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PRIVILEGED & CONFIDENTIAL borings completed inside the bank building, it is Building Analytics' opinion that the USTs no longer exist on-site. CONCLUSIONS ' Building Analytics has completed an additional Phase 11 Subsurface Investigation at the above-referenced site. ' Based on the data presented in this report, the following summary of findings is presented: • The groundwater flow direction was measured to be to the northeast with a hydraulic gradient of 0.0055; • TPH-g concentrations between 1.3 and 590 mg/kg were reported in the soil ' samples collected from Boring B5 at depths between 35 and 61 feet bgs. The deepest sample, B5-78, collected at 78 feet bgs, was reported to contain 2.8 mg/kg of TPH-g; • Only sample B5-50, collected at 50 feet bgs, was reported to contain benzene, at 0.006 mg/kg. • TPH-g and BTEX were not reported in groundwater samples collected from monitoring wells MW-1 or MW-3; • TPH-g was reported in the groundwater samples collected from MW-2 and MW-4 at concentrations of up to 3.4 ppm; • TPH (Carbon Range C8-C44+) was also reported in the groundwater sample collected from N W-2, at a concentration of 2.3 ppm; © Benzene was reported in the groundwater samples collected from MW-2 and MW- 4, at concentrations of 1.2 ppm and I 1 ppm, respectively; • MTBE and other fuel oxygenates were not reported in the soil or groundwater samples collected; and • A review of a historical photograph of the site, historical Sanborn Fire Insurance Maps, and the current concentrations of TPH-g and benzene indicates that the most probable locations of the former USTs were east of the former pump island, near the corner of East Market Street and South Wilson Way, which is beneath the ' current bank building. Building Analytics recommends that this report be submitted to the San Joaquin County ' Public Health Services, Environmental Health Division for their review and response, and that quarterly groundwater monitoring be continued to assess changes in groundwater conditions (i.e., flow direction, gradient and contaminant concentrations) and plume stability. ' 9 1981175-WFB.Stockton Ph.11 and Quart.Groundwater