2018-08-10_GENERAL DOCUMENTS - C1982056

Home Browse Search

Four geologic formations exist in the vicinity of the Foidel Creek Mining Districts. They are, in ascending order, the Mancos Shale, the Iles and Williams Fork Formation of the Mesa verde Group, and the Lewis Shale. These strata were all deposited during the late Cretaceous Period. Generally, the strata dip to the center of the basin. Coal Seam Stratigraphy Three economically important coal seams, the Lennox, Wadge, and Wolf Creek coals, are located within the locally important Middle Coal Group of the Williams Fork Formation. At this time, the Wadge coal seam is the only seam being mined in the Foidel Creek underground mine. The Wadge Coal seam was strip mined in CYCC's adjacent Energy Mine No. 1, Energy Mine No. 2, and Eckman Park Mines (No. C-1981-071) and Energy Mine No. 3 (C-1984-062). The Wadge coal seam, in the area of the Foidel Creek Mine, is separated from the underlying Trout Creek sandstone by about 250 feet of interbedded sandstones, siltstones, shales and coals. The Wadge coal seam is separated from the overlying Twentymile sandstone by 700 feet of massive shale and interbedded sandstones, siltstones, shales and coals. Overburden depths in the current permit area range from 0 to 1,700 feet. TC also mines within the Wolf Creek Seam. TC was given approval to conduct development mining within this seam with the approval of TR83 in December of 2014. PR -10 updated the mining plan to conduct development mining and longwall mining of this seam in the 5RT to 9RT longwall panels as depicted on Maps WC -23 and WC -23B dated July 6, 2015. The Wolf Creek Coal Seam splits into four distinct benches, the combined total seam thickness ranges from 7.5 to 14 feet. Between the Wadge Coal Seam and the Wolf Creek Seams, there is interbedded sandstone and shales. Interbedded sandstones and shales and the massive Trout Creek Sandstone are below the Wolf Creek Seam. Surface Water H.. d�gy The mine is located in the upper reaches of the Yampa River Basin. The permit area and adjacent areas are drained by Foidel Creek, an intermittent stream, and Fish Creek and Middle Creek, both perennial streams. Fish Creek drains east into Trout Creek whereas Foidel Creek drains northeast to Middle Creek before Middle Creek joins Trout Creek. The quality of water in the Fish Creek and Foidel Creek drainages has been affected previously by surface mining upstream and downstream of the underground mine's existing surface facilities. Alluvial valley floors are identified downstream of the mining area at the confluence of Foidel and Middle Creek, and on Trout Creek from its confluence with Middle Creek downstream to the Yampa River. Permit Revision No. 3 declassified portions of Foidel and Middle creeks previously classified as AVF's. Detailed discussion concerning alluvial valley floors can be found in Section B, part XVIII of this document as well as Exhibit 7j of the permit. Ground Water H. dr�g_y The stratigraphy and geologic structure within the Twentymile Park Synclinal Basin control the ground water flow within the permit and adjacent areas. There are three regional bedrock aquifers within the permit and adjacent areas of the Foidel Creek underground mine. These Foidel Creek Mine 9 August 10, 2018