Laserfiche WebLink
The disturbed acreage is limited to 4.] acres upon which the current <br />surface facilities are constructed. Natural drainage over this area is to the <br />North on a slope of less than 66. Little or no top soil remains on the mining <br />bench. Historically, the mining of coal at this site has spanned thirty years; <br />no top soil was ever saved or stored. Une sediment pond, North of the mine <br />bench and adjacent to the meadow will contain water and sediment runoff from <br />the disturbed surface. <br />Runoff from upslope (watershed) areas will travel through diversion <br />ditches around the disturbed mine bench and empty into the meadow. The meadow <br />(alluvial valley) runs the length of Hay Gulch. Historically, cattle have <br />grazed here. Except for a few months each summer, the meadow is usually wets a <br />natural drainage channel, the meadow drains runoff from all gullies, including <br />the mine site and the upslope areas in Hay Gulch. <br />NOTE: Only water from the upslope areas diverted away from the dis- <br />turbed mine bench will be allowed to pass into the meadow. The proposed <br />• settling pond sits at the junction of the mine bench and the meadow. <br />I <br />Surface Hydrology <br />The hydrology map depicts runoff patterns in the mine area. The <br />runoff from the upslope is minimal. But, to channel the runoff that may occur <br />through the mine bench, diversion ditches are proposed. These will iserve as <br />water conveyance systems and will. empty into the proposed sediment pond. <br />Topography controls the natural drainage systems within Hay Gulch, as it does <br />within the permit area. The fact that there are no gullies within the permit <br />area proves the Blue Flame Coal Mine is located in a watershed that is, fairly <br />inactive. The proposed sediment pond (design approved) will be constructed to <br />prevent any water pollution that might occur due to runoff through 4.1 acres of <br />disturbed area. It will be designed to meet the standards given (i.e., ade- <br />quate capacity to handle a ten year-twenty four hour storm event). All runoff <br />that will not encounter the disturbed area will be allowed to precolate (natural- <br />ly into the meadow below. ~ <br />r ~ <br />