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Residual fluid had been removed from the tank by pumping it into a vacuum truck. It was then transported to a recycling facility by California Oil Recyclers, Inc., of Newark, California (EPA No. CAD980695761). A copy of the receipt for this transport is included in Appendix A. 2.2 Tank Inspection and Field Observations Observations were made by Levine•Fricke personnel during tank removal regarding sediment types encountered and the occurrence of petroleum in tank backfill and native soils exposed during excavation activities. The former tank location and excavation boundary are shown on Figure 2. A 3 -inch thick asphalt pavement covered the underground storage tank area. Depth to the top of the tank was approximately 3 feet below grade. The tank diameter was 8 feet, so that the tank bottom was at a depth of approximately 11 feet below grade. Appurtenant piping attached to the tank included fill pipes, vent pipes, product pipes, and vapor recovery pipes, as shown in Figure 2. No evidence of leakage or holes was observed in the piping during the inspection. After the tank had been emptied and removed, it was visually inspected. The tank was constructed of steel with welded seams; it appeared in good condition. No evidence of leakage or holes was observed during the inspection. •- Visual observations and organic vapor measurements taken using a field photo -ionization detector (PID) indicated that backfill materials (sand) formerly surrounding the tank did not contain indications of petroleum fuel. PID measurements were generally below 5 parts per million (ppm), and only localized pockets of backfill materials in the vicinity of the dispenser island and a portion of the piping trench contained hydrocarbon odors. PID measurements of these localized pockets ranged from 30 to 100 PPM - Native sediments surrounding the tank backfill materials consisted of very stiff, dark grey, silty clay of high plasticity from the surface (underneath the asphalt -pavement section) to a depth of 4 feet. These sediments graded to a stiff, brown, sandy clay of moderate plasticity to depths of at least 14 feet. Visual inspection and PID readings of these soils did not indicate the presence of petroleum hydrocarbons in native soils } adjacent to the tank excavation or piping, with the exception of those odors in localized areas noted above. These indicators may have been associated with a small -volume release of fluids remaining in the piping when it was disconnected from the -2-