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I 07 August 2001 • AGE-NC Project No 98-0511 Page 2 of 4 2 2 COLLECTION AND LABORATORY ANALYSIS OF GROUND WATER SAMPLES Water samples were collected from each purged well using new disposable plastic bailers Each water sample was transferred Into laboratory-supplied 40-m1 VOA vials containing 0 5 ml 18% hydrochloric acid as a sample preservative After collection, the samples were properly labeled, placed in a chilled container, transported under chain-of-custody to McCambell Analytical ILaboratories, Inc , and were analyzed for • Total petroleum hydrocarbons quantified as gasoline (TPH-g) in accordance with EPA IMethods 5030 and 8015m, • Volatile aromatic hydrocarbons-benzene,toluene,ethylbenzene and total xylenes(BTEX) Iwith methyl tertiary-butyl ether(MTBE) in accordance with EPA Method 60218020, and • Fuel oxygenates di-isopropyl ether (DIPE), ethyl tertiary-butyl ether (ETBE), MTBE, tertiary-amyl methyl ether (TAME) tertiary butanol (TBA), methanol and ethanol in accordance with EPA Method 8260 Modified 3.0. FINDINGS Ground water elevation and flow direction were calculated from field data, hydrocarbon-impact to ground water was inferred from laboratory analysis of the ground water samples I 31 GROUND WATER GRADIENT AND FLOW DIRECTION ' The elevation of ground water in each well was calculated by subtracting the depth to ground water from the surveyed casing elevations (Table 1) Depths to ground water ranged from 13 28 feet to ' 14 07 feet below the tops of the well casings Ground water elevations at the site ranged from 4 05 feet in MW-5 to 4 74 feet in MW-2 relative to mean sea level The ground water is inferred to flow generally toward the northwest, varying from nearly due west to north-northeast, the gradient varies from less than 0 002 ft/ft to 0 006 ft/ft ' 3 2 ANALYTICAL RESULTS OF WATER SAMPLES TPH-g was detected in the ground water samples collected from MW-1 and MW-5 at concentrations ' of 7,300 micrograms per liter (}Lg/1) and 3,500 µg/1 respectively BTEX compounds were detected in MW-1 at concentrations of 230 gg/l benzene,210 gg/1 toluene, ' Advanced GeoEnviranmental,Inc 1