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1 <br />' 22 August 2002 <br /> AGE-NC Project No 99-0657 <br />' Page 2 of 4 <br />' 2 2 COLLECTION AND ANALYSIS OF GROUND WATER SAMPLES <br /> Water samples were collected from each purged well using new disposable plastic bailers after <br />' allowing the wells to achieve a minimum 80%recovery of the pre-purge water volume Each water <br /> sample was transferred into one 1-liter amber bottle without sample preservative and into three <br /> 40-m1 VOA vials containing 0 5 ml 18% hydrochloric acid as a sample preservative After <br />' collection, the samples were properly labeled, placed in a chilled container and transported under <br /> chain-of-custody to Cal Tech Environmental Laboratories (CTEL), a California Department of <br /> Health Services-certified analytical laboratory, for analysis The samples were analyzed for <br />' Total petroleum hydrocarbons quantified as gasoline (TPH-g) and diesel (TPH-d) in <br /> accordance with EPA Methods 8015-modified for fuels, <br />' - Benzene,toluene,ethylbenzene and xylenes(BTEX)and methyl ternary-butyl ether (MTBE) <br /> in accordance with EPA Method 8021, and <br />' The fuel additives MTBE, dl-isopropyl ether (RIPE), ethyl tertiary-butyl ether (ETBE), <br /> tertiary-amyl methyl ether(TAME), ternary butanol (TBA), 1,2-dichloroethane(1,2-DCA) <br />'• and ethylene dibromlde (EDB) in accordance with EPA Method 8260B <br />' 3.0. FINDINGS <br /> Ground water elevation, flow direction, and gradient were determined from field data collected on <br /> 05 July 2002, the contaminant impact to ground water was quantified by laboratory analysis of the <br /> ground water samples <br /> 3 1 GROUND WATER GRADIENT AND FLOW DIRECTION <br /> At the time of the July 2002 sampling event,depths to ground water ranged from 35 06 feet to 36 08 <br /> feet below the tops of the well casings Ground water elevations at the site ranged from 6 01 feet <br /> above mean sea level(MSL)in well MW-4 to 6 35 feet above MSL in well MW-2(Table 1) During <br /> this monitoring event, the ground water levels in the wells were approximately 5 06 to 1108 feet <br /> below the tops of the well screens, indicating that the wells are screened properly to yield <br /> representative shallow ground water samples The ground water elevation at the site decreased an <br /> average of 1 73 feet between the April 2002 and July 2002 monitoring events <br /> Ground water was inferred to be flowing toward the southwest under an average gradient of <br /> 0 005 feet/feet Figure 3 illustrates the contoured ground water elevations as measured on 05 <br /> July 2002 <br /> Advanced GeoEnvironmentai,Inc <br /> I <br />