2015-03-23_REVISION - C1982056 ‎(3)‎

• Permit No: C1982056
• IBM Index Class Name: Revision
• Doc Date: 3/23/2015
• Doc Name: Exhibit 7K Wolf Creek Reserve Subsidence Evaluation
• From: Twentymile Coal, LLC
• To: DRMS
• Type & Sequence: PR10
• Email Name: JLE
• Email Name: DIH
• Media Type: D
• Archive: No

SubTerra, Inc. Peabody Twentymile Coal, LLC 03/16/2015
Foidel Creek Mine
Permit Revision 14 -11 for Longwall Mining in the Wolf Creek Seam - Subsidence Evaluation
TABLE OF CONTENTS
Section Description Page
No. No.
1. INTRODUCTION .................................................................................... ..............................1
1.1.
Prior Work ........................................................................................... ..............................1
1.2.
Foidel Creek Mine Layout in the Wolf Creek Seam ............................. ..............................2
1.3.
Pre and Post Mining Land Uses .......................................................... ..............................2
1.4.
Potential Subsidence Impact Evaluation ............................................. ..............................2
1.5.
Closure ............................................................................................... ..............................2
2.
MINE SUBSIDENCE .............................................................................. ..............................3
2.1.
Subsidence Mechanics ....................................................................... ..............................3
2.2.
Subsidence Prediction ......................................................................... ..............................4
3.
EVALUATION OF POTENTIAL IMPACTS TO THE ENERGY SPUR .... ..............................6
3.1.
Scope of Work ..................................................................................... ..............................6
3.2.
Approach ............................................................................................. ..............................6
3.3.
Subsidence Prediction ......................................................................... ..............................7
3.4.
Candidate Remedial Actions ............................................................... ..............................7
3.4.1. Remedial Planning ....................................................................... ..............................7
3.4.2. Possible Effects of Planned Remediation on Fish Creek and Its AVF .........................8
4.
EVALUATION OF POTENTIAL IMPACTS TO COUNTY ROAD 33 ....... ..............................9
4.1.
Scope of Work ..................................................................................... ..............................9
4.2.
Approach ............................................................................................. ..............................9
4.3.
Subsidence Prediction ......................................................................... ..............................9
5.
EVALUATION OF IMPACTS TO FISH, FOIDEL, AND MIDDLE CREEKS AND THEIR
ALLUVIAL VALLEY FLOORS ( AVFS) ............................................................ .............................10
5.1.
Scope of Work .................................................................................... .............................10
5.2.
Subsidence Prediction ........................................................................ .............................10
5.3.
Predicted Impacts to the AVF ............................................................. .............................11
5.3.1. Increase in Fish Creek's Surface Area ........................................ .............................11
5.3.2. Increase in Foidel Creek's Surface Area ..................................... .............................11
5.3.3. Increase in Middle Creek's Surface Area .................................... .............................12
5.3.4. Potential for Fissure Development and Water Loss (or Stream Pirating) ..................12
5.4.
Monitoring Requirements ................................................................... .............................12
6.
EVALUATION OF POTENTIAL IMPACTS TO POWERLINES ............. .............................13
i PN: 2013 -26