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Evaporative Loss <br /> Evaporative losses are dependent on the exposed water surface area, which may shift <br /> throughout the mining operation, but will not exceed the maximum. Exposed surface area at the <br /> Sunset Industrial Pit mining site will include groundwater exposed in the dewatering trenches <br /> and recharge pond. The maximum exposed surface area at the site during mining is estimated <br /> at 3.83 acres. J-2 Contracting Company plans to keep the site dewatered throughout the life of <br /> the mine. <br /> Evaporation data was taken from NOAA Technical Report NWS 33, Evaporation Atlas for the 48 <br /> Contiguous United States. The annual gross evaporation was determined to be 45 inches for <br /> this location. Monthly evaporation percentages are established by guidelines set by the State <br /> Engineer's Office. To determine precipitation, data from the National Weather Service for <br /> Greeley, CO (UNC) (1967-2022) was used. The long-term average precipitation at the Sunset <br /> Industrial Pit mining site is estimated at 14.69 inches. Effective precipitation is calculated as <br /> 70% of the total precipitation. The net evaporation is the difference between gross annual <br /> evaporation and effective precipitation. The resulting net evaporation is 2.52 feet. <br /> The maximum evaporative loss from the 3.83 acres is 9.67 ac-ft. <br /> Operational Loss <br /> The average annual production from the Sunset Industrial Pit mining site is estimated at <br /> 650,000 tons. Using 4% moisture content, the total associated consumptive use for water <br /> retained in the material mined is 19.95 ac-ft. <br /> Dust control use is 10,000 gal/day, 6 days/week, 4 weeks/month for 10 months of the year. This <br /> equates to 7.4 ac-ft. <br /> Maximum annual operational loss is estimated to be 27.35 ac-ft for Phase 1. <br /> Consumptive Use <br /> The maximum annual consumptive use (operational loss + evaporation loss) at this site during <br /> the mining operation is estimated to be 37.02 ac-ft for Phase 1. <br /> Replacement Water <br /> The replacement of consumptive uses at the site is will be accounted for in a substitute water <br /> supply plan (SWSP) approved by the State Engineer. The SWSP will be obtained prior to any <br /> mining activities occurring that expose groundwater. <br /> Surrounding Water Rights <br /> The attached Figure A-1 Well Permits in the Sunset Industrial Pit— Groundwater Evaluation by <br /> McGrane Engineering, LLC shows the permitted wells within 600 feet of the mining limits and <br /> permitted wells within the boundaries of the groundwater model/evaluation. The well information <br /> and locations were obtained from the Division of Water Resources online mapping well permit <br /> locator. This well and water rights information was cross checked with the State's CDSS. <br /> •' J&T Consulting,Inc.Inc J-2 Contracting Company <br /> Sunset Industrial Pit <br /> DRMS 112 Permit Application <br />