The Oak Grove Village Well site sits in Sullivan and Oak Grove Village, Franklin County, Missouri. TCE, a volatile chemical, has contaminated groundwater there, affecting private and public drinking water wells. The site was listed on the National Priorities List in September 2002. It is divided into two operable units. Operable Unit 01 covers the well area in the villages, and Operable Unit 02 addresses the closed Sullivan Landfill and surrounding groundwater. A nearby commercial show cave has also been affected by contamination.
TCE is the primary contaminant of concern. It was found in groundwater and can also get into indoor air through a process called vapor intrusion, where vapors from contaminated soil or groundwater seep into buildings. EPA determined that TCE poses an unacceptable risk to human health and the environment. The main exposure risks come from drinking contaminated water or breathing in TCE vapors indoors.
EPA and the Missouri Department of Natural Resources have taken several steps to protect residents. They provided alternate water supplies to homes served by private wells with unsafe TCE levels and installed air mitigation systems at the show cave. Routine sampling of private and municipal drinking water wells continues. Quarterly vapor intrusion sampling began in 2025 near Ramsey Street in Sullivan. For Operable Unit 01, a record of decision was issued in September 2007, and remedial action ran from September 2008 through September 2010. Operation and maintenance activities under state oversight began in October 2010 and continue today. Operable Unit 02 entered its investigation phase in September 2009 and remains in that stage. EPA has determined that human exposure is currently under control and that groundwater migration is stabilized, but physical construction of the cleanup is not yet complete.
Residents who have whole-house water treatment or sub-slab depressurization systems should keep those systems running. Community members can join the site mailing list to get updates on activities and future participation opportunities. Two types of assistance are available. Technical Assistance Services for Communities provides free, independent expert review of environmental science and EPA actions through an EPA contractor. Technical Assistance Grants offer up to $50,000 to qualified community groups to hire their own technical advisor. Records related to the site are available at the Scenic Regional Library Sullivan Branch at 525 Cumberland Way in Sullivan. Questions can be directed to EPA or Missouri Department of Natural Resources staff assigned to the site.
