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1. The permit application is accurate and complete. All requirements of the Act and the <br /> Regulations promulgated thereunder have been complied with(2.07.6(2)(a)). <br /> 2. Based on information contained in the permit application and other information available to <br /> the Division, the Division finds that surface coal mining and reclamation can be feasibly <br /> accomplished at the Foidel Creek Mine (2.07.6(2)(b)). <br /> 3. The assessment of the probable cumulative impacts of all anticipated coal mining in the <br /> general area on the hydrologic balance, as described in 2.05.6(3), has been made by the <br /> Division. This assessment entitled "Impact on Yampa River CHIA" (revised August, 2015) <br /> is available for inspection at the offices of the Division. <br /> A brief description of the Probable Hydrologic Consequences of the Foidel Creek Mine <br /> follows: <br /> Ground water <br /> Several possible effects to the ground water system have been identified. <br /> Dewatering and potentiometric drawdown in bedrock units <br /> Dewatering will occur in the Trout Creek Sandstone, Wadge Overburden, and Twentymile <br /> Sandstone. Monitoring data have verified both that this dewatering has occurred and the <br /> existence of a depression of the potentiometric surfaces of these hydrostratigraphic units in <br /> the vicinity of the mine. <br /> Diminution of bedrock discharge to alluvium and surface streams <br /> Gradient reversal due to mining could cause a decrease in natural discharge to alluvium and <br /> streams. This would persist for approximately 360 years until potentiometric levels recover <br /> to pre-mining conditions. Discharge of mine water discharge to the streams will more than <br /> offset this loss, which is estimated at approximately .02 cfs in Fish Creek. <br /> Degradation of Wadge overburden water <br /> Only the Wadge overburden aquifer is predicted to be degraded with regard to water quality. <br /> Estimates indicate that degraded water will persist for 23,000 years. Conductivity of <br /> degraded water is estimated at 4000-7000 umhos/cm. Areas immediately down gradient will <br /> be affected to a greater degree due to the close proximity to the source (mine workings). <br /> Due to dilution and dispersion, water quality will generally improve as the distance from the <br /> mine workings increases. Wadge overburden water is not presently used on the Twentymile <br /> Park basin. <br /> Degradation of alluvial water quality in Fish Creek <br /> Water will move down gradient to the natural discharge points along Fish Creek. Alluvial <br /> aquifers are recharged mainly by stream flows during high flow conditions and to a lesser <br /> Foidel Creek Mine 17 August 4,2023 <br />