Source Area Reduction System (SARS)
In 1998, the Air Force installed the SARS downstream of the Outfall Source Area and Building 1432 USTs to reduce a primary source of contaminants contributing to the Main TCE plume. Soil and groundwater in the source area were isolated by a continuous bentonite slurry wall keyed into bedrock. Westerly Creek, a perennial stream that intersects the source area, was isolated by an impermeable liner. Inside the slurry wall boundaries, an extraction system for groundwater and soil vapor was installed. Soil vapor recovered from the containment zone was initially treated by granular activated carbon (GAC) before being discharged to the atmosphere. Groundwater was pumped to the Boundary Area Hydraulic Containment System (BAHCS) for treatment through an air stripper before being reinjected into the alluvial aquifer. The SARS initially removed over 98 pounds of solvent, but removal over time decreased significantly. The extraction well and treatment system was decommissioned by LAC in April 2005. The slurry wall remains intact.