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Limited Phase II Environmental Site Assessment United Storage 2115 West Washington Street Stockton, California Delta Project No. A002-124-1 Page 6 4.3 Soil Analytical Results As part of this Limited Phase ll ESA, ten soil samples were submitted for laboratory analyses. The laboratory report is provided in Appendix C. Soil analytical results for parameters detected in at least one sample are summarized in Table 1. VOCs, methyl tertiary-butyl ether (MTBE), and TPH were not detected at or above the respective laboratory detection limits in any of the soil samples. Six of eight RCRA metals were identified in at least one soil sample at concentrations above the respective laboratory detection limits. Cadmium and silver were the only metals that were not detected in the soil samples. The highest concentrations of each metal were detected in sample B1-12: 8.91 milligrams per kilogram (mg/kg) arsenic, 250 mg/kg barium, 41.8 mg/kg chromium, 10.6 mg/kg lead, 0.321 mg/kg mercury, and 0.883 mg/kg selenium. 4.4 Soil Regulatory Criteria The EPA Region 9 Superfund Program has established Preliminary Remediation Goals (PRGs), which are risk-based concentrations used for evaluating and cleaning up contaminated sites. PRGs are not legally enforceable standards, but may be used as initial cleanup goals. Soil analytical results obtained during this investigation were compared against the PRGs for industrial soils. The PRGs for contaminants identified at the subject property are provided in Table 1. Arsenic was detected in all ten soil borings at concentrations exceeding the PRG of 1.6 mg/kg. Mercury was detected in B1-12 and B10-12 at concentrations of 0.321 and 0.102 mg/kg, respectively, higher than the PRG of 0.0 mg/kg mercury. 4.5 Ground Water Analytical Results Ground water samples (W-B2, W-B5, W-B7, W-B8, and W-B9) were collected from five of the soil borings and submitted for laboratory analyses. The laboratory report is provided in Appendix C. Ground water analytical results for parameters detected at or above the detection limit in at least one sample are summarized in Table 2. VOC and TPH-G were not detected at or above the respective laboratory detection limits in any of the ground water samples. MTBE was detected in W-B7 at a concentration of 13 micrograms per Liter (pg/L). TPH-D was detected in W-B8 and W-B10 at concentrations of 1,100 and 470 pg/L, respectively. eAwestwayterminalcota002124 \1-stockton, catdocs \stockton phase ii report.doc