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• The exposure of these sulfides to the atmosphere and to surface water during ~'~`~` the last 113 pears has resulted in their weathering, offidation, leaching, and ''' ~"' erosion. The separation and removal of the ore bearing vein and its accom- ' ;,.,~,t~ • panying sulfides will greatly reduce the degradation of the environment that r'~ occurs when this material is left exposed on the surface of the land. f" ra.~l Because of their composition, acidic nature, and steep slope gradients, topsoil has not developed on these mine dumps. The lack of topsoil on these mine ~ dumps obviates the requirement for removing, segregating, and stockpiling 2 topsoil from these portions of the permit area. ~~pr,./ ~~,dQ,~ re.~,.v`a~,-2~ d- ~t3`~4rws~5~~F~"v.e~ ~ - Reclamation and the future use of the land affected by this milling operation were rnnsiderations in the final site selected for tailings disposition, and in the ~ design of the tailings retention structure. Land reclamation will concentrate on maintaining the structural stability of the tailings dam, protecting the em- bankment from erosion, and establishing the growth of'a permanent. cover of indigenous vegetation on the tailings impoundment area. The plan for reclaiming these dumps. • ees Shrubs Lodgepole Pine Common Juniper Limber Pine K;n,,;k;nn;ck Pondemea Pine Myrtle Blueberry Engelmann Spruce Native Rose • Blue Spruce Bitterbrush Between 20 and 30 trees ranging from 3 to 6 feet in height will be planted every 15 feet in a row along the outer edge of the permit area. Appro,omately 30 shrubs will be planted between the trees. In the event that more than one • species of tree is selected for transplanting, the trees will be planted in pure stands. The area selected for the tailings dam has a slope gradient that varies between 16 percent on the northeastern edge of the site and 14 percent on the south- western edge. When the tailings impoundment structure has reached rte • storage capacity, the outer face of the embankment will have a elope gradient of 35 percent (see Map A). A water runof~'control system was planned t4 enhance and maintain the stability of the ta''l;,,ge dam. Ae much water runofTae possible is diverted • around the tailings pond and away fom the outer edge of the tailings dam em- bankment. Water runoff from above the tailings pond ie controlled by a diversion ditch with a downstream bem. Similar ditches are used to divert water runoff away from the edges and toe of the tailings dam. These ditches were er~avated when the started dike was constructed, and were built and maintained in a manner that reduces water velocity in the conveyance syBtem • and prevents downstream erosion.