_INSPECTION - C1992080 ‎(2)‎

• Permit No: C1992080
• IBM Index Class Name: Inspection
• Doc Name: Inspection Report
• From: DRMS
• To: Mike Savage
• Inspection Date: 9/30/2013
• Email Name: MLT
• Email Name: SB1
• Media Type: D
• Archive: No

September 30,2013 C-1992-080/Carbon Junction Mine MLT
with notable daily totals of 0.81" on the 10th; 1.02" on the 12rh; 1.41" on the 14th; and 1.49"
on the 22'
• None of these individual daily totals is sufficient to qualify as a 10-year 24-hour event(2.4"),
but the nature of monsoon storms results in highly variable intensities across an area. No
hourly totals, to measure the short-term intensity of the various storms, were obtained.
Without a rain gauge having been placed and monitored at the site, we are unable to
determine that a design event (2.4" in 24 hours) had occurred. Evidence of recent heavy
precipitation and runoff was plentiful across the permit area.
Upper Carbon Junction Channel
• The channel at the foot of the lower North Pit slope was well-vegetated. Although it
appeared to be generally stable, we observed that the "low-flow" channel had increased in
width (Photo 1) over what was seen on the previous inspection.
• Grasses were laid down flat in the direction of flow, giving evidence as to of the force of the
flow(Photo 2).
• Some head-cutting had occurred at the nick point created in the channel's profile by
breaching of the diversion berm in 2012. A cluster of block-shaped boulders appeared to
have stopped the erosion from moving further upstream (Photo 3). The erosion was not
severe, but plans for lining this segment of the channel will likely be required with TR-17.
• The channel low spot described in the Aug. 27, 2013 inspection report that formed
immediately upstream of the sediment fan (at the terminus of the temporary diversion berm)
had collected a large volume of fresh sediment (Photo 4).
• The channel behind the temporary diversion berm experienced additional erosion, and a new
volume of sediment was added to the fan that had formed previously.
Carbon Junction Permanent Diversion
• Sediment, still wet in some spots, had been deposited in the flatter stretches of the permanent
diversion channel (Photo 5) and at the outlet end of the twin 66" culvert pipes.
• At the downstream end of the riprapped section, the diverted flow is directed into a tributary
of Carbon Junction Canyon. Forest litter had been washed away from the floor of the
tributary, exposing bare ground and cobbles for its entire length (Photo 6).
East Collection Ditch
• Due to the recent precipitation events, a sizable puddle of water had formed at the southern
end of what remains of the East Collection Ditch, near the former shared use area (Photo 7).
During reclamation, the outlet ends of a triple set of culverts were buried, and the
downstream ditch was filled in. However, the culvert inlets were left exposed, and the
upstream segment of ditch was not reclaimed and graded.
• This problem (ponding of water due to incomplete reclamation of the ditch and culverts)
has been noted in previous inspection reports. This issue could be cost-efficiently
addressed later this year while equipment is on site for the TR-17 and NOV abatement
work in the Carbon Junction Channel.
Number of Partial Inspection this Fiscal Year: 2
Number of Complete Inspections this Fiscal Year: 1 Page 3 of 11