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11 March 2002 i AGE-NC Project No 95-0130 Page 2 of 13 2 2 UNDERGROUND STORAGE TANK REMOVAL One 550-gallon UST and two 4,000-gallon gasoline USTs,dispensers and product piping were removed from a east section of the site (former UST area No 1) on 01 September 1998 Soil samples were collected beneath the former USTs and product piping areas Total petroleum hydrocarbons quantified as gasoline (TPH-g) was detected in soil samples collected beneath the east and west sections of the former 4,000-gallon UST excavation area at concentrations as high as 8,200 mg/kg, benzene,toluene, ethylbenzene and xylene (BTEX)constituents were detected at concentrations as high as 1,400 mg/kg The greatest benzene concentration was I detected at a concentration of 6 3 mg/kg Methyl tert butyl ether (MTBE) was detected from the same samples at concentrations as high as 13 mg/kg, tert-amyl methyl ether (TAME)was detected at concentrations as high as 0 29 mg/kg and tert butanol (TBA) was detected at concentrations as high as 5 1 mg/kg Total lead was detected in samples at concentrations as high as 32 mg/kg No other analytes were detected above laboratory reporting limits from the analyzed samples Analytical results of soil samples collected during UST removal activities are summarized in Table 1 It is AGE's understanding that two USTs were removed from a southeast section of the site(former . UST area No 2) circa 1988 Soil samples collected beneath each UST and beneath the associated piping The samples were analyzed for total petroleum hydrocarbons quantified as gasoline(TPH-g) and benzene, toluene, ethylbenzene and xylene (BTEX) constituents TPH-g and BTEX were detected in the soil samples collected beneath the USTs at concentrations ranging from 22 milligrams per kilogram (mg/kg) to 2,200 mg/kg 2 3 PREVIOUS SUBSURFACE INVESTIGATION The following is a summary of previous investigations at the site of the unauthorized release of fuel products to the subsurface • December 1994 - Five soil borings (B-1 through B-5) were advanced at the site near the former UST areas Soil bonngs B-1, B-3 and B-5 were advanced to depths of 35 feet, B-2 and B-4 were advanced to depths of 65 feet Petroleum hydrocarbon impacted soil was encountered in all five soil borings at depths between 10 feet and 65 feet (Table 1) Results of the December 1994 investigation were reported in Preliminary Investigation and Evaluation Report(PIER),dated 10 April 1995,prepared by Geological Audit Services,Inc • January 1995 -Four soil borings(MW-1,MW-2,MW-3 and B-6)were advanced at the site as part of the ongoing investigation Soil boring B-6 was advanced to a depth of 65 feet, MW-1, MW-2 and MW-3 were advanced to depths of 80 feet and completed as ground water monitoring wells Petroleum hydrocarbon impacted soil was encountered in all four Isoil borings at depths between 35 feet and 65 feet Dissolved TPH-g and BTEX compounds Advanced GeoEnvironmental,Inc