from The Seattle Times

Every evening, a 45-car train rumbles away from the Clark Fork River, loaded not with copper, gold or silver ore, but with the toxic legacy of more than a century of mining: tons of contaminated mud from behind an old dam.

Workers are removing 2.2 million cubic yards of the muck _ and dismantling the 101-year-old Milltown Dam _ in a breathtakingly scenic part of Montana trout-fishing country celebrated in Norman Maclean's novel "A River Runs Through It."

For decades, metals released into the river by mining and ore-processing in the Butte area collected downstream in the sediment behind the hydroelectric dam, where the toxins are now threatening fish and polluting drinking water in the ground below.

The dam is part of a big swath of southwestern Montana that has been designated the nation's largest Superfund cleanup site.

"Simply stated, 100 years ago they took hundreds of millions of dollars of gold and silver and copper out of the side of the mountain and they left us with a century of pollution," Gov. Brian Schweitzer said. "The money from the minerals went to Wall Street and the pollution went into Montana rivers."

Atlantic Richfield Co. assumed financial responsibility for the Milltown Dam site after a 1977 merger with Anaconda Co., the mining giant. ARCO is covering most of the estimated $120 million cost of the cleanup, with the state, the Environmental Protection Agency and a local utility paying the rest.

In the late 19th century, Butte was the world's copper king as America wired itself for the electric light, the telephone and other innovations. Nearly 22 billion pounds of copper were extracted from 1880 to 2005.

The contamination went undetected until 1981, when a county health official found high levels of arsenic in the water supply. Studying the problem, deciding on a fix, negotiating the funding and launching the work extended well into the 21st century.

Full Story: http://seattletimes.nwsource.com/html/nationworld/2004290275_
apmudtrain.html