(1) Inlets. Inlets allow fresh or treated water to enter the pool. Inlets
should be located to produce uniform water circulation and to maintain a uniform
disinfectant residual throughout the pool. See figure 1-1 for inlet location.
(a) Circulation system inlets should be flush with pool walls pool. Each
inlet should either be designed as an adjustable opening or be provided with an
individual valve that adjusts water volume to obtain the best circulation.
(b) Where the incoming water (influent) is from a potable water
system, cross-connections should be eliminated. This is done by pumping makeup
water from a pump suction well or by admitting water to the pool with an air gap
(c) Inlets should be placed at approximately 20-foot intervals
around the pool. Each inlet should either be designed as an adjustable opening or
be provided with an individual valve that adjusts water volume to obtain the best
(2) Outlets. These are provided at the deepest point to permit the pool to be
completely and easily emptied in about four hours. See figure 1-1 for outlet location.
(a) Openings should be covered by a grating which bathers cannot
remove easily. The minimum width of grate openings should be one-half inch; they
should be designed to prevent swimmers' hands and feet from being caught. Openings
of the gratings in the floor of the pool should be at least four times the area of the
discharge pipe. Otherwise, gratings must have sufficient area so that the maximum
velocity of the water passing through the grating will not exceed 1 feet per second
(b) Multiple outlets, spaced not more than 30 feet apart or more than
15 feet from sidewalls are authorized for pools with deep water.
(c) Direct connections to sewers should be avoided. All drains from
the pool to sewers should be constructed with an air-break to prevent sewage from
backing up into the pool.
e. Overflow Gutters and Skimmers. These are designed to remove portions
of the circulating water and to return the water to a filter unit.
(1) Overflow gutters. Overflow gutters should extend completely around the
pool and serve as a handhold except at steps or recessed ladders in the shallow area.
Gutters should be able to continuously remove the recirculating water and return it to
the filter. Figures 1-1 and 1-2 show the location and appearance of gutters.