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� v <br /> TC <br /> A S S o C I A T E S I N C <br /> During the short-term vapor extraction test on well VE2, extraction flowrates ranging from 2 2 to <br /> 5 5 cubic feet per minute (cfm) resulted in a vacuum of up to 0 30 inches of water in well VE3 <br /> located 46 feet away Vapor well VE3 is screened from 30 to 50 feet bgs During the long-term <br /> vapor extraction test on well VE3, extraction flowrates ranging from 53 5 to 78 9 cfm resulted in <br /> a vacuum of up to 2 7 inches of water in well VEl located 16 feet away and 0 44 inches of water <br /> in well MW4 located 55 5 feet away Vapor well VE2 is screened from 50 to 70 feet bgs Vapor <br /> well VEl is screened from 30 to 40 feet bgs Monitoring well MW4 is screened from 70 to 90 <br /> feet bgs <br /> The actual radius of influence for each vapor extraction well will vary depending on subsurface <br /> geologic conditions, the extent and distribution of hydrocarbon-impacted soil, and site-specific <br /> operating conditions of the vapor extraction system The effective radius of influence should be <br /> evaluated following the installation and long-term operation of a vapor extraction system <br /> During the long-term pilot test VOC vapor concentrations were measured at concentrations <br /> ranging from 180 to 2,832 parts per million by volume (ppmv) Laboratory results of the vapor <br />' samples indicated that volatile hydrocarbons were detected in the influent samples <br /> Approximately 9 2 pounds of TPHg and BTEX were removed during the long vapor extraction <br /> pilot test as shown below <br /> Average concentration of TPHg in two influent vapor samples collected from well VE3Y ields <br />' = 6 2 Ppmv+ 3200 my = 1,603 ppmv <br /> 2 <br /> Assuming an average flowrate of 67 4 cfm during the 5-hour vapor extraction test and using the <br /> values supplied by SunStar Laboratories of 24 5 liters of vapor per mole of TPHg and a <br /> molecular weight of 86 27 grams per mole of TPHg yields <br /> = 1-603 1 TPHg x 67 4 W x 60 min x 28 6 <br /> x 1 mole TPHg x 8_ 27 g x 1 Ib <br /> 1,000,000 1 air min hour 1 ft 24 5 1 vapor mole TPHg 454 g <br /> 1 4 Ib TPHg = 7 0 lbs of TPHg during the five hour test <br /> hour <br />' The same calculation for benzene with 24 5 liters of vapor per mole of benzene and a molecular <br /> weight of 78 grams per mole of benzene is shown below <br /> = 0 PPmv +44 my - 22 ppmv <br /> 2 <br /> = 22 1 benzene x 67 4 fta x 60 min x 28 32 1 air x 1 mole benzene x 78q x 1 Ib <br /> 1,000,000 1 air min hour 1 W 24 5 1 vapor mole benzene 454 g <br /> = 0 0176 Ib benzene - 0 09 lbs of benzene during the five hour test <br /> hour <br /> S lEnviromentaIU529IVeportslrifs doc 4 <br />