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KEI-P89-1104 .R9 December 17 , 1992 Page 7 (designated as EB1 through EB7 on the attached Figure 1) were drilled at the site. Subsurface materials penetrated and the depths at which soil samples were collected are shown in the attached Boring Logs. The seven borings were drilled to depths of 10 to 59 feet below grade. Ground water was encountered at depths of 58 . 0 to 58 . 5 feet below grade in exploratory borings EB1 through EB4 . In exploratory borings EB5 through EB7 , which were drilled to total depths of less than 58 feet below grade, ground water was not encountered during drilling. In addition, exploratory boring EB7 was drilled at an angle of 10 degrees to the vertical . Soil samples were collected at a maximum spacing of 5 fdot intervals, at significant changes in lithology, at obvious areas of contamination, and at or within the soil/ground water interface, beginning at a depth of 5 feet below grade in each of the borings, with the exception of EB5 and EB6 , where samples were collected beginning at 4 feet below grade. In addition, only three soil samples from EB7 were submitted for laboratory analysis . The undisturbed soil samples were collected by driving a California-modified split-spoon sampler ( lined with brass liners) ahead of the drilling augers . Exploratory borings EB5 and EB6 were drilled and sampled by the use of a hand auger The clean, two-inch diameter brass liners holding the samples were then sealed with aluminum foil , plastic caps and tape, labeled, and stored in a cooled ice chest for delivery to a state-certified laboratory. Drilling was stopped about 0 . 5 to 2 feet after intersecting the first water table . Water samples were collected from borings EBI through EB4 by the use of a clean acrylic bailer The water samples were decanted into clean VOA vials and/or one- liter amber bottles, as appropriate, which were then sealed with Teflon-lined screw caps, labeled, and stored in a cooler, on ice, for delivery to a state-certified laboratory After the water samples were collected, the borings were backfilled to the surface with neat cement grout ( in accordance with the grout mixing guidelines presented in the California Well Standards , Bulletin 74- 90, dated June 1991) . Bentonite was used to seal the borings within the saturated zone. Grout was placed from the bentonite plug up to the surface in one continuous pour. ANALYTICAL RESULTS -- EXPLORATORY BORINGS All samples were analyzed at Sequoia Analytical Laboratory in Concord, California, and were accompanied by properly executed Chain of Custody documentation. Water and selected soil samples from all seven exploratory borings were analyzed for TPH as gasoline by EPA method 5030/modified 8015 , and BTX&E by EPA method 8020 . In addition, water and selected soil samples from EB3 and EB4 were analyzed for TPH as diesel by EPA method 3550/modified