2013-10-17_PERMIT FILE - C1982056A ‎(4)‎

• Permit No: C1982056A
• IBM Index Class Name: Permit File
• Doc Date: 10/17/2013
• Doc Name: Pages 2.05-65 to 2.05-197.3 part 2
• Section_Exhibit Name: 2.05 Operation and Reclamation Plans Part 2
• Media Type: D
• Archive: Yes

The final area to be impacted by subsidence is associated with mining of the 16 -Right Panel. The State of
Colorado is the surface owner of the parcel to be undermined and subsided. As presented above, a total of 4
acres will be flooded by the mining of this panel. As is the case for all lands along Fish Creek to be undermined
and subsided, no flood irrigation system has been established to increase the productivity of the land nor are
management practices established for haying this area. The land is treated as unimproved rangeland, utilized for
grazing by TCC's grazing lessee.
Ashley Impoundment and Irrigation Ditch - The Ashley impoundment is located in the SW /4SW /4 of Section
15, TSN, R86W. This impoundment is of earthen construction, and typically holds water throughout the year.
The headgate for the irrigation ditch is located in the SEANE /4 of Section 19, TSN, R86W. TCC has
undermined and subsided sediment ponds during the mining of reserves located in the west part of the Permit
Area. No material damage to the ponds resulted from mining activities. It is anticipated that the Ashley
impoundment will react in the same manner. If cracks develop in the embankment, they will be repaired and
regraded, to maintain the integrity of the impoundment.
In reference to the smaller impoundment, TCC does not plan any maintenance for this structure due to its
current poor condition. If the owner repairs and upgrades it prior to mining, TCC will perform any necessary
repairs, as needed.
NMD and WMD (Panels 17- through 24 - Right and 12- through 17 -Left, PR 03 -06, PR06 -07 and PR09 -08)
Proposed mining in the remaining portion of the NMD, and longwall mining of the WMD reserves should not
result in material damage or diminution of reasonably foreseeable use of structures or resources. Structures
which will be undermined and subsided include portions of County Roads 27 and 37A, ranch roads, powerlines
(Public Service, Western Area Power Association, Tri- State, and Yampa Valley Electric Assn.), portions of the
Union Pacific Railroad Spur (formerly Denver & Rio Grande), Fish Creek and its associated Alluvial Valley
Floor areas, several stock ponds, TCC monitoring wells and surface water monitoring sites, and portions of the
Twentymile Sandstone, as a natural feature. It should be noted that mining - related subsidence is not expected to
impact the proposed 6MN Reservoir, since the Reservoir is entirely outside of the projected subsidence limits,
and the Reservoir embankment is a minimum of 540 feet from the nearest supported mine workings
(development entries) and 1,250 feet to the nearest projected subsidence limit line (refer to 6MN Storage
Reservoir — distance from Embankment Structure to Current and Future Supported and Subsided Mine
Workings, Exhibit 490).
Aquifers - The Twentymile Sandstone is the only regional aquifer above the coal seam. It is not anticipated that
any water supply wells will be impacted from undermining of the Twentymile Sandstone, since no supply wells
in the Twentymile Sandstone exist in the affected area. TCC's ongoing hydrologic monitoring program does
not show any impacts to this formation outside of the mining area.
County Roads 27 and 37A and Ranch Roads - Relative to the response of existing roads to undermining and
subsidence, TCC has gained considerable applicable local experience through previous undermining of RCR27
and RCR33 in the SWMD and EMb. Experience confirms that subsidence does not significantly change road
configuration or disrupt use of the road, since any resulting changes in road elevation and gradient are gradual
and incremental. While asphalt pavements are somewhat flexible, any significant changes in elevation/gradient
may result in tensile or compressive forces that may cause localized cracking or buckling of the road surface. In
either case, gravel can be placed as a temporary repair, then hot tar or asphalt can be used to fill any cracks or
voids. For larger areas of cracking or buckling, or where heavy loads or traffic is anticipated, a permanent
asphalt overlay may be appropriate. Ranch roads are either dirt- or gravel- surfaced. Any damage to these roads
can be readily repaired by regrading the road. Any necessary temporary and permanent repairs, assure that
material damage or diminution of reasonably foreseeable use of roads does not occur.
For a segment of RCR33 overlying the 9 -Right Longwall Panel that was damaged by subsidence, temporary
placement of gravel allowed continued use of the road, and an asphalt patch returned the road to a condition
comparable to its premining condition. Where RCR33 crossed the 8 -Right Panel, subsidence caused the road to
buckle. The damaged area was excavated, gravel was placed as a temporary repair, and following completion of
PR09 -08 2.05 -184.7 04/29/09