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,CvvATc <br /> A S S O C I A T E S I N C <br /> During the long-term vapor extraction test on well VW3, extraction flowrates ranging from 16 1 <br /> to 49 5 cubic feet per minute (cfm) resulted in a vacuum of up to 0 39 inches of water in wellF. <br /> ' MW2 located 6 5 feet away and 0 36 in well VW 1 located 22 feet away Vapor well VW 1 is �, <br /> screened from 15 to 35 feet bgs and monitoring well MW2 is screened from approximately 45 to 'y� <br /> 65 feet bgs Vapor well VW3 is screened from 25 to 45 feet bgs The actual radius of influence for <br /> each vapor extraction well will vary depending on subsurface geologic conditions, the extent and <br /> distribution of hydrocarbon-impacted soil, and site-specific operating conditions of the vapor extraction <br /> ' system The effective radius of influence should be evaluated following the installation and long-term <br /> operation of a vapor extraction system <br /> During the short term pilot test, influent volatile organic compound (VOC) vapor concentrations <br /> monitored with a photo-ionization detector were measured at concentrations greater than 1% <br /> resulting in a flame out in the PID meter Lack of oxygen in the airstream prevented accurate <br /> ' measurements During the long-term pilot test VOC vapor concentrations were measured at <br /> concentrations ranging from 599 to 5380 ppm Laboratory results of the vapor samples indicated <br /> that volatile hydrocarbons were detected in the influent samples Approximately 2 79 pounds of <br /> TPHg and BTEX were removed during the long vapor extraction pilot test as shown below <br /> Average concentration of TPHg in two influent vapor samples collected from well VW3 yields <br /> 1400 ppmv + 1100 ppmv) = 1250 ppmv <br /> 1 2 <br /> 1 Assuming an average flowrate of 33 67 cfm during the 4-hour vapor extraction test and using the <br /> values supplied by Sequoia Analytical of 24 5 liters of vapor per mole of TPHg and a molecular <br /> weight of 86 27 grams per mole of TPHg yields <br /> = 1250 1 TPHn x 33 67 ft x 60 min x 28 32 1 air x 1 mole TPHg x 86 27 a x 1 Ib <br /> 1,000,000 1 air min hour 1V— 24 5 1 vapor mole TPHg 454 g <br /> 0 5547 Ib TPHg = 2 218 lbs of TPHg during the four hour test <br /> hour <br /> w 1625771repoM\nfs doc 8 <br />