Damned if you do 

Where to bury the Mike Horse Dam's toxic tailings?

This spring, Mike Grimes, who lives on 140 wooded acres off Highway 279, east of Lincoln, found that his well became artesian, flooding his property and threatening to swamp plans to host his son's wedding there. But what was equally disconcerting, he says, was the overflowing well across the road, on land where the state wants to entomb a million cubic yards of toxic mine tailings from the nearby Mike Horse Dam. The dam is part of a state Superfund site that sits at the headwaters of the Blackfoot River. "If they're successful putting this over there," Grimes says, "they are going to be working with groundwater every spring, and it's going to carry the contaminants onto my property, into Nora Creek, and into the Blackfoot."

click to enlarge MAP BY JONATHAN MARQUIS

Grimes might be the most vocal critic of the Montana Department of Environmental Quality and U.S. Forest Service's preference to haul the tailings to a 365-acre piece of ground known as Section 35. On Sept. 21, the agencies released their long-awaited Repository Siting Study, which identifies Section 35 as the most suitable site among the 10 they've evaluated over the last few years.

The document comes 36 years after the earthen Mike Horse Dam gave way, washing 100,000 tons of fine-grain tailings laced with silver, gold, zinc, lead, cadmium, iron, copper and arsenic into Beartrap Creek and the upper Blackfoot River. The devastation led to a $37 million settlement between the state and American Smelting and Refining Co. and Atlantic Richfield Co., the operators of the long-defunct Mike Horse Mine.

The siting recommendation, which is now open for public comment, puts a "big twist" in Grimes's gut, he says, since it portends dump trucks making some 40,000 roundtrips between the Mike Horse Dam and a 30-acre impoundment, just across the road, over the course of the next decade. But the agencies found that there aren't suitable alternatives within the upper Blackfoot watershed that are more protective or cost less. The area's mountainous terrain and marshy creek bottoms doesn't lend it to landfills. Section 35's benched topography, the agencies say, is the best bet—even if there are worries about the depth to groundwater.

"Obviously, anywhere where there's groundwater, there's a certainly a concern," says Shellie Haaland, the DEQ's reclamation specialist on the project. She acknowledges that there are some places on Section 35 unsuitable for a repository, but other test wells have shown depths to groundwater as great as 70 feet. "What we'll have to do is put in some piezometers and make sure we understand how the groundwater is reacting across the board," she says.

NIMBYism is at the core of Grimes's and some of his neighbors' opposition to the burial of tailings across the road. But there's also suspicion, even after the release of an exhaustive, 83-page evaluation, that the state arbitrarily prefers Section 35. Stimson Lumber Company owns the land, and it owes the state $300,000 for environmental cleanup work at its Bonner mill, at the other end of the Blackfoot River. The struggling timber company has offered to give the state Section 35 to use as a repository in lieu of payment.

Also fueling suspicion is the fact that Section 35's mineral rights and restrictive easements are held by the nearby Sieben Ranch, which is owned by John Baucus, brother of U.S. Sen. Max Baucus. DEQ Chief Remediation Counsel Bill Kirley says that if the state ultimately selects Section 35, the ranch would be paid $255,000 to relinquish its rights. John Baucus and the state finalized the deal in the last few weeks.

"We have talked with them and talked with them and tried to reason with them that this is a crazy place to put a repository site," Grimes says of the agencies. "Regardless of my personal involvement in it, the repository is bordered by the Blackfoot River and a tributary, and it's full of groundwater."

But the other options have perhaps more significant drawbacks. Take Paymaster, an existing repository created years ago by ASARCO that could be expanded. It's very close to the dam, which reduces transportation costs, but it's only about 50 feet from the Blackfoot and would require expensive engineering due to the steepness of the terrain. According to the study, Paymaster would cost between $11 and 13 million, while Section 35 would cost about $10 million.

Grimes, for one, believes the tailings should stay right where they are, above a wastewater plant that treats the drainage still coming out of the old mines.

"It's pretty clear that nothing that they're looking at so far is ideal," says Chris Brick, science director of the Clark Fork Coalition. "There are some tough realties to consider. We absolutely need to get the safest repository we can get—safest environmentally and safest with respect to human hazards. But we also have to be careful to not squander the money that the state has for the site, because there is a limited pot of money there. And we can't wait forever. They saw significant water up there [at the Mike Horse Dam] this year...It was scary," she says, waiting to see if the dam would fail again, as it did in 1975.

Public comments on the relocation of the Mike Horse Dam's tailings are due to the Helena National Forest by Oct. 21. Haaland urges people to weigh in on all of the possible repository sites, not just Section 35, because "there's potential that we'll go out there and find something we didn't expect, and have to go to the next one on the list."

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