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14 January 2004 . AGE-NC Project No.,98=0520 Page 2 of 4 properly labeled, placed in a chilled container and transported under chain-of-custody to Cal Tech ' Environmental Laboratories (CTEL), a, California Department of Health Services,(DHS)-certified analytical laboratory, for analysis. The samples were analyzed for: ' Total petroleum hydrocarbons quantified as gasoline (TPH-g) in accordance with EPA , Method 8015M; and ' Benzene, toluene, ethyl benzene and xylene (BTEX),and fuel additives, including methyl tertiary- butyl,ether(MTBE), tertiary butanol (TBA), di-isopropyl ether (DIPE), ethyl tert- butyl ether (ETBE), tert-amyl methyl ether (TAME), 1,2-dichloroethane (1,2-DCA) and 1,2-dibromoethane (EDB) in accordance with EPA Method 8260B. 3.0. FINDINGS Ground water elevation and,flow direction were determined from field.data collected on 27 August 2003. Hydrocarbon-impact to ground water was quantified from laboratory analysis of the ground•. water samples. ; 3.L GROUND WATER ELEVATION AND GRADIENT ' 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 23.75 feet ' (MW-7) to 24.95 feet {MW-6) below the tops of the well casings (btoc). Ground water elevations at the site (not including MW-6) averaged approximately 12.21 feet above mean sea level (MSL) showing an elevation decrease of approximately 2.11 feet since the last monitoring event. The ground water flow direction was determined using ground water elevation data from water table wells MW-3 through MW-5 and MW-7 through MW-10. Elevation data from well MW-6was not - utilized because well MW-6 is a deep-screen well. The groundwater table underlying the'site forms anorthwest trending trough wh ich flows into a slight depression northwest of the site;the net ground water flow is toward the northwest under an average gradient of 0.002 foot/foot. Figure 3 illustrates ' the contoured ground water elevations as measured on 27 August 2003. ' 3.2. ANALYTICAL RESULTS OF GROUND WATER SAMPLES ; ' TPH-g was detected in the water samples collected from wells MW-3 and-MW-5, at concentrations of 870 micrograms per liter(erg/l) and 1,000 lrg/l, respectively.Figure 4 illustrates the approximate distribution of dissolved TPH-g. ' Advanced CeoEnvironmental,Inc.