Project Summary (2000-2005)

The project is conducting research aimed at understanding the fate and transport of select Superfund chemicals (chlorpyrifos, diazinon, and pentachlorophenol) and their degradation products. The surface and subsurface in and around two Superfund field sites is being characterized on a range of scales. Inverse modeling in laboratory column studies is estimating the physico-chemical properties of the subsurface and the parameters describing equilibrium and non-equilibrium interfacial processes. Other models are also being tested and new forward and inverse mathematical models to describe the fate and transport of RWT and test contaminants are being formulated. Choice of model will be confirmed using systematic comparisons of the parameter estimates and characterizations obtained from a range of scales. Field characterization of solute transport is being conducted using field injection tests with a fluorescent tracer at the test Superfund sites. This information is being used to formulate a field-scale stochastic fate and transport model with the capability to estimate concentration exceedence probabilities in groundwater and surface waters (and related human and wildlife exposure) in close proximity to test Superfund sites.