2008-06-09_REVISION - C1980007 ‎(3)‎

• Permit No: C1980007
• IBM Index Class Name: Revision
• Doc Date: 6/9/2008
• Doc Name: Revised Pages Part 2
• Type & Sequence: TR111
• Media Type: D
• Archive: No

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Chapter 3
activities would occur during the project from
all systems including: vertical. (MDWs),
horizontal, and main mine fans. Methane is
over 20 times more effective in trapping heat in
the atmosphere than COZ over a 100-year
period. Methane; emissions, from an air permit
perspective, are not regulated by the State of
Colorado. Preliminary modeling results using
EPA's SCREEN3 air model indicate that
methane concentrations from the methane
drainage wells would result in an increase of
breathing zone methane concentrations in air to
one tenth of one percent (0.1 %) by volume, at a
distance of 50 meters from the source. This is
below the 1Vline Safety and Health
Administration (MSHA) level of one percent.
Quarterly reporting of methane emissions to
BLM is considered confidential information
and cannot be released by the Forest Service.
However, the values used to estimate methane
emissions included in the analysis were based
on values associated with a 5 year average. As
mining in the B Seam is completed, E seam
coal will replace those values with the lower
levels indicated below.
To assess the contribution to greenhouse gasses
the following assumptions were used:
• Based on a Gas-In-Place Study that MCC
had completed in 2006 by Slumberger, the
E Seam methane is anticipated to be 50 to
60 percent of that in the B seam.
• Using official data provided to BLM by
MCC for the B seam releases of methane,
all systems vertical (MDWs), horizontal,
and main mine fans released an average of
13 to 17 million cubic feet per day of
methane.
• Horizontal systems are no longer used and
are not expected to be used in the future.
This reduces the releases by 2 million
cubic feet per day associated with
horizontal drainage, leaving an average of
11 to 15 million cubic feet per day to
represent current conditions of the B seam.
For the following calculations, the middle
(13 million cubic feet per day} will be
used.
Using the above assumptions, the following
conclusions can be made:
As stated earlier, E seam methane is estimated
to be 50 to 60 percent of the B seam average
(13 million cubic feet per day), which amounts
to 6.5 to 7.8 million cubic feet per day, or 2.4 to
2.8 billion cubic feet per year.
In order to calculate the contribution of the
project to overall greenhouse gas emissions,
this predicted methane release was converted to
"CO2 equivalent". This conversion results in
approximately 960,960 to 1,131,200 metric
tons (tonnes) of COZ equivalent released to the
atmosphere per year by the proposed action.
Based on potential COZ equivalent emissions
calculated above, the proposed action would
increase potential greenhouse gas emissions in
Colorado from fossil fuel combustion by
approximately 1.3 percent (calculated as CO2
equivalent). It should be noted that this
percentage increase considers only emissions
from fossil fuel combustion and the percentage
would decrease if other sources of greenhouse
gases (e.g., landfill gas, oil and natural gas
operations, wastewater treatment, and ruminant
livestock, etc.) were included in the calculation.
Additionally, this calculation considers only
emissions from fossil fuel combustion in
Colorado, and not the US (as coal mine
methane in the US accounts for approximately
5.5 percent of methane released) or worldwide
emissions of all greenhouse gases (including
water vapor which is the largest contributor to
the "greenhouse effect" and comprises
approximately 95 percent of all greenhouse
gases) that theoretically affect global warming.
It is not possible to estimate or calculate the
effect that methane emissions from this project
would have on global wainling. The CEQ
regulations for implementing NEPA at 40 CFR
1502.22 discuss evaluating reasonably
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60 Deer Creek Ventilation Shaft and E Seain Methane Drainage Wells FEIS