15A NCAC 18C .2002. DISINFECTION

The provisions of 40 C.F.R. 141.72 are hereby adopted by reference in accordance with G.S. 150B-21.6 including subsequent amendments and editions.  Copies are available for public inspection as set forth in Rule .0102 of this Subchapter.  These provisions are adopted with the following exceptions:

(1)           Water entering the distribution system.  In 40 C.F.R. 141.72 (a)(2), (a)(3), and (b)(2), "0.2 mg/l" of  residual disinfectant concentration shall be replaced with "0.2 mg/l measured as free chlorine when chlorine is the singular applied disinfectant and 1.0 mg/l measured as total chlorine when ammonia and chlorine are applied disinfectants."

(2)           Water in the distribution system at coliform sampling sites.  In 40 C.F.R. 141.72(a)(4) and (b)(3), "undetectable" shall be replaced with "less than 0.2 mg/1 measured as free chlorine when chlorine is the singular applied disinfectant and less than 1.0 mg/l measured as total chlorine when ammonia and chlorine are applied disinfectants."

(3)           Water in the distribution system at maximum residence time sites.  For samples collected at maximum residence time sites or at other locations with high water age as required by Rule .1302(a)(2) of this Subchapter, residual disinfectant concentrations shall be at detectable levels as set forth and calculated in 40 C.F.R. 141.72(a)(4) and (b)(3).

 

History Note:        Authority G.S. 130A‑315; P.L. 93‑523; 40 C.F.R. 141.72;

Eff. January 1, 1991;

Amended Eff. April 1, 2014; October 1, 2009.