Ala. Admin. Code r. 335-7-10-.04

Current through Register Vol. 43, No. 1, October 31, 2024

Section 335-7-10-.04 - Disinfectant Residual Requirements

All public water systems required to provide disinfection shall maintain a residual level to provide protection of the water throughout the distribution system. These systems must meet the following requirements;

(a) Departmental approval is necessary for use of any disinfectant other than chlorination.

(b) Systems, with Department approval, may increase residual disinfectant levels in the distribution system of chlorine or chloramines (but not chlorine dioxide) to a level and for a time necessary to protect public health, to address specific microbiological contamination problems caused by circumstances such as, but not limited to, distribution line breaks, storm run-off events, source water contamination events, or cross-connection events.

(c) Systems must maintain a minimum disinfectant residual level established by the Department. The minimum disinfectant level in the distributions system shall be no less than 0.2mg/L for free chlorine or 0.5 mg/L for chloramines. Systems must also not exceed the maximum residual disinfection level at any time.

(d) Upon the determination that the disinfectant level in the service area distribution system falls below the established minimum or exceeds the maximum and is not corrected within four hours, a treatment technique violation has occurred requiring the following action:

1. The treatment process must be revised to correct the violation.

2. The Department must be notified by the end of the next business day.

3. The system must provide proper notification to customers affected in a newspaper of general circulation serving the area within 14 days of the occurrence or for NTNC systems, post notice in appropriate locations.

4. Should the disinfectant residual not be restored within 24 hours, microbiological samples must immediately be collected from representative locations within the area of insufficient disinfectant residual. Should these samples show system contamination an acute violation has resulted, requiring appropriate notification required under rule 335-7-2-.21.

(e) A maximum free residual of no more than 4.0 mg/L for chlorine or chloramines or 0.8 mg/L for chlorine dioxide shall be maintained at any point in the distribution system.

Ala. Admin. Code r. 335-7-10-.04

May 23, 1977. Repealed and readopted: January 4, 1989; October 31, 1990; effective December 5, 1990. Amended: Filed May 2, 2000; effective June 6, 2000. Amended: Filed November 7, 2005; effective December 12, 2005. Amended: Filed December 18, 2008; effective January 22, 2008. Amended: Filed April 21, 2009; effective May 26, 2009.

Authors: Joe Alan Power, Edgar K. Hughes, Dennis D. Harrison

Statutory Authority:Code of Ala. 1975, §§ 22-23-33, 22-23-49, 22-22A-5, 22-22A-6.