Water Resources Research Act Program

Details for Project ID 2002ID1B

Metal(loid) Release from Contaminated Sediments in Lake Coeur d'Alene, Idaho

Institute: Idaho
Year Established: 2002 Start Date: 2002-03-01 End Date: 2003-02-28
Total Federal Funds: $14,997 Total Non-Federal Funds: $29,996

Principal Investigators: Matthew Morra

Project Summary: Lake Coeur dAlene (CDA) in Idaho is the second largest natural lake in the Inland Northwest. Lake CDA provides drinking water for at least five communities and serves as a primary ecreational area for inhabitants of the Pacific Northwest. Over the last century Lake CDA became and continues to be, the major collecting bed for contaminated sediments produced during mining and ore processing activities. As a result of these mining activities tailings enriched in Pb, Zn, As, Cd, and other trace elements were deposited in stream banks and bars along the South Fork and main stem of the Coeur dAlene River. These materials have been regularly resuspended during periods of high stream flow and secondarily transported into Lake CDA. The USGS has estimated that as much as 85% of the lake bottom is contaminated with metal(loids) (Horowitz et al., 1992). The overriding concern of management agencies responsible for lake water quality is the potential release of the accumulated metal(loids) into the overlying water column.