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r08 January 2002 AGE-NC Project No 98-0511 IPage 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 acrd as a sample preservative After collection, the samples were properly labeled, placed in a chilled container, transported under chain-of-custody to McCambell Analytical Laboratories, Inc , and were analyzed for • Total petroleum hydrocarbons quantified as gasoline (TPH-g) in accordance with EPA Methods 5030 and 8015m, • Benzene, toluene, ethylbenzene and total xylenes (BTEX) with methyl tertiary-butyl ether (MTBE) in accordance with EPA Method 602/8020, 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 I 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 3 1 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 16 45 feet to 17 43 feet below the tops of the well casings Ground water elevations at the site ranged from ' 0 96 feet in MW-5 to 1 07 feet in MW-2 relative to mean sea level The ground water at the site was inferred to flow generally toward the northwest,varying from nearly due west to north-northeast,the gradient was very low and varied from approximately 0 0001 ft/ft to 0 0009 ft/ft South of the site (across L Street) the ground water flowed toward the southwest at a gradient of 0 0005 ft/ft 32 ANALYTICAL RESULTS OF WATER SAMPLES I TPH-g was detected in the groundwater samples collected from MW-1 and MW-5 at concentrations of 780 micrograms per liter(µg/1) and 1,200 pg/1 respectively Advanced GeoEnvironmental,Inc