2025-06-30_PERMIT FILE - C1981019A ‎(2)‎

• Permit No: C1981019A
• IBM Index Class Name: Permit File
• Doc Date: 6/30/2025
• Doc Name: Performance Standards
• Section_Exhibit Name: Volume 15 Rule 4
• Media Type: D
• Archive: Yes

RULE 4 PERFORMANCE STANDARDS
nutritional value of both plant communities targeted for establishment on reclaimed lands in the Collom
expansion area should be enhanced as compared to pre-mining condition based especially on increased
forage availability and diversity(for both livestock and wildlife species).
To date, reclamation efforts at the existing operation have proven successful. Herds of deer and elk are
regularly seen grazing on the reclaimed areas. Rodent and small game populations have reestablished on
the reclaimed areas providing a readily available food source for local raptor populations and other
predators. Columbian sharp-tailed grouse also use reclaimed grasslands.
4.19 PROTECTION OF UNDERGROUND MINING
Colowyo will conduct no coal mining closer than 500 feet to any point of either an active or abandoned
underground mine. Underground coal mines have been operated in the past as discussed in Section
2.04.4, but their locations were on the-northern side of Streeter Draw well over 500 feet from present
Colowyo mining.
The surface mining activities of Colowyo have been designed so as not to endanger any present or future
operations of either surface or underground mining operations. As discussed in Section 2.05.3, Colowyo
has engineered its mining plan to maximize recovery of coal by current economical surface mining
methods.
4.20 SUBSIDENCE CONTROL
Colowyo is conducting a surface coal mining operation. Therefore, the requirements of 4.20 are not
applicable to the Colowyo operation.
4.21 COAL EXPLORATION
All coal exploration activities within the Collom permit revision area will be completed in accordance
with the requirements and procedures outlined in the Volume 1.
4.22 CONCURRENT SURFACE AND UNDERGROUND MINING
Colowyo does not plan to have concurrent surface or underground mining activities; therefore, the
requirements of this Section are not applicable to this permit application.
4.23 AUGER AND HIGHWALL MINING
4.23.1 Scope
Highwall mining allows for the recovery of additional coal resources beyond the final pit highwalls and
endwalls. Colowyo's has previously effectively highwall mined in the East, Section 16, West, and South
Taylor Pits in the past. Colowyo will utizilied the vast experience gained from previous highwall mining
and implement a highwall mining plan in the Collom Pit. Please see Section 2.06.9 and Map 23B for the
seams and areas planned to be highwall mined.
From a surface mining perspective, the Collom Pit delineates the maximum recoverable coal resources
permitted by this mining permit for Colowyo to mine. Highwall mining in the Collom Pit will allow for
for maximum recovery in accordance with Rule 4.23.2(1). Please refer to Sections 2.06.9 in Volume 1
for additional discussion regarding the removal of coal using highwall mining methods.
Collom—Rule 4,Page 35 Revision Date: 11/20/2019
Revision No.: TR-134