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No Further Action Required Request Report US Can—Welty Road September 24,2013 The OVP was installed between 1902 and 1904 as a"hot line"(i.e., the oil was heated to facilitate transmission) and carried San Joaquin Valley crude oil(SJV crude)north from the Kern River Oil Fields (in and near Bakersfield)to the Richmond Refinery. The pipeline and associated pump stations operated from 1903 until the early to mid 1930s. The TAOC pipeline system was constructed in 1907 and transmitted heated crude oil from the southern San Joaquin Valley to the Bay Area. For a relatively short time the pipelines transmitted a cutter stock with the crude oil between Coalinga and the Bay Area; the cutter stock was used to reduce the viscosity of the oil. The TAOC pipelines were operated until the 1970s. KMEP operates an active pipeline within the UPRR ROW that runs parallel to the former HPP- BTR pipelines; the KMEP pipeline reportedly transports refined petroleum products. The Site emerged after several unrelated environmental investigations were conducted at Hunter Container. During 1995 and 1996 investigations of a former burn pit and a release from a condensate outlet at the property,petroleum hydrocarbons were encountered in soil and groundwater. As a result, in 1997 CPL initiated investigations of the former HPP-BTR pipelines. The locations of current structures, former underground storage tanks(USTs), excavations, former OVP and TAOC pipelines,borings, and the UPRR ROW are shown on Figure 2. A complete summary of previous environmental activities is included as Appendix A. Supporting documentation,which includes all previous site investigation reports, is included as Appendix B. Historical tables and figures are included as Appendix C. 2. Site geology and hydrogeology The site is located near the western margin of the Central Valley. Underlying this area are interbedded clay, silt, sand, and gravel Quaternary alluvial deposits from the Coast Ranges to the west. Soils encountered at the Site consist of predominantly fine-grained material such as silts and clays,with lesser amounts of coarser-grained material such as sands and gravels. The depth to groundwater generally ranges from approximately 31 feet to 39 feet bgs. Historical data for the Site indicate that the groundwater flow direction is to the east at approximately 0.001 feet per foot(SAIC, 2010; Appendix B.23). Regional groundwater flow-direction information and local topography on the relevant United States Geological Survey(USGS)topographic map also indicates an easterly groundwater flow direction(DWR, 2003; USGS, 1980). 3. Sensitive potential receptors including water supply wells and surface water. An irrigation canal parallels Highway 33 along the northeast side of the highway, southeast of the intersection with South Welty Road. At its closest point, the canal is approximately 30 feet north of hydrocarbon-affected soil and groundwater at Area 1; however, the depth of the canal is relatively shallow(less than 10 feet below grade)and hydrocarbon-affected soil and groundwater identified in this area is greater than 30 feet bgs. SAIC performed a DWR well search in 2010 and a supplemental well search in 2012. Eight water-supply wells were identified within or proximal to a 2,000-foot radius of the Site. (An irrigation well identified outside the 2,000-foot radius was also included due to some ambiguity as to the exact location.) Information on a ninth water-supply well identified during the 2010 well search was removed following the 2012 supplemental well search due to insufficient and conflicting information(SAIC, 2012b; Appendix B.25). 6 SAIC