High water this month is once more raising concerns about old berms from the former Smurfit Stone mill collapsing, and sending contaminants from decades of operation into the Clark Fork River.

But officials with the Environmental Protection Agency are offering re-assurances, saying they've updated a new plan designed to monitor the conditions of the berms and keep principal agencies informed of any problems.

The berms are decades old and were designed during the mill's operation to separate settling ponds, aeration basins, and other areas from the Clark Fork along the southwestern boundary of the 3,200-acre site.

There had been concern about the conditions of the ponds for several years after the mill ceased operations in 2010, especially because no one was on-site to take care of regular maintenance. Local government leaders and conservation groups are worried because the 800 acres of ponds are "unlined", allowing them to interact with groundwater.

But the fears were heightened during record floods in 2018.

Although the berms weren't breached during the '18 floods, it drew additional attention to the berms, and the arsenic, manganese, and other materials still needing potential cleanup.

EPA developed a Clark Fork Berm Surveillance & Contingency Plan, which orders regular monitoring during high water events like we're having this month and outlines how different parties will be involved, and respond if problems develop.

Dennis Bragg photo
Dennis Bragg photo

Plan sets levels for monitoring for berm failure

EPA's Community Involvement Coordinator Dana Barnicoat sent out an announcement last week, offering reassurances. She says weekly inspections are ready to begin anytime the gauge above Missoula exceeds 10.5', which hasn't happened yet this year. Daily inspections are made if the river tops 11'. And she says the berms are inspected once a month in April, May, June, and July "regardless of Clark Fork River flows."

She says the plan outlines the immediate actions to be taken if any stability problems are discovered in "multiple scenarios", with water samples being taken to see if any of the contaminants are getting into the river.

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