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Water Information Exhibit G <br />The pit from this operation lies to the north of the Colorado River. The pit will be flooded <br />once mining and reclamation has been completed. Controls for both surface and ground water <br />aze included in this plan. <br />Surface water exists in two forms in the permit azea during mining; being the Colorado River <br />and the sediment pond. The river runs in a westerly direction south of the permit area. A <br />minimum buffer of 100 feet will be maintained between the river and the pit. This buffer will <br />provide a sufficient safety factor against river capture. The second form of surface water will <br />be storm and process water dischazge. Substantial water will be discharged throughout the <br />mine's life. Pumping will occur continuously for the life of the mine. Water will be pumped <br />from dewatering trenches into the pond between the pit and the river. Sediment will be <br />allowed to settle in this pond prior to dischazge. A discharge permit has been submitted for <br />this discharge point. <br />Once all mining has been completed all pits will be allowed to fill. A gravel well permit and <br />substitute water supply plan will be filed concurrently with this application to account for the <br />water surface after mining has been completed and all depletions during mining. <br />As part of the substitute water supply plan a lined pond will be built on the upper terrace next <br />to the access road. This pond will be designed to store excess irrigation water during the <br />irrigation season to be used as augmentation water during the off season. Rather than being <br />pumped the bottom of the pond will be slightly above the fmal elevation of the lake surface. A <br />pipe and valve will be installed to allow draining of the pond without pumping. Please see the <br />augmentation pond details in Map C-4. Evaporative depletions from the water surface of the <br />augmentation pond has been accounted for in the substitute water supply plan as well. <br />Due to the close proximity of the pits to the Colorado River, the ground water table will be <br />very high. The expected water table depth lies from 5-10' below the surface. This height will <br />vary depending on the seasons. Wells servicing the Chambers' buildings lie within 600' of the <br />expansion. These wells maybe removed as part of the mining operation. A well release from <br />the wells has been included in the substitute water supply plan submission. <br />The following table shows the estimated amount and uses for water for the operation. Until <br />operations begin and all equipment is in use, actual consumption will not be known. <br />11(712005 Page Gl <br />