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4.1.4 Sediment Pond Access Road <br />A sediment pond access road will be constructed prior to sediment pond construction and <br />• located and topographicaly bebw the cemetery/haul road, beginning at EI. 6,080 h. The haul <br />road will be constnxted ar an average grade of 1 percent before descending into the sediment <br />pond. The plan and profile of this road is shown on Drawing 95255-05 and details on <br />Drawing 95255.03. The road will be approximately 20 feet wide, with a small safety berm <br />on the outside. Runoff intercepted by this sedirrtertt pond access road will be minimal, so only <br />small, unlined ditch should be placed on the inside of the road. Small quantities of runatt and <br />associated sediment that may accumulate cannot bs routed to the sediment pond due to <br />topographic restrictions. A small area exemption from the sediment control requirements is <br />needed from the Division of Minerals and Geology, and best management practices IBMP1 <br />should be used, such as silt fences and revegetation. Proper maintenance should be <br />pertonned regulaAy to remove any collected sediment. The sediment pond access road should <br />be surfaced. maintained and reclaimed similarly to the haul road. <br />4.1.5 Runoff Corwd Ditches <br />Runoff comrol ditches wllf be bcated around the coal mine waste bank to divert runoff within <br />.~ <br />,~ and above the disturbed area produced by a 100-year, 24-hour stom- to the sediment pond <br />with a minimum of 0.3 feet of dry freeboard. This stone frequency corresponds to 2.8 inches <br />IJ.E. Stover & Associates, 1995). This storm was modeled as described in Section 4.2. <br />~Norksheets used in calculating fbw depths and velocities are attached in Appendix C. Riprap <br />and fitter material placed in these ditches for erosion protection were designed using <br />information in the Surtacs Mining Water Diversion Design Manwl by tM Office of Surtacs <br />Mining IOSM, 19821. In most cases, the ditch will have to be over-excavated to <br />accommodate the riprap and faker thickness requirements to achieve the proper channel <br />geometry. <br />Locations of the runoff convol ditches are shown on Drawing 95255-01. Side dhches <br />primarily run abng the contact between the coal mine waste bank and the natural ground. <br />These ditches shook) be a minimum of 1-foot deep, wish 2:1 aids sbpss, and will require sbps <br />protection in the form of riprap. Riprap with a protective faker layer bebw shook) follow <br />requirements shown on Drawing 95255-03 for the side dRchss. The 23-inch maximum riprap <br />size recommended for these side ditches is large, compared to ditch size and flow depth. This <br />~"'~ <br />• <br />96266/1424.RPT Cwl M'rr W~K~ 9~nk [?wipe far tM Sanborn GNk Mir <br />OetoWr r99e WESTEC, Ina. 1tl <br />