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• <br />SOUPH MINE FAN IIJSTALLATICN <br />On December 23, 1991, in conjunction with a minor revision submittal (MR- <br />16) , EFCI requested a Small Area F~cemption for the area to be re~Listurbed <br />by the South Mine Fan Installation. ZYnis area, as shown on the South Mine <br />Fan Installation Map, (Map 30) esrcxnpas_~ approximately 0.46 acres. Zhe <br />entire disturbance area and surrauding lands were previously disturbed by <br />minimm arri other activities related tD operation of the Mon3rrh No. 4 <br />Mine. No significant reclamation of this previous disturbance has <br />occurred with the exception of EFCI's recently ca~leted installation of <br />water bars on and reseeding of the powerline access road. <br /> Both the existi.rg Monarch No. 4 mine workings and planned extensions of <br /> the Southfield working slope to the northwest away fran the surface. <br /> Zhere is no evidence of groundwater discharge to the surface from the mine <br /> workings and none is anticipated. Giv~.n the absence of groundwater <br /> dice-hay~e fr~Bn the mine workings, there will be no minim of surface <br /> drainage and mine discharge. <br /> <br /> Considering the limited disturbance area, the extent of previous <br /> disturbance and the other factors noted above, full scale sent control <br /> for the mine fan installation cannot reasonable be justified. In order to <br /> minimize contributions of suspended sediment to the nearby ephemeral <br /> drainage arri limit effluent water quality impacts, F~'CI proposes to <br /> wnstruct catchment basins and berms prior to site grading or other <br /> surface disturbance or in conjunction with facility construction as <br /> appropriate. A berm will be established below the fan on the outside edge <br /> of the level pad to divert all disturbed runoff to the adjacent catchment <br /> basin. A record berm will be placed upslope from the fan installation to <br /> protect the installation fran upslope drainage. A record catcYmient basin <br /> will be constructed ~letely aroiud the material stockpile. A berm will <br /> be established on the outside edge of the catchment basin to prevent <br /> undisturbed surface runoff fran entering this basin. 'The material <br /> stockpile and associated drainage structures will be located a minitmmi of <br /> 20 feet fran the toe of the adjacent slope. 'This buffer zone will <br />_ <br />• effectively reduce the velocity of overland flow caning off this slope and <br /> minimize any potential for erosion of the diversion berm. Catchment <br /> basins and berms will be used to control disturbed area runoff from the <br />~~~-~+= ~=gym 200 Ra Revised -July 1992 <br />