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18 April 2001 - AGE-NC Project No_ 98-0520 Page 2 of 4 container and transported under chain-of-custody to McCambell Analytical,Inc.(MAI)The samples ' were-analyzed for: • Total petroleum hydrocarbons quantified as gasoline (TPH-g) in accordance with EPA tMethod 5030/8015M; • Volatile aromatic compounds - benzene, toluene, ethyl benzene and xylene (BTEX) with methyl tertiary-butyl ether(MTBE) - in accordance with EPA Method 8020; and ' Fuel oxygenates,Including tertdi-Isopropyllarybutanol(TBA), ether DIPE),ethyl tert-butyl ether (ETBE), tert-amyl methyl ether (TAME), and MTBE, with 1,2-Dichl6roethane (1,2-DCA) in accordance with EPA Method 8260B. After purging and water sampling event at each well the two-stage pump was cleaned in an Alconox ' solution and rinsed prior to preceding to the next well. 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 ground water samples. t .3.1. GROUND WATER ELEVATION AND GRADIENT The relative elevation of groundwater in each well was calculated by subtracting the depth to ground ' water.from the surveyed relative casing elevations-(Table 1). Depths to ground water ranged from 16.95 feet to 17.72 feet below the tops of the well casings.Ground water elevations at the site ranged ' from 19.29 feet (MW-3) to 19.40 feet(MW-4) above mean sea level. The ground water flow direction was determined using ground water elevation data. The ground ` ' water table underlying the site forms a trough-like depressi6n this quarter,with the base of the trough plunging'northwest under an average gradient of 0.0008 ft/ft.The northern limb of the trough flows . west-southwest;the southern limb's flow direction is north-northeast.At such a low gradient,small ' measurement variations can greatly affect the,inferred flow direction. Figure.2 illustrates the contoured ground water elevations as measured on 16 March 2001. 3,2, ANALYTICAL RESULTS OF GROUND WATER SAMPLES, ' TPH-g was detected in all the water samples analyzed at concentrations ranging from' 560 . micrograms per liter (gg/1)in MW-4 to 11,000 µg/1 in MW-5. Advanced GeoEnvironmental,Inc.