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29 October 2002 <br /> • AGE-NC Project No 99-0637 <br /> Page 2 of 3 <br /> chain-of-custody to McCampbell Analytical Inc , a California Department of Health Services- <br /> certified laboratory The samples were analyzed for <br /> • Total petroleum hydrocarbons quantified as gasoline (TPH-g) and diesel (TPH-d) in <br /> accordance with EPA Method 8015 Modified, <br /> • Benzene, toluene, ethylbenzene and total xylenes (BTEX) in accordance with EPA Method <br /> I 8260B, and <br /> • Fuel additives including methyl tertiary-butyl ether(MTBE),di-isopropyl ether(RIPE),ethyl <br /> tertiary-butyl ether (ETBE), tertiary-amyl methyl ether (TAME), tertiary butanol (TBA), <br /> Iethylene dibromide (EDB) and 1,2-dichloroethane (1,2-DCA) in accordance with EPA <br /> Method 8260B <br /> 3.0. FINDINGS <br /> Ground water elevation, flow direction, and gradient were determined from field data collected on <br /> 18 July 2002, the contaminant impact to ground water was quantified by the laboratory analytical <br /> data <br /> I3 1 GROUND WATER GRADIENT AND FLOW DIRECTION <br /> At the time of the July 2002 sampling event, depths to ground water in wells MW 1 through MW7 <br /> Iranged from 18 96 feet to 19 94 feet below the well heads Ground water elevations at the site ranged <br /> from 14 15 feet above mean sea level(MSL) in well MW5 to 14 59 feet above MSL in well MW2 <br /> (Table 1) During this monitoring event,the depths to ground water in the wells were approximately <br /> I 8 96 to 9 94 feet below the tops of the well screens, indicating that the wells are screened properly <br /> to yield representative shallow ground water samples <br /> The ground water flow direction was inferred using ground water elevation data from the monitoring <br /> wells on-site The flow direction was inferred to be toward the northwest, at an average gradient of <br /> 0 004 feet/feet Figure 3 illustrates the contoured ground water elevations as measured on <br /> 18 July 2002 <br /> 3 2 ANALYTICAL RESULTS OF GROUND WATER SAMPLES <br /> MTBE was detected in the ground water samples collected from wells MW4, MW5 and MW6 at <br /> • concentrations of 3,800 gg/l, 3,600 µg11 and 14 gg/l,respectively No other analytes were detected <br /> at or above laboratory reporting limits an the ground water samples <br /> IAdvanced GeoEnvironmental,Inc <br />