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6.4.4(c) <br /> The Phase 1 processing area will be gently sloped to the east to control surface stormwater flows. <br /> The processing area will be surfaced with compacted coarse aggregate, it is expected that all <br /> surface water that does not settle near the outlet culvert will percolate into underlying <br /> groundwater within 72 hours. <br /> As a new mining bench is opened, a safety and stormwater berm will be installed along the upper <br /> crest of the 50-foot-wide bench to collect and direct stormwater from above to dedicated <br /> drainage pathways maintained and transitioned throughout the site as mining progresses. In <br /> addition to controlling stormwater from the bench above in reclamation, the berm will serve to <br /> catch rock material from above as well as provide safety control for heavy mining equipment <br /> completing reclamation. Therefore, each benches' stormwater and safety berm will be <br /> constructed to a 1.5H:1 V slope to half wheel height of the largest piece of equipment on site as <br /> per MSHA regulations. Figure 3 shows these berms along the mining benches. <br /> 6.4.4(d) <br /> Blasting and mining will occur in 25-foot lifts, —50-foot-wide, along 500-foot lateral extents. <br /> The final blasts along the mining extent will be excavated and promptly backfilled to create a <br /> 2H:1 V slope. Therefore, the maximum active highwall during mining will be 25 feet tall and <br /> —500 feet long (Figure 3. Figure 4). See Rule 6.5 —Geotechnical Stability Exhibit. <br /> The elevation of each bench will dictate its lateral extents with higher elevation benches being <br /> smaller than lower elevation benches. In higher elevation initial mining areas, an entire bench <br /> may be mined at once while lower elevation benches may be mined in stages. Following higher <br /> elevation mining, lower elevation mining areas (which are inherently larger within a phase) will <br /> be developed in approximately 20-acre portions. It is anticipated that mining of phases may not <br /> explicitly occur in numerical order. Surficial gravel may be mined from Phase 3 "out-of- <br /> numerical-order" if the demand for alluvial gravel rises; Phases may also overlap one another <br /> temporally. Where possible, the overlying gravel will be mined by front-end loader into trucks <br /> for transport to the onsite crusher and screening plant. Additionally, Phase 4 mining may occur <br /> prior to Phase 3 mining. <br /> Young Ranch Resource <br /> February 2020 D-14 <br />