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Revised January, 1996 <br />The designs and specifications for each structure are presented in Exhibit <br />• 7, Hydrology Information and Exhibit 17, Haulroad and Facilities <br />Modifications. All ponds, impoundments and diversions are designed to meet <br />or exceed the requirements of 2.05.3(4) and 4.05.6. <br />The initial phases in construction of sedimentation pond embankments has <br />been and will be to clear all unstable material and to scarify the entire <br />surface. In no instances was or will coal processing waste be used as an <br />embankment. All till material was and will be selected to exclude the <br />presence of sod, large roots, and frozen material. The placing and <br />spreading of fill material was and will be started at the lowest point of <br />the foundation. <br />All ponds, regardless of size, will be examined quarterly for structural <br />weakness, erosion and other hazardous conditions. Maintenance procedures <br />may include mowing or cutting excessive vegetative growth to facilitate <br />inspections and repairs keeping ditches, culverts and spillways free of <br />debris, and removing all combustible material other than mulch and other <br />material required for erosion control and surface stability. Sediment will <br />be removed from all sedimentation ponds when the volume of sediment <br />• accumulates to 60~ of the design sediment storage volume or when sufficient <br />volume is not available to treat the predicted runoff and sediment volume <br />from a 10-year, 24-hour storm event. The accumulated sediment found in the <br />ponds will be removed and placed in existing topsoil stockpiles if the <br />sediment meets the appro- priate topsoil criteria, otherwise disposed of <br />in the pit backfill. <br />Sedimentation pond removal is discussed in Section 4.05. <br />The location of all proposed sedimentation ponds and diversion structures <br />to be constructed within the permit area are shown on the Hydrology - North <br />Map (Map 11) and the Hydrology - South Map (Map 12). These maps also show <br />the locations of watershed boundaries from which, along with other sources, <br />the design criteria were established. Generally, ponds and spillways were <br />sized and placed according to such hydrologic factors as required sediment <br />storage volume, rate of flow and volume of flow for the appropriate storm <br />event. <br /> <br />2.05-22 <br /> <br />