Jamie Wilson, Louis C. Thanukos, Ph.D.
Applied Environmental Consultants,
a JBR Company
 How did greenhouse gases (GHGs) become
regulated?

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Supreme Court decision in April 2007 ruled that
greenhouse gases are air pollutants covered by
the Clean Air Act.
In April 2009, EPA responded by proposing the
“endangerment” and “cause and contribute”
findings:

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emissions of greenhouse gases from new motor
vehicles cause or contribute to air pollution which
may reasonably be anticipated to endanger public
health or welfare.
Findings finalized in December 2009.
 EPA passed the light duty motor vehicle emission
standards that regulated emissions of six GHG
pollutants
 This meant that GHG were going to become
regulated pollutants under the Clean Air Act
 GHG emissions from stationary sources would
then be subject to New Source Review
permitting, specifically, Prevention of Significant
Deterioration (PSD)
 The PSD thresholds are much too low for GHGs
 Therefore, EPA proposed and in May 2010
finalized the GHG “Tailoring Rule”
 Goal was to reduce GHG emissions only from the
largest sources:

New stationary sources that emit 100,000 tons per
year (tpy) or more of carbon dioxide equivalents
(CO2e) based on the global warming potential of each
of the six GHG pollutants (CO2e is an internationally
accepted measure)

Modified stationary sources that emit 75,000 tpy or
more of CO2e

New sources or modifications must have mass-based
GHG emission increases that follow the traditional
PSD thresholds in addition to the increase in CO2e
 The key components of PSD apply to GHGs,
including a Best Available Control Technology
(BACT) analysis.
 BACT is typically a “top-down” approach:
1.
2.
3.
4.
5.
Identify available control options
Eliminate technically infeasible options
Rank options by control effectiveness
Evaluate most effective controls and emission
limits achievable
Select BACT
 EPA’s November 2010 guidance supports the top-
down approach for evaluating GHG BACT.


All available control options should be evaluated and
ranked in descending order of control effectiveness.
Select the “top” option unless technical
considerations, energy, environmental, or economic
impacts justify that option is not “achievable”.
 GHG BACT should be based on CO2e, not on
individual GHG pollutants
 EPA’s guidance points first and foremost to
energy efficiency
 Step 1 of BACT involves looking at all options for
reducing emissions—regardless of the source type
at which the control was implemented. This
may include:

Inherently lower-emitting processes and designs

Add-on technologies

Control methods applied at similar emissions sources

Feasible combinations of these technologies

The applicant is not required to include options that
“fundamentally redefine the nature of the source”
 Clean fuels are to be considered unless they
redefine the source (e.g., natural gas in lieu
of coal for a coal-fired power plant usually
redefines the source)
 EPA will consider granting more “innovative
control technology” waivers [See 40 CFR
52.21(b)(19)]
 Carbon Capture and Storage (CCS) is
considered “available” by EPA for large CO2emitting facilities
 No off-site impacts considered; must represent
emissions reduction at facility
 EPA guidance leaves door open for stricter
interpretations by permitting authorities
 As applicable, use EPA’s source category-specific
white papers as a starting point:
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Electric generating units
Large ICI boilers
Pulp and paper
Cement
Iron and steel industry
Refineries
Nitric acid plants
 In order to elimination an option, need to show the
technology is infeasible based on physical, chemical,
or engineering principles.
 Is the technology available?


Reached licensing and commercial development stage
Compliance with an applicable BACT limit has been
demonstrated at similar facility
 EPA guidance states that lack of vendor guarantees
for GHG emissions is not sufficient to eliminate an
option
 CCS generally isn’t expected to be “reasonable” yet
for most sources
 Rank the controls with the best at the top
 Must rank logical combinations of the technologies
 Method of measurement historically has been:

Control efficiency,

Expected emission rate, or

Expected emissions reduction
 For GHGs, EPA guidance suggests an efficiency-based
control effectiveness to ensure that the best controls
are, in fact, listed first.

Consider thermal efficiency by using emissions per unit
of output (rather than per unit of fuel input)
 Beginning with the top-ranked control
option, evaluate the economic, energy, and
environmental impacts to ensure it is
achievable
 Historically, focus has been on economic
considerations, but EPA guidance suggests
other impacts are significant for GHG BACT.


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Economics: direct impacts in $/ton
Energy: direct energy consumption
Environmental: indirect or collateral impacts
 From EPA’s November 2010 PSD and Title V
Permitting Guidance for Greenhouse Gases:
“There are compelling public health and welfare
reasons for BACT to require all GHG reductions that
are achievable, considering economic impacts and
the other listed statutory factors.”
 Environmental impacts analysis needs to
consider interpollutant increases
 Economic evaluation may be cursory if costs
are extraordinary
 No cost effectiveness threshold ($/ton CO2e)
provided in the EPA guidance

Work Group’s Interim Phase I Report identifies cost
effectiveness range from $3-$150/ton CO2e
 Additional economic factors (new for GHGs):
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High control cost relative to project cost
Potential movement to overseas production
Local job losses
 Permitting authority (and applicant!) must
provide adequate justification for eliminating
control options
 Select BACT based on the most effective control
option (or combination of options) that was not
eliminated in Step 4
 Form of permitted BACT standards varies but
should consider or may include:



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Emission limits
Averaging time periods
Equipment specifications
Work practices
Associated monitoring, recordkeeping, and reporting
 EPA advocates BACT limits with longer
averaging periods to address GHG emissions
 BACT for GHGs may include work practices
such as an Environmental Management
System (EMS) focused on energy efficiency


ENERGY STAR program provides guidance
BACT limit may include implementation of
energy saving measures identified by the EMS
 Work practices are only acceptable in lieu of
a numerical emission limit if it is technically
impractical to establish or ensure compliance
with a numerical limit.
 EPA’s sample GHG BACT assessments

Municipal solid waste landfill

Natural gas-fired boiler
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Hydrogen plant at petroleum refinery

Coal-fired electricity generating facility
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Kiln at a cement plant
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Natural gas compressor station
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Gas-fired combined cycle power plant
 PSD BACT determinations for criteria pollutants
have a long and sordid history
 GHG BACT can benefit from that experience but
opens up a new realm of opportunity for
judgment calls by the regulatory agencies
 Review EPA’s white papers and sample BACT
analyses that may be relevant to your industry
or equipment.
 Always keep energy efficiency in mind when
designing a new facility or a modification to an
existing facility!
Jamie Wilson
(480) 829-0457
[email protected]
www.aecinc.org