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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 />May 22, 2013 <br />William A. Bear <br />Bowie Resources, LLC <br />P.O. Box 483 <br />Paonia, CO 81428 <br />Re: Bowie No. 2 Mine (Permit No. C- 1996 -083) <br />Technical Revision No. 75 (TR -75) <br />As -Built Configuration for Gob Pile #4 <br />3rd Adequacy Review Response <br />Dear Mr. Bear: <br />COLORADO <br />ID IV I S I O N O F <br />RECLAMATION <br />MINING <br />SAFETY <br />John W. Hickenlooper <br />Governor <br />Mike King <br />Executive Director <br />Loretta E. Pineda <br />Director <br />The Division has reviewed Bowie Resources, LLC's (BRL) third response to the Division's <br />adequacy concerns with the technical revision application submitted for the as -built <br />configuration of Gob Pile 94. One adequacy concern remained when the Division last reviewed <br />BRL's submittal, which resulted in the Division placing a stipulation on our approval of the <br />revision application. The issue was: <br />Rule 4.10.4 Coal Mine Waste Banks — Construction Requirements <br />4. The Division's initial review of the as -built topography provided with the TR -75 <br />application indicated that portions of Gob Pile #4 were constructed with steeper slopes <br />than what was approved in the original design for the pile. On an attached map <br />(attached hereon for your reference), we identified areas of the slope that appeared to <br />be between 2.0 H:1 V and 2.5 H:1 V, and other areas that were steeper than 2.0 H:1 V <br />(blue -green areas). <br />BRL contracted Buckhorn Geotech, Inc. to further examine the stability of the refuse <br />area. Buckhorn has conducted a revised As -Built Stability Analysis, and determined <br />that slopes as steep as 2.0 H: IV will provide the required Minimum Factor of Safety <br />of 1.5. However, in the Conclusions section of the memo, Buckhorn recommends, <br />"that the areas highlighted in the DRMS letter of October 31, 2012 be surveyed to <br />confirm the slopes in those areas. Any areas steeper than 2.0 H: IV should be re- <br />graded to achieve a slope with a minimum F. S. of 1.5 as required." <br />BRL will need to ground -truth the contours of Figure 2 and identify and re -grade any <br />segments steeper than 2.0 H:1 V, in order to achieve the required factor of safety. This <br />work must be completed and submitted to the Division before TR -75 can be approved, <br />Office of Office of <br />Mined Land Reclamation Denver • Grand Junction • Durango Active and Inactive Mines <br />