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EPA recaps progress, looks at former mine site

Daily Inter Lake | June 20, 2023 7:00 AM

In a recent meeting in Libby, officials explained what to expect as cleanup efforts begin for the last large area contaminated with asbestos.

In a June 6 meeting, Environmental Protection Agency Community Involvement Coordinator Beth Archer met with residents and officials to give a status update on the former vermiculite mine in the Libby Asbestos Superfund site.

The EPA, which is the lead agency for the asbestos superfund site, but there are two superfund sites in Libby, and they should be distinct.

Archer also explained that the U.S. Forest Service is the lead agency tasked with wildfire response and that Lincoln County is the public health advisor in the event of a fire. W.R. Grace, which is potentially responsible for cleanup costs, is the owner of the former vermiculite mine.

Site cleanup is ongoing and conducted by federal, state and potentially responsible parties.

According to a press release, the site consists of eight areas, called operable units (OUs). These OUs outline the following areas, OU1: the former Export Plant and the Highway 37 embankments, OU2: locations impacted by contamination released from the former Screening Plant, OU3: property in and around the former mine, OU4: residential, commercial and industrial and public properties, OU5: the former Stimson Lumber Company property, OU6: owned and operated by the BNSF railroad, OU7: all residential, commercial and public properties in and around the City of Troy, and OU8: United States and Montana State Highway transportation corridors.

Dania Zinner, remedial project manager for the EPA, noted that about half of OU3 is U.S. Forest Service management land with the other half owned by W.R. Grace.

"The good news is, we've actually delisted or partially deleted about half of the Libby Superfund Site," Zinner said. "So OU3 is our final OU (where) we're focusing on the cleanup."

The EPA is attempting to find alternative cleanup options for waterways and forested areas during the current process, which is a feasibility study phase, Zinner said.

The EPA, the State of Montana, and the Forest Service will all review the feasibility study. The proposed plan will be done by 2025 or 2026, and the EPA will return to Libby to get public comment, Zinner said.

"We make sure that we put a lot of long-term management tools onto a property, just to make sure that the remedy stays protective of human health and the environment into perpetuity, so forever," Zinner said.

After the remediation is completed, there will be an opportunity for the partial deletion or delisting of OU3.

The EPA comes back every five years to make sure the remedy is still working the way it's supposed to be working, protecting human health and the environment, Archer said.

After doing a lot of sampling in OU3, the EPA has determined that recreational activities in OU3 are an acceptable risk to the public, Zinner said.

However, anything that causes dust disturbance during those activities is an unacceptable risk the EPA will have to design a cleanup around, she said.

These disturbance activities include wildland forest fire fighters during mop-ups, commercial loggers creating dust or rockhound trespassers, Zinner said.

Currently, the EPA is trying to figure out the best way to protect the aforementioned groups.

Nick Raines, the remediation project manager for W.R. Grace, spoke about recent changes to the dam in OU3. Raines said that the earthen dam was constructed during mining operations to hold back mine tailings from the operations.

"That dam has been in place, I think construction went from the mid-'60s through the early 90s. We are in the process of making improvements on the dam," Raines said.

He said the improvements that have been made include the redevelopment of a primary spillway to route floodwaters in the event of an extreme storm condition.

The work is continuing, but so far the company has completed a reinforced wall, stabilization of a nearby hillside and backfilled the dam's embankment to the spillway.

Raines said that more information and further evaluation will be conducted to address remaining potential failures. This includes the collection of additional data and further investigation.

Montana Department of Natural Resources's Michele Lemieux, the dam safety section supervisor, announced that the DNRC has regulatory authority over the dam. The EPA is involved, but they don't take over the regulatory insight of critical infrastructure on a superfund site, Lemieux said.

The focus for DNRC is on the structural integrity of the dam and not environmental issues of the dam, Lemieux said. Erosion, which could cause environmental issues, is only looked at through a structural stability point of view, Lemieux said.

The DNRC will not comment on alternative plans but requires only that there is an acceptable risk of dam failure for the public, Lemieux said.

"We're completely supportive of what's being done on the spillway," Lemieux said.

Seepage, how water and materials will move around the dam, needs to be understood before deciding on a rehabilitation approach, she said.

"We're supportive of this cautious approach to collect good information before coming up with some kind of solution," Lemieux said in reference to W.R Grace's current efforts.

On June 7, Zinner briefed the Lincoln County Commissioners on updates to the Libby Asbestos Site.

"We've basically delisted or partially deleted half the site," Zinner said. "It still means the EPA will still do five-year reviews, and the state does annual inspections, but it's a really good milestone to say 'we're done there.'"

"Last time we were here, we heard you guys loud and clear that you would like another five-year review to see how the operation and maintenance program is going for the cities of Libby and Troy residential and commercial properties," Zinner said.

The next five-year review is scheduled for 2025. Eventually, all alternative options will be compiled and open to state and public opinion sometime in 2025, or 2026, Zinner said.

"The most important thing is that we are right now in the screening of remedial options or alternatives. These are our cleanup options for the forested areas, the mine site and waterways for the OU3 former vermiculite mine," Zinner said.