(a) Water-testing kits. Approved water-testing kits shall be provided at each public and semi-public pool for determining the pH level, the free available chlorine, and the total available chlorine. The test kit shall use the DPD (diethyl-phenylene diamine) method for testing free available chlorine. If a pool is stabilized by the use of cyanuric acid, an approved test kit for measuring cyanuric acid shall be provided.
(b) Turbidity. The turbidity of the water in a public or semi-public pool may not visually obscure the view of the main drain or the bottom of the pool.
(c) Free chlorine residual. The free chlorine residual shall be maintained between 1.5 and 5.0 parts per million in public or semi-public pools, between 3.0 and 5.0 parts per million in wading and therapy pools, and between 4.0 and 5.0 parts per million in spas.
(d) Combined chlorine. The maximum amount of combined chlorine shall be 0.2 parts per million for public and semi-public pools and spas.
(e) Disinfectants other than chlorine. Disinfectants other than chlorine may be utilized in a pool when approved by the Health Officer and must be maintained in the concentrations specified in State regulations as set forth under COMAR, 10.17.01.
(f) Cyanuric acid. In pools stabilized by use of cyanuric acid, the level of cyanuric acid must be maintained between 30 and 100 parts per million.
(g) pH level. The pH level of public and semi-public pools shall be maintained between 7.2 and 7.8.
(h) Filtered water. The delivery of filtered water to a public or semi-public pool may not be interrupted for more than one hour in any one continuous 24-hour period, excluding time required for backwashing operation, cleaning hair and lint traps, and cleaning of the chlorinator.
(i) Disinfectants. The owner shall ensure that a disinfectant or combination of disinfectants is added to the water automatically through an approved chemical feeder to maintain chlorine or disinfectant residuals. The automatic disinfectant feeder may not be inoperative in excess of 24 consecutive hours. Chemicals may not be added during any inoperative period except in the manner prescribed by the Health Officer.
(1985 Code, Art. 16, § 16-305) (Bill No. 89-97)