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ARR-5 rl <br /> the event incremental resource is present and recoverable within design limitations, and market <br /> conditions warrant doing so. <br /> Please commit to submitting and receiving approval from the Division for a technical revision <br /> pursuant to Rule 1.9 to revise the maximum main pit area and fines recovery pit depth prior to <br /> excavating deeper than the currently projected 25 feet below the existing ground surface. <br /> CSC Response <br /> In order to clarify specific details referenced in the Division's comment, and stipulate to the <br /> requested commitment(s),CSC provides the following: <br /> • The fines recovery pit will be excavated to its full(maximum depth),which is to be nominally <br /> 25 ft. below existing ground surface,i.e.,resulting in an approximate invert elevation of 4,880 <br /> ft. above mean seal level (amsl), prior to commencement of processing operations. The fines <br /> recovery pit will be subsequently filled with process fines. Thus, it is not envisioned that the <br /> fines recovery pit would be"deepened". <br /> If incremental capacity were to be required, such would likely be accomplished through <br /> increasing (raising) the elevation of perimeter containment (i.e., above existing ground <br /> surface). However, this is not anticipated in the "base case" mine plan; and, may or may not <br /> be required even if CSC were to seek authorization (through Technical Revision) for <br /> incremental fines storage,given that the"base case"design incorporates an anticipated surplus <br /> volume. <br /> Nevertheless, CSC acknowledges that any increase in fines recovery pit storage capacity <br /> (above that expressed in the Application) would require a Technical Revision to the permit; <br /> and therefore commits to submitting and receiving approval from the Division for any such <br /> Technical Revision. <br /> • Existing surface topography elevations within the prescribed pit envelope (refer to Exhibit E- <br /> 2: Reclamation Plan)range from a high of approximately 4,910 ft.above mean sea level(amsl) <br /> along the south-central edge of the pit, to a low of approximately 4,905 ft. amsl near the <br /> northeast corner of the pit. Thus, there is a variance in the existing ground elevation of <br /> approximately 5 ft. across the planned pit area prior to commencement of mining. <br /> CSC indicated (on Page C-12 of the Application) a projected nominal mining depth of 25 ft. <br /> below existing ground surface on the basis of utilizing the predominant lower surface <br /> elevation(s). In order to accommodate a known variance in existing pre-mining surface <br /> elevation(s) across the pit in entirety,CSC then employed(on Page C-15)the phraseology"25 <br /> ft. to 30 ft."to incorporate all areas of the pit. As depicted in Exhibit E-2: Mine Reclamation <br /> Plan, the projected end-of-life (mined) pit floor elevation is anticipated to be approximately <br /> 4,880 ft. amsl. Accordingly, mining occurring in the lower (4,905 ft.) elevation zones would <br /> extend to a depth of approximately 25 ft.in order to terminate at the pit floor elevation of 4,880 <br />