PERMFILE127244

• Permit No: C1981022A
• IBM Index Class Name: Permit File
• Doc Date: 7/6/2004
• Section_Exhibit Name: 2.05 Operation and Reclamation Plans
• Media Type: D
• Archive: Yes

.Sertian - 2.05.3
and modification of Sedimentation Potid B and the Substation No. 3 Sedimentation Pond and
• associated ditches were prepared or modified by Thomas E. L.eidich, P.E. No. 31459.
Detailed design plans for Sedimentation Pond C and the associated ditches and culverts for both the
West Valley Fill and associated haul road were prepared by or under the direction of Greg Eddy, P.E.
No. 31270. These plans were reviewed and modified to address specific DMG concerns b}' William
P. Balaz, P.E. No. ] 7129.
Detailed design plans for culverting the middle portion of Elk Creek, the collection and diversion
ditches and alternative sediment control measures implemented Eor the Elk Creek Mine surface
facilities, and Sedimentation Pond D were prepazed by or under the direction of Thomas E. Ixidich,
P.E. No. 31459, and Daniel]. Keuscher, P.E. No. 33307.
Detailed design plans for Pond E and the dean-water diversion and disturbed area runoff collection
ditches and culverts for both the II West Coal Refuse Facility and associated roads were prepazed by
or under the direction of Thomas E. I,eidich, P.E. No 3]459.
Mine Water Storage and Discharge -Mine workings in both the Sanborn Creek B Seam Mine and
the Elk Creek D Seam Mine produce sufficient water that dewatering is required in conjunction with
mine development and active mining operations. To the extent reasonably feasible, mine dewatering
flows are routed to lazge underground sumps for temporary storage and to allow suspended solids in
the water to settle out. Accumulated water is then recovered and pumped back into the mine watec
system for reuse. Any excess mine water which, exceeds operational usage requirements and active
storage capacity is dischazged to the surface.
• For the Sanborn Creek Mine, excess mine dewatering Eows aze pumped from the underground sump
to an existing mine water set[ling pond designed to provide additional retention time to allow
suspended solids to settle from the water prior to dischazge to Sanborn Creek. The mine dewatering
pond is a totally incised pond with a bottom elevation of 6,056 feet and atwo-foot deep collection
ditch around the perimeter of the pond. The up- stream, interior sideslopes of the pond are 2H:1 V.
The pond can be dewatered through a 2-inch dewatering pipe with an invert elevation of G,OG0.5 feet,
which effectively provides 4.5 feet of sediment storage. OMI visually monitors sediment
accumulation in the mine pond annually during the third quarter. When the sediment in the pond
reaches an average elevation of 6,059 feet, or 1.5 feet below the primary spillway invert, it will be
cleaned out. A backhoe will be used to excavate the sediment and the sediment will be hauled to and
placed in the active coal refuse and mine development waste disposal area.
On completion of active mining operations in the Sanborn Creek Mine, it is anticipated that pumping
will cease, the mine workings will be allowed to flood, and that the mine dewatering pond will be
removed and the associated disturbance area reclaimed. Pond removal will involve removal of
discharge structures, backfilling the pond basin, grading the pond area, replacing available soil
material, and revegetating the regraded azea. Design information for the Sanborn Creek Mine
Dewatering Pond is provided in Exhibit 2.05-E3, Drainage and Sediment Control Plan, and pond
design configuration is illustrated by the Sanborn Creek Mine Dewatering Pond Map, (Map 2.05-M-
SH).
Dewatering flows from the Elk Creek D Seam Mine are expected to contain lower levels of
suspended solids based on available water quality information and the design of the D Seam sump.
Secondary containment in a pond will, therefore, probab]}' not be necessary to meet applicable
effluent standards. Any dewatering flows which exceed the active capacity of the Elk Creek Mine
• underground sump will be pumped from the sump to the Elk Creek Mine head tank for temporar}>
~ storage and reuse in [he mine water system. If flow volume exceeds operational requirements and the
capacity of the storage tank, any excess dewatering flows will be discharged though an overflow valve
and discharge line to Elk Creek.
1fUi'CRF 2.05-33 Revised June 2003