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6.2 Process Water <br />A dry crushing process will be used for the mined aggregate and <br />therefore no water will be used for this process. The only <br />consumptive use of water for the mining operation, other than <br />evaporation will be water retained in the material excavated from <br />the site and water pumped from the pit which will be used for dust <br />control. <br />Aggregate which has been stockpiled for a <br />considered to contain 48 water by weight. <br />appropriate water content for pit run aggrega <br />water content in the annual production rate <br />aggregate equals approximately 5.89 acre-feet <br />use. <br />Approximately 3/8 inch of water will <br />(2900 linear feet of Weld CR 24 1/2 <br />feet at plant) of roads to control <br />required approximately 60 days each <br />consumptive use for dust control is <br />6.3 Sveporative Losaes <br />week is generally <br />This would be an <br />te. Calculations of <br />of 200,000 tons of <br />(af) of consumptive <br />be applied a day to 2.5 acres <br />and a maximum of 2000 linear <br />dust. Dust control will be <br />year. Therefore the annual <br />estimated at 6.2 acre-feet. <br />The NOAA Technical Report NWS 33, 'Evaporation Atlas for the <br />Contiguous 48 United States', published by the U.S Department of <br />Commerce was used to determine the amount of evaporation. The <br />annual evaporation is 39 inches at the subject location. <br />Lake freezing is expected to occur in the months of January and <br />February and consequently the annual net evaporation is reduced by <br />6.1 percent. The net annual evaporation from a lake surface at the <br />site is 3.05 ft (36.6 inches). <br />Due to high water table conditions at the site groundwater <br />consumptive use has occurred historically. A consumptive use <br />credit is therefore applied to the net evaporation reducing the net <br />evaporation by 12 inches annually. Hence the net consumptive use <br />due to exposure of groundwater is 2.05 ft or 24.6 inches <br />During the final phase of mining, phase IV, the other lakes will be <br />filled with groundwater. The annual consumptive use during this <br />final phase of mining will be as follows: <br />Evaporation from Phase I, II, Iii Lakes: 98.8 acre-feet <br />(48.21 surface acres) <br />Water retained in excavated material: 5.9 acre-feet <br />Dust Control water: 6.2 acre-feet <br />Total 110.9 acre-feet <br />