ARCHIVED REPORTS_REMEDIAL ACTION REPORT

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Tracy Pump Station Remedial Action Report January 4,2012 Bay Area; the cutter stock was used to reduce the viscosity of the oil. The TAOC pipelines were abandoned in the 1970s_ Two active pipelines,the Kinder Morgan Energy Partners, L.P. (KMEP)pipeline and Chevron Pipe Line Company's Bay Area Products Line(BAPL), are also located within the UPRR ROW. The KMEP and BAPL pipelines transport refined petroleum products. 2.3 EXISTING AND PLANNED DEVELOPMENT The Site is located in an agricultural area in Tracy, California. The western portion of the Site is an agricultural field. A windmill-turbine repair shop and a cabinet-and-door manufacturing shop are currently located on the northeaster portion of the Site. The southeastern portion of the property is used as cattle pens. There are no knownplans for site redevelopment or changes inland use. 2.4 HYDROGEOLOGIC SETTING The Site is located within the San Joaquin Valley Groundwater Basin. This basin is divided into nine sub-basins. The Site lies 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 bounded by the Diablo Range to the west, the Mokelumne and San Joaquin rivers to the north, the San Joaquin River to the east,and the San Joaquin-Stanislaus county line to the south. The ' Tracy Sub-basin is adjacent to the eastern San Joaquin Sub-basin to the east and the Delta-Mendota Sub-basin to the south. The Tracy Sub-basin is comprised of continental deposits of late Tertiary to Quaternary age, Iwhich includes 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 into what has been described as two primary aquifers. The upper aquifer is reported at 1 15 to 250 feet below ground surface(bgs), and the lower aquifer is reported at 600 feet bgs. The Site's location within the sub-basin indicates that it is likely immediately underlain by Younger Alluvium, Older Alluvium, and/or Flood Basin Deposits. Groundwater has been observed at the Site at approximately 4.5 to 16.5 feet bgs (California Department of Water Resources, 2006). 2.5 PREVIOUS ENVIRONMENTAL ACTIVITIES SAIC performed several environmental investigations at the Site under the direction,and to the satisfaction, of the Central Valley RWQCB. SAIC prepared a RAP for PAH-affected soil removal in June 2011. A summary of previous site investigation activities and results are included as Appendix B. 3. SITE REMEDIATION ACTIVITIES SAIC implemented the recommendations presented in the RAP as described in sections 3.1 through 3.4. 2 SAIE