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a one-foot drawdown in the Wadge Overburden was predicted to be 401 feet in the Grassy Creek drainage and 564 feet in the Sage Creek drainage. The one-foot drawdown radius in the Wadge Coal was predicted to be 369 feet in the Grassy Creek drainage and 468 feet in the Sage Creek drainage. Radial distances to the one-foot drawdowns in the Wolf Creek Overburden and Wolf Creek Coal in the Sage Creek drainage were predicted to be 452 and 491 feet, respectively. Because the drawdowns due to pit inflows will be mostly contained within the leasehold area, and adjacent water users aze located beyond the one-foot drawdown contours, no significant impact on groundwater use due to pit inflows is predicted. Impacts of Production Well Seneca Coal Company predicted that maximum drawdowns in the Trout Creek aquifer resulting from nine years of pumping in the Yoast Production Well would be 186 feet. After 20 yeazs of recovery, the residual drawdown within one mile of the well is predicted to be less than two feet. The radial distance to the one-foot drawdown contour afrer 20 yeazs of pumping was predicted to be 10 miles. The only known Trout Creek wells within this radius are associated with the Twentymile Coal Mine and are between seven and ten mile from the proposed Yoast Mine well. The drawdown at this distance from the Yoast Mine well should not significantly impact these wells. Streamflow depletions in the Yampa River, Fish Creek, Middle Creek and Trout Creek channels due to changes in the groundwater regime were all predicted to be less than 0.55 acre-feet per yeaz. However, streamflow depletions in Sage Creek and Grassy Creek were predicted io be higher: 4.9 acre-feet per year in Sage Creek and 5.8 acre-feet per year in Grassy Creek. Impact of Replaced Spoil on Groundwater Seneca Coal Company predicted that the replaced spoil would have a 25% higher hydraulic conductivity than the undisturbed material. Other than that, the primary effect on groundwater would be degradation of quality with respect to total dissolved solids (TDS). Seneca Coal Company predicted that the increase in TDS concentrations in the bedrock aquifers will range from 70% in the Wadge Overburden to over 300% in the Wadge Coal. These predictions are for groundwater in close proximity to the resaturated spoil, within the permit azea. As groundwater migrates away from the resaturated spoil, mixing, dilution from unaffected recharge, and geochemical changes will decrease the TDS concentrations. Well yields in these bedrock units, the Wadge Coal and Overburden and the Wolf Creek Coal and Overburden, aze insufficient for irrigation purposes. Yoast Mine 26 August 3, 2005