In 1981, the City of Charlevoix , MI was notified by the Michigan Department of Public Health (MDPH) that its water system was contaminated following routine sampling of the City’s chlorinated water supply. Groundwater was found to be contaminated with trichloroethylene (TCE) and tetrachloroethylene (PCE) that was impacting the municipal water supply. In 1985, U.S. EPA constructed a new water intake system and filtration plant, using water from Lake Michigan as its source.
In 2011, U.S. EPA concluded that PCE contamination that remained in the soil and groundwater could potentially pose vapor intrusion risks via the indoor air pathway and that groundwater may take longer to return to a useable state than had previously been determined. Additional evaluation of the source was determined to be necessary to evaluate the potential for vapor intrusion.
U.S. EPA completed a soil gas, soil and groundwater assessment in August 2012. Follow-up sampling of soil, soil gas, sub-slab soil gas and indoor air was conducted during multiple mobilizations from June 10, 2013, through April 29, 2014. Sample results suggested potential vapor intrusion concerns in former known source areas of the site.
U.S. EPA Region V Field Services personnel conducted a geophysical investigation and identified the presence of underground storage tanks (UST) within the study area in December 2013.
In the summer of 2014, EPA's R5 remedial Project Manager (RPM) Matthew Ohl requested assitance from the R5 Emergency Response Branch to conduct a removal action at the Charlevoix Municipal Well Superfund Site (site) to mitigate threats to public health, welfare and the environment posed by the presence of uncontrolled hazardous substances at the site.
The following planned action is or will be occurring at the site: evaluate and remove on-site UST; delineate extent of soil gas impact and conduct additional vapor intrusion assessment activities (which include installation and sampling of 43 coupled sub-slab soil gas and indoor air locations; and installation of SSD systems at 11 locations based on past assessment results.
As of August 2015, 3 USTs were closed in place, 45 residences have been sampled for vapor intrusion (sub-slab and indoor air), and 16 SSD systems have been installed.
