SITE INFORMATION AND CORRESPONDENCE

Home Browse Search

M'. Scott Mansholt - 3 - 10 November 2009 Chevron Banta Road - UPRR, Tracy • The California Natural Diversity Database (2009) maintained by California Department of Fish and Game, was reviewed by SAIC for threatened, endangered, or sensitive species in the vicinity. None have been observed within one mile of the Site. • The ERE findings indicate that exposure to chemicals present in soil at the Site should not result in unacceptable risk for an onsite adult or child resident. ERE results for the petroleum hydrocarbon COPCs do not exceed respective environmental screening levels and thus do not pose a threat to potential future residents, workers, or ecological receptors at the Site. Affected soil occurs at depths greater than 10 feet bgs and thus the exposure pathway is considered incomplete. • SAIC has proposed completion of a request for a No Further Action Required (NFAR) determination for the Site. Based on our review, Central Valley Water Board staff has the following comments: • Consistent with other OVP/TAOC sites, a separate Soil Management Plan (SMP) needs to be prepared and submitted. The SMP designates Chevron as the responsible party and serves as a guideline for Chevron to implement for the handling, reuse, and disposal of any soil affected by the degraded crude oil that may be encountered or excavated during future Site activities. • Central Valley Water Board staff concur with the findings of the ERE and related supporting documentation, and that the Site is a candidate for closure and a request for an NFAR determination may be prepared. Documentation to support a NFAR closure determination should be completed in accordance with California Regional Water Quality Control Board Central Valley Region's 16 April 2004 update to Appendix A of the Tri-Regional Board Staff Recommendations for Preliminary Investigation and Evaluation of Underground Tank Sites - No Further Action Requests. Section 6.3 - NFAR Criteria for Low Risk Vadose Zone Cases should be followed for documenting Site conditions. By 30 March 2010, please submit the documentation to support a request for NFAR determination report. A separate SMP can be submitted at the same time. If you have any questions or comments, please call Dean Hubbard at (559) 445-5179. C �,010 SHELTON R. GRAY C. DEAN HUBBARD Senior Engineering Geologist Engineering Geologist P.G. No. 6357 cc: Harlan Knoll, San Joaquin County EHD, Stockton Karen Fitzgerald, UPRR, Omaha, NE Alfred & Mable Pombo, Tracy Michael Hurd, SAIC, Oakland Michael Jenkins, SAIC, Sacramento