2013-10-08_REVISION - C1982056 (22)

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incorporated in the RN-06 cost estimate. The information associated with Stipulation No. 64 has been incorporated into the PAP. Part A - Findings required by Section 2.07.6(2) 1. The permit application is accurate and complete. All requirements of the Act and the Regulations promulgated thereunder have been complied with (2.07.6(2)(a)). 2. Based on information contained in the permit application and other information available to the Division, the Division finds that surface coal mining and reclamation can be feasibly accomplished at the Foidel Creek Mine (2.07.6(2)(b)). 3. The assessment of the probable cumulative impacts of all anticipated coal mining in the general area on the hydrologic balance, as described in 2.05.6(3), has been made by the Division. This assessment entitled "Yampa River CHIA" (revised December, 2011) is available for inspection at the offices of the Division. A brief description of the Probable Hydrologic Consequences of the Foidel Creek Mine follows: Ground water Several possible effects to the ground water system have been identified. Dewatering and potentiometric drawdown in bedrock units Dewatering will occur in the Trout Creek Sandstone, Wadge Overburden, and Twentymile Sandstone. Monitoring data have verified both that this dewatering has occurred and the existence of a depression of the potentiometric surfaces of these hydrostratigraphic units in the vicinity of the mine. Diminution of bedrock discharge to alluvium and surface streams Gradient reversal due to mining could cause a decrease in natural discharge to alluvium and streams. This would persist for approximately 360 years until potentiometric levels recover to pre-mining conditions. Discharge of mine water discharge to the streams will more than offset this loss, which is estimated at approximately .02 cfs in Fish Creek. Degradation of Wadge overburden water Only the Wadge overburden aquifer is predicted to be degraded with regard to water quality. Estimates indicate that degraded water will persist for 23,000 years. Conductivity of degraded water is estimated at 4000-7000 umhos/cm. Areas immediately down gradient will be affected to a greater degree due to the close proximity to the source (mine workings). Due to dilution and dispersion, water quality will generally improve as the distance from the mine workings increases. Wadge overburden water is not presently used on the Twentymile Park basin. 17 Foidel Creek MineOctober 8, 2013