Water

Idaho's unsettling sediment

John Rosapepe Feb. 7, 1994 From the print edition

A new government study shows that Idaho's Lake Coeur d'Alene is one of the most contaminated bodies of water in the world. The U.S. Geological Survey estimates that 85 percent of the 50-square-mile lake bed is contaminated with 75 million metric tons of sediments containing silver, copper, lead, zinc, cadmium, mercury and arsenic. The contamination comes from mining and ore-processing in the Coeur d'Alene mining district between 1895 and 1910. Until 1968, most of the wastes were discharged directly into the South Fork of the Coeur d'Alene River, which drains into the lake. Although the EPA established the 21-square-mile Bunker Hill Superfund site in 1983, the agency neglected contamination downriver and in the lake. Today, the lake is popular with recreationists, but most of the lake bed is devoid of life.

Copies of The Effect of Mining and Related Activities on the Sediment Trace Element Geochemistry of Lake Coeur d'Alene, Part I: Surface Sediments and Part II: Subsurface Sediments can be obtained from Dr. Horowitz, U.S. Geological Survey, Peachtree Business Park, Suite 130, 3039 Amwiler Road, Atlanta, GA 30360 (404/903-9100).

* John Rosapepe