_INSPECTION - C1994082 ‎(55)‎

• Permit No: C1994082
• IBM Index Class Name: INSPECTION
• Doc Name: Inspection Report
• Inspection Date: 2/11/2010
• Email Name: DTM
• 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.
General Comments
This was a monthly DRMS partial inspection, combined with a site visit by Duane Matt and Christy Hulsman of
the OSM Denver Office. Mr. Matt and Ms. Hulsman were on site to make observations pertinent to a national
OSM effort to assess conformance with Approximate Original Contour(AOC)regulatory requirements. Yoast
was one of several Colorado mines selected for the evaluation. OSM engineering staff had reviewed relevant
permit documentation and maps in the Denver DRMS office prior to the field verification visit.
Weather was cloudy and cold, with occasional light snow flurries. Deep snow in almost all areas made
observations difficult, and access was limited to the lower portions of the PM-12, PM-13, and PM-14 watersheds
located adjacent to the Sage Creek county road, along the western perimeter of the reclaimed area. A portion
of the PM-12 watershed was walked during the inspection, while observations of the PM-13 and PM-14
watersheds were made from the road, due to deeply drifted snow and exhaustion from hiking through drifts in
the Pond 12 watershed. The main access road into Yoast from 20 Mile Road has not been maintained through
the winter and is impassable due to deep snow.
Backfill and Grading
Lower portions of the Pond 12 watershed were inspected/observed by hiking up to and along the top of the
ridge northeast of Pond 12, along the crest of the slide zone and around the east end of Topsoil Stockpile"U.
South facing reclaimed highwall slopes were traversed as far east as Channel PM-7. Lower slopes and
segments of Channels PM 6-2 and PM 6-3 were walked on the return back to the vehicle, parked on the Sage
Creek Road west of the Pond 12 embankment. Snow cover ranged from 1'to over 4' deep, with the exception
of steep south exposures in the immediate vicinity of the Pond 12 slide zone and some locations along the
upper perimeter of the south facing reclaimed highwall slope. Two inclinometer slope readings were taken
during the walk-about. One slope measurement was taken along what appeared to be typical reclaimed
highwall slope, approximately 100 yards southeast of Topsoil Stockpile"U, in the PM 6-2 watershed; slope was
36%. The second measurement was a profile along a segment of Channel PM-7, immediately downstream of
the culverted temporary road crossing; slope measured was 30%. From comparison of PMT Map Exhibit 20-2
and Channel Profiles Exhibit 20-213, the channel slope measurement appears to have been made along a
channel segment with a design slope range of 27.6% to 35.3%.
Several piezometers and exploratory trenches were observed in the vicinity of the Pond 12 slide. These are
associated with sub-surface geologic and hydrologic investigations undertaken to allow for development of a
slide remediation plan, which was submitted to the Division on February 16, 2010.
The areas of the Pond 12 watershed that were walked and measured during this inspection will not be included
in the Division's pending Phase 1 bond release approval proposed decision, due to the extent of remaining slide
repair, road removal, drainage stabilization, and final grading work. Refer to the Division's SLA inspection
issued 10/13/09 for details.
Hydrologic Balance
Ponds 12, 12A, 13, and 14 were observed. All ponds were iced over and snow covered, and no problems were
noted. Pond 12 was discharging clear flow due to inflow from spoil spring discharge. Ponds 12A, 13 and 14 did
not appear to be discharging.
There was no activity evident and no problems were noted that have not been addressed in previous
inspections.
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