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• • Site Background Information: Comfort Air, Inc. AGE-NC Project No. 95-0141 Page 3 of 5 constituents of concern; no analytes were detected at or above laboratory detection limits in the samples analyzed. On 18 July 2007,an additional ground water extraction well,EX-2,screened from 15 to 35 feet bsg was installed at the site. A total of five soil samples were analyzed for constituents of concern. TPH-g and BTEX compounds were detected in sample EX2-30 at concentrations of 11 mg/kg TPH- g,0.015 mg/kg ethylbenzene and 0.019 mg/kg xylenes.TPH-g and BTEX compounds were detected in sample EX2-35 at concentrations of 22 mg/kg TPH-g,0.22 mg/kg benzene,0.054 mg/kg toluene, 0.42 mg/kg ethylbenzene, and 0.69 mg/kg xylenes. Well Destructions On 22 and 23 October 2002 monitoring wells MW-1,MW-2 and MW-4 were destroyed by utilizing hollow stem augers to drill out the wells to total depths.Subsequently,each borehole was completely backfilled with a portland cement grout mixture to one to two feet below surface grade and the remaining areas were backfilled to surface with neat cement. Cone Penetrometer Test(CPT)Boring Advancements On 10 October 2002,a soil boring(CPT-01)was advanced vertically at the former UST location to a total depth of approximately 147 feet bsg. One soil sample(CPTI-85)and two grab ground water samples(CPTI-96-100 and CPT I-113-117)were analyzed.TPH-g,toluene,ethylbenzene,and total xylenes were detected in soil sample CPTI-85 at concentrations of 1.6 mg/kg, 16 µg/kg, 5.1 µg/kg and 24 µg/kg, respectively;benzene was not detected in the soil sample. TPH-g was detected in grab ground water samples CPT1-96-100 and CPTI-113-117 at concentrations of 13,000 µg/1 and 140,000 µg/l,respectively. BTEX compounds were detected in both samples at concentrations as high as 4,600 µg/1 benzene, 16,000 µg/1 toluene, 2,100 µg/1 ethylbenzene and 11,000 µg/1 total xylenes(CPTI-113-117).In addition, 1,2-DCA was detected in both samples at concentrations of 8.8 µg/l (96 to 100 feet bsg) and 250 µg/1 (113 to 117 feet bsg); EDB was detected in sample CPTI-113-117 at a concentration of 90 µg/1. HYDROGEOLOGIC MODEL Based on the CPT results,supplemented by soil stratigraphic data,AGE has developed apreliminary subsurface model of the site hydrostratigraphy comprised of six informal zones, a vadose (unsaturated) zone and five hydrological units. Hydrological units may be defined as significant Advanced GeoEnvironmental,Inc.