REV88871

• Permit No: C1980007
• IBM Index Class Name: Revision
• Doc Date: 3/19/1997
• Doc Name: WEST ELK MINE MINOR REVISION MR210 SUPPLEMENTAL RESPONSE DATED 03 19, 1997 PN C-80-007
• From: DMG
• To: DAVE BERRY
• Type & Sequence: MR210
• Media Type: D
• Archive: No

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STATE OF COLORADO
DIVISION OF MINERALS AND GEOLOGY
Department of Natural Resources
1313 Sherman Sr., Room 215
Denver, Colorado 80203
Phone: [phone]
FAX: [phone]
DATE: March 19, 1997
TO: Dave Berry \~~
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FROM: Jim Pendleton ~ (~~~\JJY'
RE: West Elk Mjne, Mi r Revision MR-210
Suppleme esponse Dated March 19, 1997
Permit No: C-80-007)
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DEPARTMENT OF
NATURAL
RESOURCE
Roy Romer
Governor
lames 5 Lochhead
Eaecueve Director
Michael B. Lang
Division Director
I have reviewed the above referenced supplemental response to our earlier adequacy
comments regarding this MR application, which you forwarded to my attention. In
response to my recommendation of installing slot track tilt meter tube in several of the
proposed holes, Mountain Coal has declined. Ms. Johnston observed that MCC prefers
to install permanent survey prisms to monitor slope movement. Further they are not
receptive to installing monitoring installations in areas slated for construction disturbance,
because they will be short lived.
The total station style reflector prisms will allow very accurate monitoring of the
installations chosen. However, they will only provide measurement of the surface point
upon which they are installed. Tilt-meter or slot-track style installations allow the
determination of differential movement throughout the depth of the installation. With
consideration, I believe locations could be chosen which would allow the monitoring of
existing meta-stable slopes within Sylvester Gulch during the early construction.
Locations such as MCCPZ97-2 and MCCPZ97-4, which appear to be adjacent to existing
mapped unstable landforms, would appear to be good candidates for tiltmeter monitoring.
These installations could provide useful information if they survive several months after
initial excavation for the enlarged Sylvester Gulch Access Road.
The installation of a selection of different monitoring facilities will allow the collection of
varying geotechnical and ground water data with which to assist MCC in detecting any
slope adjustment which might occur in response to their projected construction. The
information collected at early construction sites could assist in design of future
construction projects. The data collected might justify less stringent design parameters,
conceivably resulting in reduced construction costs.