ARCHIVED REPORTS_XR0006732 CASE 1

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Results of the soil sampling and analysis indicated that the sod beneath the former USTs and dispensers had not been impacted by significant concentrations of gasoline hydrocarbons However, the soil sample collected from beneath the southwestern dispenser did contain 0 017 milligrams per kilogram (mg/kg) of methyl tertiary butyl ether(MTBE) In addition, at a depth of 8 ' feet beneath the western canopy support, Total Petroleum Hydrocarbons (TPH)-as-gasoline was detected at 350 mg/kg and xylenes were detected at 1 2 mg/kg 12 2 C 3nopy Support Over-Excavation and Waste Management On April 1, 1999, under PHS/EHD observation, Fisch Environmental excavated approximately 100 cubic yards of soil from the vicinity of the former eastern canopy support structure and another 100 cubic yards from the vicinity of the former western canopy support structure Each of the excavations ultimately measured approximately 12 feet by 12 feet by 14 feet deep The excavated soil was stockpiled on asphalt pavement and plastic sheeting on the west side of the ' service station building Once the excavation limits had been reached, Ramage Environmental collected two soil samples from each of the excavations The two soil samples collected from the eastern excavation (E-E- 14 and E-W-13) were taken from a cemented clayey silt interval encountered at approximately 13 N to 14 feet below ground surface (bgs) One of the soil samples collected from the western excavation (W-C-13) was also taken from this cemented clayey silt The second soil sample collected from the western excavation (W-W-9) was taken from the overlying, loose, poorly- graded fine-medium sand Caving sands limited deeper excavation and soil sampling on the west side of the western excavation Results of the soil sampling and analysis indicated that the soil beneath the east side of the former eastern canopy support had been impacted by aged gasoline The soil sample E-E-14 ' contained 3,400 mg/kg of TPH-as-gasoline and 400 mg/kg of xylenes Benzene, toluene, ethylbenzene, oxygenates and total lead were not detected in this soil sample The three other M soil samples collected from the excavations did not contain detectable concentrations of TPH-as- gasoline, benzene, toluene, ethylbenzene, xylenes (BTEX) or oxygenates Total lead was detected in only one of the soil samples at a concentration of 5 1 mg/kg Following excavation and soil sampling, the excavations were backfilled with approximately 200 cubic yards of soil from the UST excavation stockpile Based on earlier, soil stockpile sample results, this soil was deemed suitable for on-site re-use as backfill material During backfilling, the equipment operator compacted the backfill material with the backhoe bucket • 6