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1 ' 27 October 2004 • AGE-NC Project No 96-0254 ' Page 3 of 10 presented in Table 2, The analytical result of the grab ground water sample collected is presented in Table 3 ' 2 4 ASSESSMENT OF HYDROCARBON-IMPACTED SOIL AND GROUND WATER ' On 03 December 1998, six soil probe bonngs (B 1 through B6) were advanced at the site to assess the lateral and vertical extent of petroleum-impacted soil(Figure 2), in addition,grab ground water samples were collected from bonngs B 1 and B6 TPH-d,benzene,toluene,ethylbenzene and xylenes (BTEX)and oxygenated fuel additives were not detected in any of the soil boring samples analyzed TPH-d and BTEX compounds were not detected in any of the water samples analyzed from boring B1 and B6, but the oxygenated fuel additive methyl-tertiary butyl ether (MTBE) was detected at t concentrations as high as 760 micrograms per liter (µg/1), no other fuel additives were detected in the analysis of the water samples 'Analytical results of soil samples are presented in Table 2 Analytical results of the grab ground water samples collected during the December 1998 ' investigation are presented in Table 3 On 12 and 13 January 2000,monitoring wells MW-1 through MW-4 were installed at the site Total ' petroleum hydrocarbons as gasoline(TPH-g),TPH-d and BTEX were not detected above laboratory reporting limits In the nine soil samples analyzed from pilot soil borings MWA,MW-2 and MW-3 ' (soil samples were not collected from boring MW-4) However,MTBE was detected in eight of the nine soil samples at concentrations ranging from 110 micrograms per kilogram (µg/kg) to 2,580 µg/kg (MW1-20) Analytical results of soil samples collected from the January 2000 well ' installations are presented in Table 2 The Initial monitoring of wells MW-1 through MW-4 was conducted on 19 January 2000 TPH-g, ' TPH-d and BTEX compounds were not detected in the analyzed samples However, MTBE was detected in ground water samples MW-1,MW-2 and MW-3,concentrations of MTBE ranged from 200 micrograms per liter(µg/1)to 9,800µg/1 Additional analytical results of ground water sampling ' between January 2000 and July 200A are presented in Table 4 and Table 5 On 12 October 2000,three soil probe boric gs(B7 through B9)were advanced at the site The borings ' were advanced to a depth of 50 feet bsg Soil samples were collected at 5-foot intervals,beginning at a depth of 30 feet bsg''Laboratory analysis detected MTBE in four soil samples at concentrations ranging between 5 1 µg/kg and 52 gg/kg(Table 2),the highest concentration was detected at 30 feet ' bsg in the area of well MW-1 Previous soil sample indicated much greater concentrations of adsorbed MTBE,however the later concentrations appear more accurate towards the site conditions The highest dissolved MTBE concentrations In groundwater were detected In the deep grab ground ' water sample collected at 50 feet bsg in boring B8, at a concentration of 29 µg/l (Table 3), MTBE . was not detected In the other grab ground water samples 1 Advanced GeoEnvwon mental,Inc 1