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2.0 Scope of Work <br /> The following procedures will be used for sampling and removal of TPH-contaminated soils. <br /> This work will be conducted in accordance with the Tri-Regional Board Staff Recommendations <br /> for Preliminary Investigation and Evaluation of Underground Tank Sites (Regional Water <br /> Quality Control Board, Central Valley Region,August 10, 1990). A Site Health and Safety Plan <br /> is provided as Appendix A. <br /> 2.1 Additional Excavation and Soil Sampling <br /> IT Corporation will observe additional excavation in the vicinity of the two dispenser locations at <br /> which contamination was encountered(Figure 1). PG&E will direct the contractor to excavate <br /> until screening of soil samples collected from the base and sidewalls of the excavated area <br /> indicate soil containing relatively high concentrations of hydrocarbons have been removed. The <br /> +� screening will be conducted using a Hamby Kit. The Hamby Kit uses the Friedel-Crafts reaction <br /> with hydrocarbons to produce a colorimetric response, from which TPH concentrations can be <br /> estimated by comparison to a set of photographs. The estimated limits of the excavations are an <br /> additional ten feet maximum laterally on all sides and ten feet maximum below ground surface <br /> vertically. The anticipated volume of material to be removed from beneath the two dispensers is <br /> approximately 20 cubic yards. <br /> 2.2 Verification Soil Sampling <br /> After excavating the contaminated soils, soil samples will be collected under the direction of the <br /> San Joaquin County Public Health Services, Environmental Health Division representative. One <br /> sample will be collected from the floor and each side wall of the excavations beneath the two <br /> dispensers. Soil samples will be collected using a 2-inch-diameter hand auger and hand-operated <br /> W <br /> percussion sampling equipment. The percussion sampler will be equipped with stainless steel <br /> sample tubes. The sample tube will be sealed with Teflon®tape and plastic end caps and labeled <br /> with project number, sample designation, and sampling date. The sample will be placed in a <br /> cooled ice chest and logged on chain-of-custody documentation. Sampling equipment will be <br /> decontaminated between sample locations to prevent cross contamination of samples. <br /> The soil samples will be submitted to a state-certified analytical laboratory (Chromalab, Inc., <br /> Pleasanton, California) for analyses of TPHG and TPHD using USEPA Modified Methods 8015; <br /> BTEX using USEPA Method 8020; MTBE using USEPA Method 8260; PCBs by USEPA <br /> Method 8082; Oil and Grease; and total lead using USEPA Method 7420. <br /> V <br /> SacDP-ILVCRFPI ICOMA101OConniNingUataLSlwe"rojecuW.7l778407,d5.dac 2- <br /> /7111100 <br /> 4 <br />