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Mr. Dean Willis Page Two October 18, 1990 The slot was created by excavating radially in each location to create a slot that extended to the top of the slope of the excavation wall. A sample of soil was collected from a backhoe bucket approximately 17 feet below the grade and immediately below the top of the slope in each slot. The slot was deepened by excavating to a depth of approximately 32 to 35 feet below grade. Another sample was collected from each slot at 32 to 35 feet below grade under the top of slope of existing pit. After all the samples were collected from a given slot, the slot was backfilled with the soil which was removed from that slot. Field Observations The depth of the existing floor of the excavation was estimated prior to proceeding with the excavation. The existing floor was at an elevation of approximately 15 feet below grade. The native soil at that elevation was a clay material. A sandy material was encountered between 20' to 25' below grade. The sandy material was present to the base of each excavated slot (approximately 32' to 35' below grade). Some additional clay was found at a 35' depth. Since the excavation was halted at 32' to 35' below grade, the extent of the lower clay layer is unknown. Sample S2A-2' was the only sample in the upper clay layer that exhibited obvious hydrocarbon contamination. The soils continued to appear to be clean to a depth of at least 25' below grade. Below 25' a layer of stained soils were found which exhibited a hydrocarbon odor. This layer of stained soil extended to the base of each excavated slot. The slots were not extended into groundwater. A sampling record is given in Table 1. Analytical Results Thirteen samples were analyzed for Total Petroleum Hydrocarbons (gas and diesel) and Benzene, Toluene, Xylene, and Ethylbenzene (BTX&E). The analytical results are given in Table 2. Three samples were held. for possible later analysis. The analytical results indicate the presence of diesel in all samples except S5B-17'. Most of the samples had TPH Diesel concentrations in the 2 to 10 ppm range. Gasoline and the aromatic hydrocarbons were absent from all samples except S2A-2' and S6B-18'.