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1 ' 28 July 2004 AGE-NC Project No 99-0645 ' Page 3 of 5 60 feet bsg Soil samples were collected at five foot intervals, generally beginning at 10 feet bsg, or ' where native soil was encountered below back fill A total of 28 soil samples were analyzed Samples from B6'had concentrations ofBTEX compounds Iand MTBE above laboratory reporting limits MTBE ranged from 0 010 milligram per kilogram (mg/kg)to 0 63 mg/kg Maximum concentrations ofBTEX compounds were 0 020 mg/kg benzene, 0 060 mg/kg toluene,0 030 mg/kg ethylbenzene and 0 070 mg/kg xylenes The sample results from ' B7 showed only one sample contaminated, at 30 feet,with 0 49 mg/kg MTBE Samples from MW- 1R had 1 2 mg/kg TPH-g at 40 feet, MTBE was detected at concentrations of 0 43 mg/kg and 1 2 mg/kg at 30 and 40 feet, respectively, TAME was detected at 30 and 40 feet, in concentrations of 0 040 mg/kg and 0 030 mg/kg, respectively I Results from VW 1 A showed TPH-g and TAME at 40 feet with concentrations of 4 6 mg/kg and 0 01 Omg/kg,respectively MTBE was detected from 40 to 60 feet,ranging from 0 030 mg/kg to 4 2 mg/kg Soil from VW3 had MTBE at 30 and 40 feet with concentrations of 0 020 mg/kg and 0 060 Img/kg, respectively Monitoring and vapor extraction wells were completed within the following intervals MW-1 R from I 80 feet to 100 feet bsg,VW 1B from 15 feet to 40 feet bsg,VW1A from 40 feet to 70 feet bsg, VW2 from 15 feet to 40 feet bsg, VW3 from 20 feet to 50 feet bsg IMTBE was detected in the sample collected from well MW-1 at a concentration of 120 µg/1 SVE REMEDIATION FEASIBILITY PROCEDURES Two separate soil vapor extraction pilot tests were conducted on 18 September 2003 and 06 October I2003 On 18 September 2003, the upper sand layer was tested using vapor well VW1B, screened from 15 feet bsg to 40 feet bsg as the extraction well On 06 October 2003, a second pilot test was conducted on the fine-grained deeper impacted areas closest to ground water at the site using vapor Iwell VW1A, screened from 40 feet bsg to 70 feet bsg as the extraction well The pilot tests were initiated at 8 00 am and continued for 8 hours A total of four soil vapor samples were collected Iduring each pilot test Analytical results of soil vapor samples were generally highest in the second sample collected on 18 September Extraction well VW1B results indicated TPH-g was detected in all the soil vapor samples at concentrations ranging froml 1,000 µg/1 to 14,000 gg/l, benzene, toluene, ethylbenzene and xylenes were detected in every sample at concentrations as high as 54 µg/1 benzene, 1,400 gg/l I toluene, 160µg/1 ethylbenzene,990µg/1 xylenes,and MTBE was detected in all the samples ranging from 730 µg/1 to 860 gg/l Toluene and total xylenes were detected in one sample collected from • VW1A on 06 October at a concentration of 0 39 µg/1 and 0 29µg/1, respectively No other analytes Advanced GeoEnvi ron mental I