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24 December 2001 AGE-NC Project No. 97-0327 Page 2 of 4 prior to sample collection. Ground water samples were collected from the purged wells utilizing disposable polyethylene bailers, 40-m1 EPA-approved VOA vials containing 0.5 ml 18% Ir hydrochloric acid as a sample preservative and one-liter amber bottles without preservative. Care was taken to ensure that visible air bubbles were not present in the vials after filling and capping. ' Ground water sample containers were labeled with the well designation, date, time, and sampler's initials. 2.3. LABORATORY ANALYSIS OF GROUND WATER SAMPLES Each ground water sample was logged on a chain-of-custodyform, laced in a chilled container an p d transported to a California Department of Health Services (DHS)-certified laboratory for analysis ' for: • Total petroleum hydrocarbons quantified as gasoline and diesel (TPH-g and TPH-d, ' respectively) by EPA Method 5030/8015M and LUFT/EPA 8015B, • Benzene,toluene, ethyl benzene and xylene(BTEX)with methyl-tertiary butyl ether(MTBE) lie by EPA Method 8020, and • Ethylene dibromide (EDB), dichloroethane (1,2-DCA), methanol, ethanol, tertiary butanol ' (TBA), di-isopropyl ether (DIPE), ethyl tert butyl ether(ETBE) and tert amyl methyl ether (TAME), and MTBE by EPA Method 8260 Modified. ' 3.0. FINDINGS ' Ground water elevation, flow direction and gradient were determined from field data collected on 21 June 2001; the contaminant impact to ground water was assessed from the laboratory data. 3.1. RELATIVE GROUND WATER ELEVATION AND GRADIENT ' The depths to ground water in wells MW-1, MW-2 and MW-3 were between 51.70 and 53.12 feet below the tops of the well casings; ground water elevations at the site were calculated to be between ' 26.23 feet and 26.28 feet below mean sea level. Ground water elevation at the site decreased an average 1.11-feet between the February 2001 and the June 2001 .. ground water monitoring events. Ground water elevations are depicted in Figure 3. ' Ground water flow direction at the site was inferred to be toward the south-southwest at a gradient of 0.0005 ft/ft or less, or approximately 5 feet per mile (Figure 3). ' Advanced GeoEnvironmental,Inc.