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<_15 November 2002 . <br /> AGE-NC Project No. 95=0173 <br /> Page,-6 of 8 <br /> J. <br /> Between 11 June 2002 and '26_Septernber 2002,,the SVE unit operated a total..of 2,118 hours <br /> - (Table 6). The. average analytical results (approximately 548 yg/l).of the SVE".air flow_samples <br /> (Table-5),-average flow-rates. (approximately -98 cfm; Table 6) and the operational .period <br /> __- - <br /> y 2;118.hours -were used to calculate the-,approximate massof extracted gasoline during this period. <br /> A. <br /> IL <br /> Duringthe June, July, August and September-2-002 period, the mass.of hydrocarbons extracted by <br /> _the SVE-systerri was-calculated:to be;.approximately 426 pounds, or equivalent to a volume of j <br /> x:68:2 gallons of gasoline:Added to the estimated 1,280gallons of hydrocarbons extractedfrom the, I <br /> SVE�system.since 1'1.April 2000.(start-up),-the total volume of hydrocarbons extracted to date is <br /> r <br /> .-,:estimated at 1,348 gallons (Table 7). A plot of.the.cumulativewolurrie (gallons) of.hydrocarbons <br /> L extracted to date as included with Appendix E. The'mass/volume. calculations for extracted.,f <br /> hydrocarbons:are included with:Appendix F <br /> y <br /> 5 0. CONCLUSIONS w <br /> `The.implications.from-the.September 2002-ground,water monn <br /> rtong event,are as follows: t <br /> .0 :;-Ground-.water flow direction at.the'site was genefally.toward-the northeast at agr adient of <br /> .0. 4, ft/ft'or'less:Due to''the low gradient at the site,'-slight variations in ground water � <br /> ' r. .measurerrients 'or;chan 'es of.rechar e/dischar'e of the local, ound water <br /> g g g gr could' greatly l <br /> x modrfy ground water-flow direction y <br /> :The decrease of ground water.elevation::ofapproximately 3.01 feet Between June 2002 and. <br /> =September 2002 is probably due to seasonal <br /> :fluctuation. } <br /> Ground water-at:the site was approximately.l0 feet.and.39 feet above the 4screen intervals 1 <br /> drowned of wells. AW-1B AW-2A-,and - <br /> ) .,: d AW 2B and may not yield samples fully <br /> represeritativc of shallowest ground water conditions.,The ground-water elevation appeared' <br /> to:.be::within._or�near -the .screen'Fintervats of-a11 other. well's at the site and should be, <br /> representative of shallowest ground water conditions: <br /> Ground watei elevation daiacollected on.20 September 2002 does not suggest ground water. <br /> mounding is'.occuiring due to'air sparging at the'site. - <br /> • ° The elevated concentrations ofpetroleum hydrocarbons detected in samples collected from '.-. <br /> wells MW=3,;MW-.4;'AW-1 and,AW-2 indicate.that'these wells are within the dissolved _ <br /> petroleum Yiydrocarbori "core-area".o f the plume.(Figures4). <br /> f •.' The highest dissolved petroleum hydrocarbons:weredetected mthe area ofwell AW-2;there, <br /> t does not appear to be.rnuc'h-varii ti6ri'in',the diss6ived`,vliiine"located between_AW-2A (40 <br /> 4, _ `to 45,feet bsg) and AW 2B,{60 to 70 feet bsg). { <br /> ' - Advanced GcoEnvironmental,Inc. <br /> J <br /> r <br /> ,.-. Z. ' y <br /> r <br />