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Mr. Steve Sasson Protect 22794-100.001 August 10, 1998 Page 2 No water well, deeper drinking water aquifers, or other sensitive receptors are likely to be impacted The site represents no significant risk to human health and safety. Site characterization activities defined the extent of soil inVacts and demonstrated the site was a "groundwater i npact" case. Site remediation consisted of UST removal and overexcavation and disposal of approximately 1,200 cubic yards of petroleum hydrocarbon-impacted soil. A previous risk assessment demonstrated that the site no longer represents a threat to human health. Statistical evaluation of groundwater monitoring data shows there are no increasing concentration trends, suggesting the dissolved petroleum hydrocarbon plume is stable The following sections summarize activities conducted to date and present information consistent with low-risk closure criteria This report has been prepared consistent with SJCPHS Interum Guidance on Required Cleanup at Low-Risk Fuel Sites and Appendix B of the Tri-Regional Board staff's Recommendations for Prelindriaiy Investigation and Evaluation of Underground Tank Sites- Requests for Closure. • BACKGROUND Prior to Safeway involvement, the property was condemned for war housing by Court Order No. 4804 rendered on November 8, 1943 Krazan (Phase i Environmental Site Assessment October 13, 1995) reviewed historical air photos that showed the presence of the military housing in 1952 and in 1963. Safeway constructed the meat packing facilities and installed the four 12,000-gallon USTs in 1973. Four 12,000-gallon USTs used to store diesel fuel were removed from the site in July 1987. The former UST locations are shown on Figure 2. Site assessment and groundwater monitoring activities conducted between 1987 and 1995 established the extent of soil impacts and identified groundwater impacts Impacts consist of total petroleum hydrocarbons as diesel (TPHD). Detected TPHD concentrations range from 4 to 3,700 milligrams per kilogram (mg/kg). Benzene, toluene, ethylbenzene, and xylenes (BTEX) constituents were generally below method reporting limits for soil and were not detected in groundwater samples. The highest detected benzene in soil was 0.002 mg/kg. By September 1988, approximately 1,200 cubic yards of petroleum hydrocarbon- impacted soil were removed from the former UST location. Overexcavation activities focused on the southwest corner of the former UST location and were conducted to approximately 24 feet below ground surface (bgs) Excavation was terminated vertically . at the practical depth limits and laterally by the proximity to Navy Drive. SACw\PJ2\2.794\27941000 ICS-99Vwsmer8 Mon Rev 0,8/10198