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<br /> <br />Stipulation No. lc required designs for inflow ditches to the Moffat area <br />sediment pond. These designs were submitted and approved by the Division <br />prior to construction of the diversions. <br />Stipulation No. 3 required demonstrations that convert slopes on the reclaimed <br />Moffat area could be stabilized. Pittsburgh and Midway committed to the use <br />of a number of erosion control and stablization practices, as required, in <br />Section 3.4 of the permit application package. <br />Summary of the Review Process <br />Permit Revision No. 2 resulted from a settlement agreement between the <br />Pittsburg and Midway Coal Mining Company and the Division, concerning Notices <br />of Violation C-90-043, C-90-044, and C-90-057. The agreement was approved by <br />the Mined Land Reclamation Board on March 27, 1991. The revision was <br />submitted by Pittsburg & Midway on April 19, 1991 in accordance with the <br />agreement, and was deemed complete by the Division on April 26, 1991. The <br />Division completed its preliminary adequacy review on June 10, 1991, and the <br />applicant submitted responses on July 1, 1991. Additional information was <br />received from the applicant on September 3, 1991. Publication of this <br />proposed decision by the Division begins a 30-day public comment period, after <br />which the decision becomes final if there are no objections. <br />Description of the Environment <br />The West Ridge of the Edna Mine is an area of approximately 600 acres located <br />in the west and southwest portions of the mine property. Portions of the West <br />Ridge were mined prior to passage of the Surface Mining Control and <br />Reclamation Act (SMCRA), and were reclaimed without application of topsoil. <br />At the time of this proposed decision, the final pit opening is being <br />reclaimed by the permittee. The area is characterized by long north to <br />northwest facing slopes up to fifteen percent, with varying degrees of <br />vegetative cover. Portions of the reclaimed area drain to a diversion which <br />parallels Trout Creek on the west, while other portions drain to the Center <br />Ridge Drainage on the east side. Both structures then convey runoff to the <br />West Ridge sediment pond (NPDES Point 002). This revision addresses terrace <br />structures to be constructed throughout the West Ridge reclaimed area, and <br />check dams to be constructed along the Center Ridge drainage. <br />Description of the Operation and Reclamation Plan <br />The hydrologic stabilization plan proposed in Permit Revision No. 2 entails <br />the use of check dams and terraces which were designed to control surface <br />water runoff on the West Ridge area of the mine in an attempt to minimize <br />erosion and further stabilize the reclaimed slopes. Twenty-three earthen <br />check dams with rock armoring will be installed in the drainage between West <br />Ridge and Center Ridge. These dams will have spillways designed to safely <br />pass storm runoff from a 100-year, 24-hour storm. Fourteen terraces will be <br />installed on the reclaimed West Ridge slopes at a spacing of 300-600 feet, <br />with a flow gradient of 1.5 degrees. <br />-2- <br />