During 1986, the Missouri Department of Natural Resources began testing public water supply wells in the state for volatile organic compounds (VOCs). During this sampling the chlorinated solvent tetrachloroethylene (PCE) was discovered in New Haven’s municipal wells MW1 and MW2.
The site was added to the National Priorities List in December 1, 2000. As a result of numerous investigations, six operable units (OUs) were identified as sources of contamination. The residence for which the removal action is being taken lies within OU4. Soil contamination in OU4 is believed to be the result of a former resident (circa 1960-1970) pouring waste PCE into a “grease trap” in the basement of his home to clean out the trap and kill tree roots in the gray water line that day-lighted at the back (south) end of his property.
As part of the remedial investigation, in July 2017, EPA conducted VI sampling at the residence. The VI sampling detected PCE and trichloroethylene (TCE) in indoor air above levels of health concern. The concentrations of PCE and TCE samples in the basement air were 380 micrograms/cubic meter (µg/m3) and 15 µg/m3, respectively. The main living level of this one-story house had levels of PCE and TCE at 350 µg/m3 and 14 µg/m3, respectively. Sub-slab concentrations of PCE and TCE samples at the residence were 50,000 µg/m3 and 20,000 µg/m3, respectively.
A time critical removal action was taken on March 15, 2018 at the residence to mitigate exposures to the hazardous substances PCE and TCE detected in the residence above concentrations of concern for human health.