2021-04-01_REVISION - M1977144 - Laserfiche WebLink

Home Browse Search

Colorado Quarries, Inc. 270 S. 15th St. Canon City, CO 81212 RECEIVED March 25, 2021 APR 012021 Tim Cazier DIVISION OF RECLAMATION vision of Reclamation, Mining and Safety MINING AND SAFETY 1313 Sherman St., Room 215 Denver, CO 80203 Re: Mica Lode, Permit M-1977-144,TR-01, Preliminary Adequacy Review Responses Dear Mr. Cazier, We have received your preliminary adequacy review letter, and have the following responses, numbered the same as your questions and questions. 1. Though you stated that no response to this item was necessary, we felt that a clarification would help. We defined a revised boundary, which is to incorporate a total 46 acres, comprised of affected areas and non-disturbed areas. The revised maps we submitted were digitally generated,and designed to be viewed and printed at a scale appropriate for this revision. As such, the acreage discrepancies you noted were due to shifting the non-disturbed area boundary lines slightly such that they would be visible clearly, and not overlain (and not clearly depicted) by the outer permit boundary line. The kmz data obviously reflects these shifted visible boundary lines. Colorado Quarries understands that affected area boundaries of a 112 permit must be marked, and will ensure that they are marked on the ground. 2. The highwall configurations should be considered thus: Smooth slopes (un-benched)will be 2.5H:1V or gentler, as defined in both Exhibit D or E. Benched slopes will be defined by the dimensions of 40-foot tall wall at 1.25:1 gradient, alternating with gently-sloped 25-foot wide benches. To clarify, only the walls are 1.25H:1V. Level benches will be constructed from competent rock, and will be made to be gently sloping from placement of fines and growth medium. Therefore,the overall gradient of the slopes and benches will be 1.9H:1V. A cross- section diagram is provided with this response letter. 3. The slope of the Ruby Pit,where competent walls and benches cannot be constructed, will be 2.5:1. Any other gradient stated in the initial submittal was in error. The Ruby Pit will potentially have both smooth and benched highwall slopes, based on the nature of the rock exposed during future excavation. We do not know at this time how much of either type of highwall there will be, since we do not know how extensive the excavation in that affected area will be, nor the nature of the rock in the final surfaces at the time of reclamation. 4. The statement that there may be a pond in the Ruby Pit after it is excavated is from the plan at the time of the permit conversion. We commit to no pond in the Ruby Pit under this permit.