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steep reclaimed slopes at the Colowyo Mine. While Colowyo did implement some <br />of the ideas during the 2009 reclamation season (contour ditches and ripping the <br />topsoil prior to seeding), the Division is requesting a comprehensive and detailed <br />plan for controlling the runoff from the reclaimed slopes, including, but not limited <br />to, contour ditches, ripping, straw bales, reconstructed drainage channels, stock <br />ponds and the possible addition of non-NPDES sediment ponds within the <br />reclaimed area. This plan needs to be specific enough for each of the <br />pits/watersheds to address their unique characteristics. The plan must be prepared <br />by Colowyo and approved by the Division ahead of reclamation and with <br />sufficient detail to ensure proper implementation in the field. The locations of <br />runoff control measures, such as contour ditches and stock ponds, need to be <br />planned prior to reclamation to ensure they function as designed and have the <br />desired effect of controlling and slowing the runoff and providing adequate <br />sediment control. While a minor amount of "field fitting" may be necessary, the <br />location should be well thought out based on the topography and other <br />characteristics of the watershed. Sediment and runoff control features should be <br />located on a map, to ensure that they are properly located and in the necessary <br />area(s). This plan will need to be submitted no later than 25 June 2010 so it can be <br />implemented in the 2010 reclamation season. <br />10. Map 33 shows the post-mining drainage channels for the Colowyo Mine. This <br />sheet has a drawing of the Prospect Ditch (with a length of approximately 3,300 <br />feet). There is also a smaller channel profile farther down on the sheet that shows <br />the Prospect Ditch-Lower Segment (approximately 1,500 feet). This lower <br />segment of the Prospect Ditch is not a continuation of the Prospect Ditch since the <br />ending elevation of the Prospect Ditch is approximately 7,025 feet and the starting <br />elevation of the Prospect Ditch-Lower Segment is approximately 7,125 feet (it is <br />impossible for the two segments to join up). Additionally, there is not a Prospect <br />Ditch-Lower Segment shown on Map 41 - Watershed Boundaries for Hydrologic <br />Modeling (which shows all of the post-mining drainage channels), or any other <br />map (specifically Map 12 - Hydrology South Area). Finally, there does not appear <br />to be a SEDCAD design for this ditch in Exhibit 7. Please provide the Division <br />with information regarding this ditch segment, including its location on the <br />appropriate maps (Map 12 and Map 41) and SEDCAD modeling in Exhibit 7. <br />11. Colowyo has constructed sumps to control runoff from and around the haul road to <br />the Gossard Loadout along the access road in Taylor Draw, to the West Pit Pond, <br />East Taylor Pond and West Taylor Pond.,. These sumps are best management <br />practices and are not considered a part of the sediment control system. Sump 5, <br />does not appear to be functioning properly. There is almost always mud and water <br />backing up along the Taylor Draw road at the location of this sump, occasionally <br />drying in the late summer months. This accumulation of mud and water is not <br />what the sump was intended to do. Colowyo must provide a plan to remedy this <br />problem. Please include a timetable for the completion of the plan in the field to <br />remedy the surface drainage and sediment accumulation problem along the Taylor <br />Draw access road. <br />Colowyo Mine <br />Permit No. C-1981-019 <br />2010 Midterm Review <br />10 May 2010 <br />11