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Soil encountered during drilling consisted of sand, clay, and silt to a depth of 25 feet bgs (the maximum depth explored). Groundwater was encountered at the site in all borings at approximately 23 feet bgs. 5.0 Analytical Results The Department of Toxic Substances Control (DTSC) Human and Ecological Risk Office (HERO) is the primary authority in California for environmental assessment of contaminated sites in the state. In addition,San Francisco Bay Regional Water Quality Control Board (SFBRWQCB or Waterboard) has published interim guidance for soil, groundwater, air, and soil vapor intrusion screening levels (ESLs). Various DTSC and Waterboard screening levels are referenced in the tables of this report to evaluate the laboratory results as they apply to the various exposure scenarios (such as residential, industrial/commercial, and/or construction worker property use/exposure). The SFBRWQCB ESLs issued in January 2019 are the current industry standard in California for preliminary environmental groundwater and soil vapor screening.These ESLs are not cleanup action levels; do not necessarily indicate contamination; and are intended for use as guidance only. DTSC HERO issued an updated Human Health Risk Assessment (HHRA) Note No. 3 in June 2020. In this note, DTSC makes recommendations regarding the methodology and use of the U.S. EPA Regional Screening Levels(RSLs)and DTSC-modified screening levels(jointly referred to herein as "DTSC Recommended SLs") for soil vapor screening under residential and commercial/industrial land use scenarios. The DTSC-Recommended SLs for evaluating soil vapor intrusion are calculated using indoor air screening levels and recommended attenuation factors. These calculated soil vapor screening levels are typically applied to samples collected no more than five feet below ground surface and have been developed for both existing buildings and future buildings (DTSC and CaIEPA, October 2011). The values calculated using Note No. 3 recommendations are considered conservative, and concentrations in excess of the calculated DTSC- Recommended SLs are not considered conclusive evidence of adverse risks to human health. Depending on VOC concentrations, distribution, land use, and other factors, additional investigation such as soil vapor sampling, indoor air assessments, site-specific health risk assessments, etc. may be warranted to further assess site-specific health risks. Analytical results compared to the applicable screening levels are described below, and in summary Tables 1 through 7 at the end of this report. All laboratory analytical data is included in Appendix D of this report for reference. 5.1 Soil Results Selected soil samples were collected from soil borings SB1 through S133 and analyzed for one or more of the following analytical suites: VOCs via EPA Method 826013; TPH (full-range organics) via EPA Method 801513; and CAM 17 Metals via EPA Methods 6010B and 7471A. The soil sample results are summarized below. VOCs Three (3) soil samples were collected and analyzed for VOCs via EPA Method 8260B. All VOCs were below detection limits in all soil samples analyzed and are below the applicable industrial/commercial screening levels. The soil VOC results are presented in Table 1. Phase 11 Limited Subsurface Investigation Fulcrum Resources Environmental 2546 Turnpike Road,Stockton, California 95206 202107-8656 9