PCBS in the Delaware: A thirty-one year technical and legal odyssey

The Metal Bank Superfund Site, located in northeast Philadelphia, has been the subject of study and litigation for the past 31 years. The odyssey began in 1972 when at least 21,000 gallons of PCB-rich transformer fluid leaked from a UST, spilling into the Delaware River. The Delaware River is tidal in the vicinity of the Site. A shallow embayment or mudflat forms the western portion of the Site. It consists of fine silts and clays, with some occasional grav el in the subsurface. The Property itself is composed of urban fill. Groundwater underneath the Site flows into the Delaware River. Depth to groundwater varies from 7'-16' feet. Following the 1972 spill PCB contaminated oil was measured in mudflats soils at levels exceeding 1500 ppm. In 1977 PCB concentrations measured at 1,539 ppm. In 1989 at the termination of a six-year pump and treat operation, the concentrations measured 1540, the same as prior to the remediation. Surface soils at the Property also contained PCBs at concentrations up to 42 ppm; total SVOCs at concentrations up to 2,008 ppm; and lead concentrations up to 27,000 ppm (or 22.7% of the sample). SVOCs and PAHs had high positive correlations with PCBs.