Superfund Record of Decision (EPA Region 8): Silver Bow Creek/Butte Area NPLSite, Warm Springs Ponds Operable Unit, Upper Clark Fork River Basin, MT. (First Remedial Action), September 1990

摘要

The Silver Bow Creek site is a mining and processing area in the Upper Clark ForkRiver Basin, Deer Lodge County, Southwestern Montana. The Record of Decision (ROD) documents the selected interim remedial action for one of eleven operable units for the site, the Warm Springs Ponds operable unit, which covers approximately 2,500 acres just above the beginning of the Clark Fork River. Contamination at the site is the result of over 100 years of mining and process operations in the area. Mining, milling, and smelting waste were dumped directly into Silver Bow Creek and transported downstream to the Clark Fork River with final deposition downstream as far as 130 miles. Principal threats from the site include the possibility of pond berm failure due to flood and earthquake damage that could release millions of cubic yards of tailings and sediment to the river. Furthermore, the creeks are contaminated with dissolved metals, and exposed soil and tailings are contaminated with elevated levels of several metals. The primary contaminants of concern affecting the soil, sediment, ground water, and surface water are metals including arsenic, cadmium, copper, lead, and zinc.