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• Run-off from up-slope (watershed) areas will travel through d version <br />ditches around the disturbed mine bench and empty into the meadow. Th 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 wet; a <br />natural drainage channel, the meadow drains run-off from all gullies, including <br />the mine site and the upslope areas in Hay Gulch. ICI <br />NOTE: Only water from the up-slope areas diverted away fYom the <br />disturbed 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 />SURFACE HYDROLOGY: <br />The hydrology map depicts run-off patterns in the mine area. The <br />run-off from the up-slope is minimal. But, to channel the run-off that may <br />occur through the mine bench, diversion ditches are proposed. These will serve <br />as 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 prove s'that BLUE FLAME COAL P1INE 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 run-off through the 4.1 <br />acres of disturbed area. It will be designed to meet the standards given <br />(i.e., adequate capacity to handle a ten year - twenty four hour storm event.) <br />All run-off that will not encounter the disturbed area will be allowed to <br />percolate naturally into the meadow below. <br />As mentioned earlier, the Hydrology Map shows proposed open channel <br />and pond construction. Undisturbed water percolates naturally into the meadow, <br />and disturbed water is diverted into the sedimentation pond. There should be <br />no effect on water quality in Hay Gulch attributable to the BLUE FLAME COAL <br />MINE, because the pond collects all disturbed water. The quality of this water <br /> will be monitored. Samples taken at the emergency discharge end of the pond <br /> will determine any change in the quality of run-off. Water contained in the <br />. pond will not be discharged, but allowed to evaporate. The pond will be a <br /> square structure of 50' x 50' at the top an d 46' and 46' at the bottom. This <br />r <br />