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6 November 1995 AGE-NC Project No. 95-0120 Page 2 of 5 On 10 and 11 May 1993, approximately 500 cubic yards of contaminated soil was removed from tank pit # 1. Soil was removed from the excavation to a depth of 35 feet from the southern end of the excavation. On 12 and 13 May 1993,the excavation was partially backfilled. Crushed rock and pea gravel were used to backfill the southern portion of the excavation. The entire excavation was then backfilled and compacted to a depth of five feet below surface grade(bsg). From 3 to 5 November 1993,five additional soil borings were advanced at the site. Borings B 10 and B 11 were placed in the area of the excavation, and advanced to depths of approximately 75 and 70 feet, respectively. Three other borings were advanced around the excavation area to 88 feet bsg and completed as 2-inch diameter ground water monitoring wells (MW1 -MW3). Hydrocarbon odors were noted in soil samples from borings B 10, B 11, and MW 1 at depths between 45 and 65 feet. Laboratory analysis detected TPH-g and volatile aromatics in five of the fourteen samples analyzed. 2.3. GROUND WATER DEPTH Ground water beneath the site occurs at a depth of approximately 70 feet below site grade (bsg). The uppermost ground water flows in an unconfined aquifer. With depth, the aquifer becomes more confined due to the presence of mixed heterogeneous layers of sediments. Based upon historical data obtained from on-site monitoring wells, ground water flow direction at the site is to the northeast. 3.0. SCOPE OF WORK 3.1. DRILLING AND SAMPLING The proposed investigation includes the advancement of three soil borings to depths of approximately 65 feet below surface grade (bsg). Two of the borings will be cluster-completed as soil vapor extraction wells. Well design is illustrated in Figure 3. Soil samples will be collected at five-foot intervals beginning at 10 feet below site grade(bsg)using a California split-spoon sampler and brass sleeves. The middle brass sleeve will be removed and the ends covered with Teflon tape or aluminum sheets, sealed with plastic end caps, secured with tape, and immediately placed in a chilled container for transportation to a State-certified laboratory. Each sample sleeve will be labeled with the following: boring location, depth, time, date and sampler's initials.