Laserfiche WebLink
Surface Water <br />The probable hydrologic consequences of coal mining .at the Yoast <br />mine in regard to surface water include contributions of sediment to <br />streams from storm runoff, and impacts to streaun water quantity and <br />quality during and after mining. Potentially affected streams and <br />drainages include Armand Draw, Grassy Creek, and Sage Creek. The <br />most significant impact of mining on surface water ~,vill be the effect of <br />spoil spring discharges from the reclaimed mine on siJrface water <br />quality. Seneca Coal Company's predictions of tlhe :magnit:ude of these <br />impacts is discussed below. <br />Sediment Loadin <br />All runoff from areas disturbed during the life of mine will pass <br />through one of five sedimentation ponds prior to leaving the permit <br />area. Discharges from the ponds will be required to meet NPDES <br />effluent limits, and should, therefore, not contribute additional <br />suspended solids to stream flows near the permit area. <br />Following reestablishment of drainage channels and vegetation during <br />reclamation, more runoff from the mine area will occur. However, <br />sediment loads in that runoff should be no lazger than those currently <br />coming from the permit area. <br />Quantity of Surface Flows <br />The largest peak flow recorded in Armand Draw during t~aseline data <br />collection was 0.585 cfs. The presence of a sediment pomd in Armand <br />Draw will attenuate peak flows in that drainage during mining. After <br />mining, flows in Armand Draw will increase due to establishment of <br />spoil springs and additional runoff from the re:clauned azea .Spoil <br />springs aze projected to add approximately O.Oi'3 cfs of base flow to <br />Armand Draw. <br />Spoil springs in Armand Draw and the Pond 11 drainage Kill add year- <br />round base flow to Grassy Creek. These spoil sparing contributions are <br />projected to increase mean flows during irrigation season (June 1- <br />September 30) in Grassy Creek from 0.25 to 0.37 cubic feet per second <br />downstream from the Yoast Mine. 1 <br />Quality of Surface Water <br />The primary impact of Yoast mining operations on surface water <br />quality will be an increase i^ total dissolved solids concentration <br />Yaast Mine 28 July 6, 1995 <br />