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Drilling Permit Application — Scope of Work 1021 Industrial Dr, 944 Zephyr St, and 1010 Zephyr St Stockton, California APN: 17728014, 17728013 and 17728012 BACKGROUND Ramboll US Consulting, Inc. (Ramboll) has been retained to perform a subsurface investigation to evaluate soil and groundwater conditions in at three adjacent properties in Stockton, California; 1021 Industrial Drive, 944 Zephyr Street, and 1010 Zephyr Street. This work is being performed is support of a real estate transaction and potential redevelopment of the site. The site was historically used for agricultural purposes between the 1930s and the 1970s. The site is developed with several buildings and structures primarily located in the central and eastern portions of the site, including offices, the former mill house and refinery building, a former rail washing and loading building, a guard house, and several warehouses. Ramboll understands the facility on the site is no longer in operation. SCOPE OF WORK Pre-Field Activities Prior to mobilizing for the sampling activities, Ramboll will prepare a health and safety plan, and retain subcontractors for the completion of the work, including a utility clearance subcontractor, a drilling subcontractor, and analytical laboratory subcontractors. Ramboll will mark the site for One-Call utility notification and will contact Underground Services Alert (USA) at least two working days prior to sampling, as required by law. Drilling and Sampling All soil and groundwater borings will be advanced using direct-push technology (DPT) drilling equipment operated by a C-57 licensed drilling contractor, as required by SJCEH. Soil cores withdrawn from the subsurface will be screened for VOCs using a photoionization detector (PID), and soil sampling depths may be adjusted based on field observations and/or VOC screening. Groundwater samples will be collected through temporary polyvinyl chloride (PVC) casing installed for that purpose. Ten (10) boreholes will be advanced in parking lot areas or former exterior chemical storage areas to investigate potential impacts from historical activities at the site. The attached figure shows the tentative proposed boring locations, subject to revision pending underground utility clearance and access considerations. The borings will be advanced to a depth of approximately 40 feet below ground surface (bgs) to allow for collection of shallow groundwater, which is reportedly present at approximately 32 feet bgs. Soil samples will be collected at depths of approximately 1 foot, 5 feet, 10 feet, and 20 feet bgs at all boring locations. The two shallowest samples will be submitted for analysis (see analytical program below), and the deeper two samples will be submitted on hold, and will not be analyzed unless review of the shallow sample results suggest a need for additional vertical delineation. Sampling depths may be adjusted based on field observations and/or VOC screening. Following soil sampling in each borehole, a grab groundwater sample will be collected with a bailer or pump through a screened, temporary PVC casing that will be dedicated for each sample.