_INSPECTION - C1981010 ‎(81)‎

• Permit No: C1981010
• IBM Index Class Name: INSPECTION
• Doc Name: Inspection Report
• From: DRMS
• To: Graham Roberts
• Inspection Date: 8/15/2013
• Email Name: JLE
• Email Name: SB1
• Media Type: D
• Archive: No

August 15,2013 C-1981-010/Trapper Mine JLE
The 46.8 acres parcel F-A-11,the 70.0 acre parcel F-A-12 and the 47.8 acre parcels Z-A-12 were evaluated for
compliance with the approved post mine topography during previous inspections. These parcels were observed
during this inspection. Overall,these areas blend in with the surrounding topography. Trapper has excavated and
shaped a drainage channel that essentially runs south to north along the boundary of parcel F-A-12. Large
boulders have been stockpiled at various intervals along this channel to be used for check dams.
Parcel K-A-11 was evaluated for compliance with the approved post mine topography during previous inspections.
Overall,this area blends in well with the surrounding topography.
EXCESS SPOIL and DEVELOPMENT WASTE—Rule 4.09;Placement;Drainage Control; Surface Stabilization:
Parcels K-A-10 and K-A-1 lencompass the Horse Gulch Fill. These parcels appear to be in compliance with the
approved post mine topography based on elevation sampling conducted. The underdrain constructed within the
fill was completed in the first quarter of 2010. The north rip-rap channel and the south rip-rap channel have been
constructed. The bottom width seems to vary by a few feet along the channel. The Division measured the
approximate bottom width of the channel in one location and found it to be about 18 feet for the south channel and
12 feet for the north channel.
Both the North and South Rip-Rap channels appear to be functioning as designed and only minor rilling was
observed. Two benches are constructed on the face of the fill. The benches were measured to be about 25 to 28
feet in width. Small"V"channels are constructed at the toe of each bench to drain water off the face of the fill to
the side drains. These drains appear to be clear and functional. Signs of slumping or large settling cracks were not
observed. Larger rills have been noted in the past on the face of the fill above the 2nd bench during previous
inspections. These rills have been repaired. The face of the fill does not appear to exceed the required 3:1
horizontal vertical ratio slope.
HYDROLOGIC BALANCE -Rule 4.05; Drainage Control 4.05.1,4.05.2,4.05.3; Siltation Structures 4.05.5,
4.05.6; Discharge Structures 4.05.7,4.05.10;Diversions 4.05.4;Effluent Limits 4.05.2; Ground Water
Monitoring 4.05.13; Surface Water Monitoring 4.05.13;Drainage—Acid and Toxic Materials 4.05.8;
Impoundments 4.05.6,4.05.9; Stream Buffer Zones 4.05.18:
The Middle Pyeatt Drainage within bond release parcel A-B-10 was walked. The location of this channel was
mapped using a Trimble YUMA GPS unit. The channel appears to be in the approved location. Check dams have
been constructed at various locations within the channel. Side cutting was observed through the majority of this
channel and the side slopes are very steep to nearly vertical in places ranging from 5 to 15 feet in height.
West Horse and Horse Gulch sediment ponds were holding water but were not discharging. Their embankments
appeared stable and vegetated. The primary and emergency spillways were clear and functional.
A portion of the re-established Oak drainage channel has been constructed within Parcel A-B-09. Many rock
checkdams have been constructed in this steep channel. The side slopes of the channel are very steep to nearly
vertical in places where the channel has experienced side cutting erosion.
Number of Partial Inspection this Fiscal Year: 2
Number of Complete Inspections this Fiscal Year: 0
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