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I ' r 30 September 2005 AGE-NC Project No 95-0184 ' Page 2 of 5 2 2 COLLECTION OF GROUND WATER SAMPLES Water samples were collected from wells MW-2 through MW-4, MW-7, VW-3, and VW-4 with a ' hose bailer,while dedicated disposable plastic bailers were used to sample the remaining wells after allowing the wells to achieve a minimum 80%recovery of the pre-purge water volume Each water sample was transferred into laboratory-supplied, 40-milliliter(ml)volatile organic analysis(VOA) I vials containing 0 5 ml 18% hydrochloric acid solution as a sample preservative, the sample from MW-4 was also transferred into a 1-liter amber bottle without preservative After collection, the samples were properly labeled,placed in a chilled container, and transported under chain of custody to Cal Tech Environmental Laboratories (CTEL), a California Department of Health Services (DHS)-certified analytical laboratory, for analysis The samples were analyzed for ' • Total petroleum hydrocarbons quantified as gasoline (TPH-g) in accordance with EPA Method 8015M, and , ' • Volatile organic compounds (VOCs) benzene, toluene, ethylbenzene, and total xylenes (BTEX) and fuel oxygenates di-isopropyl ether (DIPE), ethyl tertiary-butyl ether (ETBE), methyl tertiary-butyl ether (MTBE), tertiary-amyl methyl ether (TAME), tertiary-butyl alcohol(TBA), 1,2-dibromoethane(EDB),and 1,2-dichloroethane(1,2-DCA)in accordance with EPA Method 8260B Full Scan ' In addition, the ground water sample from well MW-4 was analyzed for total petroleum hydrocarbons quantified as diesel (TPH-d) in accordance with EPA Method 8015M 3.0. FINDINGS ' Ground water elevation and flow direction were inferred from field data Hydrocarbon impact to ground water was quantified by laboratory analysis of the 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) Due to the angle of boring of VW-5, special ' calculations are required to compute the ground water elevation (Appendix C) Depths to ground water ranged from 34 32 feet to 35 02 feet below the tops of the well casings The average ground water elevation at the site was 2189 feet below mean sea level (MSL), indicating an increase of ' 167 feet below MSL between the first quarter 2005 and second quarter 2005 monitoring events The • ground water levels were as high as approximately 20 feet above the screened intervals in wells ' Advanced GeoEnvironmental,Inc r