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wells south of the site and one well west of the site. If pumping,groundwater will be drawn <br /> to these wells. <br /> Potential Slurry Wall and Mining Impacts to Local Groundwater Levels <br /> For all lined cells, a properly constructed slurry wall will tend to isolate these cells from the surrounding <br /> alluvial groundwater table. The liner around these cells could cause"mounding"of groundwater(increase in <br /> groundwater elevation) on the upgradient side (southeast) of the lined cells and a potential "shadow effect" <br /> (reduction in groundwater level) on the downgradient side (northwest) of the mine. Because the liner will <br /> tend to isolate these cells from the surrounding groundwater table, the effects of dewatering when mining <br /> lined cells will tend to not extend beyond the liner. <br /> Any mounding effect on the upgradient side of the site (south and southwest) is anticipated to be on the <br /> order of a few feet or less and will dissipate with distance from the mine. Similarly, shadowing effects will be <br /> on the order of a few feet and will dissipate with distance from the mine. The shadowing effects will be <br /> minimized by the presence of the South Platte River to the northwest and the Western Mutual Ditch that <br /> runs between Cells 5A and 5B and the Farmers Independent Ditch which runs southeast of the site. <br /> Dewatering of the unlined cells (Cells 1 and 2) will result in decreases in water levels around these cells. <br /> Since there are no wells permitted within 600' of the unlined cells, the effects of dewatering the unlined cells <br /> will be minimal. <br /> Area Wells <br /> A review of the permitted wells on file with the State Engineer's Office (SEO), Division of Water Resources <br /> (DWR) indicates that there are nineteen permitted pumping wells within 600 feet of the permit boundary. All <br /> of these wells are screened in the alluvium. None of these wells are within 600 feet of the unlined cells <br /> (Cells 1 and 2). The well locations and applicants are shown on Figure G-2 attached at the end of this <br /> section. <br /> Groundwater Level Monitoring and Mitigation Plan <br /> Dewatering during mining of Cells 1 and 2 is unlikely to affect any wells in the area. However, if the miner <br /> receives a complaint,the following mitigation plan will be implemented. <br /> The site monitoring wells will be measured monthly to identify potential changes in alluvial groundwater flow <br /> or elevation associated with mining and reclamation activities. Baseline data will be collected prior to <br /> dewatering or construction of the slurry walls. Baseline data will be collected from the monitoring program <br /> will provide a range of relative water levels associated with pre-mining groundwater conditions. Experience <br /> at other mines in similar geologic settings has found that groundwater levels tend to fluctuate being highest <br /> in the summer irrigation season and lowest in the winter and early spring. The monthly measurements will <br /> be tabulated and included with the DRMS annual report for the site. <br /> If, during mining or reclamation, the relative seasonal groundwater elevation at any monitoring wells differs <br /> from baseline conditions by more than 2 feet, and the condition was not observed during baseline <br /> Red Tierra Equities, LLC—Section 20 Mine—MLRB 112 Permit Application <br /> Exhibit G-4 <br />