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Lr <br />%%.-I N%W� <br />V <br />this investigation will be evaluated and used to develop a subsequent work plan for removal of <br />the oil/water separators and excavation of impacted shallow soil, if present. Results of the <br />y investigation will also be used to design a 1i1ot testing work plan for remediation. ? <br />,r This work plan includes drilling, soil and groundwater sampling, laboratory analysis of the <br />samples, data evaluation, disposal of investigation -derived waste, and preparation of a written <br />report. Specific tasks for this scope of services are described in the following sections. <br />V <br />3.1 DRILLING, SOIL SAMPLING, AND LABORATORY ANALYSIS <br />ETIC proposes to drill 15 soil borings in the vicinity of the two former 6,000 -gallon gasoline <br />USTs, 10,000 -gallon diesel UST, fuel pump island, two oil/water separator systems, and a <br />storm water pipeline. The proposed drilling locations (H1 through H15) are shown on Figure 7. <br />Table 3 lists the proposed sampling and analysis plan for soil. Table 4 presents the proposed <br />sampling and analysis plan for groundwater. / <br />V <br />To evaluate soil quality in the vicinity of the Oil/water separators, borings H1 through H4 will <br />be drilled to approximately 25 feet bgs, and soil samples will be collected. Soil samples will be <br />collected from boring H5 which will be drilled within the former 10,000 -gallon diesel UST <br />excavation area, adjacent to former CPT boring C, to 20 feet bgs. Boring H6 will be drilled <br />adjacent to the storm water pipeline and catch basin to approximately 25 feet bgs, and soil <br />V <br />samples will be collected. Boring H7 will be drilled adjacent to former CPT boring B in the <br />former fuel pump island to approximately 55 feet bgs, and soil and ground water samples will <br />,r be collected. Borings H8 through H12 will be drilled around the perimeter and in the center of <br />the excavation for the two former 6,000 -gallon gasoline USTs. The borings will be drilled to <br />55 feet bgs and soil and groundwater samples will be collected from each boring. To evaluate <br />'-' subsurface conditions cross -gradient of the former gasoline USTs, boring H13 will be drilled to <br />approximately 55 feet bgs, and soil and groundwater samples will be collected. Borings H14 <br />and H15 will be drilled to 55 feet bgs for soil and groundwater sample collection, to investigate <br />V <br />subsurface conditions downgradient of the source area. <br />The proposed boring locations will be marked and Underground Service Alert will be notified <br />at least 48 hours prior to the initiation of field work. A private utility -locating contractor will <br />also be hired to check for the presence of underground utilities. A drilling permit will be <br />obtained from San Joaquin County Environmental Health Department. A health and safety plan <br />will be prepared and implemented during drilling and sampling activities. Each soil boring will <br />be hand augured or vacuum -cleared to a depth of 3 feet to check for utilities prior to drilling. <br />V <br />Drilling will be performed by a C57 -licensed contractor using a direct -push drilling _rig <br />,r equipped with a 2 -inch diameter sampler and drive rods. All drilling equipment and sampling <br />tools will be decontaminated prior to the start of drilling. Reusable sampling equipment will be <br />00 <br />