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c dioxide, see Table 4 . <br /> The above results show that the weekly two hour venting of MW8, <br /> is removing excess carbon dioxide and allowing oxygen transfer to <br /> occur A calculated 0 89 pounds of gasoline range hydrocarbons <br /> has been removed from MW8 as of April 26 , 1995, see Table 4 and <br /> Appendix A. - Field Notes <br /> MW8 VENTING PROCEDURES <br /> We are using LTT vacuum trucks to pull an estimated 11 feet of <br /> water vacuum on MW8, for 2 hours weekly and exhaust directly to <br /> atmosphere This vacuum generates a flow rate of approximately <br /> 59 cfm <br /> COLLECTING SAMPLES <br /> The sample is obtained from a sample port located, prior to the <br /> vacuum pump from a sample port on the flow meter orifice Sterile <br /> poly tubing was used to attach a one liter tedlar bag, fitted <br /> with a special septum "valve" and tubing bib, to the sample port <br /> The sample port is on the vaccum side of the pump and therefore a <br /> vacuum greater than the well vacuum must be exerted on the <br /> outside of the tedlar bag to "fill" the bag with the vapor <br /> sample A special vacuum box, in which the tedlar bag is sealed <br /> inside, is used to exert a high vacuum to the exterior of the <br /> bag, thereby pulling a sample into the bag once the tedlar bag <br /> is filled, its valve is closed and locked and the appropriate <br /> label is placed on the bag <br /> The label shows the date, time, sample ID## and analyses to be run <br /> and the sampler' s initials The tedlar bag samples are then <br /> placed within a cooler, and are hand delivered to WEGE' s <br /> laboratory that same day <br /> The vapor sample is then infected into an FID (Flame Ionizing <br /> Detector) chromatograph and the resulting chromatogram compared <br /> to standard chromatograms of known TFH (Total Fuel Hydrocarbons, <br /> gasoline) and BTEX (benzene, toluene, ethylbenzene, and xylenes) <br /> concentrations . Selected samples are also analyzed by dual <br /> chromatograph comparison A Photovac 10550 photo-ionizing gas <br /> chromatograph is used to evaluate BTEX, TCE, PCE, and DCE <br /> Carbon dioxide (CO2) concentration is measured from the tedlar <br /> bag samples by connecting a Drager tube and pump to the <br /> inlet/outlet of the tedlar bag. CO2 reading in percent is then <br /> obtained and recorded on the chrmoatogram produced from the GC- <br /> FID analysis <br /> PAGE 3 R603 UPDATE-38 5/04/95 <br />