Underground Storage Tank Removed

October 1993

An underground storage tank was removed from the area of a 25,000 gallon waste oil-solvent spill in 1977 at the Central Steam Facility, Building 610. Associated piping for the 5,000 gallon tank and visibly contaminated soil were also removed from this area.

To address the volatile and semi-volatile organic compounds (VOCs and SVOCs) remaining in soils and groundwater, an air sparging/soil vapor extraction system was installed and began operating in November 1997. This system stripped the VOCs and SVOCs from soils and groundwater into their vapor phase. The vapors were then extracted from the ground and filtered to remove the contaminants. Monitoring showed that, as of late 2000, levels of VOCs in area groundwater were below the drinking water standard. As a result, the system was shut down in January 2001 and dismantled in 2003. Groundwater monitoring continues.