NEW METHODS FOR MODELING THE TRANSPORT OF METALS FROM MINERAL PROCESSING WASTES INTO SURFACE WATERS

The estimation of contaminant fluxes into and within river basins is the aim of this research. These new methods for estimating contaminant loadings and fate on a comprehensive river basin scale based on assembled subsite behaviors have been demonstrated for a collection of Superfund sites in the Upper Clark Fork River basin in Montana. This portion of the demonstration illustrates a new set of techniques for estimating the overland and surface-water movement of mine waste constituents. A linked assessment system -- consisting of contaminant transformation, non-point source and groundwater mixing and transport, surface hydrology and erosion, and surface-water quality models -- has been developed, written, tested, and applied at the site. Principle portions of this assessment system are described. The object of this project is to show the importance of a comparing phenomenological hypotheses with field observations for large-scale exposure models. Graphs of the river copper concentration show a good fit between the measured and predicted concentrations at some stations whereas substantial deviations from field measurements are observed at other stations along the course of the river.