EPA Superfund Site

CHEM CENTRAL

MI | EPA ID MID980477079

About this site’s exposure pathways: As of August 2023, there is not sufficient information available to determine the site-wide Human Exposure Control status at the Chem Central Superfund Site because of a newly identified exposure pathway related to the volatilization of volatile organic compounds (VOCs) in the subsurface. The contaminants of concern (COCs) include trichloroethylene (TCE), tetrachloroethylene (PCE) and vinyl chloride in the groundwater. Additional constituents found in groundwater include isopropylbenzene, n-propylbenzene, 1,2,4-trimethylbenzene, and 1,3,5-trimethylbenzene. PCE and TCE degradation byproduct cis-1,2-dichloroethene was detected at concentrations exceeding Maximum Contaminant Level. The sources of the VOCs appear to include contaminated soils and groundwater. The main exposure pathways of concern include the inhalation of contaminated soil gas or sub-slab vapors that become entrained into buildings (vapor intrusion) resulting in the greatest risks at the site. A draft vapor intrusion investigation report was completed by the potentially responsible party (Univar) in 2021. EPA has requested follow-up sampling from some sampling locations in order to determine whether there is a complete vapor intrusion pathway posing an unacceptable risk to human health. Further information was obtained by taking the following actions: collected sub-slab and/or indoor air samples as needed to evaluate the vapor intrusion pathway at select locations and completed a vapor intrusion evaluation to determine whether an unacceptable risk to human health is posed. EPA has the sampling results and an evaluation of the vapor intrusion pathway which are under review. EPA expects to be able to make a determination about the Human Exposure Control status at the Chem Central Site by December 30, 2023.