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3.0 SIIE GEOLOGIC AND HYDROGEOLOGIC CONDITIONS A limited assessment of site geologic and hydrogeologic conditions was obtained through the soil borings and monitoring wells discussed above (Figure 2), as well as those located in Parcels I and II. Geologic and hydrogeologic conditions are discussed for the overall site. Conditions unique to Parcel III, are identified as such. 3.1 GEOLOGY Parcel ifi geologic conditions are depicted in two schematic geologic cross sections as located on Figure 3. Soil boring and monitoring well lithologic logs are presented in Appendix D. Cross section A-A' (Figure 4), oriented north to south begins at B-4 near the loading dock and extends along the conveyor easement to MW-1 in the northeastern portion of Parcel III, and then through Parcel III ending in the southeast corner at MW-4. Cross section B-B' (Figure 5), oriented west to east begins at B-7 in the southwest corner of Parcel III, extends across the southern boundary of Parcel III, through the northern portion of Parcel II, and ends at MW-4 in the southeast corner of Parcel III. The surface materials along the conveyor easement are comprised of dry light brown very fine grained silts and silty sands mixed with residual coal and petroleum coke. The maximum measured thickness of this residual material was 0.75 feet at boring B-5 (Figure 4). Underlying the residual materials along the easement is a thick organic rich fill. The fill material is comprised of moist coal-like organic material, black sandy asphaltic-like gravel, and pea gravel mixed with silt and clay fines. The maximum measured thickness of this organic rich material is 4.25 feet at boring B4. This organic rich fill material was encountered in borings B-4, B-5, and B-6 and appears limited to the area north of Parcel III which includes the conveyor easement (Figure 3). This material was not encountered south of the train tracks, in the main body of Parcel III (Figure 4). Residual petroleum coke, coal, and copper concentrate materials cover the surface in portions of the site formerly used for commodities stockpiling. These areas are referred to as fill on cross section B - B'(Figure 5). The residual material (fill) appears primarily in the southwest portion of Parcel III, and the northern portion of Parcel II. This material was encountered in borings B-7, B-3, and B-2 (Figure 5). In all three borings, the fill was found to be no more than three inches thick. The native materials underlying the fill are predominantly very fine grained sediments. For ease of discussion, the materials are grouped into three zones, based primarily on grain size. The first zone encountered is comprised primarily of very fine grained silts, sandy silts, silty sands, and silty clayey December 20, 1991 SAC28.013 5