APPCOR10593

• Permit No: C1981034
• IBM Index Class Name: Application Correspondence
• Doc Date: 11/23/1981
• Doc Name: RED CANYON COAL MINES AMENDED PERMIT APPLICATIONS SUBSIDENCE SECTION
• From: MLR
• To: DAN MATHEWS
• Media Type: D
• Archive: No

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MINED LAND RECLAMATION
•
STATE OF COLORADO RiC HARD D. LAMM. Govemm
DEPARTMENT OF NATURAL RESOURCES III III III III IIII III
D. Monte Pascoe, Executive Director
999
423 Centennial Building, 1313 Sherman Street
Denver, ColoradD 80203 Tel. [phone]
David C. Shelton
Direcior
i:ovember 23, 1981
TO: Dan Mathews
FROM: Jim Pendleton
RE: Red Canyon Coa Permit Application's
Subsidence Sec
Pursuant to your request I have reviewed the supplemental submittals amending
the subsidence sections of the Red Canyon Coal Mine's permit application.
Generally, the amended submission represents a significant improvement
over the original application document. However, there remain several
deficiencies within the subsidence section, one potentially major deficiency
and several minor deficiencies.
Potential Impacts Upon the Hydrologic Balance of the "Glacial Outwash
Surficial Aquifer of Ward Creek"
The Surficial aquifer of Ward Creek will be undermined by the proposed under-
ground workings of the Red Canyon No. Z and No. 2 mines. As I observed in my
earlier memos, the company encountered particularly severe roof stability
problems while driving the No. 1 west submains toward Ward Creek in the south-
west 1/4 of the northeast 1/4 of Section 11. The company informed the
Division by telephone and letter of this difficulty and requested permission
to drill 2 additional exploratory drill holes. The results of that coring
project were to be utilized to redesign the mining plan. These amendments
will have to be reflected within the amended permit application. Furthermore,
the implications of possible roof fall and subsidence upon the hydrologic
balance of the alluvial aquifer beneath Ward Creek and any overlying structures
and wells will have to be specifically discussed within that amended application.
While the company appears to have made a few minor amendments to the hydrology
and operation plan portions of the application document, it continues to fail
to straightforwardly discuss this specific problem. This discussion should
include the results of the additional coring performed, and potential impacts
of the amended mining plan upon subsidence and the hydrologic balance of the
Surficial aquifer of Ward Creek. In my opinion, absence of such a discussion
may constitute a possibly fatal flaw in the application. I suggest you
discuss this matter in detail with Roy Cox and either Jerry Zimpfer or Dave
Craig. In addition, I suspect that ward Creek may constitute an alluvial
valley floor. I also doubt that the Surficial deposits within the Ward
Creek valley are actually of glacial origin. It is much more likely that
1 fine's nded