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• <br /> SOIL VENTING FIELD TEST <br /> Purpose <br /> Soil venting removes oil contamination from soils by inducing <br /> natural biodegradation of oil to carbon dioxide and water. A <br /> vacuum pump pulls air from above ground through the soil and into a <br /> series of underground recovery wells. As the air moves through the <br /> soil it provides the oxygen necessary for biodegradation. <br /> The purpose of the single well soil venting field test is to <br /> confirm soil venting' s feasability at Tracy and to gather data <br /> needed to design a full scale system. Specifically, we will be <br /> gathering data on the following: <br /> o Radius of influence of a single vacuum well at various <br /> flowrates. <br /> The radius of influence measures how much soil is being <br /> treated by one vacuum well. It is the horizontal distance <br /> from the well in which air is being drawn into the soil . It <br /> will be estimated by measuring the subsurface vacuums at <br /> various distances from the test well. <br /> o Removal rate of hydrocarbon due to biodegradation. <br /> The removal rate is estimated by measuring carbon dioxide <br /> concentration in vent gas (gas leaving the well) and the vent <br /> gas flowrate. This data is converted to an equivalent volume <br /> of oil to estimate the removal rate. <br /> o Concentration of hydrocarbon in vent gas. <br /> This data is needed to design a vent gas treatment system <br /> to prevent odors and comply with air emission regulatory <br /> requirements. <br /> Location <br /> The vacuum well and field test equipment will be located in the <br /> south end of the green belt north of Alden Park. This site is <br /> outside of the underground concrete slab but within the area that <br /> contains liquid oil at 8 foot depths. Plates 2 and 3 show the <br /> location and test layout. No private property will be disturbed <br /> for the test. <br /> Vacuum well <br /> A 2-inch diameter well will be installed to a depth of 16 ft. It <br /> will be screened from 6 feet below grade to the bottom of the well <br /> (See Plate 4) . A gravel pack of the appropriate sand or gravel <br /> will be placed around the screen and a bentonite/cement seal will <br /> be placed above the gravel pack. <br /> 3 <br />