GENERAL32613

• Permit No: C1981025
• IBM Index Class Name: General Documents
• Doc Date: 7/14/1983
• Doc Name: PROPOSED DECISION AND FINDINGS OF COMPLIANCE
• Permit Index Doc Type: FINDINGS
• Media Type: D
• Archive: No

-50-
The applicant proposes to implement a subsidence control plan to mitigate
impact upon the inventoried structures and renewable resource lands
within the permit area. Witfrln the areas delineated on Maps A and B
within Exhibit 4-H, the applicant proposes to limit extraction to
development entries with limited cross-cuts. The proposed development
entry configurations limit coal extraction to a maximum of approximately
34X of the in-place coal within the boundaries of the developed entry
sets. This limited extraction plan will be implemented beneath the
valleys of Middle and North Thompson Creeks, as well as their associated
alluvial deposits. County Road 108 and all potentially affected mine
surface facilities will also be protected through utilization of the
limited extraction control plan. The areas to be extracted utilizing the
limited extraction plan are delineated to reflect an angle of draw of
35o in the up-dip direction and 45o in the down-dip direction from
the proposed underground workings.
The applicant proposes a subsidence monitoring program to verify the
pro~ectlons of anticipated subsidence presented within the permit
application. Visual monitoring will be conducted periodically in order
to observe surface crackiny occurrence and configuration changes through
time. Hydrologic monitoring will be conducted to observe surface water
infiltration and aquifer performance chanyes through time. Leveling
points will be installed in connection with the surface facilities of the
1ne. Leveling point surveying monuments will also be installed above any
limited extraction entries within tire areas designated for control plan
implementation on Maps A and 6 of Exhibit 4-H. The applicant will also
utilize the monitoring results of an on-goiny U.S. Department of Energy
funded subsidence monitoriny program nou beiny conducted above the
workings of the No. 1 North Thomppon Creek Mine.
In order for the Division to deem the subsidence control plan to be fr
compliance with the regulatory requirements, the Division deems it
appropriate to impose the following subsidence monitoring stipulation:
Stipulation No. 9
THE DIVISION DIRECTS SNOWMASS COAL COMPANY TO INSTALL SUBSIDENCE
MONUMENTATION, AS DESCRIBED WITHIN EXHIBIT 4-H OF THE PERMIT
APPLICATION, ABOVE ANY UNDERGROUND WORKINGS INSTALLED WITHIN THE
LIMITED EXTRACTION AREAS INDICATED ON MAPS A AND B OF EXHIBIT 4-H.
SURFACE SUBSIDENCE MONUMENTS SHALL BE INSTALLED AND SURVEYED AT
LEAST ONE MONTH PRIOR TO UNDERMINING.
With the imposition of the above stipulation, the Division finds the
subsidence evaluation, subsidence control plan and subsidence monitoring '
program to be in conformance with the requirements of this Section.
XXII. Special Categories of Mining - Rules 2.06. 4.22. 4.23. 4.26.
4.27. 4.28 and 4.29