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Detention of surface water runoff in sedimentation ponds and related evaporation loss <br />Treatment of disturbed area runoff will cause a decrease in peak Flows in the Fish Creek and Foidel Creek <br />watersheds. However, any decrease due to retention in sedimentation ponds will be more than offset by <br />increased water downstream due [o mine water discharge from the underground workings. Increased <br />levels of suspended solids will be minimized due to sedimentation ponds and NPDES effluent limitations <br />established for each point-source discharge from the mining operation. <br />Diversion of overland Flow with ditches <br />Diversions will deprive small areas of water but will not significantly reduce Flows downstream. <br />Induced recharge or discharge by underground mine dewaterin¢ <br />Mine dewatering can cause changes in the natural process of stresm discharge and recharge. Mine <br />dewatering and gradient reversal may cause small decreases in Fish Creek and Foidel Creek stream flows <br />in and around the mined area. Increased or modified recharge is also possible due to subsidence. Due to <br />the small areal extent and the shale aquitards between the Wadge coal and the streams, increased recharge <br />would likely not be significant. <br />Subsidence impacts on Foidel and Middle Creeks <br />Subsidence of portions of Foidel Creek and Middle Creek will cause gradient changes in the streams. <br />These gradient changes will result in ponding and channel incision controlled by the streams relationship <br />to orientation of the Iongwal] panels and gateroads. Subsidence cracks in the near surface also have the <br />potential to disrupt the streamflow. Based on the presence offine-grained alluvial material, any disruption <br />of stream flows would be temporary. Site-specific experience from Foidel Creek resulted in a complete <br />loss of streamflow for approximately 24 hours followed by a recovery over the subsequent two months. <br />See Section B, part IIIB of this document for more information concerning the surface and ground water <br />monitoring plan. <br />The Division has evaluated each of these impacts and finds that the operations proposed under the <br />application have been designed to prevent damage to the hydrologic balance outside the proposed permit <br />azea (2.07.6(2xc)). <br />4. The Division finds that the affected area is, subject to valid rights existing as of August 3, 1977, not <br />within: <br />a) An area designated unsuitable for surface coal mining operations (2.07.6(2)(d)(i)); <br />b) An area under study for designation as unsuitable for surface coal mining operations <br />(2.07.6(2)(d)(i7); <br />c) The boundaries of the National Park System, the National Wildlife Refuge System, the National <br />System of Trails, the National Wilderness Preservation System, the Wild and Scenic Rivers System <br />including rivers under study for designation, and National Recreation Areas (2.07.6(2)(d)(iii)(A)); <br />d) Three hundred feet of any public building, school, church, community or institutional building, or <br />public park (2.07.6(2)(d)(iii)(B)); <br />C:\JHB\C82056\RN03\RN03FI N D.doc <br />16 <br />