Abstract |
The Clean Water Act requires that ambient water quality criteria (WQC) published by EPA reflect the latest scientific knowledge concerning the physical fate (e.g., concentration and dispersal) of pollutants, the effects of pollutants on ecological and human health and welfare, and the effect of pollutants on biological community diversity, productivity, and stability. Current ambient WQC levels for trace metals require measurement capabilities at levels as much as 280 times lower than those achievable using existing EPA methods and required to support technology-based permits. This document addresses the difficulties associated with measuring trace metals at ambient WQC levels and outlines a plan and schedule for achieving such measurements. |