REV106256

• Permit No: C1981019
• IBM Index Class Name: Revision
• Doc Date: 5/14/1993
• Doc Name: RESPONSE TO COLOWYOS PAR RESPONSE LETTER 5/10/93 C-81-019
• From: DMG
• To: STEVE WATHEN
• Type & Sequence: TR21
• Media Type: D
• Archive: No

• • III IIIIIIIIIIIIIIII
999
STATE OF COLORADO
DIVISION OF MINERALS AND GEOLOGY
Department o(Natural Resources
1313 Sherman SI., Koom ? 15
Denver, CO 80_'03
Phone: [phone]
FAX: [phone]'-8106
May 14, 1993
TO: eteve Wathen
FM: Bhawn Smith
Re: Response to ColoWyo's PAR response letter 5/10/93
(C-81-019)
Dear Steve:
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Roy Romer
Governor
Michael B Long
D lv ision Director
In brief, I have reviewed the report by Norwest and discussed same
with Jim Pendelton and we both agree that all concerns addressed in
your March 26, 1993 letter have been answered sufficiently.
Division concerns revolving around the hydrologic Impact,
spontaneous combustion, methane generation or shrinking of the
support webs have all been satisfied. However, the issue of
surface subsidence and mitigation still remains. Therefore, the
Division requests the following: That to provide support for the
minimal subsidence expected, that a minor line of subsidence
monuments be placed above the first dozen holes to be auger mined.
These monitors could then be used to provide additional support to
the Norwest contention that Smax would only be 0.1 inch of
deformation of the surface.
Upon surveying of these monuments, post-auger mining, if the Smax
is observed to lie within the realm of reason as purported by the
Norwest report, then further monitoring will not be necessary.
This concludes my review and recommendations.