(a) Swimming pools, when in use, shall be continuously disinfected with a chemical which imparts an easily measured, free available residual effect. When chlorine is used, a free chlorine residual of at least 0.4 p.p.m. shall be maintained throughout the pool whenever it is open or in use. If other halogens are used, residuals of equivalent disinfecting strength shall be maintained. A testing kit for measuring the concentration of the disinfectant shall be provided at each swimming pool.
(b) The swimming pool water shall be maintained in an alkaline condition as indicated by a pH or not less than 7.2 and not more than 8.2. A pH testing kit shall be provided at each swimming pool.
(c) The water shall have sufficient clarity at all times so that a black disc, six inches in diameter, is readily visible when placed on a light field at the deepest point of the swimming pool.
(d) No more than fifteen percent (15%) of the samples covering any considerable period of time shall either:
(1) Contain more than 200 bacteria per milliliter, as determined by the standard (thirty-five degree Centigrade) agar plate count; or
(2) Show a positive test (a confirmed test) for coliform organisms in any of the five ten-milliliter portions of a sample or more than 1.0 coliform organisms per fifty milliliters when the membrane filter test is used. The Health Department shall arrange for the collection and examination of samples on a routine basis when the swimming pool is in active use.
(Res. 23-76. Passed 3-2-76.)