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Know the West

The Clark Fork unplugged


On Montana's Clark Fork River, pressure is mounting to demolish a dam.

The Milltown dam sits seven miles upstream from Missoula, where the Blackfoot River and the Clark Fork meet. For years, it has acted as a plug, holding back 6.5 million cubic yards of sediment contaminated with arsenic and heavy metals washed away from mines and smelters in Butte and Anaconda, 120 miles to the southeast (HCN, 1/19/98: Turning the Old West into the New West).

Experts thought the dam was a safe repository for the drifting poisons. But in February 1996, a massive ice floe scoured the reservoir's bottom and filled the river with copper and other contaminants. Downstream fish populations took a nosedive.

The dam also prevents endangered bull trout from migrating up or down the river, and this spring the Environmental Protection Agency announced it may order the dam removed and the sediments cleaned up. The EPA has asked the U.S. Army Corps of Engineers, which has studied breaching four dams on the Snake River, to evaluate the situation.

Local environmentalists, health officials and the Missoula County commissioners support the cleanup. Montana Power Company, the dam's owner, told the Federal Energy Regulatory Commission it has no interest in generating electricity at the 2-megawatt plant, and has done nothing to dissuade the discussions of tearing it out.

If the dam is removed, truckers would have to move 150,000 loads of contaminated soil. The EPA has identified a potential dump in the hills north of Missoula. But at least one environmental group says the toxic sediments should be shipped back where they came from - to a Superfund site outside Anaconda.

"Any place is bound to be better than the confluence of two rivers," says Tracy Stone-Manning, director of the Clark Fork Coalition.

Copyright © 2000 HCN and Mark Matthews