Louisiana Administrative Code
Title 51 - PUBLIC HEALTH-SANITARY CODE
Part XII - Water Supplies
Chapter 3 - Water Quality Standards
Section XII-355 - Mandatory Disinfection [formerly paragraph 12:021-1]

Universal Citation: LA Admin Code XII-355

Current through Register Vol. 50, No. 12, December 20, 2024

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.

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

Disclaimer: These regulations may not be the most recent version. Louisiana may have more current or accurate information. We make no warranties or guarantees about the accuracy, completeness, or adequacy of the information contained on this site or the information linked to on the state site. Please check official sources.
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