EPA Superfund site

ACM SMELTER AND REFINERY

Human exposure is NOT currently under control

  • MT
  • EPA ID MTD093291599
  • EPA exposure status as of November 10, 2026

Data limitations: Proximity to a Superfund site boundary does not mean your property is contaminated. EPA site boundaries show the area designated for cleanup, not the full extent of contamination. Groundwater plumes can extend beyond site boundaries. This tool shows publicly available EPA federal data. It is not affiliated with or endorsed by EPA, and is not a substitute for a professional environmental assessment.

About this site's exposure pathways

As of August 2026, the ACM Smelter and Refinery Superfund site is considered Current Human Exposure Not Under Control (HENC). Residential soils and railbed material within Operable Unit 01 - Community Soils currently expose residents to arsenic and lead. These exposure pathways are considered unacceptable based on EPA risk-based criteria. Remedial investigation for Operable Unit (OU) 2, which encompasses the former smelter area and adjacent areas, is underway.

Currently, EPA plans to address this pathway by removing lead- and arsenic-contaminated soils above risk-based action levels and replacing them with clean fill. If you are impacted by risks inherent at this site, the latest fact sheet includes recommendations for reducing exposure including: wipe shoes on doormat or remove shoes while in the home; don’t eat food, chew gum, or smoke when working in the yard; wash childrens hands and feet after they have been playing outside; wash childrens toys regularly; wash dogs regularly; damp mop floors and damp dust counters and furniture regularly; and wash and peel all fruits, vegetables, and root crops from residential gardens. Yard cleanups to address lead- and arsenic-affected soils in the community of Black Eagle have begun as of May 6, 2024.

To address immediate threats to human health and the environment, EPA removed approximately 1,200 cubic yards of contaminated soil from the Moose Lodge property in Black Eagle in November 2011. From September through November of 2020, EPA conducted second time-critical removal of approximately 3,200 cubic yards of soils contaminated with lead and arsenic in advance of a Black Eagle Water and Sewer Districts construction project to replace aging water and sewer lines. For residential soils remedial action is ongoing and over 160 yards have been remediated. Consent Decree negotiations with Atlantic Richfield are underway for cleanup of the OU1 railroad corridor. EPA anticipates that human exposure will be under control in December 2035 when remedial action at OU2 is projected to be complete. Fact sheets advising residents on how to reduce exposure with potential contaminants in the community were distributed and the current fact sheet includes recommendations for reducing exposure.

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