ENV-01-07 A Comparative Analysis of Technical Approaches for Mercury TMDL Development

Description:

Many state environmental regulatory agencies and the U.S. Environmental Protection Agency (EPA) Regions are actively developing total maximum daily loads (TMDLs) for impaired water bodies within their respective jurisdictions. A heightened priority has been placed on development of TMDLs for toxic pollutants. A widespread toxic pollutant of concern requiring TMDL development is mercury, whether evaluated as total mercury, dissolved ionic mercury, or methylmercury. This paper presents a comparative analysis of different technical approaches being used within EPA Regions 4 and 6, in the States of Georgia and Louisiana, respectively. The technical approaches, assumptions, and calculations/modeling for mercury TMDL development are discussed.