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• d. Appropriate combinations of principal and emergency spillways to safely discharge the runoff from a 25-year, 24-hour precipitation or larger event, as required by the CDMG's regulations, will be installed. The sediment storage capacity of the sedimentation pond will be periodically monitored to ensure that at least one year of sediment storage is available beneath the principal spillway inlet (based on the U.S.L.E. or the equivalent sediment storage of one 10-year, 24-hour storm event based on the M.U.S.L.E.). When adequate capacity is no longer available, sediment removal or other corrective actions will be taken to restore adequate sediment storage capacity to the pond. Corrective action required to restore adequate sediment storage capacity may include the following: 1. Raise the spillway and redesign the pond in order to restore adequate storage capacity and to comply with the applicable regulations. 2. Excavate the pond area and enlarge the sediment storage capacity. The excavated material suitable for topsoil will be salvaged in a stockpile used for reclamation. The excavated material that is not suitable for atopsoil-like medium will be graded into the surrounding topographywithinthedisturbancearea,topsoiled,andrevegetatedinaccordancewithWFC'sapproved reclamation plan. Site specific conditions will determine the construction methods and equipment utilized at the time of excavation. Sediment removal and water discharges will be conducted consistent with the approved mining permit, the NPDES permit, and CDMG Regulations Section 4.05.6(3)(b). All sedimentation ponds will be inspected quarterly under the supervision of a registered professional engineer and reported to the CDMG. Pit dewatering will be primarily a seasonal occurrence. The dewatering process will be a sporadic, operation-controlled occurrence depending on various factors which may include the location of the pit inflows, the location ofstanding waterin the pit, or the location within the pitofthe overburden and coal removal operations. When pit dewatering is required, the anticipated dewatering rate will be in the range of one to two cubic feet per second or less. Most dewatering discharges will be directed to 007 East and West Ditches, which drains into Pond 007. However, direct pit pumping into Pond 007 may occur if conditions warrant. These procedures have been approved in WFC's NPDES Permit CO- 0000213. Actual water flow velocity going into Pond 007 will be controlled with adequate energy 2.05.3(3) - 6