News & Features

Two Years after Troy Mine Shut Down, Cleanup Begins

Hecla Mining Company says it will take three years to remediate tailings impoundment area, demolish processing plant

TROY — Five years ago, the Troy Mine was a beehive of activity tucked below the summit of Mt. Vernon, 17 miles south of its namesake community. Every day, hundreds of miners would venture below the surface in search of copper and silver.

Today, the only sounds at the mostly empty parking lot are the clang of a flagpole and the low hum of a ventilation fan circulating air through the shuttered mine.

But just because the mine site is quiet doesn’t mean it’s deserted. Two years after the Hecla Mining Company announced it was buying the Revett Mining Company and permanently closing the Troy Mine, a massive reclamation project has begun at the site. Doug Stiles, general manager for Hecla’s Montana operations, says the cleanup effort will take approximately three years. When it’s completed, he said it will be hard to tell that a mine ever existed, one that produced 84 million ounces of silver and 430 million pounds of copper over its 35 years of existence.

“A decade from now, there will just be a dirt road through the woods here,” Stiles says.

The mine first operated from 1981 until 1993. Then Revett reopened it in 2005, employing about 200 people to harvest 4,000 tons of ore daily. But three years later, as copper and silver prices plummeted amid the Great Recession, the mine almost shut down. Employees across the company, from its operation in Troy to its corporate offices in Spokane, took pay cuts as the mine limped along for the next few years.

The mine’s outlook started to turn around in 2011, when it processed 1.4 million tons of ore and made $30 million in net cash. In 2012, profits continued to soar, and then-CEO John Shanahan called it “an amazing turnaround.”

But the boom was short lived. In late 2012, a series of underground rock falls closed the mine. Troy, which used a system of room and pillar mining, had struggled with rock falls in the past. In 2007, a miner was killed when part of the mine’s roof collapsed.

Revett spent the next two years trying to stabilize the mine and constructed a new subterranean tunnel that depleted the company’s financial reserves. The mine reopened in September 2014 and officials hoped to resume full production by 2015, but copper prices once again started to dip as demand in China began to decline. In January 2015, copper prices hit $2.55 a pound, its lowest in five years. Revett announced it was going to lay off 70 people and put the mine into “care and maintenance,” essentially mothballing the facility until prices rebounded. Shanahan said Revett would refocus efforts on its proposed Rock Creek project, a much larger mine to the south near Noxon.

Two months later, on March 27, 2015, Hecla announced that it was purchasing Revett and permanently closing the Troy Mine. Based in Coeur d’Alene, Hecla operates mines in Idaho, Alaska, Quebec and Mexico.

Luke Russell, vice president of external affairs for Hecla, says the company decided to permanently close the Troy Mine because of the declining quality of ore that it produced. In 2016, Hecla removed process chemicals from the site and worked on a reclamation plan with the Montana Department of Environmental Quality. This spring, work to implement the plan has begun in earnest.

Reclamation and compliance manager Wes “Skip” Leedy oversees the half-dozen Hecla employees who remain at the site, maintaining pumps and keeping an eye on the mine. The largest aspect of the remediation project is covering the 303-acre tailings impoundment with topsoil. Tailings are a sand-like byproduct of the mining process. Leedy says contractors hope to cover at least 142 acres of the tailings impoundment, located a few miles north of the mine, with 8 inches of topsoil this summer. The rest will be finished next year. After that, contractors will plant trees and grass onsite. More than 354,000 cubic yards of topsoil were set aside in the 1980s when the tailing impoundment was first established.

“Everything we’re doing here is done to return this land back to its natural state,” Leedy says.

Water pumped from the mine is also being sprayed onto the tailings impoundment to keep dust down. More than 3,500 gallons of water are pumped out every minute in the spring from melting snow that seeps through the earth and into the mine. During the rest of the year, approximately 1,000 gallons of water are pumped out every minute. Because water from the mine has an elevated metal content, it must be pumped to the impoundment area where it can be filtered through the tailings.

Hecla workers are also preparing to demolish buildings at the site. A section of the old processing plant, which collapsed under heavy snow this past winter, will most likely be dismantled this year. The administrative building, maintenance shop and other outbuildings will likely be taken down toward the end of the three-year reclamation effort. The mine portals will also be filled in to prevent access. Water-pumping operations will eventually be replaced with a gravity-fed system that sends water down to the reclaimed tailings area. One of the final steps will be grinding up the paved road and reverting it back to a dirt trail. Hecla employees will continue to check the site and collect water quality samples.

While the final chapter is being written at the Troy Mine, Hecla continues to push for the development of two larger mines nearby: Rock Creek, which Hecla also acquired when it purchased Revett, and Montanore, which it bought from Mines Management in 2016.

“Hecla Mining is 126 years old and we see both Rock Creek and Montanore as being a big part of our next 100 years,” Russell says.

Hecla is currently waiting for a record of decision from the U.S. Forest Service that, if approved, would allow it to move forward with developing the Rock Creek Mine. Montanore, located south of Libby, received a green light from government regulators last year, which was then overturned in May by a federal judge who ruled the U.S. Fish and Wildlife Service and the Forest Service had violated federal law by approving construction of the proposed copper and silver mine. Russell says Hecla officials are “disappointed but not deterred” by the court’s ruling and have vowed to work with regulators to resolve any environmental concerns.

Environmental groups have long raised concerns about the development of the Rock Creek and Montanore mines, particularly because both are located directly underneath the Cabinet Mountain Wilderness. Karen Knudsen, executive director of the Clark Fork Coalition, says the mines could permanently dewater streams in the wilderness above.

If developed, the two mines could produce more than 500 million ounces of silver and 4 billion pounds of copper in their lifetime. The two deposits are separated by about 7,000 feet of earth and a fault line, suggesting that at one time it was actually one ore body.

Russell says although it’s now closed, the Troy Mine is playing an important role in Hecla’s effort to open the other two mines.

“The Troy Mine gives us an opportunity to show the community what modern mine reclamation can be,” he says. “This mine is a great analog for what the Rock Creek and Montanore mines will look like.”