At toxic Montana dam, a river now runs through it

Jeff Hull, Reuters 29 Mar 08;

MILLTOWN, Montana (Reuters) - Engineers breached a hydroelectric dam in Montana on Friday, the first time an American dam was removed to clean up toxic sediments captured behind it from years of mining upriver.

The intent was the restore some of the pristine beauty of the water as portrayed in "A River Runs Through It," Norman McLean's classic novel about fly fishing later made into a film directed by Robert Redford.

In the novel, the Blackfoot, one of the rivers dammed in Milltown, is portrayed as a frontier of unspoiled outdoor recreation.

In reality, the reservoir behind the 720-foot-(220 meter)wide, 21-foot-(seven meter)high Milltown dam east of Missoula held 6.6 million cubic yards of sediment laden with arsenic, zinc, copper and other heavy metals. The sediments came from a century of mining at the river's headwaters in Butte, 120 miles upstream.

Its breaching represents the first time a dam has been taken out specifically as part of a multiyear process to clean up a toxic river bottom. The lower water level with the dam gone will allow engineers easier access for cleaning.

Contractors will spend several years digging up toxic sediments 25-feet-(eight meter)deep in some places. Eventually, the former reservoir is slated to become a recreation area.

In Montana, as in many Western states, cleaning up after mining has become a big business. The Milltown dam's removal is part of a $500 million Superfund clean up project, led by the U.S. Environmental Protection Agency.

"They used to say it's jobs or the environment," said Montana Governor Brian Schweitzer. "Take a look at those yellow tractors. Those are jobs restoring the environment."

Since 1999, 253 U.S. dams, mostly small irrigation dams, have been removed, 54 in 2007 alone, according to American Rivers, a conservation group. The Milltown dam, spanning the confluence of the Clark Fork and Blackfoot rivers, was one of the largest removed in recent years.

Gov. Schweitzer spoke moments before the breaching, which was started when an excavator scooped away the last remaining plug of a temporary dam put up to remove the main dam. The rush of water gradually eroded the rest of the dam.

Montana Senator Max Baucus, also speaking at the dam site, noted its importance in the economic development of Montana and the nation.

Built in 1907, the dam powered a timber mill owned by William Clarke, one of three mining magnates known as the Copper Kings. Timbers from the mill built mines which yielded the copper that served as the country's first electrical and phone wires networks.

"But the jobs of restoration, and also the jobs of hunting and fishing, those are the jobs of the future of Montana," Baucus said.

The Stimson Lumber Company closed a timber mill that occupied the same site as Clarke's just 10 days ago as the region focuses more on tourism and recreation. Another large timber producer, Plum Creek, is subdividing its forest land holdings for sale in Montana's lucrative recreational real estate market.