The Joslyn Manufacturing and Supply Company site is a 36-acre former wood-treating facility in Brooklyn Center, Minnesota, near Twin Lake. Wood-treating operations ran from the 1920s until 1980, leaving behind spilled hazardous chemicals and buried process sludge. The site was added to the EPA's National Priorities List (NPL) in 1984 because of extensive soil and groundwater contamination.
The main contaminants are pentachlorophenol (PCP), polycyclic aromatic hydrocarbons (PAHs), and chlorinated dioxins and furans. PCP and PAHs show up in groundwater, surface water, soil, and sediment. Dioxins are present in soil in the West Area of the site. These substances pose unacceptable risks to human health through ingestion or direct contact.
The Minnesota Pollution Control Agency (MPCA) leads cleanup. The site is divided into five operable units, each targeting a specific area or type of contamination. Between 1989 and 1998, about 85,000 cubic yards of contaminated soil were treated on-site through biological degradation. Remaining soils were capped with buildings or clean soil. Groundwater pumping, recovery systems, and long-term monitoring have been in place to prevent contaminated water from spreading. Cleanup of the West Area began in late 2022 and finished in November 2024. That work included excavating contaminated soils, hauling them to a permitted landfill, consolidating remaining soils under a clean cap, and restoring wetlands. EPA partially deleted the eastern portions of the site from the NPL in August 2002, and those areas have since been redeveloped for industrial use. As of December 2024, four businesses on-site employ 318 people and generate about $262 million in annual sales.
Physical construction of the cleanup is complete across the entire site. EPA has determined that human exposure is under control and that contaminated groundwater migration is stabilized, with no unacceptable discharge to surface water. However, the site has not yet achieved sitewide readiness for anticipated reuse, meaning cleanup goals have not been fully met across all land uses or required land-use restrictions have not all been put in place. Zoning restrictions and other institutional controls limit uses that could expose people to remaining contamination. Groundwater treatment and monitoring continue.
Community members with questions can contact EPA's Community Involvement Coordinator or Remedial Project Manager. Questions can also be directed to the Minnesota Pollution Control Agency. Public records about Superfund work at the site are available at the MPCA's public information repository at 520 Lafayette Road North in St. Paul, Minnesota.
