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• 24-hour storm event as well as accumulated sediment. All ponds and <br />associated components including collection ditches, inlet channels, <br />embankments, outlet structures, discharge structures and outlet channels <br />are designed and constructed to ensure long term structural integrity and <br />provide sufficient storage capacity. EFCI utilizes a separate water <br />treatment and recycle pond to collect and retain water resulting from mine <br />dewatering activities. Consequently, it has not been necessary to <br />incorporate mine pumpage volumes in determining sedimentation pond <br />capacity. Discharge structure designs for the sedimentation ponds provide <br />for a minimum detention time of 24 hours and allow for effective <br />dewatering under design storm conditions as dictated by applicable <br />regulations. <br />All areas disturbed by mining and related operations will be reclaimed as <br />soon as operationally practical following completion of mining. <br />Reclamation will involve backfilling and regrading disturbance areas, <br />replacement of topsoil, and revegetation, resulting in re-establishment <br />• of drainage patterns similar to those existing in the pre-mining <br />environment an development of a self-sustaining vegetative community. As <br />a result of effective reclamation, infiltration and runoff relationships <br />will be restored, limiting the time interval over which water quality <br />impacts may occur. Where appropriate, EFCI utilizes localized drainage <br />control measures to prevent or mitigate potential impacts from ongoing <br />operations. Such measures may include use of surface binders and dust <br />suppression agents on haulage roads, topsoil stockpiles, and in active <br />working areas, and placement of straw bales, sediment fence, erosion <br />netting, mulch, berms, stilling basins, sumps and other small structures <br />to control and route drainage, limit surface erosion, minimize flow <br />velocities, and reduce suspended sediment levels. <br />Surface placement of coal refuse materials may effect surface water <br />quality through direct runoff from active refuse placement areas or as a <br />result of groundwater leaching of coal refuse materials where resulting <br />leachate discharges to the surface water system either through the <br />. underdrain system and sedimentation ponds or through underlying <br />colluvial/alluvial terrace deposits. <br />2.05.6-18 <br />