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MMRR Quarry, M-2004-067 <br />Response to June 30 Adequacy Review (as amended) <br />August 19, 2005 <br />Page 5 <br />6. The applicant has estimated a maximum of 200,000 cubic yards of fines to be generated <br />throughout the life of the 10-year mine plan. In conformance with Rules 6.4.4(d) and 6.4.4(e)(ii), <br />please clarify the volume of fines that will be on site during a maximum disturbance scenario <br />where the fines will ultimately be used as a substrate in reclaimed areas or will be classified as <br />unusable and backfilled into the pit floor. Along with the volume estimate, please specify where <br />the fines will be located and the distance(s) they will need to be moved during final reclamation. <br />This information is needed to calculate in itemized cost for reclamation of the processing fines <br />during a maximum disturbance scenario. Please provide. <br />Fines will be generated in the processing area and stockpiled at its northern end <br />for subsequent mixing with amendments, as appropriate, and final use as a <br />substrate in the plant growth medium. Given a plan for concurrent reclamation, <br />at no time will 200,000 cubic yards of fines be stockpiled. Fines will begin to be <br />incorporated into reclaimed bench areas soon after quarry production has shifted <br />to the second bench. Based on a comparison of production rates and fines <br />generation versus area to be reclaimed at various stages of production, there will <br />be significantly less than 50,000 cubic yards of fines stockpiled at any one time. <br />Also making a conservative estimate regarding the distance that fines must be <br />transported, factoring in haul road curvature, the average one-way distance to <br />haul fines on-site is less than 1,500 feet. For the purposes of bonding, we <br />believe the maximum disturbance scenario involves hauling, at the very most, <br />50,000 cubic yards of fines a distance of 1,500 feet. <br />7. The applicant has indicated that once the pit floor is sufFciently large, additional mining below <br />the pit floor level can be accommodated ... and that mining below the finished pit floor ... Please <br />verify the maximum expected depth (and elevation) of quarry excavation, and clarify whether this <br />will result in quarry excavation below the original ground level. If quarry excavation is expected <br />below original ground elevation, please define the maximum number of feet below original ground <br />surface the excavation will be and whether this elevation will intersect or be below the expected <br />groundwater surface. Also, please verify that the reclaimed quarry floor will be graded to achieve <br />positive drainage. <br />In the March 23, 2005 submittal, the applicant indicated that additional quarry <br />material might be mined below the proposed pit floor elevation. This detail was <br />proposed primarily to accommodate the potential for additional waste rock <br />generated over the life of the mine. Based on additional analysis in the <br />intervening period, this proposal will not be necessary and the applicant hereby <br />withdraws the proposal to mine below finished pit floor elevation. <br />By definition, a mining operation extracts materials located below the original <br />ground elevation. The deepest cut proposed in the mining plan for the MMRR <br />Quarry, generally located at the base of the east wall of the mine, will be <br />approximately 425 feet from pre-mining elevation to the proposed pit floor. <br />Based on available data, it is possible that excavation to the proposed pit floor <br />elevation will intersect the existing groundwater surface. <br />The Division cited Rule 3.1.6(1)(b) in its August 2, 2005 revised adequacy letter. <br />This Rule concerns the hydrologic balance in the vicinity of mining and requires <br />