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ENERGY COMPANY <br />P.O. BOX 467 GOLDEN, COLORADO 80402 <br />April 22, 2009 <br />Ms. Janet Binns <br />Division of Reclamation, Mining & Safety <br />Department of Natural Resources <br />1313 Sherman Street, Room 215 <br />Denver, Colorado 80203 r' 0 <br />Re: Technical Revision No 40 <br />Modification of Final Contours -Long Term Spoil Area <br />piv1tA ring and VOW n, <br />Dear Ms. Binns: <br />Coors Energy Company (CEC) is requesting consideration by the Colorado Division of <br />Reclamation Mining and Safety (DRMS) for a Technical Revision to Permit C-1981-028. The <br />effect of this Technical Revision (TR) will be to modify the final contour over the Long Term <br />Spoil Area (LTSA), only. The submittal is offered following lengthy discussion and review of <br />the material balance across the LTSA, the receipt of recently updated site-life calculations, and <br />general grading observations as portions of the LTSA were re-contoured to match the advance of <br />the B-Pit fill activity. <br />With the earlier processing and approval of Technical Revision No. 34, CEC was attempting to <br />address what, at the time was considered to be an amount of material in excess of the reclamation <br />requirements across the LTSA. CEC subsequently made a change in engineering support <br />services, and this change led to significant advancements in mapping support. The increased <br />reliability and repeatability of the data, has convinced CEC that while the earlier change was in <br />the right direction, it was too extreme, resulting in a higher than necessary relief configuration <br />across the LTSA, and a potential shortage of material for the effective final cover of B-Pit. <br />Through its submittal of this Technical Revision 40, CEC is asking for DRMS concurrence with a <br />reduction in the impact of the previous TR; to increase and insure there is an adequate amount of <br />spoil material for B-Pit final cover, and to accomplish this without significantly altering (by less <br />than one foot, on average) the final contour across the LTSA. <br />We have enclosed, as supporting documentation, (3 copies each of) a summary page for <br />Technical Revision 40, an evaluation by American Environmental Consulting LLC, consultant to