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Sampling and Analysis Plan for Phase II Environmental Site Assessment <br /> 125 North Stockton Street, Lodi,CA 95240 <br /> 2.2.3 Step 3 - Required Information <br /> The following new data inputs, combined with existing information, will be used to determine <br /> whether contamination is present at the Site at levels that could pose a threat to human health, <br /> or which could complicate or add significant costs to future redevelopment efforts. <br /> • Geophysical survey. A geophysical survey, using electromagnetic detection equipment <br /> and ground penetrating radar, will be completed by a licensed contractor to evaluate <br /> the potential presence of an UST historically present at the Site. Geophysical methods will <br /> also be used to ensure that proposed borehole locations are free of detectable <br /> subsurface utilities or obstructions. <br /> • Soil sampling. Ten soil borings will be advanced to depths ranging from 5 to 15 feet below <br /> ground surface (bgs) to evaluate subsurface soil conditions beneath the Property (four <br /> borings will be advanced to 15 feet bgs purely to facilitate soil vapor probe installation, <br /> described below). Discrete soil samples will be collected from each of the ten borings at <br /> approximate depths of 0.5-1 feet, 3 feet, and 5 feet bgs, and deeper soil samples will be <br /> collected in the vicinity of the historical UST (from 10 and 15 feet bgs). Samples will be <br /> analyzed for one or more of the following: PAHs, arsenic, lead, asbestos, VOCs, and total <br /> petroleum hydrocarbons speciated as gasoline, diesel, and oil range organics. For <br /> boreholes intended to delineate shallow soil impacts, deeper samples will be held by the <br /> laboratory pending analysis of shallow samples and analyzed only if vertical delineation of <br /> COCs is warranted based on the shallow data.Table 2 summarizes the analytical program <br /> and assigns rationale for the chemical analyses selected for each sample. <br /> • Soil vapor sampling. Temporary soil vapor probes will be installed at 5 and 15 feet bgs at <br /> four locations on the Property to evaluate potential soil vapor impacts from onsite sources <br /> (such as the former UST, the former MGP, and historical spills within the equipment repair <br /> building) and from the documented regional solvent plume in groundwater. Soil vapor <br /> samples will be collected and analyzed for VOCs including gasoline range hydrocarbons. <br /> Helium will be used as a tracer gas during sampling, and samples will be analyzed for <br /> helium to assess potential breakthrough of ambient air during sampling. <br /> 2.2.4 Step 4 - �Tuay tsoundaries <br /> The following spatial boundaries will be established based on environmental media to meet data <br /> quality objectives: <br /> o Soil sampling: At strategic locations spatially distributed on the Property to target <br /> current or historical potential chemical source areas identified by the Phase I ESA. <br /> Locations will be adjusted as necessary to avoid underground utilities or obstructions. <br /> o Soil vapor sampling: At strategic locations spatially distributed on the Property to <br /> target current or historical potential chemical source areas, and to assess ambient <br /> soil vapor conditions. Locations will be adjusted as necessary to avoid underground <br /> utilities or obstructions. <br /> Stantec <br />