La. Admin. Code tit. 51 § XII-355

Current through Register Vol. 50, No. 11, November 20, 2024

Section XII-355 - Mandatory Disinfection [formerly paragraph 12:021-1]

A. Routine, continuous disinfection is required of all public water systems.

1. Where a continuous chloramination (i.e., chlorine with ammonia addition) method is used, water being delivered to the distribution system shall contain a minimum concentration of 0.5 mg/l of chloramine residual (measured as total chlorine).

2. Where a continuous free chlorination method is used, water being delivered to the distribution system shall contain a minimum concentration of free chlorine residual in accordance with the following table.

Table 355.A.2
pH Value	Free Chlorine Residual
up to 7.0	0.5 mg/l
7.0 to 8.0	0.6 mg/l
8.0 to 9.0	0.8 mg/l
over 9.0	1.0 mg/l

a. Table 355.A.2 does not apply to systems using chloramines.

b. pH values shall be measured in accordance with the methods set forth in §1105. D of this Part.

B. All new groundwater systems installed after July 1, 1996 shall provide at least 30 minutes contact time prior to the first customer. It is recommended that all existing systems provide the 30 minutes contact time prior to the first customer. Additions to or extensions of existing systems are exempt from the 30 minutes contact time.

C. Public water systems which use surface water or ground water under the direct influence of surface water shall meet the requirements of applicable Sections of the surface water Treatment rule (LAC 51:XII.Chapter 11) as it pertains to CT and Giardia, Cryptosporidium, and virus removal/ inactivation/disinfection requirements.

D. The effective date for mandatory disinfection for all public water systems serving a population of greater than 500 shall be July 1, 1995.

E. The effective date of mandatory disinfection for all public water systems serving a population of 500 or less shall be July 1, 1996.

La. Admin. Code tit. 51, § XII-355

Promulgated by the Department of Health and Hospitals, Office of Public Health, LR 28:1326 (June 2002), amended LR 28:2514 (December 2002), LR 35:1240 (July 2009), LR 38:2376 (September 2012), Amended LR 42408 (3/1/2016), Amended by the Department of Health, Office of Public Health, LR 441252 (7/1/2018).

AUTHORITY NOTE: Promulgated in accordance with R.S. 40:4(A)(8)(13) and R.S. 40:5(2)(3)(5)(6)(17)(20).