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proposed Bleeder Shaft pad area is less than natural settleable solids concentrations for runoff from undisturbed lands, <br />given similar conditions. <br />The upgradient diversion ditches will be triangular ditches designed to safely divert the peak flow from the 10 -year, 24- <br />hour storm with a minimum of 1 -foot of freeboard and located as shown on Figure 1, Bleeder Shaft Pad SAE. The <br />shaft pad will be constructed such that it slopes toward the gravel filter. The check dam and grass filter efficiency was <br />modeled using the SEDCADTM4 check dam and grass filter utility. Exhibit 5 is submitted to demonstrate that <br />application of diversion ditches, drainage collection ditches, wattles, Curlex blankets, and the sump, rock check dam, <br />and grass filter can effectively control and treat runoff from this area. <br />6MN Mine Water Storage Reservoir and Ancillary Facilities — The 6MN Reservoir installation will include a water - <br />supply inlet pipeline from the 10 -Right Mine Dewatering Transfer Pipeline (includes a pipeline crossing of Fish Creek); <br />the reservoir itself (basin, embankment, emergency spillway, and outlet channel); a clean -water diversion ditch; <br />discharge pump station, pad, and associated light -use road; discharge pipeline to the 6MN Million -Gallon Tank; and an <br />associated topsoil stockpile. The reservoir, emergency spillway, discharge channel, and diversion channel are designed <br />structures, with relevant design information provided in Exhibit BCC. Drainage and sediment control for the remaining <br />components will be addressed through Alternative Sediment Controls (ASC's) and/or Best Management Practices <br />(BMP's). <br />As a limited and temporary disturbance, drainage and sediment control for the pipeline construction activities will be <br />addressed through the application of a package of site-specific BMP's. Prior to initiation of pipeline construction, and <br />as pipeline construction advances, sediment control materials (straw wattles or silt fence) will be placed downslope <br />of the disturbance at any location where the pipeline corridor is within 50 feet of a drainage or stream buffer zone <br />and available soil material will be removed and windrowed adjacent to the disturbance area.. Where the pipeline <br />disturbance is not near drainages or stream buffer zones, existing natural vegetation will provide an effective <br />vegetative filter to address any anticipated sediment control requirements. Progressive backfilling, soil <br />replacement, and revegetation of the pipeline disturbance immediately following pipeline installation will serve to <br />minimize any short- or long-term impacts. .Where the pipeline crosses under Fish Creek, BMP's at the crossing <br />location will include placement of stream buffer zone markers at any point where the pipeline corridor is within 50 <br />feet of the stream buffer zone prior to any activity; completion of the work during low -flows; placement of silt <br />fence or anchored straw bales at least 50 feet downstream to catch any sediment released prior to initiation of work; <br />placement of sediment control materials (straw wattles or silt fence) around the entire side and near stream <br />perimeters of the jacking pit disturbance areas; restrictions on storage or transfers of petroleum products within the <br />buffer zone; and reclamation of the affected areas immediately following completion of pipeline installation. <br />Construction and sediment control details are shown by the design drawings in Exhibit 490. <br />Reservoir slopes and surfaces (out -slope and top of embankment), pad and road out -slopes, and topsoil pile will be <br />stabilized and protected from erosion by seeding with the standard temporary stabilization seed mixture, on <br />completion of construction. The upstream embankment of the Reservoir, emergency spillway, diversion channel, <br />and outlet channel will all be riprapped, per the design specifications. Drainage and erosion control will be <br />addressed on the pump pad surface and light -use road through placement of gravel surfacing materials. <br />Supplemental drainage and sediment protection for the topsoil pile will be provided through placement of sediment <br />control materials (straw wattles or silt fence) around the perimeter of the stockpile until an effective vegetative <br />cover becomes established. <br />Thickener Underflow Boreholes and Pipelines (TR07-60, TR09-69, MR07-221, MR10-242, MR10-248, MR13- <br />270, MR13-273, TR16-86) — TC has or will complete new thickener underflow boreholes in both the SWMD and the <br />EMD, and install new thickener underflow pipelines to convey fine coal refuse, as a slurry, from the washplants to these <br />locations. With the exception of the surface casings and any protective manhole structures for the underflow boreholes, <br />surface disturbance for the Thickener Underflow Pipelines and Boreholes will be temporary and surface activities will <br />be limited to pipeline/borehole installation activities. <br />The l MN Thickener Underflow Borehole is located to the west of the previous CYCC Office Building (Brown <br />Palace) location, along the existing light -use road, and extends approximately 310 feet into the sealed and abandoned <br />mine workings in the SWMD. The 6RT Thickener Underflow Borehole installation is located southeast of the <br />intersection of Routt County Roads 27 (RCR27) and 33 (RCR33), on the north side of Foidel Creek and the <br />TR16-86 2.05-84.5 11/21/16 <br />