GENERAL41258 - Laserfiche WebLink

Home Browse Search

The overburden proposed as non-toxic cover at Red Canyon is clayey and moderately saline (Table 2.04 .9(1)(b)-4: Site No. 0-6 and 0-7). The material is clay, with one EC value of 5.6 (0-7). SAR values are very low and pH ranges from moderately acidic (4.6) to slightly alkaline (8.0). The material is conditionally suitable for non-toxic refuse cover (see also C.S.U. soils analytical evaluation, Figure 2.04.9(1)(d)-1) if acidic materials are neutralized. This material was replaced to a depth of four feet over the underground development waste pile, and is the only area proposed to have topsoil replacement. All previously disturbed areas will use overburden as a substitute for topsoil. V. Sealing of Drilled Holes and Underground Openings Grand Mesa Coal Company is prudently managing holes, wells and piezometere prior to sealing them. The Division requires that each hole, well or other underground opening be capped, sealed, backfilled, or otherwise properly managed (4.07.3). VI. Use of Exnlosivee A. Use of explosives at the Red Canyon Mine was minimal during underground operatione_ There are currently no explosives used at the site; therefore this section does not apply (4.08). VII. Disposal of Excess Snoil A. The Red Canyon Mine will not require a disposal area for excess spoil (4.09) . VIII. Coal Mine Waste Banks A. The Division approved the use of a disposal area for underground development waste. This waste dump is located east of the creek in an area of previously mined strip pits. The proposed design specified that the pile would move eastward into undisturbed land. Original designs proposed the placement of 30,000 yd' per year, for a total of 159,000 tons of underground development waste. Ultimately, 50,000 yards were placed at the site. B. The Division has reviewed the design for the fill and proposes to approve it. The design specifications for Che underground development waste pile may be found in Appendices B and D of the permit application (4.09.1(2)). C. The Division proposes to approve the use of a straw mulch to control erosion, promote growth, and increase moisture retention on the reclaimed underground development waste pile (4.09.1(4)). D. The Division proposes to approve the location of the disposal area (4.09.1(6)). E. The applicant submitted a plan for disposal of Hotchkiss Coal Yard waste on July 25, 1984, at the approved underground waste development disposal area within the permit boundary. GMCC accepted 7,000 tons during the summer of 1984. The applicant had demonstrated that disposal of such materials would not adversely affect water quality or flow, vegetation, public health, or stability of the disposal area based on hydrologic, geotechnical, physical, and chemical analyses. Therefore, the Division approved disposal of these materials (4.10.1(2)). The Red Canyon underground development waste pile has no sub-drainage system. The lower section of the waste pile was constructed in an abandoned pit. T'he Division finds that this alternative ensures the 19