ARSD 74:51:01:24. Modification of criteria for specific sites

Criteria established in §§ 74:51:01:31, 74:51:01:32, and 74:51:01:44 through 74:51:01:54, inclusive, and in § 74:51:01:56 may be modified to reflect local conditions through determination of site-specific criteria for toxic pollutants in a segment. Modification of criteria must incorporate analyses of physical, chemical, and biological conditions of the receiving waters to assure maintenance of the assigned beneficial use. Actual effluents or effluent simulations may be evaluated in a toxicity testing program conducted under environmental conditions similar to the discharge site in the receiving waters. Analytical procedures, calculation procedures used to measure or demonstrate the toxicological significance of a pollutant, and numerical criteria may be modified by the board after opportunity for public review and comment. All data necessary to defend the proposed modification of criteria are the responsibility of the person or entity requesting the modification. Methods used to develop site-specific criteria must be approved by the secretary and shall include methods to evaluate effects of bioaccumulative pollutants where appropriate. The Water Quality Standards Handbook, 2017, may be used as guidance in developing methods.