2020-02-07_PERMIT FILE - M2020007 (2)

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EXHIBIT G WATER INFORMATION (CONT) significantly through seasons and years, depending on many influences, including, climate, precipitation, irrigation, other pumping rights, and much more . L.G. Everist, Ines . experience on other mines in the South Platte River valley indicates that groundwater levels can fluctuate as much as 7+ feet depending on the season. In a normal mitigation trigger plan, the trigger limits would be set at 3 foot change plus or minus change over a 3-month average. Realistically, in this case the trigger number should be based on a 3-foot change determined by a line that approximates a up or downward trend of the water table and considers outside impacts such as, drought, adjoining mining activities, storm events or decreased irrigation activities . At the current time, there is no mounding mitigation plan for when the water table increases . We do not expect this to be a problem where the slurry walls are in close proximity to a flowing water body like the ditches, return flow ditch and the South Platte River. Mounding would be controlled by those water surfaces and it would only affect Cannon Land Company areas around the reservoirs . On the east side of the Evans #2/Platte Valley Canal, the ground-water table averages 11 feet deep and there are enough unlined areas crossing thru the lined reservoirs to allow for some increase without impacting surface features . In the eastern area groundwater averages 12 feet below the surface, there are numerous, gaslines and road corridors that would allow ground water to bypass the lined areas . The mining operation will have minimal effect on the South Platte River in the form of minor groundwater depletions due to evaporation and water uses associated with mining. The depletions to the South Platte will be mitigated thru a temporary Substitute Water Supply Plan (as required and approved by the Division of Water Resources) to prevent injury to the vested senior water rights . The reclamation plan proposes the creation of 8 (or fewer) slurry wall lined reservoirs that will not be hydraulically connected to the South Platte River or any alluvial aquifer. The Mining Plan includes four (4) unlined pits that will be backfilled with excess overburden and wash fines from the sand and gravel processing plant . The reservoir phases will be sealed prior to mining, thereby eliminating the groundwater draw down which is typically associated with mine site dewatering. This will also eliminate or minimize the possibility of any adverse impacts to nearby alluvial wells . Potential Water Resource Impacts Ground Water Wells We expect this mining operation will have no or minimal impacts on the prevailing hydrologic balance . Sand and gravel mining related impacts to groundwater wells near the pit will be mitigated through the installation of slurry walls around the perimeter of new L.G. Evenst, Inc. Ragsdale Reservoirs 28 February 6, 2020