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8720019-1 CON-2 <br /> INVESTIGATIVE AND REMEDIAL ACTIVITIES - <br /> The 5,000-gallon tank was removed by 8 & C Construction on April 30, <br /> 1987. The soils surrounding the tank exhibited evidence of contamination, <br /> especially along the southern end and, as such, required remediation. No <br /> holes or evidence of leakage was apparent from a % -ual examination of the <br /> tank, leading to the assumption that the conta.:iination was a result of <br /> periodic overfillings. The tank was later hauled off for subsequent <br /> cleaning and final disposal . <br /> The contaminated soil around the tank and to the _ --th and southeast was <br /> excavated and aerated as before. Grab samples taken periodically and <br /> field examined for odor and visual evidence of -or.. .-:mination. The loading <br /> dock driveway along the entire southern edge of `fie excavation had been cut <br /> back 15 feet and all the material beneath it removed. In general , the <br /> contamination appeared to be restricted to a narrow zone from slightly <br /> below the water table to 1 to 2 feet above it. The excavation was extended <br /> in all directions until no obvious signs of contamination remained. The <br /> exception to this was along the southern edge near well MW-17, where slight <br /> hydrocarbon odors were still present. The lower extent of the excavation <br /> was approximately 1 foot below the water table, where the previous <br /> excavation found no detectable hydrocarbons. The approximate location of <br /> the excavation is shown in Figure 2. <br /> Following completion of the excavation, four soil samples (E-1 through E-4) <br /> were taken along the perimeter to confirm that most, if not all, of the <br /> contaminated soil had been removed. No samples were taken from the <br /> northeastern portion, as that area was part of the initial excavation and <br /> is now comprised of clean fill. The samples were taken from the sides of <br /> the excavation at the approximate position of the water table, 6.8 feet <br /> below grade. Samples were obtained by pushing a brass tube into material <br /> collected by a backhoe at the locations mentioned above. The tubes were <br /> then sealed with aluminum foil , PVC end caps and tape and placed in cold <br /> -3- <br /> i <br />