2008-09-16_PERMIT FILE - C1982056A ‎(4)‎

• Permit No: C1982056A
• IBM Index Class Name: Permit File
• Doc Date: 9/16/2008
• Doc Name: Pages 2.05-65 to 2.05-122.1
• Section_Exhibit Name: 2.05 Operation and Reclamation Plans Part 2
• Media Type: D
• Archive: Yes

in the Area 1 Pit. A manhole with manual valves or automated control valves will be used to control flow to the
Washplant.
• Washplant I Thickener Overflow Sump (SUperseded by TR07-59 Washplant II) -The Washplant 1 Thickener
Overflow Sump, located adjacent to the Thickener Tank in the Washplant I area, as shown on Map 24, Surface
Facilities, and by Figure EX8w-1 in Exhibit 8w was excavated during Washplant construction to serve as a catch
basin for the contents of the Thickener, if required for maintenance or under upset conditions. Impoundment
design, operation, maintenance, and reclamation information is provided in Exhibit 8w. While it has not been
necessary to utilize the basin for this purpose, it is occasionally used to collect and retain .minor quantities of
Washplant wash-down water. As an incised and closed basin (ie: no outlet) the only inputs are thickener overflow,.
wash-down water from the Washplant, or minor incident precipitation, which are subsequently pumped back into
the system by a portable floating pump installation. Water level in the sump is monitored and managed as part of
the ongoing plant operations.
Washplant II Thickener Overflow Sump~TR07-59 Washplant II) -For discussion of Washplant II Thickener
Overflow Sump please refer to previous discussion under Rule 2.05.3(3), Mine Facilities.
6MN Mine Water Storage Reservoir (TR07-61) -The 6MN Storage Reservoir will be used to provide back-up
storage for TCC's 10-Right Mine Dewatering Well, allowing the well to pump continuously at full capacity,
providing buffer storage for pump maintenance or failure, and limiting the distance over which the mine water must
be transferred. The 6MN Storage Reservoir is designed as a closed reservoir, with no discharge, and provision for
adequate operating free-board to allow for storage of runoff from a small upslope drainage area. TCC will remotely
monitor and control reservoir water level, and mine water discharge to and from the 6MN Storage. Reservoir, to
maintain the water level at or below design storage capacities, and to maintain the design freeboard, at all times.
Even though the 6MN Storage Reservoir has been designed and will be operated as a closed reservoir, a single
open-channel emergency spillway has been incorporated into the design in compliance with applicable regulatory
requirements for impoundments. Any discharge of stored mine or stormwater from the 6MN Storage Reservoir,
.will be directly to the mine water system, with no discharge through the emergency spillway to natural drainage.
The location, configuration, and components of the 6MN Mine Water Storage Reservoir installation are shown on
Map 24 (sheet 2 of 3), Surface Facilities and Freshwater Systems. Related design information is provided in
Exhibit 490, 6MN Mine Water Storage Reservoir -Design Drawings, including a design stability analysis for the
pond embankment. Because the. proposed Reservoir storage volume is greater then 20 acre-feet, design and
compliance documentation have also been submitted to the Mine Safety and Health Administration (MSHA) for
review and approval.
SMALL AREA EXEMPTIONS AND ALTERNATIVE SEDIMENT CONTROLS
The CDMG/CDRMS has approved several Small Area Exemptions (SAE's) and Alternative Sediment Controls
(ABC's) within the permit area. Effective drainage and sedimentation control in these areas will be achieved by a
variety of methods, including gravel or asphalt surfacing, vegetative filters, installation of fabric filter fences, rock
check dams, gravel filters or berms.
Rockdust Tank
A SAE for sedimentation control has been granted for the rockdust tank and truck access/unloading area. The total
disturbance will be approximately 0.5 acres. Of the total, 0.3 acres will be surfaced with pit run gravel, which acts
as an infiltration screen for any overland flow associated with the rockdust tank and access/unloading area.
Estimated peak flow from the area for the 10-year, 24-hour event is 0.04 acre-feet. Runoff from the topsoil pile is
controlled by a berm/swale/rock filter system. In addition to the infiltration screen, flow from the tank and
unloading area is conveyed by means of swales and berms to a gravel filter. These measures, in conjunction with
existing vegetation, are effective in controlling runoff from the area, as observed during previous inspections.
r1
TR07-61 2.05-79.1 07/14/07