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' 27 April 2004 AGE-NC Project No 98-0511 ' Page 2 of 4 ' 22 COLLECTION AND ANALYSIS OF GROUND WATER SAMPLES Water samples were collected from each purged well using a new, dedicated disposable plastic ' bailer Each water sample was transferred into Iaboratory-supplied 40-m1 volatile organic analysis (VOA)vials containing 0 5 ml 18%hydrochloric acid as a sample preservative After collection,the samples were properly labeled, placed in a chilled container, transported under chain-of-custody to ' McCampbell Analytical, Inc (MAI), a California Department of Health Services (DHS)-certified laboratory, and were analyzed for • Total petroleum hydrocarbons quantified as gasoline (TPH-g) in accordance with EPA Method 5030/8015M, I • Benzene, toluene, ethylbenzene and total xylenes(BTEX) in accordance with EPA Method 8021B, and • Fuel additives, including methyl tertiary-butyl ether (MTBE), tertiary butanol (TBA), di- isopropyl ether (DIPE), ethyl tertiary-butyl ether (ETBE), tertiary-amyl methyl ether (TAME), 1,2-dibromoethane(EDB) and 1,2-dichloroethane (1,2-DCA) in accordance with lieEPA Method 8260B 3.0. FINDINGS Ground water elevation and flow direction were determined from field data Hydrocarbon-impact to ground water was inferred from laboratory analysis of ground water samples 3 1 GROUND WATER GRADIENT AND FLOW DIRECTION The elevation of ground water in each well was calculated by subtracting the depth to ground water from the surveyed casing elevation (Table 1) Depths to ground water ranged from 16 02 feet to 17 09 feet below the tops of the well casings Ground water elevations at the site ranged from 1 14 feet above mean sea level (MSL) in MW-7 to 1 53 feet below MSL in MW-4 Ground water at the site was inferred to flow generally toward the southwest(Figure 3)with an hydraulic gradient of approximately 0 002 ft/ft Advanced GcoEnvironmental,Inc