Laserfiche WebLink
Meridian, and are located adjacent to a now terminated and reclaimed surface mine excavated <br /> originally by Seneca Coal Company' s (SCC) surface mining operation (Permit No. C-1980- <br /> 005). <br /> The post-mining land uses are rangeland, recreational use, and wildlife habitat. <br /> The PSCM permit does not include a variance under Rules 2.06. 2 (experimental practices), <br /> 2.06.3 (mountaintop removal), or 2.06.5 (approximate original contour(AOC)) for steep slope <br /> mining). No variance from contemporaneous reclamation for combined surface and <br /> underground mining operations (2.06.7) is needed as the Seneca II Mine ceased operations in <br /> 1999 and has been reclaimed and terminated; the excavated pit accessing the Wadge coal seam <br /> to construct mine portals and other facilities to support an underground mine is not considered <br /> surface mining; and the PSCM reclamation bond includes any remaining facilities from the <br /> Seneca II Mine. <br /> Topogrqphy <br /> The PSCM permit area is located in the Yampa Coal Field, on the southern margin of the Sand <br /> Wash Basin in the foothills of the Williams Fork Mountains. The Williams Fork Mountains <br /> extend approximately 30 miles from east to west across northwestern Colorado. Elevations in <br /> the permit area and adjacent areas are between 6,600 feet and 7,800 feet. The average elevation <br /> of the permit area is approximately 7,040 feet. Most of the permit area is covered by rolling hills <br /> with agricultural fields and rangeland. These low hills extend to higher elevation ridges and <br /> steep slopes in the eastern and southwestern parts of the permit area. The perennially flowing <br /> Grassy Creek crosses the permit area from south to north, and is joined by its two ephemeral <br /> tributaries, Little Grassy Creek and Scotchman's Gulch, near the northern boundary of the permit <br /> area. The lower portion of Little Grassy Creek within the permit boundary has perennial flow as <br /> a result of coal spoil spring inflow from Pond 002 on lands transferred from the Seneca II Mine <br /> to the PSCM. Grassy Creek flows into the Yampa River two miles north of the permit area. The <br /> Yampa River is one of the largest tributaries of the upper Colorado River system. <br /> Geology <br /> Section 2.04.5 of the PSCM permit application describes the geology and hydrology in the <br /> permit and surrounding areas, which includes information from the following two U.S. <br /> Geological Survey Water-Resources Investigations Reports (WRIRs): Hydrology and <br /> Geochemistry of a Surface coal Mine in northwestern Colorado, WRIR 92-4187, by R.S. <br /> Williams, Jr. and G.M. Clark and Geohydrologic Evaluation of the upper part of the Mesaverde <br /> Group, Northwestern Colorado, WRIR 90-420, by S.G. Robson and Michael Stewart. <br /> The PSCM permit area extends from the crest of the Tow Creek anticline westward to the axial <br /> area of the Hayden syncline. This area is on the southern edge of the regional Sand Wash <br /> structural basin. The local stratigraphic sequence exposed at the surface is of Cretaceous age. <br /> The sequence is, in ascending stratigraphic order, the Iles Formation, Williams Fork Formation, <br /> and Lewis Shale. The Iles and Williams Fork Formations are part of the regionally extensive <br /> Mesaverde Group. Quaternary alluvial deposits, generally derived from the Mesaverde Group, <br /> 4 <br />