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I C Project No. E6576.001 itional Groundwater Sampling/W. Clover flw� 22 March 1995 � f backfill sands were removed, and these were found to locally extend to a maximum depth of 10.0 feet. Contaminated areas of the native soils in the original tank pit walls and bottom were also removed. These could be discerned on the basis of odor and/or stain, the native tan to Clight red-brown color being locally discolored to various shades of grey. The water level in the excavation was measured at a depth of 6.5 feet. Although there was some difficulty in r removing contaminated soil below the water table, much of the original excavation work was L done with a minimum of groundwater; and most of the loose muck was clean cave-in from the sidewalls of the pit. C Approximately 300 cubic yards of material was removed, of which about 100 cub yards were clean overburden. The clean soils were segregated from the soils observed to be contaminated. On Monday, November 7, after the bulk of the excavation had been completed, a grab sample was taken from the water that was standing in the pit. No contamination was ll found (see Table 2, below). During the excavation, it was observed that the only 11 '1 contamination odor was that of diesel; and, since the records indicated that the tanks held diesel L fuel, it was agreed that subsequent testing would be for diesel and BTEX rather than motor oil and BTEX. The locations of the confirmatory soil samples in the excavation pit and ..J overburden stockpile are given in Figures 2 and 3, Appendix A. Samples were taken from eight locations in the contaminated soils stockpile, at depths of 1.5 to 2.0 feet. These locations are given in Figure 4, Appendix A. EXCAVATION SAMPLING RESULTS The results of the confirmatory samples test results are given in Table 3 below. The results of the "contaminated" stockpile sampling are given in Table 4. It is seen that, even in the "contaminated" stockpile, contamination is very low. The eight samples were composited into two 4 to 1 samples, one of which was found uncontaminated and, in the other, the only Ccontamination was 22 ppm of diesel. C TERRASEA RCH, INC. Page 7