The Region has approved a CERCLA 104/107/122 settlement under which Stauffer Management Company will perform an RI/FS at the Delaware City PVC Site in New Castle County, Delaware (Site) and reimburse EPA's oversight costs. The Site consists of (1) the parcels of land in located on and near the intersection of Route 13 and Wrangle Hill Road in New Castle County, Delaware, upon which Stauffer Chemical Company (Stauffer) operated a PVC manufacturing plant from approximately 1966 through 1981 and upon which Formosa Plastics Corporation (Formosa) continued manufacturing operations from approximately 1981 through the present (Plant Property); and (2) all locations to which hazardous substances or pollutants and contaminants have migrated from the Plant Property. The Site was listed on the NPL in 1983. EPA issued a ROD in 1986. Stauffer and Formosa implemented remedial action to clean up soils and remediate contaminated groundwater in 1992. Recent investigations have revealed contaminated groundwater beyond the reach of the pump and treat system installed by Stauffer (Site-related contamination is present on the adjacent refinery and in a lower aquifer which was previously believed to not be impacted by the Site). Under the settlement, Stauffer will investigate contaminated groundwater beyond the reach of the existing remediation system.