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~' <br />EMPIRE PIT <br /> <br />Exhibit D <br />Mining Plan <br />The Empire Pit has been mined continuously since 1935. At this time the <br />future mining plan consists of a continuation of that long term operation in <br />too phases as noted on the accompanying "Extraction Plan Map". The method <br />of mining consists of open pit using draglines, loaders, and trucks. <br />At present, water is removed from the Phase I mining area for the gravel <br />crushing and washing operations, then impounded in a series of lagoons, <br />located on the east (downstream) end of the property. I~later is discharged <br />from these lagoons through percolation and evaporation. The percolated <br />water returns to the Clear Creek aquifer through the underlying gravel <br />strata. This system will be continued until the Phase I area noted on the <br />"Extraction Plan" is mined. Phase II will have gravel extracted to a depth <br />above the natural water table, with no permanent ponds being retained, with <br />the goal of returning the Phase II area to pasture. <br />The accompanying "Extraction Plan" denotes the two basic areas to be mined, <br />the acreage of each area, and the estimated range of time each Phase will <br />be operated. Also noted on that plan is the area which can be classified <br />as moderate disturbance, located between the Phase I and Phase II areas. <br />The nature of the deposit to be mined is sand and gravel. Thickness of the <br />deposit is an average 50 feet, under almost no over-burden material. The <br />material immediately below the oravel deposit consists of a pre-Cambrian <br />gneiss or schist metamorphic rock known as the "Idaho Springs" formation. <br />Although not planned at the Empire Pit, this formation has reportedly been <br />mined in this vicinity for crushed rock sub-base material. <br />