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Stantec PEA WORKPLAN Proposed Lodi Energy Center Site Lodi, California 5.1.4 Boring Location and Clearance Stantec will mark the proposed boring locations with white paint, as required by law, and contact Underground Service Alert (USA) at least 48-hours prior to drilling to notify all utility operators in the area to clear the marked locations. Additionally, Stantec will hire a private utility locating service to conduct a utility clearance of the drilling area prior to conducting fieldwork to ensure that underground utilities other subsurface structures are not encountered during drilling activities. After clearance is verified by USA and the utility locator, the borings will be hand augered to a depth of approximately five feet bgs to further minimize the risk of encountering subsurface obstructions. 5.2 SAMPLING LOCATIONS A total of 20 soil borings are proposed at the Site in the locations depicted on Figure 2. The 20 locations have been selected to provide adequate coverage of the Site for site assessment purposes. An approximate 100-foot grid spacing was used. With DTSC concurrence, the prior soil analytical data will be included in the overall assessment of the Site to the extent possible, the proposed sampling locations have been spaced in order to characterize both the lateral and vertical characteristics of the vadose zone across the 4.4-acre site. Four off-site borings for background samples also are proposed for collection at a location east of the Site where the previous background samples were collected. 5.3 FIELD INVESTIGATION Following receipt of boring permits and notification of DTSC, Stantec will mobilize a C-57 licensed drilling contractor to advance the soil borings to a maximum depth of approximately 6.5 feet below ground surface (bgs). Based on available information groundwater is anticipated to occur at approximately 10 to 12 feet bgs and will not be encountered. Borings will be advanced with a combination of direct-push drilling and sampling methods following hand clearing of the first five feet of borings to avoid subsurface utilities. Soils will be field-screened using a photoionization detector (PID) and described in general accordance with ASTM D-2488 under the direct supervision of a California Professional Geologist. Additional information for the field program is described in the SAP (Appendix D). 5.4 SAMPLE COLLECTION One round of sample collection is proposed. Soil sampling will be conducted at 20 sampling locations (designated as locations 8 through 27). The sample location numbering scheme begins at 8 to avoid confusion with the previously completed sampling locations designated as number 1 through 7. The following subsections describe the process for sample collection by matrix. Step- by-step sample collection procedures and methods are described in the attached SAP (Appendix D). Field conditions that impede or prohibit sample collection will be documented, and DTSC will be notified as soon as reasonably possible. PEA WP-Lodi 10 August 13,2009