_ENFORCEMENT - C1981017 ‎(9)‎

• Permit No: C1981017
• IBM Index Class Name: Enforcement
• Doc Name: Bid Documents ‎(IMP)‎ CV-91-023
• Violation No.: C-91-023
• Media Type: D
• Archive: No

4 -
Provide for construction and maintenance of siltation structures at
culvert inlets and switchback ditch outlets (similar to BAT ponds
at Arctic Circle) . Where warranted and where access and terrain
allow, provide for construction and maintenance of larger siltation
basins or sediment ponds , which would be designed and maintained to
provide sufficient settling time for water to meet applicable
settleable or suspended solids limits prior to discharge.
Locations where large siltation basins or sediment ponds should be
considerea include the following:
Existing BAT ponds below Mine 1 .
Bowl shaped erosional "blow out" on Drainage B-5 at approximate
Sta. 30 + 00 on Road B.
Drainage below B-3 culvert outlet, adjacent to the small area
exemption bench south of the Rock tunnel area.
Meadow below F-3 curve adjacent to Mine 3 lower bin pad . Drainage
from RD-4 ditch outlet could be routed through a pond at this
location.
Lower end of long meadow on Road F. Pond would treat drainage from
a significant segment of road and road related erosion. Pond site
is adjacent to road curve just above proposed culvert F-3N.
Problem: Excessive erosion or sedimentation from road cuts and fills (see
NOV C-91-018)
Contributing factors :
- Steep slopes , unstable soils
- unsatisfactory vegetation
- Improper drainage
- Slope instability (lower road F)
- Berm material pushed over downslope
Possible approaches :
- Revegetate slopes amenable to seeding.
- Construct siltation structures where feasible.
- Construct and maintain straw bale dikes or silt fence along base of
any road fill slopes which drain directly into a water course with
no vegetative buffer between fill and stream.
- Reduce and revegetate over-steepened fill slope crests .
- Avoid pushing berm material over outslope .
- Develop stabilization/reclamation plan based on geotechnical
evaluation of Road F landslide .
Problem: Maintenance/reclamation of light use roads serving ancillary
facilities and monitoring locations .
A number of poorly maintained light use roads exist within the
permit area. All such roads which are currently used or which have
been used by Mid-Continent since 1977 need to be documented within
the permit and depicted on appropriate permit maps . Drainage
control , maintenance and reclamation plans for such roads and