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 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 of contamination resulting from the mill's operations.
In 2023, stakeholders and Missoula County requested that EPA consider additional groundwater and soil sampling to address 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 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 used in industrial applications 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 investigate geochemical conditions controlling manganese and arsenic migration through groundwater to Clark Fork River. This sampling will also help understand 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 progress made over the past year with our site partners at 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 ten new groundwater monitoring wells and sampled a total of 58 groundwater monitoring wells for 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 for contaminants of potential concern (COPCs). Samples were also collected from native soils underlying these areas to determine if COPCs are migrating through soil.
These sampling events follow a fall 2023 groundwater sampling event where 33 groundwater monitoring wells were sampled for similar COPCs. Data from that event are being reviewed and will be shared with stakeholders soon. Additional groundwater and soil sampling events are planned for this fall.
Since 2015, EPA has overseen collection of more than 1,600 samples from various environmental media at this site. This dataset informs EPA’s understanding of risks to human health and ecology on-site. Identified COPCs include arsenic, manganese, dioxins/furans found in shallow groundwater and soils; these findings will inform future cleanup plans under CERCLA guidelines.
For more information about this ongoing project or monthly Community Advisory Group meetings held at Frenchtown Rural Fire District on first Thursdays each month at 6 p.m., please visit Smurfit-Stone Mill Site profile page on EPA’s website.
