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Ms. Michelle Le August 21, 2012 Page 2 of 4 is located in an area of mixed commercial/industrial and residential land use. Based on a review of the area using Google Earth, the nearest residences appear to be located one block to the north and south about 400 feet away from the spill area. The Site is still currently used as a road and easement and is part of a road and right-of-way owned by the City of Stockton. PG&E operates the transformers via the right-of-way. In January 2092,_Cardno ERL submitted-a document titled `Results of Soil Assessment- and Work Plan for Soil Removal' to provide the information on the investigation and cleanup work that had been completed up to that date and provided information on the additional cleanup that was being proposed. DISC provided comments on this document in February 2012. Subsequently, Cardno ERI submitted an Amendment to this work plan titled `Amendment to Work Plan for Soil Removal' in April 2012. DTSC provided an approval to this document via e-mail. Additional soil removal activities were completed in April and June of 2012 and in August 2012, the Soil Removal Completion Report was submitted to DTSC for review. Summa of Investigation and Remediation Work The documents listed above indicate that a leak of approximately 1 to 5 gallons of transformer oil containing Total Petroleum Hydrocarbons as mineral oil (TPH mineral oil) and PCBs consisting exclusively of Aroclor 1254 was reported on February 21, 2011. An abatement and removal action subsequently followed which included two rounds of post cleanup sampling. Sample results indicated that the soil left in place in the area of the spill contained between 0.09 milligrams per kilogram (mglkg) and 2.9 mg/kg of aroclor 1254. Following approval of the Amendment to the Work Plan for Soil Removal, additional excavations were conducted in April and June of 2012 resulting in the`remeval ef-appmxImately 62 cubic-yards-of sell. The excavated-soils were-colllec#ed - --not only from the City Right of Way but also from two private property parcels; one owned by the Teichert Company located southwest of the spill site, and the other owned by the Stockton Terminal and Eastern Railroad (STER) property located northwest of the spill area. A total of 30 confirmation samples were collected#ollowing the April and June 2012 remediation efforts. Results from these samples showed that the Tiechert Property had achieved unrestricted land use as concentrations pf PCBs were below the 0.089 mg/kg residential level in this area. Only one confirmation sample within the City Right of Way had PCB concentrations above the residential level. However, at 0.19 mg/kg,this result is below the commercial land use level of 0.3 mg/kg and equates to approximately - 2x10'6 cancer risk under the residential land use scenario; well within the discretionary risk management range of 10-'to 10-4. in addition, the 0.19 mg/kg concentration is below the non-cancer hazard quotient of 1.