Section 58.01.02.284 - SOUTH FORK COEUR D'ALENE SUBBASIN, SUBSECTION 110.09, HUC 17010302, AQUATIC LIFE CRITERIA FOR CADMIUM, LEAD AND ZINC
The following criteria are to be met dependent upon the hardness, expressed as mg/l of calcium carbonate, of the water. Criterion maximum concentrations (CMC), one (1) hour average concentrations, and criterion continuous concentrations (CCC), four (4) day average concentrations, of the dissolved metals (in µg/l) are not to exceed, more than once every three (3) years, the values calculated using the following equations:
01.Cadmium. a. CMC = 0.973 x e [(1.0166 x ln(hardness)) - 3.924]b. CCC = [1.101672 - (In (hardness) x 0.041838] x e [(0.7852 x ln(hardness)) - 3.490]02.Lead. a. CMC = e [(0.9402 x ln(hardness)) + 1.1834]b. CCC = e [(0.9402 x ln(hardness)) - 0.9875]03.Zinc. a. CMC = e [(0.6624 x ln(hardness)) + 2.2235]b. CCC = e [(0.6624 x ln(hardness)) + 2.2235]04.Application.a. The maximum hardness allowed for use in the equations in Section 284 shall not be greater than four hundred (400) mg/l even if the actual ambient hardness is greater than four hundred (400) mg/l.b. The criteria described in Section 284 apply to all surface waters within the subbasin, except for natural lakes, for which the statewide criteria given in Section 210 apply.