PERMFILE128862

• Permit No: C1980007
• IBM Index Class Name: Revision
• Doc Date: 6/13/2005
• Doc Name: 2nd Adequacy Response Letter June 2005
• Type & Sequence: PR10
• Media Type: D
• Archive: No

~~(I~AIN (OAL
OMPAIIY~
~ COMPANYLLC. w.~F,~M,..
West Elk Mine
~
A Subsidiary of Arch Western Resources, LLC P O Box 591
S l74 Highway 133
Somerset, CO 81434
[phone]
Fax [phone]
that typically quickly seal once fractured These units would likely preclude the vertical movement of
water from the surface or saturated alluvium into the fractured zone above the mine gob.
Burnout Canvon Creek
Burnout Canyon Creek is located in the Huntington Creek Drainage ojEmery County, Utah and lies
entirely within the Skyline Mine Permit area. The permit area lies within the northern Wasaach
Plateau. Longwall mining undermined about 95% of the drainage. Approximately SO % of the area
undermined was subjected to two-seam extraction mining. Subsidence ojthe perennial portion of the
drainage ranged from a few feet to about 20 feet. The longwall panels were oriented in almost a
perpendicular orientation to the axis of the canyon. The gradient ojthe perennial portion of Burnout
Creek is 7.6%, similar to the Dry Creek gradient of 4.0 %.
The stream channel within Burnout Canyon lies at the base ojmoderately wide, steep slope drainage.
10 to 30 feet or more ojcolluvium and alluvium consisting of sand, silt, and clay derived entirely
from the B[ackhawk Formation generally covers the floor of the canyon. The stream channel is
generally only a few feet wide and sinuous. Signiftcant channel meanders have formed in the mid
and lower sections of the canyon. Overburden above the coal seams mined ranged from about 650
feet near the mouth ojthe canyon to 1000 feet at the head of the canyon (the majority of the two -
seam mining took place where the overburden was 800 to 1000 feet thick).
The only formation exposed in the Burnout Canyon area is the Blackhawk Formation. It consists of
interbedded sandstone, siltstones, c[aystones, mudstones and shales. Fluvial sandstone channels are
found throughout the shatigraphic section. The mineable coal seams in the Skyline Mine permi t
area occur within this formation.
The Monti-Casa! National Forest and Skyline Mine conducted a joint study conducted by to
determine the impacts ojsubsidence on the Burnout Canyon Creek. The study was initiated in 1992
and completed in 1998, though mining did continue in the drainage until late 1003. Stream
morphology data were collected from 1992 through 1997 before and during mining induce
subsidence. Flow data, collected on at least a monthly basis, at six locations within the main channel
began in 1992 and has continued through 2004.
The results of the channel morphology studies were reported in 1998 by the Forestry Sciences
Laboratory, Rocky Mountain Research Station, Logan, Utah to the Monti-Casa! National Forest.
The report indicated minor changes have occurred to the sheam channel as a result of changes in
pool density and number and length of riffles, but these changes were not significantly different than
those changes occurring in a nearby stream channel in an area that was not subsided Other minor
morphologic changes were noted in the stream channel but none were determined to be significant.
The most significant result of the study and post-study flow monitoring in Burnout Canyon Creek is
the conclusion there has been no discernable loss ojflow in the stream due to mining related
subsidence.
i East Fork of Box Canvon. Canvon Fuel Comoanv, LLC. Sutco Mine
The Sujco Mine, located in Central Utah on the southern Wasatch Plateau within the Monti-Casa!
and Fishlake National Forests, undermined a portion ojthe perennial East Fork of Box Canyon
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