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• 04 October 2001 AGE-NC Project No 95-0109 Page 2 of 4 2 2 COLLECTION OF GROUND WATER SAMPLES The depth to water was remeasured after purging to ensure a minimum of 80 per cent recharge of the initial water level in each well prior to sampling Water samples were collected from each purged well using disposable plastic bailers Immediately-upon retrieval, the samples were transferred into 40-ml EPA-approved VOA vials containing 0 5ml 18%hydrochloric acid as a sample preservative The samples were labeled, stored on ice, and transported in a clulled container, under chain-of custody,to McCampbell Analytical,Inc. (MAI),a State of CaliforruaDepartment ofHealth Services (DHS)-certified analytical laboratory All samples were analyzed for • Total petroleum hydrocarbons quantified as gasoline (TPH-g) in accordance with EPA Methods 5030/8015M, • Volatile aromatic compounds - benzene, toluene, ethylbenzene and xylenes (BTEX) and methyl tertiary-butyl ether(MTBE) in accordance with EPA method 80201602, • Fuel additives - di-isopropyl ether (DIPE), ethyl tertiary-butyl ether (ETBE), MTBE, . tertiary-amyl methyl ether(TAME), tertiary butanol(TBA),ethylene dibromide(EDB) and 1,2-dichloroethane (1,2-DCA) in accordance with EPA Method 8260M 3.0. FUNDINGS Ground water elevation and flow direction were inferred from field data collected on 17 September 2001 The hydrocarbon-impact to ground water was assessed by laboratory analysis of the ground water samples 3 1 GROUND WATER GRADIENT AND DIRECTION The elevation of ground water in each well was calculated by subtracting the depth to ground water from the surveyed well casing elevations(Table 1) The depth to ground water ranged from 52.30 feet to 57 27 feet below the tops of the well casings Ground water elevations at the site ranged from 3 91 feet below mean sea level (MSL) in well MW-13 to 0 31 feet below MSL in well MW-5 Ground water elevations at the site decreased an average of 1 52 feet between the June 2001 and September 2001 sampling events Ground water levels were within the screened intervals of all the wells sampled Advanced GeoEnwronmental,Inc