The Sterling Cleaners Site (Site) is located at 304 W. Wisconsin Avenue in Appleton, Outagamie County, Wisconsin. The building on-site was built as a dry cleaning facility in 1954. The dry cleaning operation has changed owners numerous times since initial construction and is currently operated as Sterling Cleaners. The property is immediately bordered on the west and north by residences. Commercial facilities are located across the street to the east and south.
A fire occurred at the facility in 1998. The building sustained substantial damage as a result of the fire. The Wisconsin Department of Natural Resources (WDNR) was notified of a tetrachloroethylene (PCE) release associated with the fire clean-up at the Site in 1999. Despite over excavation of the soil in the area of the spill, clearance samples indicated high concentrations of PCE remaining in the soil (15,000,000 µg/kg). In August 2008, the current owner of the facility provided WDNR with a Preliminary Soil and Groundwater Investigation that confirmed previously suspected PCE contamination at the Site. The current owner is unable to finance the necessary additional studies or removal action to address the situation. Consequently WDNR requested assistance from US EPA to determine the extent of soil and ground water contamination resulting from historic PCE releases and whether sub-surface vapors are impacting neighboring properties, as well as to conduct a removal action to mitigate the PCE contamination.
In March and August, 2010, U.S. EPA conducted site assessment activities. PCE was detected by U.S. EPA at levels 1,000 times greater than the Preliminary Remediation Goal in soils on Site, 7,500 times greater than the MCL in groundwater, and three times above the action level recommended by the WI Department of Health in the indoor air of neighboring properties.
On September 22, 2010, U.S. EPA initiated a removal action at the Site. U.S. EPA's ERRS contractor (Environmental Restoration) excavated contaminated soils, applied in-situ treatment to the remaining PCE contaminated soils at the Site, and installed a sub-slab depressurization system (SSDS) at an impacted residence. Air sampling conducted at neighboring residences subsequent to the September, 2010 removal action indicated an ambient contribution (in addition to the sub-slab vapor intrusion) of PCE contamination. In August, 2011, U.S. EPA and ERRS conducted an additional action to address the ambient PCE vapors impacting residences. The ventilation system at Sterling Cleaners was modified to redirect PCE vapors thru the roof rather than out the northern side of the building.
Additional performance sampling conducted after the ventilation modifications indicated that the removal action was effective at bringing PCE concentrations at participaing neighboring residences below the action level. All participating residences have been issued No Further Action letters.