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y <br /> July 28,2010 C-1982-057/Seneca II-W Mine DTM <br /> F <br /> missionpermit#82R0542F has been cancelled by the Air Pollution Control Division(APCD),and a letter <br /> llation is on file. Adam Wozniak of APCD confirmed in a follow-up phone conversation that an APCD <br /> not required unless there areactive extraction or processing operations. <br /> The NPDES permit was amended effective 7/1/2010, due to transfer of Discharge Points 002, 003, and 004 to <br /> NPDES Permit CO-0048275, for Sage Creek Mine. <br /> BACKFILL and GRADING—Rule 4.14 <br /> ❑Contemporaneous Reclamation 4.14.1; Approximate Original Contour 4.14.2;Highwall Elimination <br /> 4.14.1(2)(f); Steep Slopes 4.14.2,4.27; Handling of Acid and Toxic Materials 4.14.3; Stabilization of Rills and <br /> Gullies 4.14.6: <br /> Original Permit Area <br /> Backfill and grading compliance including hillslope gully and permanent channel stabilization work within the <br /> original permit area watersheds was closely evaluated during earlier inspections in 2010, and as a part of Phase I <br /> bond release evaluation for SL-2, in 2009. Maintenance grading and channel repair work was initiated in the <br /> original permit area earlier in 2010, although some maintenance work as addressed in the 2010 Rill and Gully Map <br /> and identified by the Division in previous inspections remains to be completed. The original permit area <br /> reclaimed watersheds were viewed from the primary roads during the inspection,but drainages were not <br /> extensively walked. No concerns were noted that had not been previously addressed. <br /> South Extension Area <br /> Numerous erosion control"surge structures"were constructed along the primary permanent drainage channels in <br /> the 016 and 017 watersheds during the 2009 field season, in response to significant channel erosion caused by <br /> extremely heavy runoff in the spring of 2009. Drainage channels that had been extensively damaged by the heavy <br /> runoff were regraded and repaired with new riprap and TRM liner installation. The surge structures appear to <br /> have largely functioned as designed this spring, and channel erosion is much less extensive and less severe than in <br /> 2009 (although maintenance will still be necessary in numerous locations). Snowmelt runoff was moderate in <br /> 2010, and high intensity rainfall events that impacted the South Extension watersheds in 2009 did not occur in the <br /> spring of 2010. Vegetation in the watersheds is now beginning to provide an effective cover in most areas. The <br /> combination of surge structures and increasing vegetative cover should minimize the potential for future erosion <br /> on the scale that occurred in 2009. <br /> SCC has not yet initiated rill and gully and permanent channel stabilization work in the South Extension Area this <br /> year(operator indicated the focus of work so far this summer had been at Yoast Mine). As noted in previous 2010 <br /> DRMS inspection reports,channel maintenance will be necessary in a number of locations along various channel <br /> segments in the 016 and 017 watersheds,particularly in locations immediately downstream from surge structure <br /> discharge pipe outlets. In several locations previously observed,TRM liner in these sites had been undercut or <br /> flow had scoured into the channel side slopes, and repair including regrading and heavier armoring will be <br /> Number of Partial Inspection this Fiscal Year: 0 <br /> Number of Complete Inspections this Fiscal Year: 1 <br /> Page 3 of 19 <br />