Laserfiche WebLink
IMKI <br />On October 23rd through 25th, 2013, a bond release inspection was conducted at the Roadside <br />Portals Mine pursuant to SCC's Bond Release Application (SL -8) submitted August 27, 2013. <br />This was a partial Phase I, II and III bond release inspection of the majority of the Roadside North <br />and South Portals Mine permit area. The postmining land use is Fish & Wildlife Habitat for all <br />areas requested for bond release in the SL -8 application. <br />We began the inspection on the morning of October 23rd by orienting the participants to the areas <br />proposed for bond release with a map and providing some historical information regarding the mining <br />operation itself. During the inspection, participants walked through large portions of the site subject <br />to the bond release request, to allow for visual assessment of compliance with pertinent requirements <br />including backfilling and grading, site stability, blending of regraded land to undisturbed areas, and <br />drainage control for Phase I areas. For Phase II and III release requested areas, pertinent requirements <br />include topsoil replacement thickness, revegetation success, functioning of the reclaimed land to serve <br />the post -mining land use, assessment of erosional features and bare areas, surface and groundwater <br />impacts, and completion of all reclamation obligations. Relevant documentation developed over the <br />past several years is included in previous inspection reports and referenced in this report as <br />appropriate. In addition, Post -Mining Topography Maps, Certified Cross -Sections of Backfilled and <br />Graded Areas including reclaimed Sediment Ponds 6 through 11, and Pond 13, and As -Built Drainage <br />Profiles were included in the bond release application (Tabs 7 and 8) and reviewed by the DRMS <br />during the technical evaluation of the bond release application. <br />BACKFILL and GRADING <br />The reclaimed areas of the mine site were stable with adequate surface water runoff control. Based <br />on observations made during this and previous inspections, the reclaimed areas have been restored to <br />the approved configurations as described in the permit application package (PAP). Observations were <br />made throughout the inspection with regard to erosional stability of the reclaimed landscape. Two <br />areas of concern were noted by the DRMS and the OSM where erosion had occurred in two drainage <br />channels due to the recent prolonged storms and significant precipitation that fell earlier this year <br />during the late summer months. These channels are discussed below under Hydrologic Balance. One <br />other area of concern raised by the OSM during the inspection is located in the southeast corner of <br />the North Portal permit area. This is the location where the Bureau of Reclamation (during Permit <br />Revision No. 5 review) requested that the flume that carried runoff from the East Diversion Ditch 2 <br />directly into the Government Highline Canal be removed so that the flow no longer enters into the <br />canal. With PR -5, the Bureau of Reclamation was involved and provided their approval of a new <br />design to install Ditches D-136, D -D7 and D-138 so that the flow would be directed to a revegetated <br />area adjacent to the canal. As noted during the inspection, there is evidence of recent sheet flow and <br />sediment deposition below the ditches that replaced the flume. This is also discussed below under <br />Hydrologic Balance. The location of the former flume was backfilled and graded and reseeded in <br />October 2012. The G Substation located at the North Portal consisted of 0.5 acres and was backfilled <br />and graded and seeded in September 2008. <br />Page 9 <br />