Ala. Admin. Code r. 335-7-5-.17

Current through Register Vol. 42, No. 12, September 30, 2024

Section 335-7-5-.17 - Disinfection Requirements

Disinfection of the water shall be accomplished using a chemical or treatment technique accepted by the Department. Sufficient contact time to allow proper disinfection to take place must be provided as follows:

(a) A chlorine concentration time (CT) of at least 60 shall be provided when the average monthly turbidity is less than five NTU, and

1. The geologic conditions are such that contamination may occur, or

2. The average total coliform count of the raw water exceeds 20 per 100 milliliters but is less than 100 per 100 milliliters for an average of weekly samples for a minimum of four consecutive months, or

3. The average fecal coliform (or E. coli) count of the raw water exceeds five per 100 milliliters but is less than 20 per 100 milliliters for an average of weekly samples for a minimum of four consecutive months.

4. Should a disinfectant other than chlorine be used, an equivalent CT time will be provided by the Department.

(b) Water systems shall maintain an adequate level of disinfectant residual in the distribution system at all times. This residual shall be determined and recorded daily from an approved sampling site or other representative point in the system. For systems using chlorine as disinfectant, the residual shall be maintained at a level no less than 0.2 mg/L free chlorine. Should the residual at a sampling site fall below 0.2 mg/L and not be restored within four hours, a treatment technique violation has occurred requiring appropriate public notification within 14 days. Should the disinfectant residual not be restored within 24 hours, microbiological samples representative of the effected area shall be collected. Should these samples show system contamination, an acute violation has resulted, requiring appropriate notification.

Ala. Admin. Code r. 335-7-5-.17

May 23, 1977. Repealed and Readopted: January 4, 1989; October 31, 1990; effective December 5, 1990. (Rule was renumbered from .16 to .19.) Amended: Filed December 21, 1998; effective January 25, 1999. (Rule was renumbered from .19 to .25.) Amended: Filed May 2, 2000; effective June 6, 2000. Amended: Filed November 7, 2005; effective December 12, 2005. Amended: Filed August 21, 2012; effective September 25, 2012.

Rule 335-7-5-.25 was renumbered .17 as per certification filed November 7, 2005; effective December 12, 2005.

Authors: Joe Alan Power, Edgar K. Hughes

Statutory Authority:Code of Ala. 1975, 22-23-1 through 22-24-12.