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12 June 1996 <br /> AGE-NC Protect No 95-0104 <br /> Page 3 of 5 <br />' 3 2 GROUND WATER SAMPLING <br /> Monitoring wells MW-I through MW-4 and VW-1 were allowed to recover for a minimum of one <br /> hour prior to sample collection Ground water samples were collected utilizing dedicated, disposable <br /> polyethylene bailers and new nylon rope Sufficient sample was collected from each well to fill three <br />' 40-m1 EPA vials containing hydrochloric acid as a preservative for the samples Care was taken to <br /> ensure that visible air bubbles were not present in the VOAs after filling and capping Ground-water <br /> sample containers were labeled with the well designation date, time, and sampler's initials <br /> 3 3 LABORATORY ANALYSIS OF GROUND WATER SAMPLES <br />' After collection, each sample was logged on a chain-of-custody form, placed in a chilled container <br /> and transported to a Alpha Analytical Laboratories (AAL), a California state-certified laboratory for <br /> analysis of hazardous materials Each sample was analyzed for TPH-g, volatile aromatics (benzene, <br /> toluene, ethyl benzene and xylene BTE&X), methyl-tertiary butyl ether (MTBE) and halogenated <br /> volatile organic compounds (HVOCs)in accordance with EPA methods 5030, 602, 5030/602 and <br /> 601, respectively <br />' 40 FINDINGS <br />' 41 RELATIVE GROUND WATER ELEVATION AND GRADIENT <br /> The relative surface ground water elevation on 24 April 1996 is depicted in Figure 3 The depths to <br />' ground water in wells VW-1 and MW-1 through MW-4 ranged between 63 75 and 64 96 feet below <br /> the tops of the well casings, and on the average rose approximately 5 97 feet between January 1996 <br /> and April 1996 The top of the screen intervals from wells MW-2, MW-3 and MW-4 are <br />' approximately 16 to 17 feet below the ground water table <br /> In January 1996, the ground water gradient at the site was calculated to be 0 005 ft/ft or <br /> approximately 26 feet per mile, directed N 12° W (Figure 3) In April 1996, the gradient was <br /> calculated to be 0 0025 ft/ft or approximately 13 feet per mile, directed N 62°E Between January <br /> and April 1996, ground water flow direction beneath the site rotated approximately 74' from <br />' northwest to northeast <br />' 42 ANALYTICAL RESULTS OF GROUND WATER SAMPLES <br /> During the Apnl 1996 sampling, TPH-g was detected in samples collected from MW-1 and VW-1 <br /> I <br />