Development and application of equilibrium partitioning sediment guidelines in the assessment of sediment PAH contamination

The U.S. Environmental Protection Agency used insights and methods from its water quality criteria program to develop ESGs. The discovery that freely-dissolved contaminants were the toxic form led to equilibrium partitioning being chosen to model the distribution of contaminants in sediments. Empirical and mechanistic models encompassing narcosis theory, critical body burdens, and chemical additivity became the framework of a defensible ESG for PAH mixtures. An assessment of Sinclair Inlet, WA sediment is made utilizing bulk sediment and interstitial water concentrations.