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Mr. Dan T. Mathews Page Three July 8, 1982 V. Operational Considerations Bear Coal Company will comply with the requirements of Section 4.05.2(2). Adequate storage µolume exists in the sediment control structure to store sediment from runoff fora year. Bear Coal Company will inspect and clean the sediment from the pond annually if l necessary to ensure that adequate storage volume is maintained. J An open orifice dewatering device/principal spillway will be included and located in the sedimentation pond to avoid I discharging water through the emergency spillway as the result of a 10-year, 24-hour precipitation event. As shown on the Drainage and Sediment Control Plan Flap (I.1ap S-1), much of the portal bench and associated road will be graveled. Drainage from the bench will flow through Ditch "A". The slopes above the portal area will be seeded and stabilized as set forth in Section 2.05.4 in Bear No. 3 application. The conveyor system utilized to transport coal from the portal area to the crushing and loading area will be routinely inspected and maintained. Spillage of coal will be minimized by careful operating procedures to minimize contributions of coal to the ' surface runoff which may occur front snowmelt and/or rainfall. The high flow velocities through Ditches "A" and "B" result from the grade at which the ditches must be constructed. The steep ' terrain requires that these ditches must be adjacent to the access road. Because of the high velocities of flow, each ditch will be lined with rip-rap material +6 inch in size as shown ' within Exhibit 11 of the Mining and Reclamation Plan. Corresponding changes in the design of each ditch has been made to incorporate a minimum of freeboard of 0.30 feet as shown on ' the attached Figure 4. Stipulation No. 2 The Colorado Highway Department has designed and will reconstruct the river channel of the North Fork of the Gunnison River near the Bear No. 3 Mine in Somerset to contain a 100-year flood event. ' Stipulation No. 3 ' As discussed in Section 2.04.7 of the Bear No. 3 application, groundwater is not expected in the underground workings. However, to comply with the request of the Division, a sump will be constructed in the undergrounding workings to handle any water. 1 A ~ ~ tNC.