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i <br /> 03 January 2002 <br /> • AGE-NC Project No 96-0229 <br /> Page 2of5 <br /> 2 2 GROUND WATER SAMPLING <br /> Following well purging, ground water levels from each well achieved a minimum of 80 percent <br /> recharge prior to sample collection except for MW-1 which was purged"dry" Ground water samples <br /> were collected from the purged wells utilizing new, disposable polyethylene bailers and 40-m1 EPA- <br /> approved VOA vials containing 0 5 ml 18% hydrochloric acid as a sample preservative Care was <br /> taken to ensure that visible air bubbles were not present in the vials after filling and capping Ground <br /> water sample containers were labeled with the well designation, date, time, and sampler's Initials <br /> I2 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 <br /> for <br /> I • Total petroleum hydrocarbons quantified as gasoline TPH-g)by EPA Method 5030/8015M, <br /> I • Benzene, toluene, ethyl benzene and xylene(BTEX) and methyl-tertiary butyl ether(MTBE) <br /> by EPA Method 8020, and <br /> o Methanol, ethanol, tertiary butanol (TBA), di-Isopropyl ether(DIPE), ethyl tert butyl ether <br /> (ETRE), 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 /> 25 September 2001,the contaminant Impact to ground water was quantified from the laboratory data <br /> 3 1 RELATIVE GROUND WATER ELEVATION AND GRADIENT <br /> 1JU1111� Li1C 2J Sefltelllu 2VV1 111oilitolilig GVerlt, deptli5 to g"tOurid watCr iii wCiiS ivirvr-i ti'Lvug"a <br /> MW-10 were measured between 28 92 and 3127 feet below the tops of the well casings, ground <br /> water elevations were calculated to be between 18 35 feet and 20 75 feet below mean sea level <br /> Ground water elevation at the site decreased an average 2 17 feet between the June 2001 and the <br /> September 2001 ground water monitoring events,generally,decreasing ground water elevations were <br /> observed at the site between March and September 2001 (Table 1) The ground water elevation data <br /> for MW-1 through MW-10 during the September 2001 ground water monitoring event is depicted <br /> and contoured in Figure 3 <br /> Advanced GeoEnvironmental,Inc <br />