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3.0 SOIL INVESTIGATION Three borings were drilled on September 9, 1994 (Figure 2).' V& W Drilling of Rio Vista, California provided a truck-mounted Mobile:Grill B-53 drilling rig and crew. Soil samples were collected at 5-foot intervals using a California modified split-spoon sampler loaded with three -- brass sample sleeves. The bottom sleeve was preserved for laboratory analysis by covering the ends with teflon sheets and plastic caps and sealing with duct tape. Soil was extruded from the middle and upper sleeves into a plastic bag and screened for the presence of volatile organic hydrocarbons, using a Photovac Microtip ISI",-2000 photo-ionization detector. PID readings and soil descriptions were then recorded on the boring logs(Appendix A). Borings LA-1 and LA-2 were terminated at a depth of 25 feet, and LA-3 was terminated at 30 feet. All borings were backfilled withrgrout in accordance with county regulations. Drill cuttings from the borings were stored on plastic sheeting. ►• The soil samples were transmitted under chain-of-custody to Matrix Environmental Laboratories in Rancho Cordova. All twelve samples were analyzed for the presence of oil and grease, and nine were analyzed for total petroleum hydrocarbons in the gasoline and diesel ranges (TPH-g and TPH-d)and benzene,toluene, ethylbenzene, and.xylene (BTE&X compounds) (Appendix B). Three samples were also analyzed for halogenated hydrocarbons. Per approval from Mr. Sasson, no samples were analyzed for:petals because of the lack of any evidence of contamination in any of the samples. 4.0 RESULTS Silty sand, varying from medium brown to yellowish or reddish brown in color, is present in all three borings from.the surface to a depth of approAmately 25 feet. The sand is slightly damp to 1� dry and ranges from loose to slightly consolidated. No hydrocarbon odors were noted in any,of the samples, and PID readings were ver, low, ranging from background levels of 4 pprn up to 13 —0 ppm in sample LA-3-15'. One sample obtained at the 20' level from LA-2 detected hydrocarbons (Appendix B). Laboratory daia from LA-2-20' showed a concentration of 5 . ppm TPFI••gasaline, .0084 ppm Benzene, .036 ppm. Toluene, .021 ppm Ethylbenzene and .23 ppm Xylene. No oil & grease or diesel was detected from the same sample.