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Objectives The objectives of the project will be to identify the location and bounds of the on-site septic systems and/or other associated features and to evaluate the potential impact of petroleum hydrocarbons and volatile organic compounds (VOCs) to soil gas and/or soil as a consequence of a release or releases from former on-site operations. To investigate the identified REC, Partner will conduct a Phase II Subsurface Investigation.The investigation scope will include a geophysical survey and the advancement of four borings to facilitate the collection and analysis of soil gas and/or soil samples. The proposed investigation scope is designed to evaluate the objective. Based on the investigation results, regulatory conditions, and/or client requirements, subsequent investigation and consulting may be necessary. Scope Sampling procedures will generally conform to the requirements of the San Joaquin County Environmental Health Department (SJCEHD), the SWRCB, the Department of Toxic Substances Control (DTSC), and the United States Environmental Protection Agency (EPA). A state-certified laboratory will analyze the samples and the project will be performed under the responsible charge of a qualified Partner representative. Laboratory results will be compared to San Francisco Bay Regional Water Quality Control Board (RWQCB) Environmental Screening Levels (ESLs). Partner will perform the following tasks for the Phase II Subsurface Investigation: • Prepare a site-specific health and safety plan; • Notify Underground Service Alert North a minimum of two business days prior to drilling activities to clear public utilities; • Secure the necessary Boring Permit from the SJCEHD. Permit acquisition will involve submitting a completed application and site plan to the SJCEHD for review and approval and remitting the necessary fees.The turnaround time of the SJCEHD to issue the permit is expected to be no more than two weeks; • Notify the applicable regulatory agencies a minimum of 48 hours prior to drilling/backfilling activities; • Perform a geophysical survey in the vicinity of the septic systems to identify the system's bounds,piping, and/or associated features and to additionally clear boring locations of utilities. Boring placement will be modified as necessary based on the geophysical survey results to avoid damaging underground features.Additionally,to the extent practical based on subsurface lithology, clear boring locations using hand tools; • Advance two borings in the vicinity of each septic system (based on data from the geophysical survey and/or historical records) to a terminal depth of 20 feet bgs, collecting soil samples in 5-foot intervals from 5 feet bgs to the terminal depth; • Field-screen each soil sample using a photoionization detector (PID); • Prepare up to 16 soil samples for laboratory analysis; • Install a temporary soil gas probe in each boring at 5 feet bgs. The final screening depth at each borehole will be adjusted based on the encountered lithology. In general, probes will be screened within coarser-grained materials and clayey/saturated intervals will be avoided, if possible; • Purge each probe, then collect and prepare up to four soil gas samples for laboratory analysis using laboratory-provided, batch-certified SUMMA canisters and flow controllers with a 5- to 10-minute sample period; • Analyze each soil gas sample(up to four soil gas samples total) for VOCs via EPA Method TO-15/8260;