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Setting: The Level 6 waste rock pile is pad on which outside mine operations <br />occur. It is less than 0.5 acres in size and currently retains several stormwater <br />management practices including pad slope and contouring which routes pad <br />stormwater towards the hillside base and not over the pad edge, berms along the <br />perimeter of the pad confine water from precipitation to the pad footprint, a <br />stormwater infiltration basin is located on the pad to accept stormwater <br />originating from the work area, revegetation of perimeter berm areas with the use <br />of stockpiled soil from initial mine operations, berms alongside the portion of <br />Deadman's Gulch adjacent to the pad to confine gulch flows to the gulch itself <br />and prevent pad stormwater from reaching the gulch, and run-on channels at the <br />toe of the cut slope to route up-slope flows from entering the pad itself. The <br />combination of these features has appeared to be very effective in controlling <br />stormwater within the Level 6 pad. However, in the interest of being <br />conservative, any stormwater flows that may encounter the waste rock may also <br />create acid rock drainage. This is a `potential' or perceived concern that has not <br />yet actually occurred. However- in the interest of exec-e sing eeffseFVa6v <br />'waste s <br />rrt-- 6---'----1 ---1 -° _-C-- *-1- ._.:11 :--1..A- -:-- R..,.,4. - -P--- ,....,,,ol ?,.....l.l.le <br />intended use in per-petuity <br />As per agreement with the Bureau of Land Management, the waste rock pile will <br />be removed from the native Deadman Gulch channel pathway beginning in 2008 <br />when weather conditions allow for construction activities. In the interim, the <br />native flows have been captured and contained with a geotextile lined channel <br />placed within the Deadman Gulch channel with the dimensions of 4 feet wide by <br />4 feet tall and approximately 1,200 feet in length. The placement of the geotextile <br />liner followed manufacturer specifications where segments were overlapped <br />approximately in 10 foot portions and anchored with cement nails (refer to <br />photos) The channel itself was anchored into the hillside where the native flows <br />take the form of a seep. First the seep area was excavated to clean out a <br />workable area to anchor the liner into and to be sure all seep flows would be <br />captured Then segments of geotextile liner were laid down with overlapping <br />edges to prevent wicking of water. The liner was then anchored with cement nails <br />and packed down with soils to provide contouring The channel is thereby <br />blended into the natural setting contours and should not create any concerns. <br />Current site observations indicate that the channel design is sufficient to capture <br />Gulch flows. <br />a. SWMP Administrator <br />Page 11 of 37