5.
Physical Procedures

The physical factors in the sanitation of bathing vlaces are their loca
tion, design,and construction. To be successful financially, recreationally,
and from the standpoint of health, bathing beaches and swimming pools must be
readily accessible to the public, as far removed as practical from sources of
pollution, and in attractive surroundings:

Under design and construction ve include &11 the engineering and
erchitectural features which reduce contamination, prevent drorning, safeguard
against injury, promote dleanliness, and provide for the comfort of the bathers.
The sloping of the floors, runvays, end sidewalks, the provision of scum gutters,
the location of inlets and outlets, the arrangement of the shovers and the
placing of footbaths are structural considerations which may ¢ontribute quite
materially to the sanitation of both indoor and outdoor pools.

The arrangement of dressing rooms; the adequacy of toilets, lavatories,
and showers; suitable temperatures of both the room and the water: and good
ventilation are conducive to sanitation through the cleanliness’ and comfort
of the bathers. Recirculation systems and their accessories and filtration
are all essential physical or engineering end architectural factors in swimming
pool sanitation,

Sefety

The depth of the vater, the height of diving boards, the sloping of the
bottom of the pool, its markings, the number of swimmers permitted in its verious
zones, and lighting have a direct bearing upon the occurrence of accidents.

The reduction of turbidity by stornge, coagulation, sedimentation, filtration,
dilution, or other processes of clarification is also a measure of safety. The
provision of a special closet for chlorine containers, the avoidance of cross
connections, and the insurance of good acoustics are likewise important safe-
guards.

Chemical Considerations

The chemistry of swimming pool vater may affect its sanitation, safety,
cost of operation and popularity. When large quantities of calcium bicerbonates
are present in the water it may become difficult to keen it clear. The ex-
cessive use of alum may cause turbidity by the substance passing through the
filters in solution and producing a floc in the pool. The use of chloride of
lime may also increase the eloudd sees of the water until the pool is unsafe, The
continuous use of alum, the presence of calcium sulphate, and calcium hypochloride
or of chemicals added to influence the reaction of the vater may lead to the
formation of deposits in the circulating equipment and to consequent turbidity.

Hardness in vater, due especially to the selts of calcium end magnesium,
adds to the exoense of operation of bathing places by increasing the cost of
soap, liming of heaters, and clogging of strainers. Cne grein of calcium
carbonate will use up eight grains of soap before a lather can be provided, Thus,
hard water causes an enormous vaste of soap. The scale of heaters is usually
a deposition of the sulphates and carbonates of calcium and magnesium. These
substances damage valves end othervise hasten the depreciation of plumbing.

‘~The color of swimming pool vater may be of both organic and inorganic
origin. In some instances in outdoor ponds it may be m extraction from such
vegetative matters as leaves, bark, or roots, or its source may be algae.
Manganese and especially iron are inorganic substances which give the sides,
bottoms, end fixtures of pools a more or less characteristic color. The greeness