1990-03-29_REVISION - C1981035

• Permit No: C1981035
• IBM Index Class Name: REVISION
• Doc Date: 3/29/1990
• Doc Name: Review of Draft Adequacy Comment Letter
• From: Jim Pendleton
• To: Dan Mathews
• Type & Sequence: PR2
• Media Type: D
• Archive: No

STATE OF COLORADO
MINED LAND RECLAMATION DIVISION
Department of Natural Resources C)T co 9
1313 Sherman St., Room 215
Denver,CO 80203 { „ /*
303 866-3567 . �i.
FAX: [phone] '1876'
Roy Romer,
Governor
Fred R.Banta,
Division Director
DATE: March 29, 1990
TO: Dan Mathews
FROM: Jim Pendleton 'r
RE: Review o raft Ad acy Comment Letter - King Coal #PR-02
In accordance with your request I have reviewed your draft adequacy letter for
Permit Revision #PR-02 to the National King Coal underground coal mine. In my
opinion you have correctly ascertained each of the apparent geotechnical
adequacy concerns contained within the application for revision.
Coal Mine Waste:
They should discuss the projected waste volume to be produced, in order to
ascertain whether it will be properly disposed. If they intend to backstow
the waste, they must provide us with an MSHA approved backstowing plan.
Otherwise they will need to prepare a proper coal mine waste disposal plan, as
you referenced.
Mine Subsidence:
The permit is inconsistent, but does mention the development of subsidence
cracks adjoining section 3rd East on page 21 . Obviously the development of
such cracks could represent a significant hydrologic interruption to both the
surface and ground water hydrology of the Pine Gulch drainage. The operator
first needs to resolve the drainage's status as an Alluvial Valley Floor.
Without a discussion of the probable hydrologic consequences, it is difficult
to ascertain the probable effects.
Further, the operator would have us believe that the subsidence cracking above
3rd East panel can be simply avoided by realigning the workings to obliquely
intersect the cleat direction. This fact will have to be demonstrated
somewhere outside areas which could potentially affect a drainage before they
could be allowed to mine beneath the Pine Gulch drainage. Failing such a
demonstration, extraction beneath areas which could materially damage the
drainage must be restricted to development only, which normally recovers less
than 35% of the in-place coal .
cc: Jim Stevens