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I 07 May 1999 • AGE-NC Protect No 95-0104 Page 4 of 8 collected in Tedlar bags using an organic vapor analyzer as an air pump Following sample collection, the samples were placed in a covered container and transported under cham-of custody to McCampbell Analytical Inc (MAI) in Pacheco, California Each sample was analyzed within 72 hours for TPH-g and BTE&X in accordance with EPA Methods 8015m and 8020, respectively 4.0. FINDINGS ' From ground water monitoring data,AGE was able to determine the ground water flow direction and gradient Laboratory analysis detected fuel hydrocarbons in one ground water sample (MW-5), Itoluene and xylenes were detected in one ground water sample (MW-4) From field data collected dunng operation of the SVE/IAS pilot test and from laboratory analysis I of four soil gas samples,AGE was able to estimate the volume of vapor gasoline extracted from well VW-1 lie 4 1 RELATIVE GROUND WATER ELEVATION AND GRADIENT During the April 1999 morutonng event, depths to ground water in wells MW-1 through MW-6 and VW-1 were measured between 52 57 and 53 35 feet below the tops of well casings, between the I January and April 1999 ground water monitoring events, ground water elevation at the site increased an average 5 29 feet The ground water elevation data for MW-1 through MW-6 and VW-1 during the April 1999 ground water monitoring event is depicted in Figure 3 and shown on Table 1 Ground water flow direction in the area of MW-1 through MW-6 was generally toward the northeast at a gradient of 0 003 ft/ft, or approximately 15 feet per mile (Figure 3) Ground water was Iapproximately 27 feet above the screen intervals at MW-2, MW-3 and MW4 and between 10 and 14 feet above the screen intervals at MW-5 and MW-6 Therefore these wells are "drowned", and yield samples more representative of deeper ground water than of shallow ground water, which is commonly the more intensely impacted by petroleum hydrocarbons Monitoring well MW-1 and vapor extraction well VW-1 are screened across the top of the saturated zone 4 2 ANALYTICAL RESULTS OF GROUND WATER SAMPLES A total of six ground water samples were submitted to a DHS-certified laboratory in April 1999 • TPH-g was detected in a water sample collected from well MW-5 at a concentration of 120 micrograms per liter(µg/1), Advanced GeoEnvironmenial,Inc.