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The maximum exposed surface area at the site during mining is estimated at 0.75 acres. Ogilvy <br /> River Farm, LLC plans to keep the site dewatered throughout the life of 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) (1967-2023) was used. The long-term average precipitation at the Ogilvy <br /> River Farm Pit mining site is estimated at 14.26 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 35.02 inches or 2.92 <br /> feet. <br /> The maximum annual evaporative loss from the 0.75 acres is 2.19 ac-ft. <br /> Operational Loss <br /> The average annual production from the Ogilvy River Farm Pit mining site is estimated at <br /> 650,000 tons. Using 4% moisture content, (2% for moisture in the product and 2% for water <br /> used to wash), the total associated consumptive use for water retained in the material mined <br /> and water used for washing is 19.1 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 26.5 ac-ft. <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 28.69 ac-ft. <br /> Replacement Water <br /> The replacement of consumptive uses at the site 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 1 Well Permits in the Ogilvy River Farm 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 /> Between the sources, all permitted and decreed wells are included. Table G-1 below is a <br /> corresponding list of wells as numbered in the Ogilvy River Farm Pit— Groundwater Evaluation <br /> by McGrane Engineering, LLC that is attached that are within 600 or more feet of the mining <br /> limits that were within the 1 to 3 foot mounding area on the north and east side of the pit. <br /> .n IN Clyde <br /> JoT Consulting,Inc. Bernhardt Sand and Grra el Pit <br /> �' DRMS 112 Permit Application <br />