2008-12-11_PERMIT FILE - C1980007A ‎(16)‎

• Permit No: C1980007A
• IBM Index Class Name: Permit File
• Doc Date: 12/11/2008
• Section_Exhibit Name: Exhibit 66 Mine Water Control Plan
• Media Type: D
• Archive: Yes

West Elk Mine - Mine Water Control Plan Mountain Coal Company
• TABLE OF CONTENTS
1.0 INTRODUCTION ..................................................................................................................1
1.1 Project Description .................................................................................. ..................1
1.2 Analysis Methods .................................................................................... ..................1
1.3 Design Criteria ......................................................................................... ..................1
2.0 SEDCAD INPUT PARAMETERS APPLICABLE TO ENTIRE PROJECT .......... ..................2
2.1 Storm Type .............................................................................................. ..................2
2.2 Rainfall Depth .......................................................................................... ..................2
2.3 Structure Naming Convention .................................................................. ..................2
3.0 SEDCAD INPUT PARAMETERS FOR SUBWATERSHEDS ............................. ..................3
3.1 Subwatershed Boundary ......................................................................... ..................3
3.2 Soil Type & Land Cover ........................................................................... ..................3
3.3 Subwatershed Hydrologic Parameters .................................................... ..................4
3.3.1 Hydrologic Soil Group ............................................................................ ....................4
3.3.2 Curve Number ........................................................................................ ....................4
3.3.3 Time of Concentration ............................................................................ ....................4
3.3.4 Muskingum Routing Parameters ............................................................ ....................4
3.3.5 Hydrograph Response Shape ................................................................ ....................5
3.4 Subwatershed Sediment Parameters ...................................................... ..................5
3.4.1 Soil Erodibility Factor, K ......................................................................... ....................5
3.4.2 Length-Slope Factor, LS ........................................................................ ....................5
3.4.3 Control Practice Factor, CP .................................................................... ....................5
3.4.4 Particle Size Distribution ........................................................................ ....................6
4.0 SEDCAD INPUT PARAMETERS FOR STRUCTURES ........................................................7
4. Ditches ...................................................................................................................... 7
4.2 Culverts .....................................................................................................................7
4.3 Muskingum Routing ...................................................................................................7
4.4 Ponds ........................................................................................................................ 7
5.0 SEDCAD OUTPUT / RESULTS ............................................................................................8
5.1 Ponds ........................................................................................................................8
5.2 Subwatersheds ...........................................................................................................8
5.3 Ditches and Culverts .................................................................................................8
5.4 Small Area Exceptions and Other Exemptions ...............................:..........................8
APPENDIX A: OUTPUT SUMMARY TABLES
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