WHITEFISH – State and federal regulators have settled on a controversial repository site they believe will safely contain 1 million cubic yards of toxic mine tailings that are shored up behind the Mike Horse Dam.

The $39 million project to remove the dam, an earthen berm at the headwaters of the Blackfoot River, and extract the impounded waste behind it has been on hold while the Montana Department of Environmental Quality searches for a safe repository.

And although agency officials say they still must conduct a more detailed investigation of the site – a 360-acre triangle on the east side of Highway 279, called Section 35 – they said Monday it appears to be the best option.

Kevin Riordan, Helena National Forest supervisor, said selecting a repository site was a yearlong process. Now that it’s complete, monitoring wells will be installed to learn more about the springtime behavior of the water table to avoid any interaction with the mine wastes.

Riordan hopes to begin construction by fall 2013 and perhaps start hauling the waste in 2014, but says the projection is optimistic.

“If it happens the way we think it will happen we will be able to lay a repository that will be protected into the future,” he said. “Otherwise we will have to rethink things. But we won’t know that for sure until we perform that further analysis.”

Section 35 is located about eight miles from the dam and in close proximity to Lincoln residents, many of whom opposed the repository site.

Mike Grimes’ home sits across the road from Section 35, which is owned by Stimson Lumber Co.

“Section 35 is not the right answer – it is too close to the Blackfoot, too close to tributaries of the Blackfoot, contains too much ground water, exhibits too much springtime groundwater fluctuations, and is too close to private property, some of which is immediately down gradient,” he wrote during the public comment period last September. “Placing these tailings within close proximity of so many private property owners will significantly degrade the value and enjoyment of their property, will violate the owners’ right to a Clean and Healthful Environment guaranteed by the Montana Constitution, and will result in Inverse Condemnation their property.”

One group of private residents, calling itself Help Save the Blackfoot, gathered 153 signatures opposing Section 35.

“Our objections to the actions of the two agencies go far beyond any personal concerns that arise simply because we happen to live in the neighborhood,” according to the group’s website. “As private citizens of this valley our greatest concern is not just our property values or personal inconvenience, but rather the long-term impact to the water quality, fisheries and wildlife and eventual cost to tax payers when this magnificent river is polluted once again.”

Nearly everyone agrees that the tailings must go somewhere, however, and that need was underscored in spring 2011 when the tailings nearly broke loose due to snowmelt and groundwater – a near repeat of the Mike Horse Dam failure of 1975 that poisoned the river for years, causing fish kills and environmental damage for miles downstream.


A settlement with ASARCO helped the agencies obtain $39 million to address the cleanup, and the U.S. Forest Service and Montana DEQ originally proposed a suitable repository at the Paymaster site. However, a design-level investigation raised concerns about the site and the agencies began looking for an alternative.

The selection of Section 35 initially gave pause to Chris Brick at the Clark Fork Coalition, a Missoula-based nonprofit that has been involved with Mike Horse for years. Having reviewed all of the data, however, she is confident that the DEQ is trying to balance the challenges, and that Section 35 is the best option out of all the proposed sites.

“I think it’s the right decision, and I think it is potentially quite feasible,” Brick said. “They are doing further investigation which is good, because if they find that the groundwater is too high it would be back to the drawing board. But they feel pretty confident that it will work out.”

Brick said that, at 360 acres, Section 35 site is much larger than what they need for the 30-acre repository, allowing flexibility in the design process.

“I am really glad that the project is moving forward because certainly where the tailings are now is not a safe place for the long term,” she said. “I think they have done a pretty good job making sure that a disaster doesn’t happen.”

Richard Opper, director of the Montana DEQ, said it’s not surprising that the site selection has been met with controversy, but he said the agencies will work to mitigate the concerns of community members.

“There is going to be controversy associated with any site, so it’s not much of a surprise,” he said. “There are certain criteria we had to look at, and in looking at multiple sites Section 35 is the best fit.”

The site must be relatively close to contamination to cut down on use of roads and haul costs, and it needs to have enough capacity to hold all of the contaminated material. There also must be a degree of separation from the groundwater, he said.

“There is no perfect site,” he said. “But when you take everything into consideration, Section 35 was the clear choice.”

Riordan said with the decision out of the way, the agencies can take steps to work with Lincoln residents and try to mollify their concerns about traffic delays and contamination.

“There are going to be short-term impacts no matter how you slice it. But we don’t want land managers having to worry about this 50, 60 or 100 years from now,” Riordan said. “We believe we have found a safe, stable, protected area where groundwater interaction will not occur.”

Reporter Tristan Scott can be reached at (406) 730-1067 or at tscott@missolian.com.

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(1) comment


I wonder if Mike Grimes supported mining until they decided to dump tailings on his doorstep. All mining proposals need to be held to a higher standard because almost every project is abandoned leaving the cleanup and the managing of the waste to the public. Owners make the millions then slide back into the cesspool from whence they came.

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