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¢\Protect$\5Al92�+�nvr+ep <br /> inch by 2-inch brass rings lining a split-spoon sampler. The sampler was driven 18 inches <br /> into undisturbed soil before being retrieved and split open to remove the rings. The ends <br /> of the lowermost ring were covered with teflon sheets before being capped, sealed with duct <br /> tape, labeled, and stored in an ice chest for possible laboratory analysis. Soil from the <br /> other rings was screened by sight, odor, and with a photoionization detector Organic Vapor <br /> Analyzer for hydrocarbons. Soil samples and cuttings from the boring were logged and <br /> geologically described by a geologist on site. Samples from the boring show that the soil <br /> beneath the site consists primarily of brown clayey to sandy silt, with some sand intervals <br /> encountered (Appendix A - Boring Log). <br /> 2.2 Monitoring Wella Comsttraacdom <br /> Ground-water was noted during drilling at approximately 92 feet. The well was drilled to <br /> 103 feet, screened with 0.02-inch slotted ]PNC casing from 103 to 83 feet and sand-packed <br /> s <br /> with #2/12 Monterey sand from 103 feet to 73 feet. A 2-foot layer of bentonite pellets was <br /> + added from 73 to 71 feet, and neat cement grout was tremied around the blank PLIC casing <br /> as a seal from 71 feet to the surface. A locking well cap and traffic-proof well box were <br /> installed at the surface. <br /> 2.3 Gmu nd-Wattear Gradient <br /> The ground-water gradient was determined using UST-1 and three other momtoring wells <br /> (SI-1, SI-2, and SI-3) on site installed as part of another investigation approximately 500 feet <br /> from the fueling area (Figure 1). The four wells encountered ground water at <br /> approximately 83 to 92 feet during drilling. Static ground-water levels in the wells were <br /> measured at 84 to 85 feet on September 25, 1990, except in Well SI-3, where a ground- <br /> water level was not obtained because of excessive silt in the well casing. Figure 1 shows <br /> the ground-water gradient is approximately .00063 ft/ft or 3.3 ft/mile, to the west. <br /> 2.4 Soil and Giround-Water Analytical Results <br /> Soil containing hydrocarbons was encountered during drilling from 10 to 80 feet based upon <br /> field observation and on-site organic vapor analysis. Soil samples from 50, 70, and 85 feet <br /> 2 <br />