Wednesday, August 03, 2005

ENV: Cleaning up the homeland

Dam and Waste Will Go, Freeing Two Rivers
By JIM ROBBINS, August 4, 2005, The New York Times

HELENA, Mont., Aug. 3 - Since 1907, the Milltown Dam just east of Missoula, Mont., has held back two of the state's major rivers and trapped tons of toxic mining waste that once washed down one of them from more than 100 miles upstream.

An agreement announced this week, however, will allow work to begin on the removal of the decaying timber-and-stone structure and the waste behind it. The job is a technically challenging one that aims to restore the two rivers, the Blackfoot and the Clark Fork, to free-flowing conditions by 2009 at a cost of about $100 million.

"This is a historic construction project, and it will set a standard for impaired rivers worldwide," said Gov. Brian Schweitzer, who helped negotiate the deal and celebrated at the dam Tuesday with a glass of Champagne "If that dam were to break, there's no telling what would happen. It wasn't built to last this long."

Three years of negotiations centered on who would pay how much for the removal of the waste, which previously flowed from one of the country's largest copper mines, by now long shuttered. Under the deal, the Atlantic Richfield Company, which in 1977 inherited a legacy of pollution here in buying the Anaconda Copper Mining Company, the mine's previous owner, is to pay $80 million; Northwestern Energy, which owns the dam, $11.6 million; and the State of Montana $7.6 million.

After a 30-day period of public comment, a federal judge will decide whether to approve the agreement, as expected.

The dam, which by today's standards produces a negligible amount of power, backs up both the Clark Fork and the Blackfoot, the river that was made famous in Norman MacLean's novel "A River Runs Through It." The first step in the project could begin this fall, with the digging of a new channel into the Black Foot to reroute the Clark Fork upstream of the dam temporarily, allowing removal of waste.

When the dam itself is removed and the natural flow restored, many miles of river will again be opened up to spawning by bull trout, a threatened species, and other fish.

"We're thrilled, just thrilled, that we're putting a river back together," said Tracy Stone-Manning, executive director of the Clark Fork Coalition, which has campaigned for years to have the river cleaned up and the dam removed. "It will create jobs, but more importantly there'll be an asset - the confluence of two major rivers - and not a liability. It's going to be beautiful when all is said and done."

A $5 million authorization in the highway bill approved by Congress last week will finance the creation of a park at the confluence, as well as trails and new wetlands.

Dams of this size and larger have been removed from other rivers. "But this one is tricky because of the contaminated material behind the dam," said Matt Fein, project manager for Envirocon Inc., the contractor.

For more than seven decades after the dam was built nearly a century ago, it was the last stop for copper, cadmium, arsenic and other mine waste that washed down the 120-mile-long Clark Fork River. Levels of copper along the Clark Fork are now so high that in some places the riverbank, floodplains and bones of dead cattle are bright green.

Behind the dam, spread out in the reservoir, are more than six million cubic yards of heavily contaminated soil, at some spots nearly 30 feet deep. Contractors first must reroute the Clark Fork so it flows into the Blackfoot before they remove soil and the dam. Then they will return the Clark Fork to its channel.

The project requires trucking away about a third of the mine waste. The rest will be stabilized and left in place.

One reason for the removal is that arsenic behind the dam has flowed into groundwater and contaminated the wells of several dozen residents in nearby Milltown. Atlantic Richfield was forced years ago to drill a new, very deep well to create safe water. Once the dam and the reservoir are gone, said Mr. Fein, the project manager, the aquifer should clean itself out in 4 to 10 years.


Post a Comment

<< Home