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STATE OF COLOR4D0 AIf HnRll U. InMM. env non n~ III III III IIIIIII III <br />999 <br />DEPARTMENT OF NATURAL RESOURCES <br />D. Monte Pascoe, E>tecutive Director <br />MINED LANb RECLAMATION <br />423 Centennial Building. 1313 Sherman Street <br />Denver, Colorado 80203 Tel. (303) 639-3567 <br />David C. Shelton <br />Director <br />April 29, 1981 <br />TO: Dan Mathews <br />Reclamation Specialist <br />FROM: Jim Pendleton <br />Senior Geologist <br />RE: Refuse Disposal, Backfill and Grading and Subsidence Aspects of the <br />Bear Coal Company Permanent Program Permit Application <br />Pursuant to your request, I have completed a review of the refuse <br />disposal, backfill and grading and subsidence sections of Bear Coal <br />Company's permanent program permit application. I forward the following <br />comments for your consideration. <br />Refuse Disposal <br />The permit application observes that refuse disposal rules are not <br />applicable. (Page 66 and 67) Bowever, staff site inspections and <br />examinations of existing stereographic aerial photography of the <br />Bear Coal Mine site suggests that some refuse has been deposited bn <br />site. Further, the application also states; "Coal cleaned up at the <br />mine site will be sold prior to the final covering of the disposal <br />area." (Page 67) Any waste now on site will have to be properly <br />addressed within the application. <br />Backfillina and Gradi <br />The application states; "Backfilling the portals will entail filling <br />ten to twenty feet out by a double solid block wall which wilt be <br />constructed in portal entries." (Page 70) In accordance with Rule <br />4.14 the portal areas should be returned to approximate original contour, <br />if it can be accomplished with a minimum static slope safety factor of <br />1.3. The applicant must perform a stability analysis of the proposed <br />backfill configuration in order to demonstrate conformance with Rule 4.14.2(Z)(b). <br />This stability analysis must consider both portal highwall cut slope as <br />well as the portal bench fill embankment. <br />Subsidence <br />The application observes that no structures exist within the potentially <br />affected area and that potential affected renewable resource Iands are <br />limited to Bear Coal Company's water supply system. You should seek <br />Roy Cox's assistance in judging the accuracy of this statement. <br />/. ,. tl <br />