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dire t'o. 3 - Design -Y <br /> The sedimentation and drainage control strsetu es at ifsie No. 3 include e tt: <br /> following. Design details are sh7wn in Plates 3-1 and 3-2. Design criterIA <br /> are sLm=ized in Calculation. paraV:aph 5. <br /> a.) Sedimentation. ponds Nlin. ?tecn�ed Storage <br /> 3-1 North Side 0.29 ac-ft <br /> 3-2A South Side combined storage <br /> - 3-2B . South Side of 0.37.ac-ft <br /> Sedimentation pond 3-1 has been constructed to collect and treat sed-M nt- <br /> laden runoff from drainage area 3-1. This pond will also collect mine effluent. <br /> I�:i.ficatiori of this pond include slope increases to 2:1 and 3:1 from misting <br /> 1.5:1.0 slopes, installation of an e ergency spillway, gated outlet kirks with <br /> rip rap protection relocation of urine effluent discb.arge pipes and enll argent <br /> of tj-e pc,•nd. This pond may require lirang with 'butyl nibber (30 rrdl. t'ri ck) to <br /> m-.i-ni:.e potential seepage losses. Such seepage losses cold causse slope <br /> fail-ores either in rl e steep- u ste dix--Q or waathered shale bedrock. - <br /> Sedimentation Pc ids 3-2.A and 3-2B have be--n canstr-L1.cted to collect and treat <br /> sediment laded runoff from drainage area 3-2. The mDdificationof &ese t-y;o ponds <br /> inc'1 ude increasing down str e m and test,eam slopes from 1.5:1 to 2:1 and 3:1, <br /> insta"Llation of an emergency spil.ittiay and gated outlet w ks w-i.th rip rap protec- <br /> tion. <br /> R=,off from -,Athin the dist=bed pad areas will be confi;.ed and diverted to <br /> the ponds by uxDd crate regrading of roads aid appropriate plac%e-_n—_,t of yea:..th <br /> TI-a remoff from adjacent areas -v.d.11 be diverted by ditches aid earth berms. <br /> The r.�.off from land above the higg_-mall .Till be collected by an e sting aba�dored <br /> road that traverses the entire hi§--wall. <br /> NOTE: For design of new #3 pond (lower coal bin) contact <br /> . Mid-Continent Environmental Coordinator <br /> -ti- <br /> 4E <br />