2013-08-06_REVISION - C1996083 (3)

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MM C-0 an J. E. STOVER & ASSOCIATES, INC. 2352 NORTH 7T" STREEET, UNIT B GRAND JUNCTION, COLORADO 81501 PHONE: (970) 245 -4101, FAX: (970) 242 -7908 MINE ENGINEERING MINE RECLAMATION July 31, 2013 Susan Burgmaier AUG 8 6 2013 Division of Reclamation, Mining & Safety Division of Reclamation, 1313 Sherman St., Room 215 Mining & Safety Denver, CO 80203 Re: Bowie Resources, LLC, Bowie No. 2 Mine Technical Revision #81, Drainage Revision, Topo Update Permit C- 1996 -083 Dear Ms. Burgmaier: CIVIL ENGINEERING CONST. MANAGEMENT On behalf of Bowie Resources, LLC, enclosed is an application for a technical revision to incorporate a changes to the drainage configuration, pond sizing, and gob pile #2/ #4 topography. Sediment Pond F is at the toe of coal mine waste pile #2 and is permitted to receive runoff from gob piles #2 and #4. While the approved design is adequate and in accordance with DRMS rules and regulations, the pond has required sediment clean out on an annual basis, even though the sediment storage design is for two years. To provide for more sediment storage, the configuration of Pond F has been revised. There is a section of the southern edge of the pond that currently bows out at approximately 2.6H:1V. This revision will grade the point back at a 2H:1V in order to increase the size of the pond and allow for more sediment storage. The configuration of the gob pile terraces in the TR -76 expansion area has been slightly revised. The configuration as approved with TR -76 was fifty foot vertical spacing between terraces and one sixty foot spacing between terraces. Over the last few months, more detailed on the ground surveys have been conducted and therefore, to tie into existing ground, and provide for positive drainage, the bench configurations have been revised from fifty foot to sixty foot spacing between nearly all terraces. Also, in one small area on the second bench, between ditches F5 and F2 the slope has been revised from a 3h:1v to a 2.5h:1v. A revised stability analysis is included for the revised slope configuration and terrace spacing (specifically pertaining to Sections A -A' and F -F'). For convenience, I have sent a copy directly to Marcia Talvitie in the DRMS Durango office.