The site is approximately 60 miles southwest of St. Louis, adjacent to the city of Sullivan in Franklin County, along Interstate 44. The legal location of the site is Section 4, Township 40 North, Range 2 West. The total human population within four miles of the site is estimated to be 6,800.
The site is an uncontrolled plume of trichloroethylene (TCE) initially detected in a municipal drinking water well. The Oak Grove Village well drew water from an aquifer that can best be described as karst limestone and dolomite, which are highly soluble and characterized by features such as caves, springs, and solution conduits. Groundwater flow direction at the site is uncertain due to the karst feature throughout the area; the flow is to the northeast, but it could be to the north or to the east. There are over 100 private wells around Oak Grove Village drawing water from the same contaminated aquifer as the municipal well. Two of these are known to have TCE contamination above the maximum contaminant level. Because it is unknown how many other wells are contaminated with TCE at levels of health concern, the MDNR is currently locating and testing private wells for TCE.
MDNR continues to monitor the drinking water at the residences where the filtration systems are in place. MDNR is also working to complete a Record of Decision for the site.
Continue to replace the activated carbon when appropriate.
Completion of the Record of Decision.
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