2025-10-31_PERMIT FILE - C1981019 ‎(5)‎

• Permit No: C1981019
• IBM Index Class Name: Permit File
• Doc Date: 10/31/2025
• Section_Exhibit Name: 2.05 Operations and Reclamation Plans
• Media Type: D
• Archive: No

RULE 2 PERMITS

Rule 2 Permits 2.05-12 Revision Date: 8/6/25
Revision No.: PR-05

The planned coal production at the Colowyo operation is shown in Table 2.05-2.

Blasting

Colowyo usually engages in blasting of overburden and coal before its removal. A general
sequence for drilling and blasting of overburden and coal will proceed as follows:
(1) Establish a drill bench on the overburden.
(2) Utilize the timing model to determine the maximum number of blast holes that will ignite
in any 8-millisecond period, this will determine the size of the blast pattern and the
maximum amount of explosive to ignite at any 8 ms time period.
(3) Compare this poundage of explosives to the “scale distance formula” result. If the blast
design exceeds the criterion of the “scale distance formula,” then we will revise the
design until compliance is met.
(4) Blast pattern design will then be sent to the field for implementation by the blasters.
(5) Drill blasting pattern.
(6) Load drill holes with explosives.
(7) Blast reports will then be recorded to meet the criteria noted in Rule 4.08.5 (1) thru (18)
for surface coal mining operations.
(8) Blast overburden.
(9) Remove blasted overburden with shovel, front-end loader, or dragline.
(10) Clean coal seam.
(11) Drill blasting pattern.
(12) Load drill holes with explosives.
(13) Blast Coal Seam
(14) Remove blasted coal with front-end loaders.

Colowyo will comply with all applicable state and federal laws in its use of explosives.
Experienced, trained, certified and competent persons conduct all blasting operations.

Because of the inherent complexities of the Colowyo mining operation, the surface blasting
program has been developed to conform with a variety of coal seams and the diverse overburden
handling techniques. The coal blasting will vary from coal seam to coal seam because of the
different thickness encountered. Three general types of overburden blasting will be required: one
for blasting overburden, one for the pre-splitting of overburden to provide for safer highwalls and
one for blasting coal.

Approximate blasting patterns for coal and overburden are shown in Table 2.05-4, Blasting
Parameters – Overburden (Typical); Table 2.05-5 Blasting parameters – Overburden pre-Split Shot
(Typical) and Table 2.05-6, Blasting Parameters – Coal (Typical).

Colowyo will conduct a timing analysis through various methods for each overburden shot
utilizing the down hole delay timing, hole-to-hole delay timing, and row to row timing as
applicable to verify the maximum number of holes and thereby pounds of explosive detonated per
8 ms time period. This analysis can be conducted by hand or with computer software that predicts