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DIVERSION. OF THE TIIRE.E PONDS AT THE MINE SITE, TWO ARE . <br />UTILIZED FOR RUNOFF CONTROL IC03 6 004) AND THE THIRD (002) <br />IS USED ONLY FOR THE TREATMENT OF MINE WATER. RUNOFF FROM <br />THE PARKING LOT, STORAGE YARD AND ALL AREAS WEST OF THE <br />SLOPE EXCAVA770N, TRESTLE. AND SILO FLOWS TO POND 003 WHICH <br />IS LOCATED TO THE NORTH OF THE MINE SITE. RUNOFF FROM THE <br />SLOPE EXCAVATION. SPOIL DUMPS AND ALL AREAS EAST OF THE <br />TRESTLE AND SILO. IS CHANNELED INTO POND 004 WHICH IS <br />LOCATED NORTH EAST OF THE MINE SITE. THE RUNOFF FROM 7HE <br />RAILROAD YARDS IS ALSO CHANNELED TO THESE PONDS. WATER FROM <br />THE SEWAGE TREATMENT PLANT, OF HIGH ENOUGH QUALITY FOR <br />DIRECT DISCHARGE. FLOWS THROUGH POND 004. NPDES DISCHARGE <br />POINTS 002. 003. AND 004 CORRESPOND WITH THE POND NUMBER <br />{ DESIGNATIONS FOR EASY IDENTIFICATION. ,. <br />TABLES 3 AND 4 LIST AND DESCRIBE ALL DRAINAGE AREAS APID <br />CHANPJELS RESPECTIVELY. SETTLEMENT TIMES IN THE PONDS IS <br />CONTROLLED BY PERFORRATED DRAINAGE RISERS AS WELL AS <br />MANUALLY OPERATED STOP-GATES AT THE DISCHARGE BOXES. <br />BECAUSE OF THE MANUALLY CONTROLLED DISCHARGES SHORT- <br />CIRCUITING OF RUNOFF CAN BE ELIMINATED AND THE ENTIRE RUNOFF <br />LOAD SUFFICIENTLY SETTLED PRIOR TO DISCHARGE. THE EMERGENCY <br />SPILLWAYS WILL HAVE MORE THAN ONE FOOT OF FREEBOARD WHEN <br />PASSING THE PEAK FLOWS OF THE DITCHES FEEDING THE PONDS. <br />THEY WILL ALSO PASS THE RUNOFF FROM A 25YR-24HR STORM EVENT <br />WITH AN EVEN GREATER FREEBOARD. THE POND DISCHARGE POINTS <br />HAVE CONCRETE BOX STRUCTURES AND RIP-RAP DISPERSION BASINS <br />6 <br />