WORK PLANS - Laserfiche WebLink

Home Browse Search

' • 18 July 2002 AGE-NC Protect No 96-0254 Page 3 of 17 2 4 UST REMOVAL ' AGE was informed that three USTs, dispensers and piping were removed from the site on 31 July f 1991, and that the removal was witnessed by a representative of the EHD, additional information regarding history of the UST use, tank tests,product Inventory and repairs are not known to AGE ' Six soil samples were collected from the sidewalls during the 31 July 1991 excavation, at a depth of five feet below surface grade (bsg), no excavation floor samples were collected because groundwater was encountered in the excavation at a depth of approximately six feet In addition,one ' grab groundwater sample was collected from the excavation and one soil sample was collected beneath the piping/dispenser area The soil and ground water samples were analyzed for TPH-g, BTEX, lead and ethylene dibromide (EDB) ' Concentrations of TPH-g and BTEX compounds were detected in each soil sample collected from the UST excavation TPH-g was detected from the east wall of the UST excavation at a maximum ' concentration of 62 milligrams per kilogram(mg/kg)and from the west wall of the UST excavation at a maximum concentration of 26 mg/kg Benzene was not detected above the elevated detection limits in the soil samples collected from the UST excavation walls Lead was detected at a maximum '• concentration of 10 mg/kg EDB was detected in one sample at a concentration of 2 9 mg/kg TPH-g and BTEX compounds were detected in the water sample at concentrations of I 150,000 micrograms per liter (µg/1) and 25,000 gg/l, 43,000 gg/l, 5,700 µg/1 and 32,000 µg11, respectively Lead was detected at a concentration of 0 67µg/1 in the water sample,however,EDB ' was not detected ' 3.0. ASSESSMENT OF HYDROCARBON-IMPACTED SOIL AND GROUND WATER On 24 June 1997,a total of nine soil probe bonngs(BI through B9)were advanced at the site under EHDoversight Probe bonngs were advanced in the area of the former USTs,and northward towards the property line(Figure 2) Soil inprobebonngsBlthrough B5were continuously sampled(cored), whereas soil in probe boring B6 was sampled at the vadose zone/ground water interface In addition, ' grab ground water samples were collected from BI through B9 The grab ground water samples and selected soil samples were analyzed for TPH-g,TPH-d,BTEX and methyl tert-butyl ether(MTBE), however, soil samples collected from probe boring BI were not analyzed, because field screening ' with a organic vapor monitor (OVM)indicated that the samples were not impacted by petroleum hydrocarbons ' TPH-g was detected in six soil samples collected from four of the probe borings,B2,B3,B4 and B5 TPH-g was detected at concentrations as high as 5,000 mg/kg(B5-6') at depths of • 8 feet bsg or less TPH-g concentrations detected in soil from depths greater than 8 feet bsg ' Advanced GeoEnv ronmental,Inc I