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29 June 2002 <br /> AGE-NC Project No 97-0326 <br />' Page 2 of 4 <br />' 22 COLLECTION OF GROUND WATER SAMPLES <br /> The depth to ground water was measured in each well following evacuation to assure a minimum <br />' of 80%recharge prior to sampling Water samples were then collected using new disposable plastic <br /> bailers Each water sample was transferred into 40-m1 VOA vials containing 0 5 ml 18% <br /> hydrochloric acid as a sample preservative The sample vials were then labeled with the monitoring <br />' well designation,date,time of sampling and the sampler's Initials The samples were transported in <br /> a chilled container under chain of custody to Cal Tech Environmental Laboratories (CTEL), a <br /> California Department of Health Services-certified analytical laboratory for analysis The samples <br />' were analyzed for <br /> • Total petroleum hydrocarbons quantified as gasoline (TPH-g) in accordance with EPA <br />' Method 8015 Modified <br /> • Benzene, toluene, ethylbenzene and total xylenes (BTEX) and methyl tertiary-butyl ether <br />' (MTBE) in accordance with EPA Method 8021 <br /> • The oxygenated compounds di-isopropyl ether (DIPE), ethyl tertiary-butyl ether (ETBE), <br /> + MTBE, tertiary-amyl methyl ether(TAME), tertiary butanol (TBA), methanol and ethanol <br />,! in accordance with EPA Method 8260 Modified <br /> • The fuel scavengers ethylene dibromide (EDB) and 1,2 dichloroethane (1,2 DCA) in <br />' accordance with EPA Method 8260 <br />' 3.0. FINDINGS <br />' Ground water elevation, and flow direction were determined from field data, hydrocarbon-impact <br /> to ground water was assessed by laboratory analysis of ground water samples <br /> 3 1 GROUND WATER GRADIENT AND FLOW DIRECTION <br />' Ground water was measured at a depth of approximately 33 feet below the top of the well casings <br /> dunng the January 2002 monitoring event, which was within the screened intervals of MW2 and <br /> MW3,but approximately 2 feet above the screened interval in MW 1 The elevation of groundwater <br /> in each well was calculated by subtracting the depth to ground water from the well head elevations <br /> Ground water elevations ranged from 18 54 feet(MW 1)to 18 62 feet(MW3)below mean sea level <br /> (MSL) Ground water data is summarized on Table 1 <br /> • <br />' advanced GeoEnvironmental,Inc <br />