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Further risk assessment was conducted via the Environmental Protection Agency—Office of Land and Emergency Management (EPA-OLEM) vapor intrusion risk assessment guidance (updated June 2017). For the highest benzene and naphthalene concentrations (29.5 µg/m3, and 13.3 µg/m3, respectively ), the cancer risk is 5.6x10- 7, and 1.1x10-6 which are both less than the 1x10-5 target risk for carcinogens for commercial site. Utilizing the highest concentrations of benzene and naphthalene as a "worst-case scenario", the calculated cumulative hazard quotient is 0.04, which is less than the target hazard quotient for non-carcinogens (less than 1.0). Therefore, no human health risk or reportable condition is present from constituents detected in soil vapor on the subject property at this time. The EPA OLEM calculation sheet is included in Appendix E. Three (3) groundwater samples were collected and analyzed for VOCs and TPH. One detection of MTBE was detected in S133. All other groundwater sample results are below their respective ESLs, where published, with the exception of TPH-DRO. TPH-DRO was detected above the ESL of 100 µg/L in groundwater samples collected from S131 and S133 at respective concentrations of 981 µg/L and 213 µg/L. Based on recent data obtained from a nearby LUST cleanup site, groundwater is expected to flow in a westerly direction. Based on the limited scope of this investigation, additional groundwater sampling is needed in order to verify if TPH-DRO concentrations detected in groundwater originate from an on-site or off-site source. 7.0 Conclusions and Recommendations FR conducted a Phase II Limited Subsurface Investigation at 2546 Turnpike Road, Stockton, California 95206 (subject property) per the request of Pride Group Enterprises. The purpose of this investigation was to assess subsurface conditions based on historic land use and site operations. All VOC and TPH results in soil were below detection limits for the samples analyzed. Low concentrations of metals were detected in one or more soil samples. All soil results are below their applicable screening levels under California DTSC guidance or within expected background concentration ranges. Elevated soil vapor results were reported for benzene and naphthalene. However, industry standard attenuation factors predict contaminant concentrations below indoor air screening levels using two of the three attenuation factors. Further risk assessment conducted using EPA-OLEM vapor intrustion risk assessment guidance indicate that no human health risk or reportable condition is present from contaminants detected in soil vapor at the subject property at this time. However, elevated concentrations of TPH-DRO were detected in two out of three groundwater samples analyzed above the TPH-DRO ESL of 100 µg/L. Therefore, further investigation is recommended to assess or delineate groundwater conditions at the subject property. Limitations This Phase II Limited Subsurface Investigation report was prepared for the site at 2546 Turnpike Road,Stockton, California 95206 (subject property) per the request of Pride Group Enterprises. Fulcrum Resources Environmental has applied appropriate scientific judgment and used suitable measures consistent with accepted industry standards of practice for site assessments. Fulcrum Resources Environmental makes no expressed or Phase II Limited Subsurface Investigation Fulcrum Resources Environmental 2546 Turnpike Road,Stockton, California 95206 202107-8656 12