ARCHIVED REPORTS_XR0006749 CASE 1

Home Browse Search

r ' Results of the soil sampling and analysis indicate that the soil 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 ternary butyl ether (MTBE) 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 1 2 2 Canopy Support Over-Excavation and Soil Sampling ' 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 sod samples from each of the excavations The two sod 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 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 sod sampling on the west side of the western excavation Results of the soil sampling and analysis indicate that the soil beneath the east side of the former ' eastern canopy support had been impacted by aged gasoline (Table 1) 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 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 This lead concentration probably represents background conditions Following excavation and sod sampling, the excavations were backfilled with approximately 200 cubic yards of soil from the UST excavation stockpile Based on earlier, soil stockpile sample r 6 r r