Laserfiche WebLink
topsoil 1.0 feet <br />overburden 4.2 feet <br />gravel 15.5 feet <br />TOTAL 20.7 feet <br />Once groundwater is encountered approximately 5-10 feet below the existing surface elevation of <br />4494', a pump will be set in the git with a gravel berm filter to dewater the mining excavation. Dur- <br />ing the first month of pumping, flow rates aze expected to be 3000 to 4000 gaUminute and then drop <br />off to 1000 gal/minute thereafter. The water will be pumped into the old gravel pond located south- <br />west of the permit on the Rigg property. All discharges will be regulated by the NPDES permit <br />which United will have for the site. The pump will utilize a small generator for power. <br />The mining will be done by dozers, front end loaders and/or excavators. The mine slopes will be <br />1.OH:1.OV, which will later be backfilled with overburden and topsoil to 3H:1V. Trucks of 24 ton <br />capacity will be loaded directly in the pit and will leave the site though the northeast or southeast <br />access roads to 19 Road. All gravel trucks will be covered and will deliver the raw gravel to <br />United's main River Road facility on the west side of Grand Junction. There will be no processing, <br />crushing, screening or any other facilities on site. All equipment will be fueled by fuel truck, there- <br />fore, there will be no fuel storage on site. There will be no truck scale, trailers, or other structures. <br />The Phase 1 area of 3.2 acres is expected to be mined out during the winter of 2002-2003. It is ex- <br />pected that 110,000 tons will be mined and moved to the River Road facility during this time. <br />Once the Phase 1 area has been mined out, the extra overburden stored on the Phase 2 area will be <br />moved into the pit to backfill all slopes to 3H:1V except for the slope adjacent to Phase 2, which <br />will be excavated the following year. It is possible that 4000 cy of the 17780 cy will remain in the <br />stockpile during the winter. All equipment will be moved off site and the pump will be removed, <br />allowing the lake to fill to the alluvial groundwater level, approximately 6-10 feet lower than the <br />surrounding ground elevation. <br />The operation will resume in the late fall of 2003, when the pump will be te-installed to dewater the <br />pit. Once this is done, the mobile equipment will move the 4000 cy of overburden previously stock- <br />piled on the Phase 2 area to the Phase 1 area pit bottom. Once this is done, the equipment will strip <br />19 Road Pit 10!02 10 <br />