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necessary protocols for compaction with the backhoe bucket were defined prior to compacting <br /> the backfill within the excavation The test cell was tested by a certified engineer using a <br /> nuclear density gauge. Verification testing was performed within the pit from approximately <br /> four feet to one foot below grade <br /> The backfill was compacted to a depth of approximately 12 inches below grade A PVC <br /> geomembrane was set on top of the compacted fill and extended over one foot beyond the <br /> excavation in all directions. A six-inch cluck aggregate base rock (Class A/B) was then <br /> compacted over the geomembrane followed by a six-inch thick hot asphalt cover that was <br /> poured to seal and restore the surface (Appendix A) <br /> 2.3.5 Sol! Disposal <br /> Based on the analytical results, the excavated soil was hauled to a Class II landfill for <br /> disposal. Photo-documentation of the soil loading is provided in Appendix A. The soil was <br /> transported under non-hazardous waste manifests by certified drivers to Forward Landfill, <br /> located in Manteca, California. Appendix D provides copies of the non-hazardous waste <br /> manifests. <br /> 3.0 Results <br /> 3.1 Site Geology <br /> The soil encountered during the excavation activities was predominantly silt with varying <br /> quantities of clay and sand. At a depth of approximately ten feet below grade a relatively <br /> hard, laterally discontinuous cemented sand unit, approximately four inches thick, was <br /> encountered. The soil was visibly stained and yielded a detectable petroleum odor <br /> 3.2 Soil Results <br /> Seven soil samples were collected from the sidewalls and the bottom of the excavation, as <br /> directed by the County REHS Figure 3 illustrates the sampling locations and Table 1 <br /> presents a summary of the analytical results for the soil samples. No TPH as gasoline or <br /> benzene were detected in any of the samples collected TPH as diesel was detected in all the <br /> samples collected, in concentrations ranging between 150 milligrams per kilogram (mg/Kg) <br /> and 6700 mg/Kg. Toluene was detected in five samples, with concentrations ranging between <br /> 0.47 mg/Kg and 0.93 mg/Kg; ethyl benzene was detected in two samples, with concentrations <br /> MZJ06-23/95/VDBF/95-0007 6 <br />