2013-09-27_REPORT - C1980007 ‎(4)‎

• Permit No: C1980007
• IBM Index Class Name: REPORT
• Doc Date: 9/27/2013
• Doc Name: Spring 2013 Subsidence Monitoring Report
• From: Wright Water Engineers, Inc
• To: DRMS
• Permit Index Doc Type: Subsidence Report
• Email Name: JRS
• Email Name: DIH
• Media Type: D
• Archive: No

Spring 2013 Subsidence and Geologic Field Observations
South of Divide and Dry Fork Mining Areas (E -Seam)
Figure 4. Spring 2013 image looking south along
the northwestern edge of the MDW E4 -8 pad at
two sub - parallel subsidence cracks. These
cracks coincide with the greatest fill depth of the
pad but do not exhibit the characteristic parallel
orientation to the edge of the pad as is expected
with differential settlement.
Figure 5. Spring 2013 view looking south along
the western edge of the MDW E4 -8 pad at a
subsidence crack located along the loose berm
material at the edge of the pad.
A comparison between photographs obtained in fall 2009 and spring 2010 revealed that one of the
rock columns had collapsed shortly after mining beneath the area. Photographs obtained regularly
since spring 2010 of this same rock outcrop area (including spring 2013) reveal that there has been
no additional rockfall or column collapse. No comparative photographs are therefore presented in
this report.
4.5 Traverse D -D'
This is the first of three named traverses that originate from Traverse C -C'. This traverse (formerly
Traverse O -O') begins at the USFS gate immediately east of Deep Creek along Dry Fork Road (C'
of Traverse C -C') and proceeds northward to the eastern end of E -seam Longwall Panel E3 (see
Maps 1 and 2). This traverse leads to five MDWs on two separate pads (E3 -68, E3 -72, E3 -75, E3-
76, and E3 -78).
831 - 032.795 Wright Water Engineers, Inc. Page 14
September 2013
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Figure 4. Spring 2013 image looking south along
the northwestern edge of the MDW E4 -8 pad at
two sub - parallel subsidence cracks. These
cracks coincide with the greatest fill depth of the
pad but do not exhibit the characteristic parallel
orientation to the edge of the pad as is expected
with differential settlement.
Figure 5. Spring 2013 view looking south along
the western edge of the MDW E4 -8 pad at a
subsidence crack located along the loose berm
material at the edge of the pad.
A comparison between photographs obtained in fall 2009 and spring 2010 revealed that one of the
rock columns had collapsed shortly after mining beneath the area. Photographs obtained regularly
since spring 2010 of this same rock outcrop area (including spring 2013) reveal that there has been
no additional rockfall or column collapse. No comparative photographs are therefore presented in
this report.
4.5 Traverse D -D'
This is the first of three named traverses that originate from Traverse C -C'. This traverse (formerly
Traverse O -O') begins at the USFS gate immediately east of Deep Creek along Dry Fork Road (C'
of Traverse C -C') and proceeds northward to the eastern end of E -seam Longwall Panel E3 (see
Maps 1 and 2). This traverse leads to five MDWs on two separate pads (E3 -68, E3 -72, E3 -75, E3-
76, and E3 -78).
831 - 032.795 Wright Water Engineers, Inc. Page 14
September 2013