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Scope
 BCI was retained by Cendant Car Rental Group to assist with the removal of an Underground Storage Tank (UST) to complete closure activities of an Enterprise Rent-A-Car site as part of an airport parking lot expansion and rental car relocation project at the Gerald R. Ford International Airport.
The Michigan Department of Environmental Quality (MDEQ) was involved during construction activities including the soil excavation from around the building footings and the UST removal (both were completed under the direction of another consultant).
During the footings excavation, impacted soil was encountered. On-site BCI personnel collected initial soil samples confirming impacts. When UST removal activities began, the excavation appeared to be free of a new release during excavation of the overburden fill and while the UST was exposed.
When the excavation site filled with water a sample was collected. Review of the analysis indicated low concentrations of BTEX constituents below generic residential cleanup criteria. Shortly after the water sample was collected, the excavator pierced three holes in the UST, allowing approximately two to four inches of residual fuel that remained in the UST to mix with the excavation water.
A subsequent groundwater sample was collected that showed substantially higher concentrations of gasoline indicator parameters, and free product became visible in the excavation water. A new release was reported with others listed as the Potentially Responsible Party (PRP). The PRP removed the contaminated water from the excavation. Additional soil excavation began from the UST cavity.
BCI performed additional assessment necessary to support a restricted closure and provided the airport a closure report as requested. Closure activities included removal of impacted soils and the UST and remediation system. BCI also performed the completion of a biodegradation evaluation to demonstrate residual contaminant would not migrate beyond a deed- restricted boundary. Site closure was approved by the MDEQ in January 2008.
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