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6.4.4 Exhibit D -Mining Plan <br />1) Begin excavation of a trench approximately 4 ft wide on the northeast <br />portion of the ditch (lowest point) as shown in Exhibit C-2, Mine Plan Map <br />Sheet 1 and work to the south. <br />2) During excavation of the trench, begin dewatering as soon as water is <br />intercepted. Excavate a low point for water to drain and keep the <br />excavation drained. <br />3) Excavate all sand and gravel into haul trucks and haul to processing. This <br />will insure backfill does not get mixed with coarse gravel. <br />4) Place 40 mil PVC plastic liner into bottom of trench as shown in the <br />hydraulic barrier detail to create an anchor by wrapping around the ditch <br />side of the keyway approximately 2 ft X 2ft X2ft. Backfill keyway on both <br />sides of anchor with native overburden (ML-CL). Do not backfill with <br />coarse materials. <br />5) Backfill both sides of the PVC liner equally as backfilling proceeds upward <br />Following construction of the hydraulic barrier trench, overburden will be stripped <br />from Cell 3 and stockpiled in Cell 6. As gravel extraction progresses, concurrent <br />backfilling adjacent to oil and gas structures will occur no later than two weeks <br />following excavation - as indicated in Exhibit C-2 -Mining Plan Map. <br />Cell 4 <br />To enable recharge of mine dewatering water to the alluvial aquifer, Cells 5 and 6 <br />will be mined prior to Cell 4, as the recharge trench for Cells 5 and 6 will be <br />located within the boundaries of the proposed Cell 4. Following mining of Cell 6, <br />Cell 4 will be mined. <br />Overburden will be stripped from Cell 4 and backfilled into Cell 3. Enough <br />overburden will be left behind to backfill adjacent to oil and gas structures. As <br />gravel extraction progresses, concurrent backfilling adjacent to oil and gas <br />structures will occur no later that two weeks following excavation - as indicated <br />in Exhibit C-2 -Mining Plan Map. <br />Cell 5 <br />Prior to mining Cell 5 or 6, construction the Hydraulic Barrier trench on the west <br />side of the Plumb and Dailey Ditch will be completed as shown in and as <br />described in "Cell 3 Hydraulic Barrier Trench Construction." Additionally, the <br />recharge trench will be constructing in future Cell 4 to receive pit dewatering <br />water from Cells 5 and 6. Overburden from Cell 5 will be stripped and placed in <br />Cell 6. Following mining of Cell 5, stripping will begin in Cell 6. <br />Cell 6 <br />The portion of Cell 6 that occurs in the area of the existing stream that flows from <br />the west side of Cell 6 to the Plumb and Dailey Ditch will be mined and backfilled <br />(see Exhibit E, Reclamation Plan, Cell 6) during the non-irrigation season. Prior <br />to mining Cells 5 or 6, construction the Hydraulic Barrier trench on the west side <br />Turnpike Mining Resource M-2004-AM-1 <br />Regular 112 application <br />