2019-05-24_PERMIT FILE - M2019028 (11)

Home Browse Search

Evaporative Loss Evaporative losses are dependent on the exposed water surface area, which may shift throughout the mining operation, but will not exceed the maximum. Exposed surface area at the DPG Mining site will include groundwater exposed in the dewatering trenches and discharge settling pond. The maximum exposed surface area at the site during mining is estimated at 0.38 acres. J-2 Contracting Company plans to keep the site dewatered throughout the life of the mine. Evaporation data was taken from NOAA Technical Report NWS 33, Evaporation Atlas for the 48 Contiguous United States. The annual gross evaporation was determined to be 45 inches for this location. Monthly evaporation percentages are established by guidelines set by the State Engineer's Office. To determine precipitation, data from the National Weather Service for Greeley, CO (053553) (1967-2019) was used. The long-term average precipitation at the DPG Mining site is estimated at 14.20 inches. Effective precipitation is calculated as 70% of the total precipitation. The net evaporation is the difference between gross annual evaporation and effective precipitation. The resulting net evaporation is 2.92 feet. The maximum evaporative loss from the 8.76 acres is 25.58 ac-ft. Operational Loss The average annual production from the DPG Mining site is estimated at 750,000 tons. Using 4% moisture content, the total associated consumptive use for water retained in the material mined is 22.07 ac-ft. Dust control use is 10,000 gal/day, 6 days/week, 4 weeks/month for 10 months of the year. This equates to 7.4 ac-ft. Maximum annual operational loss is estimated to be 29.47 ac-ft for Phase 1. Consumptive Use The maximum annual consumptive use at this site during the mining operation is estimated to be 55.05 ac-ft for Phase 1. Replacement Water The replacement of consumptive uses at the site is will be accounted for in a substitute water supply plan (SWSP) approved by the State Engineer. The SWSP will be obtained prior to any mining activities occurring that expose groundwater. Surrounding Water Rights The attached Figure G-1 shows the permitted wells within 600 feet of the mining limits. The well information and locations were obtained from the Division of Water Resources online mapping well permit locator. This well and water rights information was cross checked with the State's CDSS. Between the sources, all permitted and decreed wells are included. Table G-1 below is a corresponding list of wells as numbered in Figure G-1. � JET Consulting,inc. Journey Ventures,LLC' Journey Ventures Pit DRMS 112 Permit Application