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MMRR Quarry, M-2004-067 <br />Response to Jan. 27 Adequacy Review <br />March 23, 2005 <br />Page 6 <br />Sizing criteria for all ponds is provided. This information is based on <br />hydrologic and hydraulic computations in the project engineer's memo and <br />drawing revisions. <br />Drainage Design Inputs. The technical response to this review comment <br />is definitively provided by the memorandum of the project engineer. The <br />present memorandum summarizes responses to the regulatory drainage <br />design issues that are property addressed in the current Regular 112 <br />reclamation permit review process. <br />We have produced a design for the MMRR Quarry that is safe to the <br />standards enforced by the DMG under its performance standards. The <br />discussion of Exhibit C-2 above notes that the project engineer and DMG <br />specialist held a meeting to discuss standards. The result of those <br />discussions was agreement to use various storm events as design <br />standards for mining and reclamation functions. The engineering memo <br />and revised plans demonstrate that temporary structures mitigate an <br />appropriate level of risk over the life of the mine. Permanent structures <br />would conform to the standard 100-year storm as the mitigation standard <br />for any permanent land development impact, but none are necessary to <br />effectively reclaim the site for post-mining land use. <br />Blasting Plan. This adequacy comment references geotechnical stability <br />comments submitted by Allen Sorenson. Following the format of the <br />adequacy review, the response to this issue is covered under Rule 6.5, <br />below. <br />Uranium Mineralization. It is important to note with regard to uranium <br />mineralization that there is a wide potential for difference between the <br />public perception of mining risks and reliable scientific evidence of <br />hazardous airborne matter or runoff incidentally contaminated by mining in <br />a general area of uranium mineralization. The intent of the MMRR Quarry <br />is not to release uranium or any other toxic agent, nor is it the intent of the <br />quarry to act with disregard for the appropriate level of vigilance. A <br />reasonable plan to mitigate potential hazards associated with uranium <br />mineralization is presented in the DMG's adequacy letter, and we adopt <br />that plan with minor adjustments and commentary as discussed below. <br />For the record, the MMRR Quarry site is on the fringe of an area of <br />uranium mineralization stretching through the eastern part of Gilpin <br />County. We reviewed the DMG record for another rock quarry located in a <br />relatively similar position on the fringe of this belt of uranium mineralization <br />and found no evidence of technical review, operations standards, <br />