REV99369

• Permit No: C1981019
• IBM Index Class Name: Revision
• Doc Date: 3/14/1994
• Doc Name: PN C-81-019 TR 26 REDUCTION OF ENVIRONMENTAL MONITORING REQUIREMENTS
• From: COLOWYO COAL CO
• To: DMG
• Type & Sequence: TR26
• Media Type: D
• Archive: No

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COAL
COMPANY
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~:~~AR 141994
5731 State Highway 13
Meeker, Colorado 87647
[phone]
March 10, 1994
Me. Janet Binne .. Ca Pn~,~~rC'.<: C L~;;~'CP%~
Environmental Protection Specialist Cf, ~~~,.'
Colorado Division of Minerals and Geology
215 Centennial Building
1313 Sherman Street
Denver, Colorado 80203
RE: Permit C-81-019, T.R.
Monitoring Requirements
26, Reduction of Environmental
Dear Me. Binne:
The following information is submitted in response to the Division's
correspondence of February 17, 1994 regarding the referenced technical revision
request.
Streeter Fill Survey Monitoring;
Colowyo respectfully questions the Division's new found concern
regarding the appearance of a water level rise within the fill. The
Division's concern is manifested by a request for an additional
stipulation calling for prompt notification of the Division should
an "abnormal" 2 foot rise of the water level of the now dry
piezometer well occur. At a time when we are proposing some relief
in monitoring requirements supported by 12 years of environmental
data collection and analysis this commitment would appear
particularly out of place and contrary to the data collected to
date.
Moreover, Colowyo respectfully questions the imposition of a
monitoring stipulation more onerous than the monitoring requirements
currently in effect for the fill.
The Division's request appears to be more suited to new excess spoil
fill construction where it is predicted that the existence of a
perched water table might occur based upon the knowledge obtained
from the baseline data provided by the operator, concerns expressed
by geotechnical engineer's reviews and lacking the benefit of a
historical piezometer well database record after construction.
With respect to the conditions found within Streeter fill the
piezometer well ie dry and the development of a future water table
appears to be highly unlikely (as was predicted). Moreover, should
a water table develop the Division will recall that the August 15,
1979 CTL/Thompson report provided results of an analysis designed to
determine the effect of various water table conditions. The report
states "it should be noted that for a condition where the angle of
internal friction of the colluvium is 26 degrees and the water is
more than 100 feet above the bedrock the slip circles are
essentially the same and show a relatively small failure at the toe
of the slope.(pp.16-17)" In effect it was predicted that the fill
would meet the stability requirements even if (in the highly
unlikely event) a 100 foot water table developed above bedrock. In
light of the CTL/Thompson report and the 12 years of monitoring
data, the Division's proposal that a piezometer well water level