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^~ <br /> <br />CDOH&E, prior to discharge, the only thing the Division wants is to make <br />sure these structures will be adequate to handle the dewatering flows from <br />the pit. It is also to make sure if additional warranty will be needed to <br />remove these structures, or backfill them, whatever the chosen reclamation <br />plan is for the structures. <br />III) EXHIBIT "G WATER INFORMATION. <br />A) Operator estimates, the maximum annual consumptive water use from <br />mining at the site to be 89.40-acre feet/ year. Prior to any mining related <br />activity, the operator must obtain the water augmentation or substitute <br />water supply plan from the State Engineer and provide copy of the <br />approved water supply plan to DMG. <br />B) The operator provided a ground water model using the frame work 1) <br />variable aquifer properties and hydrologic stress 2) hydrologic influences <br />of the South Platt River and seepage from the ditches, creeks and ponds, <br />3) variable rechazges from precipitation and irrigation. For the Tucson <br />area, a recharge arte of 1.5 inches per year was selected based on RMC <br />report of 1991.4) Utilized a pump test conducted by Bishop and Brogden <br />and associates for a well that was approximately 30 feet deep in the clean <br />sand and gravel, to determine hydraulic conductivity, which was recorded <br />at 1770 feet per day at 565 GPM. Since that was in the clean sand and <br />gravel, for the model, utilized a hydraulic conductivity between 307 <br />feet/day to 762 feet/day, to determine probable hydrologic impacts due to <br />the proposed operation in the area. <br />C) Based on what the model predicted the operator must agree to the <br />following conditions: <br />1) Operator must reach an agreement or commit to the Division that <br />if any loss of water is detected in Brighton Ditch, during the <br />dewat~ ring of~Challenger pit~the operator will mitigate the loss <br />,to the ditch owners. Also an agreement with the ditch owners of <br />Braittner Ditch Company, even though the portion of the ditch <br />observed during the pre operational inspection is lined, there <br />could be some loss of water due to mining related activity. <br />2) Operator must agree to mitigate the probable impacts predicted <br />to the greenhouse prior to any dewatering taking place. <br />3) All probable mounding ofwaters predicted in the model must be <br />included in the substitute water supply plan, even though <br />possible mounding only occurred only when the simulation was <br />run for the Tucson South cell aze only. <br />4) Establish baseline water levels in all wells with in 600 feet of the <br />permit or affected azea at least once prior to mining. <br />5) Monitor monthly all monitoring wells until mining begins and <br />quarterly after mining begins and until recalamtion is completed <br />and the site is released from recalamtion responsibilities. The <br />quarterly report to be submitted to DMG on semi annual basis. <br />