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.- — sem"" = -°t =2?:E = <br /> I <br /> `'' �`" ' <br /> 'f.._ <br /> 71 <br /> MF �'az'.'�.... <br /> i <br />� x <br /> Coca-Cola Enterprises-West <br /> USTEC Job No. 90054.03 <br /> vapor extraction system to remediate the hydrocarbon contaminated unsaturated zone. This <br /> program estimates hydrocarbon recovery from soil vacuum extraction systems performing mass <br /> balance calculations for each chemical component present in the contaminated soil mass at <br /> discrete time steps. <br /> The following parameters were defined and input into the program: <br /> o Air Flow Rate: <br /> 20 to 40 cfm per well. However, since 99% of the petroleum hydrocarbon <br /> contamination was found in a zone 15 to 20 feet in thickness,a total air flow rate <br /> of 30 cfm was used in the VENTING program. <br /> o Spill Mass: <br /> The total mass of hydrocarbon present in the soil was estimated using the highest <br /> The concentrations in the soil at each sampling depth. A spill mass of 4,345 kg <br /> of TPH as gasoline was estimated using conservative assumptions regarding the <br /> areal extent of the contamination,the density of the soil strata and the maximum <br /> concentrations found during assessment activities. About 99% of this spill mass <br /> is located between depths of 5 to 20 feet bgs. <br /> The spill mass related to diesel range petroleum hydrocarbon contamination was <br /> estimated (using the same assumptions as above) to be about 10,405 kg. About <br /> 99% of this spill mass is located between depths of 5 to 25 feet bgs. <br /> o Spill Composition <br /> - TPH as gasoline. Since only a few compounds (BTEX) present in the soil are <br /> known, the composition of a typical weathered gasoline was modified and used <br /> in this analysis. <br /> TPH as diesel. Since only the total concentration of TPH quantified as diesel is <br /> known, its composition was obtained from a gas chromatogram aE diesel. <br /> ry low <br /> Chemical compounds that tePacomposition <br /> eve <br /> teywill not evaporate <br /> vapor pressures at normal petures, aover 0d therefore <br /> and be recovered by the vapor extraction system. <br /> The output from the VENTING program is included in Appendix J. <br /> This output shows that 99% <br /> of the TPH quantified as gasoline in the unsaturated zone will be recovered b the vapor <br /> ted <br /> v" extraction system in about two years. The output also shows that about 99%a of the estim, <br /> computer output also <br /> totalcontamintition will be remediated in about b months. The <br /> , <br /> - . <br /> 26 <br />