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NO FURTHER ACTION REQUIRED REQUEST REPORT US CAN—WELTY ROAD 1. INTRODUCTION SAIC Energy,Environment&Infrastructure, LLC (SAIC)prepared this No Further Action Required(NFAR)Request Report on behalf of Chevron Environmental Management Company (CEMC) for the US Can-Welty Road site (the Site), located in Vernalis, San Joaquin County, California(Figure 1). In previous site investigations, SAIC identified the presence, and delineated the extent, of total petroleum hydrocarbons (TPH) in soil and groundwater at the Site. The Site consists of three areas of affected soil encompassed within a larger area of affected groundwater measuring approximately 1,400 feet by 375 feet, or an area of approximately 12 acres. The Site is defined as the area within the outermost borings advanced during the investigation and by the boundary of the Ahern Road—Vernalis site to the northwest. The borings advanced as part of site investigations are shown on Figure 2. The Site includes two inactive petroleum pipeline systems: the former Old Valley Pipeline (OVP) and the former Tidewater Associated Oil Company(TAOC)pipelines,which are collectively referred to as the CEMC Historical Pipeline Portfolio-Bakersfield to Richmond (HPP-BTR). Additionally, an active pipeline owned by Kinder Morgan Energy Partners, LLC (KMEP)is also located within the boundaries of the Site. The KMEP pipeline runs within the Union Pacific Railroad(UPRR) right of way(ROW)along the north side of the tracks and reportedly transports refined petroleum products. The locations of the former OVP and TAOC pipelines,borings, and UPRR ROW are shown on Figure 2. At least 40 years have elapsed since the former OVP and TAOC pipelines were decommissioned, and the plume size has stabilized and may now be shrinking as natural attenuation continues to degrade TPH in soil and groundwater. SAIC performed a Human Health Screening Evaluation(HHSE) in 2012,which demonstrated that constituents of potential concern (COPCs) do not pose a threat to potential residents based on the most conservative exposure scenario (SAIC,2012a; Appendix B.24),and that the Site is therefore suitable for NFAR status. Consistent with State Water Resources Control Board(SWRCB)Resolution No. 92-49, in particular Section IIIA through C, SAIC evaluated available removal technologies and found that all options would be ineffective, infeasible, and costly(SAIC,2005). TPH will naturally attenuate over time to levels below the Water Quality Objective(WQO; Central Valley Regional Water Quality Control Board [RWQCB], 2008). CEMC requests that the Central Valley RWQCB issue an NFAR letter for this low-risk site for these reasons. This report contains the technical data and rationale to support a decision by the Central Valley RWQCB to issue an NFAR letter for the Site. SAIC prepared this report taking into consideration the documentation outlined in Appendix A of the Tri-Regional Recommendations (Central Valley RWQCB, 2004). In support of the NFAR request, this report provides summaries of previous site investigations(Section 2); the documentation requirements outlined in the Tri-Regional Recommendations(Section 3); conclusions and recommendations (Section 4); and a list of references(Section 5). 1 SAIC