Laserfiche WebLink
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 />To: Travis Marshall <br />From: Tim Cazier, P.E. <br />Date: October 27, 2011 <br />Mined Land Reclamation <br />MEMORANDUM <br />STATE OF COLORADO <br />Re: Craig Ranch Pit — Response to Adequacy Stormwater Comments, Permit No. <br />M- 1986 -002 / CN -01 <br />COLORADO <br />D I V I S I O N O F <br />RECLAMATION <br />MINING <br />— &— <br />SAFETY <br />John W. Hickenlooper <br />Govemor <br />Mike King <br />Executive Director <br />Loretta Pineda <br />Director <br />The Division of Reclamation, Mining and Safety (Division) engineering staff has completed its <br />review of the August 25, 2011 of the Craig Ranch submittal with respect to stormwater <br />management of the subject project. The review included: <br />A) 112 Permit Application to The Colorado Division of Reclamation, Mining, and Safety by <br />Greg Lewicki and Associates, revised August 2011 (Application); <br />B) July 13, 2011 Letter from Ryan Ellis to Travis Marshall re Craig Ranch Pit — Stormwater <br />Response, Permit # M- 1986 - 002 /CN -01 (Ellis Letter); and <br />C) August 25, 2011 Letter from Ben Langenfeld to Travis Marshall re Craig Ranch Pit — <br />Stormwater Response, Permit # M- 1986 - 002 /CN -01 (Langenfeld Letter). <br />The following comments are based on the concurrent review of the above documents (including <br />the maps, figures and calculations). The intent of these comments are to: reduce to the extent <br />practical the disturbance to the hydrologic balance in accordance with Rules 3.1.6 and 6.3.3; and <br />ensure a consistent understanding of the engineering approach, assumptions, and design of the <br />stormwater management system. <br />1. Page D -5, fourth paragraph: This paragraph describes collection ditches to be placed on <br />the northern most portion of the mining area and states these ditches will be placed "to <br />ensure that no stormwater is allowed to leave the site during mining." This statement has <br />not been revised to indicate the collection ditches are designed to convey the runoff from <br />the 100 -year, 24 -hour precipitation event. This statement should be revised, so as not to <br />imply the ditches are intended to control runoff from the PMP. <br />2. Map C -2 is referenced on page D -5, fourth paragraph to indicate the location of <br />collection ditches in the northern most portion of the mining area. There are no ditches <br />shown on Map C -2. Please revise the text to refer to Map G, or revise Map C -2 to <br />include the collection ditches. <br />Office of Office of <br />Denver • Grand Junction • Durango Active and Inactive Mines <br />