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r iJJ11 Huddleston -Berry r.:r s T z, t.t c 4.2 Geologic Constraints C The primary geologic constraint to construction at the site is the presence of steep slopes on the north side of Highway 141. It will be critical that mining operations be conducted carefully in accordance with the mining plan as to not impact the slopes above Highway 141. Slope stability will be discussed further in a later section of this report. 4.3 Water Resources No water supply wells were observed on the property. As discussed previously, shallow groundwater was not observed at the time of the investigation. In general, with proper design and construction of the detention basins, the proposed mining operations are not anticipated to adversely impact groundwater or surface water. 5.0 SLOPE STABILITY As discussed previously, steep slopes were observed on the south side of the site along Highway 141. In order to evaluate the impacts of the proposed mining on the slopes HBET conducted limit equilibrium slope stability analyses using the GSTABL 7 computer software package. In addition, HBET conducted analyses on the proposed finished interior pit slopes and proposed detention pond embankment dams. The results of the analyses are included in Appendix B. 5.1 Highway 141 The slope stability analyses for the slopes along Highway 141 were conducted on the critical section consisting of the highest and steepest cut slope. The analyses included the Highway 141 roadway and extended down to West Creek. As discussed previously, the regional groundwater conditions are unknown; however, for the analyses, the groundwater elevation was modeled as the approximate elevation of West Creek. In general, considering that the existing cut slopes are stable, groundwater is not anticipated to have a significant impact on the proposed conditions. With regard to soil shear strength parameters, HBET believes that the selected parameters are conservative as the critical existing cut slope is stable at an angle of approximately 42 °. As shown in the results of the analyses included in Appendix B, there is no change in the minimum factor-of-safety against global stability from the existing and Y g post- mining cases. Therefore, as long as the mining operations provide some protection l� against raveling of material during the early stages of mining and provided the mining is conducted in accordance with the mining plan, HBET does not believe that the mining of materials in the western portion of the site will adversely impact the stability of existing L slopes along Highway 141. W:\2009 ALL PROJECTS \00966 -Moores Mining, LLC \00966 -0001 Moores Pit\200 - Geo100966 -0001 R030310.doc