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The material excavated will 6e tested to determine its suitability as topsoil and utilized in reclamation. <br />The material that is not suitable for topsoil will be graded into the surrounding topography within the <br />S. disturbance area, topsoiled, and revegetated in accordance with the approved reclamation plan. <br />Site specific conditions will determine the construction methods and equipment utilized at the time of <br />excavation. Sediment removal and water discharges will be conducted consistent with the approved <br />mining permit, the NPDES permit, and Section 4.05.fi(311b1. All sedimentation ponds will be inspected <br />quarterly under the supervision of a registered professional engineer and reported to the DMG. <br />Based on SCC's previous experience et the Seneca II-W Mine, pit dewatering will be primarily a <br />seasonal occurrence. The dewatering process will be a sporadic operation-controlled, occurrence <br />depending on various factors which may include the location of the pit inflows, the location of standing <br />water in the pit, or the location within the pit of the overburden and coal removal operations. When pit <br />dewatering is required, the anticipated dewatering rate will be in the range of one to two cubic feet per <br />second or less. Any dewatering discharges will be directed to a pond. The discharge from the pit <br />dewatering will be controlled, as necessary, with an adequate energy dissipator (i.e., rock riprap, <br />geotextiles, metal or concrete energy dissipator boxes, etc.) or discharged onto non-erodible bedrock <br />material. Pit dewatering will have an insignificant impact on the proposed ponds. The pit dewatering <br />will be sporadic versus continuous. The flow rate of one to two cubic feet per second or less <br />compared to the design 10-year, 24-hour peak inflow rate is very insignificant. In addition, all <br />discharge from ponds will be in accordance with applicable discharge permits. <br />• <br />All sedimentation ponds and impoundments will be maintained until the disturbed areas are reclaimed <br />and the vegetation success requirements of Tab 22 are met, the untreated drainage from the disturbed <br />area ceases to contribute additional suspended solids above natural conditions, and the drainage leaving <br />the pond meets applicable State and Federal water quality requirements, if any, for the receiving <br />streams. All temporary ponds will be removed when the appropriate sections of the regulations are <br />satisfied. Permanent impoundments will be reevaluated prior to bond release and remedial construction <br />performed to satisfy the appropriate sections of the regulations. <br />When sedimentation ponds are removed, the affected land will be regraded and revegetated pursuant to <br />the DMG's regulations, Section 4.05.17 and the approved Reclamation Plan. <br />Design Methodology. The precipitation runoff (peak flow and volume) is estimated using the Soil <br />Conservation Service (SCSI triangular hydrograph techniques as described in Design of Small Dams <br />IU.S. Dept. of Interior, 19771. Computations necessary for this runoff estimating technique have <br />been computerized by various individuals and agencies. SEDIMOT II was developed by Research <br />Specialist Bruce N. Wilson, Professor Billy J. Barfield, and Assistant Professor Ian D. Moore at the <br />Department of Agricultural Engineering, University of Kentucky, Lexington, Kentucky. SEDCAD+ is en <br />enhanced PC version of the SEDIMOT II computer program (see Attachment 13-11. This program is <br />• used to estimate runoff peak flow and volume which are necessary for the design of sediment ponds, <br />5 Revised 9/98 <br />