2023-01-05_REVISION - C1981019 ‎(13)‎

• Permit No: C1981019
• IBM Index Class Name: Revision
• Doc Date: 1/5/2023
• Doc Name Note: & Findings
• Doc Name: Notice of Proposed Decision
• From: DRMS
• To: Chris Gilbreath Tri-State Generation and Transmission Association
• Type & Sequence: RN8
• Email Name: ZTT
• Email Name: AME
• Media Type: D
• Archive: No

The Mine has no coal processing waste banks.
IX. Coal Mine Waste- Rule 4.11
No water is used in the coal processing operation, except for dust suppression, and no coal
processing waste is produced.
Non-coal waste is placed in the backfill of pits in a manner consistent with the requirements of
Rule 4.11.4.
X. Slides and Damage- Rule 4.12
The Permit is found to be in compliance with Rule 4.12. Because of the mining technique used,
natural barriers are not necessary. Slides have occurred within the permit boundary; however,
none have had an adverse effect on public property, health, safety, or the environment. Slides
have been reclaimed as appropriate.
XI. Contemporaneous Reclamation - Rule 4.13
The Permit is in compliance with Rule 4.13. Reclamation occurs as contemporaneously as
practicable with mining operations, as further discussed in Section XII below.
XII. Backfilling and Grading- Rule 4.14
The Permit is in compliance with Rule 4.14.
A. Operations and Reclamation Plans
Colowyo's operations plan is found in Section 2.05.3 of the PAP (Volume 1 for the East Pit,
West Pit, Section 16 Pit, Facilities Area and Gossard Loadout; Volume 12 for South Taylor Pit;
Volume 15 for Collom Pit). Maps 23, 23A, and 23B of the PAP contain the mine plan. Section
2.05.4 of the PAP contains the reclamation plan, and Section 4.14 contains the performance
standards for backfilling and grading.
During the approval process of Permit Revision No. 2, the Division added Stipulation 2
regarding the Lower Wilson mining area to the operations and reclamation plan at the Mine.
B. Contemporaneous Reclamation
Section 4.13 of the PAP contains information on contemporaneous reclamation for Colowyo's
multi-seam operations, with additional information found in Sections 2.05.4 and 4.14.
Backfilling and grading cannot begin with multi-seam operations until the lowest seams are
mined. Therefore, backfilling and grading cannot be completed within 180 days of the removal
Proposed Decision and Findings of Compliance January 5,2023
Permit Renewal No. 8 Page 148