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CHEVRON/Stockton <br /> May 1987 <br /> SOIL WRINGS <br /> The purpose of the soil borings was to explore the site for <br /> the presence of subsurface hydrocarbon constituents and to obtain <br /> a preliminary definition of the vertical and areal extent of the <br /> constituents, should any be found. Chevron USA requested that <br /> three borings be drilled and monitoring wells be installed if <br /> groundwater was encountered . The three borings were located <br /> around the tank pit excavation (see Figure 2, Site Plan) . Soil <br /> boring 1 was drilled to a total depth of 50 feet, borings 2 and 3 <br /> were drilled to 52 feet below grade. <br /> All of the borings were drilled with a truck mounted drill <br /> rig using 7 . 5-inch O. D. ( outside diameter) hollow stem augems . <br /> The drilling was performed under the supervision of a geologist <br /> who also maintained a continuous log of the materials encountered <br /> (see Appendix I, Drill Logs) . <br /> m� <br /> SOIL SAMPLING <br /> Soil samples were obtained at 5-foot intervals beginning at <br /> 5 feet below grade to the bottom of the borings . Samples were <br /> obtained during drilling using a 2 . 5 inch O.D. split spoon sampler <br /> lined with three 2 x 6 inch brass sample tubes. The sampler was <br /> driven IS inches ahead of the augers at each sample paint . The <br /> collected samples were sealed, capped and packed on ice in an <br /> insulated cooler for subsequent delivery to the laboratory for <br /> analysis. Each sample was labeled with the boring number, sample <br /> number and depth of sample . Soil sampling was conducted in <br /> accordance with Groundwater Technology' s Standard Operating <br /> Procedures (SOPS) 11 , 14 and 15 (see Appendix 1I ) . <br /> - 5 -- <br />