SITE INFORMATION AND CORRESPONDENCE

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US Can-Welty Road -2 - 2 April 2014 No Further Action Required the east-northeast to the UPRR and highway easements and to vacant land a distance of up to approximately 150 to 250 feet. The petroleum hydrocarbons in soil and groundwater have been shown to be stable or shrinking and will naturally degrade over time, likely several years. Chevron submitted a Soil and Groundwater Management Plan (SGMP), dated 11 November 2013, which provides Chevron contact information if future construction or other Site development and/or improvements encounter crude oil impacted soil or groundwater. Average depth to on-site groundwater is about 35 feet below ground surface (bgs) and is not likely to be encountered by routine Site activities. Installation of on-site shallow water-supply wells or in the UPRR and highway easements is unlikely within or in the immediate vicinity of affected groundwater given its poor quality and likely low yield. Affected groundwater is anticipated to remain localized as it slowly and naturally attenuates with time. Human Health and Ecological Screening Evaluation A human health and ecological screening evaluation (HHESE), dated March 2012, used a potential human receptor as the land use risk exposure scenario (considered the most conservative approach) for evaluation of exposure to TPH chemicals of potential concern (COPCs). The HHESE was conducted using a methodology and approach described in the California Environmental Protection Agency (Cal/EPA), Department of Toxic Substances Control, Preliminary Endangerment Assessment (PEA) Guidance Manual, 1999. A total of 77 soil samples from 55 locations collected from between 0 and 10 feet below ground surface (bgs) were analyzed and the results used in the HHESE to evaluate risks and hazards from exposure to COPCs. The consultant estimated the total potential cancer risk to a hypothetical resident from oral, dermal, and inhalation exposure to on-site soils to be 2E-06 (i.e., two in one million). This level of risk is at the lower end of the risk management range of 1 E-06 to 1 E-04 established by Cal/EPA and the US EPA. In conjunction, the same pathway parameters outlined above were used to estimate the non- cancer hazard index (HI) exposure. The total non-cancer hazard exposure to on-site soil was 0.02, which is less than the acceptable HI of 1. This HI indicates that potential exposure to on-site soils would not result in a public health risk. In conjunction with the risk assessment, Chevron's consultant reviewed the 2011 California Department of Fish and Game - California Natural Diversity Database for threatened and endangered wildlife. The assessment indicates that a threat to sensitive ecological receptors does not appear to exist within one-mile of the Site. No Further Action Request Required Chevron submitted the NFAR, dated 24 September 2013, which summarizes the various investigations and the HHESE in support of the no further action request. In addition, Chevron submitted a Soil and Groundwater Management Plan, which provides contact information for Chevron or interested parties if future construction activities encounter crude oil impacted soil or groundwater. As part of the NFAR determination, Staff prepared a Fact Sheet that summarized the assessment activities which have occurred at the Site. The Fact Sheet and a 7 February 2014 notification letter sent to property owners surrounding the Site provided notice of the Central Valley Water Board's