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• Haul roads will be reclaimed after their use for mining operations. All culverts will be <br />removed, and natural drainage patterns will be restored. Cut and fill locations will be <br />recontoured to match the surrounding topography. The road bed will be ripped and scarified, <br />as necessary, before the recontoured cut and fill slopes are revegetated. Terraces or other <br />means will be constructed to prevent excessive erosion. <br />The haul road for the cover fill stockpile will be constructed similarly to the waste bank haul <br />road. No cuts will be required for construction, and the road will be removed as the stockpile <br />is depleted. <br />4.1.4 Runoff Control Ditches <br />Runoff control ditches will be located around the coal mine waste bank to divert runoff within <br />and above the disturbed area produced by a 100-year, 24-hour storm to the sediment pond <br />plus a minimum of 0.3 feet of dry freeboard. This storm frequency corresponds to 2.6 inches <br />(J. E. Stover & Associates, 1995). This storm was modeled as described in Section 4.2, <br />Worksheets used in calculating flow depths and velocities are attached in Appendix C. Rpprap <br />and filter material placed in these ditches for erosion protection were designed using <br />• information in the Surface Mining Water Diversion Design Manual by the Office of Surface <br />Mining (OSM, 1982). In most cases, the ditch will have to be over-excavated to <br />accommodate the riprap and filter thickness requirements to achieve the proper channel <br />geometry. <br />Locations of the runoff control ditches are shown on Drawing 95266-02. Side ditches <br />primarily run along the contact between the coal waste bank and the natural ground. These <br />ditches should be a minimum of 1.5-feet deep, with 2:1 side slopes, and will require slope <br />protection in the form of riprap. Riprap with a protective filter layer below should follow <br />requirements shown on Drawing 95266-04 for the side ditches. The 35-inch maximum riprap <br />size recommended for these side ditches is large, compared to ditch size and flow depth. This <br />requirement provides for the stability of the material under loads transferred by flowing water <br />and for mass stability of the riprap itself. If, at the time of construction, it is found that <br />placing riprap this size is not practical, as a contingency it is suggested that the D60 material <br />size, 24-inches, be placed and secured using grout. If grout is used to secure riprap, proper <br />design, compacted subgrade, and periodic maintenance is required. Bowie Resources will <br />• <br />96266/1424.RPT Coel Mine Waste Bank Finel Design for the Bowie No. 2 Mina <br />June 7996 W E S T E C 10 <br />ADEQUACY-Ol <br />