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<br />Mr. Dean Massey <br />April 26, 1978 <br />Page Two <br />We feel this combination of testing material for its <br />chemical makeup and of retaining run-off from the area <br />will prevent any deterioration of water quality. <br />During our discussion about the waste dump it became <br />apparent that some clarification of terms might be in <br />order so that the board can fully understand our refuse <br />disposal plans. This waste rock material will be laid <br />down in the designated areas in "lifts" which will not <br />exceed 3'. Compaction of each lift will be affected <br />by the loaded haulage trucks driving over the most <br />recently laid lift in order to start the next lift. <br />The work will be staged so that the loaded trucks must <br />travel over every lift, thereby compacting it. Several <br />lifts will be laid down and separately compacted to form <br />a "bench". The number of lifts used to create a bench <br />will be dependent upon the site specific conditions of <br />the terrain. The plans call for an overall slope of <br />3:1 in the refuse area, so each bench may vary in terms <br />of the number of lifts required to create such a slope. <br />Once a bench is completed, a terrace will be placed on <br />top of that bench to facilitate drainage and another <br />bench will then be laid on top of the first bench. <br />Several benches (again, the number depending solely upon <br />the site specific terrain) will go to make up a "stage" <br />as depicted on Plate 1 of the reclamation plan. <br />Once a bench is completed the topsoil (which will have <br />been removed from the area earlier and stockpiled) will <br />be replaced on the bench in 15 to 18 inch layers and the <br />bench will then be reseeded and mulched. Reclamation <br />will proceed as contemporaneously as possible to the <br />completion of the bench. In no case will reclamation time <br />of a completed bench take longer than one year from its <br />completion. <br />As stated in the plan, the waste benches will be <br />constructed according to the 1976 MESA criteria cited <br />in the mine plan. The MESA specifications are accepted <br />engineering techniques in soil and bench stability and a <br />refuse embankment built to these specifications should be <br />inherently safe. We feel that your question concerning <br />the "static safety factor" of these refuse slopes can be <br />adequately answered by saying that these benches are being <br />constructed to nationally accepted specifications and a <br />professional engineer has designed these embankments. <br />Y ,..I I <br />