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' f <br /> I21 June 2002 <br /> AGE-NC Project No 95-0135 <br /> IPage 2 of 4 <br /> 2 2 COLLECTION AND ANALYSIS OF GROUND WATER SAMPLES <br /> I ' Prior to the collection ofound water les the depth to ground water was re-measured in each <br /> �' samples, P <br /> I well to ensure that a minimum of 80% of the Initial water volume had recharged Water samples <br /> were then collected from each well using the pre-dedicated disposable bailer The samples were <br /> transferred Into 40-m1 EPA-approved volatile organic analysis (VOA) vials containing 0 5 ml <br /> I hydrochloric acid (18%) as a sample preservative The samples were transported in a chilled <br /> container under chain-of-custody procedures to CalTech Environmental Laboratories (CTEL), a <br /> California Department of Health Services-certified laboratory, for analytical analysis The samples <br /> Iwere analyzed for <br /> Total petroleum hydrocarbons quantified as gasoline (TPH-g) in accordance with EPA <br /> IMethod 8015 Modified, <br /> • Benzene, toluene, ethyl benzene and total xylenes (BTEX) and methyl tertiary-butyl ether <br /> (MTBE) in accordance with EPA Method 8021, and <br /> • Oxygenating compounds Including MTBE,tertiary-butyl alcohol (TBA),'di-isopropyl ether <br /> (RIPE),ethyl tertiary-butyl ether(ETBE)and tertiary-amyl methyl ether(TAME),methanol, <br /> I ethanol, ethylene dibromide (EDB) and 1,2-dichloroethane (1,2-DCA) in accordance with <br /> EPA Method 8260 Modified <br /> I <br /> 3.0. FINDINGS <br /> Ground water flow direction and gradient were inferred from field data,the petroleum hydrocarbon <br /> Impact on ground water was quantified by the results of laboratory analysis <br /> I r <br /> 3 1 GROUND WATER ELEVATION AND GRADIENT <br /> During the February 2002 monitoring event, depths to ground water in wells MW-1 through MW-3 <br /> were measured between 24 68 to 26 03 feet below the tops of the well casings, the water level had <br /> Increased approximately 1 foot between October 2001 and February 2002 (Table 1) Ground water <br /> elevations were calculated to be between 12 76 feet(MW-IB)and 12 85 feet(MW-3B)below mean <br /> I sea level The ground water flow direction was Inferred to be north-northeast under a gradient of <br /> 0 008 ft/ft % <br /> IGround water elevation data for wells MW-1B through MW-3B (water table wells) during the <br /> • February 2002 ground water monitoring event is depleted on Figure 3 <br /> IAdvanced GeoEnvironmental,Inc <br />