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r: • 01 November 2002 AGE-NC Project No 97-0312 Page 2 of 4 locations The ground water elevation in each well and ground water flow direction for the site were �' determined from the data collected (Table 1) After measuring ground water depths, monitoring wells UST-2 through UST-6 were purged using new disposable plastic bailers Between 2 5 and 8 0 gallons of water were removed from wells UST-2 through UST-6 (a minimum of three casing-water volumes per well) Ground water was purged from near the top of the water column to remove water trapped within the unscreened interval of the well casings Temperature, pH and conductivity of purged water were measured at regular Intervals during purging using an Oakton water analyzer The recorded field data and logs are Included. in Appendix A Purged water was stored on-site in 55-gallon DOT-approved drums pending laboratory analysis In addition, the large on-site domestic well was purged and sampled on 29 August 2002 To purge the large domestic well, a drain valve was opened on the water storage tank and the pump was allowed to cycle on and off for approximately 15 minutes The small domestic well was found to be out of service, the electrical service was disconnected and the distribution piping was truncated and capped • 23 COLLECTION OF GROUND WATER SAMPLES The depth to water in the monitoring wells was re-measured following purging to assure a minimum of 80%recharge prior to sampling Water samples were retrieved from each purged monitoring well using new disposable bailers and an equipment blank was collected from the discharge hose of the 2-inch submersible purge pump following decontamination To sample the domestic wells, a sampling port was opened at the well head and samples were collected from the sampling port while the pump was operating to obtain fresh water samples Each sample was transferred into four laboratory-supplied 40-m1 EPA-approved VOA vials containing 0 5 ml of 18% hydrochloric acid as a sample preservative and into one 1-liter amber bottle without preservative The samples were labeled, placed in a chilled container and transported under chain-of-custody to McCampbell Analytical Inc (MAI), a California Department of Health Services (DHS)-certified analytical laboratory in Pacheco The samples were analyzed for • Total petroleum hydrocarbons quantified as gasoline (TPH-g) and diesel (TPH-d) in accordance with EPA Methods 5030/8015m and 355018015m, respectively, • Benzene, toluene, ethylbenzene and total xylenes (BTEX) and the fuel additives methyl tertiary-butyl ether (MTBE), di-isopropyl ether (DIPE), ethyl tertiary-butyl ether (ETBE), tertiary-amyl methyl ether (TAME) and tertiary-butanol (TBA), 1,2-dibromoethane(EDB) • and 1,2-dichloroethane (1,2-DCA) in accordance with EPA Method 8260B, and Advanced GeoEnvironmental,Inc