In 1982, Formosa reported discharges of 1,2-dichloroethane (1,2 DCA or EDC) to the former wastewater treatment plant area and releases of EDC to the soil and groundwater in the PVC production area. EPA issued the existing 3008(h) in 1991 and required Formosa to conduct corrective actions, including a RCRA Facility Investigation, a Corrective Measures Study, and Corrective Measures Implementation according to a specific schedule. In 1993, Formosa reported a discharge of EDC when a tank collapsed in the Chlor Alkali Plant. Surface soils were removed, and a pump and treat system was emplaced to remediate contamination in saturated soils and groundwater.