Laserfiche WebLink
• constructed to provide effective drainage of both runoff from stockpile <br />surfaces and infiltration through coal stockpiles. Runoff from stockpile <br />areas is collected and routed to nearby sedimentation ponds. Generally, <br />both as an operational and environmental consideration, EFCI limits <br />stockpiled coal inventory. Limited inventory results in rapid stockpile <br />turnover, minimizing the potential for weathering or leaching of coal <br />materials. <br />EFCI will utilize sedimentation ponds and associated drainage structures <br />to intercept, route, retain for sediment control, and discharge disturbed <br />area runoff. Operation of the sedimentation ponds has the potential to <br />affect both surface and groundwater quality by causing changes in water <br />chemistry, increasing TDS levels, decreasing TSS levels and increasing the <br />concentrations of specific mineral components. <br />Disturbed area runoff flowing into sedimentation ponds will be retained <br />to allow suspended sediment to settle out prior to discharge to natural <br />• drainages. During the time that water is retained in the sedimentation <br />structures, some evaporation will occur, resulting in reduction of overall <br />water volume and inherently increasing concentrations of total dissolved <br />solids and specific mineral components. Any changes in surface water <br />quality or chemistry have the potential to effect groundwater resources <br />since surface flows are a component of down-gradient groundwater recharge. <br />Effects of evaporation will be minimized by limiting detention time in the <br />sedimentation structures to that interval required for effective reduction <br />of suspended solids. Given the fact that runoff typically occurs only in <br />response to snowmelt and major storm events, evaporation will be further <br />limited by cold temperature during spring when the majority of snowmelt <br />occurs. EFCI will also monitor sedimentation pond discharge in order to <br />detect any significant changes in surface water quality. If significant <br />changes are noted, EFCI may, with consultation from the CMLRD develop and <br />implement appropriate water treatment plans. <br />It should be noted that seepage from sedimentation ponds will not be <br />• significant due to relatively impermeable underlying strata. Freshwater <br />Pond No. 3 and Process Water and Recycle Pond No. 2 are lined to provide <br />an additional measure of protection against seepage. <br />2.05.6-25 <br />