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17 December 2004 <br /> AGE-NC Project No 95-0130 <br /> Page 2 of 6 <br /> as `dry', well MW-4 was inaccessible due to a parked car and could not be sampled The ground <br /> water elevation at wells MW-1, MW-2, MW-3 and MW-5 through MW-8, VW-1C, VW-2A and <br /> VW-3A were calculated by subtracting the measured depth to groundwater from the surveyed casing <br /> elevation As-built monitoring well construction details are summarized in Table 1 Ground water <br /> elevations were plotted and contoured on scaled site maps depicting First Zone and Second <br /> Zone ground water elevations (Figures 3 and 4) <br /> After water levels were measured, approximately 0 40 to 19 gallons of ground water (a minimum <br /> of three casing-water volumes per well) were purged from wells MW-1, MW-2, MW-3, MW-5 <br />' through MW-8, VW-1C, VW-2A and VW-3A by lowering and raising a 3/8-inch outer diameter, <br /> length-discrete polyethylene hose equipped with a ball-valve water tip through the specific water- <br /> charged screened section A Watera-Hydro-Lift H pump equipped with a mechanical arm was <br /> I utilized to surge the polyethylene hose Temperature, pH and conductivity were measured for <br /> stabilization at regular purge-volume intervals from each well using the Oakton water analyzer Field <br /> data and logs are in Appendix B Multi-level well purged ground water was transferred to 55-gallon <br />' drums and stored on-site in an area lacking general public access <br />' • 2 2 GROUND WATER SAMPLING <br /> Ground water samples were collected from wells MW-1, MW-2, MW-3, MW-5 through MW-8, <br />' VW-1C, VW-2A and VW-3A utilizing 3/8-inch diameter polyethylene tubing and poured directly <br /> into the 40-m1 EPA-approved volatile organic analysis (VOA) vials containing 0 5 ml 18% <br /> I hydrochloric acid as a sample preservative Care was taken to ensure that visible air bubbles were <br /> not present in the vials after filling and capping Ground water sample containers were labeled with <br /> the well designation, date, time, and sampler's initials <br /> 23 LABORATORY ANALYSIS OF GROUND WATER SAMPLES <br /> Each ground water sample was logged on a chain-of-custody form,placed in a chilled container and <br /> transported to a California Department of Health Services (DHS)-certified laboratory for analysis <br />' for <br /> • Total petroleum hydrocarbons quantified as gasoline(TPH-g)by EPA Method 5030/8015M, <br />' • Benzene, toluene, ethylbenzene and xylene (BTEX), methyl-tertiary butyl ether (MTBE), <br /> 1,2-Dichloroethane (1,2-DCA), ethylene dibromide (EBD), tertiary butanol (TBA), di- <br /> isopropyl ether (DIPE), ethyl tert butyl ether (ETBE), tert amyl methyl ether (TAME) and <br /> MTBE by EPA Method 8260B <br />' Advanced CeoEnvironmental,Inc <br /> 1 <br />