SITE INFORMATION AND CORRESPONDENCE

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r M. Scott Mansholt -2 - 16 April 2009 F�ormer�yoth Loading Station the site conditions limit most forms of remediation such as pumping and extraction. With time, natural attenuation will reduce the concentrations of residual petroleum hydrocarbons. Central Valley Water Board staff informed Chevron by letter in July 2005 that soil and groundwater had been adequately delineated onsite but not offsite. Offsite crude oil related groundwater conditions are being addressed separately. At our request, Chevron submitted an addendum to the previous HRA in consideration of the current and anticipated future site use. Specifically, the addendum considered potential direct exposure to crude oil affected soil and/or groundwater by future commercial/industrial workers and construction/trench workers. In support of the previous documentation for NFAR consideration, SAIC reviewed the California Natural Diversity Database (California Fish and Game, 2008) to evaluate if threatened, endangered, or sensitive species were present on or in the vicinity of the Site. According to the database search, the onsite occurrence of these species was unlikely and the closest sighting was approximately two miles from the Site. Based on our review of the project files, Central Valley Water Board staff has the following comments: • According to project file documentation, the current and anticipated Site use is, and unless changed, will remain for commercial and/or industrial purposes by the Hoffman's Brothers Harvesting business. • OEHHA staff review of health risk assessment documents determined that the "...theoretical lifetime cancer risk...is within an acceptable risk range...for an assumed residential-setting scenario." • SAIC's recent HRA addendum Report indicated that potential exposure to residual petroleum hydrocarbons remaining at the Site "...do not pose an unacceptable threat to future commercial/industrial workers or construction/trench workers." • There is no record of a threatened, endangered, or sensitive species sighting within two miles of the Site. • Consistent with other Chevron OVP projects, a Soil Management Plan (SMP) specific to the Site needs to be submitted. The SMP will serve as a guideline for Chevron to implement for the handling, reuse, and disposal of any crude oil affected soil and/or groundwater that may be excavated or encountered by the present or future owners at the Site. Based on the technological evaluation and consistent with State Water Resources Control Board Resolution No. 92-049, SAIC's alternative cleanup alternatives concluded there is no known feasible cost effective means, or easily implemented process to effectively remove the petroleum hydrocarbons identified on the Site. In addition, OEHHA's review of the health risk