The two cooling towers were constructed in 1969 and 1970. The cooling tower superstructures were demolished and removed in late 2013. The Limited soil sampling conducted at the cooling tower basins in 2012 and 2013 indicated PCB contamination lower than 10 ppm around Cooling Tower Basins. To further delineate PCB contamination in soils, a soil sampling program for the basins was proposed in the RI/FS Work Plan Addendum #2. Addendum #2 was approved by DOEE on July 23, 2014. The sampling program proposed in Addendum #2 was conducted in August and September, 2014. Subsequent sampling activities were conducted in February and March, 2015. The resulting data largely supported earlier sampling results, but also identified several areas with higher PCB levels (all <50 PPM). Pepco presented the results of the Addendum #2 in Cooling Tower Basins Soil Removal Action Plan dated July 2015. This Action Plan described the proposed soil remediation (via removal), all soils containing greater than 1 ppm PCBs around and under the Cooling Tower Basins. DOEE approved the Action Plan in July 2015. The Action Plan was implemented concurrently with the concrete basin removal. The removal of the cooling tower basins and adjacent PCB-impacted soils was completed in May 2017.