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~. C. Phase III Phase III initiates full development of the South Quarry and focuses on the upper (western) portions of the South Quarry area. At the end of Phase [II, the westem half of the South Quarry will be developed into highwalls and benches, with the eastern half consisting of a flat platform at approximately EI.6,640 ft. The proposed new Phase III configuration is shown in Figure D-3, Exhibit D -Phase I[I Mining Plan Map. Mining will generally occur on two "fronts" simultaneously: one begins high to the west and progresses down slope, and the second extends the existing Central Quarry to the south. For improved visual appearance, there will be 40 ft highwalls and 60 ft wide benches for the upper approximately 650 ft of the westem side of the South Quarry. This configuration will allow for reclamation fills to extend higher on highwalls than a steeper highwall and bench slope configuration and CAMAS intends to completely backfill these benches as has already been done (to steeper configurations) in the Central Quarry. Additionally, higher benches will be reclaimed amcurtently as mining proceeds on lower benches to reduce the duration of visual exposure. D. Phase [V Phase P/ finalizes development of the South Quarry and the entire Morrison Quarry by lowering the bottom of the South Quarry to El. 5,840 ft. This development is below the remaining ridge to the east and will not be generally visible to viewers from below and to the east. Therefore, it will be developed in more aggressive configuration of 40 to 80 ft highwalls and 40 ft benches depending on the rock mass and stability considerations. The proposed new Phase IV configuration shown in Figure D-4, Exhibit D -Phase IV (Final) Mining Plan Map shows the maximum possible buildout, ongoing geotechnical analyses notwithstanding. The quarry will be developed to the maximize recovered volume within the footprint of the limits of mining depending on local geotechnical considerations. Mining will occur within the limits of mining. Additional access, stockpile, and reclamation activities will occur in the areas between [he limits of mining and [he limits of disturbance. The maximum recoverable volume is dependent on [he final cut slope angles within the mine which in tum are dependent on the strength and other geotechnical properties of the rock mass. The mining plans shown in Figures D-1 through D-4 show [he maximum possible buildout configurations which are likely to be achieved assuming rock mass properties are sufficient to support the steeper walls shown at depths not yet exposed. These anticipated maximum buildout conditions are based on [he current database of geotechnical properties and slope stability modeling evaluations performed to date. Ongoing observations and evaluations will be used to refine slope configurations as various portions of the quarry are developed. Based on presently available information, it is not practical to model the rock mass in sufficient detail to predetermine absolute final slope configurations. Consistent with Amendments Nos. 3 and 4, the G:VROIECfSV'0300~OOTTEXTUAtENDOS.T%T IV - 3