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operations which gets into these areas is collected in sumps and pumped to the process water <br />settling pond. This water is then used in the makeup water cycle. Special attention is given to water <br />containing significant amounts of coal fines as the water might have characteristics more objection- <br />able and more difficult to treat than would runoff from other disturbed areas. <br />Sediment control systems along the conveyor consist of ditches and berms to return runoff to a <br />natural drainage area. Culverts are also used for controlling drainage. Two ponds are used at the <br />slot storage area (SS-1 and SS-2). Ditches, berms, and culverts direct runoff from the top of the slot <br />area into SS-1. Diversion ditches direct runoff from a disturbed laydown area on the west side of <br />the slot storage area to SS-2. <br />The sedimentation and drainage control system used in the Refuse Disposal Area are slightly <br />different as shown on Maps 76, 77, 77A, 78, 79, 80 and 80A. The watershed of a sub-area is <br />progressively disturbed as the sub-area is filled with refuse. During this process, runoff from <br />undisturbed areas is diverted away from disturbed areas by temporary ditches. The purpose of <br />these temporary ditches is to prevent excessive erosion of the refuse and not to prevent mixing of <br />runoff from disturbed areas. The perimeter diversion ditches into the sedimentation ponds carry <br />both runoffs. Both types of runoff are mixed. This is not considered detrimental as the watersheds <br />are small and the ponds are designed for the worst expected situations (i.e., when most of the <br />watershed is disturbed). Sediment design and diversion ditch calculations are given in Illustrations <br />• I-4 for refuse area 1 and I-6A for refuse area SA. With the approval of TR42 to combine refuse area <br />RP-2/3 and RP-4 into RP2/3/4, the sedimentation design and ditch calculations are given in <br />Illustration 44. In order to maintain a 10-year runoff storage volume after a major storm event, the <br />water level in Pond RP-2/3 will be dewatered 1.6 feet, the water level in Pond RP-4 will be <br />dewatered 2.0 feet and the water in Pond RP-5 will be dewatered 1.65 feet below the primary <br />spillway. <br />The DP-1 Pond decant hole will be controlled by a valve. Since DP-1 discharges frequently, the <br />valve will normally be kept open. The valve will be closed if a need arises to provide more settling <br />time for solids in the water. See Map 80B. <br />In accordance with Rule 4.05.2(4) runoff from the haul and access roads will not pass through <br />sedimentation ponds unless within the portal or refuse disposal areas. Check dams to slow the <br />velocity of water collected in ditches alongside the roads were installed during the construction <br />phase. All ditches have been revegetated and check dams inside ditches are no longer used. <br />Water relief bars divert water out of the ditches into natural drainages at appropriate points. <br />• Permit Rev. 4 (11/2002) IV-39 <br />