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UNOCAL Corporation March 9, 1994 Page 3 Petroleum hydrocarbons were detected in some soil samples collected from the product piping trenches These trench areas were overexcavated, and confirming soil samples collected Petroleum hydrocarbons were not detected in the confirming soil samples A second waste oil UST was removed from the eastern portion of the property in May, 1993. Petroleum hydrocarbons were not detected in the soil sample collected from beneath this UST Results of the UST removal investigation were reported in GSI Report No 782701-1 , Tank Removal Observation Report, dated September 11 , 1992 In October, 1993, eight exploratory soil borings (U-A through U-H) were drilled in the locations of the former USTs, the former product dispenser islands, and a hydraulic lift in preparation for site closure During this investigation, Total Petroleum Hydrocarbons calculated as Gasoline (TPH-Gasoline) were detected in four soil samples obtained from borings U-C and U-D These borings were drilled up to 31 5 feet below ground surface (bgs) TPH-Gasoline concentrations ranged from 1 ,600 to 2,900 parts per million (ppm) Benzene was not detected in these samples Results of this subsurface investigation are presented in GSI Report No 782702-3, Exploratory So►l Boring Report, dated December 15, 1992 SCOPE OF WORK The horizontal and vertical extent of hydrocarbon-impacted sods in the southeastern portion of the site remains undefined Groundwater was not encountered during previous subsurface work at this site Additional work in the southeastern portion of the site is warranted to evaluate hydrocarbon impact to soils and groundwater Soil samples collected from beneath the waste oil USTs (UW-1 and UW-2a,b) were analyzed for Cd, Cr (total), Cr (VI), Ni, Pb, and Zn One soil sample from Boring U-A at 16 5 feet bgs was analyzed for WET Ni and WET Pb One soil sample from Boring U-E at 1 '1 .5 feet bgs was analyzed for Cd, Cr (total), Ni, WET Ni, Pb, and Zn Chemical analytical data for these analyses are summarized in Table 1 782790-4 GeoStrategies Inc.