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i <br /> I,I <br /> Stantec <br /> February 9,2010 <br /> Kristi Shelton <br /> Page 3 of 6 <br /> Reference: Work Plan for Additional Site Characterization <br /> i <br /> Underground Utility Location and Clearance <br /> Stantec will mark the locations of the proposed-soil 'borings in accordance with Underground <br /> Service Alert (USA) guidelines, and notify USA of upcoming subsurface activities so that existing <br /> underground utilities in the area of proposed work can be located and marked. Stantec will contract <br /> with a private utility locator to confirm that each of the proposed locations are free of detectable <br /> subsurface utilities or obstructions. <br /> i <br /> Advancement of Soil Borings <br /> i <br /> Soil borings SB-56, SB-713, and SB-813 will be advanced to first-encountered groundwater, <br /> anticipated at approximately 28 feet below ground surface (bgs). Soil borings will be located <br /> immediately adjacent to their corresponding previous locations as illustrated on Figure 2. The <br /> upper five feet of each borehole will be advanced using hand tools to confirm the absence of <br /> subsurface utilities or obstructions, and then advanced to total depth using direct-push equipment. <br /> Soil borings will be logged continuously for lithology and for field evidence of chemical impact. Soils <br /> from representative intervals will be segregated and screened for the presence of volatile organic <br /> vapors using a photoionization detector(PID). Field observations, lithologic classifications, and PID <br /> readings will be recorded on soil boring logs. <br /> Soil Samplinq and Analysis <br /> I <br /> Soil samples will be collected from the interval between 10 feet bgs (the proposed depth of <br /> remedial excavation) and first-encountered groundwater. Soils exhibiting field evidence of chemical i <br /> impact will be retained for chemical analysis, and effort will be made to collect at least one <br /> apparently ',clean' sample from below the deepest impacted sample to provide vertical delineation <br /> of the extent of impact. Stantec estimates 'up to five soil samples from each soil boring will be <br /> retained for chemical analysis. <br /> Soil samples will be collected by cutting the soil core liner and capping each end with Teflon tape <br /> and plastic caps. Samples will be labeled and stored on ice during transport to Calscience <br /> Laboratories in Garden Grove, California. Samples will be analyzed for total petroleum <br /> hydrocarbons as gasoline (TPHg) by U.S. Environmental Protection Agency (USEPA) Method <br /> 826013, and for TPH as diesel and motor oil by USEPA Method 8015B (M). In addition, three soil <br /> samples from representative soil types will be analyzed for dry bulk density, volumetric water <br /> content, and organic carbon content in support of modeling. <br /> I <br /> I:\PG&E\French Camp\2010 Remediation\Work Plans\PGE French Camp_2010 WP_fnl.doc <br />