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• Section 2.05.6 and aze designed to manage the ten and twenty-five year <br />precipitation events as required by regulation and in accordance with the <br />requirements of National King Coal's N.P.D.E.S permit No. CO-G-850001. <br />PONDS, IMPOUNDMENTS, AND DIVERSIONS <br />DRAINAGE PLAN <br />The drainage plan for the King II Mine will consist of diversion of <br />uncontaminated water originating upstream of the mine yard, through <br />the yard to the dischazge point at the south end of site. Runoff <br />generated on the yard itself will be collected and routed through the <br />sedimentation ponds. <br />Refer to 2.05.6 (Hydrologic Balance) and Appendix 10 & 11 for a detailed <br />description of Mine Surface Drainage and Sediment Pond design and <br />descriptions. <br />The sediment control system for the King II Mine will be comprised of <br />undisturbed azea drainage ditches and one sediment pond. Designs for <br />sediment control system structures are included in Appendix 11. <br />Approximately 1.3 acres of the disturbed azea lies below the <br />• sediment pond, consisting of the haul road between County Road 120 <br />and the north end of the Sediment Pond. Runoff from this area will tend <br />to collect and drain along the haul road bypassing the sediment pond. <br />Alternate sediment control measures are to be used in this area. These <br />measures consist of the use of rock check dams, rock filters and gravel <br />surface. This area is too small and too flat to run a SEDCAD <br />demonstration. Therefore, National King Coal, LLC commits to sampling <br />any discharge from this area for Total Settable Solids. This runoff flows <br />into the area on either side of the haul road. This azea will be similaz to <br />Small Area Exemption # 1 of the current King Coal Mine permit, as <br />approved by the Division. <br />AREA DRAINAGE DITCHES <br />Two undisturbed area drainage ditches will convey undisturbed surface <br />flow azound the disturbed area of the mine surface facilities and return <br />the flow to the native surface drainage channel below the mine bench. <br />The ditches encircle the mine disturbance. One ditch conveys surface <br />flow along the west side of the mine facilities to the native channel, while <br />the corresponding ditch drains east and south above the mine portal and <br />down the east side of the mine bench and surface facilities to the native <br />channel. These open earthen channels will be sized to contain the 25 <br />yeaz-24 hour precipitation event. The channels will be stabilized with a <br />• combination of vegetation and riprap (where necessary). <br />National King Coal, LLC King II Mine <br />Section 2.05.3 <br />Page 6 May, 2006 <br />