ABSTRACT
Stormwater regulations require the development and implementation of a specific management plan for controlling contaminant release, as well as specific water quality monitoring which includes Whole Effluent Toxicity testing. The deficiency in hardness also reduces the capacity of the stormwater to buffer the aquatic toxicity of many cationic metals. Definitive acute toxicity tests used to evaluate the characterization treatments were conducted as described in Methods for Measuring the Acute Toxicity of Effluents to Freshwater and Marine Organisms. Metals toxicity is influenced by a number of chemical factors including calcium and magnesium salts, hardness, alkalinity, pH, and matrix ionic strength. The two classes of toxicants most commonly identified in stormwater are cationic metals such as, copper, lead, zinc, nickel, cadmium, chromium, and silver; and pesticides (primarily organophosphates). Surfactants, miscellaneous semipolar organic toxicants, and cyanide have also been identified in specific case studies, but are much less common.
