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The designs and specifications for each structure are presented in Exhibit 7, Hydrology <br />Information and Exhibit 17, Haulroad and Facilities Modifications. All ponds, impoundments <br />and diversions are designed to meet or exceed the requirements of 2.05.3(4) and 4.05.6. <br />The initial phases in construction of sedimentation pond embankments has been and will be <br />to clear all unstable material and to scarify the entire surface. In no instances was or will coal <br />processing waste be used as an embankment. All fill material was and will be selected to <br />exclude the presence of sod, large roots, and frozen material. The placing and spreading of <br />fill material was and will be started at the lowest point of the foundation. <br />All ponds, regardless of size, will be examined quarterly for structural weakness, erosion and <br />other hazardous conditions. Maintenance procedures may include mowing or cutting <br />excessive vegetative growth to facilitate inspections and repairs keeping ditches, culverts and <br />spillways free of debris, and removing all combustible material other than mulch and other <br />material required for erosion control and surface stability. Sediment will be removed from all <br />sedimentation ponds when the volume of sediment accumulates to 60% of the design <br />sediment storage volume or when sufficient volume is not available to treat. the predicted <br />runoff and sediment volume from a 10-year, 24-hour storm event.. The accumulated <br />sediment found in the ponds will be removed and placed in existing topsoil stockpiles if the <br />sediment meets the appropriate topsoil criteria, otherwise disposed of 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 to be constructed <br />within the permit area are shown on the Hydrology -North Map (Map 1 I) and the Hydrology <br />- South Map (Map 12j. These maps also show the locations of watershed boundaries from <br />which, along with other sources, the design criteria were established. Generally, ponds and <br />spillways were 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 event. <br />`I <br />2.05-22 Revision Date: 1/96 <br />Revision No.: MR-36 <br />