REV00707

• Permit No: C1982056
• IBM Index Class Name: Revision
• Doc Date: 5/25/2000
• Doc Name: FOIDEL CREEK MINE C-82-056 ADEQUACY LETTER NO 3
• From: DMG
• To: TWENTYMILE COAL CO
• Type & Sequence: PR5
• Media Type: D
• Archive: No

• iii iiiiiiiiiiiuiii •
999
STATE OF COLORADO
DIVISION OF MINERALS AND GEOLOGY
Depanment of Natural Resources
131 3 Sherman 51.. Room ? 1 5
Denver, Colorado 80203
Phone [phone]'
FAti: 13031 83?-8106
May 25, 2000
Mr. Rick Mills
Twentymile Coal Company
29515 Routt County Road No. 27
Oak Creek, CO 80467
Re: Foidel Creek Mine, C-82-056, PR-O5, Adequacy letter No. 3
Dear Mr. Mills:
~~
DIVISION OF
MINERALS
GEOLOGY
RECLAMATION
MINING•SAFETY
ell ovens
Governor
GregE Watcher
Execulne Duenor
M¢hael 8. Long
Division D~reaor
The Division has reviewed Twentymile Coal Company's adequacy response submittal dated May 15, 2000.
Twentymile Coal Company's submitted the additional information is response to the Division's May 2, 2000
adequacy letter. The Division's comments regarding Twentymile Coal Company's responses follow:
1. This item has been adequately addressed.
3. Twentymile Coal Company faxed revised pages 2.05-2 and 2.05-2.1 on May 16, 2000. Once the "hatd~opy"
pages are received by the Division, this item will be adequately resolved.
8. Twentymile Coal Company submitted page 2.05-132 (rev. 5/03/00). The revised page addresses the Division's
concern.
11. Twentymile Coal Company submitted pages 16-20 for incorporation into Exhibit 4e-10. Twentytmmile Coal
Company's response addresses the Division's adequacy concern.
14. Twentymile Coal Company made the appropriate changes to page 2.05-181.5 (rev. 5/03/00). This item has
been adequately addressed.
18. This item has not been adequately addressed.
The Division believes that the amount of subsidence predicted for the eastern four thousand feet of Northern
Mining District (NMD) Panel 12 Right may have been underestimated. This is the portion of the NMD where
undemmining of Routt County Road 33, Foidel Creel:, a county road culvert, and an outcrop of the Twentymile
Sandstone will occur.
Figure 2 of TCC's Exhibit 4e-3 depicts a maximum subsidence deflection of 62 inches over Panel 12 Right. This
figure assumes Panel 12 Right will be 1000 feet wide, assumes the overburden over Panel 12 Right will be 1100
feet thick, and reflects the influence of Panel 13 Right.
Figure 3 of TCC's Exhibit 4e-3 depicts a maximum subsidence deflection of 56 inches over Panel 12 Right. This