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TO PREVENT EROSION AND RE-SILTING BEFORE THE WATER REPORTS <br />TO THE RIVER. THE PONDS ARE DESIGNED TO HOLD A SEDIMENT <br />` LOAD OF ONE-TENTH 11110) ACRE-FOOT OF SEDIMENT PER ACRE OR <br />DRAINAGE AREA. THE PONDS CAN RETAIN MORE THAN THE RUNOFF; <br />f~,Qf1,w;~.~1,O.Y.~R:uZ~JFJR. aS7~QR,~.E:V.ENT., WIT.F~,_ A,..FU~L-.L. SED.LM,E.(J,T, LO;A~D.r THE <br />RUNOFF WILL BE RETAINED UNTIL TlIE WATER HAS CLEARED. AT <br />WHICH TIME THE MANUALLY OPERATED DISCHARGE GATES WILL BE <br />OPENED. AFTER DRAINING. THE GATES WILL BE CLOSED TO CATCy <br />FURTHER PRECIPITATION RUNOFF: <br />• <br />WATER QUALITY IS ALSO MAINTAINED THROUGH MEASURES OTHER THAN <br />SEDIMENTATION PONDS AND DIVERSIONS. FILTERING RUNOFF <br />THROUGH BALES OF HAY IS A SEDIMENTATION CONTROL METHOD TO BE <br />USED AS AN ALTEP.NATIVE TO SEDIMENTATION PONDS. SEDIMENTATION <br />PONDS ARE EXPENSIVE BOTH IN TERNS OF MINING COSTS AND IN <br />COST TO THE ENVIROPJMFNT AS THEY DISTROY MUCH GRAZING AND <br />FORAGING GROUND THAT WOULD OTHERIJISE BE UNAFFECTED. THE <br />BALES WILL BE SECURED TO T41E GROUND IM A LINE INTERSECTING <br />THE DRAINAGE FROM REVEGITATED AND LIGHT-DISTURDANCE AREAS. <br />THE SEDIMENT BUILD-UP BEHIND THE FILTERS WILL BE REMOVED AND <br />SPREAD OVER THE MINE REFUSE TO ACT AS A SUBSOIL AND BARRIER <br />HORIZON WHEN THE REFUSE PILES ARE FINALLY REVEGITATED. <br />SMALL LIGHT-ACTIVITY AREAS HAVE BEEN SURFACED WITH CLEANED <br />GRAVEL IN ORDER TO PREVENT SILTING OF RUNOFF WATERS. THE <br />AREAS IMMEDIATELY AROUND THE AIR INTAKE AND EXHAUST SHAFTS <br />HAVE BEEN SURFACED WITH SIX 7Nf,HFS OF GRAVEL AS AN <br />7 <br />