Project ID: 2002ID1B

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

Project Type: Research

Focus Categories: Sediments, Toxic Substances, Surface Water

Keywords: heavy metals, mining sediments, contaminant flux

Start Date: 03/01/2002

End Date: 02/28/2003

Federal Funds: $14,997

Non-Federal Matching Funds: $29,996

Congressional District: 1

Principal Investigator:
Matthew Morra
University of Idaho

Abstract

Lake Coeur d'Alene (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 d'Alene 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.

Progress/Completion Report PDF