Windom Dump is an 11-acre former municipal landfill in Windom, Minnesota. It operated starting in the 1930s and accepted industrial and municipal waste, including paint sludges, solvents, and cleaners, between 1957 and 1974. That waste contaminated groundwater with volatile organic compounds (VOCs) and other hazardous chemicals. EPA added the site to the National Priorities List (NPL) in 1986. The NPL is the federal list of the most serious hazardous waste sites in the country.
Eight contaminants of concern have been identified at the site, all within one cleanup unit covering the landfill and groundwater. They include 1,2-dichloroethene, arsenic, benzene, vinyl chloride, dibutyl phthalate, nitrate, tetrachloroethene, and trichloroethene. Most were found in groundwater. Dibutyl phthalate was found in solid waste inside the landfill.
Cleanup actions began after a 1989 remedial action plan was selected. Workers re-graded and capped the landfill, installed groundwater pump-out wells, and added treatment systems to the city's water supply. The City of Windom built a new water treatment plant in 1997. Construction was finished by December 1991. EPA deleted the site from the NPL in October 2000. The Minnesota Pollution Control Agency (MPCA) now oversees the site, and the City of Windom maintains the landfill cap and groundwater pump system, which runs as needed when contaminant levels exceed thresholds. Institutional controls, including a restrictive covenant and zoning restrictions, limit land use and groundwater access. The city owns and maintains the fenced property.
EPA completed its seventh five-year review in March 2025. The review confirmed that the current remedy protects human health and the environment. Human exposure is under control, groundwater contamination is stable in its original area, and no unacceptable discharge to surface water has been found. Testing found no detectable PFAS (per- and polyfluoroalkyl substances) above regulatory levels. However, EPA identified several actions still needed for long-term protection. Those include developing Long-Term Stewardship procedures, repairing a damaged PVC sprayer head component, and continuing to monitor 1,4-Dioxane and PFAS.
Community members with questions can contact the EPA Remedial Project Manager or the Minnesota Pollution Control Agency. Site records are available for public review at the MPCA office at 520 Lafayette Road North, St. Paul, Minnesota.
