REV06777

• Permit No: C1981033
• IBM Index Class Name: Revision
• Doc Date: 7/22/1982
• Doc Name: REQUESTED REVISION OF UNDERGROUND DEVELOPMENT WASTE DISPOSAL AT THE MT GUNNISON 1 MINE
• From: MLR
• To: RICH DOMINQUE
• Type & Sequence: MR1
• Media Type: D
• Archive: No

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STATE OF COLOPApO 4iCHnnn n i~ nnv^~^
DEPARTMENT OF NATURAL RESOURCES
D. Monte Pascoe, Executive Des ector
M11VED LAND RECLAI~IA'TION
423 Centennial Building, 1313 Sherman Street
Denver, Colorado 80203 Tel. [phone]
David C. Shelton
July 22, 1982 Director
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TO: Rich Domingue
FROM: Jim Pendleton '~cc-\ ~,..XQ.~<y~~
RE: Requested Revision ofj(Inderground Development Waste Disposal
at the Mt. ~nnison No. 1 Mine
ARCO Coal Company has expressed a desire to deposit underground development
waste from the Fit. Gunnison No. I Mine within the backfill for the portals
of the adjoining Bear No. 2 Ffine. ARCO has encountered an unanticipated
seam pinch within the No, 1 and No. 2 portals at the Mt. Gunnison No. 1
Mine, which has resulted in the development of approximately 5,000 cubic
yards of waste material. This waste is currently being temporarily stock-
piled adjacent to the portals and within the approved site of the initial
waste rock pile. ARCO desires to reserve capacity within the approved
initial waste pile for later use. As an alternative to placing waste within
the approved initial waste pile, ARCO desires to utilize available storage
capacity within the Bear No. 2 portal bench., which is currently undergoing
reclamation.
Bear Coal Company, as a portion of its approved permit application for the
Bear No. 1 and No. 2 Mines, was required to complete a stability analysis
of their proposed backfill configuration for the Bear No. 2 Mine portal
bench face-up. This analysis considered several alternative configurations
for the reclamation of the affected portal cut. Several configurations
were demonstrated to satisfy the requirements of the permanent program
regulations within this "steep slope" segment .of the mine's permitted area.
On Thursday, July 15, I examined the waste material stockpiled at the
P1t. Gunnison No. 1 Afine and the Bear No. 2 Mine's portal area. That waste
material appears to consist of floor and roof claystone contaminated with
coal and siltstone. As such, 'it is not significantly different from the
spoil which comprises the Bear No. 2 Mine's portal bench, as well as much
of the underground development waste material obvious throughout the Bear
Ffi ne's surface facilities. It is these materials, collected from throughout
the surface facility area, which were projected to comprise the backfill
of the Bear No. 2 Mine's portal face-up'. Therefore, the placement of
underground development waste from the Mt. Gunnison No. 1 Afine should not
significantly decrease the strength of the materials to be utilized as
backfill for the Bear No. 2 Mine's portal area.
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