Laserfiche WebLink
III IIIIIIIIIIIII III • <br />999 <br />Draft Geotechnical Findings <br />•, <br />~~ <br />Foidel Creek Permit Application <br />XVI. Explosives (2.05.3(b), 4.08) <br />Colorado Yampa Coal Company proposes to conduct blasting operations within 500 <br />feet of several potentially sensitive facilities, including subsurface <br />gasoline storage tanks, an electrical substation and a 69,000 volt overhead <br />electrical powerline. However, the applicant will exercise special <br />precautions to clear the area of all personnel prior to blasting operation. <br />Gasoline subsurface storage facilities will be precisely inventoried to detect <br />any leakage which might occur. Stemming design should limit flyrock <br />generation and blast loading will be limited to less than 440 pounds per 8 <br />second delay. Vibrational analyses completed on the subject property have <br />determined that this loading will limit peak particle velocities at the <br />location of the critical storage facilities to less than 0.52 inches per <br />second. The electrical substation and the 69,000 volt electrical powerline <br />have been relocated, as depicted on Map TR-2a of the technical revision of <br />Permit 79-177. The Division finds that the blasting plans within the Foidel <br />Creek permit application conform with the requirements of Rules 2.05.3(b) and <br />4.08. <br />XVII. Backfillina and Grading (2.05.3(61(bl. 2.05.3(91. 2. <br />The proposed Foidel Creek underground mine portals will be faced-up from an <br />existing surface mine pit low-wall. The applicant proposes to reconfigure the <br />existing low-wall and the existing backfilled spoil slopes which comprise the <br />opposite face of the existing surface pit. Exhibit 8 of the permit <br />application presents thorough and prudent state-of-the-art stability analyses <br />of the proposed reconfiguration for the surface facility area. Approximately <br />660,000 cubic yards of spoil will be removed to decrease the existing slope <br />gradients within the existing surface pit and will be temporarily stored in <br />several embankments, upon which light load facilities and storage yards will <br />be constructed. The reader is referred to Section XXIV of these findings for <br />a more detailed discussion of these geotechnical issues. <br />Following cessation of underground mining within the Foidel Creek mine, the <br />applicant proposes to backfill the existing surface pit portal facility area. <br />Previously mined spoils existing within areas adjoining the surface facility <br />area will be used to completely backfill the existing pit to the approximate <br />original contour. <br />-(ADD COMMENTS AT THIS POINT REGARDING HANDLING OF ACID OR TOXIC FORMING <br />MATERIALS)- <br />The applicant has requested a delay of contemporaneous reclamation within the <br />surface pit area to facilitate the construction of the proposed Foidel Creek <br />portals and the supporting surface facilities. The reader is referred to <br />Section XXIV of these findings for a more detailed discussion of the delay of <br />contemporaneous reclamation variance request. <br />