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1 nearby studies within the Port area indicate a soil profile to a depth of about 20 feet bsg consisting of Interbedded sands and clays, mostly under reduced conditions (Sierra-Pacific Groundwater Consultants [SPDC], 1994) Lithologic data at Site 3 indicate that, in general, the interval from roughly 13 to 23 feet bsg beneath the former tanks comprises mostly silt, clayey silt, and clay Silty sand occurs below this interval, which grades downward into loose, dark gray to greenish-gray, poorly-graded sand This dark gray ' sand was observed in all three borings from approximately 30 to 41 feet bsg,the total depth explored Data from nearby studies indicate that the current depth to groundwater in the vicinity ranges from about 5 to 10 feet bsg (SPDC, 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 Port sites (dating back to 1987) indicate that no groundwater was encountered during ' excavation or soil resampling to a depth of as much as 16 feet bsg 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 Nmo rainfalls the winter of 1997 Water levels measured in the three initial borings at Site 3 on August 7, 1998 ranged from about 9 5 to 12 feet bsg Based on nearby studies (SPDC, 1998 & 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 complex RISTORY OF SITE WORK 1 Two underground storage tanks (USTs) were removed from the site on February 16, 1988 They consisted of two, 12,000-gallon capacity, steel, USTs, which both contained unleaded gasoline Upon removal of the USTs, discolored gray soil and strong petroleum product odors were detected at the ' southern ends of both tanks Minor petroleum product odor was detected at the north end of Tank#1, while no odor was detected at the north end of Tank#4 ' Four soil samples were collected by `California Water Labs' (CWL) from the ends of the USTs subsequent to excavation on February 16, 1988 from a depth of approximately 13 feet bsg No groundwater was encountered during excavation or sampling ' Four additional soil samples were collected b CWL on March 15 1988 These samples were P Y p collected from the same locations as during the tank pulls,but from a depth of 16 feet bsg A review of ' the SJCEHD inspection report indicates that the inspector found "gray soil observed on all samples with petroleum-hke odor" The report also notes that no groundwater was encountered to a depth of ' 16 feet bsg Soil samples collected from beneath the tanks were submitted to CWL for analysis All soil samples were analyzed for total petroleum hydrocarbons as gasoline (TPHg) and total petroleum hydrocarbons as diesel (TPHd) by EPA method 8020 Selected samples were analyzed for ethylene ' dibrotmde (EDB) by EPA method 8010, and total lead Analytical results indicated low levels of petroleum hydrocarbons (PHCs) detected in the initial soil samples, primarily in the samples collected at the south ends of the tanks where petroleum product odor was detected However, PHC ' concentrations in the follow up samples collected approximately 5 feet below the initial samples, were -t 51te3 gtra dm 2 1