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Sampling and Analysis Plan for Phase II Environmental Site Assessment South Pointe Property: 701, 705, 833, 855 West Weber Avenue Stockton, California Project and Data Quality Objectives May 17, 2021 will be compared to UESPA Regional Screening Levels (RSLs, November 2020). For compounds with no established SLs or RSLs, soil data will be compared to Environmental Screening Levels (ESLs)established by the San Francisco Bay Regional Water Quality Control Board (RWQCB, 2019). • Soil vapor data will be compared to RWQCB ESLs. Steps 6 and 7— Data Collection Plan and Data Quality Objectives Analysis Soil vapor conditions will be assessed by gridding the site into 100- by 100-foot sections and collecting passive vapor samples at each of the intersecting nodes. Based on professional experience, this sampling effort is appropriate for`reconnaissance level' assessment of soil gas conditions across the 9- acre site where there are no currently known or suspected sources of impacts to soil vapor. This 100-foot grid spacing is also consistent with specifications provided by the manufacturer of the passive soil vapor samplers (Beacon Environmental; their SOP and laboratory accreditation certificate are included in Appendix C). Samples will be analyzed by the laboratory and results used to guide the collection of active vapor samples at up to an estimated ten locations. Active soil vapor samples will be collected from multiple depths, anticipated to be approximately 5 and 12 feet below grade. Soil vapor samples will be analyzed by the analytical laboratory to quantify concentrations of VOCs in soil vapor. Soil conditions will be assessed by advancing test pits at 20 locations for collection of soil samples. Test pits will be advanced at locations where previous data indicate incomplete vertical delineation of OCPs in soil. Test pits will be extended to an anticipated target depth of 10 feet below grade to examine shallow fill materials (previously identified to between ground surface and approximately 5 feet bgs across most of the site)and underlying native materials. It is anticipated that three soil samples will be collected from each test pit, one from the mid-point of observed fill materials, and two from underlying native materials. Samples will be collected into laboratory-supplied containers and analyzed for OCPs and lead by an accredited analytical laboratory. The sampling and analysis plan has been designed using best professional judgement to be representative of the area being assessed. Analytical practices will adhere to industry technical standards. Soil samples will be analyzed for OCPs by USEPA Method 8081 B. Soil vapor samples will be collected in accordance with current guidance published by California DTSC (Advisory, Active Soil Gas Investigations, July 2015) and analyzed by USEPA Method TO-15. Passive soil vapor samples will be collected using American Society for Testing and Materials (ASTM)-compliant sample modules and analyzed using USEPA Method 8260C. Measurement error, rather than sampling error, is deemed the primary factor affecting any decision error. Validated definitive data will be required to limit measurement error. Sampling error will be limited to the extent practicable by following approved USEPA methods and applicable SOPs. In addition, the following conditions apply to the sampling plan. • It is assumed that current and future use of the site will be for mixed use residential and commercial. Exposure pathways of concern include potential direct contact with shallow soil, inhalation of dust particulates during redevelopment activities, and ingestion of soil by future `1 Project No.: 185704833.5.3&5.4 3.3