K. Singh & Associates, Inc. (KSingh) was retained by Gavin Petro, LLC to manage emergency environmental response due to a break of an underground gasoline supply pipe at their facility.
On August 9, 2015, the Wisconsin Department of Natural Resources (WDNR) was notified that petroleum vapors were present in the residence directly east of the site identified above. Petroleum vapor levels within the residence at 7524 West Medford Avenue were recorded at levels that exceeded lower explosive levels (LELs). The homeowner was subsequently evacuated and electricity shut off to the building due to the explosion hazard. Analytical results indicated that the water beneath the house is contaminated with hydrocarbons associated with gasoline. Free floating product associated with gasoline was noted in the sump crock of the residence. A break in the distribution piping at this gas station was subsequently discovered.
As part of an emergency response, the gas station was shut down while repairs were made to the product piping, a program of vapor mitigation was implemented, free product and contaminated groundwater was pumped from the sump crock, and a vapor monitoring program of the effective residence and surrounding buildings was implemented. A recovery well was installed and additional pumping was instituted to draw contaminated groundwater and free product back to the site. The result of those efforts, plus installation of an air tight sump lid and explosion proof sump pump, were able to successfully restore the building to a non-explosive environment.
A long term environmental restoration program is now ongoing with indoor air sampling and a full scale environmental investigation program, with a planned utility pathway investigation, underway.
The project required significant coordination with the several departments of the City of Milwaukee, and the WDNR.