_INSPECTION - C1982057 ‎(50)‎

• Permit No: C1982057
• IBM Index Class Name: INSPECTION
• Doc Name: Inspection Report
• From: DRMS
• To: Seneca Coal Company
• Inspection Date: 9/21/2010
• Email Name: JRS
• Email Name: SB1
• Media Type: D
• Archive: No

September 21,2010 C-1982-057/Seneca II-W Mine JRS Lz��
location for PM-3A is shifted approximately 40 feet to the south, due to the change in alignment of channel PM-3
in that area. The lower 659 feet of the as-built channel generally follows the designed flow path. The length of
the as-built channel is approximately 790 feet shorter than the designed length. The as-built channel PM-3A
basically stops at the shrub exclosure while the designed channel goes up the slope almost to the east edge of the
disturbance boundary. There was erosion in the entire length of channel PM-3A. There was also under-cutting of
the TRM in places. The as-built profile for channel PM-3A was between 3 and 9 feet higher than the design
profile. Despite these elevation changes,the grades of the as-built profile generally matched the grades of the
designed channel and were functioning well. Although the as-built channel was shorter than the designed channel,
the area above the as-built channel was well vegetated and stable,with no erosional problems noted. Channel PM-
3A was stable and appeared to be functioning as designed. All of the flow from precipitation and runoff was
contained in the channel.
-Channel PM-6 runs on the north side of the Seneca II-W South area, south of channel PM-3A,along an
undisturbed area(north of this undisturbed area). Channel PM-6 flows into channel PM-2B at approximately
station 8+06, on the Division's profile. The upper half of the as-built channel is approximately 30 feet farther
south than the designed location. The as-built location for the lower portion of the channel PM-6 intercepts
channel PM-2A approximately 500 feet farther up the slope than the designed channel(and enters at a right-angle
as opposed to flowing into channel PM-2A at a more acute angle). The entire length of the channel had riprap and
vegetation and no erosion was noted. Based on the location changes for the as-built channel PM-6 noted above,
the as-built channel profile differs from the designed channel profile. The as-built elevations are between 14 and
50 feet higher than the design elevations. The as-built channel does not appear to be steeper than the designed
profile, although the location of the steep grades has changed. Although channel PM-6 has been changed
significantly, including the location where it intercepts channel PM-2B, it is stable and well vegetated. There were
no erosional problems in the channel and none were seen at the intercept location with channel PM-2B. All of the
flow from precipitation and runoff was contained in channel PM-6.
-Channel PM-4 is a riprapped channel in the northeast edge of the south extension area and flows into Pond 015.
The channel is designed as a trapezoidal ditch, with a bottom width of 3 feet and an overall depth of 0.6 feet and a
lining of vegetation. The as-built channel has a bottom width of 6 feet, an overall depth of approximately 2 feet
and is lined with riprap(with grass growing up into the riprap). The channel flows at an approximate slope of
27%,as compared to an average design slope of 22%. There is minor scouring in the lower section of the channel,
which will need some maintenance work. This lower portion of the channel may be a good place for TRM.
Although the average grade of the as-built channel is steeper than the design, it did not appear to be a problem.
Overall,channel PM-4 was stable and appeared to be functioning as designed.
-Channel PM-4A is a channel in the northeast edge of the south extension and flows into channel PM-4. The
channel is designed as a trapezoidal ditch with a bottom width of 3 feet, an overall flow depth of 0.65 feet and a
lining of vegetation. The as-built channel is a"V"ditch with a top width of 12 feet an overall depth of 12-18
inches and a lining of riprap. The V ditch has a cross-sectional area of 9 square feet while the designed trapezoidal
ditch has a cross-sectional area of 3.2 square feet, so the as-built ditch has a larger capacity for the designed flow.
The ditch flows at an approximate slope of 25%,as compared to an average design slope of 18%. Despite the
differences between the design and the as-built,the ditch was stable and no erosional problems were noted.
-Channel PM-4B is a channel in the northeast edge of the south extension and flows into channel PM-4A. The
channel is designed as a trapezoidal ditch, with a bottom width of 3 feet and an overall depth of 0.6 feet and a
lining of vegetation. The as-built channel has a bottom width of 6 feet and an overall depth of approximately 18
inches. The channel flows at an approximate slope of 26%,as compared to an average design slope of 22%. The
ditch was stable and no erosional problems were noted.
Number of Partial Inspection this Fiscal Year: 3
Number of Complete Inspections this Fiscal Year: 2
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