PERMFILE57994

• Permit No: C1980007
• IBM Index Class Name: Permit File
• Doc Date: 12/11/2001
• Section_Exhibit Name: Exhibit 16 Assessment of Roof Conditions & Cracks
• Media Type: D
• Archive: No

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~;~F//~~G~~,p DEPARTMENT OF NATURAL RESOURCES urn
F~ .s~'rt4 9p David N. Getches, Executive Director
~~ ;. ~ MINED LAND RECLAMATION DIVISION ~t•~.
• • DAVID C. SMELTON, Dlr~otor I-r~
•'ra~e' ,
Rrtna~o D Umm
Governor
September 9, 1983
T0: Bob Liddle
FROM: Jiin Pendleton
RE: Response of W Elk al Company, Inc. to Inspection Comments
Regarding "R s" at the Mt. Gunnison No. 1 Mine
Pursuant to your request, I have reviewed West Elk Coal Company's (ARCO's)
August 30, 1983 submittal. This submittal, prepared by John L. Ellenberger,
Senior Geologist for West Elk Coal Company, is the second response to my
concerns regarding the "roof crackiny" observed at the Mt. Gunnison No. 1
underyround coal mine.
In his first response, dated May 5, 1983, Mr. Ellenberger presented a very
ortef description of a postulated formation mechanism for the observed roof
• cracking. Subsequently, I requested an expanded description of the potential
formation mechanism. Mr. Ellenberger's second response presents an expanded
description of the postulated formation mechanism. The submittal includes
sketches of the phases of fracture development related to deposition, channel
erosion, material compaction and regional deformation of the F Seam and its
• overburden at the Mt. Gunnison No. 1 mine site. The scenario presented is
plausible and compatible with the geoloyical artifacts observed in the floor,
coal seam and roof strata at the mine.
In my opinion, the operator has now adequately responded to my concerns
reyarding the "roof cracking phenomena" as originally presented in my
inspection report of August 31, 1982. Continuance of the monitoring of the
observed fractures, being performed by West Elk Coal Company, should assure
early detection of any problem which might develop. No movement has been
detected to date on any of the fractures being monitored at the Mt. Gunnison
No. 1 Mine.
Finally, i will consider this information and the possible consequences of the
"roof cracking" during the completion of our mid-term review of the h1t.
Gunnison No. 1 Mine, scheduled for the not-too-distant future. There nay be
some additional deign considerations involving mine configuration which will
require design resolution at that time.
/int
• cc: Ed Bischoff
Doc. No. 5429
423 Centennial Building, 1313 Sherman Street Denver, Colorado 80203 Tel. [phone]