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• The material excavated will be 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 />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 4.05.61311b1~ All sedimentation ponds and <br />impoundments will be inspected quarterly under the supervision of a registered professional engineer <br />and reported to the DMG. A professional engineer will certify each sedimentation pond and <br />impoundment annually. <br />Based on SCC's previous experience at 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 Tess. 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 />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. Prior to submittal of a bond release <br />request, SCC will submit a complete technical revision demonstrating that each permanent <br />impoundment meets the requirements of 4.05.9(131 for permanent impoundments, <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 pesign of Small Dams <br />IU..S. Dept. of Interior, 19771. Computations necessary }or this runoff estimating technique have <br />TR-50 5 Revised 11 /04 <br />