2015-10-06_PERMIT FILE - C1981019A ‎(3)‎

• Permit No: C1981019A
• IBM Index Class Name: Permit File
• Doc Date: 10/6/2015
• Doc Name: Performance Standards
• Section_Exhibit Name: Volume 15 Rule 4
• Media Type: D
• Archive: Yes

RULE 4 PERFORMANCE STANDARDS
The surface mining activities at Colowyo have been planned and will be conducted to minimize changes
in the prevailing hydrologic balance, in both the permit and adjacent areas, and to prevent long term
adverse changes in the balance that might result from the activities.
As a preliminary step in minimizing adverse changes, hydrologic baseline information has been collected,
compiled and analyzed. The baseline monitoring programs are outlined in Section 2.04.7. This data
provides detailed information on quality and quantity of surface water, drainage patterns, and geology.
The description of the current hydrologic monitoring program is included in the following pages and
results of the current monitoring program are included in the Annual Reports for 1983 through the
present. In addition, Sections 2.05.4 and 2.05.5 detail the specific mining and reclamation techniques
which Colowyo will implement to minimize changes to the hydrologic balance.
The post -mining land use as described in Section 2.05.5 will be rangeland. Changes in the hydrologic
balance will be minimized so that the post -mining land use will not be adversely affected.
Water quality standards and effluent limitations at the existing mining operation are regulated by the U. S.
Environmental Protection Agency (EPA) and the Colorado Department of Public Health and Environment
under the terms of an NPDES Permit, and by the Coal Regulations of the Colorado Mined Land
Reclamation Board. The applicable effluent limitations will be met by using treatment methods that will
include contemporaneous revegetation, minimizing disturbed areas, sediment retention, use of contour
furrows, sediment ponds and, if necessary, strategically placed energy dissipaters, such as riprap, check
dams, mulches, filters and dugouts. Water quality control measures are discussed in detail under Section
2.05.4 and 2.05.6.
Where practicable, diversion methods will be used to change the flow of water from undisturbed areas so
as to bypass the disturbed areas rather than use treatment facilities. The principal technique to be used for
this purpose will be diversion ditches. These diversion ditches are shown on the figures in Exhibit 7, Item
23, Pare E and discussed in detail under Section 2.05.6. Their design is specified in Exhibit 7, Item 23,
Part E.
No acid-forming materials are present in the area to be mined which would require selective placement
and sealing of overburden (Exhibit 6). The chemical characteristics of the overburden are presented under
Section 2.04.6. The overburden sampling program is presented under Section 2.05. Results of the current
overburden sampling program are presented in the Annual Reclamation and Hydrology Reports beginning
in 1983 to the present.
As discussed in Section 2.05.4, Colowyo will use various surface manipulation techniques on the topsoil
after its redistribution as one method to prevent excessive wind or water erosion.
No special treatment of coal processing waste is necessary since none will be produced. See Section 4.10
and 4.11.
Colowyo plans to have all surface runoff from the disturbed areas pass through sedimentation ponds.
Sedimentation ponds are discussed in detail under Section 4.05.6, and their locations are shown
graphically on the structure and facilities map (Map 22B) and in Exhibit 7, Item 26.
Colowyo employs various methods to manage water that periodically collects internal to the mining
operation and does not reach sedimentation ponds. Various sumps, ditches, pumps, hoses and pipes, etc.
will be employed to control water within pits and/or route water between pits. The ultimate destination of
such water will be for operational use (i.e. dust control), evaporation, or seepage into the backfilled spoil
areas.
Collom — Rule 4, Page 4 Revision Date: 9/28/11
Revision No.: PR -03