2009-03-02_REVISION - M2004009 (12)

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6.4.4 Exhibit D - Mining Plan begin in Cell 6. Overburden from Cell 6 will be stripped and placed in Cell 5 and as concurrent backfill in Cell 6. See Exhibit C-2 Mine Plan Map, Sheet 1. Cell 6 The portion of Cell 6 that occurs in the area of the existing stream that flows from the west side of Cell 6 to the Plumb and Dailey Ditch will be mined and backfilled (see Exhibit E, Reclamation Plan, Cell 6) during the non-irrigation season when there is little flow in the stream and the stream does not contribute to flows in the ditch. The stream flows will be diverted into a 36 in. CMP which will be placed into the backfilled portion of Cell 6, as shown on Exhibit F Reclamation Plan, Sheet 2. This design was approved as part of the original permit for this site, as with the low-water crossing. Overburden from Cell 6 will be stripped and placed in Cell 3 and as concurrent backfill in Cell 6. All mining areas west of Boulder Creek will backfilled to grade, leaving no exposed groundwater or clay-lined ponds. Water Diversions and Impoundments Dewatering trenches will be dug at the toes of the pit slopes to facilitate dry mining. Water will be allowed to gravity feed to the west or east of the active mining areas where it will be pumped from a dug sump to Boulder Creek. According to an agreement with the ditch company or approval by the CDRMS, a hydraulic barrier trench will be dug on both sides of the Plumb and Dailey Ditch, and lined with impermeable synthetic material. The hydraulic barrier will hydraulically isolate the Plumb & Dailey Ditch from the local water table and prevent the dewatering operation from affecting ditch flow. Letters discussing a ditch agreement with the Plumb and Dailey Ditch Co. should be contained in the permit file and as part of AM-1 in 2006. At this time, no land disturbing activities will occur near the ditch until an agreement can be worked-out with the ditch company or approval by DRMS. There is a possibility that the entire portion of land under this permit west of Boulder Cr. may not be mined at all. Size of Area to Be Worked at One Time Concurrent reclamation will minimize the area requiring reclamation at any one time. The largest area of un-reclaimed pit area to occur at any one time would exist around year 4, when Cell 2 is nearly half-mined (-34 acres). At this point, approximately 7,500 linear feet of pit wall mined at 0.5:1 would occur. Typically, the largest area to be worked at one time will be less than 35 acres The largest overburden stockpile that will occur at one time will be no more than approximately 150, 000 yd3