SITE INFORMATION AND CORRESPONDENCE

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No Further Action Required Determination - 3 - 6 January 2011 Banta Road-UPRR Tracy-Fresno Line Tracy, San Joaquin County also submitted for general minerals analysis for water quality evaluation. The analytical results for TPHd were ND for two samples and 55 micrograms per liter (pg/L) for the third, which is less than the screening level of 100 pg/L considered protective of human health. Analytical results for BTEX and PAH compounds were ND. • Based on the findings, in September 2009, SAIC submitted an environmental screening evaluation to evaluate potential risk to human health. According to the report, concentrations of the petroleum hydrocarbon compounds considered to be chemicals of potential concern detected did not exceed respective environmental screening levels and thus do not pose a threat to potential future onsite residents, construction/trench maintenance workers, or ecological receptors. A conservative approach based on a residential scenario was utilized in the screening evaluation, but the most likely current and future Site use will be for construction/trench maintenance activities within the highway right-of-way and/or the railroad tracks. • A 10 November 2009 Central Valley Water Board letter to Chevron stated that based on the findings, crude oil affected soil and groundwater were defined, the site was a candidate for closure, and a request for No Further Action Required determination could be prepared. • SAIC reviewed the 2009 California Natural Diversity database, maintained by the California Department of Fish and Game, to search for threatened, endangered, or sensitive species in the vicinity of the Site. None were identified within one mile of the Site. Plans for development of the Site are not likely considering the location within the highway easement. • In March 2010, SAIC provided a Soil and Groundwater Management Plan (SGMP) for the Site. The SGMP designates Chevron as the as the responsible party for any issues that may arise related to the crude oil leaks encountered during future site excavation and/or maintenance activities. • SAIC provided a No Further Action Required Request Report (NFAR) for Site closure dated 9 March 2010. • On 16 November 2010, Central Valley Water Board staff provided notification to the owner(s) of properties overlying and/or within 200 feet of the approximate boundary of affected soil/groundwater defined at the Site. The notification stated that the Central Valley Water Board was considering a No Further Action Required determination for the Site and requested comments be submitted. No comments were received. Extent defined: Yes Estimated Residual Petroleum Mass: Unknown. Petroleum occurs in soil and groundwater as degraded crude oil at/near the former pipelines; analysis of soil samples collected from the maximum depth drilled were ND for TPH compounds. Threat to Groundwater: The historical crude oil pipelines were removed from service more than 35 years ago. The lateral downgradient extent of crude oil affected groundwater has been defined and is limited in extent and contained within South Banta Road right-of-way easement. There are no water wells at the Site and it is unlikely that new groundwater wells will be installed next to/within the highway right-of-way easement.