STATE OF ILLINOIS 
DWIGHT H. GREEN. Governor 
MINIMUM SANITARY REQUIREMENTS 
FOR 
SWIMMING POOLS AND BATHING 
PLACES 
WITH 
Additional Information and Suggestions 
on Design and Construction 
Adopted July 15, 1935 
Revised May 1, 1938 - Revised May 1, 1945 
DEPARTMENT OF PUBLIC HEALTH 
ROLAND R. CROSS, M. D., Director 
(Printed by authority of the State of Illinois) STATE OF ILLINOIS 
DWIGHT H. GREEN, Governor 
MINIMUM SANITARY REQUIREMENTS 
FOR 
SWIMMING POOLS AND BATHING 
PLACES 
WITH 
Additional Information and Suggested Satisfactory 
Compliance for the Design, Construction, and 
Equipment, Including Items of Safety 
(Adopted July 15, 1935 - Revised May 1, 1938 - Revised May 1, 1945) 
DEPARTMENT OF PUBLIC HEALTH 
ROLAND R. CROSS, M. D„ Director 
Prepared by 
DIVISION OF SANITARY ENGINEERING 
WILLIAM J. DOWNER, Chief Sanitary Engineer FOREWORD 
The successful modern swimming pool involves a multitude 
of problems not always appreciated by the general public. Such 
a pool includes not only engineering and architectural problems 
but also health, recreational, and social problems. A swimming 
pool, to be successful from a public-health, financial, and recrea- 
tional standpoint, requires careful planning in regard to its loca- 
tion, size, layout, construction, equipment, and operation. 
It is the aim of this bulletin to acquaint those involved in 
swimming pool design, construction, and operation with the par- 
ticular details with which this Department is primarily concerned. 
This bulletin not only includes the Department’s minimum sani- 
tary requirements but also sets forth opinions as to good practice 
in meeting those requirements necessary for a successful swimming 
pool. Each pool project has its particular problems, and it is the 
intention in presenting this material that it serve not merely as 
“minimum standards’’ but as a guide in successfully meeting the 
problems of the particular pool project. 
Through investigations, study, and contact with pools through- 
out the State, the Department is in a position to observe many 
types of swimming pool facilities, and thus to act as a clearing 
house for improvements which will result in more successful pool 
installations. Considerable of this bulletin’s material is based on 
such investigations and studies. If those persons contemplating new 
or improved pools will make contact with the Department prior to 
the preparation of the final plans, it is believed that much benefit 
will result. 
It has been the policy of the Department of Public Health 
to revise its swimming pool bulletin from time to time in order 
that latest developments in swimming pool construction, design, 
and operation may be brought to the attention of interested indi- 
viduals in Illinois. Previous bulletins were issued under dates of 
July 15, 1935, and May 1, 1938. 
A satisfactory and successful swimming pool results in bene- 
fits to the owners and patrons and reflects credit on all those 
connected with its design, construction, and operation. It is hoped 
that this bulletin will aid in promoting the installation, and effici- 
ent and economical operation, of swimming pools, and it is to this 
end that this material is offered. AUTHORITY FOR CONTROL OF SWIMMING 
POOLS AND BATHING PLACES 
Authority for control of swimming pools and bathing places 
is vested in the Department of Public Health by the provisions 
of Paragraphs 2 and 3 of Section 55 of the Civil Administrative 
Code as amended in 1931, which states: “The Department of 
Public Health shall have power to have the supervision of the 
interests of the health and lives of the people of the State * * * 
shall have power to examine public swimming pools and bathing 
places and prepare and enforce rules and regulations covering 
their construction and operation and use to the end that they will 
be constructed and maintained in a sanitary manner”; also in ac- 
cordance with “An Act for the control of swimming pools” (Ap- 
proved July 8, 1931, in force October 1, 1931) : 
“Be it enacted by the People of the State of Illinois, repre- 
sented in the General Assembly: 
“1. DEFINITION: Swimming pool as used in this Act shall 
mean an artificial pool of water and auxiliary structures includ- 
ing dressing and locker rooms, toilets, showers and other areas 
and enclosures that are intended for the use of persons using the 
pool but shall not include pools and auxiliary structures and equip- 
ment at private residences intended only for the use of the owner 
and friends. 
“2. SANITARY REQUIREMENTS: The State Department 
of Public Health shall prepare, adopt and have printed minimum 
sanitary requirements for the design, construction, equipment and 
operation of swimming pools. 
“3. PLANS AND SPECIFICATIONS — APPROVAL: No 
swimming pool shall be constructed after October 1, 1931 unless 
and until plans, specifications and any additional information rela- 
tive to such pool as may be requested by the State Department 
of Public Health shall have been submitted to said department and 
after review by said department found to comply with the mini- 
mum sanitary requirements provided in Section 2 of this Act and 
a permit for the construction of the pool issued by said depart- 
ment. 
“4. OPERATION: After October 1, 1931 swimming pools 
shall have equipment and shall be operated so as to comply with 
the minimum sanitary requirements provided in Section 2 of this 
Act. Swimming pools constructed prior to October 1, 1931, which do not fully comply with the minimum sanitary requirements as 
regards design and construction may be continued in use for such 
period as the State Department of Public Health may authorize, 
provided the equipment and operation of such swimming pool 
comply with the minimum sanitary requirements. 
“5. DEPARTMENT OF PUBLIC HEALTH TO DETER- 
MINE SANITARY CONDITION: The owners and/or operators 
of swimming pools shall submit such operation and analytical 
records as may be requested by the State Department of Public 
Health to determine the sanitary condition of the swimming pool. 
“6. PROSECUTIONS: Whenever any duly authorized rep- 
resentative of the State Department of Public Health shall find 
that a swimming pool is being constructed, equipped or operated 
in violation of any of the provisions of this Act, the said depart- 
ment may grant such time as in its opinion may reasonably be 
necessary for changing the construction or providing equipment 
for operating the swimming pool to meet the provisions of this 
Act. If and when the duly authorized representative of the State 
Department of Public Health upon inspection and investigation 
of swimming pool considers that the conditions are such as to war- 
rant prompt closing of such swimming pool until the provisions 
of this Act are complied with, he shall notify the owner and/or 
operator of said swimming pool to prohibit any person from using 
said swimming pool and upon such notification to the sheriff and 
State’s attorney of the county in which such pool is located, it 
shall be the duty of said State’s attorney and sheriff to see that 
the notice of said representative of the State Department of Pub- 
lic Health shall be enforced. If and when the owner or operator 
of said pool, has in the opinion of the State Department of Public 
Health, met the provisions of this Act the said department may 
in writing authorize the use again of said swimming pool. 
“7. FAILURE TO COMPLY WITH ACT—PENALTY: Any 
owner and/or operator of a swimming pool failing to comply with 
any provisions of this Act shall be guilty of maintaining a public 
nusiance and it shall be the duty of the State’s attorney of the 
county in which such swimming pool is located and/or the Attor- 
ney General in the name of the people of the State of Illinois to 
act as provided by law for the abatement of public nuisance.” INTRODUCTION 
The following comments, suggestions, and recommendations 
are offered to: 
(1) Acquaint consulting engineers and architects with items 
given consideration by the State Department of Public Health in 
the review of plans and specifications which are submitted in ac- 
cordance with Section 3 of the Act previously quoted in this bulle- 
tin. 
(2) Serve as a guide in the interpretation of the items con- 
sidered in the sanitary condition of existing swimming pools under 
Sections 4 and 5 of the Act previously quoted in this bulletin. 
(3) Set forth for reference purposes miscellaneous sugges- 
tions on swimming pool features and appurtenances not necessar- 
ily affecting sanitary conditions. 
It is hoped that this bulletin will facilitate the preparation 
and submission of swimming pool plans and specifications as well 
as guide in improving, when necessary, existing installations. 
PROJECTS NOT REQUIRING A PERMIT FOR 
CONSTRUCTION AND OPERATION 
No permit from the State Department of Public Health is re- 
quired for the construction or operation of pools and auxiliary 
structures at private residences intended only for the use of owner 
and friends. 
GENERAL COMMENTS 
(a) Design Data. A summary of the basis of design, includ- 
ing information relative to bathing load, recirculation equipment, 
pool capacity, dressing rooms, disinfection, equipment, etc., should 
be submitted with plans. 
(b) Plans. Detailed construction plans and specifications 
are required and must be approved before a permit for construc- 
tion can be issued. 
(e) Structural Details. The review of plans by the State De- 
partment of Public Health does not cover structural designs. 
(d) New Processes, Methods, and Equipment. The policy of 
the Department of Public Health is to place no obstruction in the 
path of progress in swimming pool design, equipment, and ma- terials. However, any new development must have been tested 
to the satisfaction of the Department before a permit for a pool, 
including the development, can be issued. An experimental in- 
stallation may be permitted, but should the development fail to pro- 
duce results satisfactory to the Department it must be replaced 
with accepted design, equipment, or materials. If the experimental 
installation is made with public funds, any required changes shall 
be made at no expense to the owner. 
(e) Inspections and Opening Approval. Before any new pool, 
or any pool which has been closed for a period longer than one 
year, is opened for public use it shall be inspected by a repre- 
sentative of the State Department of Public Health, and approval 
for opening obtained in writing from the Department. MINIMUM SANITARY REQUIREMENTS 
WATER SUPPLY 
ITEM 1. POOL WATER SUPPLY. The water supply for 
all pools shall be adequate and of satisfactory bacterial, chemical, 
and physical quality. 
Public-health reason—The water from which a pool is supplied 
should have substantially all of the qualities required for a satis- 
factory domestic water supply for essentially the same reasons. 
Satisfactory compliance. This item shall be deemed to have 
been satisfied when: 
(1) The water meets the bacteriological standards of the State 
Department of Public Health for a safe drinking water. 
(2) The source of the supply and any treatment given are ap- 
proved by the State Department of Public Health. 
(3) The water is not unusually corrosive, unless special pro- 
vision is made to protect against corrosion the piping, equipment, 
and fixtures with which it will come in contact. 
(4) The water is of such chemical and physical quality that 
when in the pool the following clarity criterion is met: 
A black disc, 6 inches in diameter on a white field, when 
placed on the bottom of the pool at the deepest point, is clearly 
visible from the sidewalks of the pool at all distances up to 10 
yards, measured from a line drawn across the pool through the disc. 
(5) The water can be delivered at a sufficient rate to enable 
the pool to be operated satisfactorily. 
ITEM 2. SHOWER, LAVATORY, AND DRINKING WATER 
SUPPLY. The water supply for all shower, lavatory, and drink- 
ing water facilities included as adjuncts to the pool shall be of 
satisfactory sanitary quality and adequate in quantity. 
Public-health reason—It is necessary for water supplied to 
showers, lavatories, or drinking facilities to be safe for drinking 
to prevent users from contracting a water-borne disease. 
Satisfactory compliance. This item shall be deemed to have 
been satisfied when: 
(1) The water delivered to any shower, lavatory, drinking 
fountain, or other fixture from which water might be drunk shall 
meet the bacteriological standards of the State Department of 
Public Health for a safe drinking water. 9 
(2) The source of the supply and any treatment given are 
approved by the State Department of Public Health. 
(3) The Avater is delivered in sufficient quantity and Avith 
sufficient pressure to assure the satisfactory functioning of all 
fixtures ser\red by the water supply. 
POOL AND POOL AREA 
ITEM 3. MATERIAL. Pools shall be constructed of con- 
crete, or other approved material, with an impervious finish 
adapted to the bathing demands of the various parts of the pool. 
Public-health reason—If the Avaste discharges of the swimmers 
and other extraneous contamination introduced into the pool can 
not be removed from the pool surfaces with a reasonable amount 
of effort, the pool will probably not be properly maintained, with 
the resultant danger of a biologically unsatisfactory Avater. 
Satisfactory compliance. This item shall be deemed to have 
been satisfied when: 
(1) The pool surface is constructed of a permanently im- 
pervious material Avhich Avill retain a smooth finish with no cracks 
or open joints. 
(2) The bottom surface beloAv a depth of 5 feet is smooth to 
facilitate cleaning and the movement of bottom deposits to the 
main drain. 
(3) The bottom surface aboAre a depth of 5 feet is as smooth 
as practicable while having a nonslip finish. 
(4) Tire Avails and bottom are of a Avhite or other light color. 
(5) The Avails are smooth. 
(6) All junctions between floor and AAralls are rounded. 
(Coved.) 
ITEM 4. SHAPE, DESIGN, SLOPES. The pool shall be de- 
signed and constructed of such shape, contour, etc., that efficient 
and safe control of the pool and bathers can be accomplished. The 
pool bottom shall ha\Te definite slopes to the outlet. Protection of 
the pool area shall be provided so that spectators in street apparel 
can not enter the area used by bathers. 
Satisfactory compliance. The acceptable variations in this 
requirement are so numerous that each design must necessarily 
be judged upon its own merits at the time of submission to the 
State Department of Public Health. 
ITEM 5. WALK AREAS. Walk areas shall be ample in 
size and adequately drained. 
Public-health reason—Dry Avalks are of considerable aid in the 
control of skin diseases, such as “athlete’s foot." The presence 
of Ioav spots in the walk alloAvs water to stand, tending to spread 
skin disorders and permitting accumulations of dirt Avhich the 
bathers track into the pool. 10 
Unless curbs surround the outer edges of the walks, especially 
on outdoor pools, excessive quantities of dirt, litter, and surface 
water may be blown, kicked, or washed onto the walks, making 
the maintenance of a clean pool difficult. Any increase in pool 
turbidity increases the load on the recirculation system and reduces 
the effectiveness of disinfection treatment. 
Since many of the pool patrons will normally use the walks, 
adequate walk area to prevent overcrowding and accidents is 
necessary. 
Satisfactory compliance. This item shall be deemed to have 
been satisfied when: 
(1) The walk is not less than 4 feet wide and is as much 
larger as is necessary to prevent overcrowding and reduce the 
accident hazard. 
(2) The walk is impervious and entirely surrounds the pool. 
(3) A curb is provided on the outside of the,walk area where 
necessary to prevent spectators’ litter from being kicked onto the 
pool walk or to prevent surface water from flowing onto the pool 
walk. 
(4) The walks have a slope of not less than 3 inches in 10 
feet; have a reasonably smooth, nonslip finish; and drain so that, 
after flooding, no standing water may be observed. 
(5) The walks slope away from the pool, or when a curb is 
provided around the pool edge of the walk. Regardless of the 
direction of the walk slope, a pool-edge curb is highly desirable. 
(6) A pool-edge curb is provided for pools having a closed- 
type recirculation system. 
(7) The walk drains are not connected to the recirculation 
system piping. 
ITEM 6. INLETS. Inlets shall be submerged, and be located 
to produce uniform circulation of water throughout the pool with- 
out the existence of dead spots, and to carry pool-bottom deposits 
to the outlets. 
Public-health reason—Stagnant water areas will allow the dis- 
infecting agent residual to disappear and organisms to multiply 
to the detriment of the bacteriological quality of the water. 
Unless the pool-bottom deposits continuously move toward the 
outlet to be removed by the recirculation equipment, they will 
be stirred up by the bathers, thus increasing the turbidity of the 
pool water, which reduces the effectiveness of disinfection, and 
increases the accident hazard. 
Satisfactory compliance. This item shall be deemed to have 
been satisfied when: 
(1) Rectangular pools not exceeding 40 feet by 75 feet have 
inlets across the shallow end which serve a maximum lineal dis- 
tance of 8 feet. 
(2) Rectangular-shaped pools with outlets more than 5 feet 
from the deep-end wall are provided with additional inlets at 
the deep end on a maximum of 12-foot centers. 11 
(3) Inlets are provided on not more than 20-foot centers 
entirely around the perimeter of larger pools. 
(4) All inlets are designed as adjustable orifices, or are in- 
dividually valved. 
(5) All inlets discharge at a depth of 10 to 15 inches below 
the pool overflow level. 
(6) Proof can be furnished to the satisfaction of the State 
Department of Public Health that adequate circulation can be 
obtained by other inlet arrangements. 
ITEM 7. OUTLETS. Outlets shall be ample in size and lo- 
cated at the low points of the pool. The grating area shall be 
sufficient to decrease the possibility of clogging, or of suctions 
dangerous to the safety of the bathers. 
Public-health reason—It is desirable to have the outlets in the 
low points of a pool to aid in obtaining proper circulation of the 
pool water and to facilitate the removal of bottom deposits, the 
necessity for which removal is described in the previous section. 
By having sufficient grating area the possibility of clogging 
with leaves or other material and of bathers being held by suction 
is decreased. 
Satisfactory compliance. This item shall be deemed to have 
been satisfied when: 
(1) Each low point in the pool is adequately served by an 
outlet. 
(2) There are no flat areas near the outlets on which bottom 
deposits may accumulate. 
(3) The area of the grating openings is not less than 10 times 
the outlet pipe area for outdoor pools. 
(4) The area of the grating openings is not less than 5 times the 
outlet pipe area for indoor pools. 
(5) The grating is of such design that it can not be readily 
removed by bathers and will not injure their fingers. 
ITEM 8. LIGHTING. All pools shall be satisfactorily 
lighted. 
Public-health reason-—Satisfactory lighting is essential to the 
maintenance of a clean pool and pool area, a clear water, and the 
safety of the pool patrons. 
Satisfactory compliance. This item shall be deemed to have 
been satisfied when: 
(1) A satisfactory system of artificial lighting is provided 
for an indoor pool and for any outdoor pool to be used at night. 
(2) Lighting fixtures are of such number and design as to 
light all parts of the pool, the water therein, and the entire pool 
area. Lights must be installed in such manner as to create no 
hazard to the bathers, and to prevent light-attracted insects from 
falling into outdoor pools. 12 
(3) The arrangement and design of the lights are such that 
lifeguards may clearly see every part of the pool including walks, 
springboards, towers, floats, and other appurtenances, without be- 
ing blinded by glare. 
ITEM 9. HOSE CONNECTIONS. Sufficient hose connections 
of adequate size and supplied with sufficient water pressure shall 
be provided for cleaning all of the pool area. 
Public-health reason—Probably no single factor will better en- 
courage the thorough cleaning of the pool area than a relatively 
large volume of water under good pressure from conveniently lo- 
cated hose connections. 
A thoroughly cleaned pool walk area is a material benefit in 
reducing the amount of dirt carried into the pool by the bathers, 
and in reducing the danger of spreading skin infections. 
Satisfactory compliance. This item shall be deemed to have 
been satisfied when: 
(1) Hose connections have a minimum size of 1 inch and 
are served by not less than a 1-inch pipe. 
(2) A sufficient number of connections is provided to enable 
all parts of the pool area to be reached with easily manipulated 
hose lengths. 
(3) Water pressure is sufficient to provide effective cleaning. 
ITEM 10. OVERFLOW GUTTERS. Pools shall be entirely 
surrounded by overflow gutters having the necessary pitch to pre- 
vent any accumulations, having ample size to carry off normal 
amounts of water introduced into them, and having easy access 
for cleaning. 
Public-health reason—Flushing off the surface accumulations 
at frequent intervals will allow less material to settle to the bottom 
of the pool. Both scum and sediment may upset the action of the 
disinfecting agent. 
If the bathers are properly controlled the overflows will be 
used for the disposal of nose and throat discharges, thereby re- 
ducing the possibility of introduction into the pool of infectious 
bacteria. 
Overflows should not be completely recessed into the sides of 
pools because recessed overflows are difficult to clean and may be 
overlooked. 
Satisfactory compliance. This item shall be deemed to have 
been satisfied when: 
(1) The overflow gutter extends around the entire perimeter 
of the pool. 
(2) The overflow gutter edge is level within 0.2 inch on pools 
smaller than 40 by 85 feet and 0.3 inch on larger installations. 
(3) The overflow gutter bottom has a pitch of not less than 
3 inches in 10 feet. 
(4) The drains are a maximum of 15 feet on centers. 13 
(5) The runoff capacity is sufficient to carry away all normal 
amounts of water splashed or displaced into them without flood- 
ing of the overflow gutter. 
(6) The overflow gutter has a minimum depth of 4 inches. 
(7) The overflow gutter is of the open, roll-over, or semi- 
recessed type, having a smooth finish, and having an opening suf- 
ficient to permit satisfactory cleaning of the overflow channel. 
(8) Overflow drains that discharge to a sewer or drain have 
a free-fall discharge with an atmospheric break of 2 inches minimum. 
ITEM 11. STEPS AND LADDERS. Steps and ladders shall 
be of an impervious material, and of such design that they can be 
easily cleaned. They shall be so designed and constructed that 
no water is left on them when the pool water level is lowered. 
Public-health reason—Most of the factors in relation to steps 
and ladders affect safety rather than the sanitary conditions of 
the pool. 
Satisfactory compliance. Tt is felt that this requirement is 
sufficiently clear so that no interpretation is necessary, except that 
when step holes are used, provision must be made to provide drain- 
age to prevent dirt accumulation. 
ITEM 12. SUCTION CLEANER. Equipment shall be pro- 
vided to remove sediment, sludge, and other accumulations from 
the bottom of the pool. 
Public-health reason—Jn every pool, bottom deposits accumu- 
late which are too heavy or adhesive to be carried to the main 
drain by the normal recirculation velocities in the pool. These 
bottom deposits, along with those progressing toward the main 
drain, may be stirred up by the bathers with a resultant increase 
in the turbidity of the pool water. Bottom deposits and resultant 
turbidity reduce the effectiveness of disinfection. 
The removal of the bottom deposits by the suction cleaner 
directly reduces the turbidity in the pool. Long-handled brushes 
are comparatively ineffective in moving bottom deposits toward 
the main drain. 
Satisfactory compliance. This item shall be deemed to have 
been satisfied when: 
(1) The pool is provided with a satisfactory suction cleaner 
system of either the built-in or portable type. Built-in types are 
preferable. 
(2) There is sufficient suction and capacity to remove all nor- 
mal accumulations from the pool bottom. 
ITEM 13. SAND BEACHES, GRASS AREA, ETC., IN POOL 
ENCLOSURES. Sand beaches, grass areas, etc., shall not he al- 
lowed inside of the pool enclosure unless properly fenced off to 
prevent access on the part of bathers. If access is allowed to 
such areas, satisfactory facilities shall be provided for the proper 
cleansing of bathers before they again enter the bathing area. 14 
Public-health reason—The volume of sand, grass, and dirt car- 
ried into the pool by bathers indiscriminately passing between the 
pool and beach area with no intermediate cleansing, makes the 
proper operation of the pool extremely difficult. 
Satisfactory compliance. It is believed that this requirement 
is sufficiently clear so that no interpretation is necessary. 
ITEM 14. OUTDOOR POOL LOCATION. Outdoor swim- 
ming pools shall be located where they will not be exposed to ex- 
cessive pollution by dust, smoke, soot, or other undesirable sub- 
stances. 
Public-health reason—By so locating the pool that a minimum 
of extraneous contamination is introduced into the pool and pool 
area, the problem of maintaining them in a satisfactory condition 
is materially reduced, as well as making them more attractive for 
the patrons. 
Satisfactory compliance. This item shall be deemed to have 
been satisfied when: 
(1) The pool is located away from roads or drives which 
are not surfaced or treated to prevent dust. 
(2) The pool is located away from playgrounds, tennis courts, 
etc., which become dusty. 
(3) There are no trees adjacent to the pool. 
(4) The pool is located a sufficient distance from railroads 
or industries which may produce smoke, soot, or other undesirable 
substances, so that the pool area will not be affected adversely. 
ITEM 15. DOUBLE-LEVEL POOLS. Double-level pools 
shall not be permitted. 
Public-health reason—If overflows are provided at the lower 
level, then when the pool is maintained at the upper elevation this 
overflow is submerged. The difficulty in keeping the lower over- 
flow clean because of its location, and the fact that when it is sub- 
merged it may become a source of pollution, are the principal ob- 
jections. 
Satisfactory compliance. It is felt that this requirement is 
sufficiently clear so that no interpretation is necessary. 
RECIRCULATION SYSTEM AND APPURTENANCES 
ITEM 16. RECIRCULATION SYSTEM. The recirculation 
system shall consist of pumping equipment, hair- and lint-catcher, 
and filters, together with all necessary pipe connections to the in- 
lets and outlets of the pool and for backwashing the filters. As 
an integral part of the system, equipment shall be provided for 
disinfecting the water and adding any necessary chemicals and 
make-up water. The entire system and all its component parts 
shall be capable of producing a 6-hour turnover of the entire 
contents of the pool. 15 
Public-health reason—The biological and inorganic contamina- 
tion introduced in a pool’s water will quickly result in its becom- 
ing hazardous to the bathers unless the water in the pool is being 
constantly replaced with water of satisfactory quality. 
Experience has shown that, to date, a modern recirculation 
system of the capacity, and incorporating the units, specified above 
is normally the most economical method of maintaining a pool 
water in satisfactory condition. 
Satisfactory compliance. This item shall be deemed to have 
been satisfied when: 
(1) In addition to providing the 6-hour turnover, the in- 
dividual types of equipment meet the requirements given, as fol- 
lows, for that type of equipment: 
ITEM 16 (a). PUMPING EQUIPMENT. Adequate pumping 
equipment shall be provided. 
Public-health reason—The pump is the heart of the recircula- 
tion system, and, therefore, must be of adequate size. 
Satisfactory compliance. This item shall be deemed to have 
been satisfied when: 
(1) The pump has sufficient capacity to discharge the volume 
of water required for a 6-honr turnover of the pool against the 
maximum head in the recirculation system. 
(2) The pump used for backwashing the filters has sufficient 
capacity to backwash one filter at the rate of at least 15 gallons 
per minute per square foot of filter area. 
(3) The pump develops a good suction when the pipes for 
a suction cleaner are connected to the recirculation system. 
ITEM 16 (b). HAIR- AND LINT-CATCHER. A hair- and 
lint-catcher of acceptable design shall be provided. 
Public-health reason—The strainer, by preventing hair, lint, 
etc., from reaching the filters, results in longer filter runs and 
facilitates filter maintenance. 
Satisfactory compliance. This item shall be deemed to have 
been satisfied when: 
(1) The hair- and lint-cafcher is installed ahead of the filters. 
(2) The strainer is located so as to be easily accessible for 
cleaning. 
(3) The hair- and lint-catcher has the following design fea- 
tures : 
Water passes through the strainer from the outside. 
The strainer is made of noncorrosive metal. 
The width or diameter of the strainer openings is not more 
than one-eighth inch. 
The area of the strainer openings is at least 10 times the area 
of the inlet pipe to the strainer. 
The hair- and lint-catcher is so constructed that it can easily 
and quickly be taken down for cleaning. 16 
A removable cylindrical strainer, with slotted openings, is pro- 
vided unless sufficient cause can be shown for using some other 
type. 
ITEM 16 (c). DISINFECTION EQUIPMENT. Equipment 
shall be provided for the adequate disinfection of all pool water. 
Public-health reason—Only by the adequate disinfection of 
swimming pool water will disease germs introduced into the pool 
be promptly destroyed. 
Satisfactory compliance. This item shall be deemed to have 
been satisfied when: 
(1) Chlorine or chlorine compounds are used as the disin- 
fectant. 
(2) The chlorination equipment has sufficient capacity to feed 
at least 3 parts per million of available chlorine based upon the 
recirculation rate. This capacity shall be increased where abnor- 
mally high chlorine demands are encountered. 
(3) The chlorine is introduced into the recirculation system 
ahead of the filters. 
ITEM 16 (d). COAGULANT EQUIPMENT. The system 
shall include a unit for the addition of a coagulant prior to filtration 
at such point that its use will be effective. 
Public-health reason—A coagulant must be introduced into 
the recirculation system far enough ahead of the filters and effec- 
tively mixed with the water, in order to produce a sparklingly clear 
filter effluent, which is necessary for proper pool sanitation. 
Satisfactory compliance. This item shall be deemed to have 
been satisfied when: 
(1) The coagulant is introduced at a point in the recirculation 
system ahead of the filters and is thoroughly mixed with the water 
so that: 
The floe will be retained on the filters. 
No floe will be formed in the pool. 
(2) The equipment for the addition of the coagulant is con- 
venient to use. 
ITEM 16(e). FILTRATION EQUIPMENT. Filtration equip- 
ment shall be provided on all swimming pools. 
Public-health reason—Adequate filtration will produce a tur- 
bidity-free water which is easier to disinfect, reduces the possibility 
of accidents, and is a primary factor in maintaining the popularity 
of the pool. 
Satisfactory compliance. This item shall be deemed to have 
been satisfied when: 
(1) Sufficient filter area is provided to filter the entire contents 
of the pool in 6 hours at the rate of not more than 3 gallons 
per square foot per minute. 
(2) At least 2 filter units are provided. 17 
(3) When a standard-type underdrain system is used the 
gravel bed is at least 15 inches in depth and varies in gravel size 
from approximately 1% inches at the bottom to approximately ]/8- 
inch at the top. 
(4) The filter sand depth is not less than 24 inches; the effec- 
tive grain size is between 0.45 and 0.55 millimeters; the uniformity 
coefficient does not exceed 1.6, and there is sufficient distance between 
the top of the filter to the point of discharge of the wash water to allow 
for filter media expansion during backwashing at the specified rate 
without loss of filter media. 
(5) Filter media other than sand is employed; special require- 
ments are satisfied. 
(6) Individual rate-controllers and loss-of-head gauges are in- 
stalled on each gravity filter. 
(7) The underdrain system is properly designed to collect 
efficiently the filtered Avater and to distribute properly the backwash 
Avater at a rate of not less than 15 gallons per minute per square foot 
of filter area. 
(8) Each pressure filter is provided with: 
(a) Gauges on the inlet and outlet pipes for deter- 
mining loss-of-head in the filter media. 
(b) Rate-of-floAv indicator. 
(c) Air release Avith a manual control on the highest 
point of the filter, or pipe, on all filters located aboAm pool 
level. 
(d) An easily removed sight glass on the Avaste dis- 
charge line (unless the wash-water discharge is plainly 
visible) for indicating the progress in filter-Avashing or the 
clarity Avhen filtering to Avaste. 
(e) A readily remo\rable head or a large manhole to 
facilitate inspection and repairs. 
(9) The filter piping arrangement is as simple as possible to 
accomplish filtration, backwashing, and filtering-to-Avaste. 
ITEM 16 (f). MAKE-UP WATER FACILITIES. All pools 
shall be equipped with provisions for adding make-up water. 
Public-health reason—Water lost to the overflow (other than in 
closed system) must be replaced in sufficient amounts to skim float- 
ing contamination from the surface of the pool. 
Satisfactory compliance. This item shall be deemed to have 
been satisfied when: 
(1) Suitable facilities are provided for adding make-up Avater 
as needed. 
ITEM 16 (g). CROSS-CONNECTIONS. No piping arrange- 
ments shall exist which under any conditions will permit seAvage or 
waste Avater to enter the recirculation system, or Avater from the 
recirculation system or pool to enter the make-up Avater supply. 
Public-health reason—Numerous outbreaks of Avater-borne 
diseases have resulted from contamination of AArater supplies 18 
through plumbing installations which allowed contaminated water 
or sewage to enter safe water supplies during adverse hydraulic 
conditions. 
Satisfactory compliance. This item shall be deemed to have 
been satisfied when: 
(1) No pipe furnishing water for the make-up water supply is 
physically connected to the recirculation system regardless of valve 
arrangements, unless an approved vacuum breaker is properly in- 
stalled on the make-up water line. 
(2) The make-up water line discharging directly to the pool 
has its point of discharge at least 6 inches above the pool overflow 
level. 
(3) The make-up water line discharging to a surge or balanc- 
ing tank has its point of discharge at least 6 inches above the rim 
of the tank. 
(4) The main drain line, and the filters’ backwash and filter- 
to-waste lines have a free-fall discharge to the sewer or drain at such 
elevation that a surcharged sewer or drain could not force contami- 
nation back into the pool or recirculation system. Provisions may 
be made, however, for directly connecting the main drain to the 
sewer or drain as a means of off-season drainage. 
(5) All other accessories to the recirculation system such as 
chemical solution pots, water-fed chlorinators, etc., are protected 
against back-siphon age into the water supply. 
ITEM 16 (h). CLEANOUTS. Cleanouts shall be provided at 
such points in the recirculation system as will enable obstructions, 
accumulations, etc., to be readily removed. 
Public-health reason—Unless stoppages in the recirculation sys- 
tem can be removed without undue expense or labor, the pool man- 
agement is inclined to operate the pool without recirculation. 
Satisfactory compliance. This item is believed to be sufficiently 
clear so that no interpretation is necessary. 
ITEM 16 (i). PIPING SYSTEM. The piping system shall be 
designed to reduce friction losses to a minimum. 
Public-health reason—An ample factor of safety in the pipe 
sizes of the recirculation system is necessary for the maintenance of 
the required turnover rate, even with allowance for the reduction 
in the carrying capacity of the pipes because of corrosion and 
scaling. 
Satisfactory compliance. This item shall be deemed to have 
been satisfied when: 
(1) Pipe capacities in general are at least twice the theoretical 
value. 
(2) Flanged joints or unions are inserted at intervals to per- 
mit any part of the system to be taken down quickly for cleaning or 
repairs. 19 
ITEM 17. ACCESS TO EQUIPMENT. Filters and other equip- 
ment shall be accessible. 
Public-health reason—Recirculation equipment systems that are 
difficult to inspect or service because of their location or arrange- 
ment are frequently neglected. 
Satisfactory compliance. This item shall be deemed to have 
been satisfied when: 
(1) The recirculation equipment is conveniently located for 
inspection and servicing. Special attention is called to the necessity 
of providing adequate head room above pressure filters. 
ITEM 18. pH DETERMINATION OUTFIT. Every pool shall 
be provided with an outfit for the determination of hydrogen-ion 
concentration. 
Public-health reason—As previously stated, the effectiveness of 
the disinfection process and the absence of skin irritation of the 
bathers are often dependent on the pH of the pool water. 
Satisfactory compliance. This item shall be deemed to have 
been satisfied when: 
(1) An approved outfit for the determination of hydrogen-ion 
concentration in the pH range 6.5 to 7.6 is provided. 
ITEM 19. RESIDUAL CHLORINE DETERMINATION OUT- 
FIT. Every pool shall be provided with an outfit for the determi- 
nation of residual chlorine. 
Public-health reason—The only method of being assured that 
the residual chlorine in all parts of the pool is within the proper 
limits is by means of a residual chlorine determination. 
Satisfactory compliance. This item shall be deemed to have 
been satisfied when: 
(1) An approved outfit for the determination of residual 
chlorine in the range 0 to 2 parts per million is provided. 
ITEM 20. EQUIPMENT ROOM. The equipment room shall 
be satisfactorily located and adequately drained. 
Public-health reason—Damp equipment rooms tend to cause 
excessive deterioration of portions of the recirculation equipment. 
If the room can be directly entered from the shower room or pool 
area, dirt would tend to be tracked into the showers or pool area 
by the operator. 
Satisfactory compliance. This item shall be deemed to have 
been satisfied when: 
(1) The equipment room is so located that it can not be entered 
directly from shower rooms or pool area. 
(2) The floor has a minimum pitch of 2*4 inches in 10 feet 
toward the drains with no low spots which will allow water to stand. 
(3) The equipment-room drains do not discharge to a sewer 
or drain which may surcharge onto the equipment-room floor. 20 
BATHER-PREPARATION FACILITIES AND APPURTENANCES 
ITEM 21. DRESSING ROOMS. Dressing rooms shall be sat- 
isfactorily designed, located, drained, equipped, lighted, and venti- 
lated. 
Public-health reason—Unsatisfactory dressing rooms with damp 
floors, overcrowding, poor lighting, poor ventilation, and inadequate 
or poorly designed equipment are factors contributing to inadequate 
bather-control, improper cleansing of the dressing rooms, and the 
spread of infectious diseases. 
Satisfactory compliance. This item shall be deemed to have 
been satisfied when: 
(1) The dressing rooms are located adjacent to the locker or 
check room and showers. 
(2) Floors have a minimum pitch of 3 inches in 10 feet to the 
drains with no low spots which will allow water to stand. 
(3) Floors are of smooth but nonslip finish, impervious to 
moisture, with no open cracks or joints. 
(4) The rooms are lighted so that all parts are easily visible 
for cleaning. 
(5) The rooms are ventilated so that they do not remain ex- 
cessively damp. 
(6) Hose bibs of 1-inch minimum size and served by not less 
than a 1-inch pipe are provided to enable the entire dressing room 
to be conveniently flushed by hose. 
(7) The material used for walls, partitions, furniture, etc., 
is such that it can be easily cleaned, and will not be damaged by fre- 
quent hosing, wetting, or disinfection. 
(8) Dressing-booth partitions have a minimum clearance of 
6 inches above the floor, and curtains, if used on the booths, are of 
sufficiently heavy material to discourage their use as a substitute 
for towels. 
ITEM 22. SHOWER FACILITIES. Adequate and satisfac- 
torily designed and located shower facilities, including warm water 
and soap, shall be provided. 
Public-health reason—The best-designed pool with proper oper- 
ation of the recirculation system can not be considered assuredly 
safe for swimming without proper bather-preparation. Provisions 
for warm showers to be taken in the nude with plenty of soap are 
essential so that each bather may wash off the residual body wastes 
which are deposited on the body's surface. These body wastes may 
contain pathogenic organisms which could cause pool bathers to con- 
tract an infectious disease. Without the showers an excessive 
amount of body pollution could be introduced into the pool, even 
though no bather actually became ill. 
Satisfactory compliance. This item shall be deemed to have 
been satisfied when: 21 
(1) Separate shower facilities are provided for men and 
women and are so located that bathers must pass from the shower 
room directly to the pool area. 
(2) Shower facilities are provided as follows: 
Pools used by groups, classes, or platoons on a regular 
time schedule of 1 hour or less have 1 shower for each 
4 bathers in the maximum class or 1 shower for each 
10 if the period is 2 hours. 
Pools with continuous bathing have a minimum of 1 
shower for each 40 bathers expected at the time of maxi- 
mum load. 
(3) The ceilings, walls, and floors of the shower room or area 
are constructed of impervious material not adversely affected by 
steam or water. 
(4) The floor is smooth, nonslip to bare feet, has no open 
cracks or joints, and has a minimum pitch of 3 inches in 10 feet 
toward the drains with no low spots which will allow water to stand. 
(5) A minimum of 5 gallons of water per shower per minute, 
having a temperature of not less than 90°F., is provided. Water 
from the discharge side of the recirculation-system filters may be 
used, provided special provisions are made to obtain adequate pres- 
sure, quantity, and temperature. 
(6) The showers are so designed that a proper mixture of hot 
and cold water may be obtained without danger of scalding the 
bather. 
(7) Liquid or powdered soap in suitable dispensing equipment 
is provided for each shower unit. 
(8) Shower booths are provided in the women’s shower room, 
the partitions of which booths will not be damaged by the shower 
water and will have a minimum clearance of 6 inches above the floor. 
(9) Shower rooms are adequately lighted so that all parts are 
easily visible for cleaning. 
(10) Shower drainage is discharged to an approved municipal 
sanitary sewerage system, or to sewage-disposal facilities approved 
by the State Sanitary Water Board. 
ITEM 23. TOILETS. Adequate, satisfactory, and properly 
located toilet facilities of acceptable design shall be provided. 
Public-health reason—Toilet facilities should be so designed and 
located that bathers are encouraged to use them while in the pool 
area. 
If bathers desiring to use the toilet facilities must cross areas 
which patrons in street shoes use, an excessive amount of dirt may 
be carried back into the pool area. 
The plumbing fixtures in a toilet may become the source of a 
contaminated water supply if they are not so protected that their 
contents can not be siphoned back into a safe water supply during 
unusual hydraulic conditions. 
Satisfactory compliance. This item shall be deemed to have 
been satisfied when; 22 
(1) Toilets known as “inside dry” for each sex are provided 
for the patrons iu tlie dressing area, to which toilets they may have 
convenient access without crossing floors or using fixtures wet from 
bathers. 
(2) Toilets known as “inside wet” for each sex are provided 
for the patrons while in the shower rooms or pool area, to which 
toilets they may have access without crossing areas used by persons 
in street shoes. 
(3) Fixtures are provided in the numbers specified below: 
(a) For pools not larger than 50' x 100' in area with 
a permissible bathing load not to exceed 700 persons: 
Inside Dry 
Inside Wet 
Men 
2 closets 
1 closet 
2 urinals 
1 urinal 
1 lavatory 
Women 
3 closets 
2 closets 
1 lavatory 
(b) For pools larger than 50' x 100' in area with a 
permissible bathing load of over 700 persons: 
Inside Dry 
Inside Wet 
Men 
3 closets 
2 closets 
4 urinals 
2 urinals 
2 lavatories 
Women 
4 closets 
2 closets 
2 lavatories 
(4) All fixtures are properly protected against back-siphon- 
age to the satisfaction of the State Department of Public Health. 
(5) All fixtures are so designed that they may be readily 
cleaned, and that frequent cleaning and disinfection will not damage 
them. 
(6) Urinals in the inside wet toilet are of a type which will 
not cause splashing of urine upon the feet and legs of bathers. 
(7) Toilet floors are constructed of impervious material with 
no open cracks or joints, have a smooth nonslip finish, and pitch not 
less than 3 inches in 10 feet toward the drains. 
(8) Partitions, walls, and ceilings are constructed of material 
not adversely affected by steam, water, or a disinfectant. 
(9) Toilet rooms or areas are lighted so that they are easily 
visible for cleaning. 
(10) Toilet rooms are ventilated so that no odor nuisance may 
exist. 
(11) Hose bibs of not less than 1-inch size, and served by not 
less than 1-inch pipe, are provided for convenient hosing of the toilet 
rooms or area. 
(12) Toilet-room sewage is discharged to an approved munici- 
pal sanitary sewerage system, or to sewage-disposal facilities ap- 
proved by the State Sanitary AYater Board. 23 
SPRAY POOL 
SPRAY POOL DEFINITION. A spray pool is defined as an 
artificial pool for use by children, into which water is sprayed but is 
not allowed to pond in the bottom of the pool. 
ITEM 24. MATERIAL. Spray pools shall be constructed of 
a permanently impervious material which shall have and retain a 
finish as smooth as possible that is nonslip to bare feet. 
ITEM 25. DESIGN, SLOPES. Spray-pool bottoms shall slope 
not less than 3 inches in 10 feet toward the drains. 
Xo obstructions such as raised drains, steps, or concrete gadgets, 
on which children may fall or become injured shall be placed in the 
spray-pool area. 
ITEM 26. DRAINS. The spray pool shall be equipped at its 
low point with an unvalved drain. 
The drain shall have a free-fall discharge to the sewer or storm 
drain so that contamination from a surcharged or clogged sewer can 
not be forced back into the spray pool. 
The drain shall be of such size and design that water sprayed 
into the pool will not pond in the pool bottom. 
ITEM 27. WATER SUPPLY. The water sprayed into the 
pool shall meet State Department of Public Health bacteriological 
standards for a safe drinking water. 
ITEM 28. HOSE CONNECTION. At least 1-inch minimum- 
sized hose bib served by not less than a 1-inch pipe, shall be pro- 
vided for cleaning the spray pool. 
ITEM 29. WALK AREA. The spray pool shall be entirely 
surrounded by a walk constructed of permanently impervious mate- 
rial which shall have and retain a finish as smooth as possible and 
nonslip to bare feet. 
DESIGN AND CONSTRUCTION FEATURES OF WADING POOLS 
WADING POOL DEFINITION. A wading pool is defined as 
an artificial pool with a maximum depth of not more than 36 inches. 
ITEM 30. MATERIAL. Wading pools shall be designed of 
a permanently impervious material which shall have and retain a 
finish as smooth as possible that is nonslip to bare feet. 
ITEM 31. LOCATION, DESIGN, SLOPES. Wading-pool bot- 
toms shall slope not less than 3 inches in 10 feet toward the drains. 
The pool shall be located so that drainage from the surrounding 
area will not wash contamination into the pool during rains. 
No obstructions such as raised drains, steps, or concrete gadgets, 
on which children may fall or become injured, shall be placed in the 
wading pool area. 24 
ITEM 32. OVERFLOW GUTTERS. An open-type overflow 
shall be provided around the entire perimeter of the wading pool 
with a maximum variation in elevation of 0.1 inch. 
The bottom of the overflow shall have a pitch to tne drains of 
not less than 3 inches in 10 feet. 
Where a wading pool is adjacent to a swimming pool, overflow 
drainage shall not be returned to the recirculation system. 
ITEM 33. FENCE OR BARRIER. A fence or other barrier 
shall surround the wading pool to prevent spectators from trespass- 
ing on the pool walk. 
ITEM 34. WALK AREA. The wading pool shall be entirely 
surrounded by a walk constructed of permanently impervious mate- 
rial which shall have and retain a finish as smooth as possible that 
is nonslip to bare feet. 
The walk shall slope not less than 3 inches in 10 feet toward the 
drains or overflow. 
ITEM 35. DRAINS. The wading pool shall be equipped at 
its low point with a drain. 
The drain shall have a free-fall discharge to the sewer so that 
contamination from a clogged or surcharged sewer can not be forced 
into the wading pool. 
The drain shall be of such size that the entire pool contents can 
be drained in 10 minutes. 
ITEM 36. INLETS. The inlets shall be of such size that the 
pool can be entirely filled in 1 hour, and shall be so located as to 
produce uniform circulation throughout the pool. 
The point of discharge of the inlets, when not served by a swim- 
ming pool recirculation system, shall be at least 6 inches above the 
pool overflow level. 
ITEM 37. MAKE-UP WATER. The water entering the wad- 
ing pool shall meet State Department of Public Health bacteriolog- 
ical standards for a safe drinking water. 
ITEM 38. DISINFECTION. The water in the pool shall have 
a chlorine residual of not less than 0.5 parts per million. 
ITEM 39. TOILETS. Separate toilet facilities for each sex 
shall be provided adjacent to the wading pool. 
These toilet facilities shall meet the design features specified in 
Item 23. 
ITEM 40. HOSE CONNECTIONS. At least one 1-inch mini- 
mum-sized hose bib served by not less than a 1-inch pipe shall be 
provided immediately outside the wading pool enclosure. 25 
STATE OF ILLINOIS—County of Sangamon 
I, Roland R. Cross, M. D., Director of the Department of Public 
Health of the State of Illinois, do hereby certify that the foregoing 
is a true copy of the forty (40) Minimum Sanitary Requirements 
for Swimming Pools and Bathing Places, in said State, promulgated 
under date of May 1, 1945. 
IN WITNESS WHEREOF, I hereunto set my hand and Official 
Seal of the Department of Public Health of the State of Illinois, this 
first day of May, 1945. DESIGN AND ADDITIONAL MISCELLANEOUS 
SUGGESTIONS 
GENERAL 
This section of the bulletin sets forth certain design features 
which it is believed should receive consideration in any proposed 
installation or improvement to an existing installation. The various 
items discussed may have no direct sanitary significance, but will aid 
in achieving the most desirable design to fulfill the particular pur- 
pose for which the pool is intended. Many of the items that should 
be considered in an indoor pool design are omitted here in order to 
encourage the designing engineer or architect to discuss these mat- 
ters personally with engineers of the State Department of Public 
Health. 
POOL AND POOL AREA 
Outdoor Pool Location. The location of water mains, electric 
power lines, and sewer and drainage facilities should all be consid- 
ered in selecting the proper location for a pool. Spectators in large 
numbers are more frequently present at the outdoor pool in the after- 
noon; hence, it is desirable to provide for them on the west side of 
the pool with their backs to the sun. For this reason it is best to 
have the pool, if typical, with its long dimension in a north and 
south line. In many installations along heavily traveled highways, 
the bathhouse has been located away from the highway with the 
pool in the foreground, with excellent results from an advertising 
standpoint. 
Size. Of all the shapes which have been evolved, undoubtedly 
the rectangular one is the most commonly used and perhaps the 
most popular. Size, which should be adapted to potential bather 
demand, will to a great extent determine the shape. Most existing 
outdoor pools are too large. Size alone can not provide the degree 
of sanitation which is now required. It is more desirable to build 
a complete unit with more permanent material and having adequate 
water-treatment equipment, than to attempt to construct a larger 
unit with many of the essential details lacking or limited due to size 
of unit or lack of funds. 
A pool may meet all of the accepted sanitary and safety require- 
ments and still be uneconomical in size and in the use of material, 
from a structural standpoint. Authorities should, as far as possible, 
allow only those pools to be constructed which are of such economi- 
cal size that their continued operation will be justified. 27 
Dimensions. Dimensions, except as they handicap economical 
control and supervision, are a matter to be determined largely by 
competitive requirements, the bather demand, and the area avail- 
able for a particular installation. 
Suggested lengths (to meet competitive requirements) : 
60 feet (20 yds.) 5 lengths—100 yds. ...11 lengths—220 yds., etc. 
75 feet (25 yds.) 4 lengths—100 yds., etc. 
82.02 feet (25 meters) 4 lengths—100 meters 
120 feet (40 yds.) 100 yds. 2% lengths (not especially desirable) 
150 feet (50 yds.) 50 yds., straightway 
164.04 feet (50 meters—54.58 yds.) 50 meters, straightway 
300 feet (100 yds., straightway) 
330 feet (100+ meters—110 yds.) 
Suggested Desirable Dimensions. The following combinations 
of dimensions are suggested, based upon competitive requirements and 
ease of operation: 
30' x 60' 
25'x 75' 
30' x 75' 
35'x 75' 
40'x 75' 
50'x 150' 
60'x 150' 
75'x 150' 
50'x 165' 
60'x 165' 
75'x165' 
30' x 82' + (25 meters) 
35' x 82'+ 
40' x 82'+ 
40' x 120' 
50'x 120' 
60'x 120' 
Suggested Multiple Pool Dimensions. 
Diving Pool 50' x 60' 
60' x 75' (For high platform diving) 
Competitive Pool 40' x 82.02' 
60'x 165' 
General Pool 50' x 165' 
60'x 165' 
75'x 165' 
82.02' x 300' 
82.02' x 330' 
Width. In pools where competition may be in effect the pool 
width should provide 6-foot lanes for four competitors (minimum). 
In strictly competitive pools the lanes should be a minimum of 7 feet 
wide. 
Depth of Water. The large majority of swimmers and bathers, 
excluding small children and divers, desire water of a depth suitable 
for wading (3' to 5'6"). To obtain a 3-foot depth in the shallow 
area it is necessary to have a pool 3 feet 3 inches to 3 feet 6 inches at 
the overflow. From 3 to 5 inches of water, except in pools with closed 
systems, are lost to the drains after a relatively few bathers and 
swimmers enter the pool. 
Proportion of Deep and Shallow Water. Some authorities rec- 
ommend that the area of shallow water, 5 feet or less in depth, 28 
should be 80 per cent or more of the total area of large outdoor 
pools. Such proportioning must be considered in relation to the 
pool volume, the bathing load, the recirculation system, etc. Insuf- 
ficient information is available at present to make any definite rec- 
ommendations on this point. 
Deep Water. Deep water is needed only insofar as it is re- 
quired to meet the demands for water polo and diving. The fol- 
lowing depths and area are, in general, required for diving: 
Depth 
Area with 51/) feet 
Springboard 
Minimum 
Recommended 
deptli or more 
1-meter 
8 feet 
914 feet 
260 sq. ft. (20' x 13') 
325 sq. ft. (25' x 13') 
3-meter 
9y2 feet 
11 ' feet 
high dive 
12 “ feet 
14-15 feet 
468 sq. ft. (36' x 13') 
When various combinations of low and high springboards are 
used, an overlapping of these areas is possible within reasonable 
limits. 
Off-Center Hopper. In pools of moderate size where one high 
springboard and one low board are used, an “off-center hopper" 
bottom with the deepest point under the high board represents the 
“latest” in adaptation of the bottom contour to the diving require- 
ments. A saving in excavation, material, and water to be treated 
results from this particular bottom contour and the deep water is 
provided where needed. 
Proportioning Pool Area to Expected Load. In the design of 
an artificial pool, due allowance must be made for the number of 
bathers who may be expected at the time of maximum use. In com- 
puting the area which must be provided, it is recommended that the 
pool be divided into 3 zones, and the area of each computed 
separately. 
It is apparently the consensus of opinion that an area extending 
10 feet from the extremity of a diving board or tower should be 
considered as reserved for divers, and that no more than 2 or 3 
persons should be permitted in the water in this area at one time 
while diving is in progress. About three times that number will be 
on the shore or diving platform awaiting their turn to dive. Twelve 
persons is, therefore, the maximum number which may be permitted 
for the area within a 10-foot radius of each diving board or platform. 
The consensus of opinion of swimming pool operators is report- 
edly that the space required by a swimmer might fairly be expressed 
as five-fourths the square of his height, and that, on an average, two- 
thirds of the swimmers present would be iu the pool at the same 
time. On this basis the average space requirement for au adult 
swimmer is 36 square feet and, allowing for one-third of swimmers 
on the shore, an average of 27 square feet should be provided for 
each swimmer who may be expected to be present at time of maxi- 
mum load. 29 
In computing the area to be provided for persons who do not 
swim, we must take into consideration the character of the pool. 
At indoor pools and small outdoor pools, this area should probably 
be included with the swimming area and the crowding limit com- 
puted on this basis. x\t large outdoor pools where a considerable 
proportion of the water is shallow water, we may assume that 50 
per cent of the nonswimmers would be on shore. The average space 
allowance for each nonswimmer in the water is approximately one- 
half that of the swimmer in deep water. Combining these factors, 
an allowance of 10 square feet per bather should be allowed for 
this portion of the pool. 
Accuracy of Competitive Course. For competitive purposes 
and where the pool may be used at any time for swimming events in 
which records may be established, care should be taken to assure 
that the distance measured from wall to wall will be the full required 
distance and not fall short by even a fraction of an inch, in which 
case the record would not be allowed to stand as official. 
Subsurface Drainage. All pools should have adequate subsur- 
face drainage not directly connected to a sanitary sewer. When- 
ever possible the pool should be located at such elevation that it will 
not be necessary to use a sump and pump. When gravity subsurface 
drains are not possible, the drainage should be into a sump, and 
provisions made to insure its proper functioning during the off- 
season of an outdoor pool. 
Proper provision for subsurface drainage will prevent damage 
to the floor due to freezing, and damage to the pool structure due to 
hydrostatic pressure (when pool is emptied). In pools not equipped 
with proper subsurface drainage, pollution from sanitary sewer lines 
which pass near the pool structure is often possible. 
Adjustable Courses. Several types of adjustable courses have 
been worked out with varying success. In the most desirable design 
the pool proper has a maximum course possible for 50 meters (54-j- 
yards). Two movable barriers which divide the pool into three 
separate sections are used. Three pools, one for diving, one for 
competition, and one for beginners, are available. With this de- 
sign, courses which cover all the recognized distances are possible. 
Twin Pools. Twin pools providing two separate pools and 
rooms, with a removable wall or barrier, have not, to our knowledge, 
been worked out satisfactorily to date, for mechanical reasons. 
Pool Markings. Two types of pool markings should be pro- 
vided, as a usual thing. One concerns the depths and relates to 
safety, the other concerns competition. Depths in pools and bathing 
areas should be plainly marked in a conspicuous manner. This can 
he done in tile pools by incorporating the information in the design. 
In pools where competition will be the usual thing, lanes should 
be provided to guide the swimmers when using strokes in which the 30 
face is submerged. The lanes should be so situated that the swim- 
mer swims over the marker or lane, not between the lanes. 
Unless these lanes are constructed by the use of tile or cement 
of a different color (dark) they will not be permanent or satisfac- 
tory. Painting lines on the bottom of the pool is unsatisfactory. 
Lanes should be at least 6 feet wide, preferably 7 feet in competitive- 
event pools. Dive-foot lanes, which are commonly used, result in 
crowding competition, especially in the breast-stroke events. The 
lanes should end at a point approximately 4 to 6 feet from the end 
of the pool and should be marked with a short transverse line. 
Springboard and other equipment should be so placed with ref- 
erence to the lanes that the swimmers will be able to take off directly 
over the line or marker. 
If the dimensions of a pool are in yards, then the standard com- 
petitive metric distances should be designated in the tile or concrete 
with permanent nonrusting markers. The reverse should be done 
if the pool dimensions are in meters. 
The outlet of the pool should also be plainly marked by a black 
or dark-colored circle, unless outlet grating is of conspicuous color- 
ing. The depth of water at the deepest point and at the 5-foot point 
should be conspicuously marked on both sides of a pool having deep 
water at one end. Markings showing depths in 1-foot increments 
are desirable. In large pools with deep water in the middle only, 
the 3- and 5-foot deptli lines should be conspicuously marked on the 
bottom and also designated by surface floats. 
Surface Markers for Competition. In pools frequently used for 
competition, provision should be made for installing surface lane 
lines. The lane markers when properly designed and installed also 
reduce the wave action and result in more satisfactory competitive 
conditions. 
Slope of Bottom. The slope of any part of a pool where the 
water is less than 6 feet deep must not be more than 1 foot in each 
15 feet. 
The bottom of the floor should slope definitely to the main drain 
or outlet. Deep water, except as required for safety in diving, 
should be limited to areas where it is actually needed. Deep water 
when provided in excess of this requirement is a decidedly uneco- 
nomical use of pool structure and water. The adaptation of the 
pool bottom to the diving needs will result in a “double-spoon'’ or 
“hopper” bottom. Any flat areas on the pool bottom offer excellent 
lodging places for deposits and should be avoided. Sudden changes 
in depth should not be made where the water is less than 6 feet deep. 
With a “hopper” type of bottom it is possible to provide deep water 
where it is really needed. With this type of construction, deposits 
which accumulate on the bottom of the pool will tend to work their 
way to the deep water, where the outlets are located. 
Ledges, Obstructions, Barriers. The use of barriers or fences 
between the various depths is not recommended, unless they can be 31 
constructed in such a manner as not to prevent the movement of 
deposits toward the outlet. Steps or flat ledges are not recom- 
mended, but when used should pitch very definitely so that there 
will be no accumulation of objectionable deposits. 
Steps and Ladders. Steps or stairways for entering and leav- 
ing the pool should be of such construction as to minimize danger 
of accidents. Ladders or stairways should be located at one or both 
sides of the deep end of the pool. If the distance from the bottom 
of the pool to the runway is more than 2 feet, a ladder or steps 
should also be placed at the shallow end of the pool. Treads of 
ladders or steps should be of nonslip material. 
Ramps in lieu of stairs are to be preferred in all cases where 
transition from one level to another in the pool or pool area is 
required. 
Pool Lining. Tile or glazed brick lining is recommended for 
all indoor pools and for small outdoor pools. White cement smoothly 
finished is satisfactory for large outdoor pools. When white con- 
crete is used, protection should be provided during construction to 
prevent staining, soiling, and discoloration and irregularities due 
to the wires, reinforcement rods, and form marks. Dirt does not 
show on asphalt or other similar dark material, and such materials 
are not suitable for pool lining. 
With the excessive abrasion on the floor from the bathers’ feet 
and the suction-cleaner brush and wheels, most paints have been 
found unsatisfactory, although certain of the chlorinated rubber 
type have been successful. Certain dark-colored paints or cover- 
ings have demonstrated some degree of permanence but because of 
their dark colors are objectionable. Plaster coats have been found 
generally unsatisfactory for pool linings. 
Nonslip Walks, Mats. The most common type of accident 
around a pool is a fall. All areas used by bathers in bare feet should 
be nonslip to bare feet. If funds are available, tile of the nonslip 
variety should be used. Tiles are nonslip either as the result of 
having definite abrasive material included in their composition, or 
by virtue of an uneven surface (ridge-raised portions). Con- 
crete walks and floors can be made nonslip by the proper methods 
at the time of their construction. After they have hardened they 
can be made nonslip but at the cost of spoiling the finish as far as 
ease in cleaning is concerned. 
Two methods are commonly used to give a nonslip finish to 
concrete and at the same time provide a surface which can be 
cleaned with reasonable care. Of these methods the brush finish is 
the least desirable because, while it is definitely nonslip when the 
surface is clean, the surface when exposed to service that is usual 
in pools and dressing areas becomes very slippery and unsafe. The 
more desirable finish, which is known as the “lift” or “suction” 
finish, is produced as follows: The surface is troweled smooth, 
then an object such as a block of wood covered with burlap or 32 
canvas is pressed down and then lifted up quickly. This produces 
little ridges and striations, and when properly done results in a 
surface which is fairly nonslip, easy to clean, and retains this nonslip 
quality to a fair degree even when dirty. In addition to this, mate- 
rials of an abrasive nature may be added to the concrete. 
Existing pool facilities which have been constructed with slip- 
pery terrazzo floors may be made nonslip by the application of 
certain cleaning materials. The use of acid for this purpose is not 
recommended, because the resulting excessive deterioration of the 
surface makes it difficult to clean these surfaces and keep them 
clean. 
Concrete coated with a paint to which sand or some abrasive 
material has been added will produce a nonslip surface, but this 
treatment makes the floor very difficult to clean. In many cases it 
is better to remove the paint and use certain strong cleaning pow- 
ders at frequent intervals and not allow the floor to be repainted. 
Bush hammering the floor surface or roughening it with hand 
tools is often done, but probably represents the least desirable 
method of trying to overcome defects in original construction. 
The use of rubber mats, wooden mats, and other materials of 
this nature is permissible in pools and pool facilities to cover floors 
which have been imperfectly constructed as to nonslip qualities, 
but this procedure should be followed only when no other solution 
of the problem can be found. In such cases the daily removal of 
all mats, runners, etc., is required and it will be necessary to pro- 
vide for their daily disinfection with acceptable disinfectants. 
Mats (cocoa, rubber, etc.), we believe, are responsible for the ma- 
jority of infections to bathers’ feet. 
Underwater Coaching Windows. Provision for viewing the 
form and movements of competitive swimmers can be made in pools 
where competition is a considerable item, by installing clear glass 
panels below the level of the water, and making access easy to the 
coach or teacher through an “access tunnel.” 
Winter Protection. Many pools which have tile included in 
their design have been provided with covers which keep out snow 
and water and, when necessary, provide heat to protect the pool 
structure from the deleterious effects of extreme winter tempera- 
ture. 
Portable Pools. Pools which can be transported from place 
to place where needed for competition or exhibition purposes, and 
which are provided with portable water-treatment apparatus, are 
now available. 
Underwater Pool Entrance. On pools used for exhibition and 
entertainment purposes, an underwater entrance is very effective 
and its construction is not particularly difficult. 
Lighting. When natural light is provided by windows or sky- 
lights for indoor pools, the sky light area should be equal to at 33 
least one-half of the area of the pool and walks. Underwater lights 
are recommended for pools which will have considerable use after 
sundown. They should be designed so as to prevent the possibility 
of accidents. In indoor pools, lights should be protected or recessed 
to prevent breakage. 
Heating. All heating units should be isolated or protected to 
prevent injury to bathers. The heating units should be capable 
of maintaining a temperature between 70°F. and 82°F. Thermo- 
static control of the temperature is desirable. 
Acoustics. All indoor pools should receive acoustical treat- 
ment when necessary. Design, materials, and construction should 
be used which will prevent reverberation of sound which may re- 
sult in lack of control on the part of the instructors or attendants. 
Walk Areas. In outdoor pools the walk area should be pro- 
tected at the outer edge with a curb to prevent litter and dirt, 
rodents, snakes, etc., from obtaining access to the pool area. 
A curb at the edge of the pool possesses distinct advantages. 
Such a curb prevents accidental flushing of walk accumulations 
into the overflow or pool. Curbs, if properly constructed, present 
no physical hazard to the bather. Walk drainage should, in no 
case, go into the sanitary lines which drain the pool overflow, and 
should in all cases he run to waste. Walks should be as spacious 
as possible, because a majority of the patrons will be found on the 
walk areas. By increasing the walk areas and cutting down pool 
areas, considerable economy in original cost and operation may 
be effected with no sacrifice of usability. 
If a curb around the pool at the overflow edge is used when 
the walk drainage is toward the pool, then adequate and properly 
located drains are necessary to prevent water from collecting on 
the walk adjacent to the curb. This curb prevents the litter and 
dirt on the walks from being carelessly hosed or flushed into the 
pool. It also gives a better take-off for divers. Certain objections, 
from a safety standpoint, to this curb may he overcome by design- 
ing it with sufficient height and with a width of at least 8 inches. 
The top surface of this curb should be of nonslip construction and 
the “take-off” edge rounded to enable the diver’s toes to properly 
retain their grip on the edge. 
Not only has white concrete been used for pool bottoms, but 
colors have been used with artistic effects on pool walks, curbs, etc. 
Hose Connections. Hose connections should be recessed, or so 
located as to prevent accidents. Hose should be of the type adapted 
to excessive abrasion and necessary hard usage. 
Overflows. When the open-type overflow (See illustration A.) 
is used, the design should be such that the diver is not tempted to 
use as a take-off the actual overflow edge instead of the edge where 
the overflow and walk meet. This can be accomplished by limit- 
ing the vertical distance “y,” from the maximum water level to 34 
the top of the curb, to a value not less than 0.6 of the horizontal 
distance “x” of the overflow. However, this ratio does not apply 
to cases in which the “y” distance is less than the recommended 
minimum value of 6 inches and the “x” distance exceeds the maxi- 
mum of 12 inches. 
When semi-recessed overflows are used they should be of such 
design that bathers’ limbs will not be caught in them when climb- 
ing out of the pool. In pools with the open type of overflow, start- 
ing blocks or pedestals may be provided for competitors but they 
should be so constructed that they will not interfere with the 
proper runoff of the overflow water. 
All drains or openings in the overflow should be provided with 
easily removable, coarse gratings or strainers. The drain pipes 
should be 2% inches in diameter and the gratings should be twice 
the cross-sectional area of the drain outlet, and both should be so 
designed that they may be quickly serviced for repairs. 
Consideration should be given to arranging the piping in such 
manner that with minor changes the overflow may be discharged 
to waste, to the balancing or surge tank, or to the recirculation 
pump suction. 
Diving Equipment. The type of diving equipment, its location, 
etc., for the most part involve problems of safety. The diving equip- 
ment should be limited to standard types and heights of installa- 
tions. Springboards are located at two heights, 1 meter (1.1 
yards) and high boards at 3 meters (approximately 118 inches 
or 3.28 yards). If these two regulation boards are provided, lower 
and intermediate heights may be included. For diving over 3 meters, 
solid platforms 10 meters (32.8 feet or 10.94 yards) and 5 
meters high are standard. The 5- and 10-meter platforms, when 
necessary, may be placed one above the other. An over- 
hang over the water’s edge of at least 36 inches should be provided 
on the 10-meter platforms and not less than 18 inches on the 5- 
meter platforms. Permanent diving platforms should not be per- 
mitted over a height of 10 meters in a public pool. 
The main hazard in diving from high platforms lies in the 
manner of access to the platform. Stairs or steps of an approved 
design adapted to this particular use should be provided. 
Springboards should be located not less than 8 feet center to 
center, and so that all diving traffic (aerial and water) is in the 
same direction. A low springboard should not be located directly 
below a high board. At least 13 feet of head room must be pro- 
vided above the highest board to avoid accidents. 
Concrete has been used very effectively and artistically to 
construct diving towers and platforms. Several designs of adjust- 
able fulcrum diving boards are available which make it possible 
to obtain, by a quick adjustment, any desired “reaction time.” 
Floats, Rafts, Piers. Equipment such as floats, wheels, slides, 
etc., if used, should be located in such portions of the pool that they 
will not interfere with competitive or general swimming requirements. 35 
SMALL POOL ADAPTED FOR HIGH 
AND LOW BOARDS WITH OFF- 
CENTER HOPPER BOTTOM. 
SUGGESTED OPEN TYPE OVERFLOWS 
FOR EXPLANATION OF RATIO 
BETWEEN X8.Y SEE ITEM I© 
ILLUSTRATION -A 36 
Floats should be of such construction that it is not possi- 
ble for divers and swimmers to be caught under them. This can 
be accomplished either by providing a minimum space of not less 
than 12 inches beneath the floor of the float when it is crowded 
to capacity, or by constructing the float so that underwater access 
can not be obtained. When floats, buoys, or life lines are used 
to mark the boundary lines between shallow and deep areas, they 
should be so constructed that bathers will not submerge them by 
hanging upon them. A type of marker or line which will remain 
exposed even when supporting a large number of bathers should 
be provided. 
Fences, Barriers. Only by providing‘a real barrier around a 
pool and its walk area can the pool be made reasonably safe from 
a. sanitary or safety standpoint. In country club pools, whenever 
possible, the pool should be located where building, impenetrable 
hedges, etc., will encircle the pool area without the use of unsightly 
fences. During the portion of the day when supervision is not pro- 
vided in a pool of this type, a temporary barrier or restraining line 
should be provided to warn persons against entering the pool area. 
Inlets. Inlets should be located not more than 10 to 15 inches 
below the overflow level of the pool. Consideration should be taken 
of the fact, when determining inlet locations, that the greatest pool 
loads are in shallow water and that for the most part these patrons 
are probably the most susceptible to infections. The question of 
velocity at the inlet orifice is a debatable one with valid arguments 
on either side. In large pools, we believe, the inlets should have a 
directional flow. Inlets having a free fall into the pool are often 
objectionable because of the noise, especially indoors. Multijet 
inlets which are designed to distribute the water in a great many 
directions at increased velocity are being used with success. If 
inlets are provided with gratings, such gratings should be designed 
so as to avoid undue friction and to avoid presenting a hazard to 
swimmers. 
The use of sprays, nozzles, etc., for the purpose of temperature 
regulation should be confined to periods during which the pool is 
not in use. When such operation dissipates the chlorine residual, 
the latter must again be brought up to the required content be- 
fore bathers are allowed access to the pool. Make-up water from 
a spray, nozzle, or fountain may be introduced into the pool, but 
unless properly filtered will adversely affect the clarity of the pool 
water. 
Outlets. In a few cases pools have been designed for fresh 
water or repurified water to enter at the deep points and overflow 
through outlets or overflow gutters in the shallow portion. It is 
believed that there may be some advantage in having flow through 
the pool in this direction, thus permitting floating matter and dirty 
water from the more crowded shallow area to be carried off more 
rapidly. However, during periods when the pool is not being used, 
normal recirculation has very definite advantages. 37 
The covering or grating should be of such design as to prevent 
bathers’ fingers from being injured, and should have suf- 
ficient weight or be secured in place so as to prevent easy removal by 
prankish swimmers. The outlets should be so marked as to be 
plainly visible from the pool walks. 
Diving Masks for Underwater Work. Diving masks and 
other necessary equipment have been available for some time for 
use in large pools for cleaning the bottom drains, using suction 
cleaner, etc. 
RECIRCULATION SYSTEM AND APPURTENANCES 
Piping System. A sump and blow-off should be provided at 
the lowest part of the system to permit removal of any accumulat- 
ing iron rust. Openings should be provided for insertion of gauges 
to permit vacuum or pump suction and pressure at discharge to 
be determined, should a study of the recirculation system be de- 
sirable. Tt is advisable, also, to make provision for insertion of 
Pitot tubes or meters for checking the actual volume of water 
passing through the system under working conditions. Other re- 
quirements for piping are discussed under the heading “Inlets 
and Outlets.” 
Access Tunnel. It is very desirable to provide easy access to 
piping, and this can be accomplished by including in the design 
a tunnel extending around the pool. 
Hair- and Lint-Catcher. The best type of hair-catcher con- 
sists of a metal chamber containing a removable cylindrical strainer, 
so arranged that the water passes through the strainer from the 
outside. The cylinder and housing should be of noncorrosive 
metal. Hair-traps should be so constructed that they can be quickly 
taken down for cleaning by loosening two or three wing-nuts. 
Proper valves should be provided to prevent flow of water through 
the strainer while cleaning. 
Pumps. Centrifugal pumps are preferable for swimming pool 
circulation, although plunger pumps are sometimes used. Electric 
drive is also preferable. When pipe lines from suction cleaner 
lead to pump suction, a pump which will develop good vacuum 
must be used. When designed to operate with multiple-unit filters, 
it is advisable to have pumps in duplicate, with proper cross- 
connections to permit one filter to be washed with the effluent from 
another. If filters are located at an elevation higher than the water 
line of the pool, a check valve must be placed on the pump suc- 
tion. If possible, the installation should include a duplicate pump 
and motor with cross-connection making it possible to operate the 
suction cleaner, or to wash one filter with the effluent of another 
while the recirculation system is in operation. 
Water-Heater. In northern climates some method of heating 
the water is essential for indoor pools. Blowdng steam directly 38 
into the pool, as is practiced in some instances, or heating-coils 
placed directly in the pool are not recommended. A heater de- 
signed to heat all or a part of the circulation water is preferable. 
In designing a heater, ample surface for heat interchange must be 
provided. Such a heater may be designed for use with steam or 
hot water. Automatic thermal control is desirable. Provision 
should be made for easy removal of the heater parts for cleaning. 
Temperature Control on Outdoor Pools. Pools located where 
the water supply comes from a surface source whose temperature 
during the summer is too high to keep the pool temperature below 
80° by the addition of make-up water, may use a “low grade” 
water (for example, extremely high in iron), not suitable without 
extensive treatment for use in the pool, but of a temperature con- 
siderably lower than the pool, by jacketing the pool recirculation 
lines and pumping the undesirable water of ground temperature 
through this jacket. Copper pipes will increase the effectiveness 
of this “heat exchanger.” 
Thermometers. At indoor pools a fixed thermometer should 
be placed on the recirculation line beyond the heater and another 
near the outlet of the pool. At outdoor pools one thermometer is 
usually sufficient. Thermometers should be accessible and have a 
type of scale that is easily interpreted. 
Testing the System. After the recirculation system has been 
installed and the various units have been tuned up, a test of the 
hydraulic properties of the entire system and of each integral unit 
should be made. In such a test the velocity in the piping system 
at various points, the discharge capacity of each filter and each 
pump, the velocity and volume of wash water in each filter, and 
the rate of discharge at each pool inlet should be determined under 
actual working conditions with the pool at normal working level. 
The full data of this test should be a matter of permanent record 
for future comparison. A similar test repeated at least once a year 
is desirable. 
Chemical Feed. Positive-feed chemical machines are far pre- 
ferable to alum and soda ash pots and their use is recommended. 
Point of application should be as far as possible ahead of the filters, 
and generally the most desirable point is in the suction of the re- 
circulation pump. In addition to the longer reaction time, there 
apparently is an advantage in the more thorough mixing obtained. 
“Treatment sumps” are desirable and should be included in new 
pool designs, and provisions made for the application of the co- 
agulants in such sumps. These sumps also receive the make-up 
water, described later. AVhere possible, mixing and coagulation 
basins would be desirable. In some pools, soda ash addition direct 
to the pool by hand has been preferred to soda ash pots. 
Filtration. Both pressure and gravity filters can be used on 
pools. However, the pressure type is by far the most generally 39 
used. Gravity filters are commonly used on the larger installations 
where the pool capacity is greater than one-half million gallons. 
However, general requirements for filtration are the same for both 
types. 
Pressure filters are of two types, horizontal and vertical. The 
vertical types are generally used on the small-sized pools up to 400,- 
000 gallons in capacity, and the horizontal type on pools ranging in 
capacity between 300.000 and 1,000,000 gallons. Both vertical and 
horizontal types are used to best advantage in groups of 4 (not 
less than 3) to obtain the necessary wash rate without the use of 
additional pumps. If washing with the recirculation pump is not 
feasible, one alternate method is to install a wash-water pump of 
higher capacity. A suction well or small elevated feed tank, sup- 
plied with water from the public water supply, can be used to supply 
water to the pump. Over-rim inlets from the public water system 
to the well or tank should be used to prevent cross-connections. 
Apparent latitude in the character of filter sand is possible with 
satisfactory results. In general, two types of sand are used, the 
irregular, sharp variety and the more spherical grains. The sharp, 
irregular variety may, because of its shape, have greater efficiency 
in the filtration of the water passing through the filter bed, but more 
difficulty is encountered in removing the accumulations during back- 
washing than in the case of the rounded grains. There also appears 
to be a tendency of the irregularly shaped particles gradually to 
become round, due to accumulations and abrasions during washing 
and filtration. Permeability of a filter bed, which is of extreme 
importance in its proper clarification of the water, is apparently 
affected by the viscosity of the water to be filtered and the gradua- 
tion, size, and shape of the filter media. Considerable thought 
should, therefore, be given to this important part of swimming pool 
filtration equipment. 
Surface Wash on Filters. The surface wash on filters, which 
many believe effects economy in the use of wash water while at the 
same time making possible more effective cleansing of the filter bed, 
should be equally effective on swimming-pool pressure filters as on 
gravity types. Surface wash pressure should be 10 pounds per square 
inch or more at the jet to give sufficient velocity. Orifices of three- 
sixteenth- or one-fourth-inch and a rate-of-flow of about 3 gallons 
per square foot of filter area per minute are recommended. 
Surge and Overflow “Balancing” Tanks. Overflow reservoirs 
which prevent the loss of 4-5 inches of water, which takes place in 
the typical “open type” overflow pool when a class or sizable group 
of swimmers enters the pool, have been used successfully. This 
water, which ordinarily is lost to the sewers, enters these tanks, is 
returned to the pool at intervals, and sufficient make-up water is added 
to flush off surface accumulations. 
In pools so equipped a considerable saving is effected in heat 
and water, and the frequent overflowing results in a safer and more 
attractive pool. 40 
- ELEVATIOM OF EQUIPMENT — 41 
Where overflow drains are discharged to a closed recirculation 
system, they may be piped to a balance tank which in turn is con- 
nected to the pump suction, with the tank so designed that surface 
oils and accumulations may be discharged to waste. Incidentally, a 
balancing tank, whether connected to receive overflow gutter dis- 
charge or placed in any recirculation system, has two other useful 
purposes: (1) It provides an excellent place for introduction of 
chemicals into the system; (2) it may be used as a surge tank to 
overcome the tendency to cross-connect the recirculation system 
with the public water supply. It is recommended that consideration 
be given to installations of balancing tanks in connection with pool 
recirculation systems. 
When a surge tank is installed for receiving make-up water 
only, it should be placed, whenever practical, so that the maximum 
level of its contents will correspond to the elevation of the pool at 
the overflow edge. When not at pool level the pump connection to 
the pump suction should be equipped with a check valve. The surge- 
tank float (when tank is located at pool level) may be set to main- 
tain a definite level, which should be at a point even with the over- 
flow edge of the pool. Whenever possible, the make-up water con- 
trol, when not automatic, should be so located as to be convenient 
for the operator. 
Make-Up Water, When the water supply for a pool contains 
large quantities of calcium bicarbonate, and especially when such 
water must be heated for use, difficulty is often experienced in main- 
taining clear water in the pool by the usual methods of coagulation 
and filtration. To a certain extent this difficulty may be overcome 
by passing the alum-treated water through a properly designed 
coagulation and sedimentation basin before filtration. Where the 
installation of a proper coagulation basin is impracticable, it is sug- 
gested that water-softening apparatus of the zeolite or base- 
exchange type be installed as an adjunct to the recirculation system, 
to permit the calcium content of the pool water to be reduced to a 
reasonable amount. 
Water meters should be included in all pool installations on the 
make-up water supply line to assist in checking proper operation, 
water consumption, etc. Meters should be located where they are 
easily accessible for reading. 
Closed Systems. For reasons of economy and other considera- 
tions, the installation of so-called “closed systems” is permissible, 
provided certain conditions are met. This type of layout will have 
doubtful value on outdoor pools where the temperature is such 
that vast quantities of make-up water are required to keep the pool 
below 80°F. In cases where the water supply has some chemical 
content which requires special treatment, this type of design will 
have value. If the temperature-control is otherwise satisfactory, 
it will be possible to keep the make-up requirements at a minimum 
necessary to replace water lost by evaporation, carried out by 
bathers, etc. 42 
Temperature-control in a closed system may be worked out by 
the use of a heat-exchanger, using a low-temperature supply of pos- 
sibly unsatisfactory quality, to maintain the proper temperature in 
the pool. The system may also use this same source of water for the 
pool by providing satisfactory treatment. Sprays or fountains may 
also be used for temperature-control. In the latter case, however, 
the disinfection process must be adapted to meet this situation be- 
cause many believe aeration tends to remove the cholorine residual. 
Chlorine-Ammonia. Because the use of ammonia in conjunc- 
tion with chlorine produces chloramine, a product of greatly re- 
duced disinfecting power, the addition of ammonia in any form is 
not recommended. Most pool waters in regular use will contain 
some ammonia or other organic nitrogen compounds which for all 
practical purposes are active dechlorinating agents. The addition 
of ammonia makes a bad situation worse. All measures which help 
to keep the ammonia content of the pool water at as low level as pos- 
sible will increase the efficiency of chlorination. A high degree of 
bather cleanliness is an important factor in the reduction of the 
ammonia content of the pool water. 
Other Disinfectants. Other agents which have been proposed 
as disinfectants for swimming pools are ; 
1. Ultra-violet light 
2. Ozone 
3. Silver 
4. Bromine 
None of these is recommended for one or more of the following 
reasons: 
1. Slow disinfecting action 
2. No residual disinfecting action 
3. Lack of adequate control 
4. Unsatisfactory or expensive equipment required 
5. Inadequate research 
Location of Equipment. Often there is a psychological advan- 
tage in locating disinfecting equipment within view of the patrons. 
Chlorinators located in populated buildings such as clubs or schools 
should be suitably housed to prevent escape of gas due to accidental 
leak. A gas-tight, rust-resisting enclosure, vented to the outdoors 
with a positive ventilator, such as a fan, is desirable. 
Electric Chlorination. Disinfection by means of electric chlori- 
nation is acceptable, provided the equipment has sufficient capacity 
to furnish the maximum demand necessary for the particular pool 
capacity. With this method an “alkalinity feeder” is often unneces- 
sary, because in the production of chlorine by electrolysis an alkaline 
solution is formed which helps maintain sufficient alkalinity. 
Off-Season Protection. In the case of outdoor pools, off-season 
protection, which is required during the major portion of the year, 
is important. In cold winter climates, protection of the pool structures 43 
against damage by ice should be considered. All pipe lines 
should pitch to low points and be provided with drain-cleanout 
plugs. Equipment such as motors, which might be damaged if ex- 
posed to possible flooding by high water or failure of sump pump, 
should be removed or elevated to a point where protection will be 
afforded. 
Equipment Room. If the equipment provided for maintaining 
the proper water condition in a swimming pool is not accessible or 
convenient, the operation will suffer. The practice of installing the 
equipment under the walk at the deep end of the pool should be per- 
mitted only when the elevation is such that proper protection can 
be made against flooding, and proper drainage, light, ventilation, 
etc., can be provided. 
Provision should be made to convey oil drippings from the pump 
to a drain. If gravity drainage is not possible and the equipment 
area drains to a sump, provision should be made for the off-season 
months (if an outdoor pool). Heat will be necessary in a majority 
of such installations to prevent freezing. 
Easy access, preferably not through the pool area, with heavy 
supplies such as barrels of alum, chlorine cylinders, etc., should be 
provided and storage space for them included. 
Provision should be made for hoisting motors in large installa- 
tions. A nonclogging type of pump will be required on the sump. 
Equipment, including motors, which might become damaged by im- 
mersion in water due to the failure of the pump, should be removed 
or elevated to a point where it will not be damaged during the 
off-season. Ventilation and sufficient air movement will be required 
to prevent condensation of moisture on filters, pipes, etc., and con- 
sequent damage. 
BATHER-PREPARATION FACILITIES 
Location. The location and layout of dressing-room facilities 
should be such as to enforce the routing of all persons who use the 
pool, through these various facilities in a direct manner and without 
cross-traffic, in the following order: Locker rooms (if provided), 
toilets (inside dry), toilets (inside wet), showers, footbaths (if pro- 
vided), and entrance to pool area. 
Showers. Devices are available which will turn otf a shower 
after allowing it to run for a timed interval. This allows the bather 
the use of both hands while showering. 
Foot-Controlled Showers. Methods have been designed where- 
by shower control is effected by the use of the feet, similar to those 
methods used by doctors and dentists on lavatories. 
Photoelectric Control of Straddle Showers. The “electric 
eye” has been used with some success to turn on the entrance 
shower. A Bidet or upward-flow spray beneath each shower to permit 
washing between the legs is desirable. 
The piping of each shower bath should be carefully designed 
for ease of operation and prevention of leakage, and should be fitted 
with a tight check valve in the cold-water pipe near the shower head. 
Controlled Baffle Gate. Personnel may be kept to the minimum 
and effective control still maintained in a pool and its facilities by 
the use of “controlled” baffle gates. Details will lie given to those 
interested. 
Dressing-Room Furniture. All furniture used in dressing rooms 
should be of simple character and of easily washable material. 
Lockers, where provided, should be of vermin-proof construction 
with tight joints. All lockers should be properly ventilated. 
Ramps. Transition from one level to another in the “bath- 
house” should be made with ramps and not with steps or stairs. 
Footbaths. In onr opinion, the primary function of footbaths 
is to prevent persons in street shoes from entering the pool area and 
to rinse excess dirt from the feet. Since improper maintenance of 
footbaths may aid in the spread of foot infections, it is felt that 
such should be forestalled by providing a suitable design such as a 
“flowing-through channel” or a conventional type in which the 
water is continuously added and withdrawn. Various shower or 
spray arrangements to wet the bathers as they pass to the pool area 
have been used. Some of these installations are automatically con- 
trolled by an “electric eye” to conserve water. 
All water inlets to the footbaths must terminate at least 6 inches 
above the maximum possible water level in the footbath. 
Team Rooms. In indoor pools which have considerable com- 
petition to which spectators are admitted, one of the problems has 
been to keep the spectators comfortably cool and the competitors 
sufficiently warm. This can be accomplished by including “team 
rooms” at the side or end of the pool where a proper temperature 
for the competitors can be maintained and their view of the events 
made possible by the use of glass partitions and doors. 
MISCELLANEOUS 
Drinking- Fountains. Drinking fountains should be provided 
in the pool area, in the dressing rooms, and for the spectators. Any 
fountains that are provided must meet the following design features: 
1. The fountain shall be constructed of impervious material 
such as vitreous china, porcelain, enameled cast iron, other metals, 
or stoneware. 45 
2. The jet of the fountain shall issue from a nozzle of non- 
oxidizing, impervious material set at an angle from the vertical. 
The nozzle and every other opening in the water pipe or conductor 
leading to the nozzle shall be above the edge of the bowl so that 
such nozzle or opening will not be flooded in case a drain from the 
bowl of the fountain becomes clogged. 
3. The end of the nozzle shall be protected by nonoxidizing 
guards to prevent persons using the fountain from coming into con- 
tact with the nozzle. The guard shall be designed so that the lips, 
when drinking, will not touch the guard. 
4. The inclined jet of water issuing from the nozzle shall not 
touch the guard. (This will prevent spattering.) 
5. The bowl of the fountain shall be so designed and propor- 
tioned as to be free from corners which would be difficult to clean 
or which would collect dirt. 
6. The bowl shall be so proportioned as to prevent unnecessary 
splashing at a point where the jet falls into the bowl. 
7. The drain from the fountain shall not have a direct physical 
connection to a waste pipe unless the drain is trapped. 
8. The water-supply pipe shall be provided with an adjust- 
able valve fitted with a loose key or an automatic valve permitting 
the regulation of the rate-of-flow of water to the fountain, so that 
the valve manipulated by the users of the fountain will merely turn 
the water on or off. 
9. The height of the fountain at the drinking level shall be 
such as to be convenient to persons utilizing the fountain. The pro- 
vision of several steps will permit children of various ages to drink 
comfortably. 
10. The waste opening and pipe shall be of sufficient size to 
carry off the water promptly. The opening shall be provided with 
a strainer. 
The fountain should be recessed or located so as to prevent 
accidents. 
Separate Spectator Provision. Separate provision shall be 
made for spectators outside the pool area, and the drainage from the 
spectator area shall in no case be allowed to drain upon the area 
used exclusively by bathers. 
The spectator area should be at a point of vantage. When a 
balcony, it should not overhang the pool area. Gallery floor should 
slope to a drain. Seats should be so located that vision is not inter- 
fered with by pillars, railings, etc., and constructed of nonabsorbent 
material to permit washing. Spectators should preferably be located 
at right angles to the diving boards with their backs to the sun. A 
curb or other provision should be used to prevent litter and dirt 
from being kicked or scuffed by spectators into the pool or pool 
area. Shade, and protection from rain in outdoor pools should be 
provided. 
Fancy diving is much more attractive to the spectator when 
viewed from right angles to the diving. Spectators should be lo- 46 
cated as close as practical to the diving area because the relation- 
ship of performer and spectator is much more satisfactory at close 
range. 
Spectators’ Toilets. Toilets should be provided for spectators 
to prevent their entering the dressing area provided for bathers, 
with accompanying lack of control and the introduction of exces- 
sive dirt. 
At pools not larger than 50'x 100' in area, with a permissible 
bathing load not to exceed 700 persons, there should be provided 
for the spectators, 3 closets, 4 urinals, and 2 lavatories for men, and 
4 closets and 2 lavatories for women. Larger pools should provide 
5 closets, 8 urinals, and 4 lavatories for men, and 6 closets and 4 
lavatories for women. The toilet rooms should meet the require- 
ments as set forth in the minimum requirements. 
Parking Facilities. Adequate provision should be made to 
handle the problem of parking. The parking area should be as con- 
veniently located as possible, should be properly lighted, provided 
with adequate drainage and, of course, surfaced in such a way that 
it can be used in rainy weather when necessary. When the topog- 
raphy is such that the parking area overlooks the pool area, it will 
meet with popular approval of the older persons who do not swim, 
but who enjoy watching their friends and families disport them- 
selves in the pool. 
Salt-Water Pools. Salt water, botli natural from deep wells, 
and also from an artificial source, has been used with success in 
pools. Provision must be made, however, to prevent corrosion 
when this is done. 
Pools for Specialized Requirements. In the design of pools 
such as those intended primarily for crippled children, other thera- 
peutic purposes, etc., consideration should be given in the design to 
the specialized requirements of such installations. This Department 
will gladly go into the details believed desirable in such pools, upon 
application from those authorities contemplating their installation. 
Laundry. All pools should include in their design provisions 
for the proper laundry equipment for handling suits and towels. 
Equipment for proper washing, rinsing, drying, and storing should 
be included, and this equipment should be so located that it is 
accessible, properly lighted, and ventilated. The same standards of 
cleanliness, disinfection, etc., should be required in the handling of 
suits and towels as are required at public laundries. The necessary 
steam or hot water required for the proper operation of the laundry 
must be available. 
Patents. Some items in connection with pools, such as special 
shapes, contours, inlet arrangements, etc., have been patented. 
However, most basic items have been in common use for many 
years and may be used without question of infringement. It is 
suggested that when such questions arise the services of a qualified 
patent attorney be retained. 47 
WADING POOLS 
Location. A wading pool should be located where the afternoon 
snn will fall on the major portion of the area. While some shade is 
desirable, too much shade will result in an unpopular pool. 
Sizes. Wading pools should not be too large. A smaller, better- 
designed, and better-operated layout, even if used in relays, is to be 
preferred. 
Overflow. A wide overflow edge (2 feet to 3 feet) with a non- 
slip finish (concrete) is recommended, with a slightly depressed 
trough surrounding the entire area. 
Spray Pools. Recently there has been a trend to convert exist- 
ing wading pools, which lack the proper design to make it possible 
for them to be maintained in a sanitary condition, into spray pools. A 
spray pool uses the former wading pool as a basin, the drains being 
open at all times. Considerable variation can be made in the spray 
mechanisms. A spray pool serves approximately the same purpose 
as a wading pool with almost none of the public-health hazards to be 
found in the typical wading pool. In a spray pool the individual 
does not expose himself to water which has already been exposed to 
other persons’ body wastes. Without doubt, many existing wading 
pools could be changed to spray pools with very definite advantage. 
Drinking Fountain. A sanitary drinking fountain should be 
provided at one side or end of the area with a raised step to enable 
the very small children, as well as the older ones, to drink without 
assistance. 
The fountain must meet the requirements given previously in 
this bulletin. 48 
INDEX 
Acoustics, 33 
Adjustable courses, 29 
fulcrurns, 34 
Aeration, inlet, 36 
Air releases, 17 
Alkalinity 
electric chlorination, 42 
testing outfit, 19 
Ammonia, 42 
(See also Chloramine.) 
Area, swimming, 27, 28 
Automatic showers, 43, 44 
Back-siphonage, 17, 18, 22, 24, 44 
(See also Cross-connections.) 
Backwash, 14, 15, 17, 37, 38, 39 
connect to sewer, 18 
Bacteriological standards, 8, 23, 24 
Baffle gates, 44 
Balancing tanks, 18, 34, 39, 41 
Barriers, 13, 24, 30, 36 
Beaches, 13 
Blow-off, 37 
Booths, dressing and shower, 20, 21, 22 
Bottom 
finish, 9, 23 
hopper, 28, 30 
ledges, 31 
slopes, 9, 12, 23, 24, 30, 31 
Buoys, 36 
Bushhammering, 32 
Capacity 
chlorine equipment, 16, 42 
drains, 24 
filter, 16, 39 
piping system, 18, 24 
Chemical-feeding equipment, 38 
Chloramines, 42 
Chlorine 
ammonia, 42 
capacity of equipment, 16, 42 
dissipation of, 16, 36, 42 
disinfection, 16, 24 
electric process, 42 
equipment location, 42 
point of application, 16 
testing outfit, 19 
Civil Administrative Code, 4 
Cleanouts, 18, 43 
Clarity, 8, 36 
Closed system, 41 
Coaching windows, under water, 32 
Coagulant 
equipment, 14, 16, 38, 41 
point of application, 16, 38, 41 
Competitive 
courses, 27, 29 
lane markers, 29, 30 
pools, 27, 29 
Concrete 
color, 9, 31, 33 
diving stand, 34 
finish, 9, 23, 24, 31 
nonslip, 9, 23, 24, 31 
paint, 31, 32 
Contours, 46 
Courses 
adjustable, 29 
competitive, 27, 29, 30 
Cross-connections, 10, 13, 17, 24, 39, 41, 44 
* (See also liSck-siphonage.) 
Curbs, 10, 33, 45 *. 
Definitions 
spray pool, 23 
swimming pool, 4 
wading pool, 23 
Dimensions 
overflow gutter, 33 
pool, 26, 27, 28, 29, 30, 47 
Depths 
diving, 28 
marking, 29, 30, 36 
wading pools, 23 
Disinfection, 14, 16, 24, 36 
(See also Chlorine.) 
foot baths, 44 
methods of, 42 
Diving 
adjustable fulcrum boards, 34 
board location, 34 
concrete stand, 34 
depths, 28 
equipment, 34 
masks, 37 
Double-level pools, 14 
Drainage 
dressing room, 20 
equipment room, 19, 43 
off-season, 18, 43 
overflow gutter, 12, 24, 34, 41 
piping system, 42 
shower room, 21 
spectator area, 10, 45 
subsurface, 29 
toilet rooms, 22 
walk areas, 9, 24, 33, 45 
Drains 
(See also Main drain.) 
connection to sewer, 13, 18, 19, 23, 24, 26 
29, 45 
overflow gutter, 34, 41 
spray pool, 23 
wading pool, 24 
Dressing rooms, 20 
floors, 20, 31 
furniture, 44 
location and layout, 43 
Drinking water, 8, 23, 24 
fountains, 44, 47 
Effective size, sand, 17 
Electric chlorination, 42 
Equipment room, 19, 43 
Fences, 24, 30, 36 
Filtration 
access to, 19, 43 
backwash, 17, 18 
capacities, 16, 38 
equipment, 14, 16, 38 
filter media, 17, 39 
requirements, 14, 16, 18 
surface wash, 39 
underdrains, 17 
Finish 
floors, 20, 21, 22, 31, 32 
overflow gutters, 13, 24 
pool, 9, 23, 24, 31 
walks, 10, 24, 31 
Floats, 34 
Floors 
(See also Finish, floors.) 
pitch, 19, 21, 22, 45 
Foot baths, 43, 44 49 
Fountains 
drinking water, 44, 47 
pool inlet, 36, 42 
Gauges 
loss-of-head, 17 
piping system, 37 
pressure, 17, 37 
rate-of-flow, 17 
Grass areas, 13 
Gratings, 11, 34, 37 
Gravel, filter, 17 
Gravity filters, 17, 38 
Hair strainer, 14, 15, 37 
Heat exchanger, 38, 42 
Heating, 33, 37, 43 
(See also Temperature, control.) 
High diving (See Diving.) 
Hopper bottom, 28, 30 
Hose connections, 12, 20, 22, 23, 24, 33 
Inlets 
location, 10, 24, 36 
multijet, 36 
nozzle, 36 
testing discharge of, 38 
velocity, 36 
wading pool, 24 
Inspection 
for opening pool, 7 
Ladders, 13, 31 
Lanes 
competitive, 29, 30 
surface, 30 
Laundry, 46 
Lavatories, 22, 46 
Law, swimming pool, 4 
Ledges, 30 
Lighting, 11, 20, 22, 32, 43 
Lint catcher, 14, 15, 37 
Location 
dressing rooms, 20, 43 
equipment, 34, 36, 37, 38, 41, 42, 43, 44 
foot baths, 43 
inlets, 10, 24, 36 
pools, 14. 23, 26, 47 
showers, 21, 43 
spectator area, 45 
toilets, 22, 46 
Loss-of-head gauges, 17 
Main drain, 18, 23, 24, 30 
Markings 
depth, 36 
main drain, 30, 37 
pool, 29, 30 
Material 
construction, 9, 20, 21, 22, 23, 24, 31, 34 
Mats, floor, 32 
Meters, water, 37, 41 
Multijet inlets, 36 
Multiple pools, 27 
Nonslip (See Finish.) 
Nozzles, inlet, 36 
Obstructions, 18, 23, 30, 31, 33, 45 
Off-center hopper, 28 
Off-season drains, 18, 43 
Outlets, 11, 36 
Oveiflow gutters, 12, 33 
balance tanks, 34, 39, 41 
double-level pools, 14 
loss of water through, 27, 39 
wading pools, 24, 47 
Paint 
for lane markers, 30 
nonslip, 32 
pool, 31 
Parking facilities, 46 
Patents, 46 
Penalties, 5 
Permit, 4, 7 
pH, testing outfit, 19 
Piers, 34 
Plans and specifications, 6 
Pool 
authority for control, 4 
laundry, 46 
linings, 31 
location of, 14, 23, 26, 47 
size of, 26, 27, 28, 29, 47 
specialized, 46 
Portable pools, 32 
Pressure filters (See Filtration.) 
gauges, 17 
Prosecution, 5 
Protection 
off-season drainage, 18, 43 
winter, 32, 42, 43 
Pumping equipment, 14, 15, 37, 38, 43 
Rafts, 34 
Ramps, 31, 44 
Rate-of-tlow gauges, 17 
Recirculation system, 14 
access to, 19, 37 
equipment, 15 
piping, 16, 18, 37, 38, 41, 43 
test of, 37, 38 
Salt water, 46 
Sand areas, 13 
filter, 16, 39 
Sewers, 
connection to, 13, 18, 19, 21, 23, 24, 26, 
29, 45 
Shower facilities, 20, 43 
Sight glasses, 17 
Size (See Pool.) 
Soap dispensers. 21 
Spectators 
provisions, 26, 45 
toilets, 46 
Spiays, inlet, 36 
Spray pools, 23, 47 
Spring boards (See Diving.) 
Steps and stairs, 13, 23, 31, 44 
Sterilization (See Disinfection.) 
Subsurface drainage, 29 
Suction cleaner, 13, 15, 37 
diving mask, 37 
Surface lanes, 30 
Surge tank, 18, 34, 38, 39, 41 
Siphon breaker, 18 
Team rooms, 44 
Temperature 
closed system, 41 
control, 36, 38, 42, 44 
shower water, 21 
Thermometers, 38 
Testing outfit 
chlorine, 19 
pH, 19 
Toilets, 21, 24, 43, 46 
Treatment sump, 38 
Tunnel, access, 32, 37 
Turnover, rate of, 14, 15, 16 
Twin pools, 29 
Underdrains, 17 
Under-water 
coaching windows, 32 
diving masks, 37 
entrance, 32 
lights, 32 
Uniformity coefficient, 17 
Urinals, 22 
Ventilation, 20, 22, 43, 4y 50 
Wading pools, 23, 24, 47 
Walk 
area, 9 
colored, 33 
curbs, 33 
drainage, 33 
finish, 23, 24, 31 
slopes, 10, 24 
Wash rates (See Filtration.) 
Water 
cross-connections, 17 
depth of, 27, 28 
disinfection of, 16, 24, 36, 42 
heater, 37 
make-up facilities, 17, 41 
meters, 37, 41 
supply, 8, 23, 24, 41, 46 
treatment, 41 
Winter protection, 32 (55861)