REP48888

• Permit No: C1982056
• IBM Index Class Name: Report
• Doc Date: 12/15/2004
• Doc Name: 1st Half 2004 Subsidence Report Review Letter
• From: DMG
• To: Twentymile Coal Company
• Permit Index Doc Type: Subsidence Report
• Media Type: D
• Archive: No

Review Checklist for Subsidence Monitoring Report
Mine: FOldel Creek Date this review was completed: December 15, 2004
Permit No.: C-82-056 CDMC reviewer: Byron G. Walker
Report period: 1st half 2004
Panel(s) mined during report period: 15 and 16 Right
This monitoring report covers that period of time where portions of the 15 Right and 16 Right
panels of the Northern Mining District were undermined [see Subsidence Map First Half 2004
of the report (2004 Map)].
Monitoring requirement
(regulation citation)
Permit requirement In
compliance:
Comment
Yes / no .
PAP, pages 2.05- Previous subsidence monitoring
184.10 and 2.05-191.4. has demonstrated that subsidence
2.05.6(6)(c)(i)(A) The requirement of this predictions were conservative and
Monuments shall be rule has been limited to provided acceptable descriptions
installed and surveyed monitoring of selected
Yes of expected subsidence. This
prior to the structures and report indicates that maximum
commencement of renewable resource subsidence reports were
mining lands. See Rule approximately 15% more than
2.05.6(6)(c)(i)(C) anticipated, but overall,
below. correlation was ood.
2.05.6(6)(c)(i)(B) pAP, page 2.05-184.10.
Monuments shall be The requirement of this
situated to appropriately rule has been limited to Total surface strain was
monitor ground surface monitoring of selected determined by locating
movement, vertical and structures and monuments at expected points of
horizontal, within the renewable resource Yes minimum strain (over gateroads),
area proposed to be lands as for the rule maximum strain (over mid-
undermined, including above. See Rule panel), and in areas of transition.
an area to accommodate 2 05.6(6)(c)(i)(C)
the predicted angle-of- below.
draw.
2.05.6(6)(c)(i)(C) The PAP, pages 2.05-
orientation, location and 184.10 and 2.05-191.4,
and the 2004 Map.
A section of the Union Pacific
elevation of each Only those structures Yes Railroad and a section of Fish
structure within the Within the approved Creek were undermined.
permit and adjacent affected area are
urea shall be monitored. monitored.
2.05.6(6)(c)(i)(D) PAP, page 2.05-185
Monitoring of Monitoring was Monitoring of the railroad track
established monuments accomplished at least was accomplished approximately
and structures shall be quarterly, scheduled by
Yes once a week for three weeks
performed at least time mining progress. (report, page 4). The section of
quarterly, commencing As an example, Station Fish Creek was surveyed before
one month prior to the 415 (center of Panel and after undermining.
initiation of minin 16) was surveyed