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f - w <br /> . r <br /> C L- EARWATER <br /> G R O U P, I N C <br /> Air samples were collected in clean tedlar bags, labeled and documented on a chain- <br /> of-custody form. All samples were analyzed by a state-certified laboratory The <br /> February 9 and March 28 samples were analyzed by Trace Analysis Laboratory, Inc in <br /> Hayward, California, and the March 6 samples were analyzed by Pace, Inc 1n <br />' Novato, California. All air samples were analyzed for TPHg by EPA 8015 (CA LUFT) <br /> and BTEX by EPA 8020 (CA LUFT). <br />' 5.3 Soil Vapor Extraction System Results <br /> Weekly FID, flow and vacuum measurements are summarized in Table 2 Influent <br /> FID readings taken at VW-1, VW-2 and VW-3 all measured 0 ppmv Influent FID <br /> measurements at VW-4 ranged from 0 to 8 ppmv, and at VW-5 from 0 to 250 ppmv <br /> The total influent air flow rate of the system with all wells connected was measured <br /> at 173 scfm on March 28, 1995 Flow rates at the individual well heads ranged from <br />' 9 3 scfm at VW-5 to 51 scfm at VW-4 Total influent vacuum was measured at 14 2 <br /> inches of water <br />' Air sample analytical results are summarized in Table 3 Influent air sample <br /> concentrations ranged from a minimum of 6 9 ppmv TPHg with all five wells <br /> running, to a maximum of 83 ppmv TPHg with only VW-5 running Effluent air <br /> sample concentrations ranged from non-detect with the carbon units on the system <br /> to 5 6 ppmv TPHg without the carbon units A copy of the laboratory results and the <br /> chain-of-custody forms are included in Appendix B <br /> Recovered hydrocarbons were calculated using the flow rates measured in the field <br />' and the laboratory analytical results Calculations are presented in Appendix C <br /> Using the results from the March 28 sampling event and- the corresponding flow <br /> rate from all five vapor wells, hydrocarbons currently being recovered by the system <br /> ' are calculated as 0 41 lb/day TPHg and 0 06 lb/day total BTEX Total hydrocarbons <br /> recovered to date (calculated by multiplying lb/day by number of days the system <br /> was operating) are estimated to be 46 5 lb TPHg, 0 16 lb benzene, 0 42 lb toluene, 0 62 <br /> ' lb ethylbenzene and 4 5 lb xylenes <br /> 1 <br /> D-102 1Q95 4 May 14, 1995 <br /> t - - <br />