_INSPECTION - C1982057 ‎(73)‎

• Permit No: C1982057
• IBM Index Class Name: INSPECTION
• Doc Name: Inspection Report
• Inspection Date: 7/28/2010
• Email Name: DTM
• Email Name: SB1
• Media Type: D
• Archive: No

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