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• Notes: Maximum cuts or fills designated with an asterisk exceed regulatory standards and require CDMG approval of altemative specifications based on a geotechnical demonstration of stability Average surface width is for the travel-way. Total road surface area includes required safety berms and drainage ditches. Road disturbance area includes road surface area and any required cuts and fills. Unless specifically indicated, altemative specifications are not necessary since road designs comply with applicable regulatory standards. In those areas where altemative specifications are necessary due to cut or fill requirements, geotechnical stability analyses have been completed for the design configuration to demonstrate stability consistent with Rules 4.03.1(3)(a), (d), and (e) and 4.03.3(a), as discussed under the heading, "Road Stability Analyses". Road design and stability analyses for steep-slope areas reflect benching or keying of the slope and controlled fill placement and compaction, consistent with applicable provisions of Rule 4.03.1(3)(e). Roads are designed and constructed with a safety berm approximately 2 to 3 feet high on the outer (downslope) edge of the travel-way and a road drainage ditch on the upslope edge of the road. Road ditches are designed to safely carry the flows from the 10-year, 24-hour storm event with a minimum freeboard of 0.3 foot. Ditch sideslopes will be cut at approximately 2H:1V or 5H:1V. Cross-drains and designed culverts are located and • designed to route road drainage to the existing natural ephemeral drainages. Road drainage culverts and any culvert crossings of ephemera] streams are sized to safely pass the flows from the 10-year, 24-hour storm event. Road drainage ditch and culvert requirements in conjunction with road construction are addressed in Exhibit 2.05-E3, Drainage and Sediment Control Plan. Required road drainage features are shown on the Drainage and Sediment Control Plan Map, (Map 2.05-M4 (Sheet 5 of 5)). ROAD STABILITY ANALYSES A road stability analysis was completed for the II West Haul Road using SLOPE/W computer software that uses a search routine to determine the most critical failure surface(s). A worst-case road cross-section, as shown on the Facilities Details - II West Coal Refuse Facility (Map 2.05-M3 (Sheet 3 of 3)), with 1H:1V cuts and 1.SH:1V fills was analyzed for stability. The proposed road alignment is located relatively high on the south-facing slope and is well above the relatively deep alluvial/colluvial deposits characteristic of the lower slope and valley areas. Where developed soils exist and are operationally feasible to salvage, they will be removed, so road construction will occur in the inter-bedded sandstones, shales, siltstones, and mudstones of the Bowie Formation. Given the relatively steep natural slopes, the stability analysis assumes that any fills will be benched into the Bowie Formation, consistent with Rule 4.03.1(3)(e)(ii), and will not be placed directly on alluvial or colluvial materials. • The following summarizes material types and associated shear strengths used in the stability analysis: TR-43 3 September 2003