Progress continues at Smurfit-Stone Mill Site in Frenchtown, Montana, as EPA plans further studies and sampling this year

Progress continues at Smurfit-Stone Mill Site in Frenchtown, Montana, as EPA plans further studies and sampling this year

July 31, 2024

FRENCHTOWN, Mont. - The U.S. Environmental Protection Agency (EPA) recently directed two additional sampling events with a third now underway at the Smurfit-Stone Mill Site, a former paper and pulp mill located 11 miles west of Missoula, Montana.

Since 2015, EPA has directed and overseen extensive site investigation by potentially responsible parties (PRPs) under the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) to determine the nature and extent ofcontamination on the site resulting from the mill's operations.

In 2023, stakeholders and Missoula County requested that EPA consider additional groundwater and soil sampling to address their concerns about potential sources of polychlorinated biphenyls (PCBs) and site characterization. Data collected over the next year will support that request and inform the upcoming remedial investigation. Once the remedial investigation is complete, EPA can begin to develop and evaluate cleanup plans-also called remedial alternatives-in the feasibility study report for the site.

"The EPA Superfund process is both long and complex to navigate," said Community Advisory Group (CAG) Administrator Jeri Delys. "The Frenchtown Smurfit-Stone CAG has been the steady force behind ensuring the site is cleaned up in a timely and thorough manner, and the interests of our community and our state are put front and center. To that end, the EPA agreed with the CAG and Missoula County that additional site characterization would be necessary to help define and ensure the best possible outcome for the site, the community and surrounding areas. Throughout the additional site characterization process, the CAG continues to engage with the EPA on upholding fair decision-making processes that best represent the interests of the community and the state."

EPA is overseeing these recent sampling efforts to further consider the potential presence of PCBs, a group of chemicals that were used in industrial applications-such as in hydraulic fluids-for decades across the U.S. before their production was banned in 1979. Future sampling events, including a groundwater/surface water interaction study taking place over the next two weeks, seek to further investigate geochemical conditions controlling the migration of manganese and arsenic through groundwater to the Clark Fork River. This sampling will also help with the understanding of potential risks to fish or other aquatic life in the river.

"Robust and comprehensive site investigation, as well as community involvement, are essential pieces of the Superfund process," said Carolina Balliew, EPA Region 8 Montana Remedial Supervisor. "We are excited about the progress made over the past year with our site partners at the state, county and local levels as we direct additional sampling efforts that help build on site knowledge and move us forward in a positive direction."

In May, crews installed 10 new groundwater monitoring wells and sampled a total of 58 groundwater monitoring wells for a full suite of analytes, including 209 PCB congeners, PCB Aroclors, dioxins/furans and metals. Crews drilled boreholes in primary sludge ponds and solid waste basins to further characterize soils and the presence or absence of these contaminants of potential concern (COPCs). Samples were also collected from the native soils underlying the sludge ponds and solid waste basins to determine if COPCs are potentially migrating through soil. Understanding where contaminants are located and how they migrate is necessary for developing remedial alternatives to mitigate any unacceptable risk identified at the site.

These sampling events follow a fall 2023 groundwater sampling event in which 33 groundwater monitoring wells were sampled for the same COPCs. The sample locations were selected based on their proximity to potential source areas and previous detections of COPCs. Data from that sampling event are being reviewed and will be shared with the site's working group, CAG and the general public in the coming months. EPA will oversee additional groundwater and soil sampling events this fall.

In total, since 2015, EPA has overseen collection of more than 1,600 samples from groundwater, surface water, porewater, surface soil, subsurface soil, sediment, macroinvertebrates, small mammals and fish. This extensive dataset informs EPA's understanding of the nature and extent of risks to human and ecological health on the site. Through this investigation, COPCs, including arsenic, manganese and dioxins/furans, have been identified in shallow groundwater and soils. These findings are reflected in human and baseline ecological health risk assessments completed in 2020 and will inform the development of cleanup plans in future phases of the Superfund process. To date, EPA has overseen the completion of 13 addenda to the Remedial Investigation Work Plan by the PRPs on the site.

For more information about the site, please visit the Smurfit-Stone Mill Site profile page. Interested members of the community can also attend monthly CAG meetings, which take place at the Frenchtown Rural Fire District at 6 p.m. on the first Thursday of each month.