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F <br /> Soil Sampling <br /> Soil samples for IitholoQic classification and possible laboratory analysis will be collected <br /> approximately every 5 feet from the boreholes. Samples will be obtained using a 2-inch-diameter <br /> by 18-inch-lonZn <br /> a modified split-spoon drive sampler. Soil samples for laboratory analysis will <br /> not be collected in the remaining soil boreholes due to characterization of the soil from previous <br /> investigations in these areas. Field readings of soil vapors will be monitored and noted from the <br /> sections that are sampled. A lithologic log of each borehole will be completed using the Unified <br /> Soil Classification System. The boreholes will be logged by a professional geologist working <br /> under the direct supervision of a registered geologist. Standard soil sampling procedures are <br /> described in Appendix A. <br /> Borehole soil samples will be analyzed for benzene, toluene, ethylbenzene, total xylenes <br /> (BTEX), and total petroleum hydrocarbons as gasoline (TPH-G) by U.S. Environmental <br /> Protection Agency (EPA) Methods 503018020, and 8015 Modified. One composite soil sample <br /> of the stockpiled soil will be sampled and analyzed for disposal purposes. In addition to TPH-G <br /> and BETX, the stockpile soil sample will be analyzed for STLC-lead, reactivity, corrosivity, and <br /> ignitability. <br /> Air Sparging Well Installation ; <br /> The three sparge wells will be completed with 2.5 feet of 1-inch-diameter polyvinyl <br /> chloride (PVC) 0.020-inch slotted flush-threaded casing. Blank casing will extend from the top <br /> of the perforated section to the ground surface. These wells will be installed to a total depth of <br /> approximately 30 feet. Actual depths of the boreholes and screened intervals will depend on the <br /> conditions encountered during drilling. The sparge wells will be packed with #3 sand adjacent <br /> to the screen to 2 feet above the top of the screen. A minimum 3-foot-thick layer of bentonite <br /> pellets will be placed on top of the sand pack. The remaining annular space will be grouted <br /> with bentonite-cement slurry. Wells S-1 and S-2 will be completed within existing traffic rated <br /> vaults. Well S-3 will be completed at grade using a water-tight locking cover. Typical air <br /> sparging well construction is illustrated on Figure 2. <br /> Dual Completion VES Well Installation ' <br /> i <br /> Seven dual completion wells will be installed at the site. The boreholes for the wells will <br /> be drilled to a depth of approximately 20 feet below the static groundwater level. The wells will <br /> be constructed as shown on Figure 3. Based on data from existing groundwater monitoring wells <br /> at the site, Groundwater will be encountered at approximately 1I to 12 feet bas. The 1-inch- <br /> diameter PVC sparge well casing will extend from the ground surface to the total depth of the <br /> borehole. The sparge wells will be screened in the bottom 2.5 feet of the well (27.5 to 30 feet). <br /> Number 3 Lone Star sand will be installed adjacent to the sparge well screen and will extend to <br /> 2 feet above the top of the screen. A minimum 5-foot-thick layer of bentonite pellets will be , <br /> Use or disclosure of data contained on this sheet is subject to the restriction specified at the beginning of this document. <br /> 7524UMPORTSIWORIC" <br /> t � <br />