INSPEC40618

• Permit No: C1981041
• IBM Index Class Name: Inspection
• Doc Name: Inspection Report
• Inspection Date: 6/17/2003
• 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.
monitoring requirements had been previously verified by the Division and properly
documented.
a. Prevention of Offsite Impacts
Offsite impacts as described in the evaluation topic narrative outline, include conditions that
affect people, land, water, or structures beyond the designated refuse area disturbance
boundaries. Examples given include untreated disturbed area runoff, offsite sediment
deposition or excessive wind transport of fine waste material or dust, or mass wasting of
refuse or sail beyond approved disturbance areas. No such offsite impacts were observed
at any of the Snowcap Coal Company refuse disposal areas. At each of the refuse areas,
properly maintained sediment control collection ditches and sediment ponds were in place to
treat disturbed area runoff and prevent offsite sediment deposition. Steep refuse pile slopes
reclaimed during 2002 had been properly roughened, seeded, and mulched, and these
practices in combination with construction of terrace drain structures constructed at
specified slope intervals have effectively minimized upland erosion. Promising stands of
seeded vegetation are becoming established in most areas seeded in 2002, although there
are also scattered areas where seeded vegetation is sparse. In general, vegetation on the
2002 seeded areas meets or exceeds typical expectations for initial establishment in a semi-
desert environment, although it is still too early to make conclusions regarding seeding
success or failure. Vegetative cover on older revegetated areas (seeded in 1994} appears to
be sufficient to stabilize the soil surface and prevent excessive erosion.
One offsite impact related concern was discussed during the inspection, related to the new
CRDA-2 upland diversion. The specific concern voiced by OSM upon initially observing the
diversion, was that untreated disturbed area runoff from slopes on either side of the ditch
would be able to enter the channel. The observation is correct, and some explanation of
the history and objectives of the reclamation design is necessary to address the concern.
During active operations, the upland diversion ditch for CRDA-2 had been located on the
steep canyon slope a considerable vertical distancg above the refuse pile. The ditch was
constructed with a relatively low gradient, and crossed several steep erosional chutes that
drained the long steep cliffs above the ditch. The ditch required frequent maintenance, due
to the fact that during periodic high intensity storms, significant volumes of sediment and
debris washed down the drainage chutes and filled in the ditch. Without regular
maintenance, it is likely that the ditch would have failed, and given the former topography
of the ditch and the pile, storm runoff would have flowed onto and across the disposal area.
Large scale erosion of the steep refuse slopes and off-site deposition of eroded coal waste
could have resulted. For these reasons, the ditch was determined to be unsuitable as a
permanent, filial reclamation diversion structure. An alternative design was approved and
implemented during 2001/2002, and the old upper diversion was reclaimed in 2002. The
new diversion was constructed by excavating a significant volume of refuse away from the
upper perimeter of the disposal area, and regrading the top of the refuse pile to create a
topographic barrier. The new, higher gradient, rip rap lined ditch was constructed
immediately upgradient of the pile, at the toe of the steep cutslope which had been formed
by.initial construction excavation. The resulting land-form and ditch will more effectively