REP23653

• Permit No: C1982056
• IBM Index Class Name: Report
• Doc Date: 11/1/2005
• Doc Name: 1st half 2005 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: Foidel Creek Date this review was completed: NOV¢mher 1, 200$
Permit No.: C-1982-056 CDMG reviewer: Byron G. Walker
Report period: 1st half 2005
Panel(s) mined during report period: 17 Right
This monitoring report covers that period of time where portions of the 17 Right panel of the
Northern Mining District was undermined [see report, Foidel Creek Mine -Permit No. C-82-
056 First Half-Half 2005 Subsidence Report, August 8, 2005, and Table 4, Exhibit 7e-8, of
the Permit Application Package (PAP)].
Monitoring requirement
(regulation citation)
Permi[ requirement In
compliance:
Comment
Yes/no?
PAP, pages 2.05-
184.10and 2.05-191.4. Appropriate surveys had been
2.05.6(6)(c)(i)(A) The requirement of this
Previous subsidence
made
Monuments shall be rule has been limited to .
monitoring has demonstrated that
installed and surveyed monitoring of selected Yes subsidence predictions were
prior to the structures and conservative and provided
commencement of renewable resource acceptable descriptions of
mining lands. See Rule expected subsidence.
2.05.6(6)(c)(i)(C)
below.
2.05.6(6)(c)(i)(B) pAP, page 2.05-184.10. Total surface strain was
Monuments shall be The requirement of this determined by locating
situated to appropriately rule has been limited to monuments at expected points of
monitor ground surface monitoring of selected minimum strain (over gateroads),
movement, vertical and structures and maximum strain (over mid-
horizontal, within the renewable resource Yes panel), and in areas of transition.
area proposed to be lands as for the rule In this report, subsidence on rail
undermined, including above. See Rule monuments was tabulated to
an area to accommodate 2 05.6(6)(c)(i)(C) indicted total subsidence of the
the predicted angle-of- below. rail line (R-stations).
draw.
2.05.6(6)(c)(i)(C) The PAP, pages 2.05-
orientation
location and 184.10 and 2.05-191.4,
,
elevation of each and the 2005 Map. A section of the Union Pacific
structure within the Only those structures Yes Railroad and a section of Fish
permit and adjacent Within the approved Creek were undermined. The
area shall be monitored affected area are
. monitored.
2.05.6(6)(c)(i)(D) PAP, page 2.05-185 Visual inspections were
Monitoring of Monitoring was conducted daily when appropriate
established monuments accomplished at least (see page 1 of the report). Daily
and structures shall be quarterly, scheduled by Yes surveys were reported. The
performed at least time mining progress. section of Fish Creek was
quarterly, commencing As an example, Station surveyed before and after
one month prior to the 402 (center of Panel underminin .