SITE INFORMATION AND CORRESPONDENCE

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SOIL AND GROUNDWATER MANAGEMENT PLAN FORMER LYOTH LOADING STATION 1. INTRODUCTION Science Applications International Corporation (SAIC), at the request of Chevron Environmental Management Company (CEMC), prepared this Soil and Groundwater Management Plan (plan) for the former Lyoth Loading Station site (Site) in Lyoth, San Joaquin County, California. The Site location (San Joaquin County Assessor's Parcel Number 252-070-03) is shown on Figure 1. The purpose of this plan is to act as a guideline that can be referenced if petroleum hydrocarbon- affected soil (affected soil) or petroleum hydrocarbon-affected groundwater (affected groundwater) associated with Chevron Historical Pipeline Portfolio—Bakersfield to Richmond (HPP-BTR) infrastructure are encountered during on-site excavation or dewatering. This plan outlines the roles and responsibilities of CEMC, on-Site contractors, and Mr. Ronald E. Hoffman, et al. or current property owners (property owners). This plan also outlines the procedures and practices for reuse or disposal of affected soil, and discharge or disposal of affected groundwater. The intent of this plan is to provide guidance in the event affected soil and/or groundwater are encountered during incidental excavation on the property. For other projects, such as redevelopment of the property, CEMC should be notified as far in advance as possible so that a project-specific soil management plan can be developed. While CEMC understands that there are no current plans for development or other construction projects, the goal of this plan is to provide information to the property owner on procedures to follow if affected soil and groundwater associated with former HPP-BTR pipeline operations are encountered during small-scale, incidental excavation activities at the Site. CEMC should be notified as soon as practical in the event affected soil is encountered to allow for prompt removal of such soil. A project contact list is provided in Appendix A. 2. BACKGROUND AND HISTORY 2.1 HYDROGEOLOGY Regionally, the Site is located within the Tracy Sub-basin (Groundwater Basin Number 5-22.15), which is defined by the areal extent of unconsolidated to semi-consolidated sedimentary deposits that are bounded by the Diablo Range on the west, the Mokelumne and San Joaquin rivers on the north, the San Joaquin River on the east, and the San Joaquin-Stanislaus county line on the south. The Tracy Sub-basin is located adjacent to the eastern San Joaquin Sub-basin on the east and the Delta-Mendota Sub-basin on the south. These sub-basins are located within the larger San Joaquin Valley Groundwater Basin. The Tracy Sub-basin is comprised of continental deposits of late Tertiary to Quaternary age including the Tulare Formation, Older Alluvium, Flood Basin Deposits, and Younger Alluvium. The thickness of these formations ranges from a few hundred feet in the western foothills to about 3,000 feet near the eastern margin of the basin. The Tulare Formation consists of semi- consolidated, poorly sorted, discontinuous deposits of clay, silt, and gravel. The Corcoran Clay is situated near the top of the Tulare Formation, separating groundwater in the basin in what has been reported as two primary aquifers. The upper aquifer is reported at 15 to 250 feet below ground surface (bgs) and the lower aquifer is reported at 600 feet bgs. Depth to groundwater in 1 Chevron 1W