ARCHIVED REPORTS_PHASE II ENVIRONMENTAL SITE ASSESSMENT

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W GIK Sounthwesit, IImto. established for petroleum hydrocarbons, Environmental Screening Levels (ESLs) for the San Francisco RWQCB are listed for these constituents. All of the CAM17 metals were detected in at least one of the soil samples. However, most concentrations were below the PRGs and TTLCs. Exceptions were the lead and/or zinc concentrations in the one-foot samples from B-3, B-4, B-6, B-8, B-9, B-13 and B-16, which ranged from 1,000 to 19,000 mg/Kg for lead and 5,200 to 29,000 mg/Kg for zinc. These concentrations met or exceeded the TTLC limits of 1,000 mg/Kg for lead and 5,200 mg/Kg for zinc, categorizing these soils as hazardous waste. The highest lead and zinc concentrations were found in the one-foot sample from B-13, which also contained concentrations of antimony, chromium and copper exceeding the TTLC limits. B-13 was located in the central portion of the site near the railroad spur. Arsenic concentrations in all of the soil samples were between the PRG of 1.6 mg/Kg and the TTLC of 500 mg/Kg. Excluding the highest arsenic concentration of 88 mg/Kg which was detected in the one-foot sample from B-13, arsenic concentrations ranged from 2.3 to 41 mg/Kg. Detectable concentrations of PCBs exceeding the PRG of 0.74 mg/Kg but not the TTLC of 50 • mg/Kg were found in one-foot samples from B-1, B-3, B-4, B-6, B-9, B-10, B-12 and B-13. The concentrations ranged from 3.8 to 9.9 mg/Kg, with the highest level detected in B-13. Specific PCBs detected were Aroclor 1016, 1232, 1242, 1248 and 1254. Figure 3 graphically illustrates the detectable PCB concentrations found in the soil and groundwater samples. The one- and three-foot soil boring samples were analyzed for petroleum O&G. Detectable concentrations were found in all 18 borings except B-11 and B-18 at levels ranging from 73 to 10,000 mg/Kg with the highest concentration detected in B-9. B-9 was located near the existing AST and location of the former USTs. O&G concentrations in excess of the ESLs were detected in one-foot samples from B-1, B-4, B-6, B-9, B-10 and B-13. TPH as motor oil (TPH-mo) was detected in the one-foot soil samples from all borings except B-11 and B-18 at concentrations ranging from 9.8 to 1,800 mg/Kg with the highest concentration in B-9. All of these concentrations were below the ESL. An additional sample was collected at three feet bgs in B-8 because a degraded petroleum odor was noted at that depth during drilling. B-8 was located near the hazardous materials storage area, and the three-foot sample contained a concentration of TPH-mo of 560 mg/Kg; the one-foot sample had a concentration of 97 mg/Kg. The only five-foot sample with detectable TPH-mo was 704. PRI.05 21 July 21, 2008