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STATE OF COLORADO <br />DIVISION OF RECLAMATION, MINING AND SAFETY <br />Department of Natural Resources <br />1313 Sherman St., Room 215 <br />Denver, Colorado 80203 <br />Phone: (303) 866-3567 <br />FAX: (303) 832-8106 <br />COLORADO <br />DIVISION O F <br />RECLAMATION <br />M[N[NG <br />- &- <br />SAFETY <br />June 25, 2007 8111 Ritter, Jr. <br /> Governor <br />Mr <br />Henry Barbe Harris D. Sherman <br />. <br />Mountain Coal Company LLC Executive Director <br />P <br />Box 591 <br />O Ronald W. Cottony <br />. <br />. Division DirecYOr <br />Somerset, CO 81434 Natural Resource Trustee <br />Re: West Elk Mine (Permit C-1980-007) <br />Technical Revision 109 (TR-109), Deer Creek Shaft <br />Dear Mr. Barbe: <br />The Division has reviewed the above-referenced submittal, and has the following comments. <br />1) Please add to the submittal a description of the measures that will be taken to ensure <br />compliance with Rule 4.07.3(2), which requires sealing aquifers that are penetrated in <br />drilled holes. <br />2) The proposed closure for each of the two shafts is a concrete and steel cap that will be <br />installed just below the ground surface. The cap will be covered to the ground surface <br />with material from the subsoil stockpile. The Division is concerned that a concrete and <br />steel cap which spans the shafr void will eventually deteriorate and result in a safety <br />hazard. The Division prefers and requests that the vent and escape shafts be closed by <br />backfilling them with drill cuttings (and purchased backfill, if necessary) from the <br />bottoms of the shafts up to the concrete and steel caps, and then cover the caps to the <br />ground surface with material from the subsoil stockpile. With this complete backfilling, <br />total reclamation costs for TR-109 are estimated to be $169,291, compared to $130,015 <br />for partial backfilling, as you have proposed (please see enclosed cost estimating <br />worksheets). From these two amounts, $17,060 will be deducted for the bond liability <br />associated with the three geotechnical holes on the shaft site (approved in MR-338 and <br />which will be replaced by the shafts), resulting in net new liability for TR-109 of <br />$152,231 for complete backfilling of the shafts, compazed to $112,955 for partial <br />backfilling. The complete backfilling closure method may also require a small amount of <br />additional disturbed area for long-term stockpiling of cuttings to be used as backfill, <br />which would require revising the maps in the submittal and would result in a small <br />addition to reclamation liability. <br />3) Please add to the submittal an evaluation of potential adverse impacts to MonumenYDam <br />from the proposed blasting. <br />Office of Office of <br />Mined Land Reclamation Denver Grand Junction Durango Ac[ive and InaQive Mines <br />