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

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NMD and WMD (Panels 17 -Right through 24- Right, 12 -Left through 17 -Left, 19- and 20 -Left, and 13- and 14 -Left Inby, PR 03 -06, PR06 -07, PR09 -08, TR07 -63, TR08 -64, TR09 -68, TR09 -71) Mining will continue to the northern limit of the NMD, and development will be initiated in the WMD, progessing through full development and longwall mining. Mining in the NMD and WMD will result in subsiding portions of Fish Creek and its associated Alluvial Valley Floor, isolated stock ponds, the Twentymile Sandstone, powerlines (located over the 19 -Right Panel, the 9NM entries, and paralleling RCR27), and the Union Pacific Railroad Track (located over the 12- through 17 -Right Panels). Initial development (Phase 1), Phase II, and Interim Phase III development in the WMD will be limited to main and sub -main entries, with retention of support and barrier pillars, with no subsidence over these areas. Full development and mining in the WMD under PR09 -08 and TR09 -71 will result in undermining and subsidence of Fish Creek and designated Alluvial Valley Floor areas, and various stock ponds, and has a very limited potential to affect existing springs that are outside of the Permit Area boundary. Each of these affected surface structures or resource values are discussed in the following sections. Land Use Pastureland and rangeland are the dominant land uses in this remaining section of the Northern Mining District. The land -use patterns are presented in Map 3, Premining Land Use. Existing Structures Aquifers The Twentymile Sandstone outcrops along sections of the Foidel and Middle Creek drainages. The Twentymile Sandstone is a marginal regional aquifer which extends throughout much of Northwest Colorado. There are no known water supply wells completed in the Twentymile Sandstone in the vicinity of the mine. County Roads 27 and 37A and Ranch Roads TCC will undermine and subside portions of Routt County Roads 27 (RCR27) and 37A (RCR37A) during mining of Panels 13- through 17 -Left in the WMD. RCR27 is an asphalt -paved all- weather road, while RCR37A is a gravel- surfaced secondary road. It is anticipated that a maximum of 69 inches of subsidence will occur where the existing road (RCR27) crosses the center of the longwall panels. Recognizing that subsidence will be incremental across each panel (ie: minimal over each gateroad, and gradually increasing to the maximum at the center of each 1,000 -foot wide panel), subsidence - related changes in road elevation and gradient (maximum change in gradient will be approximately 1.2 percent, or 1.2 feet per 100 feet). will probably not be noticeable. TCC has previously subsided portions of RCR27 and RCR33 in the SWMD and EMD, with no significant impacts on either the roads or their continued effective use. The roads were visually monitored during and following mining and subsidence, and some localized cracking of the asphalt surface was noted. Cracks were generally small (maximum width of 2 -3 inches), and were repaired by filling the cracks with hot tar /asphalt. Several ranch roads traverse the planned longwall panels that will be subsided by mining. Use of these roads is limited to TCC personnel and surface landowners, with no use by the general public (access controlled with locked gates. Subsidence may result in minor surface cracks, which will be repaired by regarding the roads. Powerline The powerlines located to the north of the 18 -Right gate -road and within the 19 -Right Panel (NMD), and the powerline that parallels RCR27 (WMD) will be subsided during longwall mining. The powerlines within the 19 -Right Panel are adjacent to the gate -road, and the powerline that parallels RCR27 crosses perpendicular to the 13- through 17 -Right and 19 -Right Panels. TCC's extensive experience indicates that these powerlines will not be negatively impacted. The subsidence report for the powerlines is presented in Exhibit 7e -7. Railroad The Union Pacific Railroad spur traverses over Panels 17- and 18 -Right and their associated gateroads during the five -year permit term (2003- 2008). Overburden thickness varies from 1,100 to 1,200 feet in the corridor TR09 -71 2.05 -181.9 12/30/09