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Workplan for Limited Subsurface Investlgatlon <br /> Tahoe Tom's Gas Station <br /> PROPOSED INVESTIGATION <br /> Apex proposes to drill two soil borings on site (Figure 3) and complete one of the borings as a <br /> 4-inch-diameter vapor extraction well (VEW-1). The remaining boring will be completed as a 1- <br /> inch diameter air sparging point (AS-1). All fieldwork will be conducted according to the Apex <br /> SOP included in Attachment 1. <br /> The well will be constructed according to the Apex SOP included in Attachment 1 and include <br /> 0.02-inch perforated casing. The filter pack will be placed from 2 feet above the screen interval to <br /> total depth. The bentonite seal will be placed from 2 to 4 feet above the screen interval and a <br /> bentonite/cement slurry will be placed from near surface to 4 feet above the screen interval. The <br /> vapor well will be secured with a locking, water-tight cap and a 12-inch-diameter traffic-rated <br /> wellhead vault (Figure 4). The proposed well is anticipated to be drilled to a total depth of 15 <br /> feet BG and screened from 5 to 15 feet. The screened interval is based on groundwater at 10 feet <br /> BG at the site. <br /> SOIL SAMPLING <br /> Soil samples will be screened in the field for selection of one or two from each boring to be 4 <br /> submitted, under chain-of-custody, to a state-certified laboratory for analysis of total petroleum <br /> hydrocarbons (TPH), as gasoline, TPH, as diesel, and benzene, toluene, ethylbenzene, and total <br /> xylenes (BTEX)by modified EPA Method 8015 and 8020, respectively. <br /> Soil samples will be collected at five-foot intervals, obvious lithologic changes, or at noticeable <br /> hydrocarbon odors. All drill cuttings will be temporarily stockpiled on site, under and on plastic <br /> sheeting, pending receipt of the analytical results. <br /> I <br /> i <br /> • 0 <br /> I <br /> f <br /> I <br /> { <br /> j <br /> 2 <br />