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Kennedy/Jenks Consultants <br /> Section 2: Field Sampling Plan <br /> Considering existing information and the RI objectives, this section presents a soil and <br /> groundwater sampling plan for each OU that was developed for characterization of subsurface <br /> conditions. Samples to be collected from each AOI of each OU are summarized below and <br /> detailed on Tables 1 and 2, for soil and groundwater matrices, respectively. Proposed sampling <br /> locations in each OU and AOI are shown on Figure 4. <br /> 2.1.1 Operable Unit 1 <br /> Kennedy/Jenks will collect soil samples from the three AOIs to further assess the vertical and <br /> lateral extent of lead in soil, as specified below. <br /> • AOI 1 — Remediated Soils: Two soil borings will be advanced near areas formerly <br /> remediated by excavation and backfilled with clean imported fill material during prior site <br /> activities. Soil samples will be collected adjacent to former excavation limits at depths <br /> corresponding to and beneath the fill areas. Analysis of these samples will be used to <br /> characterize the potential for lead impacts to soil previously characterized as clean. Soil <br /> samples will be collected from each boring at three depth intervals (2 to 3 feet, 5 to <br /> 6 feet, and 10 to 11 feet bgs) and analyzed for total and soluble lead. <br /> • AOI 2— Stabilized Lead: Six soil borings will be advanced to facilitate lateral and <br /> vertical characterization of lead concentrations in soil containing previously stabilized <br /> lead. Soil samples will be collected at depths within and beneath the vertical limits of the <br /> former excavation area. Soil samples will be collected from each boring at three depth <br /> intervals (2 to 3 feet, 5 to 6 feet, and 10 to 11 feet bgs) and analyzed for total and <br /> soluble lead. <br /> • AOI 3 — Residual Elevated Lead: Ten soil borings will be advanced around the <br /> perimeter of the stabilized lead area to assess lead concentrations in soil previously <br /> characterized as containing elevated concentrations of lead. Analysis of these samples <br /> will be used to characterize the lateral and vertical extent of potential lead impacts to soil <br /> where soil remediation has not yet been performed. Soil samples will be collected from <br /> each boring at three depth intervals (2 to 3 feet, 5 to 6 feet, and 10 to 11 feet bgs) and <br /> analyzed for total and soluble lead. <br /> Because previous groundwater monitoring of six wells was completed for three consecutive <br /> quarters and dissolved lead was not detected in any of the samples, no further groundwater <br /> sampling is proposed for OU-1. <br /> 2.1.2 Operable Unit 2 <br /> Sample locations have been chosen within each AOI of this OU to assess potential chemical <br /> impacts associated with former site improvements and associated activities, including possible <br /> waste disposal or storage in the former ponds, oil storage and transmission, railroad-related <br /> maintenance and repair, and railroad tracks. Kennedy/Jenks will collect soil and reconnaissance <br /> Remedial Investigation Work Plan Page 8 <br /> Former Tracy Railyard, Tracy, California <br /> 9:Ys-groupWrNnWbW510565777.03_eprrl09-reportslwork planlri BnarbAdoc <br />