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25 March 1996 AGE-NC Project No. 95-0168 Page 2 of 4. 2.3. EXCAVATION OF HYDROCARBON-IMPACTED SOIL On 17 August 1995, hydrocarbon-impacted soil was removed from the former Tank 93 area under the supervision of EnviroSearch of Bakersfield, California. Excavation procedures were directed by representatives of AGE. Six soil samples were collected from the floor and sidewalls of the excavation by AGE. Analytical results of soil samples indicated that hydrocarbon-impacted soil remained in place at the eastern wall of the excavation at a depth.of 14 feet. Further site assessment was requested by the PHS-EHD. 2.4. GROUND WATER DEPTH AND FLOW DIRECTION According to the San Joaquin County Flood Control and Water Conservation District map titled Lines of Equal Depth of Water Wells - E'all 1993, ground water depth in the area of the site is approximately 60 feet below surface grade (bsg). Regional ground water flow direction in the area is westerly. 3.0. SCOPE OF WORK 3.1. DRILLING AND SAMPLING The PHS-EHD is requiring further investigation of the site to determine the vertical and lateral extent of hydrocarbon-impacted soil. AGE proposes to advance two soil borings at the site. Each boring will be advanced at an angle of approximately 25' from vertical. One boring will be advanced beneath the building from the southern edge of the building; a second boring will be advanced beneath the building from the western edge of the building. Borings will be advanced to depths of approximately 20 to 25 vertical feet, utilizing a truck mounted, hollow stem drill rig and 8.25-inch hollow-stem augers. Soil samples will be collected at five-foot intervals beginning at 5 feet bsg in each boring. Samples will be collected using a California split-spoon sampler and brass sleeves. Samples will be driven by dropping a 140-pound weight from a height of 30 inches. The number of blows required to drive each 6-inch length of the sampler (blow counts) will be recorded on boring logs by an AGE staff geologist. Upon sample retrieval, the middle brass sleeve will be removed from the sampler. The ends of the sleeve will be immediately covered with Teflon tape or aluminum sheets, sealed with plastic end caps, secured with tape and immediately placed under ice in a chilled container for transportation to a State-certified laboratory. Each soil sample sleeve will be labeled with the following: boring location, vertical depth, time, date and sampler's initials.