Groundwater beneath Anderson, Indiana is contaminated with chlorinated volatile organic compounds (VOCs, a class of industrial solvents that evaporate easily and can be harmful to health). The city discovered unsafe levels in three municipal water supply wells in 1992. EPA added the site to the National Priorities List (NPL, the federal Superfund program's roster of the most serious contaminated sites) in September 2018, making it eligible for long-term federal cleanup funding. The source of the contamination has not been identified despite multiple investigations.
The three affected wells feed into a shared treatment plant where water is blended before it reaches residents, so contamination in any single well affects the same population. Since 1999, the city has treated the water with air strippers, devices that remove dissolved contaminants by exposing water to air. This treatment has kept contaminant levels below federal safety limits, though trace contamination has appeared in treated water in some years. EPA is working with the Indiana Department of Environmental Management (IDEM) and local water suppliers to keep drinking water safe. Water suppliers must test frequently and notify consumers quickly if a serious problem occurs.
Formal investigation under the Superfund process started in September 2024. EPA contractors collected groundwater samples at 28 locations near the wellfield through May 2025, screening for VOCs and related properties. Those results will go into a report that guides where permanent monitoring wells are placed, with installation planned for summer 2026. EPA will expand the study area to map the full extent of contamination and search for its source. No cleanup remedy has been selected yet, and construction of any cleanup system has not begun.
Because investigation work is still in early stages, there is not yet enough data to confirm whether human exposure is fully under control or whether contaminated groundwater has stopped spreading. The site is not ready for anticipated reuse. Additional monitoring and study are needed before cleanup goals can be confirmed as met.
Residents can learn who supplies their water by checking their water bill. For drinking water questions, call the City of Anderson Water Department at 765-648-6420, or the after-hours line at 765-648-6444. IDEM's Office of Water Quality can be reached at 317-234-7477, and EPA's Safe Drinking Water Hotline is available at 1-800-426-4791, Monday through Friday from 8 a.m. to 3 p.m.
