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28 January 2005 AGE-NC Project No 96-0232 Page 4 of 8 2 6 MONITORING WELL DEVELOPMENT On 07 December 2004,the dual ground water monitoring wells MW-20A and-20B were developed utilizing a 2-inch diameter, stainless steel hand bailer and a Watera-Hydra-Lift 11 pump equipped with a mechanical arm and 3/a-inch diameter polyethylene hosing to surge and remove any remaining sediment that had accumulated at the bottom of each well Ground water was purged from each monitoring well until ground water was visually sediment free, approximately 17 gallons of water were removed from well MW-20A and 56 gallons of water removed from well MW-20B Purge water generated during monitoring-well development was transferred to the Flag City Chevron ground water remediation system holding tank for treatment and disposal Following well development, ground water samples were collected from the purged wells MW-20A and MW-20B utilizing new,2-inch diameter disposable polyethylene bailers Groundwater samples were transferred into one-liter amber bottles without a preservative and into 40-m1 EPA-approved volatile organic analysis (VOA) vials containing 0 5 ml 18% hydrochloric acid as a sample preservative Care was taken to ensure that visible air bubbles were not present in the vials after filling and capping Ground water sample containers were labeled with the well designation, date, time,and sampler's initials Subsequently,each preserved sample was logged on a chain-of-custody form, placed in a chilled container and transported to CTEL for analysis for • TPH-g, TPH-d an TPH-mo by EPA Method 5030/8015M, and • BTEX, 1,2-DCA, EDB, TBA, DIPE, ETBE, TAME and MTBE by EPA Method 826013, 2 7 SURVEYING OF GROUND WATER MONITORING WELLS On 12 January 2005, a state of California state-licensed survey engineer from Baumbach&Piazza, Inc (BPI) surveyed reference points on the top of the dual well casings from well MW-20 to the nearest 0 01-foot relative to known National Geodic Survey Datum No C464 (NAVD88) Additionally, BPI utilized global positioning system (GPS) techniques to identify latitude and longitude for tracking well MW-20 on the State Water Resources Control Board (SWRCB) GeoTracker database system The results of the monitoring well survey are contained in Table 4 The surveying report (BPI Job No 97-0249) is presented in Appendix F 3.0. FINDINGS Soil boring and monitoring well installation soil descriptions were utilized to construct geologic cross section E-E'off the site, field data was utilized to select soil samples for laboratory analysis Advanced GeoEnvironmental,Inc