2018-01-31_REVISION - C2009087 (30)

Home Browse Search

The permit area varies in elevation from 6,600' to 7,800' with the portal openings at 6,690' along Little Grassy Creek. The main mine facilities lie in Sections 2 and 3, Township 5 North, Range 8 West and Sections 27, 34, and 35, Township 6 North, Range 87 West of the 6th Principal Meridian, and are located adjacent to an active surface mine excavated originally by Seneca Coal Company's ( SCC) surface mining operation (Permit No. C- 1980 -005). The post- mining land uses are rangeland, recreational use, and wildlife habitat. The Sage Creek Mine permit does not include a variance under Rules 2.06. 2 (experimental practices), 2.06.3 (mountaintop removal), and 2.06.5 (approximate original contour (AOC) for steep slope mining). No variance from contemporaneous reclamation for combined surface and underground mining operations (2.06.7) is needed due to the fact that the Seneca II Mine ceased operations in 1999 and has been reclaimed; the excavated pit accessing the Wadge Seam to construct mine portals and other facilities to support an underground mine is not considered surface mining; and the Peabody Sage Creek Mine reclamation bond includes any remaining facilities from the Seneca II Mine. Topography The proposed PSCM permit area is located in the Yampa Coal Field, on the southern margin of the Sand Wash Basin in the foothills of the Williams Fork Mountains. The Williams Fork Mountains extend about 30 miles from east to west across northwestern Colorado. Elevations in the permit area and adjacent areas are between 6,600 feet and 7,800 feet. The average elevation of the permit area is approximately 7,040 feet. Most of the permit area is covered by rolling hills with agricultural fields and rangeland. These low hills extend to higher elevation ridges and steep slopes in the eastern and southwestern parts of the permit area. The perennially flowing Grassy Creek crosses the permit area from south to north, and is joined by its two ephemeral tributaries, Little Grassy Creek and Scotchman's Gulch, near the northern boundary of the permit area (Little Grassy Creek has perennial flow in its lower part as a result of coal spoil spring inflow from Pond 002 on lands transferred from the Seneca II Mine to the PSCM.) Grassy Creek flows into the Yampa River two miles north of the permit area. The Yampa River is one of the largest tributaries of the upper Colorado River system. Geology Section 2.04.5 of the PSCM permit application describes the geology and hydrology in the permit and surrounding areas, which includes information from the following two U.S. Geological Survey Water -Resources Investigations Reports (WRIRs): Hydrology and Geochemistry of a Surface coal Mine in northwestern Colorado, WRIR 92-4187, by R.S. Williams, Jr. and G.M. Clark and Geoh,, d�gic Evaluation of the upper part of the Mesaverde Group, Northwestern Colorado, WRIR 90-420, by S.G. Robson and Michael Stewart. The PSCM permit area extends from the crest of the Tow Creek anticline westward to the axial area of the Hayden syncline. This area is on the southern edge of the regional Sand Wash structural basin. The local stratigraphic sequence that is exposed at the surface is of Cretaceous age. The sequence is, in ascending stratigraphic order, the Iles Formation, Williams Fork 5