ABSTRACT
Watersheds in mining districts in the western United States are frequently impacted by metals and other inorganic constituents released during extraction and processing activities. Metal-enriched materials, such as soil eroded from exposed and disturbed landscapes and tailings generated during processing, may be released to the environment and associated with increased metal concentrations in surface water and groundwater. Similarly, dispersed sediments may have been deposited as alluvial materials in riparian areas, yielding soils having metal concentrations much greater than predepositional conditions. The present chapter summarizes ecological risk assessment studies focused on metal-contaminated soil, sediment, and surface water for a series of Superfund sites located in the Clark Fork River (CFR) watershed of western Montana (Figure 30.1).
