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i' <br /> 27 June 2003 <br /> AGE-NC Project No. 97-0327 <br />' Page 2 of 5 <br /> ' 2.2. Ground Water Sampling <br /> After each well was purged, ground water levels were remeasured to verify the amount of ground <br /> ' water recharge. Upon achieving at least 80% ground water recharge, samples were collected from <br /> wells MW-1 through MW-4 utilizing the techniques described above in purging each well. Ground <br /> water samples were transferred into 40-m1 EPA-approved volatile organic analysis (VOA) vials <br /> ' containing 0.5 ml 18%hydrochloric acid as a sample preservative and 1-liter amber bottles without <br /> 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; The ground <br /> water samples were analyzed for: Y <br /> ojb <br /> ' • Total petroleum hydrocarbons quantified as gasoline .axil-4eso,(TPH-g end-T-PHQ_ <br /> respectively) by EPA Method 5030/8015 and 8015B; <br /> ' • Benzene, toluene, ethylbenzene, xylene (BTEX), methyl-tertiary butyl ether (MTBE) <br /> ethylene dibromide (EDB), 1,2-dichloro ethane (1,2-DCA), tertiary butanol (TBA), di- <br /> isopropyl ether(DTPE), ethyl tert butyl ether(ETBE)and tert amyl methyl ether(TAME)by <br /> ' EPA Method 503018260. <br /> ' 3.0. FINDINGS <br /> ' Field data was utilized to determine ground water elevation, flow direction and gradient. Petroleum <br /> hydrocarbon-impact to ground water was quantified by laboratory analysis. <br /> ' 3.1. GROUND WATER ELEVATION AND GRADIENT <br /> -> The depths to -ground water in wells MW-1 through MW-4 were.measured between 59.04 and <br /> 60.75 feet below the tops of well casings; ground water elevations in wells MW=1 through MW-4 <br /> were calculated to be between 33.35 feet (MW-3) and 34.10 feet (MW-4) below mean sea level <br /> ' Figure 3). Ground water elevation at the site generally increased an average 2.73 feet between the <br /> //,July 2002 and the October 2002 ground water monitoring events. Ground water flow direction for <br /> ' Advanced GeoEnvironmental,Inc. <br /> 1 <br />