D.C. Mun. Regs. tit. 25, r. 25-C6416

Current through Register Vol. 71, No. 49, December 6, 2024
Rule 25-C6416 - WATER QUALITY - STANDARDS, CHEMICAL QUALITY*
6416.1

The Department may collect water samples and examine them as necessary to determine compliance with these regulations.

6416.2

Chemicals used in controlling the quality of the pool water shall be tested and approved using the National Sanitation Foundation (NSF-ANSI) Standard 60, 2005, which is incorporated by reference into these rules and shall be compatible with other accepted chemicals used in pools. The following parameters shall be adhered to for pool water treatment:

(a) Water pH - 7.2 to 7.8;
(b) Disinfection - Free chlorine residual shall be 1 milligram per liter (mg/L) to 10 mg/L, inclusive, in conventional swimming pools and 2 mg/L to 10 mg/L, inclusive, in all other type pools such as spa-type pools and interactive water fountains; bromine residual shall be 1.5 mg/L to 10 mg/L, inclusive, in conventional swimming pools and 3 mg/L to 10 mg/L, inclusive, in all other type pools. Except that, the following maximum disinfectant levels shall apply to indoor conventional swimming pools: 5 mg/L free chlorine or 6 mg/L bromine;
(c) When oxidation - reduction potential controllers are required, the water potential shall be kept between 700 and 850 millivolts. Use of these units does not negate the manual daily testing requirement of section 6422;
(d) Cyanuric acid - 40 mg/L maximum in pools and in spa pools; and
(e) Quaternary ammonium - 5 mg/L maximum.
6416.3

Irrigation water that wets the deck area of a pool and the water in the pool shall be potable water. Non-potable irrigation water shall not be applied within ten (10) feet of the wet deck area.

6416.4

Manual addition of chemicals will be allowed under special conditions and requires the pool to be closed prior to addition and for at least one (1) hour after addition, or a longer period as necessary, for sufficient and safe distribution of the chemical. After treatment for breakpoint chlorination and algae prevention, use of the pool can be resumed when the free chlorine levels drop to 10 mg/L.

D.C. Mun. Regs. tit. 25, r. 25-C6416

Final Rulemaking published at 55 DCR 012845 (December 26, 2008)