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detected in any of the soil samples, and most PHCs (maximum of 120 mg/kg TPHg)were detected along the west side of the excavation, beneath Tank#4. A total of 9 soil samples were collected by Canonie Environmental about every 20 linear feet along the pipeline at a depth of approximately 3 feet bgs. Soils beneath the dispenser were also sampled. Soils beneath the pipeline and dispenser were described by PHS/EHD as"loam and rock,""red," "black," and"gray clay," and"adobe clay with sand." Gray discolored soil and petroleum product ,r odor were reported in the pipeline sample nearest the dispenser and in the sample beneath the dispenser itself. PHCs were detected in four of nine samples collected along the pipeline. Trace amounts of toluene,xylene, and ethyl benzene were detected in the sample approximately 120 feet west of the former tanks. Higher levels of PHCs,including 0.55 mg/kg benzene and as much as 140 mg/kg TPHg,were detected near and beneath the former dispenser island where discolored soil and petroleum odors were detected during the pipeline removal. r 2.2.2 Initial Subsurface Investigation Analytical results indicated 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 constituent and de mg/ 9 TPHg. Trace amounts of benzene(0.005 mg/kg) and toluene(up to 0.015 mg/kg) ed in soil samples collected in boring B5-5 near the former dispensea nater in he vir area, No cinity of the former in the soil samples collected in boring B5-4. However, grouCs were detectedp dispenser is impacted with PHCs. Groundwater samples les collected from borings B5-4 and B5-5d 0.035 mg/Q benzene) and up to 1.1 mglQan contained BTEX constituents(up to 0.46 mglQ xylen TPHg, n from 5.8 to 12 mg/kg in soil samples from each Total lead was detected at concentrations rangi g of the five borings drilled at the site. No lead was detected in the groundwater samples. These lead concentrations were found to be within background levels for the area. +� 2.3 GEOLOGIC AND HYDROLOGIC CHARACTERISTICS The site is located on the delta of the San Joaquin River, approximately 2 miles east of the confluence of the San Joaquin and Calaveras Rivers. The subsurface geology consists oio of ck ca overlying sedimentary sequence of alluvial deposits of late Tertiary to Holocene Age, overl g (Bartow and Nilsen, Cretaceous to Tertiary age, which in turn overlie crystalline basement rocks (B � 1990). Data from nearby studies within the Port area in a soil profile to a depth of about 20 feet bgs comp rised of interbedded sands and clays, mostly under reduced conditions(Sierra-Pacific r 1994). Lithologic data from baring B5-1 indicate the lithology Groundwater Consultants[SPGC], 3 PHILIP P. ROSS,R.G. +� .s.aaiFLV.WPn 4..