_INSPECTION - C1981020 ‎(26)‎

• Permit No: C1981020
• IBM Index Class Name: INSPECTION
• Doc Name: Inspection Report
• Inspection Date: 12/3/2008
• Email Name: MPB
• Media Type: D
• Archive: No

III. COMMENTS -COMPLIANCE
Below are comments on the inspection. The comments include discussion of observations made
during the inspection. Comments also describe any enforcement actions taken during the inspection
and the facts or evidence supporting the enforcement action.
Photographs of all of the post-mine channels are provided in Photo No.'s 4 through 12 at the end of
this inspection report. All of the permanent drainage channels are well constructed and meet the
design criteria. Most if not all of the channels are over-constructed with respect to the design
specifications. Only one channel was noted during the inspection as requiring maintenance and repair.
Channel E shown in Photo No. 13 is washed out at the base of the channel and will require additional
placement of riprap and repair of the channel liner. All other post-mine channels were stable and well
maintained with no other problems identified. Overall the 10 permanent channels have functioned
well with no significant erosion observed since they were constructed.
Several additional silt fence locations will require maintenance and repair. The silt fences located
adjacent to Channel H are either full of sediment or they are no longer installed properly or adequately
keyed in to retain sediment. These silt fence locations near Channel H are shown in Photo No's 14 and
15. In addition, all of the silt fences located at the portal area are nearly full of sediment and need to be
cleaned and properly maintained. Photographs of the silt fences located in the portal area are shown in
Photographs No. 16. The silt fence located at the reclaimed topsoil pile (Photograph No. 17) is also in
need of repair and is no longer functioning. To ensure compliance, please clean out and make all
necessary repairs to all of the silt fences noted above, as soon as practicable.
Backfill and Grading
The majority of the reclaimed areas of the mine site were stable with adequate surface water runoff
control. Observations were made throughout the inspection with regard to the erosional stability of the
reclaimed landscape. The most significant challenge associated with the reclamation at the Munger
Canyon Mine was the construction of stable backfill slopes at grades of up to 2H:1 V in the portal area
and along the portal access road. To ensure that the reclamation of the mine site and road would be
stable, analysis of stability was performed on three areas on the road and two on the mine site. The
stability analysis is described on pages 3-8 through 3-11 of the PAP. The reclaimed configuration is
shown on Figure 3.1-5 through 3.1-7. Reclamation stability cross-sections are provided in the PAP on
Figures 3.1-8A, 3.1-9, and 3.1-9A. As shown in Figure 3.1-9A at Station 49+25 the backfilled area
west of the portals was reclaimed to an overall, approximate 3:1 slope. This was verified with field
measurements using an inclinometer at two locations west of the portals where an average slope of
42% or slope ratio of 2.4:1 was measured. Slopes along the former portal access road and in the area
of the mine portal backfill were extensively roughened by track hoe gouging. A quick growing annual
cover crop ("Quickguard" sterile hybrid) was hand broadcast immediately following completion of
grading and surface roughening. Permanent seeding was done by hand broadcast followed by
mulching in November 2007.
Overall the reclamation project has been very successful and there has been minimal erosion to date.
The graded backfill slopes in the portal area blend in well and conform to the original topography. The
portal access road reclamation generally blends into the adjacent steep slope and outcrop topography.
There are segments of steep road cut exposed along portions of the reclaimed road but these are
approved in the reclamation plan based on backfill stability considerations. A portion of the backfilled