PINEHURST, Idaho – Steel bars block the arched opening to the Constitution Mine in Idaho’s Silver Valley, a reminder that people for decades would hold beer parties in the cavernous elevator room.
The former lead and zinc mine has been inactive since 1968, but the U.S. Environmental Protection Agency this summer began the task of cleaning up the remote site to make it safe for recreational use.
It’s part of a massive decades-long cleanup of the Silver Valley, the second-largest Superfund site in the nation after Butte and Anaconda, Mont.
“There were over 100 producing mines and 50 mill sites in this basin,” said Bill Adams, manager of the Superfund project for the EPA. “A lot has been done and there is more to do.”
Indeed, cleanup of the entire Bunker Hill Superfund site is expected to take more than three decades and cost more than $350 million because the environmental degradation here was so immense.
While plenty of work has already been done in the vicinity of the Bunker Hill mine and mill, in Kellogg, Idaho, work is now moving into the surrounding areas.
In 2003, four sites were identified as having the greatest potential to harm human health. Those included the Constitution Mine, the Rex mine and mill, the Golconda site, and the Sisters waste-rock dump.
Cleanup is completed at the Sisters site, and work on the other three is under way.
Not everyone is impressed.
Barbara Miller, who has long pushed the federal government to clean up the Silver Valley, said work should focus on populated areas, rather than abandoned mines.
“EPA is doing a fairly decent job of remediation efforts to soil and water,” said Miller, who lives in Kellogg. “But there is much more that needs to be done in the way of health intervention.”
The agency should concentrate on removing lead contamination from lawns and the inside of homes, she said.
“That’s where children first become exposed,” said Miller, who founded the Silver Valley Community Resource Center in Kellogg more than a decade ago.
Ed Moreen of EPA said cleaning up residential yards and other urban pollution remains the top priority. But cleanup must also occur in remote places where people voluntarily gather, he said.
“The Constitution Mine is one,” Moreen said. “They were prioritized because of that.”
While all four sites were once associated with the heavy industry that dominated the valley for a century, the greatest danger these days is to people who hike or ride to the former mine sites. Dirt bike and ATV riders race up hills of mine tailings that are contaminated with arsenic and lead, the EPA said. They kick up dust that can be inhaled.
The Silver Valley runs across the Idaho Panhandle, ending some 50 miles east of Spokane, Wash. For much of the 20th century it was a major producer of silver and other precious metals. Most of the mines have closed, but mountains of pollution remain.
Adams estimated that 25 percent of the resources of the EPA’s regional office in Seattle is spent in the Silver Valley.
Last year, a National Academies of Science report concluded that the only way to extinguish a “legacy of contamination” is a massive cleanup. The study endorsed the EPA’s plan to spend $359 million to expand the cleanup beyond the Bunker Hill smelter and mining complex in Kellogg.
EPA began cleaning the smelter site in 1983 and has spent more than $250 million thus far.
The Constitution Mine was first staked in 1901, and milling began there in 1916. Miners dug for lead, silver and zinc. Production ended in 1968.
The mine, seven miles south of Pinehurst, is a microcosm of everything the EPA faces in the Silver Valley. There’s a mine opening to close up, piles of contaminated rocks to stabilize, a badly polluted mill foundation to deal with, and huge piles of tailings to be covered and capped.
Mine wastes are kept on-site as much as possible, Adams said.
The plan calls for gathering up all the contaminated soil and tailings and placing them in one spot, capping them with a claylike substance and then seeding them for vegetation cover. The site will be contoured so that water runs off without carrying contaminants into streams.
Flooding is a major concern, as zinc and arsenic can be carried into rivers, downstream to Lake Coeur d’Alene and into the Spokane River in Washington.
The metals have killed migrating birds and led to warnings about eating fish.
At the Constitution Mine, the government is also experimenting with a “bioreactor” concept that uses a combination of horse manure, rock and straw to produce bacteria that consume heavy metals in soil. Up to 90 percent of the metals are removed using this method, said Dave Fortier of the Bureau of Land Management.
“The concept is working,” Fortier said. “We’ve got four of them going.”
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