Following the fish kill, tests by Missoula's Health Department found greatly elevated levels of copper, zinc and arsenic in the once-dammed waters. Metals in the Milltown Reservoir were accumulated during more than a century of mining and smeltering upstream, in Butte and Anaconda (HCN,10/30/95).
But EPA officials haven't changed their position. They said removing the contaminated sediment is still not worth the money, a conclusion shared by Atlantic Richfield Co., which now owns the site. Instead, the agency wants to dig monitoring wells to track the plume of pollution as it moves past the dam. The wells would signal EPA when to tell people their drinking water was becoming contaminated.
* Mark Matthews