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rp <br />' 16 October 2000 <br /> i AGE-NC Project No 98-0520 <br />' Page 2 of 3 <br />' 2 2 COLLECTION AND ANALYSIS OF GROUND WATER SAMPLES <br /> Water samples were collected from each well using a new disposable plastic bailer Each water <br />' sample was transferred into three 40-m1 volatile organic analysis(VOA) vials containing 0 5 ml 18% <br /> HCl as a sample preservative and into one 1-liter amber bottle without preservative After collection, <br /> the samples were labeled and placed in a chilled container for transportation under chain-of-custody <br />' to McCampbell Analytical Laboratory(MAI)of Pacheco, California Each sample was analyzed for <br /> • Total petroleum hydrocarbons quantified as gasoline and diesel (TPH-g and TPH-d) in <br />' accordance with EPA Method 8015 Modified and <br /> • Volatile aromatic compounds benzene, toluene, ethyl-benzene and total xylenes (BTEX), <br />' and oxygenates di-isopropyl ether (DIPE), ethyl tertiary-butyl ether (ETBE), ethanol, <br /> methyl-tertiary butyl ether(MTBE), tertiary-amyl methyl ether(TAME) and tertiary-butanol <br /> (TBA) in accordance with EPA Method 8260 Modified <br />' 3.0 FINDINGS <br /> Ground water elevation and flow direction were calculated from field data, the hydrocarbon impact <br /> Ito ground water was assessed by laboratory analysis <br /> 3 1 GROUND WATER ELEVATION, FLOW DIRECTION AND GRADIENT <br /> Depth to ground water at the site ranged from 9 77 to 10 45 feet below the well casing tops The <br /> I ground water elevations at the site ranged from 88 82 feet to 89 03 feet above mean sea level (msl) <br /> The ground water elevation increased approximately 0 77 feet over the quarter <br /> The ground water flow direction and gradient were calculated from the ground water elevation data <br /> Contours of the ground water elevation data indicates that the ground water flow was directed toward <br /> the northeast from the former UST area The ground water gradient on site was calculated to be <br /> 0 0026 under the former UST Figure 3 illustrates the contoured ground water elevations <br /> I3 2 HYDROCARBON-IMPACTED GROUND WATER <br /> MTBE was detected in the ground water samples collected and analyzed from well MW-4 at a <br /> concentration of 2 0 micrograms per liter (,ug/1) <br /> I • TPH-g, TPH-d, BTEX, DIPS, ETBE, TAME and TBA compounds were not detected in the ground <br /> water samples collected and analyzed from the site <br /> r <br />� r <br />