2018-06-01_REVISION - C1980007 ‎(3)‎

• Permit No: C1980007
• IBM Index Class Name: Revision
• Doc Date: 6/1/2018
• Doc Name: Comment Forwarded To Applicant
• From: Shannon Hughes, Wild Earth Guardians
• To: DRMS
• Type & Sequence: PR15
• Email Name: LDS
• Media Type: D
• Archive: No

percent, and via ventilation exhaust shafts as VAM, in concentrations ranging from negligible to greater
than 0.3 percent in air, with a pso methane concentration of 0.131 percent for the Deer Creek shaft
(Figure 8).
Figure 8: Probability Distribution of Methane Concentration in the Deer Creek ESM Shaft
Name: Methane Concentrafion in Shaft 4 Ventilation for Four Yews
u
Lognormal Distribution
0
a
P10= 0211%
ean=0.140%
edian = 0.131
50 = 0.131 e
P90 = 0.081
Location 0.000% }: Meen 0.140% Std. rev. 0.05495 �:
pso =Median, there is a
50 percent probability
that the methane
concentration in the
Deer Creek ESM shaft
will be 0.131 percent.
Pio
= There is a 10
percent probability
that the methane
concentration in the
Deer Creek ESM shaft
will be 0.211 percent
or greater.
p90 = There is a 90
percent probability
that the methane
concentration in the
Deer Creek ESM shaft
will be 0.081 percent
or greater.
CMM Capture
The West Elk Mine regularly employs GVBs as a component of its methane ventilation program, with the
production from GVBs ranging between 12 and 71 percent of total methane liberated, and an average
contribution of 41 percent since the mine began reporting this information in 2011.
The general practice for the mine is to vent this gas to the atmosphere, occasionally transporting gas to
burners located in Sylvester Gulch to heat the air that is pumped into the mine. This is only done during
the winter months and utilizes only a very small percentage of drained gob gas. The method that the
mine uses to gather and transport the gas for this task is the same concept that is envisioned for the
capture and use projects evaluated in this study, with the exception that in this study we assume that all
available gas produced from active GVBs will be utilized or destroyed, rather than vented. Given that
methane has a global warming potential (GWP) of greater than 36 times that of COz when measured
over a 100 -year period and 87 times that of CO2 when measured over a 20 -year period, destruction of
this gas, as opposed to venting it, will have a positive impact on the local and regional environment. For
the purposes of this study, a GWP of 25 is used to calculate project emission reductions and the amount
of carbon emissions credits generated, as 25 is the value that is currently used by the carbon markets.
10
q
0.106%
0.200°% 0.306% 0.400%
pso =Median, there is a
50 percent probability
that the methane
concentration in the
Deer Creek ESM shaft
will be 0.131 percent.
Pio
= There is a 10
percent probability
that the methane
concentration in the
Deer Creek ESM shaft
will be 0.211 percent
or greater.
p90 = There is a 90
percent probability
that the methane
concentration in the
Deer Creek ESM shaft
will be 0.081 percent
or greater.
CMM Capture
The West Elk Mine regularly employs GVBs as a component of its methane ventilation program, with the
production from GVBs ranging between 12 and 71 percent of total methane liberated, and an average
contribution of 41 percent since the mine began reporting this information in 2011.
The general practice for the mine is to vent this gas to the atmosphere, occasionally transporting gas to
burners located in Sylvester Gulch to heat the air that is pumped into the mine. This is only done during
the winter months and utilizes only a very small percentage of drained gob gas. The method that the
mine uses to gather and transport the gas for this task is the same concept that is envisioned for the
capture and use projects evaluated in this study, with the exception that in this study we assume that all
available gas produced from active GVBs will be utilized or destroyed, rather than vented. Given that
methane has a global warming potential (GWP) of greater than 36 times that of COz when measured
over a 100 -year period and 87 times that of CO2 when measured over a 20 -year period, destruction of
this gas, as opposed to venting it, will have a positive impact on the local and regional environment. For
the purposes of this study, a GWP of 25 is used to calculate project emission reductions and the amount
of carbon emissions credits generated, as 25 is the value that is currently used by the carbon markets.
10