SITE INFORMATION AND CORRESPONDENCE

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Mr. Joel Weiss October 3, 1996 Page 2 In addition to loading operations at the facility, crude oil was pumped through the Waite- Mendota-Richmond (WMR)pipeline which runs along the Southern Pacific Railroad right of way on the northeast border of the property. Between 1903 and 1935, crude oil was pumped from oil fields in Bakersfield to Chevron's Richmond refinery through the WMR pipeline. During World War II, Bunker-C fuel was pumped from the refinery to distribution points south of Richmond. The WMR pipeline was removed from service in 1958. In 1990 the property owners reported four minor oil seeps on the property. Chevron collected and analyzed the seep material and identified material that resembles San Joaquin Valley crude oil, the same material conveyed by the WMR pipeline. A toxicity characteristic leaching procedure (TCLP) analysis was performed on the seep material, with no analytes detected above the method reporting limit. The TCLP analysis demonstrates that chemicals of concern potentially present in the seep material do not leach under TCLP conditions. These conditions model the natural environment (i.e., rainfall and acidity) and, based on these results, CPL contends that the seep material is non-hazardous and non-leaching (i.e., immobile). The TCLP results are attached to this letter for reference. Soil and groundwater investigations were conducted in 1990, 1994, and 1995. The most recent report submitted to the CVRWQCB is the May 1996 "Results of Additional Site Assessment - Former Chevron Lyoth Loading Station-Tracy, California"prepared by EMCON on behalf of CPL. Table 1 and Figure I (attached)present a summary of soil and groundwater data collected to date and locations of previous sampling efforts. The remainder of this letter presents CPL's proposed approach to further defining the lateral and vertical extent of impacted soil and groundwater and establishing a rationale for site closure. A tentative schedule for planned activities, proposed analyses for soil and groundwater, and a likely approach to site closure are described below. ADDITIONAL SOIL AND GROUNDWATER ASSESSMENT CPL proposes to install one additional groundwater monitoring well due north of existing monitoring well MW-2. The approximate location of the well is presented on Figure 1. The well will be in the railroad right-of-way and will be installed in shallow groundwater to approximately the same depth as other monitoring wells on the property. To assess potential vertical migration of the weathered crude oil,the soil boring will be over-drilled to a depth of approximately 50 feet below grade surface (bgs), a soil and grab groundwater sample collected, and the soil boring backfilled with bentonite to its field-designed terminal depth. The actual depth of the soil boring and placement of the well will be determined in the field. Following installation and development of the new well, a round of groundwater sampling will be conducted to analyze for contaminants of concern in all on-site wells. A Work Plan providing details of the proposed activities will be submitted to the CVRWQCB prior to initiation of any field activities. Following completion of field activities, a report presenting analytical results and recommendations for further actions will be submitted. Table 2 presents a tentative schedule for completing this work and Table 3 presents the analytical regime for soil and groundwater. .