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initial organic bed, wetland vegetation plantings, and maintenance of flooded conditions in the wetland <br />zones. <br />The proposed passive treatment system will be constructed in a small ephemeral drainage above the existing 6MN <br />Mine Water Storage Reservoir. It will be accessed from existing mine (6MN Road) and ranch roads, and will <br />require construction of a 2,600 ft light -use road for the initial construction activities and subsequent inspection, <br />monitoring, and maintenance activities. It will be fed by the existing 5 -Main North Pipeline, which is <br />interconnected with the existing mine water handling system, allowing water to be moved from either the 5MN <br />Borehole or TORT Boreholes to the proposed treatment system. The existing waterline will be extended up to 600 <br />feet. The system will discharge to the existing 6MN Mine Water Storage Reservoir, which will allow sampling <br />prior to discharge. The 6MN Reservoir will be modified to include a gated discharge culvert below the level of the <br />existing emergency spillway. A rock -lined discharge channel gill connect to the existing diversion channel, which <br />will be expanded below this junction and armored to effectively handle the design flows. A surge basin will buffer <br />flows from the armored channel to an existing natural ephemeral tributary of Fish Creek. <br />The planned passive treatment system, road, and associated discharge structures will result in approxinnatel} 19.0 <br />acres of new surface disturbance. TC previously completed cultural resource surveys for the associated <br />geotechnical work (MR 16-295) and is consulting with Colorado Parks and Wildlife (CPW) relative to any potential <br />associated fish or wildlife impacts. Available mapping indicates that the proposed disturbance activities will not <br />encroach on any restricted use areas for grouse. TC will provide the CPW consultation letter on receipt. TC is also <br />pursuing required permit approvals with the U.S. Army Corps of Engineers (USAGE) and the CDPHE-Water <br />Quality Control Division (WQCD). Prior to surface disturbance activities, construction erosion controls (wattles or <br />silt fence) will be placed to control runoff and sediment transport from the disturbed areas. Soil materials will be <br />stripped and stockpiled in proximity to the treatment and discharge facilities. Some soil materials may <br />subsequently be used in construction of the wetlands and as cover for the cell embankments to support vegetation. <br />The remainder will remain in stockpile for use in reclamation and will be stabilized with the temporary revegetation <br />mixture. The passive treatment system will remain in use and operation so long as it is needed to provide treatment <br />for mine water discharges. Once discharge ceases, man-made discharge structures will be removed, and <br />modifications will be made to the cell embankments to provide for flow-through, with the cells and associated <br />ponded areas and wetlands remaining. It is recognized that normal surface flows from the contributing ephemeral <br />drainage area will be substantially less than the mine discharge flows, however, the water storage provided by the <br />ponded areas and wetlands will extend the effective flow period. With less water, the wetland areas are expected to <br />shrink, but there will be sufficient water to support small ponds and �\etlands as a permanent habitat enhancement <br />feature. <br />This submittal includes revised PAP text and exhibits addressing the location, configuration, operation, <br />maintenance, and reclamation of the proposed 6MN Passive Water Treatment System. New and revised PAP <br />materials are identified by the attached Summary of Revisions/Additions. We would like to proceed with this <br />project as soon as possible, to take advantage of the 2016 construction season and allow the wetland plantings to <br />establish, and to support our ongoing mining activities. We, therefore, appreciate your consideration, cooperation, <br />and assistance in facilitating timely review and approval of this revision application. After you have opportunity to <br />review the accompanying information, please feel free to contact me with any questions or to discuss submittal <br />materials or related matters. <br />Best regards, <br />Twentymil C <br />Jerr . Ne ton <br />anage ► ironmental Affairs <br />cc: Ed Brady/TC <br />Mike Berdine/TC <br />Brian Watterson/TC <br />