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Following topsoil removal, required drainage and sediment control structures will be constructed or installed. These structures include the upslope road drainage ditch, road crossings of smaller ephemeral drainage channels; discharge control structure (rock check dam) at the down-gradient limit of the shaft pad, and a temporary diversion ditch around the up-gradient perimeter of the shaft pad. The drainage from the shaft pad is addressed under a Small Area Exemption (SAE), as both the associated drainage area (4.3 acres) and the pad disturbance (2.5 acres, includes 0.2 acre ditch disturbance) are relatively small, the pad will be gravel-surfaced, and the remainder of the drainage area is undisturbed and vegetated. The access road follows variable topography, generally consisting of rolling terrain, and will be gravel-surfaced, so access road drainage control requirements aze minimal. Atypical road drainage ditch design is provided in Figure 2 of Exhibit 8T, prepared by Water & Earth Technologies, Inc, April 2004. Six (6) culverts are required to remove the flow from the runoff ditches to limit runoff velocities in the ditches to less than or equal to 3.75 feet per second (fps). This will assure that the ditches remain stable with no channel scour or degradation during peak flow events. Breaks in the topsoil windrow will allow runoff to drain. All drainage calculations and documentation are provided in Exhibit 8T, the SAE demonstration is provided later in this section, and the drainage structures are shown on Map 24. The SAE demonstration includes ditch sizing for the upland diversion ditch and road ditch. Construction of the ventilation shaft access road will involve topsoil recovery and windrowing, installation of required drainage structures, scarification and re-compaction of surface materials, and placement and compaction of approximately 8" of pit-run gravel and 3" of suitable road-base material. The access road surface will be approximately 24' wide and will be graded and crowned to promote effective drainage. Road construction requires minimal cut and limited fill, so the actual road disturbance area will average approximately 35' wide. Cut slopes will be established at a maximum of 1.5H:1V and fill slopes will be graded to 2H:1V or less, with all disturbed slopes to be stabilized by seeding with the topsoil stockpile stabilization seed mixture. For permitting purposes, a road disturbance corridor 100' wide has been defined as encompassing all project-related activities, including road construction and topsoil stockpiling/windrowing. Preparation of the ventilation shaft pad will involve topsoil recovery and stockpiling, installation of required drainage structures, grading and compaction to establish a level pad working area, excavation of a collection pit for blind drilling of the shaft pilot hole and shafr, haulage or stockpiling of the excavated bottow material, and placement of gravel surfacing material to control dust and sediment from the pad area. Excavated borrow material from the collection pit will be hauled to the nearby Fish Creek Loadout for use in final reclamation. The collection pit will be approximately 100' x 200' x 10' deep and is sized to contain all drilling fluids and cuttings. In the event unanticipated ground water flows are encountered, they would occur during drilling of the pilot hole when the collection pit would have significant excess capaciTy. The combination of excess capaciTy and flow controls should be adequate to prevent any off-site discharge. FaciliTy construction details and configuration are illustrated by Maps I S-50 and 1 W-50 in Exhibits 16C and 16D. The cuttings pit and associated foundation area will be inspected during topsoil stripping, placement of the liner, and temporary closure, on completion of shaft boring operations. As-built certification will be provided to the CDMG prior to cuttings placement and following temporary closure. Primary Method of Construction -Blind Drilling Prior to the beginning of the blind drilling process, a pressurized pre-grout operation utilizing up to ten small diameter (2") holes, up to approximately 400' deep around the shaft perimeter will be considered and undertaken, as needed, to limit groundwater flows between the shaft and the formations. Individual grout holes would be drilled and a cement grout would be pumped under pressure into each borehole before completing the next hole, to seal any wet zones encountered. Each borehole would be filled with grout and allowed to set-up, effectively sealing the borehole and any fractures or voids in the grouted formation(s). Any surface casing extending above ground surface will be cut-off flush with or below natural ground level. If needed and once the pre-grout operation is completed, a shaft collar will be excavated to an approximate 10' diameter to competent rock at a depth of approximately 10-15 feet. Material from the collar excavation will be placed within and on one end of the cuttings pit. A surface casing approximately 8' in diameter (inside) and large enough to accept the shaft casing and drilling tools will be installed in the shaft collar. This surface casing will be either steel casing grouted in-place or cast-in-place concrete. MROS-192 2.05-45.4 03/22/05