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28 March 2002 • AGE-NC Project No 95-0141 Page 2 of 4 2 2 GROUND WATER SAMPLE COLLECTION A water sample was collected from each well using a new, clean, disposable plastic bailer Immediately upon retrieval, the sample was transferred into three properly labeled 40-m1 EPA- approved VOA vials containing 0 5 mI 18%hydrochloric acid as a sample preservative The samples were logged on a chain-of-custody form,stored in a chilled container and transported under chain-of- custody to McCampbell Analytical Inc (MAI), a California Department of Health Services(DHS)- certified laboratory The ground water samples were analyzed for ' • Total petroleum hydrocarbons quantified as gasoline (TPH-g) in accordance with EPA Method 8015 Modified, • Benzene, toluene, ethylbenzene and total xylenes (BTEX) and methyl tertiary-butyl ether (MTBE) in accordance with EPA Method 8020, and • Oxygenated compounds - di-Isopropyl ether (DIPE), ethyl tertiary-butyl ether (ETBE), MTBE, tertiary-amyl methyl ether (TAME), tertiary butanol (TBA), methanol, ethanol, ethyldibromide (EDB) and 1,2-dichloroethane(1,2-DCA) In accordance with EPA Method 8260 Modified, respectively 3.0. FINDINGS Ground water elevations and flow directions were Inferred from field data Hydrocarbon-Impact to ground water was characterized from laboratory analytical data 3 1 GROUND WATER ELEVATION AND GRADIENT The average ground water elevation of the seven shallow ground water monitoring wells on 12 February 2002 was approximately 11 8 feet below mean sea level (msl), with the average depth of water at 19 5 feet below casing tops The ground water table occurred within the screened Intervals of wells MW-7 and MW-8 but was between 9 30 and 10 79 feet above the screened Intervals in monitoring wells MW-1 through MW-5 Monitoring well MW-6 was designed as a piezometer,with a 5-foot screened Interval set at approximately 40 feet below the water table, since It possibly is monitoring a different hydraulic zone, MW-6 was not used to determine gradient and flow direction Based on data collected during the February 2002 monitoring event, ground water was Inferred to Ibe flowing toward the southeast with a gradient of 0 005 ft/ft east of the former UST area Advanced GeoEnvironmental,Inc