2012-05-30_PERMIT FILE - C1981012A ‎(2)‎

• Permit No: C1981012A
• IBM Index Class Name: Permit File
• Doc Date: 5/30/2012
• Section_Exhibit Name: Section 2.05 Operation and Reclamation Plan
• Media Type: D
• Archive: Yes

(4) Ponds, Impoundments and Diversions
The Sediment and Surface Water Control Plans are shown on Maps 13 and 14 for the
East Portal and West Portal respectively. The Operator submitted these plans as a
technical revision to the permit. These revisions have been necessary because of
preparation plant construction, refuse area construction, and the need for more efficient
routing of disturbed water as well as ease of maintenance of the overall drainage system.
The area north of Ditches D11, and D19 to the Highway 12 easement were graded,
covered with subsoil and topsoil, mulched and seeded during August and September of
1990.
The Operator has three sediment ponds which collect surface disturbance runoff from the
East Portal area. These ponds are 004, 007 and 008. A fourth pond, pond 005, was
reclaimed in 2003, as the area serviced by this pond was never used for mining related
activities. These sedimentation ponds and associated diversion ditches have been
designed according to Section 4.05.6 of the DRMS Regulations. In addition, the diversion
structures have been designed utilizing the requirements of 4.05.3 and 4.05.4. Typical
sections of the emergency spillways and embankments of each sediment control structure
are shown in Figure 3, Typical Embankment Cross Section. Typical diversion sections
are provided on Map 13 Sediment and Surface Water Control Plan- East Portal.
Table 20, Ditch Data, is a summary of the diversion (ditch) data relating to Map 13.
Table 21, Culvert Sizing and Table 22, Culvert Sizing Nomograph, provide backup
for culvert sizing as per requested drainage modifications. Table 23, Sediment Pond
Dimensions, is a summary of sediment pond dimensions.
The Operator will control West Portal drainage using ditches, containment areas and
bypass culverts. All structures are shown on Map 14, Sediment and Surface Water
Control Plan -West Portal. Drainage basins are shown on Map 13A, Drainage Basins,
and calculations are found in Exhibit 19, Sediment Design Specifications.
Ditch 27 will direct runoff from Warehouse 1 to Containment Area 2. The total drainage
area is 2.9 acres. A total of 0.28 acre -feet of storage is required to handle the 10 -year 24-
hour event and 0.38 acre -feet of storage is required to handle a 25 -year 24 -hour event.
The three -year sediment volume is 0.02 acre -feet. Ditch 28 will direct disturbed runoff
from a 15.45 -acre disturbed area to Containment Area 1. A total of 1.51 acre -feet of
storage is required to handle a 10 -year 24 -hour event and 2.01 acre -feet for a 25 -year 24-
hour event. The three -year sediment storage volume is 0.07 acre -feet. Containment Area
1 also controls drainage from the non -coal waste disposal area.
TR -59 Page 2.05 -9 Revised 9/30/11