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v <br /> k, 11 June 2002 <br /> �r AGE-NC Project No, 96-0229 <br /> Page 2 of 5 <br /> included with Appendix B.Purged ground water was containerized in 55-gallon drums and was stored <br /> aww on-site in an area lacking general public access. <br /> w, 2.2. GROUND WATER SAMPLING <br /> Following well purging, the ground water level from each well was allowed to achieve a minimum <br /> of 80 percent recharge prior to sample collection except for MW-1, which was purged "dry". Ground <br /> water samples were collected from the purged wells utilizing new, disposable polyethylene bailers, <br /> and transferred to 40-m1 EPA-approved VOA vials containing 0.5 ml 18% hydrochloric acid as a <br /> L• sample preservative. Care was taken to ensure that visible air bubbles were not present in the vials <br /> after filling and capping. Ground water sample containers were labeled with the well designation, <br /> date, time, and sampler's initials. <br /> 2.3. 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 for: <br /> • Total petroleum hydrocarbons quantified as gasoline (TPH-g)by EPA Method 5030/8015M, <br /> +r- 0 Benzene,toluene, ethyl benzene and xylene(BTEX) and methyl-tertiary butyl ether(MTBE) <br /> by EPA Method 8020, and <br /> • Methanol, ethanol, tertiary butanol (TBA), di-isopropyl ether (DIPE), ethyl tert butyl ether <br /> (ETBE), tert amyl methyl ether(TAME) and MTBE by EPA Method 8260. <br /> 3.0. FINDINGS <br /> Ground water elevation, flow direction and gradient were determined from field data collected on <br /> 14 February 2002; the contaminant impact to ground water was quantified from the laboratory data. <br /> LM <br /> 3.1. GROUND WATER ELEVATION AND GRADIENT <br /> During the 14 February 2002 monitoring event, depths to ground water in wells MW-1 through <br /> MW-10B were measured between 28.53 and 30.45 feet below the tops of the well casings (Table 2). <br /> �. Ground water elevations were calculated to be between 17.96 feet(1\4W-5) and 19.45 feet(MW-10B) <br /> below mean sea level (MSL); the ground water elevation increased an average of 0.66 feet between <br /> ar Advanced GeoEnviron mental,Inc. <br /> V <br />