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Plume and will enhance biodegradation by removing CO2 and enhancing oxygen transfer while limiting hydrocarbon removal to less than 0 1 pound per week Mr Mark Schonhoff of San Joaquin Valley Unified Air Pollution Control District, evaluating this source test as it pertains to air quality conditions in the Stockton area and has allowed Wickland to perform the weekly two hour venting of this well The weekly venting of MW8 commenced on Janaury 25, 1995 and each lasts a duration of two hours The average flow rate calculated during during these venting events is 64 cfm with an average vapor stream containing 0 111 mg/L as gasoline and 2 116 carbon dioxide, see Table 3 The above results show that the weekly two hour venting of MW8 , is removing excess carbon dioxide and allowing oxygen transfer to occur A calculated 2 39 pounds of gasoline range hydrocarbons has been removed from MW8 as of March 12 , 1996, see Table 3 and Appendix B - Field Notes . MW8 VENTING PROCEDURES WEGE is using LTT vacuum trucks to pull an estimated 7 - 10 feet of water vacuum on MW8 , for 2 hours weekly and exhaust directly to atmosphere This vacuum generates a flow rate of approximately 64 cfm COLLECTING SAMPLES The sample is obtained from a sample port located, prior to the vacuum pump from a sample port on the flow meter orifice Sterile poly tubing was used to attach a one liter tedlar bag, fitted with a special septum "valve" and tubing bib, to the sample port The sample port is on the vaccum side of the pump and therefore a vacuum greater than the well vacuum must be exerted on the outside of the tedlar bag to " fill" the bag with the vapor sample A special vacuum box, in which the tedlar bag is sealed inside, is used to exert a high vacuum to the exterior of the bag, thereby pulling a sample into the bag Once the tedlar bag is fill,, a �� ,._ , cd, iICS va-1 is c" oseu ail ' mucked and zhe appropriate label is placed on the bag The label shows the date, time, sample ID# and analyses to be run and the sampler' s initials The tedlar bag samples are then placed within a cooler, and are hand delivered to WEnF' s laboratory that same day The vapor sample is then infected into an FID (Flame Ionizing Detector) chromatograph and the resulting chromatogram compared to standard chromatograms of known TPHg (Total Petroleum Hydrocarbons, gasoline) and BTEX (benzene, toluene, ethylbenzene, and xylenes) concentrations Selected samples are also analyzed by second column chromatograph comparison A Photovac 1OS50 photo-ionizing gas chromatograph was used to evaluate BTEX, TCE, PCE, and DCE PAGE 3 RG03 UPDATE-43 3/25/96