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Missoula County approves Stimson plan to clean up pond, restore riverbank

Missoula County approves Stimson plan to clean up pond, restore riverbank

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All systems are go for the removal of a PCB-laced cooling pond that sits in the Blackfoot River at a mill site a mile above the river's mouth.

Missoula County commissioners on Wednesday approved a variance from floodplain regulations that will permit Stimson Lumber Co. to restore the historic riverbank using large rocks, or riprap - something that's been prohibited by the county except for special cases for the past 10 years.

The unanimous vote on the first day of autumn was the final hurdle in a process lined with permits since Stimson agreed to the cleanup in April.

By winter, Envirocon Inc. of Missoula figures to have 1,400 feet of the Blackfoot channel looking much as it did in 1884, before a dam was built to block the annual log drive to the Montana Improvement Co.'s mill.

Keith Large of the Montana Department of Environmental Quality said cleanup preparations have been under way for a couple of weeks, and trucks could start hauling away covered loads of dirty dirt as early as Friday.

Most of the estimated 30,500 cubic yards to be disposed of will go to the Allied Waste landfill in northwest Missoula. About 3,500 cubic yards of the most contaminated soil will be shipped to a special facility in Idaho, and 6,500 cubic yards of the cleanest stuff will be placed on a new repository on mill property.

Final remnants of the mill dam were removed in October 2005, when the large cooling pond was discovered. Stimson, the mill owner then and now, didn't have anything to do with construction of either.

"We inherited this," said Steven Petrin, Stimson's environmental manager, said after testifying in favor of the restoration plan at Wednesday's hearing.


The Portland, Ore.-based company, on the hook for the entire $6.5 million cleanup, is suing successors of its two immediate predecessors - the Anaconda Copper Mining Co. and Champion International - to help pay for removal of the cooling pond.

In the Anaconda's case that's Arco/BP, the same company held responsible for the recent cleanup of the Milltown EPA Superfund Site just downstream. Champion International, which owned the mill from 1972 to 1994, was bought out in 2000 by Memphis-based International Paper, the largest paper and pulp company in the world.

Stimson is also being sued - by the state of Montana.

"We're suing them for encroachment on the streambed," Large said. "When they get through with everything and a new floodplain map gets filed, the state can withdraw the lawsuit.

"It's in our best interest and Stimson's best interest to expedite that as soon as possible, so it's not hanging over the property," added Large. "Everybody wants to get rid of that lawsuit."

A Missoula paint business, Northwest Paint Inc., leased one building at the mill site earlier this year, and Petrin said Stimson is still actively seeking more renters or a buyer.

After cleaning out the former cooling pond, a process that will take some six weeks, Envirocon will remove the berms in the river that contain the pond and rebuild the original riverbank.

Todd Klietz of Missoula's Office of Planning and Grants told commissioners the goal is a bank 6 feet high. Boulders 3 feet in diameter will be placed at the base. Above them there'll be rocks 2 feet in diameter interspersed with soil and native vegetation. Revegetation efforts will take place next spring.

Riprap was prohibited by Missoula County in 2000 in part because it tends to deflect stream flow and erosion to the opposite bank downstream.

"We're essentially doubling the channel width there, so we don't have the concerns we typically would have with riprapping bank - increasing velocity and potentially increasing flood heights and damage to downstream properties," Klietz said.


The Missoula Floodplain Regulation Board of Appeals may grant a permit that's not in compliance with floodplain regulations if each of eight conditions is fulfilled. Those conditions include determinations that the riprapping won't lead to flooding, and that the variance has approval from the Montana Department of Natural Resources and Conservation. Klietz said the DNRC approved the riprap plan on Friday.

Peter Nielsen of the City-County Health Department said his

office approves of the floodplain variance.

"I think in this instance some use of large rock is appropriate to protect that site, which will remain industrial in the future," he told commissioners. "A good compromise has been reached."

Nielsen also lauded what he called "a robust revegetation effort" on a river that doesn't yet have an active restoration plan.

"It's going to be one of the nicest stretches of the river there once it's all done and maintained," he said.

The floodplain permit from the county was the necessary last step in permitting, Large said.

The cleanup plan has already received formal approval from the U.S. Environmental Protection Agency and the U.S. Army Corps of Engineers (including a bull trout biological assessment), as well as the DNRC, DEQ's Water Protection Bureau and Fish, Wildlife and Parks at the state level, and the Missoula Conservation District.

Reporter Kim Briggeman can be reached at 523-5266 or at


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