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Mr. Bill Tezak <br /> April 8, 2022 <br /> Page 4 of 11 <br /> DRMS will require that the final proposed permit boundary and/or affected area be accurately shown on all <br /> maps, and that at least one map showing the corners defining that boundary, and correlating GPS coordinates <br /> for those corners, be provided. <br /> EXHIBIT D -Mining Plan (Rule 6.4.4): The mining plan shall supply the following information, correlated <br /> with the affected lands, map(s) and timetables: Please review, consolidate, and update as needed the <br /> information provided by the initial submittal and all adequacy responses to-date. <br /> (a)Provide a description of the method(s) of mining to be employed in each stage of the operation as related to <br /> any surface disturbance on affected lands; What is the proposed configuration of the benches to be created <br /> within the expanded mine area (feet wide by feet high)? <br /> Rule 3.1.10(3) states "If the Operator's choice of reclamation is for rangeland, the land shall be restored to <br /> slopes commensurate with the proposed land use and shall not be too steep to be traversed by livestock..." <br /> DRMS normally requires an overall slope of no steeper than 3:1 for rangeland reclamation. A 3:1 slope is <br /> able to be traversed by livestock easily, and can typically be revegetated without issues of excessive erosion and <br /> slope stability. Geotechnical stability analysis is also generally not required if slopes of 3H:1 V or less are <br /> maintained during the mining and reclamation process. DRMS may approve steeper mining and reclamation <br /> configuration if sufficient geotechnical data are provided to demonstrate that the factors of safety as presented <br /> in MLRB Policy will be met, and that the resulting reclamation configuration will be stable. This is generally <br /> provided in the form of a geotechnical stability analysis performed and stamped by a registered engineer. A <br /> copy of the complete policies of the MLRB is available on the DRMS website. The relevant section "30.0- <br /> Factors of Safety for Slope Stability/Geotechnical Analysis"has been included as an attachment to this letter. <br /> For a final overall pit slope of no steeper than 3:1 the bench configuration should be a 30'wide bench with 10' <br /> high vertical faces or similar, or significant backfdling may be required to achieve acceptable final <br /> reclamation slopes. As previously stated, if the operator wishes to mine and reclaim to a steeper configuration <br /> (higher high-walls, thinner benches)a geotechnical evaluation of theproposed bench configuration should be <br /> provided to demonstrate that the proposed final benches will be result in a stable reclamation. <br /> (b) earthmoving; What is the total depth ofproposed mining? Please keep in mind that the pit will not be <br /> allowed to intercept groundwater during mining, or retain runoff at reclamation, (will need to be free draining) <br /> and that any final slopes will need to be reclaimed to be no steeper than 3H:1 V overall. (The current mining <br /> plan proposes much steeper final benched slopes, but provides no geotechnical study to show that the steeper <br /> proposed configuration will be stable in the long-term.) <br /> You will need to demonstrate that you will have sufficient backfrll available on-site to adequately <br /> backfrll/reclaim below grade excavations during mining. <br /> The information provided to-date states that an "estimated 200,000 cubic yards"of backfrll material and an <br /> estimated 16,133 cubic yards of topsoil maybe available for reclamation. This volume would need to be <br /> distributed as needed to backfrll and topsoil proposed bench surfaces as described in the reclamation plan, with <br /> the excess material available to backfrll and topsoil the pit as needed to prevent standing water and have <br /> internal slopes no steeper than 3H:1 V. These factors will likely determine what the total below grade <br />