reference-to 29 see Gravity sources. Over-flow, see Sand filters. INDEX. 381 PAGE. Oxidation, reference to 233 Oxide of iron, see Iron oxide. Oxygen, dissolved, in effluents from sand filter 123 see also Dissolved oxygen. Oysters, as a source of typhoid fever 12 Parietti's solution 327 Paris, visit to 3 Patents, on mechanical filters 5 " " " " effect of, on cost 65 Pawtucket, use of meters in 77 Pennsylvania, Department of Internal Affairs, records of 91 Perchloride of iron 202 Periods, between scrapings 47 Permanganate, see Caustic permanganate. Permanency of filters, see Depreciation. see also Life of filters. Peoria, use of meters in 77 Petri dishes 335 see also Plates. Petroleum, effect of, on sand filters 45 Phenolphthalein, used as an indicator 334,340 Pike Run, analyses of samples from 323 Pipe, Pipe lines, see Conduit, also Indian Creek, conduit. Pitcairn, Robt., reference to 1 Pittsburgh, city tap water, analyses of 244 " Meter Company, reference to 158 Plants, list of, found in samples 352 Plates, artificial sandstone, see Worms Tile Filter. " list of ix. " number of days allowed to develop 238, 239 " used in bacterial experiments 335 " see also Petri dishes. Plating, method of 335 Police census of Pittsburgh, reference to 22 Pollution investigations of rivers and water-sheds 3, 114 Population of Pittsburgh, 27 " " now supplied by city water works 174 " " study of increase of 113 " " tabulation of, 1883-1900 73, 74 " " within 10 miles of City Hall 74 Potassium chromate, used in determining chlorine 228 " sulphocyanate used in determining iron, 231 Poughkeepsie, filters at, reference to loss of head of.... 47 ' ' reference to open filters 44 Precipitate formed from solution of sulphate of alumina 56 Precipitation at Pittsburgh, 35 " near Indian Creek water-shed 92 Preliminary examination of samples 225 Present water supply, character of 3, 30 Pressure regulator H5, 158 382 INDEX. PAGE. Prodigiosus, Bacillus, application of 345 Proteus group 328 Protozoa, found in samples 350, 352 Providence, use of meters in 77 Public health, character of present water supply in relation to 3 Public Safety Department, laboratory of Bureau of Health 110, 327, 333 " " " tap in building of, analyses of samples from 312 Public water supply, as a source of typhoid fever 14 " " " for institutions and meter system 76 " " " use of water from 75 Public Works, Director of, reference to 3, 109, 111 Pumps, see Jewell and Warren Filters. Pumping machinery, depreciation of 66, 83 " " pump house, estimated cost of 65 Pumping station, see Auxiliary supply. " also Filter estimates. Purification, self, of streams 17 Quality of water, see Bacteria, see Water. " also Indian Creek and Laurel Hill Creek. " " Jewell, Sand, Warren, and Worms Tile Filters. Quantity of water required, see Water, quantity required. Quantity passed, see Jewell, Sand, Warren, and Worms Tile Filters. Quincy, use of meters in 77 Quiescence, as a factor in self-purification of streams 17 Rainfall at Pittsburgh 35 " various places near Indian Creek water-shed 92 see also Precipitation. Rains, effect of, on rivers ' 232 Rakes, see Jewell and Warren Filters. Rapidity of streams as a factor in self-purification 18 Rates, equitable basis of, for meter system 77 " of filtration, see Jewell, Sand, Warren, and Worms Tile Filters. " of flow, see Allegheny River. " also Jewell, Sand, Warren, and Worms Tile Filters. Raw water, bacteria in, monthly averages 39 Reaction of media 339 Recommendations of Commission 7 " " Consulting Engineer 85 Reducing pressure valve 115, 158 Red Wing, Minn., sand from 180 Regulator, for thermostat 337 " pressure, on main water line 115, 158 see Jewell and Warren Filters. Renewals, charges for, see Costs, Depreciation, Estimates. Report of Commission 1 Reports, list of. • 7 Representatives of filter companies Hl Reservoir, estimated cost of 65 " species of bacteria found in 346 " storage, for raw water 68 see also Gravity Supply, Indian Creek and Squaw Run. INPEX. 383 PAGE. Resident Engineer, reference to 2, 7, 38 Resident Engineer's Report 107 " " " reference to 7, 38 Residue on evaporation, method of determining 229 " " " in samples 237 Resler's Run, analyses of samples from 323 " " reference to 89, 190 Resolution creating Commission iii Restriction in waste of water 73 Results with experimental filters . 38 Riddle, Dr. Walther, reference to 2, 38, 109, 116 " " report of 223 River sands, analyses of 121 River water, bacteria in and turbidity of, monthly averages 38 " " used in mills 23 see also Allegheny River, Monongahela River, also Auxiliary supply. Rivers, see Allegheny, Monongahela and Youghiogheny, also Indian Creek. River pollution, reference to •. 3, 17, 114 Rivers Pollution Commission, reference to 17 Safety, Department of Public, laboratory of Bureau of Health 110, 327, 333 Salaries, amount of 361 Salt Lick Township on Indian Creek w7ater-shed, population of 90 Samples, chemical analyses of. 237 " how collected 225 Samples of Pittsburgh city water, bacteriological investigations of 325 Sand, see Jewell, Sand, and Warren Filters. Sand, depth of, removed by scraping 47 Sand Filters:- Advisability of establishing '. 4 Analyses of samples from 246 Analyses of sand 121, 122 Area of experimental 118 Asbestos, use of, with 70 Ammonia in sand 122 Auxiliary supply, saving in cost of, by establishing : 72 Bacteria, in effluents 39, 127 " species of 345 " in sand 122 in underdrains, growth of 60 " large numbers in effluent 120 Bacterial efficiency 39, 127 " " after scraping 123 " " compared with mechanical filters 60 Batter of walls 118 Boilers, use of effluents from, in 63 Calcium carbonate in sand 62, 122 Capacity of settling basin 117 Chemical analyses of samples 246 Clearness of effluents . 61 Color of effluents 62 Comparison with' mechanical filters 60, 63, 67 384 INDEX. Sand Filters,-Con.:- page. Composition of river water before and after passing 39 Construction, cost of 64 Construction of experimental, decided upon 110 Cost of construction 64 Cost of experimental 361 " maintenance 66 Covering, necessity of 44 Cracks in filter walls 120 Daily results 127 Dates of operation 119 Depth of sand removed by scraping 47 Description 117 Dissolved oxygen 123 Effect of. 3 " mud, petroleum and mine waste upon 45 " winter on 60 Effective size of sand 122 Efficiency, see Bacterial efficiency. Effluent pipes 118 Effluents, analyses of. 253 " compared with those from mechanical filters 60 Elevation 118 Estimate of cost 65, 66 Experiments with, cost of 361 Freezing of surface, effect of 120 Frequency of scraping 47 Growth of bacteria in underdrains 60 Hardness of effluents 62 Indicators, reference to 118 Leaks through filter walls 120 Leveling on surface 121 Lime in sand, see Calcium carbonate. Loss of head 47, 120, 127 Location of experimental 114 Maintenance, estimated cost of 66 " of experimental, cost of 361 Mechanical analyses of sand 121 Meters used with experimental 118 Methods used with experimental 120 Micro-organisms found in effluents 349, 354, 355 Monthly results 126 Net yield from, monthly averages 39 Operations 119 Organic matter in sand 122 Orifice indicators 118 Overflows 118 Oxygen, dissolved 123 Periods of operation 119 " " between scrapings 47 Plan 118 INDEX. 385 Sand Filters,-Con.:- page. Quantities between scrapings 47 " filtered 127 Rates of filtration 39, 119, 123, 127 Reference to experiments with HO Repairs to experimental 120 Results, tabulation of 126 " with, classified 44 River sands, analyses of 121 Samples from, analyses of. 246 Sand, analyses of 121, 122 " area of. H® " bacteria in 122 " elevations of H® " freezing of 120 " removed by scraping 118, 127 size of 121, 122 '' tamped 121 Scraping, bacterial efficiency after 123 " frequency of, and periods between 47 " list of 127 " rate of filtration after 123 Section H® Sedimentation, necessity for preliminary 44 Settling basin, description of 117 Settled water, analyses of. 250 Species of bacteria found in effluents from 345 Storage reservoir for raw water, necessity for 68 Summary of results with, by months 39 Tabulation of results 126 Tamping of sand 121 Time in operation 127 Turbidity, records of 127 Underdrains, description of 118 " growth of bacteria in .'. 60 Walls, cracks in 120 Sandstone tiles, see Worms Tile Filters. Sand washing, see Jewell and Warren Filters. San Francisco, use of meters in 77 Sanitary condition of present water supply 3, 30 Sanitary studies, cost of 361 see also Pollution investigations. Scale, see Boilers, experimental. Schenley Park tap, bacterial examination of samples from 330 Scope of investigations ^1 Scraping, see Sand filters. Screens, see Jewell and Warren Filters. Secondary infection 3 Secretary of Commission 1 Sedgwick, Prof. W. T., reference to 7, 27 " " " report of. 9 386 INDEX. PAG E. Sedgwick, Prof. W. T., studies made for 113 Sedgwick-Rafter method, reference to 349 Sediment in samples of water 225 Sedimentation, necessity of preliminary, for sand filters 44 Sedimentation basins, can be built over into filters 69 " " estimated cost of ~ 65 Seger's well, analyses of water from 320 Self-purification of streams 17 Sensitiveness of mechanical filters to application of sulphate of alumina 61 Serial numbers of samples 237 Services, how to be metered 76 Service pipes to be overhauled 78 Settled water, sand filters, analyses of samples from 250 " " bacteria in, and composition of, monthly averages 39 Settling, necessity of, with sand filtration 44 Settling basin, analyses of samples from 250 " estimated cost of 65 see also Sedimentation basins, also Jewell, Mechanical, Sand, War- ren, and Worms Tile Filters. Sewage pollution, see Pollution investigations. Sewickley, analyses of samples from 310, 311 " crib, description of 310 Shafts, see Indian Creek, tunnel, also Tunnel shafts. Sharpsburg crib, analyses of samples from 298 Shepherd, A. B., reference to report of 109 " " report of, on Driven Well Supply 360 Shetland Ave., analyses of tap water from 319 Silver nitrate, used in determining chlorine 228 Simplicity of operation of filters 5 Sinking fund charges, on cost of filtration 66 " " on cost of gravity supply 83, 104 Sinks, coal, see Indian Creek, conduit. Size of sand, see Effective size; see also Sand filters. Sligo Mills, analyses of samples from well at 318 Slow sand filters, see Sand filters. Smith, Frank B., reference to 116 " Theobald, reference to 327 Soap solution, reference to 230 Soda ash, use of, in connection with sulphate of alumina 59 Sodium hydrate, used in determining dissolved oxygen 232 " " " " nitrates 228 Sodium thiosulphate, used in determining dissolved oxygen 232 Solids, in samples 237 " method of determining 229 Somerset, Pa., rainfall at 92 Sources of samples 237 Sources of Supply, Other, Committee on 2 " " " reference to 29 " " " report of Commission on 6 Sources of typhoid fever, classification of .' 12 South Side, character of water supplied to 31 INDEX. 387 PAGE. South Side, supply of, with filtered water 79 " typhoid fever upon 16 see also Monongahela River. South Side reservoir, micro-organisms found in samples from 358 " tap, analyses of samples from 275 " tap, bacterial examination of samples from 330 Special samples, from Allegheny River 243 " " gate chamber 249 Species of bacteria 344 " work, cost of 361 Spillways, see Indian Creek, conduit. Spirogyra, found in samples 349, 352 Spree River, reference to 28 Spring waters, analyses of. 319, 320 " as a source of typhoid fever 23 Springfield, on Indian Creek water-shed, population of 89, 96 " " " reference to. 90 " Mass., use of meters in 77 Springs, reference to waters from 3 Squaw Run, survey of 112 see also Sand filters, storage reservoir for raw water; also Storage basin. St. Louis, Wormser Filter Plate Company of, reference to 112 Stearns, F. P., reference to water-shed table of 93 Steel pipe conduits, coefficient of 100 " " roughness of inside surface of 100 see also Indian Creek. Sterilization of media 335 Stigeoclonium, found in samples 349, 352 Still, ammonia 226 Storage reservoir for raw river water, estimated cost of. 65 " " " necessity for 68 Stoyestown, Pa., rainfall at 92 Studies, miscellaneous 112 see also Investigations. Subsidence over coal workings, see Indian Creek. Suburban samples, analyses of miscellaneous 320 Sudbury River, rainfall on water-shed 92 Sulphate of alumnia, absorption of, by muddy waters 54, 58 " " action of and safe amount to use 56 " " estimated cost of 66, 67 see also Coagulant, also Jewell, Mechanical, and Warren Filters. Sulphuric acid, in Monongahela River 233 " "in samples 237 " " method of determining 230 Summary, see Conclusions. Superintendent, to meter services 76 Superintendent of Bureau of Water Supply and Distribution, report by 360 Supply, Other Sources of, Committee on 2 see also Gravity supply, also Water supply. 388 INDEX. PAGE. Surveys, of filter sites, reference to 112 see Indian Creek. Suspended matter, absorption of sulphate of alumina, with different amounts of. 58 " " in samples 237 " " method of determining 229 Syracuse, use of meters in 77 Systems, see Distribution system, also Meter system. " of filtration, see Filters, also Filtration. Tanks, effluent 115 see also Worms Tile Filter. Taps, analyses of samples from, in Pittsburgh 319 bacterial examination of samples from 330 " in Department of Public Safety Building, analyses of water from 312 " species of bacteria found in 346 see also Allegheny, Etna, Millvale, Pittsburgh, Sewickley, Sharpsburg, South Side, Verona, and Wilkinsburg. Taste in waters, see Odors. Taunton, use of meters in 77 Temperature, appliances used to control, in thermostat 337 " at Pittsburgh 36 average of thermostat 336. " development of plates, effected by 338 " effect of, on open filters at Pittsburgh 44 " thermostat, by months 336, 342 " usedin bacterial examinations 336 Temporary hardness, see Alkalinity, also Hardness. Tests for Bacillus coli communis 348 Thames River, reference to 28 Theory of filtration -. 1 36 Thermal death point 347 Thermostat, temperature in 336, 342 " temperature, regulator for 337 Thick waters, reference to 52 Thiocyanate, used in determining iron 231 Thompson's Run, analyses of water from 320 Thompson Street, analyses of tap water from 319 Tiles, see Worms Tile Filter. Toledo, use of meters in 77 Total hardness, see Hardness. " solids, see Solids. " also Residue on evaporation. Towns on water-sheds, see Allegheny and Monongahela Rivers, also Indian Creek. Toy, Wm., reference to 117 Trailing, see Jewell Filter. Tunnel under Allegheny River, estimated cost of. 65 " see Indian Creek, tunnel; also Laurel Hill Creek, tunnel. Turbidity, absorption of sulphate of alumina by 54 " classified 53, 225 " daily observations, see Jewell, Sand, Warren, and Worms Tile Filters. " effect of, on sand filters 45 INDEX. 389 PAGE. Turbidity, effect of, on mechanical filters 52 " how observed 34, 68, 225 " of samples 237 " of mountain streams, of gravity supplies 80 " of river water, monthly averages 39 " of river water, summary of observations 35 " storage, effect of, upon 68 Turtle Creek, analyses of samples from 320 Twenty-first ward, analyses of samples from 318 " " typhoid fever in 113 Typhoid Fever:- Contagion of. 13 Deaths in Pittsburgh from 11 Diagrams showing distribution of 22, 24 Distribution of, in Pittsburgh 22 Epidemic of, traced to milk supply 14 Germs, difficulty of detecting 21 Ice supply, as a source of 14 Infection, secondary 3, 13 Milk supply, as a source of. 14 Monongahela River water, as a source of 15 Report upon sources of 9 Secondary infection 3, 13 South Side, amount of, upon 16 Studies of. 113 Water supply, as a source of 14 Ulothrix, found in samples 349, 352 Underdrains, growth of bacteria in 60 " of sand filters 118 Unfiltered supply of water, see Auxiliary supply. Uniformity coefficient of sand, see Jewell, Sand, and Warren Filters. Uniontown, Pa., rainfall at 92 United States Engineers, reference to 19 " " Weather Bureau, rainfall records from \ 92 Utica, use of meters in 77 Valves, see Indian Creek, valves. " also Reducing pressure valve. Vegetables as a source of typhoid fever 12 Vehicles of typhoid fever 12 Velocity of Allegheny River ' 19 Verona tap, analyses of samples from 289 see also Hulton. Vice-chairman of Commission 1 Visits to experimental filter plant 116 " " other cities 2, 116 Wages, amount of : 316 Warren Filter:- Agitator 158 Air needed to supply weir 158 Alkalinity of effluent 161 Alumina, see Sulphate of alumina. 390 INDEX. Warren Filter,-Con.:- page. Analyses, bacterial 171 " chemical 260 " of sand used 157 Application of coagulant 155 " " " variation in 160 Area of exit openings 157 " " sand 156 Automatic weir 155, 157 Bacteria in effluent 160, 171 " " " after washing 166 " " f£ no coagulant used 170 " " raw water 160, 171 " " settled water . 171 Bacterial efficiency after washing 166 " " with different amounts of coagulant 170 Baffle wralls 155 Brass strainer floor 156 Butterfly valve 155 Calcium carbonate, see Alkalinity. Chemical analyses of effluent 260 Coagulant, application of. 155 " " " variation in 160 " composition of 159 " effect of using different quantities of 169 " pumps and tubs 156 Cost of experiments with 361 Daily results 171 Description 155, 156 Depth of sand 157 Efficiency, see Bacterial efficiency. Effluent, alkalinity of 161 " analyses of samples of 260 " bacteria in, after washing 166 " micro-organisms found in 355 Engine, power from 158 Error in meters 158 Exit area 157 Experiments with, cost of 361 Filtration, variation in rate of 160 Flap valve 155 Float in settling basin 155 " weir 157 Floor, strainer 156 Gutters 157 Hours in operation 171 Leaks from tanks 158 Lift, hydraulic 158 Micro-organisms found in effluent 355 Meters 155 " error in, caused by air... 158 Monthly results, tabulation of ■ 40, 171 INDEX. 391 Warren Filter,-Con.:- page. Operations 159 Orifice ring in weir 157 Power used in washing 158 Pressure valve, reducing 158 Propeller .-. 155 Pump, coagulant 156 Quantities filtered 171 Quartz used 157 Rakes 158 Rate of filtration, variation in 160 Records of operations 159 Regulator, pressure 158 Results by months, tabulated 40, 171 Ring, orifice, in weir 157, 160 Rubber valves 156 Samples, analyses of 260 Sand, analyses of. 157 " area of 156 " depth of 157 Screens, brass 157 Section : 156 Settled water, analyses of samples of 262 Settling basin, description of 155 Special experiments 160, 169 Sulphate of alumina, analyses of 159 " " quantities used 160, 172 Summary of results 40 Surface, area of 156 Tests, special 160 Time in operation 172 Troughs 157 Turbidity of effluents 171 Tympanum 156 Valve, butterfly and flap 155 " reducing pressure 158 " rubber 156 Variations in rate of filtration and the application of coagulant 160 Washing, description of 157 ' ' effect of 166 " list of 172 Weir, automatic 155, 157 Well, central 157 see also Cumberland Manufacturing Company, Mechanical Filters, and New York Filter Manufacturing Company. Wasdin, Dr. Eugene, reference to 120 " " report of. 325 ' ' " table of results secured 330 Washing, Wash water, see Jewell, Mechanical, and Warren Filters. Wash water pumps 115 Washington County, Lock No. 4, rainfall in 92 392 INDEX. PAGE. Waste of water in Pittsburgh 73, 95 " water, see Jewell, Mechanical, and Warren Filters. " weir, see Indian Creek, conduit. Wasting effluents 49 see also Jewell, Mechanical, and Warren Filters. Water Analysis, Committee on 1 " borne diseases 3 see also Typhoid fever. " domestic, use of 47 " manufacturing use of. 71, 75 " public use of ' 75 " sheds, inspection of 3 see also Allegheny and Monongahela Rivers, Gravity sources, Indian and Laurel Hill Creeks. " supply, as a source of typhoid fever 14 " Bureau of, and Distribution, money expended by 361 " " character of present 3 " " gravity, reference to 6, 29, 80 see also Allegheny and Monongahela Rivers, Gravity sources, Indian Creek, and South Side. " to be provided^and restriction of waste 73, 74, 93 Weather Bureau, records of rainfall 92 Weirs, automatic,lsee Warren Filter. " waste, see Indian Creek, conduit. Wells, analyses of samples from 319, 320 " supply of water from 3 see also Driven well, McConway-Torley Manufacturing Company, Sligo Mills. Western University of Pennsylvania, students of, employed 114 " Water Company, communication from 113 " " " property rights on Indian Creek 81 Westmoreland County, Pa., rainfall in 92 " " " reference to, on Indian Creek water-shed 90 West Newton, Pa., rainfall at 92 White Run, reference to, end of Indian Creek tunnel 98 Widal-Pfeiffer, blood test, reference to 327 Wildwood, analyses of samples from 292 " crib, description of. 292 " " analyses of samples from 294 " see also Wilkinsburg. Wilkins & Davison, reference to survey by 113 Wilkinsburg Reservoir, asterionella found in 351 " " micro-organisms found in 358 " tap, analyses of samples from 296 see also Wildwood. Winter, effect upon sand filters ...44, 60, .120 Worcester, use of meters in 77 Worms Tile Filter:- Analyses of samples from 265 Artificial sandstone tiles 203 Bacteria, daily results 207 INDEX. 393 Worms Tile Filter,-Con.:- - page. Bacterial efficiency 205 Breakage of tiles 204 Chloride of iron 202 Clogging of tiles , 205 Coagulant 202 Composition of tiles 203 Cost of experiments with 361 Daily results 207 Description 202 Effluents, analyses of 268 " bacteria in, after washing 205 Elevation 201 Estimated cost -70 Experiments, cost of, with 361 Ferric chloride 202 Hours in operation 212 Indicators 203 Iron ore used 212 " solution 202 Loss of head 204 Monthly results '. 207 Negotiations in'regard to 112 Opalescence of effluents 203 Operations ; 204 " hours in 212 Orifice indicator 203 Place of manufacture •. 203 Plan 204 Quantities filtered, and, of wash water 212 Rate of flow 204 Reference 69 Results, tabulation of. 207 Samples, analyses of. 265 Scrubbers 202 Section 204 Settled water, analyses of 266 Tanks and tiles 203 Turbidity, records of 212 Washing, bacterial efficiency after 205 " list of 212 method of 203 Wash water, amount of .' 204 Worms, Germany, reference to filters used at Ill Wormser Filter Plate Company, reference to Ill Wurtz litmus agar 328 Yield of filters, see Jewell, Mechanical, Sand, Warren, and Worms Tile Filters. Yonkers, use of meters in 77 Youghiogheny River, analyses of samples from 324 '* " as a gravity source of supply 80