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and Nilsen, 1990). Data from nearby studies within the Port area indicate a soil profile to a depth of about 20 feet bgs comprised of interbedded sands and clays, mostly under reduced conditions°(Sierra-Pacific Groundwater Consultants [SPGC], 1994). Lithologic data from boring B5-1 (Appendix A) indicate the lithology in the vicinity of the former USTs comprises mostly fine- to very fine-grained sand and silty sand to a depth of about 17 feet bgs, with silt and clay predominate from about 17 to 28 feet bgs, the maximum depth explored at the site. Soils encountered near the former dispenser area (borings.B5-4 and B5-5) comprise mostly clay. A 1- to 2-foot thick bed of sand occurs beneath the former dispenser area at about 17 feet bgs (Appendix A). Data from nearby studies indicate that the current depth to groundwater in the vicinity ranges from about 5 to 10 feet bgs (SPGC, 1998, and EMCON, 1998). Seasonal fluctuations in the water table appear to range from about 3 to 5 feet, with some as much as 6 to 9 feet. Tank removal inspection records for this and other Port sites (dating back to 1987) indicate that no groundwater was encountered during excavation of tanks or soil resampling to a depth of as much as 16 feet bgs. Water levels in this area have risen as much as 8 feet since 1994, 2 to 3 feet of which appear to be attributable to the heavy and prolonged El Nino rainfall events of last winter. The static water level in the borings emplaced near the former USTs (borings B5-1 to -3) was,'about 9 feet bgs on August 5, while water levels in the borings emplaced near the former dispenser area (borings B5-4 and -5) were about 1l.feet bgs (Appendix A). Based on nearby studies (SPGC, 1998, and EMCON, 1998) groundwater flow directions in the vicinity appear to be variable, ranging from west northwest to east southeast. Flow direction changes may be due to tidal influences produced by the deep water channel to the north and the San ` Joaquin River to the west and southwest of the Port area. 4.2 SOIL AND GROUNDWATER ANALYTICAL RESULTS Analytical results for soil and groundwater samples collected during this investigation are presented on Table 2. The laboratory data sheets and chain-of-custody records are included in Appendix B. No PHCs were detected in soil samples collected near the former USTs in borings B5-1 through B5-3. However, the groundwater sample collected from boring B5-1, along the eastern side of the former UST excavation, contained BTEX constituents and 4.2 I mg/f TPHg. Trace amounts of benzene (0.005 mg/kg) and toluene (up to 0.015 mg/kg) were detected in soil samples collected in boring B5-5 near the former dispenser area. No PHCs were detected in the soil samples collected in boring B5-4. However, groundwater in the f vicinity of the former dispenser is impacted with PHCs. Groundwater samples collected from borings B5-4 and B5-5 contained BTEX constituents (up to 0.46 mg/f xylenes and 0.035 mg/f benzene) and up to 1.1 mg/P.TPHg. The laboratory included a note on the analytical results for water samples W-007 and W-008, collected from boring B5-4, stating "Chromatography 1 6 "117WgVRPrSWUSTMV.RPr