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It is estimated that sand and gravel underlying the overburden is between 28' to 30' thick. The underlying bedrock is composed of a shale and claystone formation that extends to greater depths. Water Consumptive Use Water use at the Riverbend Operation will include evaporation from exposed groundwater, water used for washing sand and gravel, and water pumped for dust control of haul roads and stockpiles, and water used in the ba[ching of concrete. The mining operation will intercept the alluvial aquifer that supplies water to the South Platte River. The evaporative losses at the site will consist of the exposed water within the dewa[ering trench, the collection area, and in the 2.0 acre wash pond. Approximately 0.5 acre of water will be exposed in the dewatering trench and collection area. Total exposed surface area will be approximately 2.5 acres and will result in a net annual evaporation of 7.4 acre-ft. There will be excavation and stockpiling of mined material on-site. The water contained in the material when mined is considered a consumptive use. The operator anticipates that 800,000 tons of material will be mined and washed from the area annually. The moisture in the aggregate would create a depletion of 17.7 acre-fee[ per yeaz. In addition, 6.1 acre-feet will be used at the concrete batch plant. The operation will also use 1.0 acre-foot of water in the production of asphalt. Water will also be applied to haul roads and stockpiles for dust control from a 2,000 gallon capacity water truck three days a week during the year. This results in a consumptive use of 1.5 acre-feet per yeaz. The total annual consumptive use associated with the mining operation is 33.7 acre-feet. All uses are summarized as follows: Evaporation 7.4 acre-fee[ Water Used in Concrete Production 6.1 acre-feet Water Used in Asphalt Production 1.0 acre-feet Moisture Retained in Product 17.7 acre-feet Dust Control 1.5 acre-feet Total 33.7 acre-feet G-2