Laserfiche WebLink
11171cot November 11, 1986 <br /> AGS Job #8696-1 <br /> The results of laboratory analyses indicate that soil <br /> contamination exceeds 1,000 ppm in an area including the base of <br /> the tank excavation at its east end, corresponding to sample S1. <br /> S1 was taken at a depth of approximately 14 feet. Sample S2, <br /> which shows low levels of hydrocarbon contamination, was <br /> collected at a depth of approximately 12 feet, to the east of S1 <br /> and under the edge of the excavation. Low levels of total <br /> hydrocarbons in soil samples collected from borings are <br /> consistant with limited migration of contaminants. <br /> Groun%� water has been affected by contamination, probably as a <br /> result of the fuel leaks, such as over filling, that occurred <br /> while the removed tank was in operation. The levels of benzene <br /> and other hydrocarbon constituents detected in water samples from <br /> MW-1 are in excess of accepted safe drinking water standards. <br /> Applied GeoSystems recommends that the tank cavity be further <br /> excavated at its east end, in the area of soil sample S1. This <br /> excavation should proceed to a depth corresponding to the ground <br /> . water surface, which was approximately 16 feet in MW-1. At that <br /> time, we recommend that the excavation be backfilled. The <br /> excavation should proceed as soon as possible, so as to eliminate <br /> the potential hazards associated with an open excavation. We <br /> feel that remedial actions required to address ground water <br /> contamination can proceed effectively after the excavation has <br /> been closed. These measures will probably include drilling of <br /> additional wells in order to delineate the contaminant plume and <br /> to collect and treat the contaminated ground water. <br />