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' 22 July 2003 AGE-NC Project No. 97-0327 ' Page 2 of 4 ' 2.2. GROUND WATER SAMPLING After each well was purged, ground water levels were remeasured to verify the amount of ground ' water recharge. Upon achieving at least 80% ground water recharge, samples were collected from wells MW-I through MW-4 utilizing the techniques described above in purging each well. Ground water samples were transferred into 40-m1 EPA-approved volatile organic analysis (VOA) vials ' containing 0.5 ml 18%hydrochloric acid as a sample preservative and 1-liter amber bottles without sample preservative. Care was taken to ensure that visible air bubbles were not present in the vials j 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-custody form,placed in a chilled container and rtransported to Castle Analytical Laboratory (CAL) of Atwater, a California Department of Health Services (DHS)-certified laboratory. The ground water samples were analyzed for: ' . Total petroleum hydrocarbons quantified as gasoline and d'esel (TPH-g and TPH-d, respectively) by EPA Method 5030/8015 and 8015B; ,a "°yar 1 Benzene, toluene, ethylbenzene, xylene (BTEX)"nethyl-tertiary butyl ether (MTBE) ethylene dibromide (EDB), 1,2-dichloroethane (1,2-DCA), tertiary butanol (TBA), di- isopropyl ether(DIPE),ethyl Cert butyl ether(ETBE)and tert amyl methyl ether(TAME)by ' EPA Method 5030/8260. 3.0. FINDINGS ' Field data was utilized to determine ground water elevation, flow direction and gradient.Petroleum hydrocarbon-impact to ground water was quantified by laboratory analysis. ' 3.1. GROUND WATER ELEVATION AND GRADIENT ' The depths. to .ground-water in. wells MW-1-through MW-4 were measured-between 58.39 and 59.75 feet below the tops of well casings; ground water elevations in wells MW-1 through MW-4 were calculated to be between 32.9 feet (MW-4) and 33.00 feet(MW-3) below mean sea level (Figure 3). Ground water elevation at the site generally increased an average 0.95 feet between the • October 2002 and the June 2003 ground water monitoring events. Ground water flow direction for Advanced GeoEnvironmental,Inc.