Superfund Research Program
Water-Sediment Model and Criteria for Arsenic and Chrome
Project Leader: Dominic M. Di Toro (University of Delaware)
Grant Number: P42ES010344
Funding Period: 2000 - 2006
Project Summary (2000-2006)
The goal of this project is to develop the chemical basis for establishing sediment quality criteria for arsenic and chromium and to construct coupled water column-sediment fate and transport models. Researchers are using the Equilibrium Partitioning (EqP) model, that is currently being used by EPA, in order to generate these criteria. This approach requires determining the solid phase or phases that regulate pore water concentrations, developing quantitative relationships between solid phase and pore water concentrations, and determining the potential for remobilization (and future exposure) of sediment bound metal. Future exposure concentrations in the sediments and overlying water are being estimated using mathematical models that describe the combined effects of transport and chemical/biochemical reactions. For water column animals and their human consumers, the extent to which metals are released from sediments to the overlaying water, and the extent to which the reverse process occurs, are critical components in a comprehensive analysis of the risk to environmental and human health posed by these metals.