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• --~ <br />INSPECTION REPORT - PAGE 2 <br />FILE N0. M-77-342 <br />DATE: September 4, 1985 <br />OBSERVATIONS OF IMPORTANCE: <br />Tailing Dam <br />Face of No. 1 Tailing dam is benched to allow access to each lift. <br />Horizontal Bench is fifty (50) feet wide, backsloped slightly to bench <br />wall which is 1 1/2:1. Topsoil has been replaced on portions of the <br />benching 6-18 inches. Areas with adequate topsoil on level areas <br />support a grass cover with bench walls at 1 1/2:1 and level bench areas <br />with exposed tailing supporting much less to zero grass. <br />2. Areas of bench slopes with thin mantle of topsoil where older tailings <br />are oxidizing are showing signs of vegetation die-off. <br />3. Compaction and/or lack of soil, may be a limiting factor on vegetation <br />on the lower (older benches). <br />4. Overall slope = 3 1/4:1 to 3 1/2:1. <br />Revegetation Test Plots <br />1. Zero topsoil on three (3) feet of tailings with various amounts of <br />lime = zero success. <br />2. Vigor of plants and cover improve with increasing depth of topsoil. <br />RECOMMENDATIONS: <br />1. Mr. Charles Jackson will send the Division the results of information <br />gathered from the tailing revegetation test plots. <br />2. As discussed, the operator must submit a Technical Revision for the <br />reclamation of the tailing ponds. Based upon our observations at the <br />tailing dam revegetation area and the revegetation test plots, it is <br />clear that the current plan will not meet the performance standards. <br />The operator must address final grading of the dam face (i.e., 4:1 <br />horizontal to verticle), the use of waste rock to stabilize the tailings <br />as at the Climax Mine, increasing the depth of topsoil to be replaced <br />over the tailing material, addressing soil loss over time utilizing the <br />universal soil loss equation, and recalculation of the financial' <br />warranty. <br />3. As agreed, this Technical Revision will be submitted during the spring <br />of 1986 at the time the annual report is submitted. <br />JBM/mis <br />3276E <br />