2019-12-13_REVISION - M1980244 ‎(55)‎

• Permit No: M1980244
• IBM Index Class Name: Revision
• Doc Date: 12/13/2019
• Doc Name Note: Appendix 3
• Doc Name: Request For Amendment To Permit
• From: CC&V
• To: DRMS
• Type & Sequence: AM13
• Email Name: TC1
• Email Name: MAC
• Email Name: BFB
• Email Name: ERR
• Email Name: JPL
• Media Type: D
• Archive: No

TABLE OF CONTENTS
1. INTRODUCTION........................................................................................................................ 1
2. ASSUMED CONDITIONS OF THE FACILITIES AT CLOSURE........................................................ 1
2.1. East Cresson Overburden Storage Area........................................................................... 1
2.2. Wild Horse Extension Pit Backfill ..................................................................................... 1
2.3. Squaw Gulch Overburden Storage Area .......................................................................... 2
2.4. Valley Leach Facility 2....................................................................................................... 2
2.5. Valley Leach Facility 1....................................................................................................... 2
2.6. Schist Island Backfill ......................................................................................................... 2
3. STORMWATER MANAGEMENT ............................................................................................... 3
3.1. East Cresson Overburden Storage Area........................................................................... 5
3.2. Wild Horse Extension Pit Backfill ..................................................................................... 5
3.3. Squaw Gulch Overburden Storage Area .......................................................................... 5
3.4. Valley Leach Facility 2....................................................................................................... 6
3.5. Valley Leach Facility 1....................................................................................................... 6
3.6. Schist Island Backfill ......................................................................................................... 7
3.7. Intermediate Bench Channels.......................................................................................... 7
4. CLOSURE COST ESTIMATES...................................................................................................... 8
5. REFERENCES ........................................................................................................................ 8
LIST OF TABLES
Table 1: Summary of Hydrological Analysis.................................................................................... 3
Table 2: Summary of Intermediate Bench Chanel Dimensions...................................................... 8
Table 3: Cost Estimate Summary.................................................................................................... 8
LIST OF FIGURES(ATTACHED)
Figure 1: Site Plan
Figure 2: East Cresson OSA Closure Plan
Figure 3: WHEX Pit Closure Plan
Figure 4: Squaw Gulch OSA Closure Plan
Figure 5: Squaw Gulch VLF (VLF2) Closure Plan
Figure 6: Arequa Gulch VLF (VLF1) Closure Plan
Figure 7: Schist Island Backfill Closure Plan
Figure 8: Typical Sections and Details
LIST OF APPENDICES
Appendix A: VLF and OSA's Diversion Channel's Design at Closure
Appendix B: HEC-HMS Calculation
Appendix C: Closure Diversion Channel Drawings
Appendix D: Closure Cost Estimates