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14 July 2005 . AGE-NC Protect No 00-0696 IPage 2 of 4 Temperature, pH, and conductivity of the purged water were measured at regular Intervals for stabilization using an Oakton water analyzer Field sheets and data are provided in Appendix C Purged water was containerized in properly labeled,Department of Transportation(DOT)-approved 55-gallon drums and stored on-site pending proper disposal 23 COLLECTION AND ANALYSIS OF GROUND WATER SAMPLES Ground water samples were collected from each monitoring well using the disposable bailers after allowing the wells to achieve a minimum 80%recovery of the pre-purge water volume Each water sample was transferred into three laboratory-supplied, 40-milliliter (ml) volatile organic analysis (VOA) vials containing 0 5 ml 18% hydrochloric acid solution as a sample preservative, and one 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 State of California Department of Health Services(DHS)-certified analytical Ilaboratory, for analysis The samples were analyzed for . - Total petroleum hydrocarbons quantified as gasoline and diesel (TPH-g and TPH-d, ' respectively) in accordance with EPA Method 8015M, and Benzene,toluene,ethylbenzene,and total xylenes(BTEX)and fuel additives methyl tertiary- butyl ether(MTBE), tertiary-butyl alcohol (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 EPA Method 8260B I 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 of the monitoring wells was calculated by subtracting the depths to ground water from the surveyed relative casing elevations (Table 1) Depths to ground water ranged from 4 92 feet(MW-4)to 5 93 feet(MW-1)below the tops of the well casings Ground water elevation at the site ranged from 17 68 feet (MW-4) to 17 81 feet (MW-3) below mean sea Ievel (MSL), and averaged approximately 17 73 feet below MSL, indicating a decrease in ground water elevation of approximately 0 92 feet since the last monitoring event in February 2004 EAdvanced GeoEnvironmental,Inc I