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interbedded nature of the formations, consideration of each formation as a <br />hydrologic unit is reasonable. <br />A fourth hydrologic unit is the alluvium of the White River and its tribu-. <br />taries. The maximum thickness of the White River alluvium was found to be 37 <br />feet. <br />Hydrology <br />No major usage of ground water has been defined by the applicant. Due to the <br />generally low specific yields of aquifers in the region, 0.2 to 2.0 percent, <br />and poor ground water quality, it would not be expected that ground water usage <br />would be high. Of the water rights that do exist within 70 square miles encom- <br />passing the lease area, all are surface water rights. The water-bearing pro- <br />perties of nearly all of the bedrock in the mine plan area and are largely <br />dependent on secondary porosity. Recharge of the bedrock aquifers occurs prim- <br />arily at higher elevations north of the permit area through infiltration of <br />precipitation in outcrop areas. Discharge is by small seeps along hill sides <br />where aquifers are exposed by the White River, and in the past to a very minor <br />extent, by pumping of wells. The discharge of the ground water in the Iles <br />Formation has not been identifiAd; however, this deeper aquifer should not be <br />impacted by the proposed mining operation due to the thickness of the confining <br />layers, approximately 30 feet. <br />The alluvial aquifer contains gravel, sand, silt and clay sized material which <br />causes the alluvium to be much less permeable than would normally be expected. <br />Within the White River, the alluvium has a maximum depth of '37 feet and water <br />occurs in an unconfined condition. Within the alluvial aquifers, recharge is <br />from precipitation and bedrock aquifer discharge and discharge is to the stream <br />or river, use of water by greasewood and salt ceder growing in the stream <br />basins, and in the past to a very minor extent, pumping of wells. <br />The movement of ground water is affected by the Red Wash Syncline and major <br />fracture zones along faults located along the Red Wash, Scullion Gulch, and the <br />White River. Ground water in the northwest part of the mine plan area moves <br />2 <br />