2007-06-29_PERMIT FILE - C1981022A (2)

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Section - 2.05.3 The first segment of the Elk Creek haul road will extend from the point where the ~Xtest Valley haul • road connects to the Elk Creek road approximately 400 feet to the toe of the lower Elk Creek Mine portal bench. This segment of the road will provide full access to the Elk Creek Mine for haulage of coal, coal refuse, mine development waste, men, equipment, and supplies. This section of the road will be construtted as a cut-fill road along the alignment of the existing road with an average grade of approximately 11 percent. The second segment of the Elk Creek haul road flattens slightly beginning from the north end of the first road segment and extending approximately 300 feet to another steeper road segmen[. Similaz to the first road segment, this ramp is designed to provide full access to the lower portal bench. The access ramp will be constructed almost exclusively on fill at a grade of approximately 9 percent. The third segment of the Elk Creek haul road includes an initial shott (200 foot), relatively steep segment and then flattens along the top of the Elk Creek Mine ponal bench. This segment will begin at the top of segment 2 and run approximately 545 feet, ending in the open yazd area around the Elk Creek Mine portals. The third road segment will be constructed exclusively on the portal fill bench with an average grade of approximately 8 percent. Drainage control for the Elk Creek haul road will consist of roadside ditches, uoss-culverts, alternative sediment control structures, and runoff collection ditches that will intercept and route a portion of the drainage to Sedimentation Pond D. Drainage control for the upper portion of the road (second and third segments) will be provided by the drainage and sediment control structures for the Elk Creek Mine portal bench including collection ditches, berms, and alternative sediment control structures. Roadside ditches, culverts, and alternative sediment conuols will provide drainage conaol far the lower portions of the road (ftrst segment). A culvert crossing will be constructed under the third segment of the road, with a 9-foot diameter steel culvert providing sufficient capacity to safely • pass the flows from the 700-year, 24-hour storm event with a significant margin of excess flow capacity. Drainage design details aze provided in Exhibit 2.05-E3, Drainage and Sediment Control Plan. II West Haul Road -Development of the II West Coal Refuse Facility in 2003 to replace the West Valley Coal Refuse Facility, as the active coal refuse disposal area, required construction of a new haul road for access and coal haulage The II West Hau] Road begins at the switchback on the existing West Valley Haul Road and consists of three road segments. For all road segments, road width and grade are appropriate for the volume of traffic and weight and speed of vehicles that use the road. All road segments will be used for access for initial construction of the coal refuse facility, haulage of coal refuse, and access for maintenance and reclamation of the coal refuse facility. The road is grave]- surfaced and approximately 30 feet wide (travel-way), providing for two-way traffic over the entire road. Maximum speed limit for this road is 15 miles per hour. The natural terrain in the area where the road is constructed is relatively steep, so in many cases, compliance with standard cut/fill specifications would result in excessive cuts and fills and significant additional surface disturbance. Cut slopes are no steeper than 1.OH:1 V (except in rock where cuts may go up to 0.3H:1 V) and fill slopes are 1.5H:1V or less. The stability demonstrations for oversteepened slopes required under Rules 4.03.1(3)(d), and 4,03.1(3)(e) are provided in Exhibit 2.05-E4, Mine Development Rock/Coal Refuse Facility Design. The II West Haul Road layout was developed by OMI.LC, and haul road designs and stability analyses for any portions of the road {i.e., cuts/fills) which varied from the applicable Rule 4.03 Performance Standards were developed by MWH. Road stability analyses are provided in Exhibit 2.05-E4, Mine Development Rock/Coal Refuse Facility Design. Road plan and profile configuration is shown by • the General Facilities Map (Map 2.05-M1, Sheet 5), a Facilities Detail Map (Map 2.05-M3 series), and by the design drawings included in Exhibit 2.05-E4. TR-43 2.05-29 Revised August 2003