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storage. Sediment from the pond at the 60 per cent <br /> volume level will be included as part of the routine <br /> sediment control maintenance at the mine to ensure <br /> compliance with CMLRB regulations for pond effluent <br /> water quality. (35 ppm average-70 ppm max. ) <br /> NOTE : No underground water will go into these <br /> II. Mine 5 Area Ponds (updated 1986) <br /> A. Sediment Storage Volume 717 .17 (e) (2) <br /> • " There is an error in transfer of sediment delivery <br /> to the ponds which has resulted in undersizing of the <br /> sediment storage volume. Specifically, table 5a, <br /> pages A-6 uses the unit sediment yield factor values <br /> from column 3 , table 4c, page A-5 rather than the <br /> estimated annual sediment yield in column 5 of this <br /> table. (Although mine areas, #3 and #4 are not being <br /> reviewed at this point in time , the same error was <br /> made with respect to calculation of sediment storage <br /> volumes for these ponds as well. ) As a result, the <br /> sediment storage volume for Pond 5-1 is undersized <br /> by 0. 1 AF (designed currently for 0 . 24 AF; required = <br /> 0. 34 AF) . " <br /> • The sediment contained in underground water dis- <br /> charged into pond 5-1 has not been estimated. The <br /> pond must be sized to accomodate one year of sediment <br /> from the underground water discharged from the mine. " <br /> 0• "If pad #5 is covered with coal, the K factor of <br /> 0 . 35 may not be correct; a K factor Of 0 .70 may be <br /> more appropriate as discussed above. " <br /> This item has been amended for Mines 3 , 4 , and 5 as we <br /> discussed in our telephone call on April 22 , 1980 . The <br /> sediment storage capacity for Pond 5-lA is estimated to <br /> be 0. 80af (see attachments) . This figure includes 3-year <br /> storage for mine effluent. (Assuming average 40 ppm sus- <br /> pended solids and 0. 2 cfs average flow. ) <br /> The mine operator however, does not intend to discharge <br /> mine effluent at #5 mine. Number 5 mine pad areas are <br /> not covered with coal and black shale dust. our initial <br /> calculations on the sediment yield delivered to pond 5-1A <br /> remain as before. <br />