(sffiz)
%«o^
Source Specific Federal Implementation Plan
for Implementing Best Available Retrofit
Technology for Four Corners Power Plant:
Navajo Nation
Response to Comments for Proposal and
Supplemental Proposal
U. S. Environmental Protection Agency
Region 9
Air Division
San Francisco, CA 94105
August 2012
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Table of Contents
Acronyms and Abbreviations 3
1.0 Introduction 7
1.1 Background 7
1.2 The Commenters 7
1.3 Organization of This Document 8
2.0 Oral Testimony at the Public Hearings and Mass Comment Campaigns 18
2.1 Oral Testimony at the Public Hearings 18
2.2 Mass Comment Campaigns 26
3.0 Comments on Factor One - Cost of Controls 33
3.1 Comments on the Analysis of the Cost of SCR at FCPP 33
3.2 Comments on Top-Down Analysis Versus Incremental Cost Effectiveness 46
3.3 Other Comments on Factor One 49
4.0 Comments on Factor Two - Economic, Energy, and Non-Air Quality Environmental
Impacts 52
4.1 Comments on Economic Impacts 52
4.1.1 General Comments on Economic Impacts 52
4.1.2 Comments on EPA's Economic Analysis 59
4.2 Comments on Energy and Non-Air Quality Environmental Impacts 65
5.0 Comments on Factor Three - Existing Controls at FCPP 76
6.0 Comments on Factor Four - Remaining Useful Life of FCPP 77
7.0 Comments on Factor Five - Anticipated Visibility Improvements 82
8.0 Comments on BART Determinations 98
8.1 Comments on the Proposed BART Determination for NOx 98
8.2 Comments on the Proposed BART Determination for PM 124
8.3 Comments on BART for SO2 129
8.4 Other Comments on BART 133
9.0 Comments on APS's Alternative Proposal and EPA's Supplemental Proposal 139
10.0 Other Comments 151
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Acronyms and Abbreviations
Pollutants
C02 Carbon dioxide
GHG Green House Gas
H2S04 Sulfuric acid
NOx Nitrogen oxides
PM Particulate matter
PMio Particulate matter less than 10 micrometers
PM2.5 Particulate matter less than 2.5 micrometers
502 Sulfur dioxide
503 Sulfur trioxide
Units
Btu British thermal unit
kW Kilowatt
kW-hr Kilowatt-hour
lb Pound
MMBtu Million British thermal units
MW Megawatt
MWh Megawatt hour
ppb Part per billion
TBtu Trillion British thermal units
tpy Tons per year
Acronyms and Abbreviations
ADEQ Arizona Department of Environmental Quality
ANPR Advance Notice of Proposed Rulemaking
APA Administrative Procedure Act
APS Arizona Public Service
BACT Best Available Control Technology
BART Best Available Retrofit Technology
BAU Business as usual
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Acronyms and Abbreviations
BOD
Boiler Operating Day
CAA
Clean Air Act (42 U.S.C. 7401 - 7671q)
CAIR
Clean Air Act Interstate Rule
CAMD
Clean Air Markets Division (EPA)
CBI
Confidential Business Information
CCW
Coal Combustion Waste
CEMS
Continuous emissions monitoring system
CFR
Code of Federal Regulations
CO
Colorado
COMS
Continuous opacity monitoring system
COPD
Chronic obstructive pulmonary disease
COS
Combustion optimization systems
CRF
Capital Recovery Factor
DC Circuit
Federal Court of Appeals for the District of Columbia Circuit
DREF
Desert Rock Energy Facility
DOE
Department of Energy
DOI
Department of the Interior
dv
Deciview
EIS
Environmental Impact Statement
EGU
Electric generating unit
ELGs
Effluent limitation guidelines
EPA
U.S. Environmental Protection Agency
EPRI
Electric Power Research Institute
ESA
Endangered Species Act
ESP
Wet membrane electrostatic precipitator
FCPP
Four Corners Power Plant
FERC
Federal Energy Regulatory Commission
FIP
Federal Implementation Plan
FLM
Federal Land Manager
FR
Federal Register
£RH
Relative humidity adjustment factor
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Acronyms and Abbreviations
HERT
High Energy Reagent Technology
IWAQM
Interagency Workgroup on Air Quality Modeling
LNB
Low N0X burner
MACT
Maximum Achievable Control Technology
MATS
Mercury and Air Toxics Standards
MRR
Mandatory Reporting Rule
NAAQS
National Ambient Air Quality Standards
NEPA
National Environmental Policy Act
NESHAP
National Emission Standards for Hazardous Air Pollutants
NGS
Navajo Generating Station
NM
New Mexico
NMED
New Mexico Environment Department
NNEPA
Navajo Nation Environmental Protection Agency
NPDES
National Pollutant Discharge Elimination System
NPS
National Park Service
NREL
National Renewal Energy Laboratory
NSPS
New Source Performance Standard
NSR
New Source Review
OAR
Office of Air and Radiation (EPA)
OMB
Office of Management and Budget
OFA
Overfire air
PSD
Prevention of Significant Deterioration
RAVI BART Reasonably Attributable Visibility Impairment Best Available Retrofit
Technology
RCRA
Resource Conservation and Recovery Act
RHR
Regional Haze Rule
RIA
Regulatory Impact Analysis
ROFA
Rotating Overfire Air
RTC
Response to Comments
SCE
Southern California Edison
SCR
Selective catalytic reduction
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Acronyms and Abbreviations
SIP
State Implementation Plan
SJGS
San Juan Generating Station
SNCR
Selective non-catalytic reduction
TAG
Technical Assistance Guidance
TAR
Tribal Authority Rule
TIP
Tribal Implementation Plan
TSD
Technical Support Document
U.S.C.
United States Code
UARG
Utility Air Regulatory Group
U.S.
United States
VOCs
Volatile Organic Compounds
WRAP
Western Regional Air Partnership
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1.0 Introduction
1.1 Background
On October 19, 2010, the U.S. Environmental Protection Agency (EPA or "we")
proposed a source-specific Federal Implementation Plan (FIP) requiring the Four Corners Power
Plant (FCPP), located on the Navajo Nation, to achieve emissions reductions required by the
Clean Air Act's (CAA's) Best Available Retrofit Technology (BART) provision.1 On
November 24, 2010, Arizona Public Service (APS) acting on behalf of FCPP's owners submitted
a letter to EPA offering an alternative to reduce visibility-impairing pollution. The EPA
supplemented the October 2010 BART proposal with its technical evaluation of APS's
alternative. In a February 25, 2011 supplemental proposal, we proposed to find that an
alternative emissions control strategy would achieve more progress than EPA's BART proposal
towards achieving visibility improvements in the surrounding Class I areas.2
1.2 The Commenters
In the October 2010 proposal, EPA stated that public comments were to be submitted by
December 20, 2010. As a result of APS's alternative and our supplemental proposal, the due date
for public comments was subsequently extended to May 2, 2011.
The EPA held four public hearings on the proposed BART determination and
supplemental proposal in the Four Corners area on March 29, 30, and 31, 2011. In all, 90 oral
testimonies were presented at the public hearings. The oral testimony is discussed further in
Section 2.1 of this document
We received nearly 13,000 written comments. Of these, over 12,800 comments came
from private citizens who submitted substantively similar comments. These comments are
discussed further in Section 2.2 of this document.
We received an additional 110 unique written comments (not including duplicates,
requests for extension of the public comment period, or requests for additional hearings). These
unique comments also do not include letters unrelated to the rulemaking. The comments can be
broken down by general type as follows: 78 from private citizens, 8 from environmental
advocacy groups, 4 from the owners of FCPP, 5 from state/local government entities, 4 from
public interest advocacy groups, 2 from tribes, 4 from utility industry associations, 3 from
federal agencies, 1 from a U.S. Senator, and 1 from the operator of the Navajo Mine. These
comments are listed at the end of this section. The list of comments also includes an entry for all
the written comments submitted at the public hearings, which are not included in the preceding
totals. The comments are summarized by topic in Sections 3.0 through 10.0 of this document.
1 The BART determination was proposed on October 19, 2010 in the Federal Register, Volume 75, beginning on
page 64,221 (75 FR 64221, October 19, 2010).
2 76 FR 10530, February 25, 2011.
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1.3 Organization of This Document
After this introductory section, this document includes nine additional sections as
follows:
• Section 2.0 - Oral Testimony at the Public Hearing and Mass Comment Campaigns
• Section 3.0- Comments on Factor One - Cost of Controls
• Section 4.0 - Comments on Factor Two - Economic, Energy, and Non-Air Quality
Environmental Impacts
• Section 5.0 - Comments on Factor Three - Existing Controls at FCPP
• Section 6.0 - Comments on Factor Four - Remaining Useful Life of FCPP
• Section 7.0 - Comments on Factor Five - Anticipated Visibility Improvements
• Section 8.0 - Comments on BART Determinations
• Section 9.0 - Comments on APS's Alternative Proposal and EPA's Supplemental
Proposal
• Section 10.0 - Other Comments
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LIST OF WRITTEN COMMENTS
Document Id 3
EPA-R09-OAR-
2010-0683-XXXX
Title
Type of
Commenter
Notes
0067
Colorado-based organizations
Group of
Environmental
Advocacy
Groups
Request for
additional
hearing in
Durango, CO
0068
Edward Z. Fox, Vice President and Chief Sustainability Officer, Arizona
Public Service
Co-owners of
FCPP
Request for
comment period
extension
0069
Stephen B. Etsitty, Executive Director, Navajo Nation Environmental
Protection Agency
Tribal Agency
Request for
additional
hearings and
workshops
0071
Richard M. Hay slip, Associate General Manager, Salt River Project
Co-owners of
FCPP
Request for
comment period
extension
0072
Erik Bakken, Manager, Environmental Services and Land Management,
Tucson Electric Power Company
Co-owners of
FCPP
Request for
comment period
extension
0073
Wild Earth Guardians
Environmental
Advocacy Group
0075
Edward Z. Fox, Vice President and Chief Sustainability Officer, Arizona
Public Service Company
Co-owners of
FCPP
Alternative
proposal
3 Document ID identifies written comments found in Docket No. EPA-R09-OAR-2010-0683 by document number.
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LIST OF WRITTEN COMMENTS
Document Id 3
EPA-R09-OAR-
2010-0683-XXXX
Title
Type of
Commenter
Notes
0082
Patrick Themig, Vice President, PNM Resources, Inc.
Co-owners of
FCPP
Request for
comment period
extension
0083
Chris Foran, Steering Committee Representative, Montezuma Climate
Action Network
Environmental
Advocacy Group
Duplicate of
0146
0084
Annika Bergen
Private Citizen
0085
Charles A. Haley
Private Citizen
0086
Lair Carlson, Publisher Cell Door Magazine
Private Citizen
0087
Irene Hamilton
Private Citizen
0088
Ed Mosimann
Private Citizen
0089
Zachary Katz, Orien McGlamery, Linda P. Sency, Kathy Brown, Deb
Campbell
Private Citizen
0091
Martha Evers
Private Citizen
0092
Brian Hoffman
Private Citizen
0093
Phyllis Hollenbeck
Private Citizen
0094
Jodi Foran, Past-president; League of Women Voters of Montezuma
County
Public Interest
Advocacy Group
0095
Stephanie Kodish, National Parks Conservation Association
Environmental
Advocacy Group
0105
Michael Rendon, Mayor, City of Durango, Colorado
State/Local
Government
0106
Kellie C. Hotter, Chair, La Plata County Board of County
Commissioners
State/Local
Government
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LIST OF WRITTEN COMMENTS
Document Id 3
EPA-R09-OAR-
2010-0683-XXXX
Title
Type of
Commenter
Notes
0107
Robert Ukeiley, Law Office of Robert Ukeiley
Private Citizen
0108
Wallace L. White, Commissioner, La Plata County Board of County
Commissioners
State/Local
Government
0112
League of Women Voters of Montezuma County
Public Interest
Advocacy Group
0113
Paul Tourangeau, Director, Air Pollution Control Division, Colorado
Department of Public Health and Environment
State/Local
Government
0116
Ravi Grover
Private Citizen
0117
Paul Nazaryk, Environmental Regulatory Affairs, BHP Billiton
Operator of
Navajo Mine
0118
Anonymous
Private Citizen
0119
Anonymous
Private Citizen
0122
Margaret Ackerman
Private Citizen
0123
Dan Barnes
Private Citizen
0124
Larry Berger
Private Citizen
0125
William Botsford
Private Citizen
0126
Linda Bunk
Private Citizen
0127
Laird Carlson
Private Citizen
0128
Bill Carver
Private Citizen
0129
Burt Coleman and Dell Manners
Private Citizen
0130
Patty Cordova, LWVCO President
Private Citizen
0131
Jerry and Julie Crockford
Private Citizen
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LIST OF WRITTEN COMMENTS
Document Id 3
EPA-R09-OAR-
2010-0683-XXXX
Title
Type of
Commenter
Notes
0132
Geraldine Duffy
Private Citizen
0133
Barbara Garlick
Private Citizen
0134
Bruce A. Garlick
Private Citizen
0135
Joe Griffith and Dianne Donovan
Private Citizen
0136
Ana Hale
Private Citizen
0137
Charles A. Haley
Private Citizen
0138
Irene Hamilton
Private Citizen
0139
Wes and Pat Hartman
Private Citizen
0140
Jill and Rich Hoehlein
Private Citizen
0141
Kristine Johnson
Private Citizen
0142
John Larry
Private Citizen
Unrelated to the
rulemaking.
0143
Stephanie Huss, President, League of Women Voters of La Plata County
Public Interest
Advocacy Group
0144
Ed and Julie Ward Lehner
Private Citizen
0145
Claire May
Private Citizen
0146
Chris Foran, Steering Committee Representative, Montezuma Climate
Action Network
Environmental
Advocacy Group
0147
Ed Mosimann
Private Citizen
0148
Lynne Murison
Private Citizen
0149
Harry Riegle
Private Citizen
0150
Sean Babington, Office of Senator Michael Bennet
U.S. Senator
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LIST OF WRITTEN COMMENTS
Document Id 3
EPA-R09-OAR-
2010-0683-XXXX
Title
Type of
Commenter
Notes
0151
Francis Slater
Private Citizen
0152
Brenda Jarrell, Air Quality Program Manager, Southern Ute Indian Tribe
Tribe
0153
Elaine Spence
Private Citizen
0154
Dan Tobin
Private Citizen
0155
Brian von Dedenroth
Private Citizen
0156
Bob Waggoner
Private Citizen
0157
Joe Ward
Private Citizen
0158
D.J. Webb
Private Citizen
0159
Richard E. White
Private Citizen
0160
Richard White
Private Citizen
0161
Janet Wilson
Private Citizen
0162
Zita Xavier
Private Citizen
0163
Vincent H. Yazzie
Private Citizen
0164
Vincent H. Yazzie
Private Citizen
0165
Owen M. Lopez, McCune Foundation
Private Citizen
0166
D. House
Private Citizen
0167
Christopher Lish
Private Citizen
0168
Arie Hoekstra, Vice President, Generation, Tucson Electric Power
Co-owner of
FCPP
0169
A. Gwen Eklund, Consulting Business Manager, WEST Associates
Utility Industry
Association
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LIST OF WRITTEN COMMENTS
Document Id 3
EPA-R09-OAR-
2010-0683-XXXX
Title
Type of
Commenter
Notes
0170
Brian Abel and Patricia Padian
Private Citizen
0171
Dell Manners
Private Citizen
0172
Montezuma-Cortez School
Private Citizen
0173
Ann Perkins-Parrott
Private Citizen
0174
Richard M. Hay slip, Associate General Manager, Salt River Project
Co-owner of
FCPP
0175
Corbin L. Newman, Jr., Regional Forester, USFS
Federal Agency
0176
Edward Z. Fox, Vice President and Chief Sustainability Officer, Arizona
Public Service Company
Co-owner of
FCPP
0177
Edward Z. Fox, Vice President and Chief Sustainability Officer, Arizona
Public Service Company
Co-owner of
FCPP
0178
Laura McHenry
Private Citizen
0179
Patrick Themig, Vice President, Generation, Public Service Company of
New Mexico
Co-owner of
FCPP
0180
Brynn Johns
Private Citizen
0181
Michelle Reott
Private Citizen
0182
Mike Eisenfeld, New Mexico Energy Coordinator, San Juan Citizens
Alliance
Environmental
Advocacy Group
0183
Pamela Campos, Attorney, Environmental Defense Fund
Environmental
Advocacy Group
0184
Jeremy Nichols, Climate and Energy Program Director, WildEarth
Guardians
Environmental
Advocacy Group
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LIST OF WRITTEN COMMENTS
Document Id 3
EPA-R09-OAR-
2010-0683-XXXX
Title
Type of
Commenter
Notes
0185
Aaron Flynn, Counsel to Arizona Public Service Company, Central
Arizona Water Conservation District, and Salt River Project Agricultural
Improvement and Power District
Co-owner of
FCPP
0186
Erin and Fred Bird
Private Citizen
0187
Aaron Flynn, Utility Air Regulatory Group
Utility Industry
Association
0188
Heidi Keshet
Private Citizen
0189
R. Frank (and 682 others)
Private Citizen
Mass Campaign
0190
All Written Comments Received during March 29-31, 2011 Public
Hearings and Open Houses
Range of
commenters
0191
League of Women Voters of Montezuma County
Public Interest
Advocacy Group
Duplicate of
0112
0192
Kathy and Jim Merrill
Private Citizen
0193
Post Cards
Private Citizen
Mass Campaign
0194
Don Hancock, Steering Committee Chairperson, Coalition for Clean
Affordable Energy (CCAE)
Environmental
Advocacy Group
0195
Lau Ackerman
Private Citizen
0196
Mass EPA Card Campaign
Private Citizen
Mass Campaign
0197
Larry Berger
Private Citizen
0198
Jackie Candelaria
Private Citizen
0199
Laurie Carpino
Private Citizen
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LIST OF WRITTEN COMMENTS
Document Id 3
EPA-R09-OAR-
2010-0683-XXXX
Title
Type of
Commenter
Notes
0200
John W. Suthers, Colorado Attorney General, Colorado Department of
Public Health and Environment (CDPHE)
State/Local
Government
0201
John Culver
Private Citizen
0202
Clint McKnight
Private Citizen
0203
Mass Email Campaign
Private Citizen
Mass Campaign
0204
Mass Mail Campaign
Private Citizen
Mass Campaign
0205
Mass Mail Campaign
Private Citizen
Mass Campaign
0206
Mass Mail Campaign
Private Citizen
Mass Campaign
0207
Mass Mail Campaign
Private Citizen
Mass Campaign
0208
Evelyn Ramey
Private Citizen
0209
Dave Rich
Private Citizen
0210
Bruce E. and Suzzanne D. Rodman
Private Citizen
0211
Roxanne Rogers
Private Citizen
0212
Mass Email Campaign
Private Citizen
Mass Campaign
0213
Shan and Regina Wells
Private Citizen
0214
Elizabeth M. Wheeler
Private Citizen
0215
Mass Email Campaign
Private Citizen
0216
Vincent H. Yazzie
Private Citizen
0218
Jeremy Nichols, Climate and Energy Program Director, WildEarth
Guardians
Environmental
Advocacy Group
Attachment to
0184
0223
President Shelly, Navajo Nation
Tribe
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LIST OF WRITTEN COMMENTS
Document Id 3
EPA-R09-OAR-
2010-0683-XXXX
Title
Type of
Commenter
Notes
0224
Alletta Belin, Counselor to the Deputy Secretary, U.S. Department of the
Interior
Federal Agency
Transmits
National Park
Service (NPS)
comments
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2.0 Oral Testimony at the Public Hearings and Mass Comment
Campaigns
2.1 Oral Testimony at the Public Hearings
The EPA held four public hearings in the Four Corners area on March 29, 30, and 31,
2011. In conjunction with each hearing (generally before the hearing), EPA conducted an
information session in which EPA experts explained the BART proposal and better-than-BART
supplemental proposal for FCPP to interested attendees with the aid of illustrative posters. An
interpreter for speakers of Dine, the Navajo language, was present for three of the information
sessions and public hearings.
In all, a total of 90 oral testimonies were presented at the four hearings, although several
persons spoke at more than one hearing and two persons gave separate testimony on behalf of
two different entities at a single hearing. Most speakers spoke as private citizens, but there were
also representatives of the interested industries (the co-owners of FCPP and operator of the
Navajo Mine), environmental advocacy groups, public interest advocacy groups, and local
government. The location and time of each public hearing and information session are given
below, along with the number and types of speakers at each hearing.
PUBLIC HEARINGS AND INFORMATION SESSIONS
Time
Venue
Info
Public
Date
(with Transcript Docket Number)
Session
Hearing
Commenters
March 29
Phil L. Thomas Performing Arts
3-6
7-9
Private citizens - 16
Center
Shiprock, New Mexico
p.m.
p.m.
Industry - 1
Environmental - 2
(EPA-R09-OAR-2010-0683-0227)
March 30
Nenahnezad Chapter House
9 a.m. -
-1 p.m.
Private citizens - 10
Fruitland, New Mexico
(EPA-R09-OAR-2010-0683-0225)
(concurrent)
Industry - 1
Local government
(Chapters) - 2
March 30
San Juan College
3-5
6-9
Private citizens - 25
Farmington, New Mexico
(EPA-R09-OAR-2010-0683-0226)
p.m.
p.m.
Industry - 3
Environmental - 2
March 31
Fort Lewis College
3-5
6-9
Private citizens - 21
Durango, Colorado
(EPA-R09-OAR-2010-0683-0228)
p.m.
p.m.
Public interest - 2
Environmental - 4
Local government
(County) - 1
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The comments presented in oral testimony at the public hearings are summarized below,
with the exception of comments from entities that submitted written comments which duplicated
their oral testimony. For example, APS and the San Juan Citizens Alliance submitted extensive
written, technical comments that are summarized in the other sections of this document; their
oral comments on the same topics are not included in this section. The transcripts from and the
materials presented by EPA during these hearings are also available in the docket.4
Comment:
The majority of commenters favored the supplemental proposal or more stringent
requirements for FCPP because the commenters consider visibility and air quality in the Four
Corners region to be generally poor. A few argued that FCPP should be shut down rather than
being retrofit with controls. On the other hand, several commenters noted that FCPP and the
Navajo Mine provide many jobs in the area and that their payments to the Navajo Nation make
up a large portion of the Nation's revenues. These commenters cautioned that EPA must
carefully balance the environmental benefit of any requirements for FCPP with the potential
adverse impacts to the Navajo Nation and the region that would ensue were FCPP to close as a
result of EPA regulation.
Many commenters favor stringent controls on FCPP because they assert that emissions
from FCPP represent a public health issue. These commenters indicated that these emissions are
to blame for health problems in the area, such as respiratory disease and cancer, which many
argue have become more prevalent in recent years. The commenters often said that the health of
succeeding generations should be an important consideration. However, a few commenters
questioned that FCPP's emissions are causing such health effects. A number of commenters on
both sides of this issue requested that health studies be undertaken to determine the health
impacts of FCPP emissions.
Many speakers spoke in favor of stringent controls on FCPP because of the haze that is
very common in the area, believing that it is due to FCPP. Some commenters indicated that the
haze diminishes the beauty of the area, which is a quality of life issue for residents as well as an
economic issue because of the importance of tourism to the economy of the area.
Several commenters support stringent controls because they argue that emissions from
FCPP are having negative impacts on the land and water in the area, as well as the air. Some
expressed fear that emissions from the plant, including mercury and other toxic compounds, are
harming ecosystems in the area, including rare and endangered plant species, endangered fish
species, pollinators, and amphibians. Some living near to the plant assert that it is responsible for
killing native plant species that they have depended on for their livestock, and has harmed
traditional dry land farming. A number of Navajo commenters stated that pollution of the air,
water, and land is contrary to Navajo religious beliefs and cultural traditions.
A number of commenters favor stringent controls on FCPP as a first step in a transition
away from coal-fired power plants to renewable energy sources. Commenters enumerated many
problems with coal as an energy source, including emissions of air pollutants (SO2, NOx, PM,
4 See Document numbers 0109, 0111, and 0225 - 0228 in EPA-R09-OAR-2010-0683.
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August 2012 - Four Corners Power Plant Final Rulemaking - Response to Comments
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mercury and other toxic compounds, acid gases, and Green House Gases (GHGs)), use of large
amounts of water for cooling, and production of large amounts of ash or coal combustion waste
(CCW). Several noted that New Mexico and the Four Corners area are ideally suited for solar
and wind energy projects. Some commenters stated that a transition to renewable energy could
economically benefit the Navajo Nation.
Response:
Protection of human health and the environment is EPA's mission, andforms the basis
for many Agency actions, including establishing the National Ambient Air Quality Standards
(NAAQS), and promulgation of regulations such as the New Source Performance Standards
(NSPS) and the National Emission Standards for Hazardous Air Pollutants (NESHAP). In
addition to Clean Air Act requirements to protect human health, in the 1977 Clean Air Act
Amendments, Congress also declared as a national goal the prevention of any future, and the
remedying of any existing, impairment of visibility in mandatory class I Federal areas which
impairment results from manmade air pollution (See CAA §169A). In 1999, EPA issued the final
Regional Haze Rule (RHR), which included the requirement for facilities of a certain age to
install the Best Available Retrofit Technology (BART) to reduce emissions of visibility impairing
pollutants. Therefore, the focus of implementation plans developed under the RHR, is to improve
visibility at National Parks and Wilderness Areas. EPA agrees that visibility-impairing
pollutants can impact human and ecosystem health. Emissions of hazardous air pollutants such
as mercury are not visibility-impairing pollutants, and as a result are beyond the scope of our
BART analysis. EPA agrees that health studies may provide useful information, however, these
studies are beyond the scope of a BART analysis. Emissions of hazardous air pollutants
(HAPs)from various source categories are addressed generally through National Emission
Standards for Hazardous Air Pollutants (NESHAPs) and EPA addresses mercury emissions from
power plants specifically in the final Mercury and Air Toxics (MATS) Rule which was published
in the Federal Register on February 16, 2012 (77 FR 9304).
EPA is aware of the contribution of FCPP and the Navajo Mine to the economy of the
Navajo Nation and the Four Corners region. At the request of the Navajo Nation, pursuant to
EPA's customary practice of engaging in extensive and meaningful consultation with tribes, EPA
commissioned an analysis to estimate the potential adverse impacts to the Navajo Nation of
APS's option to retire Units 13 and will provide the report to the Navajo Nation by letter as a
follow-up to our consultation. EPA did not rely on this analysis in our final determination.
Regarding comments in favor of transitioning from coal to renewable energy, the RHR
establishes a five step process EPA must follow when performing a case-by-case BART
determination. Although EPA agrees that transitioning to renewable energy is a worthwhile
goal, the BART Guidelines5 state that under" Step 1: How do I identify all available retrofit
emission control techniques? ", "[EPA does] not consider BART as a requirement to redesign
the source when considering available control alternatives" (see specifically 70 FR at 39164).
5 See "Regional Haze Regulations and Guidelines for Best Available Retrofit Technology (BART) Determinations",
70 FR 39104, July 6, 2005, in the docket for this rulemaking.
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Comment:
Some commenters asserted the presence of FCPP and several other power plants in and
around the Navajo Nation represent an environmental and economic justice issue. These
commenters pointed out that the electricity from FCPP goes to distant cities, while the pollution
from the plant affects the local area and many communities in the surrounding area are without
electricity. They noted that many in the Navajo Nation live in poverty and their youth have
limited opportunities, while the companies that own and operate FCPP and the Navajo Mine
have reaped large profits. Some expressed frustration with the leaders of the Navajo Nation, who
they asserted have not protected the interests of the local population.
Some of these commenters stated that APS should recognize that FCPP will ultimately
have to shut down and begin to transition to renewable energy sources. The commenters stated
that because it has profited so much from FCPP, APS has a corporate responsibility to facilitate a
just transition for the local area to a renewable energy economy.
Response:
In establishing BART requirements for FCPP in this final rulemaking, EPA will be
increasing the level of environmental protection for all affected populations by requiring
substantial NOx emission reductions. Thus, EPA does not expect any disproportionately high and
adverse human health or environmental effects on any population, including any minority or
low-income population from our final action.
The first step of the BART determination process involves identification of all available
retrofit technologies. As described in the 2005 Regional Haze Rule, redesign of the source is not
considered a requirement when examining available control technologies (70 FR 39104). As an
example, a coal-fired unit would not be required to consider construction of a natural gas-fired
turbine; while it is an inherently less polluting technology, it would require a redesign of the
source. A transition of FCPP to use of renewable energy sources would require a similar
redesign of the FCPP units, and as a result is outside of EPA 's authority under the RHR The
Department of Interior has contracted with the Department of Energy's National Renewable
Energy Laboratory, however, to conduct a phased study on the Navajo Generating Station
(NGS). DOI intends that Phase 2 of this study will examine the potential of long-term energy
production options for NGS, and may include such options as renewable sources. Although the
focus of this study is NGS and not FCPP, because NGS is also located on the Navajo Nation,
results of this study may be relevant to the FCPP area.
Comment:
Some commenters expressed concern related to the ash generated by FCPP. Some of
these indicated that the ash from the facility is unsecured and blows over the nearby area when it
is dry and is washed into the San Juan River when it rains. Some of these commenters blamed
the windblown ash for killing local vegetation in the area. Other commenters refuted these
claims.
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A few speakers raised issues regarding the storage of coal combustion wastes (CCW) at
FCPP. In the most extensive such comments, one environmental advocacy group commenter
supported selective catalytic reduction (SCR) controls at FCPP, but asked that EPA also work to
concurrently address the CCW (fly ash, scrubber sludge and bottom ash) being generated at the
facility. The commenter stated that SCR technology will increase the nitrogen and ammonia
content of the CCW, as well as the pH, very significantly, and possibly increase the quantity of
CCW generated by FCPP, which currently stands at 1.5 million tons per year. The commenter
noted that some of this material is used and recycled as synthetic gypsum, but the majority is
highly toxic and includes pollutants such as lead, arsenic, mercury, cadmium, chromium, and
selenium.
According to the commenter, the facility has historically disposed of CCW in temporary
ash ponds on site and also returned it to the Navajo Mine, where BHP used it as minefill. The
commenter stated that the on-site ash ponds are on about 550 acres directly adjacent to Chaco
Wash, located on the escarpment directly above the wash, which runs due north approximately
1 mile into the San Juan River. The commenter noted that by some estimates, there are tens of
millions of tons of CCW, and perhaps billions of tons, stored in these ash ponds; it is perhaps the
largest storage of toxic CCW in the nation. The commenter asserted that these ash ponds pose a
significant threat, as evidenced by the 2008 failure of the coal ash ponds at the Tennessee Valley
Authority's Kingston Fossil Plant, where a 40-acre plant released over one billion gallons of
toxic CCW into two separate rivers. Like the Tennessee Valley Authority plant, according to the
information and belief of the commenter, FCPP has no emergency preparedness plan for cleanup
of the coal ponds should they breach, and there is no bond for decommissioning these ash ponds.
The commenter stated it is extremely important for the owners of FCPP to address the
liability of decommissioning of Units 1 through 3 and these ash ponds as part of their
decommissioning process. The commenter asked who is going to pay for the cleanup - APS and
the ratepayers, Southern California Edison, the Navajo Nation, or the federal taxpayers?
The commenter asked EPA to support the production of an environmental impact
statement (EIS) to evaluate, among other things, the cost, methodology and liability for cleanup
of these ash ponds, as well as an assessment for a bond or a surety from APS for full CCW
storage needs going forward should Units 4 and 5 remain open under the current plan. The
commenter pointed out that there is a mechanism for getting this done in that the Navajo Nation
recently approved the lease renewal for FCPP, and that lease renewal is subject to review by DOI
and will be subject to NEPA, which requires an EIS. The commenter requested that EPA support
production of an EIS for this, as well as act as a cooperating agency in this process.
Response:
Comments regarding the environmental issues associated with CCW are beyond the
scope of the BART analysis.
On June 21, 2010, EPA proposed and solicited comments on two regulatory options for
establishing national standards for management of CCW (75 FR 35127). Options considered in
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this proposal include regulating CCW as a hazardous waste under Subtitle C of the Resource
Conservation and Recovery Act (RCRA), or establishing new national criteria under the non-
hazardous solid waste requirements in RCRA Subtitle D. In addition, under the Clean Water Act,
EPA has authority to establish effluent limitation guidelines (ELGs), which are national
standards for water pollution reductions developed on an industry-by-industry basis. As part of a
November 8, 2010 consent decree, EPA agreed to revise the ELGs for Steam Electric Power
Generation to address wastewater discharges from CCW storage. Per the consent decree, these
updated ELGs must be proposed by July 23, 2012 and finalized by January 31, 2014.
As noted in the Technical Support Document (TSD)6for our October 19, 2010proposal,
EPA determined that the impact of SCR on fly ash is smaller than the impact of other N0X
control technologies under consideration (in particular low N0X burners) on future salability of
fly ash.
As the commenter notes, a lease renewal for FCPP was signed by the Navajo Nation in
March 2011. This renewal is subject to DOI's review and approval process, which will result in
the publication of an EIS. EPA Region 9 will be a cooperating agency in this process.
Comment:
A commenter representing the operator of the Navajo Mine, BHP Billiton, noted that
EPA's informational posters state that the company has pledged that there will be no layoffs at
the mine if the supplemental proposal is implemented. The commenter clarified that the reduced
coal consumption by FCPP associated with closure of Units 1-3 will necessitate a reduction in
the workforce at the mine, but that the company stated that this reduction can be accomplished
through retirement and attrition without layoffs. The commenter projected that the employment
at the mine ultimately will be reduced by 100 to 200 positions.
Response:
EPA thanks the commenter for the clarification that the mine will not lay off employees if
Units 13 close, but that reduced coal consumption by FCPP associated with the closure of
Units 1 - 3 is likely to result in a workforce reduction through retirement and attrition.
Comment:
A few commenters stated that EPA should conduct a BART determination for SO2 and
reduce these emissions from FCPP to further improve visibility and reduce acid deposition. The
commenters indicated that acid deposition damages ecosystems and degrades Native American
ruins in the area. One commenter asserted that EPA should carry out a BART determination for
CO2 emissions from FCPP because this is the primary GHG.
6 "FCPP Proposal - Technical Support Document", October 6, 2010, Document No. EPA-R09-OAR-2010-0683-
0002.
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Response:
EPA disagrees with this comment. As noted in the 2007 FIP for FCPP,7 the SO 2
emission reductions established by the FIP are close to or the equivalent of BARTfor this
source. Therefore, at the present time, EPA is exercising its discretion under 40 Code of Federal
Regulations (CFR) part 49.11 to find that it is neither necessary or appropriate at this time to
undertake a BART determination for SO 2 for FCPP given the timing of the substantial SO 2
reductions that resultedfrom the 2007FIP.
Regarding the commenter 's concern about green house gas (GHG) emissions, GHGs are
not visibility-impairing pollutants and are not addressed in this action as they are beyond the
scope of the BART requirements in the RHR
As a general matter, EPA continues to develop several regulatory initiatives to address
these. For example, the GHG Mandatory Reporting Rule (MRR)8 requires reporting of emissions
of six GHGs from multiple industrial source categories, and the GHG Tailoring Rule,9
establishes emission thresholds that define when new and existing industrial facilities must
obtain permits. As part of the GHG Tailoring Rule implementation process, the initial phase will
extend to those sources and projects that are already considered major sources for pollutants
other than GHG. As a Title V major source of emissions, the Four Corners Power Plant is
subject to the Title V program and has a Part 71 operating permit.10 As a result, it will be
subject to Title V requirements for GHG. EPA also entered into two proposed settlement
agreements on December 23, 2010 that will include development of GHG emission standards for
new and modified coal-fired power plants.
Comment:
One commenter questioned EPA's development of baseline values using computers. The
commenter stated that computer simulation technology is not accurate enough for many uses at
this time.
Response:
EPA disagrees with this comment. Computer-based visibility modeling plays an
important role in informing many of the policy decisions associated with implementation of the
RHR. The ability to predict how changes in air pollutant emission rates will affect visibility at
Class I areas is critical in determining the control measures that are necessary to meet national
visibility goals. As described in the 1999 RHR, although the national visibility goal was
established by the 1977 Clean Air Act Amendments, EPA deferred action on regional haze until
7 See "Source Specific Federal Implementation Plan for the Navajo Nation: Four Corners Power Plant", 72 FR
25698, May 7, 2007, in the docket for this rulemaking.
8 See "Mandatory Reporting of Greenhouse Gases", 74 FR 56260, October 30, 2009, in the docket for this
rulemaking.
9 See "Prevention of Significant Deterioration and Title V Greenhouse Gas Tailoring Rule", 75 FR 31514, June 3,
2010, in the docket for this rulemaking.
10 "TSD ref [101] FCPP Permits", Document No. EPA-R09-OAR-2010-0683-0057.
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monitoring techniques, modeling capabilities, and the understanding of the pollutants affecting
visibility improved. In the final rule for the 1999 Regional Haze regulations", EPA notes that
the National Academy of Sciences concluded that ' 'current scientific knowledge is adequate and
control technologies are available for taking regulatory action to improve and protect
visibility". As described in the 2004 RHR proposal12 and the final 2005 RHR13 , determining
visibility impacts on an individual source-specific basis involves long-range transport and
diffusion modeling, as well as determining the impacts of atmospheric chemical transformations.
The CALPUFF dispersion model is incorporated into 40 CFRPart 51, Appendix W "Guideline
on Air Quality Models " and is the approved model that is the best suited to address each of these
challenges.
Comment:
A representative of one of the co-owners of FCPP stated that EPA's BART determination
for FCPP should be consistent with the determinations that have been issued by states that are
implementing the Regional Haze Program. The commenter indicated that states have not
determined SCR to be BART. The remainder of the issues raised in this commenter's oral
testimony were also included in the company's written comments and are summarized in the
other sections of this document.
Response:
EPA disagrees with this comment for at least 2 reasons. BART determinations are
conducted on a case-by-case basis, taking into consideration the statutory factors required in a
BART analysis under Section 169A(g)(l) of the CAA , i.e., the costs of compliance, the energy
and nonair quality environmental impacts of compliance, any existing pollution control
technology in use at the source, the remaining useful life of the source, and the degree of
improvement in visibility which may reasonably be anticipated to result from the use of such
technology, as relevant to each source that is subject to BART. As such, the CAA does not
require State agencies, in developing its State Implementation Plans (SIPs), or EPA in
implementing FIPs, to ensure that its BART determinations are consistent with BART
determinations issued by other States. EPA 's BART determination for FCPP was a case-by-case
analysis that considered the statutory factors required by the CAA and as outlined in the BART
Guidelines. EPA provided the analysis for each factor and the rationale for our BART
determination requiring an 80% reduction in plant-wide NOx emissions from FCPP in the TSD
for our October 19, 2010 proposal. Second, the commenter is not correct in its statement that no
state has determined SCR to be BART. The Colorado Department of Public Health and
Environment required SCR as BART on Hay den Station Units 1 and 2.14
11 See "Regional Haze Regulations", 64 FR 35714, July 1, 1999, in the docket for this rulemaking.
12 See "Regional Haze Regulations and Guidelines for Best Available Retrofit Technology (BART) Determinations"
(proposed rule), 69 FR 25184, May 5, 2004, in the docket for this rulemaking.
13 See "Regional Haze Regulations and Guidelines for Best Available Retrofit Technology (BART)
Determinations", 70 FR 39104, July 6, 2005, in the docket for this rulemaking
14See "Hayden BART Final.pdf' in the docket for this rulemaking, also available at
http://www.cdphe.state.co.us/ap/regionalhaze.html.
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2.2 Mass Comment Campaigns
We received many comments from private citizens inspired by mass comment
campaigns. Most of these commenters submitted the templates provided by the sponsoring
organizations without change, but others customized the templates to some degree but without
providing additional substance.
Comments:
Comment 0189 represents an example of 682 postcards EPA received from the
organization Dine CARE at the Farmington, New Mexico public hearing, by mail, and by email.
Most postcards contained personalized hand-written comments but the comments did not provide
additional substance. These postcards were not posted to the electronic docket, but are part of the
record for this rulemaking and are retained in paper form in the EPA's office. The postcard reads
as follows:
I support U.S. Environmental Protection Agency (EPA) plan to install the Best
Available Retrofit Technology (BART) air pollution controls on Four Corners
Power Plant (FCPP). (Docket #EPA-R09-QAR-2010-0683). FCPP's emissions
are responsible for increased heart and respiratory diseases. I want
implementation of the most stringent pollution control technologically available,
and transition to Renewable Energy solution.
Comment 0196 includes 115 additional postcards submitted by Dine CARE containing the
printed text above, most with personalized hand-written comments but the comments did not
provide additional substance. In addition, Comment 0193 represents an example of 46 postcards
with the same printed text (most with personalized, non-substantive hand-written additions)
received pursuant to an effort by the Sierra Club.
Comment 0203 represents a mass comment campaign organized by the National Parks
Conservation Association, which was submitted essentially verbatim by 9,312 commenters. The
comment reads as follows:
Dear Lee,
As someone who is proud of our country's national parks, I am writing to thank
you for your recent steps to reduce the air pollution from the Four Corners Power
Plant—and also to urge you to do better. I ask that you protect the people and
parks of the Southwest region by requiring the Four Corners plant to emit less
pollution. Without meaningful reductions in air pollution, Four Corners Power
Plant will continue to obscure the views that make these parks icons of the
western landscape.
I support the agency's decision to propose the retirement of units 1, 2, and 3 and
the pollution control technology—Selective Catalytic Reduction—as a cost
effective way to significantly cut down on haze pollution from the other two coal
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units. I urge EPA to lower its proposed numeric limits on nitrogen oxides and
particulate matter pollution, add limits for ammonia and sulfuric acid pollution,
and require compliance with these limits within three years in its final decision.
These limits would mean healthier air for us all, better views of our magnificent
national parks, and a stronger tourism economy. Your decision will be inhaled by
neighboring communities and park visitors for the life of the plant.
Please don't miss this opportunity to protect our people and parks by adequately
cleaning up the Four Corners Power Plant now.
Please work hard to protect one of my favorite places. We cannot let our natural
treasures be compromised.
Thank you for considering my request.
Comments 0116, 0203, 0204, and 0205 include an additional 204 comments that were
submitted via the National Parks Conservation Association campaign, most incorporating some
or all of the same points. Many of these added personal observations. However, of the four
comments included in Comment 0204, two did not support EPA's proposed actions, and two
were unrelated to this rulemaking.
Comment 0212 represents a mass comment campaign organized by the Sierra Club. Four
different versions of the campaign letter were submitted, with some variations to address
different areas in the Four Corners region.
One of the versions of the Sierra Club campaign email was submitted largely without
change by 1,218 commenters and reads as follows:
Dear EPA Administrator Blumenfeld,
I support the EPA's proposed rule on Best Available Retrofit Technology (BART)
for regional haze at the Four Corner's Power Plant. The diverse communities of
the Four Corners deserve cleaner air and a sustainable energy future that can only
be achieved by cleaning up dirty coal plants like the Four Corners Power Plant.
Thank you for helping everyone breathe easier by considering the two proposals
at hand, both of which will help to reduce emissions from the plant by installing
selective catalytic reduction controls.
By outlining a plan to justly transition Four Corners off coal as soon as reasonably
possible, we can bring a green economic boom to the region. I ask that these
further and necessary retrofits be made to reduce dangerous pollution in the area.
I am asking for the most stringent reduction in emissions to come out of these
proposals. The haze in the National Parks that are within 300 kilometers
(180 miles) of FCPP will see a significant improvement in visibility as a result of
this BART. It is important that we protect these precious and irreplaceable public
areas including Mesa Verde National Park just north of the plant. There are also
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many sacred Navajo sites in the vicinity that need to be considered here as well.
Tourism is a large economic contributor in the 4 Corners, and it is imperative that
we clean up this haze in order to preserve this sector.
The implementation of pollution controls in the form of Selective Catalytic
Reduction (SCR) will reduce Nitrous Oxide (NOx) pollution by 80-90%. NOx
pollution will be reduced by 16,000 tons per year, per the 2010 New Mexico
Environmental Department report. NOx pollution has been shown to have direct
negative health impacts. EPA includes 13 different health effects: adult and infant
premature mortality, chronic bronchitis, heart attack, acute bronchitis, upper and
lower respiratory symptoms, aggravation of existing asthmas, and hospital
admissions and or emergency room visits for COPD, pneumonia, asthma, and
cardiovascular diseases.
A U.S. Geological Survey study found that people living in Shiprock are more
than 5 times as likely to be seen at Indian Health Services for respiratory
complaints as are residents of other nearby communities.
Overall, we want the best plan to reduce emissions in the area and one that also
looks towards a transition to renewable energy in the near future.
Knowing the health, environmental and economic benefits of clean air, I am
asking for the most stringent reduction in emissions possible.
The second version of the Sierra Club campaign email was submitted essentially
verbatim by 341 commenters. This version reads as follows:
Dear EPA Region 9 Administrator Blumenfeld,
I support the EPA's proposed rule on Best Available Retrofit Technology (BART)
for regional haze at the Four Corner's Power Plant.
The diverse communities of the Four Corners deserve cleaner air and a
sustainable energy future that can only be achieved by cleaning up dirty coal
plants like the Four Corners Power Plant. Thank you for helping everyone breathe
easier by considering proposals that will help to reduce emissions from the plant
by installing air pollution controls.
I want these retrofits to be made to reduce dangerous pollution in the area.
Nitrogen oxide pollution has been shown to have direct negative health impacts
including adult and infant premature mortality, chronic and acute bronchitis, heart
attack, upper and lower respiratory symptoms, aggravation of existing asthma,
increased hospital and emergency room visits, pneumonia, asthma, and
cardiovascular diseases.
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A U.S. Geological Survey study found that people living in Shiprock, NM are
more than five times as likely to be seen at Indian Health Services for respiratory
complaints as are residents of other nearby communities.
Lowered emissions will help lessen these impacts on our community health and
also our natural places. Tourism is a large economic contributor in New Mexico,
and it is imperative that we clean up this haze in order to preserve this sector.
The haze in the national parks that are within 180 miles of FCPP will see a
significant improvement in visibility with retrofit technology implemented. It is
important that we protect these precious and irreplaceable public areas like
Bandelier National Monument near Los Alamos, Pecos Wilderness near Santa Fe,
Wheeler Wilderness near Taos and San Pedro Parks near Cuba.
Knowing the health, environmental and economic benefits of clean air, I am
asking for the most stringent reduction in emissions possible.
The third version of the Sierra Club campaign email was submitted largely without
change by 184 commenters and reads as follows:
Dear EPA Region 9 Administrator Blumenfeld,
I support the EPA's proposed rule on Best Available Retrofit Technology (BART)
for regional haze at the Four Corners Power Plant. A reduction in air pollution
from the Four Corners Power Plant will protect the health of people living in Utah
and preserve the many national parks in our area.
I want these retrofits to be made to reduce dangerous pollution in the area.
Nitrogen oxide pollution has been shown to have direct negative health impacts
including adult and infant premature mortality, chronic and acute bronchitis, heart
attack, upper and lower respiratory symptoms, aggravation of existing asthma,
increased hospital and emergency room visits, pneumonia, asthma, and
cardiovascular diseases.
Lowered emissions will help lessen these impacts on our community health and
also our natural places.
The haze in the national parks that are within 180 miles of FCPP will see a
significant improvement in visibility with retrofit technology implemented. It is
important that we protect these precious and irreplaceable public areas like Bryce
Canyon National Park, Canyonlands National Park, Monument Valley Navajo
Tribal Park, and Arches National Park.
Knowing the health, environmental and economic benefits of clean air, I am
asking for the most stringent reduction in emissions possible.
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The diverse communities of the Four Corners deserve cleaner air and a
sustainable energy future that can only be achieved by cleaning up dirty coal
plants like the Four Corners Power Plant. Thank you for helping everyone breathe
easier by considering proposals that will help to reduce emissions from the plant
by installing air pollution controls.
The fourth version of the Sierra Club campaign email was submitted essentially verbatim
by 77 commenters. Version 4 reads as follows:
Dear EPA Region 9 Administrator Blumenfeld,
I support the EPA's proposed rule on Best Available Retrofit Technology (BART)
for regional haze at the Four Corner's Power Plant.
Coloradans deserve cleaner air and a sustainable energy future that can only be
achieved by cleaning up dirty coal plants like the Four Corners Power Plant.
Thank you for helping everyone breathe easier by considering proposals that will
help to reduce emissions from the plant by installing air pollution controls.
I want these retrofits to be made to reduce dangerous pollution in the area by 80-
90% of the biggest source of smog causing Nitrogen oxide in the nation. Nitrogen
oxide pollution has been shown to have direct negative health impacts including
adult and infant premature mortality, chronic and acute bronchitis, heart attack,
upper and lower respiratory symptoms, aggravation of existing asthma, increased
hospital and emergency room visits, pneumonia, asthma, and cardiovascular
diseases.
Lowered emissions will help lessen these impacts on our community health and
also our natural places. Tourism is a large economic contributor in Colorado, and
it is imperative that we clean up this haze in order to preserve this sector.
The haze in the national parks that are within 180 miles of FCPP will see a
significant improvement in visibility with retrofit technology implemented. It is
important that we protect these precious and irreplaceable public areas like Mesa
Verde National Park and the Weminuche Wilderness.
Knowing the health, environmental and economic benefits of clean air, I am
asking for the most stringent reduction in emissions possible.
Comment 0206 includes an additional 27 comments that were submitted via the Sierra
Club campaign, most incorporating some or all of the same points. Some of these commenters
described personal experience with worsening air pollution in the region, and others expressed
concern about negative impacts resulting from the use of coal to generate electricity.
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Comment 0215 represents a mass email campaign sponsored by WildEarth Guardians,
which was submitted essentially verbatim by 637 commenters. The comment reads as follows:
The Four Corners Power Plant poses significant threats to public health and
welfare. I urge you to do more to protect the Four Corners region from the
harmful impacts of its air pollution.
Please use your discretion to consider alternative air pollution control strategies
that better protect the environment. Wind and solar are both plentiful in the Four
Corners region. Importantly, these energy sources do not poison waters, create
smog, or foul the air quality in our most treasured National Parks and Wilderness
Areas.
You have the discretion to do more than require retrofits. You have the discretion
to power the Four Corners Power Plant past coal.
The opportunities for a healthy environment are enormous in the Four Corners.
Please help make this a reality. For the future of our communities, our wild lands,
and the Western United States, please consider alternatives to coal.
Comment 0207 includes an additional 27 comments that were submitted via the
WildEarth Guardians campaign, most incorporating some or all of the same points. Several of
these commenters expressed concern about the negative effects of using coal as an energy
source, and some included personal experiences with air pollution in the area. However, one of
the commenters expressed support for retrofitting FCPP, indicating that alternative energy
sources cannot meet our energy needs today.
Response:
EPA agrees with commenters that SCR is BARTfor FCPP and we are finalizing our
proposal as such. EPA also agrees with commenters that the proposed andfinal NOx emission
limit proposed will reduce haze and improve visibility in the Four Corners region and for the
broader Colorado Plateau. EPA is also giving the owners of FCPP the option to implement the
alternative emission control strategy in lieu of BART that will result in greater emission
reductions of NOx and other air pollutants.
Regarding comments on public health, EPA notes that the same pollutants that impair
visibility are a concern for human health; therefore reducing the NOx emissions contributing to
haze should also improve air quality generally in this area.
While many commenters expressed a desire for EPA to encourage a transition to
renewable energy technologies such as wind and solar power, the ability to require such a
transition is beyond the scope of this rulemaking. As described in a previous response, EPA does
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not consider BART as a requirement to redesign a source when considering available control
alternatives (see specifically 70 FR 39164).15
15 See "Regional Haze Regulations and Guidelines for Best Available Retrofit Technology (BART)
Determinations", 70 FR 39104, July 6, 2005, in the docket for this rulemaking
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3.0 Comments on Factor One - Cost of Controls
3.1 Comments on the Analysis of the Cost of SCR at FCPP
Comment:
Some of the owners of FCPP (0168, 0174, 0176/0177, 0185), the Navajo Nation (0223),
and a utility industry association (0187) stated that in analyzing the cost of SCR at FCPP, EPA
improperly reworked and reduced the SCR cost estimates submitted for FCPP by eliminating
line item costs that are not explicitly included in the EPA Control Cost Manual (citing 75 FR
64227). According to the commenters, the BART rules make clear that the cost analysis should
take into account any site-specific design or other conditions that affect the cost of a particular
BART technology option (often citing 70 FR 39166). In addition, the commenters generally
stated that the significance of considering site-specific cost information was emphasized in the
D.C. Circuit's American Corn Growers decision, where the court observed that each of the
statutory factors in any BART determination, specifically including the cost of the technology,
must be addressed "on a source-by-source basis." Am. Corn Growers Ass 'n v. EPA, 291 F.3d 1, 6
(D.C. Cir. 2002). Two of the commenters (0176/0177, 0187) indicated that this principle is
further affirmed in the BART rules, which state that "one or more of the available control
options may be eliminated from consideration because they are demonstrated to be technically
infeasible or to have unacceptable energy, cost, or non-air quality environmental impacts on a
case-by-case (or site-specific) basis" (citing 70 FR 39164). Three of the commenters (0185,
0187, 0223) noted that the BART rules make the nonbinding nature of the EPA Control Cost
Manual clear (citing 70 FR 39127 and footnote 15).
Two of the commenters (0168, 0176/0177) defended the SCR cost estimate submitted for
FCPP, noting that the estimate was prepared by B&V, an engineering firm with extensive
experience with the installation and operation of pollution control equipment. The commenters
noted that B&V performed a detailed analysis of the FCPP units and considered site-specific
conditions that preclude the use of the general ratios or other factors that can be derived from the
EPA Control Cost Manual. According to the commenters, B&V followed the EPA Control Cost
Manual to estimate annual costs, but also followed accepted guidelines for control technology
analyses by using actual SCR retrofit data from facilities with over 10,000 MW of generation for
which B&V completed the designs. One of these commenters (0176/0177) indicated that the
prices used in the cost analysis were based on quotes from equipment vendors that reflected
current pricing.
Since issuance of the Advanced Notice of Proposed Rulemaking (ANPR) for the FCPP
FIP rulemaking, one of the commenters (0176/0177) commissioned B&V to review its cost
assumptions and EPA's cost-related comments in the ANPR, and the commenter submitted a
copy of B&V's report with its comments. According to this B&V report, the costs of SCR
systems at FCPP are further escalated due to the complex constructability issue resulting from
the constrained site arrangements. The report further notes that extensive modifications to
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existing ductwork and boiler steel would be required and provides specific examples where the
EPA Control Cost Manual does not account for the site-specific costs of installing SCR.16
This commenter (0176/0177) indicated that as a further check on the cost estimates, the
commenter retained the Shaw Group to conduct an independent review of the cost assumptions
and EPA's comments in the ANPR, and the commenter also submitted this report. The Shaw
Group's report notes that the background section of the EPA Control Cost Manual states that the
Manual is not suitable for use with Electric Generating Units (EGUs) because of differences in
accounting for utility sources. This report also states that the results of the EPA Control Cost
Manual are relatively generic, and that customizing the analysis with industrial sources of
information may lead to a more accurate estimate.
The commenter (0176/0177) noted that EPA stated in the proposed FIP that it "has
generally accepted the costs estimates APS submitted," but has "eliminated any line item costs
that are not explicitly included in the EPA Control Cost Manual' (citing 75 FR 64227). The
commenter asserted that EPA provided no justification for excluding these costs, and that no
justification for doing so exists.
The commenter (0176/0177) concluded that the analyses conducted by B&V and the
Shaw Group are sound, and the Shaw Group's report confirms that the inclusion of these types of
costs is entirely appropriate. According to the commenter, it is improper and unlawful for EPA to
eliminate consideration of these site-specific cost factors. The commenter asserted that because
the proposed BART FIP rule is fundamentally inconsistent in this respect with EPA's own rules
and with the CAA, as construed by the D.C. Circuit in American Corn Growers, and because
EPA has found the submitted cost estimates "generally acceptable]" (citing 75 FR 64227)
without providing any sound or lawful rationale for rejecting or revising those estimates, there is
no basis for EPA not to use those estimates.
Another of the commenters (0185) concluded that a BART determination cannot properly
be made until EPA accepts or conducts a cost analysis, such as the one presented by APS, that
complies with the law. A third commenter (0187) concluded that EPA's proposed cost analysis is
inconsistent with the D.C. Circuit's decision in American Corn Growers and with the governing
rules and is therefore unlawful. The Navajo Nation (0223) concluded that EPA's compliance
costs are inaccurate and flawed.
Response:
EPA disagrees with the comment that EPA improperly reworked and reduced the SCR
cost estimates. EPA used a hybrid approach for our cost analysis that relied primarily on the
cost estimates provided by APS, but also followed the BART Guidelines, that state "[i]n order to
maintain and improve consistency, cost estimates should be based on the OAQPS Control Cost
16 EPA notes that this report was considered and discussed in the TSD for our proposed rulemaking, and was
included in our docket. The revised cost estimates submitted to EPA subsequent to our ANPR were actually lower
than the cost estimates submitted prior to our ANPR.
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Manual, where possible " 77, to determine whether APS included cost estimates for services or
equipment associated with SCR that were either not needed (e.g., mitigation for increased
sulfuric acid emissions or catalyst disposal), or not allowed under the EPA Control Cost Manual
(e.g., owner's costs). We note that the EPA cost estimate presented in the TSD ($718 million
total for Units 1-5) is 18% lower than the highest B&V cost estimate and less than 0.6% lower
than the most recent B&V cost estimate APS submitted to EPA in 2010.
The cost analysis we presented in the TSD18 and supporting documents19 for our October
2010 proposed BART determination was based on the cost estimate updates prepared by B&V
for APS dated August 19, 2008 and submitted by letter dated March 16, 2009.20 In the TSD (see
page 30), we explain that APS submitted an additional, more refined update to the cost estimates
by letter dated April 22, 2010, but that submittal was labeled as Confidential Business
Information. On September 9, 2010, APS confirmed that it did not consider this B&V report to
be confidential and EPA included this updated cost analysis in our docket21 and discussed it in
our TSD. We noted in our TSD that the revised cost estimates for SCR submitted by APS in 2010
($722 million total for Units 1-5) were lower for all units compared to the cost estimates
submitted by APS in March 2009 ($874 million total for Units 1 - 5).
Our SCR cost analysis relied primarily on the highest cost estimates submitted by APS
(dated August 19, 2008 and submitted March 16, 2009). EPA accepted all site-specific costs
provided by APS cost categories (e.g., purchased equipment, installation) that are typically
included in a cost estimate conducted in accordance with the EPA Control Cost Manual, and
only excluded line item costs that are not explicitly included in the EPA Control Cost Manual or
in a limited number of cases where EPA determined alternative costs were more appropriate or
where APS did not provide sufficient explanation to justify different costs (e.g., costs of catalysts,
interest rates). Therefore, we disagree with the commenters' assertion that our cost analysis did
not take into account the site-specific cost information supplied by APS. We again note that the
EPA cost estimate presented in the TSD ($718 million total for Units 1-5) is only 18% lower
than the highest B&V cost estimate and less than 0.6% lower than the most recent B&V cost
estimate APS submitted to EPA in 2010.
Our detailed, line-by-line analysis was included in the docket22 for this proposed
rulemaking and provided an explanation for why we retained, modified, or rejected each line
item in the SCR cost estimate for each of the five units at FCPP.
For example, APS provided site-specific estimates for individual components of the SCR
system, while the equations in EPA Control Cost Manual yield overall system costs. In the TSD
for our proposed rulemaking, we generally accepted the component costs estimated by B&V,
including such items as costly new preheaters and new induced draft andforced draft fans that
are not included in the EPA Control Cost Manual equations but were deemed by B&V to be
17 The OAQPS Control Cost Manual is now called the EPA Control Cost Manual. The EPA Control Cost Manual is
available from the following website: http://www.epa.gOv/ttncatcl/products.html#cccinfo.
18 "TSD Proposal - Technical Support Document 10-6-10", Document No. EPA-R09-OAR-2010-0683-0002.
19 "TSD ref [40] Four Corners SCR Cost Analysis (EPA) 8-26-10", Document No. EPA-R09-OAR-2010-0683-0033.
2° Submission to EPA 3-2009plus attachments", Document No. EPA-R09-OAR-2010-0683-0015.
21 "TSD ref [42] NOx Compliance Study", Document No. EPA-R09-OAR-2010-0683-0034.
22 "TSD ref [40] Four Corners SCR Cost Analysis (EPA) 8-26-10", Document No. EPA-R09-OAR-2010-0683-0033.
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necessary at FCPP due to retrofit considerations. However, we did not include the costs
includedfor variable frequency drives for the new fans, which are not requiredfor SCR, or the
costs for unspecified "miscellaneous equipment. " The cost estimate did not provide information
documenting the need for these line items or otherwise justifying their inclusion.
In addition, we used the EPA Control Cost Manual equations and a catalyst cost estimate
provided by a vendor of ultra low-oxidation catalysts to estimate the cost of the initial catalyst
(included under total capital costs) and replacement catalyst (included under total annual costs)
for our revised costs. This vendor cost was substantially less than the cost estimated by B&Vfor
the catalyst. In addition, typically, the vendor cost includes the disposal of the spent catalyst;
therefore, the catalyst disposal cost was not included as a separate line item in our revised costs
although it was included as an annual cost in the B&V cost estimate. We also applied what we
believe is a more realistic tax rate of 6 percent, rather than the 10 percent in the B&V estimate.
The state of New Mexico does not impose a sales tax; rather, New Mexico applies a gross
receipts tax on businesses and services in New Mexico.23 New Mexico reports that this tax varies
throughout the state from 5.125% to 8.6875%. EPA 's use of a 6% tax rate is generally consistent
with the tax rate the New Mexico Environment Department (NMED) applies in its emission
control cost estimates of 6.2% to account for the gross receipts tax.24
Using Units 4 and 5 (which had identical cost estimates in the 2008 B&V estimates) as
examples, other notable line items in the estimated Total Capital Investment in the APS submittal
that we did not include in our cost analysis are "owners costs ", "side effect mitigation ", and
"lost revenue
• "Owners cost" was described by the commenters as typical expenditures that an owner
will experience during an air quality control retrofit project, such as costs for project
development, financing, project management, plant startup/construction support, and
taxes/advisory fees/legal. The commenters calculated these costs at 3 percent of the Total
Direct Cost for the units. As such, these estimates do not truly represent a site-specific
consideration of such costs. The commenters did not provide any documentation specific
to FCPP or SCR. In addition, such costs are not included in the EPA Control Cost
Manual. Therefore we exclude this cost of $5.6 million in our revised cost estimate.
• "Side effect mitigation " was referred by the commenters as additional measures included
to reduce emissions of SO 3 at a cost of $7 million. However, EPA calculated catalyst cost
based on the use of an ultra low oxidation catalyst, so we do not agree that such side
effect mitigation measures are needed.
• "Lost revenue " of $14.4 million was estimated by the commenters for an "extended
outage. " APS did not provide sufficient information for EPA to determine that SCR
equipment could not be installed during scheduled outages and we excluded this cost in
our revised cost estimate.
23 http://www.tax.newmexico.gov/All-Taxes/Pages/Gross-Receipts-Tax.aspx.
24 Personal communication between Elizabeth Bisbey-Kuehn, NMED and Anita Lee, EPA Region 9. September 2,
2011. See "Memo to file 9-2-11 voicemail from NMED.docx" in the docket for this final rulemaking.
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It should be noted that in the revised cost estimates submitted by APS in 2010, B&V no
longer included side effect mitigation and significantly reduced estimated taxes and lost revenue.
For Unit 4 the total for these three cost elements fell from about $37.8 million to only $4.3
million in the 2010 APS submittal. The updated Total Capital Investment estimates for Units 4
and 5 in the 2010 submittal averaged about $212.5 million, which is slightly lower than our
revised cost estimate of $217.7 million for each unit.25 The refined Total Capital Investment
estimates in the 2010 submittal for Units 1-3 remained slightly higher (about 2 to 7 percent) than
our revised cost estimates based on the 2009 submittal. The general agreement between the 2010
B&V refined cost estimates and EPA 's cost estimates suggests that our BART determination
would not be substantially different if we had relied instead solely on B&V's 2010 cost estimates
for FCPP because the cost effectiveness values would be similar.
In terms of annual cost estimates, the difference between the APS submittals (2009 and
2010) and our revised cost estimates is larger. The annual costs for Units 4 and 5 in the 2009
APS submittal are nearly twice the amount of EPA 's revised cost estimate even though our
revised capital cost estimate is only 18 percent less than the B&V estimate.
The large difference in annual costs results mainly from differing assumptions used in the
"capital recovery " estimates, which account for over three fourths of the overall difference
between APS and EPA estimated annual costs. Capital recovery reflects the effective annual cost
to the facility of borrowing the capital to pay for the SCR system. This element of annual cost is
the product of the Total Capital Investment and the Capital Recovery Factor (CRF). The CRF, in
turn, is calculated using a formula based on the assumed interest rate and equipment life.
In its cost estimates for APS, B&V assumed an interest rate of 15% and an equipment life
of 20 years. While we also assumed an equipment life of 20 years, we based our CRF on an
interest rate of 7%. The 15% interest rate used by APS to calculate capital recovery for the SCR
installation is too high. For cost analyses related to government regulations, an appropriate
"social" interest (discount) rate should be used. The latest real interest rate for cost
effectiveness analyses published by the Office of Management and Budget (OMB) is 2.8% for a
20 year period (Revised January 2008). EPA calculated capital recoveries using 3% and 7%
interest rates in determining cost effectiveness for the Regulatory Impact Analysis (RIA) for the
Guidelines for BART Determinations under the Regional Haze regulations.26 Therefore, we used
a conservative approach to calculate the capital recovery in our revised cost analysis using an
interest rate of 7% and an equipment life of 20 years.
The APS submittal provided no justification for what appears to be an inflated interest
rate (15%) in this period of historically low rates, and our interest rate of 7% is appropriately
conservative for this cost analysis and consistent with the most conservative interest rate used in
the RIA for the BART Guidelines. The other major contributors to the difference in annual cost
25 "APS Submission to EPA 4-22-10 plus Attachments", Document No. EPA-R09-OAR-2010-0683-0016. In the
2010 APS submittal, B&V prepared separate estimates for Units 4 and 5 for the first time. Certain common
equipment that would be shared by the two units was included in the capital costs for Unit 4, with the result that
Total Capital Investment was estimated at about $223.8 million and $201.3 million for Units 4 and 5, respectively.
26 Regulatory Impact Analysis for the Final Clean Air Visibility Rule or the Guidelines for Best Available Retrofit
Technology (BART) Determinations Under the Regional Haze Regulations, EPA-0452/R-05-004, June 2005.
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estimates between the APS 2009 submittal and our revised cost estimate are maintenance labor
and materials (8% of the difference), costs related to catalyst replacement (13%), and the
difference between estimates of Total Capital Investment (also a factor in determining annual
capital recovery -16%).
The difference between estimates of maintenance labor and materials is primarily related
to the method of calculation, but is also affected by the difference in capital cost estimates. In
our revised cost estimate, we applied the methodology specified in the EPA Control Cost Manual
which determines this annual cost as 1.5% of the Total Capital Investment. In the 2009 APS
submittal, this cost element is estimated as 3% of Total Direct Costs (a subset of Total Capital
Investment). APS did not provide sufficient information to justify its estimate that maintenance
labor and materials would be 3% of Total Direct Costs.
As previously discussed, we determined the cost of initial catalyst and replacement
catalyst based on the EPA Control Cost Manual methodology and a quote from a vendor for
ultra low-oxidation catalyst that included spent catalyst disposal. The cost estimate prepared by
B&Vfor the 2009 APS submittal included a significantly higher catalyst cost, used a different
methodology for determining the annual cost of catalyst replacement, and included a separate
cost for catalyst disposal. Again, APS did not provide sufficient information to justify the
assumption that costs for spent catalyst disposal would be separate from the catalyst cost.
As noted above, in 2010 APS submitted an updated, refined cost estimate prepared by
B&V. As discussed, this submittal included estimates of Total Capital Investment for Units 4 and
5 that were, on average, lower than our revised cost estimate for these units. Despite this fact,
the average annual cost estimated by B&Vfor these two units ($41.8 million) exceeded our
estimate ($28.4 million) by 45%. This difference is entirely due to the CRF used in the B&V
calculations, which was again based on an assumed interest rate of 15%.27 As explained
previously, the interest rate that we used in our calculations (7%) is in itself conservative and is
more appropriate for these calculations than the high rate used by APS/B&V.
In addition, we disagree with the commenters' assertion that our analysis is not
consistent with the D.C. Circuit's American Corn Growers decision. As noted, we incorporated
site-specific cost information provided by APS where documented and justified. In addition, we
27 In the 2010 submittal for Units 4 and 5, B&V very significantly reduced the estimate for maintenance labor and
materials and somewhat reduced the estimate for catalyst replacement and spent catalyst disposal. Although this
estimate included some line items not included in their earlier estimate or our cost estimate (such as yearly
emissions testing and fly ash sampling and analysis), the total of all annual costs other than capital recovery was less
than our estimate for this class of costs. Thus, for Units 4 and 5 the entire excess annual cost in the 2010 submittal
can be ascribed to the CRF and the interest rate used to calculate it. For Units 1-3, the estimates of annual costs
submitted by APS in 2010 exceed our estimates by from 65 to 73% even though their Total Capital Investment
estimates exceed ours by only 2 to 7%. While the CRF, with its high underlying interest rate, is the predominant
cause for the differences between these annual cost estimates, it is not the sole cause. Because Total Capital
Investment is a factor in the calculation of capital recovery, the slightly higher estimates are a small factor for Units
1-3. In addition, the non-capital recovery annual costs estimated for these units in the 2010 submittal continue to
exceed our estimates, primarily due to maintenance labor and materials and catalyst replacement and disposal costs
(which were not reduced from the 2009 submittal for these units). Nevertheless, the value of the CRF accounts for
over three quarters of the difference between the estimate of total annual costs in the 2010 APS submittal and our
estimate.
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do not agree that use of the EPA Control Cost Manual alone necessarily constitutes a failure to
conduct a cost analysis on a source-specific basis. The costing methodology in the EPA Control
Cost Manual requires as input certain source-specific design characteristics and, therefore, the
results are a source-specific estimate of costs.
Regarding the Shaw Group report's comment on the statement in the EPA Control Cost
Manual about its suitability for use with EGUs, we believe that the text of the Manual was
improperly taken out of context. The relevant text of the EPA Control Cost Manual— reads as
follows:
... this Manual does not directly address the controls needed to control air
pollution at electrical generating units (EGUs) because of the differences in
accounting for utility sources. Electrical utilities generally employ the Electric
Power Research Institute (EPRI) Technical Assistance Guidance (TAG) as the
basis for their cost estimation processes.1
1 This does not mean that this Manual is an inappropriate resource for utilities. In
fact, many power plant permit applications use the Manual to develop their costs.
However, comparisons between utilities and across the industry generally employ
a process called "levelized costing" that is different from the methodology used
here.
Thus, the full text of the Manual indicates that it is an appropriate resource for utilities,
and that many power plant permit applications have used the EPA Control Cost Manual to
develop their costs. In any case, we generally used equipment and labor costs provided in the
APS cost estimate, except for those line items that we believed to be unjustified or unreasonable.
Comment:
One of the owners of FCPP (0174) stated that EPA's discussion of costs associated with
BART determinations for other Western power plants is misleading (citing page 32 of the TSD
for EPA's proposed BART determination for FCPP). According to the commenter, EPA
provides a number of examples of cost estimates developed by other Western power plants for
installation of SCRs, but does not mention that in most of those cases, the permitting authorities
rejected SCR and proposed combustion controls as BART. Furthermore, the commenter
indicated that because none of those power plants have installed SCRs, the referenced estimates
are not based on actual construction and operating costs.
Response:
EPA disagrees with the commenter that our discussion of estimated costs in Table 16 of
our TSD was misleading. Recent BART determinations have proposed and/or finalized SCR (San
90
"EPA Air Pollution Control Cost Manual". Sixth Edition, Document No. EPA/452/B-02-001, January 2002. Pg.
1-3. Available at http://www.epa.g0v/ttncatcl/pr0ducts.html#cccinf0
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Juan Generating Station Units 1-4, Naughton Unit 3, Jim Bridger Units 1 and 2) or selective
non-catalytic reduction (SNCR) (M.R. Young Units 1 and 2, Centralia Units 1 and 2).29 EPA
determined that the comparisons of these SCR costs are appropriate because they are based on
recent BART cost estimates submitted by the power plants.
The commenter is correct in noting that the SCR cost effectiveness estimates included in
the TSD represented cost estimates rather than actual construction and operating costs. The
table was meant to compare the estimated cost effectiveness values for FCPP with other recent
SCR BART cost estimates provided by coal fired electric generating facilities in the Western
United States, and was not intended to show the final cost effectiveness of actual SCR
installations. EPA notes that actual construction and operating costs for these facilities are not
yet available, and will not be available until these BART determinations are finalized and
facilities have completed installation of its BART controls.
Comment:
One of the owners of FCPP (0176/0177) noted that EPA selected combustion controls as
presumptive BART for EGUs like FCPP because those controls are "more cost effective than
post-combustion controls such as SCRs" (citing 70 FR 39134). According to the commenter,
EPA's analysis at that time for setting presumptive BART limits found that the cost effectiveness
of combustion controls averaged less than $600 per ton of NOx removed, while SCR averaged
more than $1,600 per ton.
The commenter's (0176/0177) most recent cost analysis estimated that the average cost
effectiveness of combustion controls for the five units at FCPP would range from $524 to $1,735
per ton of NOx removed, while the average cost effectiveness of SCR would range from $4,215
to $5,283 per ton. The commenter also noted that EPA's estimate of average cost effectiveness
for SCR at FCPP ranged from $2,515 to $3,163 per ton. The commenter stated that, at the low
end, only the estimate of the average cost effectiveness of combustion controls is in line with
EPA's estimates of cost-effective controls, while the estimate of average cost effectiveness of
SCR is significantly higher. Another one of FCPP's owners (0168) also made this last point.
The commenter (0176/0177) asserted that there is no basis for EPA to depart from its
own rules by concluding that SCR is BART for FCPP when this technology is many times more
expensive than the EPA-determined cost effective level of controls for presumptive BART and
costs far more than the levels EPA rejected as cost-ineffective for presumptive BART. The
commenter contended that EPA's disregard for its own cost effectiveness determination in the
BART rules renders the concept and importance of the "cost effectiveness" BART factor
meaningless.
Response:
29 See 76 FR 52388, August 22, 2011; 77 FR 33022, June 4, 2012; 77 FR 20894, April 6, 2012; 77 FR 30473, May
23,2012
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EPA disagrees with this comment. Although the commenters argue that the BART
Guidelines established a thresholdfor cost effectiveness against which future BART
determinations must compare, the BART Guidelines did not establish a cost effectiveness
thresholdfor all BART determinations. In developing the presumptive N0X limits for BART in
2005, EPA did not set the cost effectiveness values estimatedfor combustion controls as the
thresholdfor determining whether a given control technology was or was not cost effective. If
EPA had intended the cost effectiveness values estimated in 2005 to represent a thresholdfor
BART, it is reasonable to assume that the BART Guidelines would have included those cost
effectiveness values as thresholds in Appendix Y, and would have required future cost estimates
to be presented in 2005 dollars to appropriately compare against those thresholds. The BART
Guidelines do not set a numerical definition for "cost effective ", and the analysis ofpresumptive
limits uses cost effectiveness as a means to broadly compare control technologies, not as
thresholdfor rejecting controls for an individual unit or facility that exceed the average cost
effectiveness of combustion controls.
Additionally, a comparison of the average cost effectiveness estimates in the 2005 BART
Guidelines against our cost effectiveness estimates for FCPP is not an "apples to apples "
comparison. The technical support documentation for the 2005 BART Guidelines30 indicate that
cost effectiveness of controls was not determined based on site-specific cost estimates developed
for each BART-eligible facility; rather cost estimates were determined using assumptions for
capital and annual costs per kilowatt (kW)31 or kilowatt-hour (kW-hr), and then scaled
according to boiler size. The supporting information for the 2005 BART Guidelines estimate
SCR costs for Units 4 and 5 at FCPP (capital cost = $64 million, total annual cost = $11
million) that are comparable to SCR cost estimates that were generated by NPS using the EPA
Control Cost Manual (capital cost = $53 million, total annual cost = $10 million32). The same
commenters have previously dismissed the NPS SCR cost estimates based on the EPA Control
Cost Manual as being too low because it does not include site-specific costs.33 The commenter
appears to be selectively choosing to accept the EPA Control Cost Manual in one case (cost
effectiveness of presumptive controls to serve as a bright line threshold), and reject it in another
(cost effectiveness of post-combustion controls at FCPP): on one hand, the commenter rejected
the EPA Control Cost Manual in favor of its own site-specific cost estimates because the EPA
Control Cost Manual is unrealistically low, and on the other hand, the commenter uses the
30 The technical supporting information is included in the docket for the final rulemaking for the BART Guidelines
(EPA-HQ-OAR-2002-0076) and includes several documents supporting the presumptive NOx limits finalized in the
BART Guidelines: (1) "Technical Support Document - Methodology for Developing BART NOx Presumptive
Limits" dated June 15, 2005 (document no. EPA-HQ-OAR-2002-0076-0445), and (2) "Technical Support
Document for BART NOx limits for Electric Generating Units Excel Spreadsheet", dated June 15, 2005 (document
no. EPA-HQ-0AR-2002-0076-0446).
31 In the 2005 BART presumptive limit analysis, EPA estimated capital cost assuming SCR cost = $100/kW.
32 See Table 9 in the October 2010 TSD for the proposed BART determination for FCPP. In its comments on the
ANPR, NPS revised its cost estimates for SCR on Units 4 and 5 to $114 million (capital cost) and $18 million (total
annual cost) - see Table 12 in the TSD for the proposed BART determination. Document no. EPA-R09-OAR-2010-
0683-0002.
33 In the ANPRM, in addition to reporting APS's cost estimates and EPA's revisions to APS's cost estimates, for
reference, EPA also reported cost estimate analysis conducted by NPS and provided to EPA during consultations
with the FLMs prior to our ANPRM. APS and other entities provided comments to EPA on the NPS cost estimates
reported in the ANPRM, see document titled "Comments on ANPRM 09 0598 APS Comments and Exhibits"
document ID number EPA-R09-OAR-2009-0598-0195.
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unrealistically low value from the EPA Control Cost Manual as a threshold to reject post-
combustion controls because its site-specific cost estimates are higher. In short, the commenter 's
recommendation to use generalized cost estimates from the 2005 BART Guidelines as a bright
line thresholdfor comparison with site-specific 2010 cost estimates is inconsistent with its own
criticisms of the EPA Control Cost Manual.
EPA notes that the average cost effectiveness of combustion controls cited by the
commenters in the development of the 2005 presumptive N0X limits (less than $600 per ton) was
calculatedfrom national total annual costs divided by the national reductions expected from
combustion controls. In the same technical documentation for the 2005 presumptive N0X limits,
if considered unit by unit at each BART-elisible facility, the average cost effectiveness of
combustion controls was estimated to be $1,790 per ton (nearly three times higher than average
cost effectiveness calculatedfrom total national annual costs and total national N0X reductions),
with a very large range of $100per ton to $70,000per ton, indicating that despite using
combustion controls to set presumptive N0X limits, combustion controls will not be cost effective
for all facilities - highlighting the needfor site-specific 5-factor analyses in determining BART.
If, in assessing our BART determination for FCPP, EPA relied strictly on the cost
effectiveness values in the 2005 BART Guidelines, as suggested by commenters, the Excel
Spreadsheet provided as technical support to the presumptive N0X limits suggests cost
effectiveness of combustion controls on Unit 5 at FCPP to be $1,716 per ton, SCR to be just over
$1,000 per ton on Units 4 and 5, and ROFA to be over $500 per ton. These estimates are
strongly dependent on the assumed efficiency of the control technology, but if taken at face
value, suggest that of the three options, ROFA would be most cost effective at FCPP, SCR is
second most cost effective, and combustion controls are the least cost effective. It is notable that
B&V, in its BART analysis conducted for FCPP, excluded ROFA for Units 4 and 5 because it
has not been demonstrated on large units, thus leaving SCR as the most cost effective control for
Unit 5 at FCPP according to the 2005 BART Guidelines.
Comment:
A number of commenters, including owners of FCPP (0168, 0174, 0176/0177) and a
utility association (0169), stated that EPA's BART analysis for FCPP was inconsistent with its
own regulations in that it failed to consider control costs as a function of visibility improvement.
These commenters (0168.1, 0169.1, 0174, 0176/0177) typically stated that EPA's BART
determination for FCPP must consider the cost effectiveness of control technology options in
terms of dollars per deciview-improved.
Some of the commenters (0174, 0176/0177) pointed out that the American Corn Growers
decision indicates that the CAA requires the consideration of control cost to include the degree
of improvement in visibility that would result from control. American Corn Growers, 291 F3d at
6-7. One commenter (0176/0177) added that the BART rules encourage the use of a dollars-per-
deciview-improved metric in addition to the dollars-per-ton-reduced metric (citing 70 FR
39170).
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This commenter (0176/0177) indicated that this is an important measure of cost
effectiveness which EPA failed to consider. The commenter stressed that before EPA proceeds
further with this rulemaking, it must analyze the average and incremental cost effectiveness of
the full range of control options on not only a dollar-per-ton-reduced but also a dollar-per-
deciview-improved basis.
Response:
The BART Guidelines require that cost effectiveness be calculated in terms of annualized
dollars per ton of pollutant removed, or $/ton.34 The commenters are correct in that the BART
Guidelines list the $/deciview ratio as an additional cost effectiveness metric that can be
employed along with $/ton for use in a BART evaluation. However, the use of this metric further
implies that additional thresholds or notions of acceptability, separate from the $/ton metric,
would need to be developedfor BART determinations. We have not used this metric for BART
purposes because (1) it is unnecessary in judging the cost effectiveness of BART, (2) it
complicates the BART analysis, and (3) it is difficult to judge. In particular, the $/deciview
metric has not been widely used and is not well-understood as a comparative tool. In our
experience, $/deciview values tend to be very large because the metric is based on impacts at
one Class I area on one day and does not take into account the number of affected Class I areas
or the number of days of improvement that result from controlling emissions. In addition, the use
of the $/deciview suggests a level of precision in the CALPUFF model that may not be
warranted. As a result, the $/deciview can be misleading. We conclude that it is sufficient to
analyze the cost effectiveness of potential BART controls using $/ton, in conjunction with an
assessment of the modeled visibility benefits of the BART control.
EPA considered cost of controls by discussing the total capital costs, annual costs, and
$/ton of NOx pollution reduced. Additionally, in response to comments received on our proposal,
EPA included calculations and consideration of incremental cost effectiveness (see Section 3.2 of
the Response to Comments document in the docket for this final rulemaking). EPA considered
visibility impacts by discussing the deciview improvement resulting from controls, as well as the
percent change in improvement. EPA determined that these metrics are sufficient in completing
our five-factor analysis for FCPP.
Comment:
One environmental advocacy group (0182) who favors assessing cumulative visibility
impact and benefit across multiple Class I areas (see Section 7.0) argued that it is a more
accurate depiction of costs to use a dollars-per-deciview-improved on a cumulative basis than to
use a cost/ton basis standing alone. The commenter asserted that this metric provides a
mechanism to ascribe meaningful value to pollution controls that would benefit numerous Class I
areas.
Response:
34 70 FR 39167
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EPA disagrees with the commenter that a $/dv or $/cumulative dv metric is a more
accurate depiction of costs than the $/ton metric. While a $/dv metric and a $/cumulative dv
metric may provide some useful information to assess how pollution controls would benefit
numerous Class I areas, as described in the response to the previous comment on use of the $/dv
metric, the BART Guidelines do not require consideration of $/dv as a mandatory metric in a
BART analysis. EPA considered cost of controls by discussing the total capital costs, annual
costs, $/ton, and incremental $/ton (See Section 3.2), and considered visibility impacts by
discussing the individual and cumulative deciview improvement resulting from SCR, as well as
the percent change in improvement.
Comment:
One commenter (0117), who stated that BART must be determined in the context of
reasonable progress rather than in isolation (see Section 10.0 for more on the commenter's legal
arguments), stated that the cost effectiveness metric used by EPA (i.e., $/ton of NOx reduced)
does not satisfy the statutory requirement to consider the cost to comply with the Regional Haze
program because it does not include compliance costs related to requirements for reasonable
progress.
Response:
Congress identified BART as a key measure for ensuring reasonable progress. We
disagree that BART must be determined in the context of reasonable progress. If anything,
reasonable progress depends on BART. Because the Class I areas affected by emissions from
FCPP are not achieving the glidepath, it is important that states, tribes, and EPA require
reasonable measures to be implemented to ensure that progress is made towards the national
visibility goal. The BART Guidelines specify that the cost of controls be estimated by identifying
the emission units being controlled, defining the design parameters for emission controls, and
developing a cost estimate based on those design parameters using the EPA Control Cost
Manual while taking into account any site-specific design or other conditions that affect the cost
of a particular BART control option. The BART Guidelines do not require the BART costs of
compliance to consider costs associated with reasonable progress.
EPA disagrees that there is a statutory requirement for a BART analysis to consider the
cost to comply with the Regional Haze program as a whole. In the Regional Haze provisions of
the Clean Air Act (§169A - Visibility Protection for Federal Class I Areas), Section 169A(g)
defines the determination of reasonable progress (§169A(g)(l)), separately from the
determination of BART (§169A(g)(2)). In determining reasonable progress, the costs of
compliance for a source subject to such requirements must be considered, and in determining
BART, the costs of compliance from the use of such technology must be considered. Because the
definitions for determining reasonable progress and BART are mutually exclusive, the statute
does not require a cost analysis for a BART determination to include costs associated with
reasonable progress.
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Comment:
The Navajo Nation (0223) stated that EPA should analyze the affordability of controls
under the supplemental proposal. The commenter noted that APS did not provide cost
information for its proposed alternative, and EPA did not perform a detailed cost analysis. The
commenter stated that EPA should perform a detailed analysis, rather than an approximation, of
the cost of compliance for installing SCR on Units 4 and 5, including a consideration of the
impacts of closing Units 1-3. The commenter suggested that line item costs should be provided
for Units 4 and 5, taking into account the change in business structure and the demand for
construction, labor, market, and material costs. The commenter cautioned that EPA and NPS
should not use "outdated" sources that may underestimate compliance costs (see the comments
above on the original cost analysis for BART) for this analysis or analyses for NGS or other
coal-fired plants in the region that contribute to regional economies.
Response:
EPA disagrees with the commenter that we should perform a detailed cost analysis of the
alternative emission control strategy, put forth in the supplemental proposal. APS did not
provide any indication to EPA that the costs of installing SCR on only Units 4 and 5 under the
alternative emission control strategy would significantly differ from the costs to install SCR on
only Units 4 and 5 under BART.
EPA does not agree that the affordability (as a business decision for the owners) of the
supplemental proposal for APS and other owners must be analyzed. Because APS, on behalf of
all owners, suggested to EPA this BART Alternative35, EPA has no reason to believe that APS or
the other owners may not be able to afford this option. Additionally, the affordability of
installing controls is not a required element of a cost analysis for BART in the BART Guidelines,
but may be considered in selecting the "best" alternative if "There may be unusual
circumstances that justify taking into consideration the conditions of the plant and the economic
effects of requiring the use of a given control technology 36 EPA conducted an affordability
analysis for our proposed BART determination to assess whether the cost to produce electricity
at FCPP would remain competitive compared to the market costs to purchase power if SCR were
required on Units 1 - 5 at FCPP. The goal of this analysis was to determine whether our
proposed BART determination would force FCPP to close entirely and thus create a significant
adverse impact to the Navajo Nation. However, as stated previously, this analysis is not
specifically required under the BART Guidelines.
The Navajo Nation requested that EPA provide an analysis of potential adverse impacts
to the Navajo Nation of APS's proposal to close Units 1 - 3 as an alternative emission control
strategy to BART. EPA notes that the RHR, in assessing an alternative measure in lieu of BART
(40 CFR 51.308(e)(2)) requires several elements in the alternative plan (e.g., demonstration that
the alternative will achieve greater reasonable progress than BART, and that reductions are
surplus to the baseline date of the SIP), but does not require an analysis of the cost of the
alternative plan.
35 "Signed Letter from APS to EPA 11-24-10", Document No. EPA-R09-OAR-2010-0683-0078.
36 See BART Guidelines, July 6, 2005, at 70 FR 39171.
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Although, an impact analysis of the alternative emission control strategy was not
required under the Regional Haze Rule, as requested by the Navajo Nation and as part of EPA 's
customary practice of engaging in extensive and meaningful consultation with tribes and tribal
authorities with regard to relevant Agency actions, EPA commissioned an analysis of the
potential impact to the Navajo Nation of APS's option to close Units 13. The report will be
provided to President Shelly by letter as a follow-up to our consultation with the Navajo Nation.
EPA also disagrees with the commenter that our cost analysis relies on "outdated"
sources and may underestimate compliance costs. As discussed above, EPA has determined that
the cost analysis conductedfor our October 2010 BART proposal is conservative because it
relies on the highest cost estimates submitted by APS, and reasonable because it incorporates
the site-specific costs estimated by B&Vfor APS while also considering the allowed line item
costs in the EPA Control Cost Manual. As noted above, our cost estimate is 18% lower than the
highest B&V cost estimate submitted by APS in 2009, and less than 0.6% lower than the most
recent cost B&V cost estimated submitted by APS in 2010. Therefore, reliance solely on APS's
most recent cost estimate in lieu of the EPA 's cost estimate presented in our proposed
rulemaking would not result in substantive changes to our BART determination.
3.2 Comments on Top-Down Analysis Versus Incremental Cost Effectiveness
Comment:
A number of commenters, including owners of FCPP (0168, 0174, 0176/0177, 0179,
0185), the Navajo Nation (0223), and a utility industry association (0187), asserted that EPA's
BART analysis was inconsistent with its own regulations in that it used a top-down analytic
approach and failed to conduct an incremental cost evaluation. These commenters typically
noted that the BART rules establish that both average cost effectiveness and incremental cost
effectiveness are to be used in the evaluation of BART (often citing 70 FR 39127, 39167-68).
Some of these commenters (0168, 0176/0177, 0179, 0185, 0187) added that a top-down
approach, which EPA uses for Best Available Control Technology (BACT) analyses, is
inappropriate for a BART analysis. One of the commenters (0176/0177) noted that BACT
requires the maximum degree of emissions reductions from new sources and major
modifications, taking into account various statutory factors established for the Prevention of
Significant Deterioration (PSD) program. The commenter indicated that for purposes of BACT, a
top-down analysis (while not required by the CAA) may have some justification because new
sources may more easily accommodate stringent control options. However, because BART
applies only to retrofits of existing sources (i.e., not to new facility construction), the commenter
argued that the most stringent controls may not be appropriate or cost effective for such existing
sources. Accordingly, the commenter asserted that a top-down methodology that is designed to
achieve maximum stringency and that fails to make a cost effectiveness comparison with less
stringent control options cannot be appropriate in the BART setting. The commenter added that
because a top-down cost assessment methodology is inconsistent with the BART rules and the
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nature and purposes of the BART program, EPA must abandon this approach and instead apply
the incremental cost effectiveness analysis described in the BART rules.
Another of the commenters (0187) stated that absent an incremental cost-effectiveness
analysis, EPA has no basis for concluding that SCR is a cost-effective control or that it is BART
for FCPP. A third commenter (0185) stated that given that EPA has failed to conduct an
incremental cost-effectiveness assessment, its proposed BART determination must be rejected.
The Navajo Nation (0223) indicated that in using the top-down analysis, EPA failed to
carry out the five-factor analysis for each of the technically feasible retrofit technologies as
required by the BART Guidelines (citing 40 CFR part 51, Appendix Y, section I.F.2.c),
including current combustion control technology which the BART Guidelines identify as
presumptive BART (citing section IV.D.5). The commenter stated that by only analyzing a
single technology which it chose in advance, EPA's analysis was clearly arbitrary and not in
compliance with its own regulations. The commenter concluded that EPA's compliance cost
analysis was fatally flawed.
Response:
EPA disagrees with these comments. In the preamble to the final BART Guidelines, EPA
discusses two options presented in the 2001 proposal and 2004 re-proposal of the guidelines for
evaluating ranked control technology options (See discussion at 70 FR 39130). Under the first
option, States would use a sequential process for conducting the analysis, beginning with a
complete evaluation of the most stringent control option. The process described is a top-down
approach analogous to the analysis we used in our proposed BART determination for FCPP. If
the analysis shows no outstanding issues regarding cost or energy and non-air quality
environmental impacts, the analysis is ended and the top level of technically-feasible controls is
identified as the "best system of continuous emission reduction The preamble describes an
alternative decision-making approach that begins by evaluating the least stringent control
technology (bottom-up approach) where the State would then consider the additional emissions
reductions, costs, and other effects of successively more stringent control options. In the final
guidelines, EPA decided that States should retain the discretion to evaluate control options in
whatever order they choose, so long as the State explains its analysis of the CAA factors.
Therefore, in conducting our BART determination for FCPP, EPA's top-down approach for
assessing the five factors was consistent with the discretion allowed under the BART Guidelines.
EPA additionally notes that the TSD for our proposed rulemaking included analyses of the costs,
non-air impacts, and visibility improvements associated with combustion controls at FCPP (the
level of control APS determined to be BART at FCPP), but that there is no requirement for a
five-factor analysis on all potentially available control options if the top down approach is used
and the top level of technically-feasible controls is selected (70 FR at 39130).
Comment:
One of the owners of FCPP (0176/0177) who alleged that the BART rules require an
analysis (see above) and provided an analysis comparing the costs of combustion controls to the
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costs of SCR. According to the commenter's analysis, the incremental cost effectiveness of
moving from combustion controls to SCR ranges from $6,553 to $8,605 per ton of NOx reduced
for the five units at FCPP. This commenter and another FCPP owner (0168) asserted that this
"extraordinarily high" incremental cost highlights the fact that combustion controls, not SCR,
satisfy the cost effectiveness test applied by EPA in adopting the presumptive BART limits in
the BART rules.
Response:
EPA agrees that the BART Guidelines recommend consideration of both average and
incremental cost effectiveness, however, EPA disagrees with the commenter that the incremental
cost effectiveness should be a comparison between combustion controls and SCR for this
particular facility. As discussed at length in the TSD for our proposed BART determination for
FCPP, EPA has determined that combustion controls (burner modifications and overfire air,
including ROFA) will not be effective at significantly reducing emissions at Four Corners due to
inherent design and physical limitations of the boilers. Therefore, in estimating incremental cost,
it is inappropriate to include combustion controls in the analysis for this particular facility. To
respond to this comment, EPA conducted an incremental cost effectiveness analysis and included
it in our docket for this final rulemaking.37 Based on our incremental cost analysis, EPA has
determined that the incremental cost of SCR compared to the next most stringent option is
reasonable and does not support the commenter's conclusion that SCR is not BARTfor FCPP.
The BART Guidelines recommend two types of cost effectiveness calculations - average
cost effectiveness and incremental cost effectiveness. Although there are no bright line
thresholds for determining the acceptability of average and incremental cost effectiveness
estimates, average cost effectiveness is the most commonly reported cost metric when comparing
controls for BART and BACT determinations. Therefore, we focused on average cost
effectiveness in our October 2010 BART analysis. However, we agree with commenters that the
BART Guidelines do recommend consideration of both average and incremental cost
effectiveness, therefore, we calculated incremental cost effectiveness using the methodology
described in the BART Guidelines (see 70 FR 39167 - 39168), such that incremental cost
effectiveness comparisons focus on the dominant alternatives that are identified by generating a
"least-cost envelope " graphical plot. The BART Guidelines describes the least-cost envelope to
represent the set of options that should be dominant in the choice of a specific option based on
total annualized cost and expected emission reductions.
Based on the least-cost envelopes for Units 1 - 5 of the control technologies APS
determined to be feasible at FCPP, the following NOx controls are the dominant options that
form the least cost envelope: combustion optimization systems (COS), Low NOx burner (LNB),
LNB+Overfire Air (OFA), LNB+OFA plus high energy reagent technology (LNB+OFA+HERT),
ROTAMIX+ROFA, and SCR on Units 1 and 2; COS, LNB+OFA, LNB+OFA+HERT, SCR on
Unit 3; and COS, LNB+OFA, SNCR+LNB+OFA, SCR on Units 4 and 5. The least cost envelope
methodology thus excludes from consideration the technologies that fall outside of this least cost
envelope. The incremental cost effectiveness for all options andfor all dominant options is
shown in the "Incremental cost.xlsx" spreadsheet included in the docket. Using the cost and
37 See "Incremental cost.xlsx", in the docket for this final rulemaking.
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emission reduction estimates provided by B&Vfor APS, the incremental cost of SCR when
considering all options and only the dominant options are comparable and ranges from
approximately $5,500/ton to $18,000/ton. Incremental cost of SCR is lower on Units 4 and 5,
and highest on Units 1, 2, and 3. This methodology already excludes the technologies APS
determined were technically infeasible (technical feasibility was determined before the cost
effectiveness determination) and also excludes technologies determined inferior from the least
cost envelope plot. However, as discussed at length in the TSD for our proposed BART
determination for FCPP, EPA has determined that combustion controls (burner modifications
and overfire air, including ROFA) will not be effective at Four Corners, particularly on Units 1
- 3, due to inherent design and physical limitations of the boilers. Therefore, in estimating
incremental cost, it is inappropriate to include an infeasible control technology in the analysis. If
we exclude the control technologies that EPA has determined to be ineffective at FCPP, SNCR
(without combustion controls) is the next most stringent alternative after SCR. The incremental
cost of moving from SNCR to SCR ranges from $3,500/ton to $5,800/ton using cost and emission
reduction estimates provided by APS. If we use the EPA 's revised cost estimate for SCR and
EPA's proposed N0X control efficiency of 80%, the incremental cost from SNCR to SCR ranges
from $2,500/ton to $3,300/ton.
Based on our incremental cost analysis, EPA has determined that the incremental cost of
SCR compared to selective non-catalytic reduction (SNCR), the next most stringent option
($2,500 per ton to $3,300 per ton), is reasonable and does not support the commenter 's
conclusion that SCR is not BARTfor FCPP.
3.3 Other Comments on Factor One
Comment:
One public interest advocacy group (0112) agreed with EPA's elimination of LNB
technology from BART consideration based on the TSD discussion which concluded that since
FCPP has had limited success in retrofitting Unit 2 with LNB technology, FCPP was unlikely to
achieve significant NOx reductions by retrofitting any of its boilers with LNB technology.
In contrast, one of the owners of FCPP (0176/0177) asserted that EPA's determination
that "combustion controls are not likely to be effective control technologies at FCPP" (citing
75 FR 64226) was based on superficial analysis and was mistaken. The commenter cited
Exhibit J to its comments on the ANPR,38 which contains a detailed analysis of the use of LNB
and OFA on FCPP's units. According to the commenter, this analysis confirms that the use of
advanced combustion controls on the five units at FCPP will reduce plant-wide NOx emissions
by 34 percent.
Response:
EPA disagrees with the commenter that Exhibit J of APS's comments on the ANPR
confirm that advanced combustion controls on all five units at FCPP will reduce plant-wide NOx
38 This document can be found in the docket for the ANPR, "Comments on ANPRM 09 0598 APS Comments and
Exhibits", Document No. EPA-R09-OAR-2009-0598-0195.
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emissions by 34%. Although APS makes that statement in its May 2, 2011 comment letter on the
2010 BART proposal, in its separate May 2, 2011 comment letter on the 2011 Supplemental
proposal, APS explains that further reductions in the N0X emission limit for Units 4 and 5 is not
appropriate for several reasons, including:
As discussed in EPA's Supplemental Proposal, there are site-specific operational
constraints at the Plant which will compromise its ability to comply with a lower
emissions level, such as the high ash-content of the coal and the "cell-burner "
configuration of the boiler. The Supplemental Proposal acknowledges that the cell-
burner configuration in Units 4 and 5 is not conducive to the application of advanced
combustion controls, typically employed prior to post-combustion processes such as SCR.
Therefore, all the desired emission reductions must be achieved with the SCR alone,
which limits the maximum achievable N0X reduction.
In this comment, APS contends that EPA 's conclusion, that advanced combustion controls will
not be effective at significantly reducing N0X emissions at FCPP, is accurate. Because of its
conflicting statements, it is unclear to EPA whether APS believes advanced combustion controls
will or will not be effective at FCPP. As outlined in the TSD for our 2010 BART proposal, EPA
concludes that advanced combustion controls will not be effective at significantly reducing N0X
emissions at FCPP, and therefore, our final BART determination requiring an 80% reduction in
N0X is based on the application of only SCR.
Comment:
One private citizen (0107) stated that EPA must consider the use of supplemental steam
from a concentrating solar power facility in determining BART for FCPP. The commenter
attached numerous articles that describe this technology, and indicated that these articles
establish that the technology is a viable option to reduce pollution from FCPP.
Response:
EPA disagrees with this comment that supplemental steam from a concentrating solar
power facility is an appropriate technology to consider in order to reduce pollution from FCPP.
The supplemental steam generatedfrom a solar facility is intended to offset some of the fuel
required to generate electricity. EPA does not have authority through BART to redefine a source,
nor is it feasible for a solar concentrating facility to offset enough fuel use to reduce NOx
emissions from coal combustion by 80% without the use of significant land area.
In 2010, EPA issued a PSD pre-construction permit to the City ofVictorville, in the
desert portion of southeastern California, to construct Victorville 2: a 563 megawatt (MW)
natural-gas fired combined cycle power plant with a 250 acre solar thermal array to provide 50
MW to the total electrical generation from the 268 MW steam turbine39. In order to offset NOx
39 See "PSD Permit Application April - 2007" or "Ambient Air Quality Impact Report", Document No. EPA-R09-
OAR-2008-0406-0001 or EPA-R09-OAR-2008-0406-0016. In 2011, EPA issued a PSD permit to a nearly identical
563 MW (net) natural gas fired combined cycle power plant with a 251 acre concentration solar facility to provide a
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emissions by 80% atFCPP using supplemental steam from a concentration solar facility, we
assume that the solar facility would need to provide 80% of the power at FCPP, or nearly 1,650
MW. Using the ratio of solar field acreage to electricity production (acres/MW) from Victorville
2 and a similar facility in Palmdale, California, we infer that approximately 8,250 acres (nearly
13 square miles) might be required to produce 1,650 MW ofpower. Even if EPA had authority to
require FCPP to reduce emissions by implementing a concentrating solar facility, the land area
and cost would likely prohibit substantial contributions from solar power to the total electricity
generation from FCPP at this time. However, because EPA's final BART determination is an
emissions limitation, rather than a technology requirement, and although EPA does not have
authority to require this technology, APS may consider this technology, or others, in developing
its plan to cost-effectively comply with EPA's final BART emission limit for N0X.
Comment:
One commenter at a public hearing submitted written material (0190) describing "fuel
lean gas reburn" technology, which the commenter stated should be considered in the BART
determination for FCPP. These materials indicate that this technology reduces NOx emissions by
30 to 45 percent. In his oral testimony, the commenter added that the ammonia used in SCR
systems is a hazardous material, which he would not like to see introduced into the area. He also
stated that the RHR allows a long period of time to meet the visibility improvement goals, and he
stated the use of fuel lean gas reburn technology in conjunction with combustion controls would
be appropriate at this time.
Response:
EPA disagrees with this comment. Fuel lean gas reburn technology was discussed in the
TSD for our proposed BART determination. Table 3 of the TSD included natural gas reburn as
an available NOx control option that B&V determined to be technically infeasible because the
technology has not been used in similar type or size facilities. However, even if this technology
was determined to be technically feasible, it ranked as a mid-range technology in terms of
control efficiency (65% control only when combined with LNB). Because EPA 's proposed BART
determination is a NOx emission limit rather than a specific technology requirement, in
complying with BART, APS may consider implementing a combination of other technologies in
lieu of SCR provided the alternative can meet the NOx limit specified in the final FIP. In the
absence offeasible control technologies that are capable of achieving 80% or greater reduction
in NOx emissions, EPA assessed the cost of controls assuming SCR would be used to comply with
the BART limit.
maximum of 50 MW to electric generation from the steam turbine to the City of Palmdale for the Palmdale Hybrid
Power Project in California. See "Initial PSD Palmdale Permit Application" or "Fact Sheet and Ambient Air Quality
Impact Report for the Proposed PHPP PSD Permit (SE-09-01)", Document No. EPA-R09-OAR-2011-0560-0002 or
Document No. EPA-R09-OAR-2011-0560-0004.
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4.0
Comments on Factor Two - Economic, Energy, and Non-Air
Quality Environmental Impacts
4.1 Comments on Economic Impacts
4.1.1 General Comments on Economic Impacts
Comment:
In virtually identical comments submitted prior to the supplemental proposal, one public
interest advocacy group (0094) and one environmental group (0146) offered comments on both
FCPP and NGS stating that EPA's analysis of historical and expected costs of electricity from
FCPP neglect to include public health costs related to air pollution and the negative impacts to
tourism resulting from loss of visibility. The commenters concluded that the cost-effectiveness
metric used to determine BART at both plants must account for health costs related to poor air
quality. The commenters requested that EPA consider economic costs on impacted communities
and Class I federal areas for not "cleaning up" both facilities.
Two private citizens who submitted written comments at a public hearing (0190)
similarly indicated that environmental and health costs related to FCPP should be considered
along with energy costs. One private citizen (0181) also claimed that pollution from FCPP has
impacted the region's economic health because of costs the Four Corners region has sustained.
Response:
EPA disagrees with the comment that the cost-effectiveness of BART must account for
public health costs associated with poor air quality. Neither Section 169A of the Clean Air Act,
nor the BART Guidelines, require that BART analyses include or quantify benefits to health or
tourism. As discussed previously, although not required by the BART Guidelines, EPA did
conduct an affordability analysis in our proposed BART determination to estimate whether the
installation and operation of SCR on Units 1 - 5 at FCPP would render the cost to produce
electricity at FCPP un-competitive compared to the cost to purchase electricity on the open
market. Although a quantitative analysis of the health and tourism benefits is beyond the scope of
what is required under BART EPA agrees with commenters that emission reductions achieved to
improve visibility will also improve air quality. Improved air quality, in turn, affects public
health and may enhance tourism in the area.
EPA notes that even if we had quantified the benefits to health and tourism, such an
analysis would not likely have altered the outcome of our BART determination.
Comment:
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The Navajo Nation (0223), one federal agency (0224), and two of the owners of FCPP
(0168, 0176/0177) stated that EPA must consider the collateral economic effects on the Navajo
Nation and the surrounding communities of its BART determination. One of these commenters
(0176/0177) noted that the BART rules permit broad economic effects to be considered in
determining the appropriate control technology and emissions limitations (citing 70 FR 39169
and the June 2007 Reasonable Progress Guidance, page 5-140). Another of the commenters
(0223) stated that the BART Guidelines (citing 40 CFR Part 51, Appendix Y, sections IV.D.4.h.5
and IV.E.3) and EPA's federal trust responsibility (see related comments in Section 10.0)
provide authority for considering the economic impacts to the Navajo Nation in the BART
determination for FCPP.
The Navajo Nation (0223) provided background on the substantial economic interest that
the Navajo Nation has in the continued operation of FCPP. The commenter noted that the Navajo
reservation has little economic development and that the Navajo people who live there are
among the poorest in the United States, with 42 percent of Navajo individuals living below the
federal poverty line. The commenter indicated that FCPP is located on Navajo land pursuant to a
lease agreement with the Navajo Nation, as is its coal supplier, the Navajo Mine; together these
entities provide income to the Navajo Nation that contributes substantially to the Nation's
economic viability and its sustainability as an independent sovereign:
• FCPP employs 586 people, 72 percent of whom are members of the Navajo Nation, with
an annual payroll of $41 million.
• The Navajo Mine employs 357 employees, 87 percent of whom are Navajo tribal
members, with salary and benefits that exceed $41 million.
• The Navajo Mine paid royalties and taxes to the Navajo Nation of approximately
$45.9 million in 2008.
• Together, those employed at FCPP and the Navajo Mine make up about 3 percent of the
total Navajo Nation employed workforce, which is very important on the Navajo Nation
where unemployment has hovered just below 50 percent for years.
• In 2008, the combined income derived from FCPP and NGS and the mines that supply
them totaled approximately $93.9 million, or about 55 percent of the Navajo Nation's
General Funds Budget.
The Navajo Nation (0223) added that this resource extraction-based economy is the result
of a conscious effort of the United States from the 1950s to develop the Nation's coal resources,
often for the benefit of other parties (such as the non-Navajo communities of Phoenix and
Tucson in southern Arizona who directly benefit from power allocated from NGS to pump water
for the Central Arizona Project). The commenter asserted that for the federal government,
through any agency, to now threaten the livelihood of the Nation by destroying the resource
economy it created clearly violates the federal trust responsibility to the Navajo Nation. The
commenter also stated that the Nation has already suffered the ripple effects of one EPA
rulemaking that, through the imposition of financially untenable emissions controls, resulted in
40 See "Guidance for Setting Reasonable Progress Goals Under the Regional Haze Program", June 1, 2007, in the
docket for this rulemaking.
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the closure of the Mohave Generating Station, and as a consequence, the closure of the Black
Mesa Mine. According to the commenter, if FCPP and the Navajo Mine were to close as the
result of the imposition of cost-prohibitive emission controls, the resulting revenue and job losses
would be cataclysmic for the Navajo Nation.
The Navajo Nation (0223) alleged that EPA gave virtually no consideration in its BART
analysis to the potential impacts on the Navajo Nation. According to the commenter, EPA
casually dismissed a real likelihood of disastrous economic impacts to the Navajo Nation by
claiming that there is no "definitive information" that FCPP would close if SCR is made BART
for FCPP and relying solely on its own economic analysis to conclude that FCPP "is expected to
remain competitive." The commenter asserted that as the Nation's trustee, EPA failed to properly
balance the gravity of the potential harm to the Nation should FCPP come to a different business
decision regarding the future competitiveness of FCPP with the imposition of SCR. The
commenter stated that where there is a great deal of uncertainty for FCPP because of other
issues, e.g. ongoing lease renewal processes and needed changes in ownership structure of FCPP,
EPA's failure to weigh the impact of imposing SCR in that context is particularly troubling.
The Navajo Nation (0223) stated that EPA should have analyzed in detail the potential
economic impacts to the Navajo Nation should EPA require the installation of costly control
technologies that the commenter asserted exceed the requirements of the RHR. The commenter
concluded that contrary to its trust responsibility, the RHR, and the BART Guidelines, EPA
failed to factor into its BART analysis the true potential economic impacts of imposing SCR on
FCPP, and failed to appropriately defer to the Navajo Nation's reasonable wish to phase in SCR
in a more conservative and cost-effective approach.
The Navajo Nation (0223) also pointed out that there are three coal-fired power plants
located on or near the Navajo Nation (FCPP, NGS, and San Juan Generating Station (SJGS)) that
are all subject to simultaneous BART rulemaking. The commenter indicated that all three power
plants and the coal mines that supply them contribute to the Navajo Nation's economy and
regional economic dynamics, and that there are additional emissions sources (major and minor)
contributing in varying percentages to emissions in the region. The commenter asserted that all
these sources should be considered in crafting the BART FIP for FCPP, where the tribal and
regional economic impacts must be balanced with the degree of visibility improvement that
would meet reasonable progress.
Another of the commenters (0176/0177) gave an overview of the Navajo Nation's
comments on the ANPR for FCPP, particularly the importance of FCPP and the associated coal
mine to the economy of the Navajo Nation and the significant impact on the Navajo economy if
FCPP were to close as the result of the imposition cost-prohibitive emission controls. The
commenter indicated that a BART determination requiring SCR at FCPP may make Units 1-3
uneconomical and force closure, and the same may be true for Units 4 and 5 depending on the
disposition of Southern California Edison's interest in those units.
The commenter (0176/0177) asserted that EPA must consider and respond to these
potential impacts of its BART determination; EPA cannot simply dismiss this issue because "it
has received no definitive information that FCPP intends to shut down or curtail operations"
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(citing 75 FR 64227). The commenter stated that the economic role that FCPP plays in the region
and with the Navajo Nation magnifies the importance of striking the right balance in a BART
determination - especially given that the BART determination is about visibility and not about
protecting public health.
The federal agency commenter (0224) noted that EPA's current affordability analysis
focuses primarily on increased costs to rate payers and the companies' profitability, and stated
that the analysis needs to incorporate the loss in revenue Jobs, and royalties resulting from the
closure of Units 1-3 under the supplemental proposal. The commenter added that all key
decision-making federal agencies must remain vigilant when making decisions that impact
Navajo tribal trust resources and the economic well-being of the Navajo Nation.
Two private citizens who submitted written comments at a public hearing (0190) also
expressed concern that additional regulation of FCPP could have negative economic impacts on
the Navajo community.
Response:
EPA agrees with commenters that the operation of FCPP and the Navajo Mine
contribute significantly to the economy of the Navajo Nation and the Four Corners Region.
However, we disagree with commenters that EPA casually dismissed the possibility of plant
closure. It is not EPA 's intention to cause FCPP to shut down (nor is it within our regulatory
authority under the RHR to require shutdown or to redesign of the source for BART). As
expressed in comments from the Navajo Nation to our Advanced Notice of Proposed
Rulemaking41, EPA understands that the Navajo Nation'sprimary concern regarding the BART
determination is the potential for FCPP closure. For this reason, EPA conducted an
affordability analysis not typically included in a BARTfive-factor analysis in order to assess
whether requiring SCR on all five units at FCPP would result in full closure of the power plant.
The assessment compared the cost ofpower from FCPP if SCR were required on all five
units, to the estimated cost of replacement power, assuming the owners of FCPP were to decide
to close the entire plant rather than make the SCR investment. The model was designed to
answer the question as to which future alternative results in lower power costs: a) power
produced at FCPP after installation of SCR, or b) replacing the power from FCPP with the
appropriate amount of wholesale power purchases. If the model results suggested that it would
be less costly for the owners to purchase replacement power on the open market than generate
power itself after installing and operating SCR on all five units, then EPA would have taken that
result, along with subsequent impacts to the Navajo Nation, into consideration in our proposed
rulemaking. However, as discussed in the TSD for our proposed BART determination, the model
results suggested that even if the owners of FCPP installed and operated SCR on all five units, it
could still produce power at a lower cost than the cost to purchase replacement wholesale power
on the open market.42 Thus, EPA concluded in our proposed BART determination that requiring
41 Comment letter from President Joe Shirley, Jr. dated March 1, 2010 in the docket for the ANPR: EPA-R09-OAR-
2009-0583-0209.
42 "FCPP Proposal - Technical Support Document 10-6-10", Document No. EPA-R09-OAR-2010-0683-0002,
"TSD Appendix B: Economic Analysis (EPA) of Proposed BART Determination on FCPP Final Report",
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SCR as BART on all five units would not likely result in plant closure. EPA recognizes that
market conditions for power on the wholesale market are highly variable and will likely differ
now, or at any time in the future, compared to conditions that existed at the time of our proposed
BART determination. However, no information was provided by the commenter to change our
conclusion in the analysis we conducted for the proposed rulemaking that suggests installation
of SCR on all five units would not likely result in plant closure.
EPA recognizes the importance of the power plants and the mines that fuel them as they
relate to the economic well-being of the Navajo Nation. EPA understands the importance of
quantifying potential impacts to the Nation of closures of one or more units at FCPP. At the
request of the Navajo Nation, as part of EPA 's customary practice of engaging in extensive and
meaningful consultation with tribes and tribal authorities with regard to relevant Agency
actions, EPA commissioned an analysis to estimate potential adverse impacts on the Navajo
Nation of the optional BART Alternative. The analysis will be provided to President Shelly by
letter as a follow-up to our consultation with the Navajo Nation.
With respect to the suggestion that an EPA rulemaking resulted in closure of the Mohave
Generating Station several years ago, EPA would like to clarify that Mohave 's closure was not
the result of an EPA rulemaking. Rather, the owners of Mohave Generating Station entered into
a Consent Decree with several environmental groups, including the Grand Canyon Trust, Sierra
Club, and the National Parks Conservation Association. That Consent Decree required
Mohave's owners to install pollution controls to reduce emissions of SO 2 and PMfrom the
facility. The Consent Decree required installation of the pollution controls by the end of2005.
The decision by the owners of Mohave appears to have been shaped by numerous complex
factors. EPA was not involved in the decision-making process or the regulatory proceedings
surrounding it. The Mohave Generating Station used coal that was mixed with water and
conveyed as slurry in a pipeline. The water to make the slurry was drawn from the N aquifer
from the Hopi Reservation. EPA understands that a contract to use the water from the N aquifer
expired in 2005 and was not renewed. The lack of a reliable source of water for the coal slurry
likely contributed to the decision by the owners of the Mohave Generating Station to discontinue
operations at the end of2005. Furthermore, it is EPA's understanding that in 2006, Salt River
Project (SRP), a co-owner of Mohave, sought to form a new ownership group to restart Mohave,
including to install the new air pollution controls required by the Consent Decree as well as
develop a new water supply system for the coal mine, however, SRP ended its efforts to restart
Mohave because it could not negotiate its intended purchase of Southern California Edison's
share of Mohave in time to restart by 2011.43 Therefore, although EPA understands that the
Navajo Nation and Hopi Tribe experienced adverse impacts from the closure of Mohave
Generating Station in 2005, the closure and the failed efforts to restart Mohave are not
attributable to, or the result of, EPA rulemakings.
Document No. EPA-R09-OAR-2010-0683-0005, "TSD ref [49] Economic Analysis of Proposed EPA Bart
Determination on FCPP 09-18-10 RATES.xlsx", Document No. EPA EPA-R09-OAR-2010-0683-0005-0040.
43
See February 6, 2007 Media Advisory from SRP: "SRP Ceases Effort to Restart Mohave Generating Station;
Concludes that Timeline Delays would Render the Facility Economically Unfeasible", and article in Power
Engineering Magazine: http://www.power-eng.com/articles/print/volume-l 1 l/issue-3/departments/startup/srp-
decision-seen-as-ending-mohave-re-start.html
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Comment:
The Navajo Nation (0223) asserted that EPA failed to consult with the Nation prior to
publishing the supplemental proposal and failed in its trust responsibility to consider the
potential adverse impacts of the option to close Units 1-3. While conceding that the
supplemental proposal is less likely to result in closure of the entire FCPP, the commenter noted
that Units 1-3 represent 27 percent of the capacity of the plant and closing these units will
affect the Navajo Nation's tax revenues and jobs, and will affect production at the Navajo Mine
as well. According to the commenter, in public hearings held in Farmington, NM, FCPP has
reported that as a result of closing Units 1 - 3, it expects 190 to 200 jobs to be lost in the next 3
to 4 years due to attrition at FCPP, an expected $5 million reduction in the possessory interest tax
paid annually to the Nation, and a 30 percent reduced demand for coal at Navajo Mine. The
commenter also stated that at the Navajo Mine, 150 to 200 jobs are expected to be lost over the
next 3 years as a result of the reduced demand from closure of Units 1 - 3 at FCPP, with a
resulting $10 million reduction in annual coal royalties to the Navajo Nation.
The commenter (0223) stated that as the Navajo Nation's trustee, and in determining a
"better than BART" alternative, EPA nonetheless retains its obligation to analyze potential
adverse impacts to the Navajo Nation. The commenter argued that EPA is violating its trust
responsibility in not adequately assessing these impacts for a plant operating on Navajo Nation
land and burning Navajo coal, especially where EPA must assume the Nation's duties to its tribal
members in making this determination in lieu of the Nation.
Response:
A timeline of correspondence and consultation with the Navajo Nation and other tribes
for EPA actions on FCPP and Navajo Generating Station is included in the docket for the final
rulemaking.44 EPA notes that the Regional Administrator of EPA Region 9 called President Joe
Shirley on February 9, 2011 to inform him of EPA 's Supplemental Proposal. However,
government-to-government consultation with the Navajo Nation on FCPP did not occur until
May 19, 2011, with additional consultation occurring on June 13, 2012, prior to issuing our
final rulemaking. The Navajo Nation raised concerns about the potential adverse impacts of the
BART Alternative and requested that EPA conduct an analysis to estimate these impacts.
Although the RHR does not require a cost analysis of a BART alternative, at the request
of the Navajo Nation and as part of EPA 's customary practice of engaging in extensive and
meaningful consultation with tribes and tribal authorities with regard to relevant Agency
actions, EPA commissioned an additional analysis to estimate potential adverse impacts on the
Navajo Nation of the BART Alternative with respect to coal and power plant-related revenues.
The report will be will be provided to President Shelly by letter as a follow-up to our
consultation with the Navajo Nation.
44 See document titled: "Timeline of all tribal consultations on B ART.docx" in the docket for this final rulemaking.
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Comment:
One environmental advocacy group (0182) commented that in rigorously addressing
visibility-related pollutants, the Navajo Nation, New Mexico, the intermountain west, and the
Colorado plateau stand to reap significant benefits and avoid serious consequences because such
emissions have far-reaching impacts on local economies. The commenter noted that tourism is
critical to the economy of the Navajo Nation, New Mexico, and the Four Corners region, and
that many national parks and landmarks are impacted by FCPP. The commenter pointed out that
visibility in such areas has been degraded, and that poor visibility affects park visitation and
length of stays.
One public interest advocacy group (0143) similarly noted that national parks and
monuments, wilderness areas, forests, and local culture bring tremendous economic benefit to
the Four Corners region, and that residents rely on tourism and the region's natural resources for
long-term economic growth and sustainability. The commenter added that oil and gas
development, over-grazing, and prolonged drought combined with coal-fired power plant
pollution have resulted in a continuing degradation of air quality and its impact on the soil and
vegetation. This commenter supported reducing pollution for FCPP through implementing the
supplemental proposal.
The environmental advocacy group (0182) also stated that installation of pollution
controls creates short-term construction employment and permanent operations and management
positions. Thus, the commenter asserted that installation of additional and upgraded pollution
controls will result in jobs and revenue for the Navajo Nation and its citizens.
Response:
EPA agrees that tourism is important to the economy of the Four Corners region,
however, the economic benefits of tourism and the benefits of short-term construction
employment associated with installation of air pollution controls are outside the scope of the
BART analysis. The BART Guidelines require consideration of the costs of compliance, and do
not similarly require an analysis of the economic benefits resulting from BART controls. The
model used by EPA was developed to address the future comparative cost ofpower from FCPP
with SCR against the wholesale power market to determine if FCPP would remain competitive if
SCR were required as BART.
Comment:
One owner of FCPP (0168) stated that EPA's proposal to require SCR at FCPP presents
significant challenges and risks and, with regard to their resource planning, handicaps their
ability to cost-effectively respond to changing conditions. The commenter pointed out that
implementation of the BART proposal would require the commenter to make a significant
capital investment in FCPP, which could only be recovered through long-term operation of the
plant. According to the commenter, this would have the effect of locking FCPP into the
commenter's generation portfolio for a considerable period or risk stranding those investments.
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The commenter indicated that this loss of flexibility would hamper the commenter's ability to
respond to future scenarios and likely preclude it from reacting to the following possible
developments:
• Changes in the economic viability of coal resources due to the increasing costs of
environmental regulations, including carbon limits.
• Changes in the acceptance of coal resources by state utility commissions.
• Low, sustained natural gas prices, which would favor natural gas resources over coal.
• Reduced demand for coal resources due to increases in renewable generation capacity
and/or reductions in customer load due to energy efficiency and demand response
programs.
• Advances in emission control technology.
The commenter (0168) asserted that this loss in flexibility and the risk it represents is
completely unnecessary given that the Regional Haze program is intended to make gradual
reductions in emissions over a decades-long period of time. The commenter stated that EPA
should therefore recognize combustion controls as BART for FCPP and evaluate further
reductions, such as installation of SCR, if it is shown to be justified in subsequent planning
periods. (See more on this comment in Section 10.0.)
Response:
EPA appreciates the perspectives shared in this comment, but we disagree that our five-
factor BART analysis should consider the potential loss of an owner's flexibility to respond to
possible future economic or regulatory scenarios. EPA cannot give substantial consideration in
our BART analysis to external factors that are of uncertain magnitude and that may or may not
occur. EPA further notes that the RHR allows for the development of BART alternatives that
achieve greater reasonable progress than BART and EPA appreciates the fact that the owners of
FCPP put forth an alternative that gives them more flexibility and results in greater emission
reductions at FCPP.
EPA acknowledges that other potential environmental regulations or public policies may
emerge which could also have an impact on the competitiveness of FCPP and that, should these
new regulations or policies emerge, will require the plant owners to assess the economic impact
to plant's competitiveness. However, the impacts studied in this analysis were limited in scope to
determining likely effects from the proposed BART determination exclusively.
4.1.2 Comments on EPA's Economic Analysis
Comment:
One public interest advocacy group (0112) concurred with the EPA's analysis that the
potential increase to APS rate payers as a result of SCR is expected to be less than 5 percent, as
described in the TSD. The commenter also stated support for EPA's analyses related to the
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increase in electricity generation costs of SCR compared to estimated costs to purchase
electricity in the wholesale market. The commenter asserted that EPA estimates are reasonable
and that the average increase in the cost of generation at FCPP as a result of SCR
implementation would be 22 percent, or $0.0074/kWh, as stated in the TSD.
One of the owners of FCPP (0176/0177) stated that installation of BART controls would
increase its average residential customer monthly bills by $5.10 (3.8 percent) and larger
industrial customer monthly bills by $17,400 (6.4 percent). (We believe that the commenter was
referring to SCR, although the commenter asserted that BART should be combustion controls.)
The commenter also indicated that installing SCR and baghouses on Units 1-3 would increase
the cost of electricity production on a $/MWh basis by more than 50 percent which, in
conjunction with other market and regulatory uncertainties, may make the units uneconomic. The
commenter further stated that retrofitting SCR on Units 4 and 5 would raise the cost of
generation at those units by more than 25 percent, and there is a reasonable possibility that such a
cost increase would threaten the economic viability of those units.
Another one of the owners of FCPP Units 4 and 5 (0168), who also has ownership
interest in NGS and SJGS, stated that if SCR were determined to be BART for all these power
plants, the commenter would be facing approximately $322 million in capital expenses over the
next 5 years. The commenter indicated that such expenditures would increase the commenter's
rates by 4 to 6 percent, which would be significant in its market area of Tucson because its
economy is fragile and has endured an 8 percent rate increase (not adjusted for inflation) since
1992. The commenter stated that the Tucson area is struggling through difficult economic
circumstances, and significantly higher electricity rates will place an enormous economic
hardship on its customers and make any recovery more difficult for the community.
Response:
EPA agrees with the first commenter (0112) that based upon our analysis the potential
increase to APS rate payers as a result of SCR is expected to be less than 5 percent.
EPA cannot compare the estimated residential and industrial rate increase claimed by
the second and third commenters with our analysis because the commenters did not provide
information for us to evaluate their conclusions.
However, EPA notes that the installation of baghouses on Units 1-3 is no longer relevant
because EPA has determined that it is not necessary or appropriate at this time to set new PM
limits for Units 13. This is because EPA is finalizing this BART determination to allow APS to
comply with either BART or the BART alternative, which involves the optional closure of Units 1
- 3, and as a backstop, if APS does not close Units 1-3, the MATS rule, which sets a filterable
PM emission limit of 0.03 Ib/MMBtu, is now final and would apply to those units.
While the commenter's suggested increase in the cost ofpower from Units 4 and 5 as a
result of SCR (25% increase) is reasonably consistent with the results of the EPA analysis (22%)
with respect to the power cost impact of SCR on all five FCPP units, it must be noted that the
original EPA analysis did not evaluate SCR on Units 4 and 5 exclusively. Without evaluating the
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modeling conducted by the commenter, it is not possible to compare the commenter 's modeling
results with the model from the EPA 's proposed BART determination.
In order to provide a more complete response to the commenter's point regarding costs
specific to Units 4 and 5, however, EPA re-ran the same model used in our proposed BART
determination to assess the impact of SCR for only Units 4 and 5.45 The model assumes that
Units 1-3 are closed, and as such, it produces no power and does not impact total plant
economics. This iteration of the model reported a 25-year net present value incremental cost of
14% for only Units 4 and 5. The difference in the EPA model between the 22% cost increase for
all five units versus the 14% cost increase for only Units 4 and 5 is due to the fact that while the
estimated capital costs and incremental operating costs for Units 1-3 account for 36 percent and
39 percent of the total modeled incremental capital and operating cost respectively for the entire
plant, those three units account for only 27 percent of installed plant capacity. Thus, the "per
unit" cost associated with Units 1-3 is significantly higher than Units 4 and 5.
Comment:
One of the owners of FCPP (0174) noted that based on the analysis performed in support
of EPA's BART proposal for FCPP, EPA concluded that even if SCR is determined to be BART,
the cost of generating power at FCPP would be less than the cost of purchasing power on the
wholesale market, and that therefore a requirement to install SCR would not lead to closure of
the plant. The commenter expressed the following concerns with the analysis:
• The analysis focuses on APS and Southern California Edison, and not on the other
owners of FCPP. The use of "return on rate" based methodology would not apply to
organizations of the commenter's type (public power) because it is not an investor-owned
utility.
• Each of the FCPP owners has unique costs related to the plant and their own generation,
transmission, and distribution costs. Therefore there are a multitude of company-specific
factors that would impact a given owner's decision to invest additional capital in the plant
for emission controls, none of which were specifically factored into the EPA analysis.
• The EPA analysis did not attempt to determine the impact of different assumptions, such
as an uncertainty with the future price of coal, on the conclusions of the economic
analysis. The "small difference" that EPA estimates between FCPP with SCR installed
and cost of purchasing power to replace FCPP generation suggests that a small change in
an underlying assumption (return on rate, coal price, carbon pricing, etc.) could result in
economic results that show SCR to be a higher cost option than purchasing power.
• The EPA's analysis did not examine different "payback periods," but instead relied on a
payback period of 25 years, which may be inappropriate because the useful life of the
plant is far from certain. The remaining useful life of FCPP is dependent on many other
factors - both political and regulatory in nature (citing comments by Commenter
0176/0177; see Section 6). Shorter payback periods should have been analyzed to
determine the effect of this assumption on the conclusions of the analysis because a
45 See "Analysis of UNITS 4 & 5 SCR ONLY.xlsx" in the docket for this final rulemaking.
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reduced payback period could result in FCPP power (with SCR costs included) exceeding
wholesale market costs.
• The EPA should recognize that there is a real risk that one or more owners may decide
not to invest in SCRs, which would force the shutdown of FCPP unless another owner
could be found in a timely manner. The shutdown of FCPP would have significant
adverse economic consequences on the Navajo Nation.
• If EPA were to consider these economic challenges and uncertainties in conjunction with
the other BART statutory factors, EPA would conclude that combustion control should
be determined to be BART for FCPP because it provides a cost-effective means to
achieve visibility improvement in the first planning period. EPA can evaluate whether
additional NOx reductions are warranted in subsequent planning periods, which is
consistent with the RHR and would provide the FCPP owners with time to address the
uncertainties facing the plant before making significant capital investment for SCR.
Response:
EPA provided an analysis for our BART determination to assess whether the cost to
produce electricity at FCPP would remain competitive compared to the market costs to purchase
power if SCR were required on Units 1 - 5 at FCPP.
The commenter is correct that EPA calculated rate impacts for only two of the four
investor-owned utilities that own FCPP and excluded others, including an owner that operates
as a publicly-owned utility. The analysis estimating the increase in electricity generation costs is
applicable to all owners of FCPP, and the rate impact analysis provided in the model was not
intended to capture the rate impacts of all owners. APS and Southern California Edison (SCE)
were selected because their combined ownership shares account for nearly 75% of the plant's
output. In addition to our expectation that the utilities with the largest ownership share in FCPP
would generally experience greater ratepayer impacts from capital expenditure projects like
SCR installation, we also assumed that ratepayers of investor-owned utilities would likely
experience larger economic impacts than public power customers due to the fundamental
difference between their respective approaches to setting rates. Specifically, rates for public
power utilities, in contrast to investor-owned utilities, do not include recovery for a margin
above cost allowed as part of a regulated rate of return. Thus, all other variables being equal,
one would expect the same capital investment to result in a larger rate impact for customers of
investor-owned utilities than for customers of public power entities. Therefore, EPA continues to
believe that our analysis of ratepayer impacts for only APS and SCR are appropriately
conservative to demonstrate worst-case impacts to ratepayers.
EPA agrees with the commenter that there are many company-specific factors and a wide
range of economic assumptions that would impact a given owner's decision to invest in SCR.
Although many of those factors were outside the focus of the modeling because they were either
unrelated to BART or were related to regulatory uncertainties in the future, Energy Strategies
included a qualitative discussion in Appendix B to the TSD regarding decision variables that
EPA assumed each owner must consider before making capital expenditures. Additionally, EPA
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notes that the use of low, medium and high future projected prices for the Palo Verde Index
represents a sensitivity analysis for the market comparison.
With respect to the "payback period" referenced by the commenter, the analysis for the
proposed BART determination did not identify "paybackperiods. " Rather, the commenter
appears to be referring to the 25-year period utilizedfor the discounted cash flow calculations
within the model. EPA does not disagree with the commenter's stated concern that shorter plant
life, and thus shorter discounting periods, would yield different economic results. However, EPA
disagrees with commenters that a shorter useful life should be considered in the analysis unless
there is an enforceable obligation on APS to cease operations on a given date.
Comment:
One private citizen commenter (0180) provided comments on EPA's economic analysis,
which are summarized below:
• The report of the economic analysis appears to be inconsistent in that in numerous places
(e.g., page 5) it shows the business as usual (BAU) and LNB cases to be less expensive
than all other cases, while on page 20 it states that the 25-year non-discounted costs for
the SCR case were lower than both the BAU and LNB/OFA cases.
• The market cases do not incorporate the impact of removing FCPP generation from the
marketplace. Specifically, the shutdown of FCPP would, first, result in a lack of
generation capacity in the market and affect the market price and, second, as the lack of
base loaded generation was made up by natural gas fired combined cycle plants that are
currently run to meet peak load, the increased need for natural gas may strain pipeline
capacity and cause the price of natural gas to rise.
• The report of the analysis states that, "although new capital expense has not been
considered in the BAU case, if it were and especially if the addition were to occur early
in the time horizon envisioned in the economic model, the cost of the BAU case could
increase materially with respect to other cases." This statement is invalid, as new capital
deployment would be required in any case regardless of whether SCR or LNB are
installed.
• The report says on page 8, "It is reasonable to assume that the parties that rely on the
continued operations of the mines and plants could be reasonably expected to make an
economic decision and negotiate new leases that allow the plant to operate
economically." The commenter states that EPA seems to be unaware of the Mohave
Generating Station, which serves as a counter-example to the statement in the report.
Response:
In the first bullet above, the commenter correctly identifies a discrepancy with the
summary of the analysis. The impact report, included as Appendix B to the TSD46 for the
46 See Document titled "TSD Appendix B: Economic Analysis (EPA) of Proposed BART Determination on
FCPP Final Report. EPA-R09-OAR-2010-0683-0005.
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proposed rulemaking, on page 20 incorrectly states that the incremental cost in the SCR case is
lower than the LNB case, as well as all market cases. On page 20, under "Discussion of
Modeling Results, " the final bullet should read, "As modeled, the SCR Case over 25-years
returns a lower incremental, non-discounted cost per megawatt-hour than all market cases".
This incorrect statement in the summary of the impact report regarding incremental cost
comparison between SCR and LNB was a summary statement written by Energy Strategies but
was not directly relied upon by EPA in our TSD.
The commenter correctly points out that the analysis discussed in the report does not
include the potential impacts, and associated Market Case costs, that could result in reaction to
a shutdown of all units FCPP. The commenter suggests that a more complete approach to
modeling the cost of the Market Case would include such variables as the cost of new base
loaded gas-fired generation (in the marketplace or perhaps owned by the current FCPP owners)
and the potential for such new gas generation to influence commodity natural gas pricing in the
region. The result of including these additional costs in the Market Cases would be to increase
the estimated cost to purchase power on the wholesale market. Thus, the Market Cases presented
in the analysis that accompanied EPA's TSD were conservatively low, and inclusion of the
market-related impacts, as suggested by the commenter, would result in higher market values,
thereby providing a larger "competitive cushion "for the installation of SCR at FCPP.
As noted by the commenter in the third bullet above, the report incorrectly states,
"although new capital expense has not been considered in the BAU case, if it were and
especially if the addition were to occur early in the time horizon envisioned in the model, the cost
of the BAU case could increase materially with respect to other cases. " The statement should
read, " ...the cost of the BAU case could increase materially with respect to the Market Cases. "
As the BAU case may or may not increase in cost due to future business as usual-related capital
investment, the commenter is correct in suggesting that all retrofit cases (LNB and SCR) would
have the same relative impact due to BAU investments. The potential for BAU investments to
alter the comparative economics in the model are thus in relation to the Market Cases. However,
commenters have not provided information to suggest that new capital expenses should be
modeled in the BA U case, therefore, the commenter's correction is well taken, but does not affect
the validity of the modeling conducted for the TSD.
Contrary to the commenter's statement in the fourth bullet above, EPA is aware of the
regulatory and investment decision history surrounding the closure of the Mohave Generating
Station. (For a detailed discussion related to the shutdown of Mohave Generating Station,
please see our response above in Section 4.1.1).
Comment:
Three private citizens (0119, 0128, 0201) disagreed with industry that costs are too high.
One of the commenters stated that the reform measures are both reasonable and economically
feasible. Another private citizen (0140) stated that APS should be responsible for the clean-up.
Response:
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We agree with the commenters that SCR is a reasonable, cost effective control technology
for reducing emissions ofNOxfrom FCPP.
Comment:
One private citizen (0163/0164/0216) commented that the Navajo Nation previously
stated that both the power plant and the Navajo Mine would close if SCR is required. The
commenter took issue, noting that EPA indicated that FCPP electricity cost will still be market
competitive with SCR. The commenter stated that the economic analysis (and other analyses)
incorrectly used sub-bituminous coal heating values, rather than bituminous coal values,
resulting in a "flawed and incorrect way to improve the health and visibility to the Four Corners
area and Class I areas." The commenter also contended that the EPA's analysis stated that FCPP
uses bituminous coal, although the APS BART analysis was based on sub-bituminous coal.
Response:
EPA disagrees with this comment. With respect to the modeling of incremental costs
associated with those cases where FCPP operations continue (i.e. BAU, LNB/OFA, and SCR),
the type of coal burned and associated heat content were not germane to the analysis. The
underlying costs of operation, including fuel quantity and heat content, as they flow through the
summary economic statistics, are taken as-is from APS filings to the Federal Energy Regulatory
Commission and were not modified with respect to the type of coal consumed.
This comment regarding coal classification is addressedfurther in Section 10.
4.2 Comments on Energy and Non-Air Quality Environmental Impacts
Comment:
One private citizen (0180) stated that no consideration was given to the effect of
removing FCPP generation from the grid. According to the commenter, the events of February 2,
2011 show there are times when gas-fired generation cannot replace coal-fired generation
because there is not enough gas transportation capacity.
Response:
EPA disagrees with the commenter that we should consider the effect of removing FCPP
generation from the grid. As stated elsewhere in this document, it is not EPA 's intention, nor is it
within our regulatory authority, to require closure or require a redefinition of the source, in
order to comply with the BART requirement of the RHR EPA notes that in our proposed BART
determination EPA included an analysis to determine whether the installation and operation of
SCR would increase the cost ofpower from FCPP such that it would no longer be competitive to
the forecasted price ofpower in the western wholesale market. Thus, based on this analysis, EPA
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determined that the installation and operation of SCR on Units 1 - 5 at FCPP should not force
FCPP to close, thus the comment that EPA consider the effect of removing FCPP generation
from the grid is not relevant. Furthermore, the owners of FCPP did not provide evidence that the
installation of SCR would cause FCPP to close.
EPA also notes that APS proposed to purchase the shares of Units 4 and 5 currently
owned by Southern California Edison in order close Units 13 (of which APS is sole owner)
and install SCR on Units 4 and 5 as an alternative to BART. APS is currently seeking approval
from the Arizona Corporation Commission, the California Public Utilities Commission, and the
Federal Energy Regulatory Commission to implement its proposal47. Decisions on investing in
pollution controls or shutting down units are made by the owners in conjunction with their
oversight boards or public utility commissions.
Comment:
Thirty-seven private citizens (0085, 0086, 0088, 0089, 0091, 0122, 0124, 0125, 0127,
0128, 0135, 0136, 0137, 0140, 0147, 0148, 0149, 0151, 0153, 0154, 0155, 0156, 0158, 0159,
0160, 0161, 0162, 0166, 0170, 0171, 0181, 0188, 0197, 0199, 0208, 0211, 0213) and two private
citizens who submitted written comments at a public hearing (0190) stated that FCPP causes
significant threats to public health due to its effects on air quality. Another private citizen (0186)
implied the same concern, and is unwilling to trade a healthy environment for jobs or economic
growth. In contrast, one private citizen who submitted a written comment at a public hearing
(0190) questioned whether the haze contributes to health issues in the region.
A number of environmental and public interest advocacy groups (0143, 0182, 0183,
0190, 0194) provided comments on health and ecosystem impacts of the pollutants emitted by
FCPP. These comments are summarized below.
One group of environmental advocacy groups (0182) stated that visibility-causing
pollutants have far-reaching impacts on local economies, human health, and the well-being of
waterways, soils, plants, and wildlife - in other words, an entire population and ecosystems. The
commenter asserted that decreasing these pollutants will benefit all of these important areas of
concern; failing to do so will cause or continue adverse impacts. The commenter's thoughts on
the economic impacts of these pollutants are summarized in Section 4.1.1 above.
Regarding health impacts, the commenter (0182) noted that the same pollutants that
contribute to visibility impairment also harm public health - the fine particulates that cause
regional haze can cause decreased lung function, aggravate asthma, and premature death in
people with heart or lung disease. The commenter added that NOx and volatile organic
compounds (VOCs) can also be precursors to ground-level ozone, or smog, which is associated
with respiratory diseases, asthma attacks, and decreased lung function. According to the
commenter, ozone concentrations in parks in the Four Corners region approach the current health
standards, and likely violate anticipated lower standards. The commenter stated that ozone levels
47 On March 22, 2012, the California Public Utilities Commission approved the sale of SCE's share of FCPP to
APS. On April 18, 2012, the Arizona Corporation Commission approved APS's purchase of SCE's share of FCPP.
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in many parts of New Mexico, Colorado, and Utah are already in the range of ozone levels
deemed to be harmful to human health.
The commenter (0182) asserted that according to EPA figures, the total annual cost of
implementing the RHR will range from $1.4 - 1.5 billion, but in 2015 enforcement of the RHR
will provide health benefits valued at $8.4 - $9.8 billion annually - preventing 1,600 premature
deaths, 2,200 non-fatal heart attacks, 960 hospital admissions, and over 1 million lost school and
work days every year. The commenter noted that although the RHR was designed to provide
redress for visibility impairment, the BART Guidelines expressly provide for the consideration
of non-air quality environmental impacts, which includes the environmental impact on human
health.
The same commenter (0182) also contended that consideration of non-air quality impacts
extends to impacts on wildlife and habitat as well as natural and cultural heritage. According to
the commenter, the same haze-causing emissions also harm terrestrial and aquatic plants and
animals, soil health, and water bodies by contributing to acid rain, ozone formation, and nitrogen
deposition. The commenter cited EPA sources that allegedly indicate that nitrogen deposition in
the Rocky Mountain National Park is at twice the critical load that the ecosystem can tolerate;
that acid rain acidifies water bodies, contributes to tree damage at high altitudes, and accelerates
decay of irreplaceable buildings, statues, and sculptures that are part of our nation's cultural
heritage; and that ground-level ozone interferes with the ability of sensitive plants to produce and
store food, damages the leaves of trees and other plants, and reduces forest growth and crop
yields.
With these health and environmental considerations in mind, in addition to visibility and
economic considerations discussed in other sections of this document, the commenter (0182)
urged the EPA to finalize more stringent BART determinations for FCPP. The commenter's
suggestions for BART also are discussed in other sections of this document.
An environmental advocacy group (0183) made similar comments regarding health and
ecosystem impacts. The commenter noted that FCPP is a very large emitter of NOx, which
contributes to ozone formation. According to the commenter, the area around FCPP is subject to
atmospheric thermal inversions in the winter months, and some counties have experiencing
ozone concentrations in excess of the EPA's proposed range for the 8-hour ozone NAAQS. The
commenter cited the incidence of asthma and other respiratory diseases and noted that such
sensitive populations are particularly susceptible to the effects of ozone. In addition, the
commenter pointed out that ozone causes injury and damage to plants. The commenter added
that NOx emissions contribute to nitrate deposition which can disrupt natural systems. Based on
these points, the commenter argued that EPA must consider reducing the NOx limit in both the
proposed BART determination and the supplemental proposal.
This commenter (0183) stated that FCPP's PM emission rate is one of the top 10 point
sources of PM in the American West. The commenter contended that EPA has stated that
airborne PM is linked to serious health effects, even at concentrations currently allowed by the
NAAQS.48 The commenter also stated that black carbon (a type of PM) is the most powerful
48 citing http://www.epa.gov/nheerl/research/pm/
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climate forcing agent known, and that it has recently been determined to be the second or third
largest climate forcing agent. The commenter noted approvingly that the supplemental proposal
would provide additional PM reductions through the retirement of Units 1-3.
The commenter (0183) noted that FCPP is a significant source of mercury emissions and
provided information on the health and ecosystem effects of mercury, as well as on the
deposition of mercury and the levels of mercury found in the Four Corners area. In addition, the
commenter stated that FCPP emits more than 16 million tons per year (tpy) of C02, and that such
emissions contribute significantly to climate change which is likely to result in increasing
temperatures and increase drought in the Southwest. The commenter noted with approval that the
supplemental proposal would reduce emissions of both mercury and CO2.
One public interest advocacy group (0143) also discussed the health impacts associated
with emissions from FCPP. The commenter indicated that the emission reductions associated
with the supplemental proposal would work toward improving health and environmental justice
for people in the Four Corners area, including a large Native American population. The
commenter stated that health care costs resulting from coal-fired power plant pollution are
significant for the local economy, quoting figures from a study by Abt Associates estimating the
health impacts and associated costs in the area. The commenter also indicated that prevailing
winds carry pollutants from FCPP to La Plata County, CO, and that early findings from a new
mercury-monitoring project indicate that a significant amount of mercury arrives under dry
condition via wind at two monitors in southwest Colorado. Although the sources of the mercury
have not been verified, the commenter noted that coal-fired power plants are known to be a
major contributor of mercury to the atmosphere and that FCPP is reported to release more than
1,400 pounds of mercury per year. The commenter stated that known pollutants from coal-fired
power plants contribute negatively to health, vegetation, and soil impacts. The commenter also
pointed out that NOx emissions (of which FCPP is a large source) along with the Four Corners'
abundant sunshine create ground-level ozone and that if EPA lowers the ozone NAAQS, La
Plata County could be in nonattainment. While praising EPA's supplemental proposal as a good
first step, the commenter urged EPA to expand the region's reliance on lower carbon and water
efficient energy sources, adding that federal programs are available to assist tribes to evaluate
and install renewable sources of energy.
Another environmental advocacy group (0194) also quoted figures from the Abt
Associates study on the health impacts of emissions from power plants in the region. The
commenter supported the proposed measures to reduce NOx emissions, but noted that the
proposal did not address GHGs. The commenter encouraged EPA to take timely action to help
transition energy production away from fossil fuels to clean energy sources, adding that New
Mexico has abundant solar, wind, and geothermal energy resources.
One environmental advocacy group that spoke at a public hearing also submitted written
material (0190) asking EPA and APS to consider what they would do if FCPP was located in
their communities. The commenter supported a transition to renewable energy that will keep jobs
in the area and clean up the air in the Four Corners region. The commenter made the following
points:
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• A formal Health Impact Assessment should be conducted by independent experts before
EPA's final decision to answer such questions as whether shutting down Units 1 - 3 is
sufficient to protect local health, and what health impacts would result from delaying
pollution controls on Units 4 and 5 until 2018.
• The acceptable limit of pollution from FCPP is no more than would be allowed in the
wealthiest, most privileged communities in the United States; that is, the decision should
be made considering health equity.
• The spiritual aspect of the air, the earth, and water of Mother Earth must be taken into
consideration because to the Navajo people, clean air, water, and land are not
commodities to be bargained with, but are sacred elements of life to be protected at all
costs.
Response:
EPA agrees that there are potential benefits to human health and the environment from
reducing the emissions ofNOx. Quantifying health benefits is not within the scope of the BART
five factor analysis required under the Clean Air Act (§169A(g)), which specifies that in
determining BART, the State (or Administrator) "shall take into consideration the costs of
compliance, the energy and nonair quality environmental impacts of compliance, any existing
pollution control technology in use at the source, the remaining useful life of the source, and the
degree of improvement in visibility which may reasonably be anticipated to result from the use of
such technology The BART Guidelines provides additional information on how to analyze
"non-air quality environmental impacts, andfocuses on adverse environmental impacts
associated with control technologies, i.e., generation of solid or hazardous wastes and
discharges ofpolluted water, that have the potential to affect the selection or elimination of a
control alternative (see 70 FR at 39169). Thus, although the BART Guidelines do state that
relative environmental impacts (both positive and negative) of alternatives can be compared with
each other, they state that "if you propose to adopt the most stringent alternative, then it is not
necessary to perform this analysis of environmental impacts for the entire list of technologies
EPA agrees with commenters that controlling pollutant emissions may have co-benefits for
reducing ozone production and acid deposition, EPA does not interpret the BART Guidelines to
require quantification of human health or environmental co-benefits in determining BART,
particularly if the most stringent BART option is finalized. Similarly, EPA does not interpret the
BART guidelines to require human health or environmental assessments of alternative
compliance strategies as long as we have determined that the alternative strategy achieves better
progress towards the national visibility goal.
Comment:
The Navajo Nation (0223) recognized that human exposure to environmental hazards is
an important factor in assessing impacts of FCPP (and NGS and SJGS) and for framing a rule to
meet the regional haze requirements of the CAA, and anticipated that within each
implementation phase of the RHR there will be integration of health assessments and studies
which are interrelated to the goal of promoting a strong economy and healthy environment and
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are vital to the sovereignty of the Navajo Nation. The commenter encouraged EPA to pursue
health studies in collaboration with the Navajo Nation to study local risks associated with
exposure to criteria pollutants, indoor air pollutants, and other contributing air pollutants, from
which improved public health and effective rulemakings under the CAA may be achieved.
In addition, the commenter (0223) noted that EPA has stated that BART determinations
will improve public health in addition to improving visibility in the region, and the commenter
anticipated that EPA will take the same stance in the forthcoming NGS proposed rule. On that
issue the commenter provided the following comments:
• Very little public health data is available in the Four Comers region and on the Navajo
and Hopi reservations to establish a meaningful public health baseline.
• A meaningful public health baseline is critical to measuring the impacts to public health
for any BART option, or any other pending or future EPA rule making.
• The available research literature (Morris 1990, Robin 1995, Bunnel 2010) all conclude
that poor indoor air quality is a significant risk factor impacting the public health of
Navajos, especially those Navajos who heat their homes with non-optimal heating
devices.
• The EPA should generate and collect more public health research/data that characterizes
the actual public health impacts attributed to the emissions from the FCPP and NGS; and
actual public health impacts attributed to other emission sources.
Response:
Assessing human exposure and quantifying health benefits are outside the scope of the
requirements of the Regional Haze Rule. EPA sets National Ambient Air Quality Standards
(NAAQS) to establish levels of air quality that are protective ofpublic health, including the
health of sensitive populations, for a number ofpollutants including particulate matter. These
"sensitive"populations include asthmatics, children, and the elderly. At this time the Navajo
Nation is not identified as out of attainment with any of the NAAQS. However, EPA recognizes
that there are significant concerns about risk and exposure to air pollutants on the Navajo
Nation and EPA will continue discussions with the Navajo Nation and will involve other federal
agencies, as appropriate, to help address these concerns.
Comment:
The Navajo Nation (0223) stated that EPA has failed to consider the non-air impacts
associated with transportation and storage of ammonia for the proposed SCR technology. The
commenter alleged that EPA took a "safe approach" by hypothesizing the use of urea as the SCR
reagent as proposed by APS, and considered only the impacts to air quality from increased truck
traffic in the area from transportation of urea (not the risks associated with accidental releases
and spills). The commenter also noted that EPA did not assess the potential risks associated with
the transportation, storage, handling, and accidental release of anhydrous ammonia or aqueous
ammonia, which are typical reagents used in SCR. The commenter asserted that because
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anhydrous ammonia and aqueous ammonia above 20 percent are considered acutely hazardous
and accidental releases are reportable to local, state, and federal agencies, EPA should conduct
an extensive study of the risks associated with the use of these potential SCR reagents based on
the size of the plant and its location both by proximity to Navajo communities and residents and
to the nearest feasible rail line. The commenter indicated that transport and storage of anhydrous
ammonia would require development of a Risk Management Plan and Process Safety
Management plan by both the plant and the transfer facility at the rail line. The commenter added
that trucking of ammonia would be across Navajo land, potentially putting Navajo communities
at risk, and would generate air emissions of NOx, CO, VOC, and PMi0. The commenter
concluded that these risks and associated costs should have been analyzed in EPA's BART
analysis as part of factor two, considering EPA's trust responsibility to the Navajo People.
Response:
EPA disagrees with the comment that we chose the "safe approach " by analyzing for the
use of urea instead of anhydrous ammonia. APS has consistently indicated that it would use urea
if SCR were required as BART, providing estimated costs for urea as the reagent andfor urea
storage and handling equipment. Our approach was appropriate in light of the plans submitted
by the facility. Accordingly, the study did not evaluate any risks associated with spills or releases
of urea because urea is not classified as a hazardous or toxic substance under any federal
environmental program. Such spills or releases are not reportable incidents under emergency
management requirements.
EPA further notes that the results of a study to evaluate the potential risks associated
with increased emissions to transport urea to FCPP was included in the TSD for the proposed
rulemaking as Appendix A and can be found in the docket for the rulemaking, Document No.
EPA-R09-OAR-2010-0683-0004. This study included an analysis of the estimated increase in air
pollutant emissions (both criteria pollutants and hazardous air pollutants) resulting from the
increased truck traffic necessary to transport urea to FCPP for use by the SCR system. EPA also
summarized these in the TSD for our proposed rulemaking.
Based on the study included as Appendix A to the TSD, EPA determined that the adverse
impacts associated with the use of SCR at FCPP, using urea as planned by the facility, are
extremely low. This is particularly true in light of the very large reductions in emissions of NOx
(over 33,000 tpy) and concomitant improvements in air quality that would be achieved. In
addition, it should be noted that under the supplemental proposal, NOx emissions will be reduced
by a greater amount, and less urea will have to be transported to the facility due to the closure of
Units 1-3.
Although EPA has concluded, based on indications from APS that it intends to use urea
for SCR, that it is most appropriate to consider the impacts of urea and not anhydrous ammonia,
we note that ammonia is one of the most used chemical commodities in the United States, with
large amounts transported annually by train, truck, and barge. Most ammonia is used as a
fertilizer, including anhydrous ammonia for direct application.49
49 See http://minerals.usgs.gov/minerals/pubs/commodity/nitrogen/mcs-2011-nitro.pdf.
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If APS instead chose to transport and store anhydrous ammonia rather than urea, the
commenter is correct that the transport and storage of anhydrous ammonia would require
development of a Risk Management Plan and Process Safety Management plan by both the
power plant and the transfer facility at the rail line. For the transfer facility, these are normal
costs of doing business and the associated costs would be included in the cost of anhydrous
ammonia as delivered to the facility. Similarly, the cost to the facility is a known cost of using
anhydrous ammonia which must be weighed in the decision of which SCR reagent to use at any
given facility. In any case, the costs of complying with these programs would likely be a small
fraction of the total costs related to the use of SCR at a facility.
Comment:
One private citizen (0163/0164/0216) submitted a study of coal combustion and
respiratory health near Shiprock, NM which primarily addresses the impact on indoor air of coal
combustion inside homes for warmth. The commenter cited information in the report to support
his assertion that at a site located 2 km from FCPP, the concentration of trace metals in the
outdoor air was equivalent to the concentration inside where there was a broken stove leaking
coal exhaust. According to the commenter, people living 2 km around the power plant might
have to be evacuated because outdoor air is equivalent to inside a home with a leaking stove.
Two private citizens (0149, 0158) expressed concern about open storage of fly ash at
FCPP, which they stated contain toxic heavy metals.
Response:
Any near-plant exposure to trace metals as particulate matter is more likely to be a result
offugitive emissions offly ash or coal dust from power plants than from exposure to the stack
exhaust. The stacks at FCPP release the exhaust at a high elevation for the purpose of
preventing excessive concentration ofpollutants in the immediate vicinity of the plant.50 Trace
constituents of coal can become emitted as HAPs when the coal is combusted; therefore the dust
generatedfrom handling coal should also be expected to contain trace metals. In the stack
exhaust, many HAPs exist as, or are associated with, particulate matter (PM). EPA has recently
promulgated a final rule regulating HAPs from coal fired electric generating units in the MATS
rule. FCPP is required to comply with the MATS rule. The MATS rule sets emission limits for
PM from units like those operating at FCPP. In general, PM and HAPs that are removed from
the exhaust by a control device become fly ash, thus, it is reasonable to expect fly ash to also
contain HAPs. Many coal fired utilities need to upgrade their PM controls to remove the HAPs
from the exhaust gas to meet the MATS emission limits. However, it is likely that the existing
baghouses on Units 4 and 5 already provide adequate emissions control to meet the PM
concentration limit in the MATS rule. Because the baghouse and scrubbers are removing HAPs
from the exhaust gas from Units 4 and 5, we would anticipate that HAPs will end up in the fly
ash and scrubber waste at FCPP.
50 EPA Good Engineering Practice (GEP) http://www.epa.gov/scram001/guidance/guide/gep.pdf
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Although the windblown fly ash and coal dust from FCPP are likely to contain HAPs,
EPA does not have any data regarding the specific concentrations of HAPs around FCPP. The
concentration of the HAPs indoors from a leaking coal fired stove would likely be at a
significantly higher concentration than in any windblown ash or dust. The emissions from a
leaking coal fired stove are entirely uncontrolled while more than 99% of the PMin FCPP stack
exhaust is removed by the baghouses for Units 4 and 5. Further, the HAPs emissions from a
leaking indoor stove would likely be substantially more concentrated than the stack emissions
from FCPP because the HAPS are emitted into a relatively small volume of air relative to the
stack emissions from FCPP.
To address the fly ash and coal dust emissions at FCPP, EPA promulgated a FIP in May
2007 that required FCPP to ensure that opacity from its fly ash and coal dust material handling
and storage operations never exceeded 20% opacity. Imposing an opacity limit and requiring a
dust control plan are reasonable approaches for assuring adequate control of these emissions.
Although EPA has the authority to impose such a requirement under the TAR as necessary or
appropriate, EPA 's 2007 FIP did not provide an adequate justification that the opacity limit was
necessary or appropriate. When APS petitionedfor judicial review of this opacity limit
provision, EPA determined that we had not provided an adequate justification for the provision.
Therefore, EPA requested the 10th Circuit Court of Appeals to remand the 20% opacity limit for
material handling operations to EPA for a fuller explanation andjustification. At the time, EPA
indicated that it would provide this additional basis for the regulation in a later rulemaking.
In this rule, EPA is now finalizing a requirement for FCPP to ensure that opacity from its
material handling operations does not exceed 20%. This limitation is necessary or appropriate
to limit PM emissions from fly ash and coal dust material handling and storage operations. The
necessity of limiting these PM emissions is to protect the NAAQS, may also provide a surrogate
for limiting HAPs. EPA 's action to protect the NAAQS by limiting PM emissions, enforceable
through establishing a 20% opacity limitation on fly ash and coal handling and storage
operations, is widely supported by comments on our proposal. Moreover, such a limitation is
consistent with requirements for dust-generating activities in neighboring Arizona.51 For more
details on EPA 's justification for including an opacity limit see our response in Section 10.
Comment:
One public advocacy group (0112) stated that EPA should strongly assert to the
management of FCPP that they have a responsibility to improve on public health effects as well
as visibility impacts. According to the commenter, the operator of FCPP has been asserting at
public meetings and with the media that the EPA proposals for FCPP are only about visibility
and have no relationship to public health. The commenter stated that this is a misleading
assertion by the company.
Response:
51 For example, see Maricopa County Air Quality Department Rule 310: Fugitive Dust from Dust-Generating
Operations that sets an opacity limit of 20%. See
http://www.maricopa.gov/aq/divisions/planning_analysis/AdoptedRules.aspx
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As previously mentioned, the RHR is meant to address visibility impacts at nearby
National Parks and Wilderness areas. However, reductions in N0X and PM emissions from
FCPP can also improve air quality and reduce health impacts.
Comment:
One public advocacy group (0112) disagreed with the statement in the TSD that impacts
to water quality will not be considered because FCPP is not a zero water pollutant discharge site.
The commenter indicated that FCPP holds a 1993 NPDES Permit No. NM0000019, which is still
in force based on an EPA Region 9 Administrative Extension granted on or about April 6, 2006.
The commenter asserted, therefore, that it is imperative to consider water quality impacts.
The commenter (0112) added that EPA has missed an opportunity to reduce the waste of
13.3 million gallons of water per day, which is currently used by FCPP for cooling steam
condensers and not returned to the San Juan River system. The commenter stated that the use of
closed system dry cooling towers at FCPP would greatly reduce water use. According to the
commenter, the withdrawal of such large quantities of water from tributaries of the Colorado
River has contributed to the need for large federal salt removal expenditures costing many
millions of dollars from 1976 to the present.
Response:
EPA disagrees with the commenter that it is imperative to consider water quality impacts
of BART controls for NOx. In our TSD, under Factor 3 - Energy and non-air quality
environmental impacts, we explain that APS did not consider impacts to water quality in its
analysis because FCPP has not been identified as a facility that is not allowed to discharge
water (i.e., as stated by the commenter and in our TSD, FCPP is not a zero water pollutant
discharge site). In other words, FCPP does discharge water, as evidenced by its Clean Water
Act NPDES permit that is currently under an administrative extension that regulates its
discharges to Morgan Lake and its cooling water intake. As such, water quality impacts related
to the cooling system at FCPP is regulated by EPA under a different authority (Clean Water Act)
than the Regional Haze and BART Requirements (Clean Air Act). The BART Guidelines cite
several examples of a non-air quality environmental impact, e.g., water availability may affect
feasibility and cost of wet scrubbers, or wet scrubber (for controlling SO 2) may affect water
quality and land use. The installation and operation of SCR would not significantly affect water
quality or water discharges from FCPP.
This rule is not requiring increased water consumption associated with SO2 control
because EPA found that the SO 2 controls from the previous rulemaking in 2007 (72 FR 25698,
May 7, 2007) are adequate. If EPA was requiring scrubbers that increased water consumption it
would be considered under the non-air quality related environmental impacts.
EPA also disagrees with the commenter that EPA has missed an opportunity to reduce
water use at FCPP for its cooling system. EPA does not have authority under the RHR to require
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retrofit of its cooling water system. EPA notes that a transition from a wet cooling system to a
dry cooling system requires energy, reducing the energy efficiency of the power plant. EPA
further notes that the alternative emission control scenario, which allows APS the option to close
Units 1 3 in lieu of complying with BART, would reduce water use by 6,000 acre feet per year,
as described in our Supplemental Proposal.
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5.0 Comments on Factor Three - Existing Controls at FCPP
Comment:
One of the owners of FCPP (0176/0177) agreed with EPA's summary of the existing
controls at the plant, but noted that the proposed FIP is only the most recent action in a long line
of regulatory and voluntary efforts to reduce emissions of pollutants that impact visibility,
including SO2, NOx, and PM emissions. The commenter asserted that FCPP has a strong history
of retrofitting pollution controls and recounted the facility's history of installing these controls
and reducing emissions.
Response:
EPA agrees that there have been numerous installations of pollution controls over the
several decades that FCPP has been in operation. The most recent voluntary effort by FCPP
increased the SO2 removal from its long-term level of 72% removal to 88% removal. This was
accomplished before the end of2004 and became effective as a regulatory requirement in June
2007. The improvement in SO 2 removal resulted in a decrease of over 22,000 tons of SO 2 per
year since that time.
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6.0 Comments on Factor Four - Remaining Useful Life of FCPP
Comment:
One of the owners of FCPP (0176/0177) noted that the BART rules state that the normal
amortization period (20 years for NOx control devices) is appropriate in applying the remaining-
useful-life BART if the plant's "remaining useful life will clearly exceed" that amortization
period (citing 70 FR 39169). The commenter asserted, however, that as a result of substantial
uncertainty related to multiple factors, it is not at all clear that the plant's remaining useful life is
at least 20 years. Thus, the commenter asserted that EPA must give proper consideration in its
analyses to the possibility of a shorter useful life for FCPP. Moreover, according to the
commenter, one factor that should not be allowed to shorten the useful life under the BART rules
is the choice of BART itself - EPA cannot use a 20-year amortization period to justify a
specified technology (e.g., SCR) if the application of the technology would be so costly as to
make the facility uneconomical and shorten its useful life (citing 70 FR 39164, 39171). The
commenter made the following arguments related to the possibility of a shorter useful life at
FCPP:
• The excessive cost of SCR will dramatically increase the energy costs of the plant,
potentially making it uneconomical. The installation of SCR on Units 1-3, including bag
house retrofitting, would increase the cost of electricity production on a $/MWh basis by
more than 50 percent which, in conjunction with other market and regulatory
uncertainties, may make the units uneconomic. Retrofitting SCR on Units 4 and 5 would
raise the cost of generation at those units by more than 25 percent, and there is a
reasonable possibility that such a cost increase would threaten the economic viability of
those units.
• The proposed "phase-in schedule" for SCRs may force closure of units because APS will
not have certainty by the compliance deadline that the lease will be extended or that
SCE's ownership share will have been successfully transitioned. Numerous approvals
must be obtained to allow any of the units at FCPP to continue to operate, including
Units 4 and 5; securing each of these approvals takes time and presents risk. In particular,
APS must obtain federal grants of right-of-way from DOI pursuant to 25 U.S.C. 323,
which constitute "federal actions" that are likely to trigger review under the National
Environmental Policy Act, possibly taking several years. Thus, APS would have to make
significant capital expenditures on Units 1-3 before obtaining the needed approvals, and
would instead close the units.
• The proposed FIP would require retrofitting BART controls on Units 1-3 much sooner
than the time allowed under the Regional Haze regulations, which is 5 years. This is
unreasonable in that APS must allow time for a final decision to be made on the proposed
SCE transaction before making the substantial capital expenditures to retrofit Units 1-3.
A requirement to install SCR and baghouses on those three units in such a short time
would likely lead to increased engineering and installation costs. APS needs the
flexibility of 5 full years to install SCR.
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• Emerging environmental laws and regulations present cost and operational uncertainty
that may shorten FCPP's useful life. These include potential new GHG laws and
regulations, a Maximum Achievable Control Technology (MACT) standard for EGUs,
new ash-handling requirements, and new requirements for cooling water intake
structures.
Another of the FCPP owners (0174) cited the comments above to argue that EPA's
economic analysis should have considered shorter "payback periods" because a reduced payback
period could result in FCPP power (with SCR costs included) exceeding wholesale market costs.
Response:
EPA disagrees with commenters that we must consider a shorter useful life because of
uncertainty related the factors cited by the commenter. It is inappropriate to consider a useful
life shorter than 20 years based solely on a possibility of shut down. EPA further notes that in its
FCPP cost analysis on behalf of APS, B&V stated "the remaining useful life of Units 1 through 5
was at least 20 years 52 In our proposed BART determination, EPA described the analysis
conducted to examine the competitiveness of FCPP compared to purchasing power on the open
market if SCR were required on all five units at FCPP and determined that if SCR were applied
on all units at FCPP, the cost to produce electricity at FCPP would still be lower than the cost to
purchase power on the open market. Unless there is an enforceable obligation for APS to cease
operations on a given date or unless APS convincingly demonstrates that controls (rather than
uncertainly associated with future requirements) will cause facility closure, the default 20 year
amortization period represents the appropriate period for the remaining useful life.
In our proposed BART determination for FCPP, EPA proposed a PM emission limit for
Units 1 — 3 that can be achieved through the installation of any offour different PM control
options. EPA did not prescribe which PM control APS must use to comply with the proposed
limit. Wet membrane electrostatic precipitators (ESPs) represented the least costly option, while
baghouses represented the most costly option. At the time of our BART proposal, the Mercury
and Air Toxics Standard (MATS Rule) for electric utility steam generating units had not yet been
proposed, nor had APS suggested its alternative emission control strategy to close Units 1 3 in
lieu of complying with BARTfor NOx. Because the MATS rule is now final53, and EPA is
finalizing the option to allow APS to either comply with the alternative emission control strategy
or BART, EPA is not taking action at this time on our proposal to set new PM limits for Units 1 -
3. Therefore, the comment that installation of baghouses in addition to SCR on Units 1-3 will
increase the cost of power by approximately 50 percent is not relevant.
While the commenter's suggested increase in the cost ofpower from Units 4 and 5 as a
result of SCR (25 percent increase) is reasonably consistent with the results of the EPA analysis
(22 percent) with respect to the power cost impact of SCR on all five FCPP units, it must be
noted that the original EPA analysis did not evaluate SCR on Units 4 and 5 exclusively. For
more information on cost of SCR on units 4 and 5 see our response above in Section 4.1.2.
52 See B&V Engineering Analysis for Units 1 - 5 at FCPP dated December 2007. Document number 0011 in docket
for proposed rulemaking: EPA-R09-OAR-2010-0683.
53 77 FR 9304, February 16, 2012.
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EPA agrees that the phased-in schedule for installation of SCRs on Unit 13 for BART,
which was added in the supplemental proposal, may have allowed only 2 years for engineering
and installation of these pollution controls from the date by which APS intends to make its
decision on continuing operation or shutting the units down by 2014. EPA is changing the
schedule for SCR installation by requiring the SCRs for either Unit 4 or 5 to be installed within 4
years of the effective date of this rule and the remaining Units (Units 1-3 and the either 4 or 5)
within 5 years of the effective date.
With respect to the "paybackperiod" referenced by the commenter, EPA's analysis did
not identify "payback periods. " Rather, the commenter appears to be referring to the 25-year
period utilizedfor the discounted cash flow calculations within the model. Nevertheless, EPA
does not disagree with the commenter's stated concern that shorter plant life (as may be
precipitated by other possible emerging regulations unrelated to Regional Haze), and thus
shorter discounting periods, would yield different economic results. However, EPA disagrees
with commenters that a shorter useful life should be considered in the economic analysis because
consideration of other regulations are outside the scope of the Regional Haze BART analysis.
Comment:
One industry commenter (0117) stated that EPA, rather than evaluate APS's
supplemental proposal as an alternative emission control strategy, should instead "re-determine"
BART for each of the five units at FCPP based on the APS-proposed shutdown scenario for
Units 1-3. The commenter noted that consideration of the shortened remaining useful lives of
Units 1-3 could result in a determination that BART for these units is no additional control
prior to shutdown, while consideration of the remaining useful lives of Units 4 and 5 would not
be heavily weighted since they are not to be shut down in the near term. The commenter
concluded that a "better-than-BART" control strategy does not seem to be necessary for
determining the appropriate requirements for FCPP under the APS-proposed shutdown scenario;
instead, a BART determination for each unit with appropriate weighting of the statutory factors
appears to present a logical and less-burdensome means of applying section 169A(b)(2) of the
CAA to FCPP.
Response:
EPA disagrees with the commenter's suggestion that APS's supplemental proposal
should be evaluated in terms of a BART-redetermination rather than in terms of its current status
as a "better-than-BART" alternative measure. EPA has met its obligation under 40 CFR
51.308(e)(1) by performing a BART determination for FCPP in accordance with 40 CFR 51,
Appendix Y (Guidelines for BART Determinations Under the RHR). We do not consider a re-
determination of BART that takes into account APS's supplemental proposal the most
appropriate methodfor evaluating APS' proposal in light of the "alternative measure "
provisions contained in 40 CFR 51.308(e)(2) and (3). The 2006 RHR (71FR 60612) specifically
established the procedures described in 40 CFR 51.308(e)(2) and (3) for scenarios involving
programs that may make greater reasonable progress than source-by-source BART. These
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provisions were specifically included to allow for the flexibility to consider alternative measures
such as the one proposed by APS, and EPA considers it the most appropriate method for
evaluating APS's supplemental proposal.
Comment:
One industry commenter (0117) discussed the "remaining useful life" statutory factor,
noting that under the BART Guidelines remaining useful life is ignored in the majority of BART
determinations (citing 40 CFR part 51, Appendix Y, section IV.D.4.k), which the commenter
alleged is inappropriate. According to the commenter, Congress designated the remaining useful
life of the source as an important consideration because it did not want to impose the burdens of
control technology retrofits on sources that were more than 15 years old at the time the statute
was enacted. Given that it is now 34 years after the BART requirements were enacted, the
commenter stated that the "remaining useful life" statutory factor should weigh heavily in BART
determinations for older sources such as FCPP, instead of being ignored. See Section 10.0 for
more on this commenter's legal interpretation of the Regional Haze requirements.
Response:
EPA disagrees with the commenter that we ignored the "remaining useful life " statutory
factor in our BART decision. EPA considered this factor in our BART analysis (see pages 42-43
of the TSD). As discussed in the TSD the remaining useful life of an EGU subject to BART is
determined by the utility. EPA cannot arbitrarily decide that an EGU has less useful life when it
is not within our BART rulemaking authority to require closure of an EGU. If a utility used a
shorter useful life than one that would allow the full amortization of any necessary pollution
controls, EPA would take that into account in the cost analysis, provided that there was an
enforceable obligation that the EGU would cease operation by that time.
Comment:
One private citizen (0163/0164/0216) stated that it appears that APS is trying to keep its
workers from telling the truth about metal fatigue problems and major corrosion problems at
FCPP. The commenter noted that fly ash has sulfur in it which, when mixed with water, forms
sulfuric acid which can corrode iron pipe. The commenter included a newspaper article profiling
a manager at the plant which recounted an incident in which a pipeline transporting fly ash and
water at the plant burst. The commenter was apparently questioning whether the remaining
useful life of the plant is as much as 20 years as assumed in the BART analysis.
Another private citizen (0144) simply stated that FCPP has lived beyond its usefulness.
Response:
As mentioned in the previous comment, in general, the utility determines the appropriate
useful life of their EGUs subject to BART. Unless there is an enforceable obligation for APS to
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cease operations on a given date or unless APS convincingly demonstrates that controls (rather
than uncertainly associated with future requirements) will cause facility closure, the default 20
year amortization period represents the appropriate periodfor the remaining useful life.
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7.0 Comments on Factor Five - Anticipated Visibility
Improvements
Comment:
One of the owners of FCPP (0176/0177) presented information on visibility conditions on
the Colorado Plateau and the role of NOx emissions in Western visibility impairment. The
commenter noted that SO2 and NOx emissions have been decreasing in recent years and cited a
status report prepared by the Western Regional Air Partnership (WRAP) stating that (1) visibility
has been improving at the Class I areas on the Colorado Plateau, (2) fire is the dominant
contributor to haze on the 20 percent worst visibility days, (3) the sulfate contribution to haze is
steadily decreasing, and (4) significant improvement can be seen on the 20 percent best visibility
days. The commenter also presented information that purported to show that whether averaged
over the haziest 20 percent of days, the clearest 20 percent of days, or all days, power plant NOx
emissions contribute less than 1.5 percent to the light extinction at Mesa Verde National Park.
Another of the FCPP owners (0168) cited this comment and emphasized this last point. A utility
industry association (0169) also presented information to show that less than 1.5 percent of light
extinction at Mesa Verde National Park is the result of power plant NOx emissions.
Another commenter (0223) questioned EPA's assertion that that NOx and PM from FCPP
are significant contributors to visibility impairment in the numerous mandatory Class I areas
surrounding FCPP (citing 75 FR 64221), stating that coal-fired power plants, including FCPP,
are relatively small contributors to regional haze in the surrounding Class I Areas. According to
the commenter, the WRAP has concluded that visibility impairment caused by PM and
attributable to all stationary sources is probably less than 2 percent, and that stationary source
NOx emissions probably cause between 2 and 5 percent of the visibility impairment on the
Colorado Plateau.
In contrast, the comments of an environmental advocacy group (0182) included a quote
from EPA's Section 110 proposed rule for the San Juan Generating Station stating, "NOx and
SO2 are significant contributors to visibility impairment in and around New Mexico. As the Four
Corners Task Force notes, '[r]eduction of NOx is particularly important to improve visibility at
Mesa Verde National Park.... [Visibility has degraded at Mesa Verde over the past decade, and
the portion of degradation due to nitrate has increased....'".
Response:
EPA modeling of FCPP showed visibility impacts from 1.2 to 6.0 deciviews, depending
on the Class I area, with the sum of impacts at all sixteen Class I areas totaling 43 deciviews.
This is a significant contribution to visibility impairment. Even if an individual source category
appears small by itself the many segments of the emissions inventory together cause significant
visibility impairment and must be addressed in order to make progress towards the national goal
of remedying visibility impairment from manmade pollution. Section 169A of the Clean Air Act
requires BART determinations on BART-eligible EGUs regardless of trends or ambient visibility
conditions. Application of BART is one means by which we can ensure that downward emission
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and visibility impairment trends continue. EPA identifies stationary sources as an important
category to evaluate in a BART analysis.
Comment:
Three of the owners of FCPP (0168, 0174, 0176/0177, 0179), a group of owners (0185),
the Navajo Nation (0223), and two utility industry associations (0169, 0187) argued that EPA's
use of Interagency Workgroup on Air Quality Modeling (IWAQM) Phase II default background
ammonia values is not appropriate. In extensive comments drawing heavily on a report by
Dr. Ivar Tombach that was appended to the comments, one of the owners of FCPP (0176/0177)
argued the following:
• Actual field measurements show lower ammonia concentrations than used by EPA.
• The EPA is mistaken in its assumption that background ammonia concentrations along
the path of the plant's plume determine nitrate concentrations and their contribution to
haze at the receptor site.
• The EPA's "corroborating" approach of "back-calculating" ammonia is flawed because it
erroneously assumes that the ammonia associated with measured sulfate and nitrate
would all be available to react with FCPP emissions, whereas in reality those
measurements reflect emissions from many sources.
• The EPA's analysis of nitrate predictions as a check on the ammonia values used is also
flawed because it erroneously assumes that the resulting measured nitrate levels are
solely due to FCPP emissions, whereas in reality they reflect emissions from many
sources. A comparable analysis using the EPA ammonia value shows substantial and
"physically impossible" overpredictions of nitrate.
• The sensitivity analysis carried out for APS of the alternate ammonia concentrations in
the CALPUFF model demonstrates that the ammonia values AECOM used in its
modeling are valid and correct.
One of the utility industry associations (0187) and the group of FCPP owners (0185)
similarly stated that for EPA to reject the body of direct measurements of ammonia concentration
in the FCPP region, it must provide substantial scientific justification, which it has not done.
These commenters also stated that EPA's supplemental sensitivity analysis was flawed because it
consists almost entirely of modeling conducted using the "discredited" back-calculation method,
which the commenter alleged is as insufficient for this purpose as it was for setting the
background ammonia levels directly. The commenters concluded that the use of IWAQM values
invalidates EPA's BART modeling and the BART determination based upon it. Other of the
FCPP owners (0168, 0179) stated that APS provided ample justification for using its proposed
lower background ammonia levels and successfully refuted EPA's arguments for using IWAQM
default value. Accordingly, the commenters requested that EPA accept the visibility modeling
using the lower variable background ammonia values, which will significantly reduce the
visibility benefits ascribed to SCR.
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Another utility industry association (0169) stated that several measurement programs on
the Colorado Plateau show that actual ammonia values in Class I areas near FCPP are
significantly lower than the IWAQM default value, indicating that these values typically range
from 0.1 to 0.6 ppb.54 The commenter noted that ammonia concentrations are lowest during the
cold season when the visibility impacts of NOx emissions are the highest. Accordingly, the
commenter asserted that using a single ammonia value throughout the year is not scientifically
valid and should be replaced with seasonally variable values. The commenter stated that
modeling with "valid, accurate" ammonia values will show significantly lower visibility changes
resulting from SCR at FCPP.
The Navajo Nation (0223) expressed concern regarding discrepancies between EPA and
APS modeling inputs, given the commenter's understanding that APS obtained advance EPA
approval for its modeling protocols. The commenter expressed a preference for using recorded
data wherever possible and noted difficulties associated with estimating background ammonia
levels and the CALPUFF model, citing the discussion in the initial proposal (75 FR 64226) and
the associated TSD for our proposed BART determination (pages 70-72). The commenter argued
that EPA's use of various sensitivity analyses in support of the use of the IWAQM default and
then corroborating with revised background ammonia data further complicates the modeling
protocols. The commenter alleged that this approach is fundamentally flawed. Some commenters
stated that EPA had earlier agreed to lower ammonia concentrations, and so should not be using
the higher IWAQM value now.
A utility industry association (0169) speculated that cost effectiveness in terms of dollars
per deciview improved resulting from retrofitting FCPP with SCR (based on modeling using
CALPUFF version 6.4 and "valid" background ammonia values) would be an order of
magnitude higher that the $17 million per deciview benchmark that the commenter ascribed to
EPA's TSD. Accordingly, the commenter asserted that SCR cannot be justified as BART at
FCPP.
In contrast, one public interest advocacy group (0112) concurred with EPA's back-
calculation method for ammonia background levels (citing the TSD, page 60). The commenter
added that the requests to EPA from other commenters for additional ammonia monitoring data
are unrealistic in today's budget environment. The commenter agreed with EPA's statement in
the TSD that initiation of a new monitoring program would be a much larger undertaking than
the analysis procedures described in the BART Guidelines.
Response:
EPA disagrees with commenter objections to the background ammonia concentrations
used in our modeling. Our use of the 1 ppb IWAQM Phase II default background ammonia
54 The commenter (0169.1) cited "Baseline ambient gaseous ammonia concentrations in the Four Corners area and
eastern Oklahoma, USA" by Mark E. Sather, Johnson Matthew, Nghia Nguyen, et al., Journal of Environmental
Monitoring, Vol. 10 (2008), pp. 1319-1325; Ammonia measurement data provided by Dr. Jeff Collett of Colorado
State University; and "Measurements of Ambient Background Ammonia on the Colorado Plateau and Visibility
Modeling Implications," I. Tombach and R. Paine, contributors, Report by Salt River Project, Phoenix, Arizona,
September 2010.
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value is appropriate. Most of the objections have already been discussed in EPA 's TSD for the
proposal; and several of them concern the "back-calculation " method that we used only as
corroboration for the 1 ppb results we principally relied on. Also, even if the lower ammonia
concentrations urged by some commenters were accepted, EPA's sensitivity modeling results
provided in the TSD for our proposed BART determination showed the visibility benefits would
still support EPA's BART determination. EPA also provided the results of modeling runs that
used the lower ammonia background concentrations recommended by some commenters (see
TSD Table 37). The visibility benefits of the proposed N0X controls for BART are substantial
under all ammonia scenarios, including the lower background ammonia concentrations
recommended by commenters. For 12 Class I areas, modeling even with those lower
backgrounds showed benefits of 0.5 dv or more, an amount recognized in the BART Guidelines
as significant (e.g. at 70 FR 39120).
The lack of measurements of ammonia and ammonium in the Class I areas of concern
requires that EPA estimate background ammonia concentrations by some method, considering
available data and approaches. As discussed in the BART proposal and its accompanying TSD,
EPA understands that there is no single accepted methodfor estimating the background
concentration of ammonia, and that any method will have advantages and disadvantages. The
lack of consensus on a method was a factor in EPA's decision to rely on the 1 part per billion
(ppb) default value in IWAQM, as was the fact that IWAQM is the only available guidance on
this issue. In summary, there is insufficient monitoring information available to use a different
value, or to support any seasonally varying values.
On issue (1), field measurements cited by the commenters were not performed in the Four
Corners area, nor at the Class I areas near FCPP, so they do not necessarily give appropriate
ammonia background concentrations for modeling of FCPP. In addition, the studies provide
only gaseous ammonia (NH3) and not ammonium (NH4) that has reacted with SO2 or N0X
emissions. For purposes of assessing FCPP impacts relative to natural background, per the
BART Guidelines, both ammonia and ammonium should be assumed to be available to interact
with emissions from FCPP. The ammonia-only measurements cited by the commenters
underestimate the available ammonia. Finally, as discussed in the TSD, field measurements in
the Four Corners area showed ammonia measurements ranging from 1.0 ppb to 1.5 ppb, and
sometimes as high as 3.5 ppb.55 This provides some additional support for the 1 ppb used by
EPA.
On issue (2), in using a 1 ppb background EPA did not rely on an assumption about the
importance of background ammonia along the path of the plume, as claimed by the commenters.
The 1 ppb background is representative of areas in the west under existing EPA guidance, in the
IWAQM document. The commenters' objection is based on the rapidity of the nitrate-nitric acid
equilibrium, which they state implies that ammonium nitrate can only be estimated using
ammonia measurements right at the Class I area, and not the ammonia that occurs earlier along
the plume's path to the area. EPA 's TSD for the proposed rulemaking did state (TSD p. 62) that
the Federal Land Managers partly relied on this assumption as one of the rationales for the
back-calculation method, discussed below; EPA also expressed support for the idea that the
55 Mark E. Sather el al., 2008. "Baseline ambient gaseous ammonia concentrations in the Four Corners area and
eastern Oklahoma, USA". Journal of Environmental Monitoring, 2008, 10, 1319-1325, DOI: 10.1039/b807984f
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method can be viewed as a 24-hour temporal integration, not just a spatial integration over the
plume path, and that this aspect can be viewed as desirable for the 24-hour average visibility
estimate that CALPUFFprovides (TSD pp. 71-72). This plausibility argument applies despite the
rapid nitrate-nitric acid equilibrium cited by the commenters, and in any case was not relied on
by EPA in using the 1 ppb default ammonia background.
As the commenters stated under issue (3), EPA used a back-calculation ammonia estimation
method as an alternative that provides some corroboration for the 1 ppb IWAQM method, and
which is more fully explained in the TSD for the proposal. Essentially, it uses measured
particulate ammonium sulfate and nitrate to estimate the amount of ammonia that must have
been present to form those ammonia compounds. The commenters object that the method
assumes that all the calculated ammonia is available to interact with the FCPP plume as
background ammonia. However, this assumption is reasonable for the single-source CALPUFF
modeling performed under the BART Guidelines. It estimates ammonia concentrations that
would be monitored at the Class I area if only this single source existed; it includes ammonia
that is currently in the form of ammonium because of interaction with other sources' emissions.
It remains true that some portion of the calculated ammonia would in reality not be available for
FCPP, because it arrives at the monitor from a different direction than FCPP's pollutant plume;
on the other hand, the data would also include directions contributing below-average ammonia,
reducing that effect.
In addition, the back-calculated ammonia is based on measurements only of particulate
ammonium, the form associated with measured sulfate and nitrate; it does not include any
gaseous ammonia that may also be present. In this sense, the back-calculated ammonia is a
lower bound on the ammonia that may be available to interact with source emissions; that is, the
method may underestimate ammonia concentrations. This possible underestimation tends to
offset possible overestimation discussed above.
EPA does not claim that the back-calculation method is dispositive; it incorporates
various assumptions and imperfections that make clear it is only an estimate. However, it is
based on real measured data at Class I areas, and has some counterbalancing tendencies for
over- and under-estimation. After weighing various lines of argument about the back-calculation
method, EPA disagrees with the commenters who recommended that it be rejected altogether.
The method provides a useful estimate of ammonia for BART modeling, by providing
concentrations representative of the high values that would be observed at the Class I areas in
the absence of other sources. On balance, EPA believes the back-calculation provides a
reasonable corroborating methodfor selecting the appropriate ammonia background to use.
In issue (4) the commenters claim that the assumption of full availability to FCPP of the
back-calculated ammonia invalidates EPA 's comparison of monitored nitrate levels with those
modeled using the back-calculated ammonia (TSD p. 73). As just discussedfor issue (3), EPA
disagrees that the assumption is invalidfor corroboration of single-source BART assessment
modeling. For single-source BART modeling, on balance, it is reasonable to assume all the
ammonia is available to the source, given the counterbalancing tendencies for over- and
underestimation inherent in the back-calculation method discussed above. In any case, this
method mainly provided corroboration for the results from using the 1 ppb ammonia default. The
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related issue (5) about "'physically impossible " nitrate over-predictions does not account for the
fact that any model evaluation is expected to have under- and over-predictions, depending on the
meteorological conditions and the geographic location modeled, as well as on the location of the
monitor usedfor comparison. While consistent over-prediction in a full model performance
evaluation would indeed raise concerns over its validity, as EPA stated, our nitrate comparison
was not intended as a model performance evaluation, but rather as a "rough check" for the
back-calculation corroboratory method (TSD p. 73). EPA found that the modeled and monitored
values, for both the maximum values and the 98th percentiles, were generally in agreement.
Finally, contrary to the commenter 's assertion, EPA did not receive a modeling protocol
in advance of modeling by APS's contractor. EPA disagrees with commenters that EPA
committed to use the same ammonia concentrations used by APS's contractor in our own
modeling analysis for our BART determination.
Comment:
Three of the owners of FCPP (0168, 0176/0177, 0179) and a utility industry association
(0169) asserted that CALPUFF version 5.8 used in the EPA's BART analysis is outdated. Some
of these commenters stated that past EPA statements make clear that the BART analysis should
be based on the best application currently available to predict visibility impacts (citing 70 FR
39121-23). Because of enhancements to the model's chemistry, the commenters stated that
CALPUFF version 6.4 represents the best application that is currently available. A number of the
commenters mentioned a December 2010 meeting between the CALPUFF developer and the
FLMs where the FLMs reportedly supported an expedited review and approval of CALPUFF
version 6.4.
One of these commenters (0168) stated that it is extremely concerning that EPA would
impose a requirement costing a facility hundreds of millions of dollars based on results from the
"regulatory version" of a model when a newer, more accurate version of the model is available.
Another of the commenters (0179) stated that EPA should re-run its FCPP visibility modeling
using CALPUFF version 6.4 and the seasonally adjusted background ammonia levels developed
by APS's modeling contractor or accept the APS modeling analysis using these tools. A third
commenter (0169) similarly indicated that EPA should revise its BART analysis using actual
measured background ammonia values and CALPUFF version 6.4.
Another of these commenters (0176/0177) presented the results of comparison tests
purported to show that version 6.4 produced results that more closely matched measured values
than did version 5.8. (The commenter appended the report of these comparison tests to the
comments.) This commenter (0176/0177) also presented the results (APS comment, attached
Exhibit F) of comparative modeling carried out for FCPP using CALPUFF versions 5.8 and 6.4,
and three different background ammonia levels (IWAQM default, CMAQ model-derived, and
the AECOM values). This modeling showed that the predicted visibility impacts (in terms of dv)
decline significantly from CALPUFF version 5.8 to version 6.4 for all three background
ammonia values used in the model runs.
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The commenter concluded that the emission limitations specified in the proposed FIP will
not result in any perceptible visibility improvements at any of the 16 Class I areas in the Four
Corners region. [Two of the other owners of FCPP (0168, 0179) and a utility industry association
(0169) also stated this conclusion.] The commenter stressed that this is not a surprising result
given that studies have shown that power plant NOx emissions comprise a de minimis
contribution to the observed visibility conditions as Mesa Verde National Park.
The commenter (0176/0177) added that these results are confirmed by a multi-year
regional air quality study carried out for the Four Corners Air Quality Task Force by Environ,
which concluded in August 2009. This study used the CAMx model and predicted even less
visibility improvement at Mesa Verde from the application of SCR at FCPP and nearby San Juan
Generating Station than did AECOM's modeling with CALPUFF version 6.4 using the AECOM
values for background ammonia concentrations. Another of the owners of FCPP (0168) also
cited this as confirming evidence.
Using the modeling results based on CALPUFF version 6.4 and the AECOM background
ammonia concentrations, and its own control cost analysis, the commenter (0176/0177)
calculated the cost effectiveness of combustion controls and SCR in terms of dollars per dv
improved at Mesa Verde. According to the commenter, the cost effectiveness of advanced
combustion controls would be about $64 million per dv and SCR would be about $365 million
per dv. The commenter stated that in its TSD, EPA indicated that $17 million per deciview is a
reasonable benchmark for a cost-effective BART control technology. Based on this cost
effectiveness metric, the commenter concluded that advance combustion controls constitute
BART for FCPP.
Another owner of FCPP (0174) stated that the version of CALPUFF used by EPA has a
tendency to over-predict nitrate concentrations, which is compounded by EPA's use of what the
commenter asserted are overestimated ammonia background values. The commenter stated that
this combination of errors results in a significant over-prediction of visibility improvements for
more stringent NOx BART control options. Further, the commenter stated that this
disproportionately affects the incremental visibility benefits predicted for SCR over LNB
compared to LNB over baseline. The commenter supported the related comments submitted by
Commenter 0176/0177 and stated that the modeling results submitted by that commenter should
be used to determine BART.
In contrast, one federal agency (0175) was generally supportive of the modeling methods
employed by EPA with the regulatory approved version 5.8 of the CALPUFF modeling system.
This commenter noted that in email correspondence dated December 22, 2010 from Mr. Robert
Paine to Mr. Scott Bohning, there is a specific reference to a meeting held between Mr. Joe Scire
and the FLMs regarding CALPUFF version 6.4, indicating that the FLMs were "pleased to
receive this presentation and will be working to 'expedite' the review and implementation for
this improved version of CALPUFF." The commenter stated for the record that its agency was
not represented at the December 10, 2010 meeting and has not officially endorsed or committed
to expediting the review and implementation of this version of the CALPUFF system. Moreover,
it remains the commenter's position that until this version has undergone a scientific peer review,
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model code review, and more rigorous performance evaluation than presented, this version
should not be used for regulatory purposes.
Response:
EPA disagrees with the commenters that any new CALPUFF version should be usedfor
the BART determination. EPA relied on version 5.8 of CALPUFF because it is the EPA-
approved version in accordance with the Guideline on Air Quality Models ("GAQM", 40 CFR
51, Appendix W, section 6.2.1.e); EPA updated the specific version to be usedfor regulatory
purposes on June 29, 2007, including minor revisions as of that date; the approved CALPUFF
modeling system includes CALPUFF version 5.8, level 070623, and CALMET version 5.8 level
070623. CALPUFF version 5.8 has been thoroughly tested and evaluated, and has been shown
to perform consistent with the initially promulgated version from 2003 in the analytical
situations it has been approvedfor. Any other version would be considered an "alternative
model", subject to the provisions of GAQM section 3.2.2(b), requiring full model documentation,
peer-review, and performance evaluation. No such information for the later CALPUFF versions
that meet the requirements of section 3.2.2(b) has been submitted to or approved by EPA.
Experience has shown that when the full evaluation procedure is not followed, errors that are
not immediately apparent can be introduced along with new model features. For example,
changes introduced to CALMET to improve simulation of over-water convective mixing heights
caused their periodic collapse to zero, even over land, so that CALPUFF concentration
estimates were no longer reliable.
In addition, the latest version of CALPUFF, 6.4, incorporates a detailed treatment of
chemistry. EPA's promulgation of CALPUFF (68 FR 18440, April 15, 2003) as a "preferred"
model approved it for use in analyses of Prevention of Significant Deterioration increment
consumption andfor complex wind situations, neither of which involve chemical
transformations. For visibility impact analyses, which do involve chemical transformations,
CALPUFF is considered a "screening" model, rather than a "preferred" model; this
"screening" status is also described in the preamble to the BART Guidelines (at 70 FR 39123,
July 6, 2005). The change to CALPUFF 6.4 is not a simple model update to address bug fixes,
but a significant change in the model science that requires its own rulemaking with public notice
and comment.
Furthermore, it should be noted that the US Forest Service and EPA review of
CALPUFF version 6.4 results for a limited set of BART applications showed that differences in
its results from those of version 5.8 are driven by two input assumptions and not associated with
the chemistry changes in 6.4. Use of the so-called "full" ammonia limiting method andfiner
horizontal grid resolution are the primary drivers in the predicted differences in modeled
visibility impacts between the model versions. These input assumptions have been previously
reviewed by EPA and the FLMs and have been rejected based on lack of documentation,
inadequate peer review, and lack of technical justification and validation.
EPA intends to conduct a comprehensive evaluation of the latest CALPUFF version along with
other "chemistry" air quality models in consultation with the Federal Land Managers, including
a full statistical performance evaluation, verification of its scientific basis, determination of
whether the underlying science has been incorporated into the modeling system correctly, and
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evaluation of the effect on the regulatory framework for its use, including in New Source Review
permitting. CALPUFF version 5.8 has already gone through this comprehensive evaluation
process and remains the EPA-approved version, and is thus the appropriate version for EPA 's
BART determination for FCPP.
Comment:
The Navajo Nation (0223) expressed concern about the accuracy of CALPUFF based on
a 2010 study that concluded that the closure of Mojave Generating Station had resulted in no
perceptible visibility improvement in Grand Canyon National Park, despite predictions based on
CALPUFF modeling that visibility in the park would improve.56 According to the commenter,
the study's authors concluded that their results raise questions about the reliability of CALPUFF.
The commenter found this uncertainly alarming given that CALPUFF is the model used for the
FCPP BART analysis and the significant economic impacts that the commenter alleged the
BART determination could have on the Navajo Nation if FCPP were to shut down rather than
install emission controls. (See Section 4.1 for the comments on potential economic impact.)
Response:
As discussed in the response to the previous comment, EPA affirms that the regulatory
version of CALPUFF is the correct model to use for this BART determination.
The study cited by the commenters raises issues that should be considered as EPA revisits
visibility modeling in consultation with the Federal Land Managers. It found significant
decreases in sulfate and nitrate concentrations after the closure of the Mojave Generating
Station, but little improvement in associated visibility impairment. The authors tried to eliminate
other possible causes for this; however, they state "This is partially explained by fluctuation in
other aerosols masking the drop in sulfate. It is also possible that the sulfate change is too small
relative to natural daily variation in visibility conditions to have a significant impact. ... Our
results indicate that other components of visibility, in particular coarse mass and nitrate,
changed in GCNP after the closure. ... These difficulties are indicative of a larger problem
encountered when attempting to conduct inference on a calculated parameter (like deciviews)
which is itself a function of many stochastic processes, each governed by a unique set of
anthropogenic and natural factors. " While not downplaying the quality and importance of this
work, CALPUFF 5.8 is adequate for BART determinations; regulatory use of later versions must
await their full EPA evaluation.
Comment:
One federal agency (0175) sought clarification of the nature of the comparison between
the APS BART alternative CALPUFF modeling and the EPA BART modeling that was
presented in Table 8 in the supplemental proposal (citing 76 FR 10538-39). The commenter
56 The commenter cited "Effect of Coal-fired Power Generation on Visibility in a Nearby National Park,"
44 Atmospheric Environment 2524, Jonathan Terhorst and Mark Berkman, 2010.
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noted that correspondence from APS AECOM to EPA Region 9 staff dated December 23, 2010
indicates that the "model combinations are CALPUFF v5.8 and also v6.4 with two sets of
ammonia backgrounds...The commenter wished to make certain that the data presented in
Table 8 is a direct comparison of modeling results using the APS BART alternative proposal to
the October 19, 2010 EPA BART modeling using CALPUFF version 5.8 and is not a
combination of version 5.8 and version 6.4 of CALPUFF.
Response:
To clarify, although APS provided documentation modeling results using both CALPUFF
versions, the EPA proposals and technical support documents presented only results from
version 5.8, the approved regulatory model.
Comment:
Some commenters (0168, 0174, 0176/0177, 0179, 0185, 0187) argued against the
visibility metrics that EPA introduced in the BART proposal. These comments are summarized
below.
One of the owners of FCPP (0176/0177) argued that the new visibility metrics proposed
in the ANPR are inappropriate and unsupported, and should be discarded. The commenter noted
that none of the metrics (percent improvement in dv impacts, cumulative changes in dv, and dv
impacts scaled by the geographic area of the affected Class I area) are addressed in the BART
rules, and posited that their introduction into the BART process is intended to inflate the
estimated visibility benefits of the control options at FCPP. In addition, the commenter noted that
these metrics do not appear to have been subjected to peer review or public comment
independent of this rulemaking, as would be normal for what the commenter stated to be a
critical change to a defined regulatory process.
Regarding the percent improvement metric, the commenter (0176/0177) stated that these
values (unlike values of the haze index in dv) have no consistent relationship to the human
perception of haze changes and no consistent relationship to changes in ambient visibility-
impairing particle concentrations. As a result, the commenter asserted that this metric is not
appropriate and must be rejected. For similar reasons, a utility industry association commenter
(0187) and a group of FCPP owners (0185) asserted that the percent improvement metric does
not provide useful information for assessing visibility improvement and EPA cannot legitimately
rely on this method in making a BART determination.
Similarly, one of the owners of FCPP (0176/0177) contended that cumulative change in
dv is not an appropriate metric to describe visibility improvement and should be withdrawn. The
commenter made the following points:
• The peak impact from a source occurs at different times in different Class I areas because
a facility's emissions cannot result in peak concentrations in all directions at once. Thus,
this metric really does not represent a cumulative regional impact of the source (and
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hence the benefit of controls); rather it simply produces a mathematical summation of the
peak impacts occurring at different times at various Class I areas.
• The value of the total depends in part of the number of Class I areas included in the
analysis. This raises questions regarding the utility of the CALPUFF model when Class I
areas are at distances where the accuracy of CALPUFF is in question. The BART rule
notes that uncertainties in model performance increase at distances greater than 200 km
from the source (citing 70 FR 39125-26), and 10 of the 16 Class I areas evaluated for
FCPP are located more than 200 km from the plant. These 10 areas show some of the
highest modeled visibility improvements, and it is likely that these predictions are
overstated.
• It is inappropriate to add improvements over all Class I areas. A 0.5 dv improvement in
one Class I area and a 0.5 dv improvement in another area does not result in a 1 dv
improvement - the improvement is a 0.5 dv improvement, which occurs in two different
locations. Any one observer would experience only a 0.5 dv improvement; he or she can
only experience the visibility improvement in the Class I area being visited. Adding
improvements across Class I areas flies in the face of the basic science of visibility
perception thresholds.
The utility industry association (0187), one FCPP owner (0179), and a group of FCPP
owners (0185) also argued against use of the cumulative impact metric, which they asserted
dramatically overstates projected visibility improvements. These commenters claimed that the
cumulative approach contradicts the BART rules, which state that it is appropriate to model
impacts at the nearest Class I area and other nearby Class I areas "to determine whether effects at
those [other] areas may be greater than at the nearest Class I area," and that "[i]f the highest
modeled effects are observed at the nearest Class I area, you may choose not to analyze the other
Class I areas further" (citing 70 FR 39170). The commenters concluded from this that the BART
rules envisage a visibility analysis that is focused on visibility impacts in the most impacted area,
not all areas. The commenters added that cumulative impact is inappropriate because no
individual will perceive impacts in more than one Class I area at a time. The commenters also
said this approach arbitrarily inflates the benefit that might be associated with emissions
limitations at a single source, illustrating this point by noting that this method would yield
different results if a Class I area were divided into two or more areas - increasing the benefit
simply by increasing the number of areas. One of these commenters (0187) also pointed out that
this approach would equate a small, imperceptible benefit summed over more than one area with
a much larger, humanly perceptible improvement in a single area, which the commenter stated
are not equivalent.
Two other owners of FCPP (0168, 0174) voiced general support for the comments on
visibility metrics submitted by Commenter 0176/0177.
Conversely, one environmental advocacy group commenter supported the use of a
cumulative impact analysis. The commenter asserted that the cumulative impact of a source's
emissions on visibility, as well as the cumulative benefit of emission reductions, is a necessary
consideration as part of the fifth step in the BART analysis, particularly in cases such as FCPP
where the source causes or contributes to visibility impairment at a significant number of Class I
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areas. The commenter stated that failing to account for a source's cumulative impairment and the
cumulative pollution control benefit would result in a failure to acknowledge the regional
approach to reducing haze.
Response:
EPA believes that it is important to consider the visibility impact on multiple Class I
areas. The goal of the visibility program is to remedy visibility impairment at all Class I areas.
CAA 169A (a)(1). One approach to account for the benefits to all affected Class I areas is the
cumulative "total dv" metric. However, there is no EPA approved cumulative metric to account
for visibility impacts at multiple Class I areas. EPA relied on the modeled impacts and benefits
at each Class I area individually, the number of Class I areas affected, and also considered, but
did not specifically rely on, the sum of visibility impacts and benefits across all sixteen Class I
areas.
The comments about the visibility metrics have largely already been addressed by EPA in
the TSD for our proposed BART determination (pp. 61-6 3 and pp. 67-68), which also explained
that EPA did not rely on any alternative visibility metrics in the BART determination. The
comments on this issue are therefore moot, but we will briefly summarize the issues, which are
discussed more fully in the TSD.
As for the percent deciview visibility improvements that some commenters objected to,
EPA refers the commenters to the proposal TSD, which explains what it represents for visibility
impacts (TSD for proposed BART determination, p. 62). EPA understands, and is confident that
the commenters understand, the difference between absolute numbers and percentages. In brief,
the percent improvement for a particular area and control scenario shows only the relative
improvement in the impact of FCPP alone, and not improvements in overall visibility
impairment. A given absolute deciview improvement translates into a large percent
improvement at an area having only a small FCPP impact in the first place, and a small percent
improvement at an area having a large FCPP baseline impact. EPA notes that the BART
Guidelines do mention percent improvement as a legitimate metric.57 EPA considered this
information qualitatively, but arrived at conclusions about the degree of visibility improvement
in terms of deciviews, in accordance with the BART Guidelines (75 FR 64229, and TSD p. 76).
Finally, EPA disagrees with the commenters that EPA is restricted to considering only
impacts at the single nearest Class I area, or the single Class I area with the highest impacts. A
somewhat fuller excerpt from the commenters' citation of 70 FR 39162 is: "One important
element of the protocol is in establishing the receptors that will be used in the model. ... you
may choose not to analyze the other Class I areas any further as additional analyses might be
unwarranted. " When read in context, this language in the BART Guidelines is clearly meant to
provide a common sense approach to streamlining a complex and difficult modeling exercise
where "an analysis may add a significant resource burden to a State. " 70 FR at 39126. While
the BART Guidelines indicate that a detailed analysis of the visibility impacts at each area in a
cluster of Class I areas may not be necessary, this is not because the visibility impacts at Class I
57 70 FR 39170 "Comparison thresholds can be used in a number of ways in evaluating visibility improvement (e.g.
...a threshold representing an x percent change in improvement). "
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areas other than the most impacted are irrelevant but rather because the visibility benefits at the
most impacted Class I area alone may be sufficient to justify the selection of the most stringent
control technology as BART. Where, as here, the benefits of controls have been modeledfor a
number of surrounding areas and consideration of these benefits is useful in determining the
appropriate level of controls, EPA does not agree that these benefits should be ignored.
Comment:
Two commenters (0174, 0187) questioned EPA's use of 0.5 dv as the threshold of a
humanly perceptible change in visibility (citing 75 FR 64228). One of the commenters (0187)
cited scientific literature, while the second (0174) cited the report by Dr. Ivar Tombach that is
attached to Comment 0176/0177. The latter commenter (0174) added that the establishment of a
specific deciview threshold as a "bright line" to define whether a certain control will be imposed
as BART is contrary to the intent of the BART rules and the objectives of the Regional Haze
program, which require EPA to consider the cost of each control option in relation to the
associated visibility benefit.
One of the owners of FCPP (0176/0177) expressed the belief that application of SCR at
FCPP would result in no perceptible visibility improvement and therefore cannot be BART. The
commenter based this conclusion on modeling results discussed previously in this section. Based
on these results, the commenter stated that the changes in visibility that would result from
combustion controls and SCR are all humanly imperceptible, as is the difference between
combustion controls and SCR - thus, there is no basis for concluding that SCR constitutes
BART. Am. Corn Growers, 491 F.3d at 7 (rejecting EPA's position, as reflected in the original
BART rules, that allowed for the possibility "that a source may be forced to spend millions of
dollars for a new technology that will have no appreciable effect on haze in any Class I area.").
Response:
EPA disagrees with the commenters that the visibility benefit from the proposed BART
controls is too small to warrant requiring the controls; in addition, EPA is not using a
perceptibility threshold in this BART determination. EPA agrees that thresholds should not be
considered a "bright line " in making BART decisions. In the BART Guidelines, EPA described 1
dv as the thresholdfor an impact that "causes" visibility impairment, and 0.5 dv as a threshold
for an impact that "contributes " to visibility impairment, for determining whether a source is
subject to BART, though States were accorded discretion to use different thresholds (70 FR
39118, July 6, 2005; also 39120-39121). These thresholds do not apply to BART determinations
for sources have been found subject to BART; States or EPA could consider visibility impacts
less than 0.5 dv to warrant BART controls. To the extent that the comment is questioning the
BART eligibility of FCPP, EPA has already established that FCPP is BART eligible and the
commenter did not provide evidence to the contrary.
Even if the commenters are correct that 0.5 dv change is not perceptible, EPA noted that
"/e/ven though the visibility improvement from an individual source may not be perceptible, it
should still be considered in setting BART because the contribution to haze may be significant
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relative to other source contributions in the Class I area. Thus, we disagree that the degree of
improvement should be contingent upon perceptibility. Failing to consider less-than-perceptible
contributions to visibility impairment would ignore the CAA's intent to have BART requirements
apply to sources that contribute to, as well as cause, such impairment. " (70 FR 39129)
That is, impacts smaller than this to contribute to impairment. Conversely, an
improvement of 0.5 dv or less contributes to improvement in visibility impairment. As stated in
the proposal, the modeled improvements in visibility are large enough to warrant requiring the
proposed BART controls. While the actual improvements may be larger, from 0.6 to 2.8
deciviews, even an improvement of 0.5 dv is a contribution toward improving visibility,
especially when the benefits at multiple Class I areas are considered. In conjunction with
improvements from other sources, this will help toward the Clean Air Act goal of remedying
manmade visibility impairment.
Comment:
One environmental advocacy group commenter (0182) stated that EPA underestimated
visibility improvement from installing NOx controls because it overestimates the production of
sulfuric acid by the SCR and underestimated the amount of sulfuric acid removed downstream of
the SCR. The commenter cited reports attached to the comments (0182) to argue that sulfuric
acid does not limit SCRNOx control efficiency. The commenter also states that modeling shows
that greater NOx removal rates are not offset by sulfuric acid emissions but instead yield greater
visibility improvements than those proposed by EPA. The commenter argues that there will be a
significant visibility benefit from increasing the SCR NOx efficiency from 80 percent to 90
percent and therefore concludes that a higher level of NOx control than 80 percent should be
determined BART.
Response:
EPA disagrees with the comment that we overstated the production of sulfuric acidfrom
the SCR catalyst and underestimated the amount of sulfuric acid removed downstream of the
SCR. In the TSD for our proposed BART determination, we estimated sulfuric acid emissions
using the EPRI methodology and provided detailed explanations for all of the assumptions we
applied as well as a discussion to compare measured and calculated values of sulfuric acid
emissions from the Navajo Generating Station (see TSD p. 55-59, 64-65, and 68). While we fully
acknowledge and understand that the generalized EPRI methodology does not precisely
represent true sulfuric acid emissions for a given facility, this method is a commonly used
calculation methodology for estimating sulfuric acid emissions under a future operating scenario
involving SCR. The assumptions we applied in estimating sulfuric acid emissions after the
installation and operation of SCR using the EPRI methodology were justified and appropriate.
EPA assumed in our BART proposal a 3+1 system (4 layers of catalyst) would achieve
80% NOx removal. Greater reduction efficiencies would likely require an additional layer of
catalyst, which would likely increase sulfuric acid emissions. Based on the SO2 to SO3
conversion rate guarantee we receivedfrom Hitachi for its CX series catalyst (ultra-low
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conversion) of 0.167% per layer, the use of an additional catalyst layer would equal 5 layers of
catalyst and a 0.835% conversion rate. EPA is not aware of SCR systems that use 5 layers of
catalyst, and the addition of a 5th layer would certainly affect the cost and operation of the unit.
Although EPA agrees that the modeling referenced by the commenters appears to indicate
greater visibility improvement from an SCR system achieving 90% removal compared to 80%
removal despite higher sulfuric acid emissions58, EPA does not agree that this requires EPA to
determine that 90% control be determined BART. In Section 8.1 of this document, we respond to
the comment that the emission limitation for BART should be based on 90% control with SCR
rather than 80% control with SCR. Based on the rationale outlined in that response, EPA
determined that 80% control, achievable with SCR, is appropriate for BART for FCPP.
Comment:
One of the owners of FCPP (0176/0177) submitted the results of additional modeling and
concluded that the proposed alternative strategy would result in greater visibility improvements
in the Class I areas surrounding FCPP than would the proposed BART FIP; however, the
commenter continued to disagree that the improvement would be humanly perceptible.
According to the commenter, the commenter's additional visibility modeling using "valid
background ammonia values and the revised CALPUFF model" show that none of the modeled
NOx emission reduction strategies at FCPP will result in humanly perceptible improvement in
visibility in the 16 surrounding Class I areas. The commenter indicated that highest predicted
visibility improvement (change in deciview) by applying SCR, compared to baseline emissions,
is 0.28 dv, while the incremental improvement in dv resulting from application of advanced
combustion control technology and SCR is predicted to be 0.21 dv. Because both these numbers
are well below the EPA-threshold for human perception of 1.0 dv, SCR does not constitute
BART for the Plant.
Response:
EPA agrees with the commenter that the alternative emission control strategy (of
shutting down units 1, 2, and 3, and placing SCR on units 4 and 5) may "result in greater
visibility improvement at the surrounding Class I areas " (EPA's supplemental proposal, 76 FR
10532, February 25, 2011). However, as discussed in the response to another comment, EPA
does not agree that the visibility improvement from the original or alternative NOx reduction
strategies would be imperceptible; EPA anticipates the improvements from either strategy would
be perceptible.
Comment:
One of the owners of FCPP (0176/0177) stated that EPA's TSD Table 21 (TSD p.44)
mischaracterized the measured visibility impairment at nearby Class I areas as 10th and 90th
58 EPA notes that the baghouses on Units 4 and 5 are assumed to provide a significant amount of control of sulfuric
acid emissions, therefore, such slight increases in sulfuric acid emissions would not be expected on units that are not
equipped with baghouses.
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percentile deciview values, whereas the figures actually represent the average of deciviews on
the best and worst 20% of days, respectively. The commenter also pointed to contradictory
statements in the TSD (pp.46-47) about the maximum relative humidity used in the relative
humidity adjustment factor (f(RH))i\\a.i accounts for the effect of water on particle size growth:
the TSD states that the IMPROVE equation uses a maximum humidity of 98%, whereas
IMPROVE and the RHR actually use 95%.
Response:
EPA agrees with the commenter that in Table 21 of the TSD, we incorrectly identified the
measured values as the 10th and 90th percentile deciview impairment, rather than the average
deciview impairment on the best and worst 20% days. However, Table 21 was presented only for
background informational purposes and the values in that Table were not germane to nor relied
upon in our BART determination. EPA relied on Tables 36 39 to assess the anticipated
visibility improvement from controls under the final factor of the BART analysis. Even though
mislabeled, Table 21 does give a correct impression of the magnitude of visibility impairment.
The 98% humidity maximum is a value from an earlier guidance document; the value in the
Regional Haze guidance59 and correctly used in EPA's modeling was 95%. EPA also notes that
this maximum (RHMAX in the input for the CALPOST post-processor) is not directly used in the
visibility calculation method (MVISBK=6 in CALPOST) that was relied upon, and therefore was
adequate for the BART determination modeling.
59 "Guidance for Estimating Natural Visibility Conditions Under the Regional Haze Rule", EPA-454/B-03-005, EPA
2003, p.A-3.
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8.0 Comments on BART Determinations
8.1 Comments on the Proposed BART Determination for NOx
Comment:
A number of commenters, including owners of FCPP (0168, 0174, 0176/0177, 0179,
0185), the Navajo Nation (0223), and a utility industry association (0187), asserted that EPA's
BART analysis was inconsistent with its own regulations in that it did not give proper weight to
the "presumptive BART" limits for NOx that it established for EGUs through notice-and-
comment rulemaking (generally citing 70 FR 39104, July 6, 2005). The commenters noted that
these presumptive BART limits are based on the use of combustion controls, and that EPA had
considered and rejected establishing presumptive BART limits based on SCR.
In the most extensive comments on this topic, one of the commenters (0176/0177) made
the following points. The other commenters (0168, 0174, 0179, 0185, 0187, 0223) presented
arguments similar to some or all of these points.
• In establishing presumptive BART limits for NOx emissions from EGUs, EPA concluded
that combustion control-based presumptive limits "are extremely likely to be appropriate
for all greater than 750 MW power plants subject to BART" (a category that includes
FCPP), that they are "highly cost-effective controls," and that they "would result in
significant improvements in visibility and help to ensure reasonable progress toward the
national visibility goal (citing 70 FR 39131). Additionally, EPA has made clear that "the
presumptions represent a reasonable estimate of a stringent case BART..." (citing 71 FR
60612, 60619, Oct. 13, 2006).
• The EPA was not correct in stating in the proposal that in setting presumptive BART
limits, it "did not consider the question of what more stringent control technologies might
be appropriately determined to be BART" (citing 75 FR 64226). Rather, EPA's 2005
rules were clear that the Agency had considered - and rejected - establishing
presumptive BART limits based on SCR (citing 70 FR 39136). Thus, EPA established
through rulemaking that SCR is not an appropriate basis for presumptive BART limits
and that combustion controls should generally be deemed BART.
• In this context, a BART analysis must begin with and take into account the presumptive
BART limits and EPA's rationale for setting them. If a source is able to meet the limit
through the application of combustion controls, there should be an exceedingly strong
presumption that such controls constitute BART. This principle was further supported in
EPA guidance to the states, where EPA generally directs authorities to "require such
utility boilers to meet the [presumptive BART] limits..." and to consider requiring
technologies other than combustion controls only when combustion controls cannot meet
the presumptive limit (citing 70 FR 39171-72).
• In effect, the EPA's analytical approach disregarded the presumptive limits entirely. By
using a top-down approach in which it started its analysis by evaluating SCR and then
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determined that SCR is BART for FCPP, EPA never undertook an assessment of the
combustion control technologies that EPA deemed, through notice-and-comment
rulemaking, to constitute presumptive BART. (See Section 3.2 for additional comments
on the use of the top-down approach.)
• In its BART analysis, APS has demonstrated that each unit at FCPP can meet the
presumptive BART limits through the application of advanced combustion control
technologies. Therefore, EPA thus must make an exceedingly compelling case for SCR
as BART if it intends to proceed with the proposed BART determination, which it has not
done. To the contrary, it has done little more than to conclude that SCR is acceptable as
BART based on an unexamined and arbitrary assumption that other technologies are not.
• Under the BART rules, a deviation from presumptive BART, either upwards or
downwards, is authorized if an alternative control level is justified based on "careful
consideration of the statutory factors" (citing 70 FR 39131). However, EPA did not
carefully consider the BART factors and then conclude that an alternative to presumptive
BART limits is appropriate. Instead, EPA dismissed the presumptive BART limits before
even considering the BART factors.
• The EPA appears to have adopted a new standard for deviations from presumptive
BART, stating that presumptive BART controls are required "unless there are source-
specific circumstances that would justify a different conclusion" (citing 75 FR 64226).
Using this new standard, EPA dismissed presumptive BART prior to undertaking any
BART factor analysis and argued for post-combustion controls on the grounds that FCPP
"is the largest source of NOx emissions in the United States and ... is surrounded by
16 mandatory Class I areas" (citing 75 FR 64226). Rather than using an analysis of the
BART factors to support a non-presumptive BART limit, EPA dismissed presumptive
BART outright, based on factors not referenced anywhere in the BART rules.
Response:
EPA disagrees with the commenters' assertions that we did not give sufficient weight to
presumptive BART NOx limits, or that the BART determination for FCPP was performed in a
manner inconsistent with the RHR
As noted in other responses in this document, the presumptive NOx limits established in
the BART Guidelines are determined to be cost effective and appropriate for most units. The
establishment of presumptive BART limits, and the corresponding technology upon which those
limits are based upon, does not preclude states or EPA from setting limits that differ from those
presumptions. Indeed, the five statutory factors enumerated in the BART Guidelines provide the
mechanism for establishing different requirements. EPA 's site-specific five-factor analysis for
FCPP demonstrates that, in considering the expected remaining useful life of FCPP and the
existing controls, SCR is cost effective , results in the most visibility improvement of all feasible
control technologies, and does not cause energy or non-air quality environmental impacts that
warrant its elimination as the top control option. As a result, regardless of the appropriateness
of SCR as a control technology for most units on a national scale, or the extent to which EPA
considered SCR in establishing the presumptive limits, the site-specific five-factor analysis
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performedfor FCPP justifies a different N0X BART limit than the presumptive N0X BART limit.
We note the RHR states:
States, as a general matter, must require owners and operators of greater
than 750 MWpower plants to meet these BART emission limits. We are
establishing these requirements based on the consideration of certain
factors discussed below. Although we believe that these requirements are
extremely likely to be appropriate for all greater than 750 MW power
plants subject to BART, a State may establish different requirements if the
State can demonstrate that an alternative determination is justified based
on a consideration of the five statutory factors.
The RHR also states:
If, upon examination of an individual EGU, a State determines that a
different emission limit is appropriate based upon its analysis of the five
factors, then the State may apply a more or less stringent limit.
Therefore, the presumptive emission limits in the BART Guidelines are rebuttable. The
presumptive emission limits apply to power plants with a total generating capacity of 750 MW or
greater insofar as these sources are required to adopt emission limits at least as stringent as the
presumptive limits, unless after considering the five statutory factors, the State determines that
the presumptive emission limits are not appropriate. Moreover, the RHR and BART Guidelines
do not exempt states from a five factor BART analysis, and that BART analysis may result in a
determination of BART emission limits that are more or less stringent than the presumptive
emission limits for subject to BART sources. The RHR states:
For each source subject to BART, 40 CFR 51.308(e)(l)(ii)(A) requires
that States identify the level of control representing BART after
considering the factors set out in CAA section 169A(g), as follows:
States must identify the best system of continuous emission control
technology for each source subject to BART taking into account the
technology available, the costs of compliance, the energy and non-air
quality environmental impacts of compliance, any pollution control
equipment in use at the source, the remaining useful life of the source, and
the degree of visibility improvement that may be expected from available
control technology.
EPA disagrees with commenters' assertions that we disregarded presumptive N0X BART
limits entirely, and that we failed to evaluate combustion controls in any substantive manner.
Although we do not rely upon the numerical values of the presumptive N0X limits listed in the
BART Guidelines, the technological basis for presumptive NOx BART limits, such as the use of
combustion control technology, boiler type, and coal type, were considered in the site-specific
five-factor analysis. Combustion control technology was specifically considered as a potential
retrofit technology, and costs and visibility improvements associated with combustion controls
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were calculated and included in the TSD in order to provide a comparison to other N0X control
technologies. As a result, presumptive BART was not disregarded or dismissed during the N0X
BART determination process.
In addition, EPA disagrees that the rule directs authorities to consider non-combustion
control technology only when presumptive limits cannot be met using combustion control
technology. While a BART determination deviating from presumptive BART must be supported
by the results of the five-factor analysis, the rule does not restrict the ability of States (or in this
case, EPA) to initiate a five-factor analysis. Although the inability of a boiler to meet
presumptive NOxBART limits through the use of combustion control technology is described as
one circumstance in which a non-combustion control BART determination may be considered
(70 FR 39172), it does not preclude consideration of other circumstances, nor is it identified as a
qualifying thresholdfor performing a five-factor analysis, as commenters suggest.
Comment:
One of the owners of FCPP (0176/0177) stated that an agency is required to follow its
own rules, and that failure to do so makes its action unlawful and subject to vacatur, citing Way
of Life Television Network, Inc. v. FCC, 593 F.2d 1356, 1359 (D.C. Cir. 1979) ("[A]n agency's
failure to follow its own regulations is fatal to the deviant action.") The commenter asserted that
in this case, EPA must develop and use a BART evaluation methodology that properly accounts
for the presumptive BART limits (see above), an incremental cost effectiveness assessment (see
Section 3.2), an analysis of control costs as a function of visibility improvement (see
Section 3.3), and site-specific cost information (see Section 3.1) to develop lawful BART limits
for FCPP.
Response:
EPA disagrees that we have not followed our own rules in performing the NOx BART
determination for FCPP. We address the commenter's specific concerns as follows:
• Presumptive BART limits - As noted in responses above to comments on the presumptive
NOx limit and the cost effectiveness of the presumptive NOx limit, while we did not
propose that BARTfor FCPP was satisfied with the presumptive NOx BART limits, the
site-specific five-factor analysis we performed did account for the technological basis for
presumptive NOxBART limits, such as the use of combustion control technology, boiler
type, and coal type, and also examined the ability of combustion control technology to
meet the numerical presumptive NOx BART limits.
• Incremental cost effectiveness assessment - As described in the comment responses
written in Section 3.2, we agree with commenters that the BART Guidelines do
recommend consideration of incremental cost effectiveness and our BART analysis
performed such an assessment in accordance with the methodology described in the
BART Guidelines.
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• Analysis of control costs as a function of visibility improvement - As described in the
comment responses written in Section 3.1, although $/deciview is discussed as an
example of one element that may be considered when determining cost of compliance, we
do not regard it as a mandatory metric under the five-factor analysis. We considered
several other metrics, including total capital costs, annual costs, $/ton, and incremental
$/ton, and do not regard $/deciview as a useful metric to inform our decision at this time.
• Site specific cost information - As described in the comment responses written in Section
3.1, we disagree with the commenters' assertion that our cost analysis did not take into
account the site-specific cost information supplied by APS. As part of the line-by-line
analysis we performed (described in Section 3.1 responses) on the cost estimates
provided by APS, we ultimately incorporated most of the APS cost estimates in our final
SCR cost estimate. Our detailed, line-by-line analysis is included in the docket for this
rulemaking and provides an explanation for why we retained, modified, or rejected each
line item in the SCR cost estimate for each of the five units at FCPP.
Comment:
Two of the owners of FCPP (0168, 0176/0177) and the Navajo Nation (0223) asserted
that advanced combustion controls constitute BART for FCPP because such controls will result
in meaningful emission reductions and will contribute to reasonable progress toward visibility
improvement.
One of these commenters (0176/0177) noted that EPA has "determined that combustion
controls are not likely to be effective control technologies at FCPP" (citing 75 FR 64226). The
commenter alleged that EPA's determination is based on superficial analysis and is mistaken.
This commenter (0176/0177) cited Exhibit J to its comments on the ANPR,60 which contains a
detailed analysis of the use of LNB and OFA on FCPP's units. According to the commenter, this
analysis confirms that the use of advanced combustion controls on the five units at FCPP will
reduce plantwide NOx emissions by 34 percent and, for those units that are subject to
presumptive BART limits, the reductions more than satisfy the presumptive limits in the BART
rules.
Two of the commenters (0168, 0176/0177) added that considering that neither SCR nor
advanced combustion controls will produce humanly perceptible visibility improvements in the
nearby Class I areas (see the commenters' comments in Section 7.0) these NOx emission
reductions must constitute BART. The commenters indicated that this is true given that the
reductions meet presumptive BART and will make a contribution to reasonable progress toward
the national visibility goal. One of the commenters (0176/0177) added that this conclusion is
reinforced by the cost differential between the technologies and the other BART factors
discussed in the commenter's comments elsewhere in this document.
The Navajo Nation (0223) stated that a phased approach to emissions controls at FCPP,
beginning with combustion controls, is fully consistent with both the CAA and the RHR, and is
60 See item 11 from collection of documents titled "Comments on ANPRM 09 0598 APS Comments and Exhibits",
Document No. EPA-R09-OAR-2009-0598-0195.
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the approach that the EPA should take as a prudent trustee of the Navajo Nation. According to
the commenter, installing LNB and OF A as a first step in a phased approach to BART for the
FCPP (and NGS) would:
• Be consistent with the presumptive BART limits established in the BART Guidelines.
• Result in a more clearly fact driven process, by allowing all interested parties to review
recorded, not simply modeled, results at the next review phase.
• Aid in the resolution of disputes over the costs to install the emission control options
under consideration by providing the opportunity to review the actual costs incurred by
FCPP to install LNB and OF A. (The commenter noted that NGS completed installation
of LNB/OFA this year.)
• Provide a reasonable timeframe in which to resolve outstanding lease and ownership
issues that affect the productive life of FCPP (Factor 4).
This commenter (0223) added that the BART component of the CAA and RHR was
meant to provide for a measured response to emissions from aging power plants; thus, requiring
the most expensive controls is inconsistent with the law and regulations governing the BART
process. The commenter also emphasized that requiring a power plant over which EPA has
exclusive jurisdiction to bear a greater regulatory burden than similarly situated plants regulated
by the states is contrary to the purposes of the Act, the RHR, and to the economic interests of the
Navajo Nation.
Response:
As noted in the responses to comments in Section 3.3, EPA disagrees with the comment
that Exhibit J of APS's comments on the ANPR confirm that advanced combustion controls on
all five units at FCPP will reduce plant-wide NOx emissions by 34%. APS has provided
conflicting information regarding whether or not advanced combustion controls will be effective
at significantly reducing NOx emissions at FCPP. As outlined in the TSD for our 2010 BART
proposal, based on an independent report by Andover Technology Partners dated April 5,
200461, we have concluded that combustion controls will in fact not be effective at significantly
reducing NO x emissions at FCPP. Furthermore, independent of whether or not advanced
combustion controls will allow the FCPP units to achieve presumptive NOx BART limits, EPA
disagrees with the commenter's assertion that a unit's ability to meet presumptive BART
precludes a more stringent BART determination. As noted in a previous response to comment in
this section, while the inability of a boiler to meet presumptive NOx BART limits through the use
of combustion control technology is described as one circumstance in which a non-combustion
control BART determination may be considered (70 FR 39172), it is not identified as a qualifying
thresholdfor performing a five-factor BART determination.
EPA disagrees that SCR will not produce humanly perceptible impacts. As noted in
responses to comment in Section 7, visibility modeling performed by EPA of the impacts of SCR
installation at FCPP indicates visibility impacts from 1.2 to 6.0 deciviews, depending on the
Class I area (based upon IWAQM Phase 2 background ammonia value of 1 ppb). If low
61 See Document No. EPA-R09-OAR-2010-0683-0059.
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ammonia background values are used as recommended by some commenters, visibility impacts
range from 0.8 to 3.2 deciviews. Although the lower range of these less conservative modeling
results fall below the 1.0 deciview value commonly cited as the thresholdfor human
perceptibility, the range of impacts is not negligible.
EPA does agree with certain aspects of the Navajo Nation's comments regarding a
phased implementation strategy to attaining national visibility goals. In 40 CFR 51.308(f), States
are required to revise their regional haze implementation plans every ten years, which is a
process that involves evaluating their ability to attain reasonable progress goals and potentially
updating their long-term strategy for regional haze. The periodic revision requirement described
in 40 CFR 51.308(f), however, does not extend to the implementation plan for BART
requirements. The phased approach described by the Navajo Nation has certain benefits, and a
phased approach is incorporated into the alternative emission control strategy.
Comment:
Two federal agencies (0175, 0224)) and two groups of environmental advocacy groups
(0095, 0182) argued that the NOx emission limit for the units at FCPP should be 0.05 lb/MMBtu
based on the capabilities of SCR. Another environmental advocacy group (0183) stated that EPA
should reexamine the basis for determining the NOx limit and consider tighter NOx controls, but
did not specify what that tighter limit should be. The comments of the federal agencies are
summarized below, followed by those of the environmental advocacy groups.
The federal agency commenters (0175, 0224) stated that, given that BART is meant to
achieve the best possible emissions reductions, EPA should not base its emission limits on the
"minimum reduction expected from SCR, estimated by Hitachi Power Systems America" (citing
the TSD for our proposed BART determination) because real-world application of SCR indicates
that lower NOx emission limits are routinely reached. Regarding the emission limits for Units 4
and 5, the commenters noted that of the 20 cell burners with SCR in 2010, 12 had lower NOx
limits than proposed by EPA for FCPP, with 3 EGUs at less than 0.06 lb/MMBtu. Based on this
information, the original APS BART analysis of SCR at 0.06 lb/MMBtu (annual and 24-hour
average), and the "common knowledge" that SCR can achieve at least 90 percent reduction, the
commenters concluded that the installation of SCR at FCPP is capable of reducing annual NOx
emissions by 90 percent to 0.05 lb/MMBtu on an annual average basis.
One of the federal agency commenters (0224) specifically refuted the additional rationale
provided by EPA in the supplemental proposal for its 80 percent SCR efficiency estimate:
• The EPA took into account the degradation of the SCR catalyst over its lifetime and
calculated the emission limit to reflect the capability of the catalyst just prior to its
replacement on a 3-year cycle. According to the commenter (0224), modern SCRs are
typically designed with one or two spare catalyst layers to facilitate catalyst management
and account for catalyst degradation over time; the issue cited by EPA is not a technical
limitation on SCR, but is simply a cost item to be accounted for in the proper design and
operation of the SCR.
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• The EPA stated that pursuing N0X control efficiencies of greater than 80 percent on
Units 4 and 5 is limited by formation of H2SO4 from the SCR catalyst because the
additional layers of catalyst needed to increase NOx control efficiency would increase
emissions of H2SO4, most affecting nearby Mesa Verde National Park. The commenter
(0224) gave the following reasons why this argument is incorrect. (Commenter 0175 also
made similar points.)
- The EPA's statement "the presence of additional catalyst would result in higher
emissions of sulfuric acid" is unsupported. The EPA used the EPRI method for
estimating H2SO4 emissions. The only factor in the EPRI method that is related to the
SCR and affects H2SO4 generated by the catalyst is the catalyst oxidation rate, not the
volume, area, or number of catalyst layers as implied by EPA.
- The EPA statement that "Minimizing the formation of primary SO3/H2SO4 in the
catalyst bed is most important for visibility improvement at Mesa Verde National
Park, the closest Class I area to FCPP" is unsupported.
o The EPA's modeling results in the October 2010 TSD show that even with
increases in sulfate emissions from SCR installation, visibility improves at Mesa
Verde National Park and every other national park.
o The EPA appears to have assumed that at least one additional catalyst layer would
have to be added to the two layers assumed by APS, thus increasing H2SO4
emissions by 50 percent, but application of EPA's Control Cost Manual method
for estimating SCR catalyst volume indicates that increasing NOx removal
efficiency from 80 to 90 percent would require only a 14 percent increase in
catalyst volume. If one assumes that H2SO4 emissions are directly related to
catalyst volume, a 14 percent increase in catalyst volume would mean an increase
in sulfate emissions of 0.3 lb/hr, which is highly unlikely to have any appreciable
impact upon visibility when compared to the much greater NOx reductions. To
verify the potential visibility impact, EPA should model the 90 percent NOx
reduction scenario with its increased sulfate emissions.
• The EPA stated that the high ash content (approximately 25 percent) of the coal burned at
FCPP may adversely affect the capability of SCR to reach the highest end of the control
efficiency range without the use of additional layers of catalyst or more frequent catalyst
replacement. According to the commenter, this is not consistent with previous EPA
proposals for SCR emissions limits at facilities that use coal with similar ash content. For
Desert Rock power plant with coal at 23.4 percent ash, EPA issued a permit limiting
annual NOx emissions to 0.0385 lb/MMBtu, and EPA has recently proposed NOx BART
at 0.05 lb/MMBtu (30-day rolling average) at the nearby San Juan Generating Station
which burns local coal with 21.3 percent ash. Unless the FCCP ash contains some
unusual catalyst poison, the 25 percent ash content is not a technical feasibility issue that
would affect SCR effectiveness, but is a matter of proper SCR design, operation, and
maintenance.
This federal agency commenter (0224) also stated that NOx BART for Units 1-3 should
be 0.05 lb/MMBtu on an annual basis. The commenter noted that unsuccessful attempts to
reduce NOx emissions at FCPP with combustion controls occurred over a decade ago when this
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technology was not as fully developed as now, and pointed out that APS's BART analysis
concluded that such controls are technically feasible and would reduce NOx emissions
significantly. The commenter evaluated Clean Air Markets Division (CAMD) data for 2000 -
2009 and found 33 dry-bottom, wall-fired boilers with NOx emissions rates similar to FCPP
Units 1-3 (0.6 - 0.8 lb/MMBtu) that had been reduced to 0.4 lb/MMBtu or less by application of
modern combustion controls. The commenter asserted that because the typical approach is to
first reduce NOx emissions by combustion controls before adding SCR, these real-world CAMD
data support the belief that using combustion controls and SCR could reduce NOx at FCPP Units
1-3 to 0.05 lb/MMBtu on an annual basis.
One group of environmental advocacy groups (0182) made similar arguments in asserting
that a lower NOx limit is technically feasible and legally required as BART for FCPP. To support
this assertion, the commenter drew heavily on an attachment containing comments prepared by
Dr. Phyllis Fox62 This comment summary includes the comments presented by Commenter
0182; the reader may refer to the attachment (0182) for greater detail. Commenters also argued
that emission limits should be based on a rolling average of 30 successive boiler operating days.
The commenter (0182) argued that neither the BART proposal nor the supplemental
proposal represents the emission reduction capabilities of BART and thus fail to satisfy the
CAA. The commenter asserted that a lower limit of 0.05 lb/MMBtu for NOx over a 30-day
rolling average at each FCPP unit is technically feasible based on a combination of combustion
controls (LNB and OF A) and a 90-percent-efficient SCR.
The commenter (0182) noted that the definition of BART at 40 CFR 51.301 is "an
emission limitation based on the degree of reduction achievable through the application of the
best system of continuous emission reduction... " The commenter asserted that EPA picked
80 percent NOx removal because it was the minimum level of control estimated by Hitachi
(citing TSD pages 31 and 87), but selecting the lower end of a range quoted by a single vendor
when the EPA only asked for 80 percent removal efficiency does not satisfy the minimum
statutory requirements of BART.
The commenter (0182) also stated the EPA indicated that 80 percent removal is
appropriate because it provides the operator a margin of safety. However, the commenter stated
the definition of BART does not anticipate a margin of safety, asserting that arbitrarily adjusting
down the emission reduction that can be achieved by SCR from 90 percent to 80 percent violates
the requirement that BART emission limits be set based on the best removal system operated at
the optimal efficiency to eliminate visibility impairment.
The commenter (0182) asserted that modern SCRs are routinely designed and operated to
achieve 90 percent NOx control and that based on this well-accepted industry standard, NOx
control of at least 90 percent is BART. The commenter noted that the BART Guidelines at
40 CFR part 51, Appendix Y state, "In general, a commercially available control option will be
presumed applicable if it has been used on the same or a similar source type."
62 See item (2) in collection of documents titled "Public Comment_8 Environmental Groups (Barth)_Letter 5-2-11".
EPA-R09-OAR-2010-0683 -0182.
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The commenter (0182) also contended that LNB and OF A are feasible for all five units at
FCPP. The commenter rejected EPA's statement that it would be difficult to retrofit Units 4 and
5 with modern LNB technology (citing 76 FR 10534) and pointed out that the operator of FCPP
has stated that the combination of LNB and OF A is technically feasible for these units. The
commenter indicated that the use of LNB/OFA on Units 1-5 would reduce NOx emissions by
27 to 46 percent, making SCR with a removal efficiency of 90 percent sufficient to satisfy a
0.05 lb/MMBtu NOx limit.
The commenter (0182) argued that a 0.05 lb/MMBtu limit is consistent with EPA's
determinations elsewhere, such as for the San Juan Generating Station (proposed limit of
0.05 lbs/MMBtu, 30-day rolling average) and for Desert Rock (final permit limit of
0.035 lbs/MMBtu, 365-day rolling average). According to the commenter, an EPA-issued permit
containing a lower NOx limit creates a presumption of technical feasibility for purposes of BART
- the BART Guidelines at 40 CFR part 51, Appendix Y state that "if there is a permit requiring
the application of a certain technology or emission limit to be achieved for such technology, this
usually is sufficient justification for you to assume the technical feasibility of that technology or
emission limit."
According to the commenter (0182), EPA asserted that lower NOx limits were not
feasible for two reasons: (1) excessive formation of sulfuric acid mist, and (2) high ash content in
the FCPP coal supply. The commenter asserted that the formation of sulfuric acid mist is not
expected to be as high as claimed by EPA, and that independent air dispersion modeling
established that the actual formation of sulfuric acid mist does not cause a significant level of
visibility impairment in any case (citing an attached report by Andrew Gray63). The commenter
added that the ash content of FCPP's coal (25%) is not significantly higher than other coals
where EPA imposed a lower NOx limit, such as at the San Juan Generating Station. The
commenter concluded that a lower BART limit is technically feasible and legally required.
In "preliminary" comments submitted prior to the supplemental proposal, a similar group
of environmental advocacy groups (0095) suggested NOx limits of 0.05 lb/MMBtu on a 30-day
rolling average measured using continuous emission monitoring system (CEMS), with
compliance in 2014. The commenter added that the BART determination should include a
provision that FCPP may forego BART implementation at any unit if it agrees to retire that unit
prior to the deadline for BART implementation. The commenter requested that these limits be
published for comment in any Federal Register notice published to take comment on the FCPP
alternative BART proposal.
Another environmental advocacy group (0183) argued that EPA should reexamine its
basis for determining NOx BART, believing that SCR likely can achieve greater than 80 percent
efficiency (EPA's assumed efficiency) and a lower emission rate at FCPP. The commenter noted
that the BART analysis submitted by the facility found SCR with approximately 90 percent
removal efficiency to be feasible, resulting in an emission rate of 0.06 lb/MMBtu for Units 2-5.
The commenter stated that EPA should reexamine its consideration of catalyst life, H2SO4
63 See item (5) in collection of documents titled "Public Comment_8 Environmental Groups (Barth)_Letter 5-2-11".
EPA-R09-OAR-2010-0683 -0182.
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formation, and ash content of the coal by comparing its assumptions with other coal-fired power
plants with similar parameters, and should establish a rigorous NOx limit reflecting BART.
Response:
EPA disagrees with the commenter's assertion that emission limits associated with BART
must meet the lowest emission rate achieved with that technology at any coal-fired power plant.
The Regional Haze Regulations at 40 CFR §51.308(e)(l)(ii)(A) state that:
The determination of BART must be based on an analysis of the best system of
continuous emission control technology available and associated emission
reductions achievable for each BART-eligible source that is subject to BART. . .
Additionally, the BART Guidelines state that: "[i]n assessing the capability of the control
alternative, latitude exists to consider special circumstances pertinent to the specific source
under review, or regarding the prior application of the control alternative ", (70 FR at 39166)
and that "[tjo complete the BART process, you must establish enforceable emission limits that
reflect the BART requirements ..." (70 FR at 39172). The five-factor BART analysis described
in the Guidelines is a case-by-case analysis that considers site specific factors in assessing the
best technology for continuous emission controls. After a technology is determined as BART, the
BART Guidelines require establishment of an emission limit that reflects the BART requirements,
but does not specify that the emission limit must represent the maximum level of control achieved
by the technology selected as BART. The BART Guidelines and the RHR do not preclude
selection of the maximum level of control achieved by a given technology as BART, however, the
emission limit set to reflect BART must be achievable by the specific source and should be
determined based on consideration of site-specific factors. Therefore, limits set as BACT during
PSD review (e.g., Desert Rock), or emission rates achievedfrom the operation of individual
facilities under an emissions trading program (e.g., Clean Air Act Interstate Rule (CAIR)) may
provide important information, but should not be construed to automatically represent the most
appropriate BART limit representative of a given technology for a given facility.
While some commenters asserted that combustion controls would be feasible upstream of
SCR to further reduce NOx emissions to meet a limit of 0.05 Ib/MMBtu, in its comment letter, the
National Park Service agreed with EPA that the addition of combustion controls such as OFA
may "not (be) worth the small incremental reduction in NOx emissions", based on its review of
the CAMD database showing that of the 35 cell burner boilers, only eight had combustion
controls, and that two cell burner boilers at Hatsfield Ferry were retrofit with OFA in 2001 and
2003 with minimal NOx reductions.64 As discussed in the TSD for our proposed BART
determination, because additional combustion controls atFCPP would not achieve significant
reductions in NOx and may cause operability issues for the boilers, EPA determined that SCR,
without the addition of new combustion controls, is BARTfor FCPP.
64 See page 1 of the attachment (titled "National Park Service Comments on EPA's February 25, 2011 BART
Proposal for the Four Corners Power Plant, April 22, 2011 AS REVISED MAY 17, 2011") to document titled "DOI
Resubmission of Comments on EPA BART Four Corners Navajo Nation_7-l 1-11", EPA-R09-OAR-2010-0683-
0224.
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A consortium of several environmental organizations (0182) argued that a 30-day rolling
average emission limit of 0.05 Ib/MMBtu should be determined BART for FCPP, based on a
final report written by Dr. Phyllis Fox.65 In Table 10 CAMD Maximum Rolling Averages
(2006 - 2010) Calendar-Day Basis of her final report, Dr. Fox argued that because 3 of the 20
best performing units achieved a maximum 30-day calendar average emission rate of 0.05
Ib/MMBtu (rounded to 1 decimal place), that 0.05 Ib/MMBtu is the appropriate BART limit for
FCPP. As stated above, EPA disagrees that an emission limit set in association with a BART
determination must represent the lowest achieved emission rate from the best performing unit
using that technology. EPA further notes that the maximum 30-day calendar average emission
rates for the 17 other top performing units listed in Table 10 of the commenter 's report exhibited
significant variability (0.056 - 1.1 Ib/MMBtu), even though the annual average emission rates
listed are all below 0.07 Ib/MMBtu.
In its comments, NPSprovided examples of 3 cell burner boilers currently equipped with
SCR: Cardinal Units 1 and 2 and Belews Creek Unit 1. In the context of an annual average limit,
however, examination of the 30-day calendar average emission rates is also informative. Based
on N0X data from the Clean Air Markets Division (CAMD), EPA notes that over 2009 - 2011
(January - June 2011), N0X emissions from Cardinal Unit 1 showed an increasing trend, with
minimum 30-day calendar average N0X emission rates increasing from 0.025 to 0.033 to 0.043
Ib/MMBtu in 2009, 2010, and 2011, and maximum 30-day calendar average N0X emission rates
increasing from 0.04966 to 0.052 to 0.065 Ib/MMBtu in 2009, 2010, and 2011.67 The CAMD data
show that Cardinal Unit 2 had numerous days of non-operation during 2009 - 2011, so 30-day
calendar average values were generally higher. However, if we exclude 30-day calendar
averages that were clearly affected by nearly a full month of non-operation68, Cardinal Unit 2
shows a similar pattern as Unit 1, with an increasing trend in minimum (0.021, 0.043, 0.051
Ib/MMBtu) and maximum 30-day calendar averages over 2009 - 2011 (0.056, 0.074, 0.076
Ib/MMBtu). Belews Creek 1 also showed a similar pattern of generally increasing minimum
(0.027, 0.040 and 0.041 Ib/MMBtu) andmaximum (0.078, 0.099, 0.094 Ib/MMBtu) 30-day
calendar average emission rates over 2009 - 2011, with the highest maximum 30-day average in
2010 of0.0989 Ib/MMBtu. Although commenters are correct in stating that the best performing
units can achieve 30-day rolling emission rates of 0.05 Ib/MMBtu or lower, CAMD data show
significant variability in emission rates, both over time for a given unit, and between the best
performing units. Some of this variability may be related to catalyst aging, or may be related to
the participation of these units in trading programs (therefore these units operate without an
absolute limit on individual boilers). Regardless of the cause of this variability, EPA notes that
significant variability over a 30-day average, even among the best performing units, does exist,
and EPA disagrees that an emission limit set in association with a BART determination must
65 See items (2 and 3) in collection of documents titled "Public Comment_8 Environmental Groups (Barth)_Letter 5-
2-11". EPA-RO9-OAR-2010-0683-0182.
66 For Cardinal Unit 1, to be more indicative of normal operation, EPA excluded the monthly emission rate from
May 2009 of 0.085 because it represented just one day of partial operation during the month of May. Unit 1 was not
operated for the remainder of May 2009.
67 See tab titled "with SCR" in spreadsheet titled "Cellburners CAMD CAIR.xlsx" in docket for this final
rulemaking.
68 For Cardinal Unit 2, to be more indicative of normal operation, EPA excluded the monthly emission rate from
March and November in 2009, and April in 2011.
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represent the lowest rate achieved on 30-day rolling average basis from the best performing unit
using that technology.
Commenters recommended that EPA set the 30-day rolling average limit based on a
boiler operating day (BOD), which would serve to average out emission spikes better than a
calendar average (especially spikes that are caused by a single operating day experiencing
shutdown in a calendar month), suggesting that higher limits to accommodate these emission
spikes are not needed. Commenters assert that extreme values in the 30-day calendar averages
reported by CAMD, in particular, those that are controlled by a very limited number of
operating hours in a calendar month, will be dampened by application of the 30-BOD rolling
average, but we note that significant variability still exists despite the application of a 30-BOD
rolling average. EPA agrees that the emission limit should be based on a 30 BOD for the BART
alternative option identified in the supplemental proposal. The 30-calendar-day average was
inadvertently carried over from the original proposal. We do find that the 30-calendar-day
average for the plant-wide average NOx BART determination is the appropriate approach for
this limit. All hours of operation of all of the units go into this plant-wide average and it is
appropriate to base this on a rolling 30-calendar-day basis.
Over the 2009 - 2010 period examined in Exhibit 14 to item 2 of comment number 0182,
the 30-BOD rolling averages calculated by Dr. Fox for Cardinal Unit 3 shows a range of 0.028
Ib/MMBtu to 0.065 Ib/MMBtu, with reported 1-year (2010) and 2-year (2009 - 2010) averages
of0.048 Ib/MMBtu. The 30-BOD rolling averages for Cardinal Unit 3 also show a general
increasing trend in actual emission rates over the two year period of2009 - 2010. For Havana
Unit 9, which commenters cited as the best performing unit achieving a 30 calendar day rolling
average of 0.05 Ib/MMBtu in 2010 and a 365-day rolling calendar average of0.036 Ib/MMBtu,
Dr. Fox calculated 30-BOD rolling averages over 2006 - 2010 that exhibited a significant range
of0.022 to 0.067 Ib/MMBtu. N0X emission rates over 2006 to early 2009 appear to exhibit
seasonal variability that may be related to active operator management of the SCR system (lower
emission rates during the summer ozone season and higher emission rates during the non-ozone
season). However, over 2009 - 2010, this seasonality was not shown but the general increasing
trend over that 2-year period is still exhibited. Although EPA agrees that using the definition of
BOD in calculating 30-day rolling averages will help to dampen emission spikes associated with
startup or shutdown events, significant variability still occurs, and steady increases in actual
emission rates are exhibited and may be associated with catalyst aging. Even when Dr. Fox
calculated 30-BOD rolling averages for Cardinal Unit 3, where the high value for the maximum
30-day calendar average resultedfrom one partial day of operation in April 2010, Cardinal Unit
3 would not have consistently met an emission limit of 0.05 Ib/MMBtu over 2009 - 2010. EPA
disagrees with commenters that 0.05 Ib/MMBtu achieved as a 30-calendar day average at
Havana Unit 9 and Parish Unit 8 is representative and appropriate to apply automatically as a
BART limit for any unit for which SCR was determined to be BART.
EPA examined the most recent CAMD emission rate data for 12 cell burner boilers
currently operating with SCR69 over 2009 - June 2011. Table 1 summarizes the N0X emission
rates (in Ib/MMBtu) and the percent reduction in N0X when the SCR was operatedfor the lowest
69 See tab titled "with SCR" in spreadsheet titled "Cellburners CAMD CAIR.xlsx" in docket for this final
rulemaking.
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achieved monthly calendar averages and the highest achieved monthly calendar averages to
show the range in variability within each year and compared across 2009 - 2011. EPA did not
exclude any monthly calendar averages from the minimum and maximum analyses shown in
Table 1. In order to determine what might be an appropriate % reduction to represent all cell
burner boilers currently using SCR, we calculate the average % reduction from the highest
emission rate achieved over all 12 units. As stated above, the 30-day rolling limit must be set to
accommodate the highest emission rate expected over the life of the catalyst. The percent
reduction achievedfrom the monthly calendar average emission rate over 2009 - June 2011
from the 12 units rangedfrom 48% to 90%, with an average value of 78%. The percent
reduction associated with the lowest emission rates achieved over 2009 - June 2011 are on par
with the percent reductions cited by commenters as the "common knowledge " capabilities of
SCR.
Table 1: N0X Emission Rates (lb MMHtu) and Percent N0X Reductions from Cell Burner Boilers
with SCR over January 2009 - June 2011
Facility
Unit
Lowest Emission Rate and Highest % Reduction
Highest Emission Rate and Lowest % Reduction
(State)
2009
2010
2011
2009
2010
2011
Rate
Reduc
Rate
Reduc
Rate
Reduc
Rate
Reduc
Rate
Reduc
Rate
Reduc
Alcoa
(IN)
4
0.088
79%
0.080
81%
0.085
80%
0.161
62%
0.173
59%
0.115
73%
Monroe
(MI)
3
0.048
90%
0.052
89%
0.065
86%
0.124
73%
0.146
69%
0.208
55%
Monroe
(MI)
4
0.058
88%
0.053
89%
0.070
85%
0.248
48%
0.134
72%
0.157
67%
Belews
(NC)
1
0.027
95%
0.040
93%
0.041
92%
0.078
85%
0.099
81%
0.094
82%
Belews
(NC)
2
0.024
94%
0.033
92%
0.032
92%
0.064
85%
0.061
86%
0.063
85%
Cardinal
(OH)
1
0.025
95%
0.033
94%
0.043
92%
0.085
83%
0.052
90%
0.065
87%
Cardinal
(OH)
2
0.021
96%
0.043
93%
0.051
91%
0.206
65%
0.074
87%
0.076
87%
Gavin
(OH)
1
0.065
91%
0.071
90%
0.072
90%
0.105
85%
0.122
83%
0.083
88%
Gavin
(OH)
2
0.063
93%
0.068
92%
0.071
92%
0.099
88%
0.102
88%
0.099
89%
Musk-
ingum
(OH)
5
0.049
92%
0.048
92%
0.051
91%
0.188
69%
0.149
75%
0.088
85%
Cumb-
erland
(TN)
1
0.060
91%
0.069
89%
0.060
91%
0.135
79%
0.129
80%
0.102
84%
Amos
(WV)
3
0.041
94%
0.045
94%
0.052
93%
0.185
74%
0.090
87%
0.107
85%
Commenters claim that emissions of sulfuric acid mist and the high ash content of coal
used by FCPP, and considerations of catalyst life are not barriers to achieving higher N0X
reduction efficiencies than proposed by EPA. EPA disagrees with comments that our statement
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regarding the impact of additional layers of catalyst on increasing sulfuric acid emissions is
unsupported. EPA understands from our correspondence with Hitachi Power Systems America
that each layer of catalyst used results in an incremental increase in the conversion rate of SO 2
to SO 3. The EPRI method usedfor calculating sulfuric acid requires the input of a SCR catalyst
oxidation rate. This oxidation rate varies depending on catalyst type and number of layers used.
For the ultra low SO2 to SO3 oxidation catalysts offered by Hitachi, each layer contributed
roughly 0.167% conversion, with 3 layers totaling 0.5%. The use of an additional layer, such as
in a 3+1 system, would thus increase the conversion rate to nearly 0.7% when all 4 catalyst
layers are in operation. Further N0X reductions achievedfrom the addition of a 5th layer of
catalyst would likely exacerbate pluggage and back-pressure concerns related to the ash content
of the coal and also may affect cost and operation of the unit. Commenters have not submitted
information to refute this.
The ash content of coal has an important effect on the effectiveness of SCR because high
ash content in coal can cause pluggage and catalyst erosion and thus reduce available catalyst
area and activity for N0X reduction. Based on coal quality information provided by the Energy
Information Administration within the U.S. Department of Energy's Office of Coal, Nuclear,
Electric and Alternate Fuels70, the coal ash content of coal burned at FCPP (20.34%)71 is
significantly higher (see Table 2) than the ash content of coals burned by the 77 72 cell burner
boiler units operating with SCR at 7 different facilities, as well as the Parish facility (Unit 5 is
reported in CAMD to be a wet-bottom wall-fired boiler) cited by commenters (0182) as being
one of the best performing units. EPA could not locate ash content of coal burned at the Havana
facility (Unit 9 is reported in CAMD to be a wet-bottom wall-fired boiler) in Illinois in the EIA
report. EPA notes that only four other facilities, in addition to FCPP, were reported in the EIA
to burn coal with ash content greater than 20%: San Juan Generating Station (SJGS) in New
Mexico, San Miguel in Texas, Nucla in Colorado, and North Branch in West Virginia. None of
those facilities currently have SCR installed on their boilers, however, Region 6 recently
finalized a FIP for SJGS with a limit of 0.05 Ib/MMBtu, representing an 83% reduction in N0X
emissions. The emission limit EPA Region 6 set for SJGS is lower than the limit we set for FCPP
because SJGS uses a different boiler type than FCPP and modern combustion controls have
already been installed and have reduced N0X emissions at SJGS by 29 - 33%.73 EPA has
determined that because Units 4 and 5 at FCPP are cell burner boilers, modern combustion
controls would not significantly reduce N0X emissions from FCPP. Even though the emission
limit differs, the reduction efficiency from the installation and operation of SCR at FCPP and
SJGS are generally consistent, particularly when considering the similarly high ash content of
coal (>20%) used at both facilities. In 2008, EPA Region 9 issued a pre-construction Prevention
of Significant Deterioration (PSD) permit to allow construction of a new coal-fired power plant
70 "Cost and Quality of Fuels for Electric Utility Plants 2001". Energy Information Administration, Office of Coal,
Nuclear, Electric, and Alternative Fuels, US Department of Energy, March 2004. DOE/EIA-0191(01), included in
the docket for this final rulemaking.
71 APS reports the ash content of coal burned at FCPP as approximately 25%, as stated in the TSD for our proposed
BART determination (EPA-R09-OAR-2010-0683-0002).
72 EPA could not locate information in the EIA report on the Alcoa Allowance Management Inc Facility in Indiana.
73 See page 4-3 of report titled "PNM BART Report for SJGS final to PNM June 18, 2007.pdf' in the docket for
this final rulemaking. Pre-consent decree emission rates on Units 1 - 4 at SJGS ranged from 0.42 - 0.45 lb/MMBtu.
Post-consent decree emission limits for those units were 0.30 lb/MMBtu.
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on the Navajo Nation, hi own as the Desert Rock Energy Facility (Desert Rock). '4 If constructed,
Desert Rock would have used the same coal as FCPP from the BHP Navajo Mine and the final
PSD permit set a N0X limit of 0.05 lb MMHtu (on a rolling 365-day average). Commenters argue
that if Desert Rock was required to meet a limit of 0.05 lb MMHtu using the same coal as FCPP,
the ash content should not hinder FCPP from achieving similarly low N0X emission rates. EPA
notes that if constructed, 5 Desert Rock would have been a new, state-of-the-art facility
specifically designed with boiler characteristics, combustion controls, and post-combustion
controls to meet the Best Available Control Technology (BACT) requirements for numerous
criteria and non-criteria pollutants. FCPP is an existing, over 40-year-old power plant. The
Regional Haze Ride requires a case-by-case BART (best available retrofit determination), which
need not be equivalent to BACT for new facilities.
Table 2: Ash Content of Coals Burned at Various Facilities using SCR
Facility Name
Owner76
State
Ash Content
Monroe
Detroit Edison
Michigan
6.3%
Belews Creek
Duke Power
North Carolina
12.23%
Cardinal
Cardinal Operating Company
Ohio
11.56%
Gavin
Ohio Power Company
Ohio
11.3%
Muskingum
Ohio Power Company
Ohio
11.54%
Cumberland
Tennessee Valley Authority
Tennessee
9.42%
Amos
Appalachian Power
West Virginia
11.93%
HL&P Parish
Reliant
Texas
5.28%
Based on the significant 30-calendar-day average variability exhibited by the top
performing units in Table 10 of comment number 0182, and the variability in 30-calendar-day
average and the 2009 - June 2011 30-calendar-day average % N0X reduction of 78% exhibited
by 12 cell burner boilers equipped with SCR, EPA continues to affirm that a limit representing
an 80% reduction in N0X emissions reflects what is achievable using the technology determined
as BART for FCPP.
Commenters further argue that many of the best-performing units operate without
permitted emission limits under an emission trading program and therefore have no incentive to
optimize SCR operation because they do not need to comply with an emission limit. EPA
disagrees with that statement and notes that units that operate under a regional N0X trading
program have a financial incentive to reduce emissions to the greatest economic extent possible
in order to sell those emission offsets to units that cannot meet the emission cap established by
the trading program.
74 http://www.epa.gov/region9/air/pemiit/desert-rock/
75 Desert Rock has not been constructed. EPA requested a voluntary remand of the Desert Rock PSD permit in 2009
to incorporate new applicable requirements. The developers of Desert Rock have not yet submitted a revised PSD
application to EPA.
76 As reported in the EIA Report (March 2004), included in the docket for this final rulemaking.
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Annual Averase Limit
In our Supplemental Proposal, EPA requested comment on setting a lower N0X limit over
a longer averaging time to account for catalyst degradation over time. In its comments, NFS
recommended an emission limit of 0.05 Ib/MMBtu or lower, on an annual average. NFS cited
three examples of cell burner boilers achieving annual average N0X emission rates less than
0.06 Ib/MMBtu and greater than 90% N0X removal: Cardinal Units 1 and 2, and Belews Creek
Unit 1. EPA agrees with NFS that over a 2-year average, N0X emissions from Cardinal Unit 1
averaged 0.036 Ib/MMBtu (2009 - 2010), however, as discussed above, these three units showed
a general increasing trend in N0X emission rates over time and the highest 30-day calendar
average in 2011 of 0.065 Ib/MMBtu was over 1.8 times greater than the 2-year average N0X
emission rate achieved by Cardinal Unit 1. For Cardinal Unit 2, the maximum 30-day calendar
average in 2011 was nearly 1.8 times higher than the 2-year average of0.043 Ib/MMBtu (2009 -
2010), andfor Belews Creek 1 the highest maximum 30-day average in 2010 of0.0989
Ib/MMBtu that was nearly 2.2 times higher than the 2-year average of0.045 Ib/MMBtu (2009 -
2010). The emission rate data from the three units cited by NFS suggest that 30-day average
emissions for these three units were roughly two times higher than the 2-year annual average
emission rates.
Data provided by Dr. Fox in Table 10 of comment number 0182 shows that 9 of the top
20performing units with SCR met an emission rate of 0.05 Ib/MMBtu or better over a 365-day
calendar average. The remaining units rangedfrom 0.055 - 0.069 Ib/MMBtu over a 365-day
calendar average. Based on our review of the most recently available CAMD data from 12 cell
burner boilers currently equipped with SCR, the % N0X reduction exhibited over a nearly 3 year
average (2009 - June 2011) ranges from 73 - 92%, with an average % N0X reduction of 87%.77
EPA agrees with commenters that N0X emission limits over a longer averaging time can be
lower than emission limits over a shorter averaging time. However, in its comment letter on the
Supplemental Proposal, APS stated that it opposed any further lowering of the N0X emission
limit for several reasons, including cost of compliance and potential operational problems.
Although not specifically stated by APS, EPA infers that APS's opposition to a lower limit
includes opposition to a lower limit over a longer averaging time. Additionally, APS stated that,
based on statistical analysis it has conducted, it believes there may be potential compliance
problems with the 30-day rolling average period, in particular, if two malfunction events
occurred close together towards the end of the catalyst replacement cycle. Therefore, APS stated
a 90-day rolling averaging would be needed to reasonably assure continuous compliance with
the proposed emission limit in the Supplemental Proposal. APS did not include its statistical
analysis in its comments on the Supplemental Proposal, and, for the reasons stated above and
supported by the emission rates and control efficiencies from other cell burner boilers with SCR
(Table 1), EPA has determined a 30 calendar-day rolling average is appropriate for the final
N0X limit for BART. Under the alternative emission control strategy we based the limit on 30-
BOD average. In addition, although EPA agrees with commenters that setting a lower emission
limit over a longer averaging time is supported by a review of emission data from other
facilities, we do not have enough information specific to Units 4 and 5 at FCPP to set a different
limit over a longer averaging time, nor is it necessary to supplement the short-term limit (30-day
77 See summary tab in "Cellburners CAMD CAIR.xlsx" spreadsheet in the docket for this rulemaking.
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rolling average) EPA is setting in our final action with an additional limit over a longer
averaging time.
Comment:
One of the owners of FCPP (0176/0177) stated a willingness to support aNOx emission
limit of 0.098 lb/MMBtu for Units 4 and 5 under the alternative proposal, but only in the context
of an alternative emission reduction strategy that includes resolution of the related issues. The
commenter asserted that issues with the cell-burner configuration of these units, the high-ash
coal that is burned, and the increase in H2SO4 emissions that would occur at increased NOx
efficiency preclude any further tightening of the NOx limit. The commenter recommended that
compliance with the emission limit be determined on a 90-day rolling average basis, instead of
the proposed 30-day rolling average. The commenter strongly opposed any plantwide NOx limit
more stringent than 0.11 lb/MMBtu in a traditional BART FIP.
The Navajo Nation (0223) similarly endorsed the proposed 80 percent reduction in NOx
emissions from Units 4 and 5, with a limit of 0.098 lb/MMBtu, under the supplemental proposal,
based on the site-specific parameters at FCPP. The commenter also cautioned that any reduction
in this standard must be evaluated carefully, because additional catalyst layers would be required
which could result in increased ammonia slip and H2SO4 emissions contributing to visibility
impairment, increased compliance costs, and operational difficulties. The commenter noted that
selection of the catalyst will be critical for the operation and performance of the SCR system.
Response:
EPA agrees that the appropriate limit for Units 4 and 5 under the alternative strategy is
0.098 lb/MMBtu (over a rolling average of 30 successive boiler operating days) for the reasons
aforementioned. The final rule reflects this limit.
Comment:
In virtually identical comments that addressed both FCPP and NGS submitted prior to the
supplemental proposal, one public interest advocacy group (0094) and one environmental
advocacy group (0146) requested that EPA implement the most stringent air pollution control
measures, specifically SCR, as BART for these plants in order to improve visibility in the Class I
areas to the greatest extent possible. The commenters noted that FCPP and NGS are two of the
biggest sources of NOx on the Colorado Plateau, and stated that they should not be allowed to be
permitted polluters and impair visibility throughout the region.
In later comments, the public interest advocacy group (0112) took the position that SCR
is BART for FCPP. The commenter opposes any attempt to substitute SNCR for SCR as BART,
which the commenter indicated the owner of SJGS is trying to do.
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One private citizen (0160) also urged EPA to require FCPP to install SCR controls at all
five of the plants units.
Response:
EPA agrees with these comments and the final BART rule and the BART alternative
require SCR at emission levels for NOx that will be achievable over the 3 year period between
scheduled maintenance for these EG Us.
Comment:
One environmental advocacy group (0182) asserted that EPA failed to consider data
sources critical to ensuring a thorough analysis and adequate NOx BART determination. To
support this assertion, the commenter drew heavily on an attachment containing comments
prepared by Dr. Phyllis Fox (0182). This comment summary includes the comments presented
by Commenter 0182; the reader may refer to the attachment (0182) for greater detail.
The commenter (0182) noted that EPA's BART Guidelines require permitting agencies
to "consider recent regulatory decisions and performance data (e.g., manufacturer's data,
engineering estimates and the experience of other sources) when identifying an emissions
performance level or levels to evaluate" (citing 40 CFR part 51, Appendix Y). The commenter
stated that there are numerous examples of SIP and permit limits set below the FCPP NOx limit:
• Texas SIP emission limits under a cap and trade program of 0.033 lb/MMBtu for the
Dallas/Fort Worth ozone nonattainment area and 0.050 lb/MMBtu for the
Houston/Galveston ozone nonattainment area for wall-fired boilers burning coal and
0.045 lb/MMBtu for tangential-fired boilers burning coal.
• Vendor guarantees that SCR at the limits of 0.03 lb NOx/MMBtu at Texas Parish's four
units is achievable, which were the basis for the Texas SIP limits above.
• The permit limits for Desert Rock, requiring the facility to achieve a NOx limit of
0.035 lb/MMBtu on a 365-day rolling average basis.
• Ten other similar facilities identified in Comment 0182 with permit or other instruments
establishing limits of 0.05 lb/MMBtu or better on a 30- or 365-day rolling average.
The commenter (0182) also stated that EPA should have evaluated performance data,
specifically the information available in the CAMD database that compiles CEMS data. The
commenter indicated that this information must be understood in the context of the regulatory
programs prompting its collection, which do not require the technology performs to its
reasonable capability. The commenter asserted that while this information in itself does not
establish a BART limit, evaluation of this information helps to determine a BART floor.
Response:
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EPA agrees with the commenter that the BART Guidelines state that agencies "should
consider recent regulatory decisions and performance data . . . when identifying an emissions
performance level or levels to evaluate However, the BART Guidelines further state that "[i]n
assessing the capability of the control alternative, latitude exists to consider special
circumstances pertinent to the specific source under review ", but the agency "should explain the
basis for choosing the alternate level (or range) of control in the BART analysis". See 70 FR at
39166, July 6, 2005. We discuss in the TSD for our proposed BART determination and in our
Supplemental Proposal for the alternative emission control strategy our rationale for proposing
a limit of 0.11 Ib/MMBtu on a plant-wide basis as BART and 0.098 Ib/MMBtu for Units 4 and 5
as part of the alternative emission control strategy, based on our determination that the
installation of combustion controls is not likely to result in significant N0X reductions without
potential operational challenges to the boilers because of inherent limitations associated with
the boiler design. Our final N0X limit for BART andfor Units 4 and 5 under the alternative
emission control strategy is discussed in further detail in this section of this RTC, in response to
the comment that the BART limit should be 0.05 Ib/MMBtu, or at least lower than 0.11
Ib/MMBtu. In that response, we also discuss emission levels reported to CAMD for several cell
burner boilers at different facilities. As reflected in presumptive N0X limits in the BART
Guidelines, different types of boilers are expected to achieve different levels ofNOx control.
Thus, comparing emission limits achieved by different boilers is not an "apples to apples "
comparison.
The commenter is correct in stating that compliance with the Texas SIP emission limits of
0.033 Ib/MMBtu for the Dallas/Fort Worth ozone nonattainment area and 0.050 Ib/MMBtu for
the Houston/Galveston ozone nonattainment area for wall-fired boilers burning coal and 0.045
Ib/MMBtu for tangential-fired boilers burning coal is achieved through a cap and trade
program. See Texas Administrative Code Chapter 117 requirements for combustion control at
major utility electric generation sources, e.g., Rules 117.1210 and 117.1220.78 This type of cap
and trade program offers much greater flexibility at meeting the standards (because units that do
not, by themselves, meet the emission standard can demonstrate compliance with the standard by
purchasing equivalent emission credits from units that perform better than the standard)
compared to an explicit permit limit for a single unit, which must be met by that specific unit
continuously for the life of the facility. Therefore, comparing the system cap emission limits set
in the Texas SIP and a plant-wide or unit specific emission limit under BART for units at FCPP,
which include cell burner boilers, is misleading.
Although the commenter notes that vendor guarantees of 0.03 Ib/MMBtu for the Parish
units were demonstrated on Parish Unit 8 in August - November 2006, where Unit 8 was run at
0.03 Ib/MMBtu, then at 0.035 Ib/MMBtu, EPA notes, and the commenter acknowledges, that the
Parish units do not normally and consistently achieve the vendor guarantee of 0.03 Ib/MMBtu.
Parish Unit 8 typically achieves 0.044 Ib/MMBtu, and other coal-fired units at Parish typically
achieve closer to or above 0.05 Ib/MMBtu. EPA further notes that the coal-fired units at Parish
(units 5 - 8), equipped with advanced LNB+OFA systems, e.g., based on CAMD data from 2001
and 2002 79, typically achieved 0.14-0.18 Ib/MMbtu. Following installation with SCR, a vendor
guarantee of 0.03 Ib/MMBtu represents a 79-83% reduction in N0X emissions. Based on more
78 See http://info.sos.state.tx.us/pls/pub/readtac$ext.ViewTAC?tac_view=5&ti=30&pt=l&ch=117&sch=C
79 See "WA Parish CAMD monthly 2001-2010.xlsx" in the docket for this final rulemaking.
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typical emission rates of around 0.05 Ib/MMBtu from the Parish Units 5-8, the percent N0X
reduction ranges from approximately 64 - 72%. Thus, our final N0X limit for FCPP based on an
80% reduction from SCR alone is comparable to the vendor guaranteed N0X reductions for
Parish and exceeds the N0X reductions typically achieved at the Parish facility.
The commenter further cites the BACT determination and limit for N0X in the final PSD
permit issued by EPA Region 9 to the Desert Rock Energy Facility (DREF) as a lower limit than
the one proposed andfinalized as BARTfor FCPP. If constructed, DREF would have used coal
from the same mine as FCPP, thus commenter s generally argue that emission limits set for
DREF should be achievable at FCPP as well. EPA notes that DREF was permitted as a new,
greenfield facility using the most advanced boiler design and air pollution control equipment to
meet the BACT requirements under the PSD program. EPA Region 9 requested a voluntary
remand of the DREF permit to address issues related to other pollutants (greenhouse gases and
PM2.5), therefore the final permit issued by Region 9 to DREF is not valid, and DREF has not,
and cannot, commence construction. Thus, the N0X emission limits set for DREF, in particular,
the 365-day rolling average limit of 0.035 Ib/MMBtu, have not been achieved or demonstrated in
practice on the high ash coal from the Navajo Mine. Furthermore, EPA disagrees that the
emission limits set as BART necessarily must reflect limits set as BACT.
As stated in responses to other comments in this section, EPA disagrees with the
assertion that emission limits associated with BART must meet the lowest emission rate achieved
at any coal-fired power plant. The Regional Haze Regulations at 40 CFR §51.308(e)(l)(ii)(A)
state that:
The determination of BART must be based on an analysis of the best system of
continuous emission control technology available and associated emission
reductions achievable for each BART-eligible source that is subject to BART. . .
Additionally, the BART Guidelines state that: "To complete the BART process, you must
establish enforceable emission limits that reflect the BART requirements . . See 70 FR 39172,
July 6, 2005. The five-factor BART analysis described in the Guidelines is a case-by-case
analysis that considers site specific factors in assessing the best technology for continuous
emission controls. After a technology is determined as BART, the BART Guidelines require
establishment of an emission limit that reflects the BART requirements, but does not specify that
the emission limit must represent the maximum level of control achieved by the technology
selected as BART. The BART Guidelines and the RHR do not preclude selection of the maximum
level of control achieved by a given technology as BART, however, the emission limit set to
reflect BART must be achievable by the specific source and should be determined based on
consideration of site-specific factors. Therefore, limits set as BACT during PSD review (e.g.,
Desert Rock), or emission rates achievedfrom the operation of individual facilities under an
emissions trading program (e.g., Texas SIP) may provide important information, but should not
be construed to automatically represent a ceiling for BART limits representative of a given
technology.
Comment:
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One of the owners of FCPP (0176/0177) opposed EPA's proposal to "phase in" NOx
controls at FCPP under a traditional BART FIP, commencing 3 years from the date the FIP
becomes effective. The commenter asserted that this proposal does not afford adequate time to
properly design, engineer, and construct the controls before the compliance deadline because the
proposal would give APS only 2 years after the approval or disapproval of the proposed
transaction with Southern California Edison to achieve full compliance with the new emission
limit. The commenter argued this schedule would be very nearly impossible to meet because of
the scale and complications involved in this large and expensive engineering project. See related
comments in Section 6.0. Another FCPP owner (0168) expressed support for
Commenter 0176/0177 on this issue. This commenter stated that the proposed phase-in is
burdensome and unnecessary, and that the FCPP owners should be afforded the flexibility to
schedule construction of BART controls within 5 years as is typically allowed.
Response:
EPA revised the BART compliance date for one 750 MW unit (either Unit 4 or 5) to
within 4 years from the effective date of this final rule, and the remaining 750 MW unit and Units
1-3 to within 5 years of the effective date of the final rule. The revised compliance time within 4
and 5 years allows time for design, engineer, and construct controls.
Comment:
One environmental advocacy group (0182) stated that the proposed plantwide BART
limit of 0.11 lb/MMBtu across all five FCPP units violates Executive Order 12898 on
environmental justice. Specifically, the commenter stated that given the significant differences in
pollution control systems among FCPP's five units, allowing a plant-wide average could create
pollution "hotspots" with respect to co-pollutants. As an example, the commenter noted that
while Units 4 and 5 have baghouses, Units 1-3 use less efficient venturi scrubbers for control of
sulfur dioxide, particulate matter, and mercury. The commenter asserted that the plantwide
average limit for NOx would allow increased emissions from Units 1 - 3 in the event of a
temporary outage or reduced output from one or both of the larger units. The commenter stressed
that while this may not increase the total NOx emissions from the plant, it would increase the
amount of mercury and other toxic co-pollutants emitted into the surrounding community, which
is a low-income community of color.
The commenter (0182) stated that this is precisely the type of scenario Executive
Order 12898 seeks to avoid. The commenter indicated that EPA should impose unit-specific
BART limits, which it unquestionably has the authority to do (citing 40 CFR part 51,
Appendix Y). In the alternative, the commenter urged EPA to conduct a full environmental
justice analysis, supported by modeling, to show that its plantwide average will not cause
disproportionate environmental harm in the surrounding community under any operating
scenario.
Response:
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EPA disagrees with the commenter that a plant-wide BART limit of 0.11 Ib/MMBtu
across all five FCPP units violates Executive Order 12898 on environmental justice. EPA 's final
action establishing this plant-wide emission limit for N0X represents an 80% reduction in overall
N0X emissions over the current baseline emissions for this single facility. This final rule is not
expected to have disproportionately high and adverse human health or environmental effects on
minority or low-income population because it increases the level of environmental protection for
all affected populations in the area including any minority or low-income population.
The commenter is correct that in the event of a temporary outage or reduced output from
unit 4 or 5 the operator could continue to operate FCPP units 1-3 under the original BART
proposal provided that they maintain compliance with the plant-wide emission limit of 0.11
Ib/MMBtu for N0X. In order to maintain compliance with the plant-wide emission limit, units 1-3
would have to operate at a lesser capacity than they would normally operate if unit 4 and 5 were
functioning because units 1-3 emit higher amounts of N0X than units 4 and 5. The N0X emission
rates from Units 1-3 with SCR, based on 80 percent control of current emission rates would be
0.16, 0.13, and 0.12 Ib/MMBtu respectively which are higher than the proposed plant-wide
emission limit.80 Therefore, to maintain compliance with the plant-wide N0X emission limit
(which is based upon a 30 calendar-day rolling average), units 1-3 would have to operate at a
reduced capacity and could only operate if unit 4 or 5 were also concurrently operating. This
reduced capacity would result in an overall lower rate of emission for mercury and other co-
pollutants from units 1-3. Therefore, there would be no increased emissions of mercury or other
co-pollutants and no "hot-spots " or disproportionately high and adverse human health or
environmental effects on minority or low-income population.
The BART Guidelines at 40 CFR Part 51, Appendix Y, Section 4 state that average
emissions across any set of BART-eligible emission units within a fenceline should be considered
provided that the emission reductions from the pollutant be equal to those reductions that would
be obtained by simply controlling each of the BART-eligible units at that source. EPA proposed
and is finalizing a plant-wide heat input-weighted average emission limit of 0.11 Ib/MMBtu.
This BART determination can be met by achieving 80% control on Units 1 - 5 by the application
of SCR. EPA further notes that the commenter's concern about increased usage of the less
efficient Units 13 would not occur if APS implemented the alternative emission control
strategy involving closure of Units 13.
Comment:
One of the owners of FCPP (0174) and one utility industry association (0169.1) consider
the BART proposal to be inconsistent with President Obama's January 18, 2011 Executive Order
13563 pertaining to regulatory strategy. One of the commenters (0174) alleged that EPA failed to
properly consider the two key principles of the Executive Order:
80 See page 87 of the TSD for the proposed rule; Document No. EPA-R09-OAR-2010-0683-0002.
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• Consistent with law, Agencies must consider costs and benefits and choose the least
burdensome option.
• Agencies must consider low-cost approaches that reduce burdens and maintain flexibility.
Regulations must be guided by objective scientific evidence.
The commenters (0169.1, 0174) asserted that SCR represents a very high cost, low
benefit option. In addition, they stated that modeling that relies on CALPUFF version 5.8 and the
IWAQM default background ammonia values does not represent the best available science.
Response:
EPA disagrees that our BART determination is inconsistent with President Obama's
Executive Order 13563 or that SCR is a high-cost, low-benefit option.
Executive Order 13563 is supplemental to and reaffirms the principles, structures, and
definitions governing contemporary regulatory review that were established in Executive Order
12866 of September 30, 1993. Our proposed andfinal actions are not "significant regulatory
actions" under the terms of Executive Order 12866 (58 FR 51735, October 4, 1993) because
these rules only apply to one facility and are not rules of general applicability.
The President issued Executive Order 13563 on January 18, 2011, after we issued our
Proposed Rule but just prior to our Supplemental Proposal. In general, the Order seeks to
ensure the regulatory process is based on the best available science; allows for public
participation and an open exchange of ideas; promotes predictability and reduces uncertainty;
identifies and uses the best, most innovative, and least burdensome tools for achieving
regulatory ends; and takes into account benefits and costs, both quantitative and qualitative.
EPA conducted our BART determination for FCPP using the site-specific five-factor
analysis in the BART Guidelines. As part of that analysis, EPA carefully considered the cost of
controls and the benefits of those controls to improve visibility in the surrounding Class I Areas
to achieve the goals stated in the CAA and RHR. As described below in more detail, based on the
results from the original analysis for the proposed BART determination, EPA concluded that the
installation and operation of SCR on all five units at FCPP would not adversely affect the
competitiveness of FCPP's cost to generate electricity compared to the cost to purchase
electricity on the open market. EPA notes that our BART determination for FCPP does not
specifically require SCR technology, rather, we have set an emission limit for NOx that can be
achievedfrom the installation of SCR. The facility has the flexibility to determine the least-
costly, least burdensome way of meeting that emission limit. EPA provides additional flexibility
by giving the owners of FCPP the option to implement the alternative emission control strategy
in lieu of BART, an alternative that was largely proposed by APS on behalf ofFCPP's owners.
As discussed more fully in Section 3.1 of this RTC, EPA disagrees that SCR represents a
high cost, low benefit option.
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EPA's use of CALPUFF version 5.8 for modeling of visibility benefits and the IWAQM
default background ammonia values represent the best available science as discussed above in
responses to comments in Section 7.0 of this RTC.
Comment:
One of the owners of FCPP (0174) stated that in establishing BART for FCPP, EPA did
not consider the progress already made towards improving visibility on the Colorado Plateau.
The commenter asserted that instead of taking this progress into consideration as support for
establishing a cost-effective control option as BART in this first planning period, EPA imposed
the most stringent and costly controls as BART and attempted to justify this proposal by raising
uncertainties with respect to the contribution of nitrates to regional haze in the Colorado Plateau.
The commenter argued that if EPA takes into consideration the available data showing the
progress already made towards improving visibility on the Colorado Plateau, and the extensive
work performed by the Western Regional Air Partnership that shows the small contribution of
nitrates to regional haze, EPA will be compelled to conclude that reasonable progress can be
made in the first planning period by requiring the installation of cost-effective LNB as BART for
FCPP, and additional controls can be required, if necessary, in future planning periods.
The Navajo Nation (0223) acknowledged and supported the intent of the reasonable
progress goals under the CAA [quoting 40 CFR 51.308(d)(l)(i)(B), which discusses calculating
and using the necessary uniform rate of progress to set the reasonable progress goal], but stated
that in its visibility analysis, EPA should consider the cumulative benefits in visibility
improvements from all neighboring states' regional haze SIPs and BART determinations. The
commenter also indicated that real-time data should be used whenever possible as it becomes
available.
Response:
EPA disagrees with the commenter that we must consider progress already made toward
improving visibility on the Colorado Plateau or that reasonable progress can be made by the
installation of LNB as BART at FCPP. EPA further disagrees that any reasonable progress
already made towards improving visibility would invalidate the BART provisions of the RHR, as
the commenter seems to imply. The FCPP is one of the largest stationary sources of NOx in the
country, and is located near many Class I areas where visibility is highly valued, so it is highly
appropriate to undertake a BART analysis for it. In any case, a BART analysis for FCPP is
required under the RHR.
EPA does agree with certain aspects of the comments regarding a phased implementation
strategy to attaining national visibility goals. In 40 CFR 51.308(f), States are required to revise
their regional haze implementation plans every ten years, which is a process that involves
evaluating their ability to attain reasonable progress goals and potentially updating their long-
term strategy for regional haze. The periodic revision requirement described in 40 CFR
51.308(f), however, does not extend to the implementation plan for BART requirements. The
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phased approach described by the commenter has certain benefits, and a phased approach is
incorporated into the alternative emission control strategy.
Any downward trends in SO 2 and N0X emissions or improvement in visibility on the
Colorado Plateau are due to variability in natural emissions on a short term basis, or else to
reductions of anthropogenic emissions, which occur partly in response to regulatory
requirements like BART. Application of BART is one means by which downward emission and
impairment trends may continue.
Contrary to what the commenters seem to imply, seemingly small relative contributions
to visibility impairment do not exempt sources from BART. Estimates of visibility impairment
vary by the estimation method used. Reliance on an average over groups of days and on the
percentage of the overall inventory may not be the best methodfor attributing impairment to
particular sources; under the BART Guidelines, individual source impacts are estimated using
CALPUFF modeling. Estimates of impairment from stationary source N0X also vary by location,
calendar year, and time of year. For many Class I areas in the western U.S., the worst visibility
occurs during summer, when carbon from fires is a dominant impairment component; this makes
stationary source N0X appear small in a relative sense. Nevertheless, stationary source N0X
remains an important component of visibility impairment, one that cannot be neglected. Any one
segment of the overall emission inventory might be dismissed as too small to apply controls to, in
which case no progress could be made toward the RHR national goal of remedying visibility
impairment from manmade pollution. Instead, the RHR identifies stationary sources as an
important category for evaluation, in the form of a BART analysis. Modeling has shown that
many individual stationary sources have the potential to contribute to visibility impairment (i.e.,
have a modeled impact of at least 0.5 dv, 70 FR 39161). In particular, EPA modeling of FCPP
as discussed in the TSD for our proposed rulemaking showed visibility impacts from 1.2 to 6.0
deciviews, depending on the Class I area (or from 0.8 to 3.2 deciviews if lower ammonia
background is assumed as recommended by some commenters). These are not negligible
impacts.
EPA also disagrees with the commenter that we should consider the cumulative benefits
in visibility improvements from all neighboring states' regional haze SIPs and other BART
determinations in determining BART for FCPP. The BART analysis is conducted on a source-
specific basis. Nothing in the BART regulations or guidance requires that EPA consider visibility
improvements from other sources in determining BARTfor a particular source under the RHR.
The Navajo Nation EPA has not developed a TIP for Regional Haze, nor does the Navajo
Nation have within its jurisdiction any federal mandatory Class I areas as set by Congress81. As
explained in the preamble to our proposed BART rule, FCPP and NGS are the only BART-
eligible sources located on the Navajo Nation. FCPP contributes to impairment at many
surrounding Class I areas.
81 EPA notes that Navajo Nation has established its own parks and monuments, including Monument Valley,
Canyon de Chelly, and the Four Corners Monument, however, these parks are not mandatory Class I Federal Areas
as set by Congress.
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EPA is exercising its discretion to promulgate emission limitations for FCPP to close the
regulatory gap with respect to this facility. In light of the magnitude of emissions of NO x from
FCPP, EPA is proposing to find that it is necessary or appropriate to establish BART
requirements for NOxfrom FCPP, and is proposing specific N0X limits as BART.
EPA agrees with the commenter that real-time data should be used whenever possible as
it becomes available.
8.2 Comments on the Proposed BART Determination for PM
Comment:
One of the owners of FCPP (0176/0177) asserted that the existing controls at FCPP
constitute BART for PM emissions. The commenter contended that the impact of PM controls on
the visibility in the neighboring Class I areas would be "vanishingly small" while the cost would
be "exorbitant" (resulting in cost effectiveness ranging from $51,500 - $148,659 per ton reduced
and from $1.4 billion - $3.7 billion per dv improvement). The commenter pointed out that
Table 4 in the proposal preamble, where EPA's modeling of the proposed BART emission levels
is summarized, shows visibility improvements of 0.02 dv at three Class I areas, 0.01 dv at seven
areas, and 0.00 at the remaining areas. Given that the EPA's own definition requires at least
0.5 dv to "contribute" to visibility impairment, the commenter argued that EPA has not presented
a basis to require FCPP to retrofit any additional PM controls at the plant, particularly not at an
estimated capital cost of over $215 million. Another of the FCPP owners (0179) and the Navajo
Nation (0223) made similar points, but in relation only to Units 1 - 3. A third FCPP owner
(0174) similarly noted that the impact of PM reductions estimated by EPA would have almost no
effect on visibility, concluding that no additional controls should be required as BART for FCPP.
The Navajo Nation (0223) stated that EPA acknowledged the high incremental cost of
new PM controls on Units 1-3 (citing 75 FR 64230), yet justified the cost effectiveness of
baghouses by comparison with similar retrofit projects in EPA Region 9. This commenter argued
that EPA failed to properly evaluate the costs associated with installation of bag houses using
site-specific parameters, thereby deviating from the BART Guidelines. The commenter also
stated that future CAA rulemakings, such as MACT regulations, will provide EPA an
opportunity to evaluate the feasibility of control technology during periodic reviews of the EPA
air quality standards. The commenter asserted that continued operation of venturi scrubbers to
meet emission limits of 0.03 lb/MMBtu and an opacity limit of 20 percent satisfies BART for
Units 1 - 3.
The Navajo Nation (0223) expressed support for the supplemental proposal to require a
PM emission limit of 0.015 lb/MMBtu and 10 percent opacity limit on Units 4 and 5. The
commenter presumed that FCPP can readily meet these standards prior to installation of SCR
since the limits can be achieved with the existing bag houses.
Regarding the EPA's proposed 10 percent opacity standard for each unit, two of the
owners of FCPP (0168, 0176/0177) stated that the EPA has not specified any costs or predicted
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any improvement in visibility that would result from such limits. The commenters asserted that
without such basis, the EPA cannot justify the proposed opacity limits. The commenters
concluded that the EPA should withdraw its proposed determination that baghouses are BART
for Units 1-3 and its proposal to make the opacity standard for Units 4 and 5 more stringent.
Response:
As stated in our proposed BART determination for PM, the existing venturi scrubbers on
Units 1 - 3 at FCPP do not constitute BART. In our proposed BART determination for FCPP,
EPA proposed a PM emission limit for Units 13 that can be achieved through the installation
of any offour different PM control options. A t the time of our BART proposal, the MA TS Rule for
electric utility steam generating units had not yet been proposed, nor had APS suggested its
alternative emission control strategy to close Units 1 3 in lieu of complying with BARTfor
NOx. Because the final MATS rule has been issued See 77 FR 9304, February 16, 2012 and sets
filterable PM and mercury limits that would be applicable to the units at FCPP, and because
EPA is finalizing this rule to allow APS to either comply with the alternative emission control
strategy or BARTfor NOx, EPA is determining that it is not necessary or appropriate at this time
to finalize our proposal to set new PM limits for Units 13.
Regarding our proposed BART determination for PMfor Units 4 and 5, we are finalizing
the proposed 0.015 Ib/MMBtu emission limit based upon the proper operation of the existing
baghouses. However, we have determined based on the comments we receivedfrom the operator
of FCPP that it is not necessary or appropriate to take final action on the proposed 10 percent
opacity limit. We have determined that imposing a 10 percent opacity limit will not provide
greater assurance that Units 4 and 5 at FCPP are meeting the PM emission limit of 0.015
Ib/MMBtu. We have determined previously that a 20 percent opacity limit is sufficient to ensure
the PM emission limit is being continuously met. The 10 percent opacity limit was generally
supported by the Navajo Nation and environmental groups. EPA has promulgated some recent
rules for electric generating units that have retained a 20 percent opacity standard rather than
reducing that limit to 10 percent. Specifically, EPA 's revised the New Source Performance
Standardfor large electric generating units at 40 CFR Part 60, Subpart Da, to lower the PM
emission limit for new units to 0.09 Ib/MMBtu for gross energy output or 0.097 Ib/MMBtu for net
energy output. For existing units that reconstruct or modify, Subpart Da establishes an
emissions limit of 0.015 Ib/MMBtu. For both standards, EPA retained a 20 percent opacity
standard as being sufficient to ensure compliance with either the 0.090 (0.097) Ib/MMBtu or
0.015 lb/ MMBtu PM emission limit. EPA 's MA TS rule, which was finalizedjust a few months
ago, also retained a 20 percent opacity standard as being sufficient to ensure compliance with
the PM emission limit that will be required for electric generating units subject to that rule.
The importance of the opacity limit is that a certain percentage opacity is an
instantaneous demonstration that a unit is in compliance with its PM emission limit. If a unit
does not install and operate a PM continuous emissions monitor, then EPA ensures compliance
with the PM emission limit by requiring an episodic source test. For the periods between
episodic source testing, EPA can ensure continuous compliance with the PM emission limit by
observing that the unit's stack emissions do not exceed a set opacity. EPA 's recent rulemakings
have determined that 20 percent opacity is sufficient to ensure compliance with a PM emission
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limit lower than the emission limit we have determined is BARTfor Units 4 and 5. Accordingly,
EPA is determining the 20percent opacity limit that we promulgated in our 2007 FIP for FCPP
as being adequate to ensure continuous compliance with the PMBART limit or 0.015 lb/
MMBtu.
Comment:
One group of environmental advocacy groups (0182) supported setting a 10 percent
opacity limit for Units 1 - 5, as measured by continuous opacity monitors (COMS), for the
reasons stated in the proposal preamble. However, based on information in a report prepared by
Vicki Stamper and submitted by the commenter (docket number 0182.3), the commenter (0182)
argued that the particulate matter BART limits for FCPP Units 1-3 should be based on the
installation of fabric filter baghouses, as this control is likely the only PM control that will ensure
the FCPP units can meet the forthcoming mercury MACT limit of 1 lb/TBtu and the related PM
limit. The commenter added that baghouses will also likely result in the lowest filterable PM
emission rates and will also greatly reduce fine particulate.
The commenter (0182) added that based on prior PMio BACT determinations with
baghouses, a BART limit on filterable PMi0 should be no higher than 0.010 lb/MMBtu, along
with an opacity limit no higher than 10 percent as EPA required as BACT at the Desert Rock
facility. The commenter agreed that an opacity limit is necessary to show continuous compliance
with the particulate matter BART limits (citing 75 FR. 64223).
In addition, the commenter (0182) indicated that EPA has proposed a BART limit only
for PM, which appears to be only filterable particulate matter. The commenter stated that the
BART guidelines specify that BART should be evaluated and defined for both PMio and PM2.5
(citing 40 CFR part 51, Appendix Y, section IV. A) and, consequently, that EPA must evaluate
and define BART limits for both PMio and PM2.5 The commenter also asserted that as part of the
PM2.5 BART determination, EPA must impose emission limits on condensable particulate
matter, which is typically in the size range of 2.5 micrometers or smaller. Thus, the commenter
asserted that in addition to a filterable PM BART limit, EPA should impose a BART limit on
total PM2.5.
One public interest advocacy group (0112) supported EPA's proposal and supplemental
proposal to require a PM limit and a 10 percent opacity limits on Units 4 and 5. The commenter
indicated that these limits should become effective prior to SCR installation, regardless of
whether the BART or alternative emission control plan is implemented. A private citizen (0192)
also stated that PM and opacity limits on Units 4 and 5 should become effective at the earliest
practicable date, seeing no reason why their effective date should be tied to SCR installation.
In "preliminary" comments submitted prior to the supplemental proposal, a similar group
of environmental advocacy groups (0095) suggested PM limits of 0.012 lb/MMBtu on a 6-hour
block average, applicable to each individual unit at FCPP. The commenter suggested that
compliance be required by 2014, determined using CEMS. The commenter also supported EPA's
proposal of an opacity limit of 10 percent, to be measured using COMS. The commenter added
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that the BART determination should include a provision that FCPP may forego BART
implementation at any unit if it agrees to retire that unit prior to the deadline for BART
implementation. The commenter requested that these limits be published for comment in any
Federal Register notice published to take comment on the FCPP alternative BART proposal.
Response:
EPA proposed a BART limit of 0.012 Ib/MMbtu for Units 1-3. There are various control
technologies that can achieve this limit including a baghouse, as mentioned by the commenter.
The least expensive approach would be to install a wet membrane ESP after the venturi
scrubber. BART is an emission limit and EPA does not dictate the control technology that must
be installed to meet it. As mentioned in the previous response, EPA is determining that it is not
necessary or appropriate at this time to take final action on the proposed PM BART limit for
Units 1-3. Nonetheless, as stated in the TSD for our proposal, EPA does not believe the existing
venturi scrubbers constitute BART.
EPA agrees with the commenter that the PM and Hg emission limits in the MATS Rule82
may require installation of baghouses on Units 1-3 to meet the standards. EPA is not finalizing a
PM BART determination at this time for those 3 units because these units will either be closed,
consistent with the alternative emission control strategy, or will be subject to the MATS Rule,
which will set additional emission limits. Because EPA is not finalizing a PM standard at this
time for Units 1-3, it is not timely to address the commenters' recommendation on an opacity
limit for these units or the tighter limit of 0.01 Ib/MMbtu.
EPA is finalizing the proposed PM BART limit for Units 4 and 5 of 0.015 Ib/MMbtu
which can be met with the proper operation of the existing baghouses. Because these baghouses
are more than 25 years old, it is not appropriate to impose a more stringent PM limit such as
one that has been set or proposedfor a newly constructedEGU.
EPA disagrees with the commenters' recommendation that the condensable fraction must
be included in the PM BART limits. EPA has previously outlined our reasoning as to why an
H2SO4 limit is not appropriate at this time (it will be addressed through the pre-construction
permitting process if needed) and EPA expects that H2SO4 will be the main component of
condensable PMfrom a coal fired EGU with an SCR. The existing 20% opacity limit is sufficient
to provide reasonable assurance of the unit's compliance with the PM BART limit.
As mentioned in a previous response, EPA is not finalizing the proposed 10% opacity
limit. While the 10% opacity limit was generally supported by the Navajo Nation and
environmental groups, upon further consideration of opacity limits set in other national EPA
rulemakings, including the final MATS rule and NSPS Subpart Da, EPA is maintaining the 20%
opacity limit that is already in the 2007FCPP FIP.
EPA agrees with commenters that PM limits on Units 4 and 5 should become effective
prior to SCR installation, as Units 4 and 5 generally already meet the 0.015 Ib/MMBtu limit.
82 See 77 FR 9304, Februaiy 16, 2012
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EPA is finalizing a compliance date for PM emission limits on Units 4 and 5 to be within 6
months after restart following the next scheduled major outages in 2013 and 2014.
EPA disagrees with the commenter that a CEMs (presumably a PM CEMs) be used to
determine the continued compliance with the PM limits for Units 4 and 5. As stated previously,
the existing 20% opacity limit is sufficient to provide reasonable assurance of the unit's
compliance with the PM BART limit.
Comment:
One commenter (0182.3) submitted a technical review of the PM BART determination,
which was attached to the comments of an environmental advocacy group (0182), as noted
above. A brief summary of the major points of this review related to Units 1-3 follows:
• Venturi scrubbers are not the best system of continuous emission reduction.
• The costs of installation new particulate controls, particularly baghouses, at FCPP
Units 1 - 3 are reasonable.
- Costs of PM controls are overestimated.
- Effectiveness of PM controls is underestimated.
- APS's cost effectiveness analysis of PM controls only reflects incremental costs.
- Revised analyses show that the installation of a baghouse is cost effective - average
cost effectiveness ranging from $40.04/ton to $52.56/ton.
• The energy and environmental impacts analyses weigh strongly in favor of installation of
baghouses at FCPP Units 1-3.
- A baghouse will likely be necessary to meet mercury MACT limits.
- New PM controls will be needed to meet the EPA's proposed PM limit for non-
mercury metal HAPs.
- The greater reduction in mercury emissions that a baghouse would allow for could
help address mercury deposition levels in the region.
- The secondary plume from FCPP Units 1-3 causes localized visibility impairment.
• Upgraded PM controls at FCPP Units 1-3 will improve visibility at nearby Class I areas.
• The BART limits for Units 1-3 should be based on the installation of baghouses with a
limit on filterable PMio no higher than 0.010 lb/MMBtu, along with a 6-minute average
opacity limit no higher than 10 percent. The EPA must also define BART limits for PM2.5
and condensable PM.
The commenter's (0182.3) major points related to PM BART for Units 4 and 5 are as
follows:
• Units 4 and 5 can meet lower particulate matter BART limits than proposed by EPA.
• The EPA should evaluate the PM and SO2 reductions that can be obtained with the
elimination of bypasses of the scrubber.
• The EPA must evaluate and impose BART limits for PM10 and PM25.
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• The filterable PM emission limits should be no higher than 0.012 lb/MMBtu, which the
units are actually achieving. The EPA should evaluate options for achieving filterable PM
emission limits of 0.010 lb/MMBtu as has been required to meet BACT requirements in
several recent PSD permits. The proposed 10 percent opacity limit measured with COMS
is necessary to show continuous compliance with the PM BART limits.
Response:
As previously mentioned, EPA is not finalizing the PM BART determination for Units 1-3
at this time.
With regards to units 4 and 5 PM BART, EPA does not agree that the limit needs to be set
at what can be achieved by new EGUs considering these baghouses are more than 25 years old.
EPA also disagrees with the needfor a PMw, PM2.5 or a condensable limit for these units. There
is very little data available at this time for setting any of these limits. A PM limit is an adequate
surrogate for these smaller fractions. A leak in a baghouse will pass all size fractions of PM and
setting the limit with a Method 5 front half measurement is adequate for all size fractions for a
baghouse-controlled coal fired EGU. As mentioned previously and elaborated on more in RTC
in section 8.4, EPA does not agree that a condensable limit is neededfor BART.
8.3 Comments on BART for S02
Comment:
Some commenters (0095, 0112, 0140, 0182) asserted that S02 BART should be required
for FCPP, while one commenter (0224) simply noted that FCPP is subject to BART for SO2.
Their comments are summarized in the paragraphs that follow.
One federal agency commenter (0224) stated that FCPP is subject to BART for S02. The
commenter stated that Units 4 and 5 should be able to meet a limit of 0.12 lb/MMBtu on an
annual average basis by upgrading the existing scrubbers.
One group of environmental advocacy groups (0182) discussed the Regional Haze rules,
the TAR, and the SO2 emissions from FCPP and concluded that EPA is under a legal obligation
to conduct a BART analysis for S02 emissions from FCPP and, to the extent EPA has failed to
make a finding that it is "necessary or appropriate" to regulate SO2 emissions from the FCPP,
such a failure is arbitrary, capricious, and not supported by the administrative record. The
commenter added that EPA's proposed FIP is also arbitrary and capricious because it fails to
conduct any BART analysis for S02 emissions from the FCPP, and because EPA fails to comply
with its methodology for conducting BART determinations found in the Regional Haze rules at
40 CFR 51.308(e) and the BART Guidelines.
According to the commenter (0182), EPA argues that FCPP's current S02 emissions
limits are "close to or equivalent" to the limit that would be established under BART. The
commenter argued that this conclusion is likewise arbitrary and capricious because EPA has
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failed to undertake any scientific or technical analysis to support its conclusion - rather than
conduct such an analysis, EPA simply stated that the FCPP agreed to reduce S02 emissions
pursuant to a prior voluntary compliance agreement. However, the commenter notes that a
review of the administrative record shows that EPA did not conduct an S02 BART determination
for the FCPP at that time, and has not conducted such an analysis since that time.
The commenter (0182) goes on to assert that under the plain language of the Regional
Haze rules at 40 CFR 51.308 and the BART Guidelines, EPA must make now make an S02
BART determination for the FCPP as part of this source-specific regional haze FIP. Moreover,
the commenter argued that an S02 BART determination is likewise important to meet the
requirements of section 110 of the CAA as it relates to interstate transport of visibility impairing
emissions. The commenter contended that EPA's failure to make an S02 BART determination
for FCPP under the methodology prescribed by its own regulations and guidelines is arbitrary
and capricious and must be corrected in the final rule.
The commenter (0182) made the following points about an S02 BART analysis at FCPP:
• The fact that the FCPP reduced SO? earlier than BART deadlines should not influence a
proper BART determination. The commenter asserted that given the complicated
regulatory history of S02 controls at FCPP and the fact that S02 controls were required
since the mid 1970's but were not installed until the early 1980's, APS should not be
given credit to avoid a complete S02 BART analysis because the company finally took
actions to achieve better S02 control. The commenter also stated that an analysis of the
new 1-hour average S02 NAAQS standard could show that FCPP's current controls are
necessary to ensure the FCPP does not cause or contribute to violations of the 1-hour
average S02 NAAQS, and thus are not early controls. Finally, the commenter stated that
given that EPA imposed enforceable S02 emission limits in 2007, the same year regional
haze SIPs were due to be submitted to EPA and given that the methods planned on to
reduce S02 at FCPP could be implemented fairly readily (i.e., there was no installation of
new pollution controls), it is difficult to consider these controls as being implemented
early.
• The SO? limits of the FCPP FIP are not as stringent as BART. The commenter stated that
without a BART analysis for S02 for each of the FCPP units, it is not known how much
the current FIP requirements differ from what would have been required to meet BART.
The commenter indicated that EPA can only allow an alternative to BART as long as it
has been demonstrated to result in greater reasonable progress that BART. The
commenter noted that the permit for Desert Rock, which would also use Navajo coal,
limited S02 emissions to 0.06 lb/MMBtu. In addition, the commenter added that the
current S02 controls on Units 4 and 5 do not treat 100 percent of the flue gas - the EPA's
BART determination should evaluate the cost and visibility benefits of treating 100
percent of the flue gas for all units.
• FCPP must meet presumptive SO? BART limits at a minimum. The commenter pointed
out that the presumptive BART limit for EGUs like FCPP is 95 percent control, the
commenter asserted should be the regulatory floor. The commenter requested that EPA
undertake an S02 BART analysis for FCPP on a unit-by-unit basis and develop specific
limits for each unit. The commenter argued that a plantwide limit would only be
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acceptable if it ensured emission reductions that were better than what would be required
by a BART determination for each unit. The commenter added that the presumptive
limits may be BART, but this will be known only after a thorough BART analysis.
Finally, the commenter asked that EPA not delay the final NOx and PM BART
determinations while conducting the required SO2 BART rulemaking.
In "preliminary" comments submitted prior to the supplemental proposal, a similar group
of environmental advocacy groups (0095) suggested that the owners of FCPP should be required
to perform an SO2 BART analysis for all five units for submission to EPA and the public no later
than February 18, 2011, with comments due by the comment deadline that was then in force for
the BART rulemaking (i.e., March 18, 2011). The commenter further stated that EPA should
propose an S02 BART determination by April 30 and a final determination at the time it
finalized the FIP, with compliance with the SO2 BART limits required by 2014. The commenter
added that the BART determination should include a provision that FCPP may forego BART
implementation at any unit if it agrees to retire that unit prior to the deadline for BART
implementation. The commenter requested that these proposed requirements be published for
comment in any Federal Register notice published to take comment on the FCPP alternative
BART proposal.
A public interest advocacy group (0112) stated that the S02 limits need to be tightened up
for FCPP to further reduce visibility impairment and to reduce the acidification of rainfall caused
by the formation of H2S04. The commenter stated that because the damaging effects of H2S04 in
precipitation on ancestral Puebloan sandstone dwellings and pictographs are not fully
understood, it is disappointing for the FCPP proposals not to address S02. The commenter asked
that FCPP be required to perform a BART analysis for all five units by a date established by
EPA.
Response:
As many of the commenters acknowledge, EPA finalized a FIP in May 2007 that required
significant SO 2 emissions reductions from FCPP and established continuous SO 2 emissions
limits for FCPP. See 72 FR 25698 (May 7, 2007). The 2007 FIP required FCPP to increase the
removal efficiency if its SO2 emissions controls from 72% to 88%, resulting in a SO 2 emissions
reduction of approximately 22,000 tons per year. EPA had proposed this FIP in September 2006.
The 2006proposed FIP stated that "EPA believes that the SO2 controls proposed today for
FCPP are close to or the equivalent of a regional haze BART determination of SO 2- This takes
into consideration the early reductions this action will achieve and the modification to the
existing SO2 scrubbers. " 72 FR 25700. We received several comments on our 2006proposal
which stated that EPA should be undertaking a BART analysis for SO 2 rather than setting the
SO 2 emissions limit based on FCPP's agreement to improve its SO 2 removal efficiency from 72%
to 88%. In finalizing that rulemaking in the 2007 FIP, EPA responded that it was exercising its
authority pursuant to Section 49.11 of the TAR to implement measures that are necessary or
appropriate to protect air quality in Indian country. Id. EPA determined that the SO2 emissions
reductions would be federally enforceable as soon as the 2007 FIP was finalized which would be
potentially five years before EPA could achieve enforceable SO 2 emissions reductions through
making a BART determination. See id. EPA also considered the Navajo Nation's request for EPA
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to establish enforceable SO 2 emissions reductions immediately that, in the opinion of the Navajo
Nation, "appear[] to be equivalent to BART. " Id. Therefore, EPA's determination on this issue
in finalizing the 2007 FIP was "that it is neither necessary nor appropriate at this time to
undertake a BART determination for SO 2 from FCPP given the timing of the substantial SO 2
reductions resulting from this FIP. " Id. In addition, we stated that "given that the SO 2 controls
for FCPP immediately achieve significant reductions in SO2 comparable to what could
ultimately be achieved through a formal BART determination, EPA believes that it will not be
necessary or appropriate to develop a regional haze plan to address SO2 for the Navajo Nation
in the near term. " Id. 25700-701.Both APS, as operator of FCPP, and Sierra Club sought
judicial review of our 2007 FIP.
The comments on this action essentially repackage the comments we received and
provided a response for on the 2007 FIP. The comments have not presented any new facts or
legal considerations that have arisen or changed since we responded to comments requesting a
BART determination for SO 2 in 2007.
Comment:
One commenter (0182.3) submitted a technical review of S02 BART, which was attached
to the comments of an environmental advocacy group (0182). The commenter asserted that the
S02 FIP requirements do not reflect the level of S02 control currently being achieved at FCPP
Units 1-3. According to the commenter, a review of 2008 and 2009 SO2 emissions data
compared to APS data on annual uncontrolled S02 emissions in the coal show that these FCPP
units are achieving greater than 93 percent control on an annual average basis. Thus, the
commenter argued that the 88 percent control limitation cannot be considered as "close to or
equivalent to" BART and the emission limits for SO2 should be no higher than the removal
efficiencies actually being achieved.
The commenter (0182.3) provided a BART analysis for SO2 at FCPP Units 1-3 and
concluded that SO2 BART for FCPP Units 1-3 should be a 95 percent SO2 control requirement
or an emission limit of 0.09 lb/MMBtu, applicable to each unit on a rolling average basis of 30
boiler operating days. The commenter added that this BART limit would be met by the addition
of baghouses upstream of the existing wet scrubbers at these units (which will be required to
meet MACT and also PM BART), along with other physical or operational changes to the
scrubbers to improve SO2 removal efficiency to 95 percent. The commenter indicated that
compliance should be based on CEMS and, if a percent removal requirement is imposed, daily
sampling of sulfur in the coal from which daily percent SO2 removal is then determined with the
actual SO2 data from the CEMS. Finally, the commenter stated that these limits should apply on
a unit-by-unit basis to ensure that each unit is required to achieve the best continuous level of
emission reductions.
The commenter (0182.3) also asserted that the 2007 SO2 FIP requirements do not reflect
the level of SO2 control currently being achieved at FCPP Units 4 and 5. According to the
commenter, the annual data show that the FCPP Units 4 and 5 are achieving approximately 90 to
91 percent SO2 removal from the uncontrolled SO2 in the coal on an annual average basis. Thus,
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the commenter claimed that the 88 percent control limitation cannot be considered as "close to or
equivalent to" BART and the emission limits for S02 should be no higher than the removal
efficiencies actually being achieved.
The commenter (0182.3) stated that FCPP Units 4 and 5 are not meeting EPA's
presumptive BART limits of 95 percent SO2 control or an SO2 emission limit of 0.15 lb/MMBtu.
The commenter presented a BART analysis for SO2 at FCPP Units 4 and 5 and concluded that
S02 BART for FCPP Units 4 and 5 should be a limit of 95 percent S02 control based on EPA's
presumptive BART requirements, which would be achieved with the elimination of all scrubber
bypass along with other scrubber modifications necessary to improve S02 removal efficiency to
95 percent. At the minimum, the commenter asserted that SO2 BART for FCPP Units 4-5 should
be no less than a limit reflecting 92 percent control or 0.14 lb/MMBtu, as this would reflect the
level of control the FCPP Units 4 and 5 were designed for with the elimination of all scrubber
bypass. The commenter proposed the same compliance requirements set out above for Units 1 -
3.
Response:
As discussed in response to the prior comment, EPA finalized a FIP in 2007for FCPP.
EPA responded to comments in that FIP action suggesting that EPA should require FCPP to
achieve a 95% removal efficiency to be consistent with presumptive BARTfor SO2. The 2007 FIP
stated: "EPA disagrees with the comment that the BART Guidelines, 70 FR 39104, 39171 (July
6, 2005) establish a presumption that BART at FCPP is 95% control for SO 2. Although the BART
Guidelines did establish a presumption of either 95% control for SO 2 or 0.15 Ibs/MMBtu for
large power plants, this presumption applies only to power plants that are currently uncontrolled
or achieving less than 50% control of SO 2. Id. As indicated in the preamble to this proposed FIP,
this presumption thus does not apply to power plants, such as FCPP, with existing SO2 controls
achieving at least 50% removal efficiency. " Id. at 25700, n. 3. The comments here have not set
forth any new facts or changes in the law since we responded to this comment in 2007.
8.4 Other Comments on BART
Comment:
One group of environmental advocacy groups (0182) stated that as an alternative to a
condensable PM2.5 limit, EPA could set limits on the pollutants which form condensable PM2.5,
such as sulfuric acid mist (H2SO4) and ammonia, as EPA proposed as part of the SJGS BART
rulemaking (citing 76 FR 491, January 5, 2011). If EPA adopts this approach, the commenter
urged EPA to set an emission limit for H2SO4 no higher than the limit of 1.06 x 10"4 lb/MMBtu
for each unit as proposed for SJGS based on the use of low reactivity catalyst and the most
current information from the Electric Power Research Institute. If CEMS are unavailable for this
pollutant, the commenter urged EPA to require stack test monitoring for H2S04 on a more
frequent basis than annual monitoring.
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The commenter (0182) also requested that EPA set emission limits for ammonia at a rate
no higher than the 2.0 parts per million as proposed at SJGS, to be monitored with CEMs. The
commenter indicated that EPA should clarify in the final rule that the emission limits for H2SO4
and ammonia are being required under the Regional Haze program as part of a BART
determination for the facility and must be complied with within 3 years of the date of the final
rule.
In "preliminary comments submitted prior to the supplemental proposal, a similar group
of environmental advocacy groups (0095) suggested the same limits for ammonia and H2SO4
based on the proposed limits for SJGS. The commenter added that the BART determination
should include a provision that FCPP may forego BART implementation at any unit if it agrees
to retire that unit prior to the deadline for BART implementation. The commenter requested that
these limits be published for comment in any Federal Register notice published to take comment
on the FCPP alternative BART proposal.
Response:
EPA disagrees with the comment that Region 9 should set the same emission limits for
ammonia and sulfuric acid as Region 6 in its proposed BART determination for SJGS.
In its January 5, 2011 proposed rulemaking for SJGS, Region 6 proposed an ammonia
slip limit of 2.0 ppmvd on an hourly average and requested comment on a range from 2.0 ppmvd
to 6.0 ppmvd. In its final BART rulemaking (76 FR 52388, August 22, 2011), Region 6
determined that an emission limit and monitoring were not warrantedfor ammonia and did not
finalize its BART determination for SJSG with the proposed 2.0 ppmvd ammonia limit.
In its proposal for SJGS, Region 6 proposed an emission limit for sulfuric acid of 1.06 x
10~4 Ib/MMBtu on an hourly average, and requested comment on a range from 1.06 x 10~4 to 7.87
x 10~4 Ib/MMBtu. In its final rulemaking, Region 6 finalized an emission limit for sulfuric acid of
2.6 x 10~4 Ib/MMBtu to minimize its contribution to visibility impairment. Region 6 calculated
this emission limit using an estimation methodology from the EPRI, assuming the use of an ultra
low activity catalyst (0.5% total conversion of SO 2 to SO 3), zero ammonia slip, no sorbent
injection, and EPRI-recommended values for removal by existing downstream control
equipment.
Actual measurements of baseline sulfuric acid emissions have not yet been determined at
FCPP and the calculation of projected sulfuric acid emissions after installation and operation of
SCR using the EPRI methodology is dependent on future decisions made by the facility on the
type of SCR catalyst and number of layers used, as well as numerous assumptions about loss to
downstream components, such as air preheaters and baghouses, the true values of which are
currently not yet defined or known for FCPP., EPA Region 9 is the permitting authority for
preconstruction permits on the Navajo Nation, and an increase in sulfuric acid emissions from
the installation of SCR may trigger major modification PSD permit requirements at a low
threshold of 7 tpy (see 40 CFR 52.21) or Tribal minor new source review (NSR) permit
requirements at a threshold of 2 tpy (see 40 CFR Part 49 Subpart C). Preconstruction permitting
review may also be triggeredfrom significant emissions increases ofPM2.s from SCR installation
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at FCPP. If one of these pollutant triggers PSD, the permitting authority must provide an
Additional Impact Analysis under the PSD program. The PSD program also requires the
permitting authority to determine BACTfor pollutants that triggered PSD. A similar control
technology review may also be required at the discretion of the permitting authority under the
Tribal Minor NSR program. For these reasons, Region 9 has determined that for FCPP,
emission limits and monitoring requirements for sulfuric acid are more appropriately reviewed
in the preconstruction permitting process.
Comment:
Citing the BART Guidelines at 40 CFR part 51, Appendix Y, section V, one
environmental advocacy group (0182) stated that BART emission limits and compliance
schedules must be based on "boiler operating day." The commenter indicated that the NOx
BART proposal of 0.11 lb/MMBtu is based on a 30-day, calendar rolling average (citing 75 FR
64235) and the supplemental BART proposal is silent as to type of 30-day rolling average is
intended (citing 76 FR 10530).
The commenter (0182) claimed that the "very high" proposed BART emission limits
suggest that EPA set these limits to encompass spikes that occur during startups and shutdowns.
The commenter asserted that setting and enforcing limits based on boiler operating day would
necessarily exclude spikes that occur before and after outages, such as startups, shutdowns, and
malfunctions. According to the commenter, such periods should be subject to separate limits set
at the pre-SCR uncontrolled level to encourage good work practice standards during these
periods while allowing the SCR and other emission control technologies to be operated at an
efficient and continuous capacity in compliance with BART. The commenter argued that it is
clear that the BART Guidelines are based on establishing separate limits for emissions spikes to
avoid misapplying the Guidelines and setting unnecessarily high BART emission limits.
Response:
EPA agrees that the BART Guidelines specify that the permit (or implementation plan
that establishes the emission limitations), for EGUs must "specify an averaging time of a 30-day
rolling average, and contain a definition of "boiler operating day " that is consistent with the
definition in the proposed revisions to the NSPS for utility boilers in 40 CFR Part 60 subpart Da
(70 FR 9705, February 28, 2005) ". The proposed revisions to the NSPS in 2005 included a
definition for "boiler operating day
Boiler operating day for units constructed, reconstructed, or modified on or
before February 28, 2005, means a 24-hour period during which fossil fuel is
combusted in a steam generating unit for the entire 24 hours. For units
constructed, reconstructed, or modified after February 28, 2005, boiler operating
day means a 24-hour period between 12 midnight and the following midnight
during which any fuel is combusted at any time in the steam generating unit. It is
not necessary for fuel to be combusted the entire 24-hour period.
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The definition of boiler operating day was finalized on June 13, 2007 (72 FR 32 722) as
proposed.
EPA agrees that the N0X limit for the alternative proposal should be set for 30 successive
boiler operating days and that a "boiler operating day " should be defined as any day in which
the boiler fires fossil fuel and therefore includes periods of startup or shutdown. Because the
N0X emission limit under the alternative emission control strategy already includes periods of
startup or shutdown, separate limits are not required. The final rule reflects this approach.
For the original proposal, EPA does not find it necessary to define boiler operating day
because the limit is a heat input weighted plant-wide limit. Only operating hours for any of the 5
units would be included. When a unit is not operating, those hours are not included in the plant-
wide 30 day average. Additionally, the heat-input weighted plant-wide limit also includes
periods of startup and shutdown, therefore, separate limits are not required.
Comment:
One environmental advocacy group (0182) commented that EPA should require FCPP to
install all control equipment within 3 years of the date of a final FIP, as EPA did at the San Juan
Generating Station. The commenter stated that there is ample data to supporting the contention
that all this emission control technology can be installed and operational within 3 years or less.
Response:
EPA disagrees with the comment that EPA should set a 3 year compliance timeframe
because EPA proposed a 3 year compliance timeframe for SJGS. In its proposed rulemaking for
SJGS83, Region 6 proposed a 3 year timeframe for SJGS to comply with the proposed limits but
requested comment on a compliance range of 3 - 5 years. In its final rulemaking, Region 6
finalized a compliance timeframe of 5 years and determined that because of site congestion at
SJGS, a longer timeframe than average (37-43 months) to install SCR on the 4 units at SJGS
would be required. The final BART determination for FCPP requires retrofit of 5 existing units
at FCPP. In the final rule for FCPP, Region 9 is requiring installation and operation of SCR
controls for one 750 MW unit within 4 years of the effective date, and the remaining 750 MW
unit and Units 1 — 3 within 5 years of the effective date. Based on all of the factors that will be
involved in the design, purchase and operation of the SCR controls, Region 9 considers this
schedule to be appropriate and expeditious.
Comment:
One group of environmental advocacy groups (0095) stated in comments submitted prior
to publication of the supplemental proposal that FCPP has a large impact on visibility in the
region, and that time has come to eliminate these impacts. The commenter opined that it is
incumbent upon EPA to curtail these impacts to the maximum extent possible by issuing a strong
83 See 76 FR 491, January 5, 2011
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FIP addressing all visibility-impairing pollutants. (See the commenter's suggested limits for the
pollutants elsewhere in this section.)
In comments dated prior to publication of the supplemental proposal, a near-by county in
a neighboring state (0106) and an individual county commissioner (0108) supported EPA's
proposed action on FCPP because it will result in significant reductions in NOx and other haze-
forming pollutants that also negatively impact public health. The commenters noted that ozone
levels in the area have nearly reached nonattainment levels, and that the regional economy
thrives on the quality of the natural and historical resources which may be significantly
diminished by the presence of haze. In a resolution passed prior to publication of the
supplemental proposal, a near-by city in a neighboring state (0105) encouraged EPA to comply
with both the RHR and the CAA's "good neighbor" provisions and require BART on FCPP (and
SJGS) to reduce haze and to improve visibility and health in the Four Corners airshed.
A private citizen (0084) stated, in comments submitted after APS announced its intent to
purchase SCE's stake in Units 4 and 5 and to shut down Units 1-3 but prior to publication of
the supplemental proposal, that APS should continue with its proposed transactions and EPA
should continue to consider its proposed BART rule. The commenter argued that APS's plans
would result in a smaller reduction in emissions than would the BART proposal, but a
combination of the two would provide more jobs and economic stability and improve air quality.
Response:
As stated in other EPA responses within this document, a BART determination represents
a case-by-case determination that accounts for site specific characteristics in the five-factor
analysis. While choosing an emission limit that represents the lowest emission rate achieved by
similar facilities may be justified in some cases, the BART Guidelines do not specifically require
emission reductions "to the maximum extent possible As discussed in more detail elsewhere in
this RTC (See Section 8.1), EPA has determined that a plant-wide NOx emission limit of 0.11
Ib/MMBtu, representing an 80% reduction in plant-wide emissions and achievable by the
installation and operation of post-combustion controls, is BARTfor FCPP based on site-specific
considerations, including physical limitations of the boilers.
EPA has determined that finalizing a FIP implementing the BART provisions of the RHR
to reduce NOx emissions from FCPP on the Navajo Nation is appropriate at this time. EPA
expects the NOx reductions required for FCPP in the final FIP, combined with the NOx
reductions required in the final FIP for SJGS issued by EPA Region 6 (76 FR 52388, August 22,
2011), will contribute to improved air quality in the Four Corners area; therefore a FIP for the
Navajo Nation implementing the "goodneighbor "provisions under the Clean Air Act (Section
110(a)(2)(D)(i)) is not necessary at this time.
EPA disagrees with the commenter that the alternative emission control strategy would
result in smaller emission reductions compared to our final BART determination. As outlined in
more detail elsewhere in this RTC (See Section 9.0), EPA has determined that the alternative
emission control strategy will result in greater annual emission reductions than BART.
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Comment:
One public interest advocacy group (0112) stated that EPA should hold FCPP to the
highest possible level of monitoring and validation of the FIP. The commenter indicated that this
is justified by the fact that FCPP previously discontinued use of a re-heat of the scrubber exhaust
on Units 1-3 without authorization from EPA.
Response:
EPA agrees that monitoring, record-keeping, and reporting requirements are critical
elements in enforcing the emission rates established in the final FIP. As stated in the proposed
BART determination, the final BART determination requires FCPP to comply with 40 CFR Part
75 requirements, including requirements related to quality assurance testing, relative accuracy
test audits. The requirements of the final FIP will be incorporated by the Navajo Nation
Environmental Protection Agency (NNEPA) into the facility's Part 71 Operating Permit, and
will require FCPP to submit annual compliance reports and testing results to the NNEPA and
EPA Region 9.
EPA was never notified of the discontinued use of the reheaters for Units 1-3. EPA is not
aware of when these units were taken out of service. Although EPA would have appreciated the
opportunity to weigh in on this decision, we are not aware of any regulation that would have
prevented APS from removing the re-heaters.
These 3 units do not have an opacity limit under the 2007 FIP, so the wet stack and lack
of continuous opacity monitors should not be a monitoring issue. They are required to monitor
and report deviations of the pressure drop and scrubber liquid flow to the venture scrubbers to
assure proper operation of these control devices for PM.
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9.0 Comments on APS's Alternative Proposal and EPA's
Supplemental Proposal
Comment:
One of the owners of FCPP (0176/0177) pointed out that the November 2010 APS
proposal included two critical components: (1) a proposal to close Units 1-3 and install SCRs
on Units 4 and 5; and (2) EPA's contemporaneous agreement that these activities resolve any
liability FCPP may have under regional haze BART, Reasonably Attributable Visibility
Impairment Best Available Retrofit Technology (RAVI BART), NSR, and NSPS. The
commenter asserted that EPA's supplemental proposal addresses only half of APS's proposal -
the half that achieves better than BART emission reductions, plant-wide reductions of all other
emissions, and greater visibility improvement at nearby Class I areas - but ignores the other half
of the APS proposal - the half that provides APS and the FCPP co-owners with needed
regulatory certainty. Unless there is a contemporaneous resolution of these key issues with EPA,
the commenter cannot and does not support EPA's supplemental proposal. With a full resolution
of these issues, the commenter would then support the supplemental proposal.
In the November 2010 APS proposal, APS explained that it proposed the alternative
strategy because it was faced with uncertainty on all sides. The commenter (0176/0177)
indicated that FCPP must resolve these uncertainties before spending significant capital on
upgraded pollution controls. For this reason, the proposal to install SCRs on Units 4 and 5 in
2018 is inexorably linked with EPA's contemporaneous agreement to resolve any plant
obligations under the referenced programs.
Another of the owners of FCPP (0168) similarly rejected the supplemental proposal
without contemporaneous resolution of all obligations that FCPP may have related to the CAA
programs listed above. The commenter added that it would consider accepting the supplemental
proposal if these other potential issues are resolved, but emphasized that acceptance of the
supplemental proposal would be voluntary and based on its own business interests.
Response:
EPA understands that the owners of FCPP are seeking to resolve any potential
regulatory noncompliance at a roughly simultaneous time. However, EPA must use different
mechanisms for promulgating rules and resolving enforcement issues. The comment requests
resolution ofpotential past non-compliance with NSR and NSPS requirements. Potential past
non-compliance can be resolved through entering into a Consent Decree containing a judicially
approved release from liability. Such a Consent Decree under the Clean Air Act must be
approved by the United States Department of Justice and must also be lodged in a United States
District Court where the public is allowed to comment on it. Consent Decrees must be entered by
the United States District Court for a release of liability ofpotential past non-compliance to be
effective. Accordingly, this rulemaking action cannot effectuate any release of liability for
potential past non-compliance with NSR or NSPS.
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The comment is also seeking some resolution with respect to a potential finding by the
Department of Interior that visibility impairment at a Class I area is reasonably attributable to
FCPP 's emissions. If the Department of Interior made such a finding, then EPA would be
obligated to determine whether EPA should make a BART determination.
EPA is aware that several environmental groups have petitioned the Department of
Interior to make a finding that impairment at Class I areas is reasonably attributable to FCPP.84
The NPS, on behalf of Department of Interior, has declined to make such a finding based on
EPA's work in this rulemaking.85 The environmental groups also filed a Complaint in the United
States District Court for the District of Columbia86 contending that the Department of Interior
was unreasonably delaying making a finding of reasonable attribution from FCPP. On June 30,
2011, the Court dismissed the Complaint87 holding that the NPS's letters refusing to make the
finding of reasonable attribution constituted denying the Petitioners' request for a RA VIfinding.
Therefore, there are no pending petitions with the Department of Interior requesting a finding
that visibility impairment at any Class I areas is reasonably attributable to FCPP. In any event,
a BART determination under RA VI would likely be the same as under this BART determination.
Comment:
One public interest advocacy group (0112) requested that EPA publicly disclose (to the
extent legal counsel will allow) how each of the conditions set forth in the APS proposal (i.e.,
related to RAVI BART, NSR, and NSPS violations) is incorporated into and/or is accommodated
by the EPA's supplemental proposal.
Response:
As discussed above, EPA can resolve potential past non-compliance with NSR and NSPS
through entering into a Consent Decree approved by the Department of Justice and lodged in the
United States District Court. The public will have an opportunity to comment on any Consent
Decree and may request the Court to determine whether the Consent Decree is in the public
interest.
Although EPA does not believe that there are any pending petitions to the Department of
Interior to make a finding that the visibility impairment at any Class I area is reasonably
84 See National Parks Conservation Association, et al., Petition to United States Department of Interior, United
States Department of Agriculture, and United States Forest Service, February 16, 2010, in the docket for this
rulemaking.
85 See letter from Will Shafroth, Department of Interior to Stephanie Kodish, NPCA, March 8, 2011 in the docket
for this proposed rulemaking.
86 See National Parks Conservation Association, et al., Petition to United States District Court for the District of
Columbia, January 20, 2011, in the docket for this final rulemaking.
87 See National Parks Conservation Association, et al., Plaintiffs, v. United States Department of Interior and United
States Department of Agriculture, Defendants. Civil Action No. 11-130 (GK). United States District Court for the
District of Columbia, June 30, 2011, 794 F. Supp. 2d 39; 2011 U.S. Dist. LEXIS 70170; 74 ERC (BNA) 1015. In
the docket for this final rulemaking.
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attributable to FCPP's emission, EPA also considers any BART determinations it makes to
consider the same factors whether the BART determination is triggered by a finding of
reasonable attribution or under 40 CFR 51.308(e).
Comment:
One of the owners of FCPP (0176/0177) stated that it is imperative to note that its support
of the supplemental proposal (if other potential liabilities are resolved as discussed above) is
based solely on the rationale that this achieves a result better than the proposed BART FIP, and
that this "better than BART" outcome is a result of the closure of Units 1, 2, and 3. The
commenter stressed that in no case - either in the original BART FIP proposal or in the
supplemental proposal - does the commenter support any determination that SCR constitutes
BART for FCPP. A second FCPP owner (0168) stated that its acceptance of the supplemental
proposal upon resolution of the other potential issues would be a voluntary action based on its
own business interests; the commenter does not support any BART determination that calls for
installation of SCR at FCPP.
Another of the FCPP owners (0174) similarly emphasized the belief that SCR cannot be
justified as BART at FCPP. Accordingly, the commenter stated that EPA's October 2010 BART
proposal should not be used as the benchmark for evaluating and proposing a BART alternative.
The Navajo Nation (0223) also did not agree that SCR is BART for FCPP.
Response:
EPA disagrees with the commenter s that SCR is not BART. Based on our five-factor
analysis, as described in the TSD for our proposed BART determination, SCR is cost effective
and results in the greatest anticipated improvement in visibility. One of the owners of FCPP
notes that the "better-than-BART" outcome is a result of the closure of Units 1, 2, and 3.
However, the closure of Units 13 alone does not result in greater emission reductions than
EPA's proposed BART determination, and represents only a roughly 30% reduction from
baseline emissions. The closure of Units 1-3, in combination with SCR on Units 4 and 5, results
in the "better-than-BART" outcome.
The voluntary nature of the alternative emission control strategy does not negate EPA 's
BART determination because (1) EPA must determine what BART is in order to fulfill the
requirements of the alternative program to BART as prescribed in the RHR, and (2) EPA cannot
require the full or partial closure of a facility as a BART alternative, therefore the alternative
emission control strategy remains an optional business choice of the owners of FCPP to
implement in lieu of BART, if they see fit.
Comment:
Eleven private citizens (0122, 0139, 0140, 0141, 0145, 0149, 0158, 0159, 0166, 0167,
0201) expressed general support for the supplemental proposal, although five of these
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commenters (0122, 0145, 0156, 0158, 0167) did not support the 2018 completion date. One
commenter (0167) preferred a completion date within 3 years of the final EPA decision, two
commenters (0122, 0158) preferred a completion date of 2014, and one commenter (0145)
asserted it cannot wait until 2014.
One of the private citizens (0139) supported the supplemental proposal with a few
changes: (1) APS should be required to implement the upgrades incrementally over the next
7 years, with l/7th of the work to be completed each year, (2) penalties should be enforced for
any year in which they lag behind the schedule, (3) retirement of the existing units should follow
the same schedule, and (4) clean-up of the existing sites, incrementally, over the 7 years.
Another of the private citizens (0159) stated that the supplemental proposal yields even
greater emissions reductions than the original BART proposal, promising greater health and
economic benefits at significantly lower cost to the utilities and their ratepayers. The commenter
also noted that APS and BHP Billiton pledged that no layoffs would be associated with the
shutdown of the three smaller units at FCPP under this proposal.
A third private citizen (0167) urged EPA to lower the proposed numeric limits on NOx
and PM and to add limits for ammonia and H2SO4. The commenter argued that such limits would
mean healthier air for us all, better views of our magnificent national parks, and a stronger
tourism economy.
Several other commenters (0108, 0112, 0113, 0143, 0150, 0152, 0175, 0183, 0192, 0200,
0223) also expressed support for the supplemental proposal, although some indicated some
reservations about certain aspects of the proposal. These comments are summarized in the
following paragraphs.
The Navajo Nation (0223) tentatively supports the supplemental proposal with the
following caveats:
• The alternative emission control strategy must be determined through government-to-
government consultation with the Navajo Nation and give primary consideration to the
economic interests of the Nation in the continued operation of FCPP. (See Section 4.1 for
more detail.)
• The Navajo Nation does not agree to a determination that SCR is BART for FCPP.
The commenter (0223) agreed that the supplemental proposal would result in 100 percent control
of NOx, SO2, PM, mercury, and other hazardous pollutants by shutting down Units 1 - 3 by
2014, which would significantly reduce the emissions of FCPP.
One state air agency (0113) anticipated substantial environmental benefits for the Four
Corners region from the alternative proposal, and from an air emissions standpoint regarded this
alternative proposal as superior to the October 2010 BART proposal. The commenter indicated
that because the alternative proposal appears to have support from the facility's operators, it
should result in a higher likelihood of long-term success. The Attorney General's office (0200)
from the same state supported these comments. A U.S. Senator (0150) from the same state also
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expressed support for the supplemental proposal because it would help to address longstanding
concerns with air quality in the Four Corners region at a lower cost than the initial BART
proposal. This commenter noted that the Class I areas affected by FCPP (and SJGS) are drivers
of the economy in Southwest Colorado, and that emission from the plants have caused a variety
of negative public health impacts.
One federal agency (0175) supported the supplemental proposal, but would prefer a NOx
limit of 0.05 lb/MMBtu (as discussed in Section 8.1). The commenter agreed that the
supplemental proposal would provide greater visibility improvement in the surrounding Class I
areas than EPA's original BART proposal of October 2010, as well as additional benefits such as
reduced water consumption and reduced CO2, SO2, and mercury emissions. An environmental
advocacy group (0183) similarly supported the supplemental proposal (with a lower, but
unspecified, NOx limit) and stressed the health and ecosystem benefits that would result from
lower emissions of NOx, PM, S02, mercury, and C02 (which are discussed further in
Section 4.2).
One public interest advocacy group (0143) and one private citizen (0192) supported
EPA's supplemental proposal for FCPP. The private citizen (0192) specifically supported the
shutdown of Units 1 - 3 by 2014 and application of a NOx limit of 0.098 lb/MMBtu for Units 4
and 5 with a compliance date of July 31, 2018. Given that SCR is a mature technology, EPA
originally proposed BART in October 2010, and FCPP has operated with only minimal air
emissions control for over 40 years, the commenter asserted this compliance schedule is ample.
The commenter also voiced support for providing flexibility to FCPP through setting the limit as
heat-input weighted limit and through a lower NOx limit on a 3-year rolling average.
One Tribe in the Four Corners area (0152) approximately 60 miles north of FCPP
supported the supplemental proposal. The commenter gave the following reasons for this
support: (1) any reductions in emissions from FCPP will result in cleaner and healthier air on the
Reservation; (2) the tribe's two air monitors show that the Reservation is nearing nonattainment
status for ozone, and reducing NOx emissions from FCPP may help maintain attainment; and
(3) any improvement in visibility in the Class I areas in the region will positively affect visibility
on the Reservation.
Another public interest advocacy group (0112) similarly expressed support for adding
regulatory language to the proposed BART determination for FCPP that would allow FCPP to
implement the alternative control strategy in lieu of having to implement EPA's proposed
BART. This commenter also indicated support for the option of adding a NOx emission limit
requiring greater than 80 percent control over longer averaging times weighted for heat input.
However, this commenter (0112) added that EPA should not make a final decision on
whether to accept the alternative control strategy until it receives a "professional and credible"
cost accounting of FCPP's costs, including the additional pollution control investments for
Units 4 and 5. The commenter indicated that the cost accounting should explain where the
money will come from for retirement of Units 1-3 and for pollution control upgrades for
Units 4 and 5.
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The commenter (0112) also questioned EPA's statement that the alternative emission
control strategy to shut down Units 1 - 3 by 2014 not only results in 100 percent control of NOx,
but also 100 percent control of all other pollutants emitted by those units. The commenter alleged
that this is a misleading statement because the shutdown of Units 1 - 3 is simply a business
decision; the emission reductions are not attributable to any CAA program or enforcement of
controls by EPA. The commenter stated that the "100 percent control" wording paints too rosy a
picture by using the ratio of emissions after shutdown to emission levels that are completely
unacceptable at present. According to the commenter, FCPP remained the most polluting power
plant in the United States as of March 20, 2011.
Response:
EPA has reviewed the comments in general support of our Supplemental Proposal.
Specific comments on revisions to various aspects of the alternative emission control strategy,
such as compliance timeframes, emission limits for sulfuric acid and ammonia, lower limits for
NOx, health and ecosystem benefits, disagreement that SCR is BART, and the interests of the
Navajo Nation, are included and addressed in more detail elsewhere in this Section and more
broadly within this document (e.g., Sections 4 and 8).
Regarding the timing of the installation of controls, EPA disagrees with commenter s that
the compliance date for the alternative to BART should occur earlier than 2018, or that EPA
should impose incremental progress in NOx reductions over the intervening 7 years. As
described in our Supplemental Proposal, in order to implement the alternative emission control
strategy, APS and other owners of FCPP must receive approvals from three regulatory agencies
as well as finalize coal contract negotiations with BHP Billiton, and receive approval from DOI
on the lease agreement with the Navajo Nation. These various components take time, as does the
actual planning and installation of SCR as retrofits on existing boilers, Units 4 and 5. Therefore,
the year 2018 compliance timeframe for the alternative emission control strategy in our final
rulemaking is reasonable and appropriate.
EPA disagrees with the comment that EPA should not make a decision on the alternative
emission control strategy until it receives a "professional and credible " cost accounting of
FCPP's costs for Units 4 and 5. Under the RHR (see 40 CFR §51.308(e)(2)), a cost analysis is
not required element for an alternative to BART analysis. Even though EPA has not done a cost
analysis of this alternative emission control strategy, EPA expects the cost of the alternative is
likely to be lower than the cost of BART because the BART Alternative involves installation of
additional controls on fewer units at FCPP.
EPA disagrees with commenters who contend that our statement that the closure of Units
1 — 3 at FCPP results in 100% control of those units is misleading. If Units 1 — 3 close, those
three units will not emit any air pollutants, i.e., 100% control. EPA further notes that the
alternative emission control strategy not only involves closure of Units 1-3, but also
installation of SCR on Units 4 and 5, further reducing facility-wide emissions ofNOx.
Comment:
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The Navajo Nation (0223) agreed that shut down of Units 1, 2, and 3 by January 2014
and installation of SCR on Units 4 and 5 by July 31, 2018, in order to satisfy the requirements of
CAA section 169A(b)(2) and the RHR, 40 CFR 51.308(e), is realistically achievable. The
commenter noted that EPA recognized in the supplemental proposal that APS must obtain
approvals from several agencies, and that the Navajo Nation Council recently endorsed a lease
renewal for FCPP; however, the lease renewal process is not yet complete as the lease renewal
still needs to be reviewed and approved by the DOI, which the commenter stated will likely
include review required under NEPA. The commenter indicated that if the final approval is
delayed, there may be associated delays in compliance scheduling.
The commenter (0223) expressed appreciation for EPA's understanding of the
complexities related to the lease renewal that could delay the finalization of lease, including
right-of-way issues that could also impact the life of FCPP. The commenter requested that EPA
continue to provide flexibility to allow the leasing process to be completed.
Response:
EPA has reviewed the Navajo Nation's comments agreeing with the timing of the
alternative emission control strategy. As noted in the comment, EPA is aware that the lease
approval process through DOI will take time, as will the approval of the sale of Southern
California Edison's share of Units 4 and 5 to APS. Our final rulemaking requires a compliance
timeframe for the alternative emission control strategy no later than July 2018.
Comment:
One environmental advocacy group (0182) and one federal agency (0224) asserted that
the supplemental proposal is not better than BART for NOx. The commenters provided
somewhat different rationales for this assertion, as summarized below.
The environmental advocacy group (0182) argued that the supplemental proposal is not
better than BART for at least three reasons. The commenter indicated that to qualify as "better
than BART," an alternative must achieve "greater reasonable progress towards achieving
national visibility conditions" than BART by resulting in "greater emissions reductions" than
BART [citing 40 CFR 51.308(e)], The commenter stated that the alternative put forward by EPA
fails to meet these requirements as follows:
• The alternative proposal's delayed compliance date results in fewer emission reductions
as compared to those emission reductions that should be required to begin occurring no
later than 5 years after plan approval.
- The CAA requires BART to be installed no later than 5 years after EPA's final
rulemaking [citing 42 U.S.C. 7479A(b)(2)(A)]. By offering FCPP a BART
compliance deadline of July 2018, EPA is illegally extending a mandatory deadline
under the CAA. See Sierra Club v. EPA, 129 F.3d 137, 140 (D.C. Cir. 1997); Sierra
Club v. EPA, 719 F.2d 436, 469 (D.C. Cir. 1983). Furthermore, installation of SCR at
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Units 4 and 5 can be accomplished easily within 2 years (citing Comment 0182),
making a 7-year "grace period" for BART compliance unnecessary.
- To justify this delay, EPA links the extended deadline to the end of the first long-term
strategy period for regional haze [citing 76 FR 10535; 40 CFR 51.308(e)(2)(iii)], but
these are separate and distinct deadlines. While the statute requires the installation
and operation of BART within 5 years, the purpose of the first long-term strategy
deadline is to ensure that those already-imposed reductions are actually working.
Also, the BART regulations require "all necessary emissions reductions [to] take
place during the period of the first long-term strategy for regional haze" [citing 40
CFR 51.308(e)(2)(iii)], but the alternative proposal violates this requirement by
deferring the required BART reductions until the very end of this period.
• Use of an artificially inflated baseline, coupled with the potential increase in output from
Units 4 and 5, renders the claimed emissions reductions largely illusory. The commenter
quoted Comment 0182 as saying that EPA's analysis incorrectly assumes that all five
units currently operate at a 91 percent capacity factor when, in fact, they all operate at
lower levels, which artificially inflates the baseline from which EPA calculated the
alternative's emission reductions. On the other side of the equation, EPA underestimated
potential emissions from increased output at Units 4 and 5 (i.e., beyond 91 percent) to
make up for the lost generation from the shutdown of Units 1-3.
• The proposed emission limits do not constitute BART (see Section 8.1). The commenter
cited comments prepared by NPS (submitted as an attachment to Comment 0182) which
found that based on the assumption that SCR can achieve 0.05 lb NOx/MMBtu on an
annual basis, after 2016 the BART alternative would fail to achieve greater cumulative
NOx reductions than would installation of BART (SCR) on all five units. (See the
paragraph below for more on this NPS comment.).
As noted by the previous commenter, based on its assumption that NOx BART for all five
units at FCPP should be 0.05 lb NOx/MMBtu on an annual basis, the federal agency (0224)
found that after 2016 the BART alternative would fail to achieve greater cumulative NOx
reductions than would installation of BART (SCR) on all five units. (These calculations were
made assuming that Units 4 and 5 would also achieve a NOx emission rate of 0.05 lb/MMBtu on
an annual basis under the supplemental proposal, and were projected out to 2028.) In order to
achieve greater cumulative reductions than BART, the commenter identified an "Accelerated
BART Alternative" that would include shutdown of Units 1-3 by 2014, as proposed, plus require
that SCR be operational on Unit 4 by the beginning of 2017 and on Unit 5 by the end of
September 2017, 10 months sooner than proposed by EPA.
Response:
EPA disagrees with the comment that the alternative emission control strategy is not
better than BART, but agrees that a reexamination of baseline emissions and projected capacity
factors in the future is warranted. In our Supplemental Proposal, we relied upon the baseline
emissions APS provided of45,132 tons NOx per year, representing a 91% capacity factor on all
units. We examined annual emissions reported by FCPP to CAMD, and calculated average
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annual N0X emissions over 2001 - 2010 of42,395 tpy.88 As reported in the TSD for our
proposed BART determination, facility-wide N0X emissions over 2001 - 2009 ranged from
40,331 to 47,300 tpy. While the baseline emissions provided by APS and used by EPA in our
Supplemental Proposal was within the range of annual N0X emissions, in response to these
comments, we conducted an additional analysis to compare the alternative emission control
strategy against our final BART determination for N0X using the 2001 - 2010 average as the
baseline emission rate and an assumed capacity factor of 81% for Units 4 and 5 under the
alternative emission control strategy.89 We assume no change in capacity factors of Units 1 - 5 if
all 5 units continue operation under the BART scenario. Based on heat input reported to CAMD
and maximum capacity heat input reported in the Part 71 permit for FCPP, we calculate the
average capacity factor for Units 4 and 5 over 2001 - 2010 to be 76% and 75% respectively.
This analysis shows that in 2014 and 2015, the alternative emission control strategy results in
lower N0X emissions than BART due to the closure of Units 1 - 3 at the end of 2013. In 2016,
2017, and 2018, BART results in lower emissions than the alternative, and in 2019 and beyond,
the alternative emission control strategy (5,556 tpy), with phased-in controls on Units 4 and 5 by
the end of 2018, results in lower emissions than BART (8,479 tpy). For comparison, our analysis
from the Supplemental Proposal using a capacity factor of 91% resulted in emissions under the
alternative from 2019 and beyond to be 5,798 tpy, and under BART to be 9,026 tpy. In total, the
alternative results lower emissions from FCPP over more calendar years (2014-2015, and 2019
and beyond) than does BART (2016-2018). Even if APS operated Units 4 and 5 at 100%
capacity, EPA calculates that emissions under the alternative emission control scenario in 2019
and beyond to be 6,859 tpy, which is still lower than under BART. On a cumulative basis, i.e.,
the sum total ofNOx emissions over 2011 to 2064, the BART Alternative also results in lower
emissions than BART, both at an 81 percent capacity factor and at 100 percent capacity.
Commenters argue that if the BART emission limit were lower, the alternative would not
be better than BART. For example, if EPA required an emission limit representing a 90%
reduction in N0X emissions, annual N0X emissions would be lower than 5,000 tpy. However, as
discussed in great detail elsewhere in this RTC (See response to comments in Section 8.1), EPA
has determined that an 80% reduction in N0X emissions is BARTfor FCPP. It is inappropriate
to compare the alternative emission control strategy against a target for BART that commenters
would like to see based on maximum emission reductions achieved without consideration of site-
specific characteristics of FCPP.
Commenters further argue that by offering FCPP a BART compliance deadline of July
2018, EPA is illegally extending a mandatory deadline under the CAA, and that installation of
SCR at Units 4 and 5 can easily be accomplished within 2 years. EPA disagrees and notes that
the compliance timeframe for EPA's BART determination requiring SCR installation on all 5
units is within 5 years of the effective date of the final rule, consistent with the maximum time
allowed under the CAA §169A(g)(4) in the definition of "as expeditiously as practicable The
commenter is confusing requirements under BART and requirements under the alternative to
BART. EPA is not extending the BART compliance deadline beyond a 5 year period. Rather,
88 See: "data 01-10" tab in "BART v Alternative.xlsx" in the docket for this final rulemaking.
89 In testimony to the ACC, Mark Schiavoni of APS testified that he anticipates capacity factors over 2015 - 2030 to
range from 75 - 81% for Units 4 and 5 (See document titled "Schiavoni Testimony_TRANSCRIPT,pdf' in the
docket for this final rulemaking).
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EPA is allowing additional time to implement the alternative emission control strategy, as
allowed under the provisions of the RHR for the implementation of "other alternative measure
rather than to require sources subject to BART to install, operate, and maintain BART" (See 40
CFR §51.308(e)(2)).
EPA disagrees with commenters that reductions under the alternative to BART violates
40 CFR §51.308(e)(2)(iii). The requirement simply states the reductions take place during the
period of the first long term strategy and does not specifically prescribe that those reductions
must take place at the beginning, middle, or end of the period of the first long term strategy.
Based on the foregoing discussion and the calculations provided in our docket, EPA
confirms our previous determination that the alternative emission control strategy will result in
greater N0X emission reductions than BART in 2019 and into the future.
Comment:
To evaluate the supplemental proposal's impact on S02 emissions, one federal agency
commenter (0224) assumed that the scrubbers on Units 4 and 5 would be upgraded (perhaps by
conversion to a wet stack) concurrently with the SCR installation to achieve 0.12 lb/MMBtu.
Based on this assumption, the commenter confirmed that both the supplemental proposal and the
commenter's "Accelerated BART Alternative" (see comment above) would be better than BART
at 0.12 lb/MMBtu or current emissions levels.
This commenter (0224) also noted that EPA has stated that the supplemental proposal
would result in significant reductions of all relevant pollutants, including a 30 percent reduction
in the FCPP's carbon footprint. The commenter confirmed this for CO2 emissions based on
figures from CAMD from 2005-2010. According to the commenter, Units 1-3 accounted for an
average of 5,056,802 tpy of CO2 emissions out of a total of 15,499,044 tpy at FCPP during this
period.
Response:
EPA agrees with the commenter that the Supplemental Proposal will result in emission
reductions beyond what would be achieved by the NOx BART determination for multiple
pollutants. As discussed in the Supplemental Proposed Rule (76 FR 10537), the shutdown of
Units 1 through 3 will result in significant additional reductions of NOx, as well as reductions of,
PM, SO2, CO2, and mercury emissions that would otherwise not be achieved by the NOx BART
determination.
Comment:
One environmental advocacy group (0182) supported APS's "business decision" to close
Units 1-3, but characterized the company's alternative proposal as an attempt to leverage this
business decision into a 2-year extension of time to install BART on Units 4 and 5. The
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commenter noted that the BART regulations are clear that installation of controls is to occur
within 5 years, or sooner if practicable. Therefore, the commenter asserted that it would be
illegal for the EPA to extend the deadline for BART upgrades at Units 4 and 5 beyond the
mandated 5-year or less timeframe.
The commenter (0182) noted that EPA refers to the supplemental proposal as an
alternative to BART under 40 CFR 51.308(e), but the commenter stated that this regulatory
provision is inapplicable in the circumstances of this case. Based on the commenter's reading of
40 CFR 51.308(e), the commenter indicated that the supplemental proposal fails as an alternative
to BART because it does not address all the BART-eligible sources on the Navajo Nation - NGS
is also a BART-eligible source. The commenter also alleged that the supplemental proposal does
not qualify as an alternative to BART under the rules because, as discussed above, the
commenter asserted that the alternative will not "achieve greater reasonable progress than would
have resulted from installation and operation of BART" for NOx at all FCPP units during the
period of the first long-term strategy for regional haze.
Response:
EPA disagrees with these comments. The motivation, whether financial or environmental,
behind APS's proposal to close Units 1 - 3 is not relevant to the analysis, as discussed in other
EPA responses to comments in this Section, complies with the requirements of the RHR for
implementing an alternative to BART (See 40 CFR §51.308(e)(2)(iii)). EPA further notes that
our final BART determination of installing SCR on all 5 units requires compliance with the final
BART limits within five years of the effective date of the final rule, consistent with the
compliance timeframes in the CAA (See CAA §169A(g)(4)) and the RHR (See 40 CFR
§51.308(e)(l)(iv)). As stated previously, these comments confuse the requirements of an
alternative to BART with the requirements of a BART determination.
EPA also disagrees with the commenter's reading of 40 CFR §51.308(e) that the
Supplemental Proposal fails as an alternative to BART because it does not address all BART-
eligible sources on the Navajo Nation (i.e., Navajo Generating Station). The provisions of the
RHR describing the requirements for an alternative measure to BART (i.e., see 40 CFR
§51.308(e)(2)(i)(B)) states:
The State is not required to include every BART source category or
every BART-eligible source within a BART source category in an
alternative program, but each BART-eligible source in the State
must be subject to the requirements of the alternative program,
have a federally enforceable emission limitation determined by the
State and approved by EPA as meeting BART in accordance with
section 302(c) or paragraph (e)(1) of this section, or otherwise
addressed under paragraphs (e)(1) or e(4) of this section.
The RHR allows some sources to be included under the alternative program, and some sources
to meet BART (i.e., paragraph (e)(l) of the RHR at 40 CFR §51.308) or the CAIR (i.e.,
paragraph (e)(4) of the RHR at 40 CFR §51.308). As long as all BART-eligible sources are
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subject to either the BART alternative, a BART limitation, CAIR, or a federally enforceable
emission limitation determined to meet BART, the requirements of the RHR under 40 CFR
§51.308(e) are met. EPA agrees thatNGS is the other BART-eligible source on the Navajo
Nation. EPA Region 9 intends to propose a BART determination for NGS in addition to finalizing
our BART determination and the alternative emission control strategy for FCPP.
As described in detail in another EPA response to a comment within this Section of the
RTC, EPA has determined that the alternative will achieve greater reasonable progress than
would be achieved through the installation and operation of BART at FCPP.
Comment:
One of the owners of FCPP (0176/0177) and a utility industry association (0187) stated
that EPA has the legal authority to implement an alternative emission control strategy, provided
the plant owners agree to that strategy. The commenters indicated that the BART rules [40 CFR
51.308(e)] establish that alternative emission control measures that achieve greater reasonable
progress than BART - as "greater reasonable progress" is defined in EPA's rules - may properly
be adopted and implemented in lieu of BART. The commenters presented the history of related
legal cases and added that the authority for those regulations has been confirmed in three cases
by two different federal appellate courts. Central Arizona Water Conservation District v. EPA,
990 F.2d 1531 (9th Cir. 1993); Center for Energy and Economic Development v. EPA, 398 F.3d
653 (D.C. Cir. 2005); Utility Air Regulatory Group v. EPA, 471 F.3d 1333, 1340-41 (D.C. Cir.
2006).
Response:
EPA agrees with this comment and notes that our final rulemaking provides the owners
of FCPP the option of implementing the alternative emission control strategy in lieu of BART.
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10.0 Other Comments
Comment:
Forty-five private citizens (0087, 0088, 0089, 0091, 0118, 0119, 0123, 0125, 0127, 0128,
0129, 0130, 0135, 0136, 0137, 0138, 0140, 0141, 0144, 0147, 0149, 0153, 0154, 0155, 0156,
0157, 0158, 0162, 0170, 0171, 0172, 0173, 0181, 0186, 0188, 0190, 0198, 0199, 0201, 0202,
0208, 0209, 0210, 0211, 0213, 0214) explicitly stated that they support EPA's efforts to clean up
FCPP. Many of these commenters asked for the strictest regulations. Another private citizen
(0093) implied that EPA should act to clean up emissions from FCPP and noted that cleaner air
will result in a cleaner Colorado snow pack, which will result in cleaner water in the Colorado
River.
Twelve private citizens (0092, 0122, 0126, 0133, 0134, 0145, 0157, 0161, 0172, 0190,
0195, 0213, 0214) stated that FCPP should be de-commissioned. Several of these commenters
argued that the plant should only be shut down if it cannot cease emitting pollutants, while others
argued the plant should be shut down immediately. One of the latter commenters (0092) stated
that if FCPP is not de-commissioned, it should be retrofitted with BART. Another of these
commenters (0133) does not asserted that either of the two proposals is sufficient. In contrast,
one private citizen (0135) finds either of the proposals to be sufficient.
Nine private citizens (0122, 0126, 0134, 0140, 0145, 0170, 0186, 0190. 0195, 0197)
recommended that renewable energy sources can be used in place of coal-fired power plants.
Response:
EPA acknowledges the comments supportive of our proposals but disagrees with
commenters that suggest that FCPP should be de-commissioned or shut down immediately.
In addition to other CAA programs, EPA assesses air quality with respect to NAAQS.
The Four Corners area is designated attainment for each of the NAAQS.90 This means that the
air quality in the Four Corners area is meeting the national health-based standards set by EPA.
For this action, EPA finds that under 40 CFR 49.11, it is necessary or appropriate to
achieve emissions reductions of NO x from FCPP required by the CAA's RHR program. NOx is a
significant contributor to visibility impairment in the numerous mandatory Class I Federal areas
surrounding FCPP. The emission reductions finalized will help achieve the goals of the RHR.
The RHR however does not require nor does it authorize EPA to de-commission or shut down
facilities to achieve the goals of the rule.
EPA agrees with commenters who stated that renewable energy sources can be used in
place of coal-fired power plants. However, the RHR does not require that coal-firedfacilities use
or switch to renewable energy sources to meet the goals of the rule. The RHR establishes a five
step process EPA must follow when performing a case-by-case BART determination. In the first
90 Please see http://www.epa.sov/resion09/air/maps/maps tov.html for EPA Region 9 air quality designations.
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step, "Identification of all available retrofit technologies ", EPA does not consider BART as a
requirement to redesign a source (see 70 FR at 39164).
Comment:
Fifty-two private citizens (0085, 0086, 0087, 0088 , 0089, 0091, 0092, 0122, 0123, 0124,
0125, 0126, 0127, 0128, 0132, 0134, 0135, 0136, 0137, 0138, 0140, 0141, 0147, 0148, 0149,
0151, 0153, 0154, 0155, 0156, 0157, 0158, 0159, 0160, 0161, 0162, 0165, 0166, 0170, 0171,
0172, 0173, 0178, 0181, 0188, 0190, 0197, 0199, 0202, 0208, 0211, 0213, 0214) expressed
concern about the poor air quality in the Four Corners area. Forty of these commenters (0085,
0086, 0087, 0089, 0091, 0092, 0123, 0126, 0127, 0128, 0134, 0136, 0137, 0138, 0141, 0148 ,
0149, 0151, 0153, 0154, 0155, 0157, 0158, 0159, 0160, 0161, 0162, 0166, 0170, 0171, 0172,
0173, 0178, 0181, 0188, 0197, 0202, 0211, 0213, 0214) claimed that FCPP has diminished the
visual quality of their respective regions. The regions mentioned in the comments include
Bayfield, Cortez, Durango, La Plata City, Pagosa Springs, and Oxford, CO; Southwest CO;
Albuquerque, Farmington , Mancos, Pecos, and Shiprock, NM; Bluff, UT; and Class I areas such
as Arches, Chaco Canyon, Grand Canyon , Maroon Bells, Mancos Valley, Mesa Verde, Sleeping
Ute, and Wheeler Peak. One of these commenters (0172) disapproved of pollution coming from
Arizona affecting Colorado.
Five private citizens (0089, 0091, 0124, 0128, 0201) supported EPA's proposal to reduce
NOx emissions at FCPP. Two private citizens (0091, 0201) supported EPA's proposal to reduce
PM emissions at FCPP.
Response:
EPA acknowledges the comments and generally agrees with comments regarding
diminished visibility in the Four Corners Area. As detailed in our response to the previous
comment above, the air quality in the Four Corners area is meeting the national health-based
standards as set by EPA. EPA agrees with commenters that the NOx emission reductions
finalized will reduce visibility impairment in the numerous mandatory Class I Federal areas
surrounding FCPP.
As described in Section 8.2 of this RTC, EPA is not taking action at this time on our
proposal to set new PM limits for Units 13. If APS is unable to or decides against
implementing the alternative emission control strategy and continues operation of Units 1-3,
EPA will again conduct a five-factor analysis for PMfor Units 13 and propose another BART
determination for public comment.
Comment:
The Navajo Nation (0223) pointed out that as a federal agency, EPA has a trust
responsibility to the Navajo Nation that requires it to give special consideration to the Nation's
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best interests in any action.91 Because of the significant interest of the Navajo Nation in FCPP
(see related comments in Section 4.1), the commenter asserted that the BART proposal clearly
implicates the Nation's tribal trust interests. The commenter further contended that since EPA is
adopting a FIP for BART in lieu of a TIP by the Navajo Nation, the EPA is essentially "standing
in the shoes" of the Nation for purposes of making the BART determination and should,
therefore, defer to tribal views when making environmental policy decisions and give the same
weight to the BART factors that the Navajo Nation would in determining BART for FCPP; that
is, to the extent that the Nation recommends a particular control technology as BART for power
plants located on the Nation's lands, EPA should give substantial weight to that recommendation
as part of its decision-making process. (As discussed in Section 8.1, the commenter asserted that
advanced combustion controls, rather than SCR, properly represent BART for FCPP.) Thus, the
commenter stated that as the Nation's trustee and "stand-in" for the BART determination for
FCPP, the EPA should not select a more stringent BART than the commenter argued is required
by the RHR to achieve "reasonable progress" where doing so would likely have substantial
adverse impacts on the Navajo Nation. (See Section 4.1 for related comments on the potential
impacts identified by the commenter.)
The commenter (0223) also stated that EPA has a duty to undertake government-to-
government consultations with the Navajo Nation, and that EPA must coordinate with the
Navajo Nation in its relationship with, and reliance on, other federal agencies. The commenter
pointed out that EPA relies on data provided by the NPS, another federal trustee of the Nation,
but has not coordinated consultation between NPS and the Navajo Nation on this rulemaking.
The commenter indicated that the May 2011 EPA Tribal Policy recognizes that such
coordination is required under Executive Order 13175 and asserted that EPA should coordinate
consultation with the U.S. Forest Service (who provided data used in the proposed rulemaking)
as well as various DOI agencies that have an interest in this rulemaking, including NPS, the
Bureau of Indian Affairs, the U.S. Fish and Wildlife Service, the Office of Surface Mining
Reclamation and Enforcement, and potentially the Bureaus of Land Management and
Reclamation. The commenter added that consultation with Department of Energy (DOE) may be
important in regard to including FCPP in a study that DOE is proposing to carry out for NGS,
which also is located on the Navajo reservation and uses Navajo coal.
Response:
It is EPA's policy (EPA Policy on Consultation and Coordination with Indian Tribes,
May 4, 2011 (EPA Tribal Consultation Policy))92 to consult on a government-to-government
basis with federally recognized tribal governments when EPA actions and decisions may affect
tribal interests. Consultation is a process of meaningful communication and coordination
between EPA and tribal officials prior to EPA taking actions or implementing decisions that may
affect tribes. One of the primary goals of the EPA Tribal Policy is to fully implement both
91 To support this assertion, the commenter cited Executive Order 13175 (65 FR 67249, November 6, 2000; EPA
Policy on Consultation and Coordination with Indian Tribes, section IV "Guiding Principles," May 4, 2011 (EPA
Tribal Policy); and the 1984 EPA Indian Policy.
92 See "EPA Policy on Consultation and Coordination with Indian Tribes", May 4, 2011, in the docket for this final
rulemaking.
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Executive Order 1317593 and the 1984 Indian Policy, with the ultimate goal of assuring tribal
concerns and interests are considered whenever EPA's actions may affect tribes by
strengthening the consultation, coordination, and partnership between tribal governments and
EPA.
For this action, EPA consulted with the Navajo Nation in accordance with the Executive
Order and EPA 's Indian Policies on numerous occasions. A record of all consultations with
tribes is included in the docket for this final rulemaking.94 As stated in the 2011 EPA Tribal
Consultation Policy, as a process, consultation includes several methods of interaction that may
occur at different levels.95 EPA consulted with the Navajo Nation at various times throughout the
process at various levels of government, including in-person consultation meetings with the
President of the Navajo Nation on May 19, 2011 and June 13, 2012.
EPA acknowledges the significant interest of the Navajo Nation in FCPP. Based on a
request made by the Navajo Nation during our May 19, 2011, consultation meeting, EPA
examined potential adverse impacts to Navajo Nation if the owners of FCPP chose to implement
the alternative emission control strategy in lieu of BART. The results of this analysis were
discussed with President Shelly during a consultation meeting on July 13, 2012 and will be
provided to President Shelly by letter as a follow-up to our consultation.
EPA agrees that we are acting to implement the BART requirements for a facility located
on the Navajo Reservation in circumstances in which the Tribe has not applied, or been
approved, to administer the applicable CAA program. EPA is mindful of the Navajo Nation's
views and recommendations, particularly where there is a potential substantial adverse
economic impact to the Navajo Nation. We disagree however that the Agency must "defer to
tribal views when making environmental policy decisions EPA is carrying out the requirements
of the CAA and the Regional Haze Rule pursuant to our authority to implement these
requirements in the absence of an EPA-approved program. EPA notes that the CAA and the TAR
provide mechanisms for eligible Indian tribes to seek approval of tribal programs should they
wish to administer CAA requirements.
As we stated in our proposed rule, FCPP is one of the nation's largest emitters of N0X
(over 42,000 tons ofNOx in 2009), was built roughly four decades ago, and has not installed any
new N0X controls since the 1990's. FCPP is also located within 300 km of 16 Class I areas,
sometimes known as the Golden Circle of National Parks.96
For this action EPA carefully considered the unique location of FCPP with respect to
proximate Class I areas as well as its economic importance to Navajo Nation. We conducted a
detailed analysis of available emission control technologies against the five-factors specified in
the BART Guidelines. EPA also conducted extensive air modeling (included in the Supplemental
Proposal). Additionally, we have considered the numerous comments we received on our
93 See "Executive Order 13175 of November 6, 2000" in the docket for this final rulemaking.
94 See document "Timeline of all Tribal Consultations on BART.docx" in the docket for this final rulemaking.
95 See "EPA Policy on Consultation and Coordination with Indian Tribes", May 4, 2011, in the docket for this final
rulemaking.
96 See http://www.nps.gov/history/history/online_books/nava/adhi/adhi4e.htm.
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proposals. In making our final decision we have had to balance the findings of our analysis
along with the interests of various stakeholders, our unique government-to-government
relationship with tribes, and our responsibility to carry out the requirements of the CAA and
RHR to achieve reasonable progress towards visibility improvements.
This final FIP strikes a reasonable balance between reducing emissions to improve
visibility while allowing for the facility to implement those reductions in a manner that is
consistent with its continued operation and economic viability.
EPA has received information and comments from numerous federal agencies for this
rulemaking and considered these in our final decision (all information and comments are
included in the docket). However, EPA disagrees that we relied principally on data from the
National Park Service. EPA conducted our own cost and visibility analyses for FCPP. EPA
plans to coordinate with the Department of Interior in any future tribal consultations related to
BARTfor the two coal-firedfacilities located on the Navajo Nation.
EPA acknowledges that the Department of Interior has contracted with the National
Renewable Energy Lab (NREL) of the Department of Energy to examine renewable energy
options for the Navajo Generating Station, which is also located on the Navajo Nation and uses
coal from the Kay enta Mine, located on Navajo and Hopi land. Information on the NREL study
is available from DOI97and will be included in the docket for EPA's upcoming proposed
rulemaking for NGS.
Comment:
One private citizen (0163/0164/0216) asserted that the FCPP BART analysis should be
based on the use of bituminous coal (with heat content of 11,500 Btu/lb) at the plant, but FCPP
indicated that the plant uses sub-bituminous coal (with heat content of 8,880 or 8,776 Btu/lb).
Based on this point, the commenter asserted that FCPP needs to have the air models redone,
available technologies reselected, cost of control technology redone, energy control impacts
redone, economic control impacts redone, non-air quality control impacts redone, existing
controls reevaluated, useful life of FCCP re-evaluated, air visibility re-evaluated and anticipated
improvement of visibility re-evaluated.
Response:
EPA disagrees with the commenter. The classification of coal used at FCPP is only
relevant to the presumptive NOx limits established for EPA 's RHR regulations, which suggest
emission limits based on the coal classification and boiler type. 40 CFR Part 51, Appendix Y,
E.5. Table 1. EPA discussed the presumptive NOx limits for Units 3 - 598 at FCPP in terms of
both bituminous and sub-bituminous coal, however, EPA conducted a full five-factor analysis for
BART. Coal classification is not related to any aspect of the full five-factor BART analysis,
therefore, regardless of whether the coal burned at FCPP is sub-bituminous or bituminous,
97 http://www.doi.gov/navajo-gss/index.cfm
98 Presumptive limits apply only to EGUs greater than 200 MW in size. Units 1 and 2 are smaller than 200 MW,
therefore the presumptive limits do not apply to those units.
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EPA's five-factor analysis does not need to be redone and our BART determination does not
need to be re-evaluated.
As stated in the TSD the classification of coal used by FCPP has historically been sub-
bituminous;99 however, FCPP asserts that its coal has more characteristics of bituminous coal
than sub-bituminous coal, and should be classified as bituminous. Based on this categorization,
FCPP cites the presumptive limit for NOxfor bituminous coal of 0.39 Ib/MMBtu from a dry-
bottom wall fired boiler as its applicable presumptive BART limit for Unit 3. See 40 CFR Part.
51, Appendix Y, E.5. Table 1. The presumptive limit for NOx for sub-bituminous coal is 0.23
Ib/MMBtu. Id. Generally, the high volatile content of sub-bituminous coal is known to ease
burning and improve efficiency of combustion controls to reduce N0X, thus, the presumptive limit
for sub-bituminous coal is lower than for bituminous coal.
The presumptive limits are not binding requirements for BART, rather they are included
in the BART Guidelines as limits that most EGUs can meet through the use of current
combustion control technologies. However, the BART Guidelines further state that the reviewing
authority may determine that an alternative control level is appropriate based on the careful
consideration of the statutory factors. Because EPA made our BART determination based upon
our careful examination of the five factors rather than relying on the general presumptions set
forth in the BART Guidelines, it was not necessary for our analysis or purposes of this regulation
to determine whether the coal used by FCPP is bituminous or subbituminous.
With respect to the modeling of FCPP operations the type of coal burned and associated
heat content were not germane to the analysis. The model is not itself, nor does it rely upon, a
production cost model. The underlying costs of operation, including fuel quantity and heat
content, as they flow through the summary economic statistics, are not modified with respect to
the type of coal consumed.
Comment:
Three of the owners of FCPP (0168, 0174, 0176/0177), who argued that advanced
combustion controls constitute BART for NOx at FCPP, pointed out that SCR can be assessed as
a potential control option later, under the reasonable progress component of the regional haze
program. One of the commenters (0176/0177) provided background information about the
Regional Haze program and noted that the CAA and BART rules treat BART as a part of the
larger "reasonable progress" requirement. The commenter asserted that under the broader
visibility program, the advanced combustion controls proposed by the commenter as BART can
and should be deemed also to satisfy the reasonable progress milestone in the current planning
period. The commenter added that whether additional emission controls may be needed after the
application of this BART is a question that should be addressed in the larger context of the many
sources of regional haze impairment on the Colorado Plateau, including, for example, mobile
sources and prescribed and uncontrolled fires, as well as the ongoing regional planning efforts to
address haze in the Western states. The commenter suggested that SCR can be considered during
the next 10-year planning period (2018-2028) if it proves that additional emission reductions are
99 See Determination of Four Corners Coal Ranking, March 11, 2008 by Alan Papp. Docket ID: EPA-R09-OAR-
2010-0683-0056.
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needed to ensure reasonable progress. Another of the commenters (0168) stated that this
approach would achieve reasonable progress and have the following benefits: (1) reduce the
immediate financial burden on its customers, (2) allow time for greater certainty in terms of
potential carbon limits and customer demand, and (3) retain greater flexibility in future resource
decisions including the possibility of divestiture.
Response:
EPA disagrees with the commenter that advanced combustion controls constitute BART
for NOx at FCPP, and that therefore SCR should be assessed as a potential control option later,
under the reasonable progress component of the regional haze program. EPA also disagrees that
under the broader visibility program, the advanced combustion controls proposed by the
commenter as BART can and should be deemed also to satisfy the reasonable progress milestone
in the current planning period.
As detailed in the TSD, Unit 2 at FCPP experienced operational difficulties subsequent to
its 1999 retrofit with LNB. Additionally, as noted in the Andover Report100 there are operational
risks associated with LNB/OFA retrofits on the Units at FCPP. Finally, it is not clear that the
boilers APS cited as having achieved NOx emissions of 0.4 Ib/MMBtu or lower following retrofit
with LNB + OF A are indeed comparable to the units at FCPP. EPA therefore concluded that
LNB and LNB+OFA are not capable of achieving the level of NOx control neededfor BART.
Regarding the comment to address FCPP in a broader regional planning context, EPA
addressed this comment in Section 8.0. However, EPA further notes that the BART requirement
of the RHR applies to major stationary sources built within a limited timeframe that contribute to
visibility impairment at nearby Class I areas. EPA and state or local air agencies have other
regulatory mechanisms to address emissions from new stationary sources or mobile sources, and
EPA further notes that those sources need not be addressed under BART, or assessed in a five-
factor analysis for an individual facility.
Comment:
One of the owners of FCPP (0176/0177), a group of FCPP owners (0185), and a utility
industry association (0187) noted that the proposal preamble indicated that there is a visible
plume originating from FCPP Units 1-3 that has some visibility-impairing effect in the area,
and that EPA sought information on this secondary visible plume, its frequency and persistence,
and whether it affects or can be observed from any Class I area (citing 75 FR 64231-32). The
owner of FCPP (0176/0177) stated that the BART rules [40 CFR 51.308(d)] and CAA [section
169(a)(1)] address visibility in Class I areas, and added that the EPA does not have a "roving
commission" to address visibility impairments that occur outside Class I areas. The commenter
pointed out that although there is an "integral vista program" to protect views from within Class I
areas (citing 40 CFR 51.301), such integral vistas must be identified by a Federal Land Manager
according to specified criteria (citing 40 CFR 51.304), and only one such vista has been
identified (in Maine) (citing 40 CFR 81.437). On this basis, the commenter concluded that
100 See "TSD ref [104] Andover Report" in the docket for this rulemaking at: EPA-R09-OAR-2010-0683-0059.
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"EPA's attempt to justify additional regulation of [PM] emissions and opacity on the basis of a
purported association with alleged visibility impairment that EPA stated may result from [an
FCPP] 'plume' outside Class I areas is ill-considered and should be abandoned."
The utility industry association (0187) and group of FCPP owners (0185) stated that the
Regional Haze program cannot be used to address visibility impairment outside of a Class I area,
even if it is visible from such an area (citing CAA section 169A(a)(l), and that in the absence of
evidence that this plume exists and significantly affects visibility in a Class I area, there is no
basis for this aspect of the proposed rule. Another of the owners of FCPP (0174) simply asserted
that the Regional Haze program provides no authority to require additional PM controls based on
a "purported" plume generated by the units at FCPP.
The Navajo Nation (0223) stated that it is inappropriate for EPA to request comment on
the secondary visible plume without verifying the existence of the plume or characterizing the
nature, cost, and effects observed in Class I areas. This commenter included this argument in
justifying continued operation of venturi scrubbers with an emission limit of 0.03 lb/MMBtu and
a 20 percent opacity standard as PM BART for Units 1-3 (see Section 8.2).
Response:
EPA disagrees with the commenters that we were attempting to address visibility
impairments outside of a Class I area under BART or that EPA requested comment without
verifying the existence of the secondary plume. EPA specifically requested comment in our
proposed rule about whether the secondary visible plume (that EPA Region 9 staff observed in
New Mexico out as far as Aztec and Bloomfield en route to Farmington from Albuquerque ) can
be seen from Mesa Verde National Park, the closest Class I area to FCPP or any other Class I
area near FCPP. In the TSD, EPA discusses whether this secondary visible plume is related to
the poor control offine particulates by the venturi scrubbers. Although EPA did propose PM and
opacity limits, EPA also took comment on whether BART can be satisfied by allowing APS to
continue to operate its existing venturi scrubbers on Units 13.
Although EPA received numerous comments on visibility impairment and anticipated
improvement in the area from both our proposed rule and the supplemental proposed rule, EPA
did not receive any specific information regarding whether this secondary plume impacts
visibility in any Class I area near FCPP.
As described in Section 8.2 of this RTC, EPA is not taking action at this time on our
proposal to set new PM limits for Units 13. If APS is unable to or decides against
implementing the alternative emission control strategy and continues operation of Units 1-3,
EPA may again conduct a five-factor analysis for PMfor Units 13 and propose another BART
determination for public comment.
Comment:
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One public interest advocacy group (0112), the Navajo Nation (0223), and one
environmental advocacy group (0182) supported establishment of a 20 percent opacity limit for
material handling. The public interest advocacy group (0112.1) stated that the FCPP site is
subject to numerous dust-storm events originating in northwestern Arizona, and the additional
fugitive dust that could be picked up by these strong winds at the FCPP property added to the
incoming dust from the west makes breathing and outdoor activity miserable on from 4 to 12
days per year for residents of Montezuma County, CO and San Juan County, NM. The
commenter supports requiring FCPP to develop a dust control plan within 90 days of
promulgation of the final rule to be submitted to the EPA Regional Administrator and
implemented immediately. The commenter also asked that courtesy copies of the dust control
plan be submitted to appropriate local governments in the Four Corners area, such as the Navajo
Nation EPA, San Juan County (NM), and Montezuma, Dolores, and La Plata Counties (CO).
The Navajo Nation (0223) added that the fugitive dust plan should be reviewed
thoroughly and include appropriate recordkeeping and monitoring requirements. The commenter
also expressed support for the constructive approaches described in the supplemental proposal to
the management of dust, ash, and PM, stating that these approaches are practicable and will be
consistent with EPA's ongoing progress and rulemaking under the CAA for mercury, coal
combustion residues, GHGs, and other contaminants; improve the efficiency of Units 4 and 5;
and provide environmental and health co-benefits, which are essential for quality of life and
economic opportunities.
One of the owners of FCPP (0176/0177) noted that in addition to the proposed BART
requirements, EPA proposed separate fugitive dust control requirements and a 20 percent opacity
limitation for certain material handling operations, which are unrelated to the CAA visibility
program. The commenter laid out the history of EPA's past attempt to apply fugitive dust
controls to FCPP, pointing out that EPA included such requirements in the 2007 FIP for the plant
and the commenter sought judicial review of those requirements based on the absence of a
reasoned explanation. Arizona Public Service Co. v. EPA, 562 F.3d 1116 (10th Cir. 2009) ("APS
v. EPA "). The commenter added that upon EPA's motion, the court vacated and remanded the
fugitive dust requirements (citing APS v. EPA at 1121-22, 1131; the EPA Merits Brief at 53; and
75 FR 64232, Oct. 19, 2010).
The commenter argued that the proposed requirements are arbitrary and should not be
finalized because the facts upon which EPA relies are inadequate to support the conclusion that
fugitive dust control requirements are "necessary or appropriate" to protect air quality at FCPP.
The commenter's points are outlined below:
• The "necessary or appropriate" language in the TAR at 40 CFR §49.11(a) is limiting -
not all requirements that could potentially yield some air quality benefit are "necessary or
appropriate to protect air quality." The EPA has indicated in the past that this language is
intended to be limiting (citing the ,4 AY v. EPA EPA Merits Brief at 56, 60 and EPA's
NSR rules for Indian country at 71 FR 48696, 48714, August 21, 2006).
• Although the Administrative Procedures Act (APA) requires that there be some
intelligible principle or criteria to guide the Agency's decisions, the EPA has not
identified the criteria that guide its judgment as to which regulatory requirements are
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"necessary or appropriate" and which are not. Such exercises of standardless discretion
are arbitrary and capricious. Qwest Corp. v. FCC, 258 F.3d 1191, 1201-02 (10th Cir.
2001); Dithiocarbamate Task Force v. EPA, 98 F.3d 1394, 1402 (D.C. Cir. 1996). See
also Pennaco Energy, Inc. v. EPA, 692 F. Supp. 2d 1297, 1314 (D. Wyo. 2009). Without
identified criteria, EPA's proposed conclusion that fugitive dust controls are "necessary
or appropriate" is inevitably arbitrary.
• The reasons given in the proposal preamble for imposing fugitive dust requirements are
inadequate to support the proposed conclusions. In the end, EPA makes no effort to
identify a specific, concrete air quality problem that needs to be addressed or to quantify
FCPP's contribution to any such problem.
• Regulation of fugitive dust without a well-defined air quality basis would not only be
arbitrary in and of itself, but would also conflict with guidance the EPA has provided to
the states. This guidance includes (1) the 1986 document Identification, Assessment, and
Control of Fugitive Particulate Emissions (EPA/600/8-86/023, excerpt attached to the
comments as Exhibit H); (2) the 1977 memorandum Guidance on SIP Development and
New Source Review in Areas Impacted by Fugitive Dust (attached as Exhibit I); and (3)
the 1987 PMio SIP Development Guideline (attached as Exhibit J).101
• The EPA may not depart from its established policies without reasoned explanation.
Although EPA may argue that it is not expressly bound by its SIP policies in crafting a
FIP for Indian country, EPA cannot ignore those policies without expressing good reason
to do so. To avoid being arbitrary or capricious, a federal agency must treat like situations
alike and must follow its own established policies, in the absence of a well-reasoned basis
for doing otherwise. Transactive Corp. v. United States, 91 F.3d 232, 237 (D.C. Cir.
1996); Illinois State Chamber of Commerce v. EPA, 775 F.2d 1141, 1147 (7th Cir. 1985).
• The EPA has provided no explanation for its selection of the 20 percent opacity limit, as
opposed to no limit or a higher limit (citing 75 FR 64232). A rule without any stated basis
is necessarily arbitrary and capricious. Small Refiner Lead Phase-Down Task Force v.
EPA, 705 F.2d 506, 551 (D.C. Cir. 1983). See also, Appalachian Power Co. v. EPA, 135
F.3d 791, 818 (D.C. Cir. 1998). See NortheastMd. Waste Disp. Auth. v. EPA, 358 F.3d
936, 948 (D.C. Cir. 2004); Columbia Falls Aluminum Co. v. EPA, 139 F.3d 914, 923
(D.C. Cir. 1998); American Maritime Ass 'n v. United States, 766 F.2d 545, 566 n. 30
(D.C. Cir. 1985).
• Opacity limits for fugitive dust in SIPs and TIPs appear to be widely varied, as shown in
the 1983 document Opacity Regulations: Summary of State Regulations and Rulemaking
Status (attached as Exhibit M with summary tables reproduced in the comments). Data
from a 2007 study by UARG show a variety of opacity limits for coal handling activities
in recent PSD permits for new coal-fired plants (excerpt attached as Exhibit N). The
NSPS 20 percent opacity standard in 40 CFR part 60, subpart Y cannot properly be the
basis for the FCPP opacity limit because Congress intended that, in general, existing
sources such as FCPP would be subject to less stringent standards than new sources built
after the applicability dates of the various NSPS. California v. Department of the Navy,
101 The Exhibits referenced by commenter 0176/0177 are attached as embedded PDF files to the comment letter in
the docket for this rulemaking, atEPA-R09-OAR-2010-0683-0177 orEPA-R09-OAR-2010-0683-0176.
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431 F. Supp. 1271, 1291 (N.D. Cal. 1977), qff'd, 624 F.2d 885 (9th Cir. 1980). See S.
Rep. No. 1196, 91st Cong., 2d Sess. 15-16 (1970); Arbuckle, etal., Environmental Law
Handbook (Twelfth ed. 1993) at 127.
Another of the owners of FCPP (0168) expressed general support for the points made by
Commenter 0176/0177.
Response:
EPA acknowledges support for establishing a 20% opacity limit for material handling
and a Dust Control Plan at FCPP. For the reasons outlined below, EPA has finalized both these
requirements. EPA notes that the Dust Control Plan shall include a description of the dust
suppression methods for controlling dust from site activities including coal handling and storage
facilities, ash handling, storage, and landfills, and road sweeping activities. The 20% Opacity
standard will apply to any crusher, grinding mill, screening operation, belt conveyor, or truck
loading or unloading operation.102
As mentioned in an earlier response to this RTC, EPA notes that on June 21, 2010, EPA
proposed and solicited comments on two regulatory options for establishing national standards
for management of CCW (75 FR 35127). The proposal includes options for fugitive dust controls
that would apply to FCPP when finalized.
EPA agrees with the commenter that the fugitive dust plan should be reviewed and should
include appropriate recordkeeping and monitoring requirements. EPA intends to review the Dust
Control Plan prior to approval for use.
EPA agrees with the commenter that the fugitive dust and 20% opacity limit are
unrelated to the CAA visibility program. EPA also agrees with the history laid out by the
commenter on fugitive dust controls at FCPP. EPA included these dust control requirements in
the previous FIP finalized in 2007 because EPA considered them necessary or appropriate
under the TAR to assure that the dust from this facility does not adversely contribute to possible
violations of the NAAQS for PM10. Most large coal fired power plants are either covered by a
State's general opacity limit (generally set at 20%), a specific limit in its permit or the NSPS
Standards for coal handling (NSPS Subpart Y). APS is correct that EPA withdrew the 2007 FIP
requirements on dust when APS appealed the rule. EPA had not adequately documented in the
recordfor the 2007 FIP our basis for establishing the 20% opacity regulation. For the 2007
FIP, EPA chose not to defend our position based on the record for that rulemaking and instead
chose to address the issue in a subsequent FIP action, such as this one.
EPA disagrees with the commenter that the fugitive dust and opacity requirements are
arbitrary or that our argument is inadequate to support our conclusion that fugitive dust control
requirements are necessary or appropriate to protect air quality at FCPP. EPA first
promulgated dust control requirements for new coal handling equipment on January 15, 1976
102 Submittals received by EPA as a result of these requirements may be requested by the public via a Freedom of
Information Act request unless claimed as Confidential Business Information (CBI) by the author of the document
and determined to meet the CBI regulations at 40 CFR part 2 by EPA
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(41FR 2232). This rule affected equipment constructed or modified after the 1970s that affected
facilities built or modified after October 24, 1974. The purpose of these New Source
Performance Standards (NSPS) was:
NSPS implement CAA section 111(b) and are issuedfor
categories of sources which have been identified as
causing, or contributing significantly to, air pollution
which may reasonably be anticipated to endanger public
health or welfare. The primary purpose of the
NSPS are to help States attain and maintain ambient air
quality by ensuring that the best demonstrated emission
control technologies are installed as the industrial
infrastructure is modernized.
See 74 FR 51951 (October 8, 2009).
EPA's basis for finding that it is necessary or appropriate for FCPP to comply with a
requirement to limit its material handling emissions to 20% or less is being set forth in this
rulemaking. EPA has promulgated a 20 percent opacity limit for all new coal handling
operations built after the mid 1970s in the New Source Performance Standards. This NSPS
standard applied to any coal handling equipment processing more than 200 tons per day of coal.
Because FCPP receives approximately 10 million tons of coal per year for combusting in Units
1-5, it may be processing more than 27,000 tons of coal per day. This is more than 100 times the
smallest size coal handling operation subject to the NSPS, and which EPA considered necessary
for protecting public health and welfare. As mentioned before, FCPP's massive quantity of coal
moves by conveyor belt across FCPP's property line, passing through numerous transfer points
before the coal is loaded into the storage silos that feed the individual pulverizers and
combustion units. Each of these transfer points along with the conveyor belts has the potential
for PM emissions. The PM can be minimized by collection devices or dust suppression
techniques such as covered conveyors or spraying devices at the transfer points.
FCPP and the BHP Navajo Mine that provides FCPP's coal are within close proximity
to Morgan Lake which is a recreational lake with public access just beyond the FCPP's property
line. Excess dust can blow over the FCPP property line to Morgan Lake and adjacent
properties. EPA has received complaints from Navajo Tribal members concerning excess dust
emissions generatedfrom the ash landfill FCPP maintains, as well as from the other material
handling and storage operations.
EPA concludes that it is necessary or appropriate to set enforceable fugitive dust/PM
suppression measures to protect ambient air quality because (1) there is a large potential for
dust emissions from the facility coal and ash operations to be emitted and blow across the
property line, (2) EPA has received numerous complaints concerning excess dust from the ash
landfill and other operations, and (3) these activities are occurring in close proximity to a public
access area.
EPA disagrees with the commenter that the 20percent opacity limit is arbitrary and
capricious. While EPA acknowledges that New Mexico does not have a general opacity limit that
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applies to dust, the other three Four Corners States do. In Arizona and Colorado a general 20
percent opacity limit applies at all facilities including "grandfathered" coal fired EGUs. In Utah
the general opacity limit for facilities built before the CAA in 1971 are subject to a 40 percent
opacity limit. However, all of Utah's large coal-fired EGUs were constructed after 1971 and are
subject to a 20 percent general opacity limit, i.e., the NSPS. Therefore, ifFCPP had been built a
few years later or a few miles in a different direction, it would be subject to the NSPS or a SIP
provision limiting its coal material handling and storage operations to 20 percent opacity.
Because FCPP is located on the Navajo Nation where generally applicable limits that
often are included in SIPs do not exist and because it was constructed nearly 40 years ago, and
because dust control measures at coal fired power plants are important for maintaining the PMw
NAAQS in the areas adjacent to the power plant properties, EPA finds that it is necessary or
appropriate to impose measures to limit the amount of PM emissions from these material
handling and storage emission sources. EPA recently imposed similar dust control requirements
at the Navajo Generating Station, which is also on the Navajo Nation. 75 FR 10174.
Comment:
One environmental advocacy group (0182) noted that the owners of FCPP Units 4 and 5,
or their governing utility commissions, may determine that it is more prudent to cease coal-fired
operations than to install the emissions controls required to operate the units indefinitely. The
commenter suggested that the EPA should include alternative language in the FIP that would
accommodate cessation at or within the 5-year deadline for compliance with BART or, should
the EPA require compliance with emission limits at an earlier date as the commenter
recommended, the shutdown scenario should be tied to the date on which BART compliance is
required. The commenter pointed out that Oregon has proposed a Regional Haze Plan including
such multiple options, giving the plants and their governing commissions the flexibility to select
the most economically and environmentally sound option (citing the Oregon plan which was
included with the comments as an attachment).
Response:
EPA disagrees with the commenter. The owners of FCPP Units 4 and 5 did not suggest in
its alternative to BART proposal any scenario that would include shut down of Units 4 or 5.
Unless the owners of FCPP suggest the closure of Units 4 and 5 as an alternative to BART, EPA
does not have the authority to consider this as another option. At any time, the owners have the
choice to shutdown entirely by the BART compliance timeframe in lieu of installing BART. In the
final rule EPA has finalized both BART and the alternative to BART (which would include shut
down of Units 1-3) and given the owners of FCPP the choice of which option to implement.
Comment:
One environmental advocacy group (0184) stated that the EPA must consult in
accordance with sections 7(a)(1) and 7(a)(2) of the Endangered Species Act (ESA) with regards
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to the proposed FIP because of the impacts of FCPP on threatened and endangered fish, wildlife,
and plants and their designated critical habitats, which the commenter discussed at some length.
The commenter added that EPA has discretion under the TAR to limit emissions of mercury,
selenium, and other pollutants that may adversely affect the razorback sucker and Colorado
pikeminnow, and these species' critical habitats. According to the commenter, this discretion is
part of what triggers the Agency's obligation to consult pursuant to sections 7(a)(1) and 7(a)(2)
of the ESA.
Response:
EPA disagrees with the commenter that determining BART and promulgating this FIP for
FCPP necessitates ESA Section 7 consultation. EPA understands that the US Fish and Wildlife
Service (FWS) is primarily concerned about the effects of mercury and selenium on endangered
fish species in the San Juan River. EPA notes that under the BART Alternative, mercury and
selenium emissions will be reducedfrom FCPP due to the closure of Units 13. Additionally,
EPA 's national MATS rule set new emission limits for mercury that would apply to Units 1 - 3 at
FCPP if those units are not closed. EPA further notes that the goal of the Regional Haze Rule is
to control emissions of visibility-impairing pollutants in order to restore visibility to natural
conditions at the mandatory Federal Class I areas, and mercury and selenium do not affect
visibility. Therefore, EPA does not have authority to regulate emissions of mercury or selenium
under BART.
Comment:
The coal supplier for FCCP (0117) questioned the legality of EPA's approach to the
Regional Haze program at FCPP. According to the commenter, EPA's BART and better-than-
BART proposals are not authorized because BART is not "reasonably separable" from the
remainder of a regional haze implementation plan for the Navajo Nation under the TAR. The
commenter went on to question EPA's entire approach to the Regional Haze program, which the
commenter asserted impermissibly isolates BART from the context of the overall reasonable
progress goal in violation of the CAA. After a lengthy discussion, the commenter concluded that
the minimum amount of reasonable progress that BART needs to achieve in a given Class I area
cannot be determined until the amount of reasonable progress achieved by other CAA and state
programs is subtracted from that area's reasonable progress goal. The commenter asserted that
EPA's determination of BART for FCPP is fatally flawed because that determination has failed
to consider not only the reasonable progress goals for affected Class I areas but also the amounts
of reasonable progress that will be achieved in those areas by other non-regional-haze programs.
The commenter stated that EPA has not determined BART for FCPP in accordance with the law,
and thus the Agency's proposed BART for FCPP should be withdrawn. For similar reasons, the
commenter alleged that the NOx emission reductions that would be achieved under the
supplemental proposal are in excess of the amount required to achieve the reasonable progress
goals in the area.
The commenter (0117) added that EPA must consider the reasonable progress already
achieved by past FCPP emission reductions. The commenter stated that until the 2007 FIP
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became effective, emissions from FCPP were not subject to any enforceable limits, and that
FCPP's uncontrolled S02, NOx, and PM emission rates should perhaps serve as the baseline for
determining the visibility improvements resulting from that FIP. The commenter argued that
these visibility improvements would almost certainly satisfy the reasonable progress goals of
many Class I areas for the first planning period, and that significant portions of the areas'
progress goals have likely been achieved by the "additional" S02 reductions provided by the
2007 SIP. The commenter concluded that any necessary reasonable progress remaining to be
achieved by NOx BART at FCPP cannot be determined until the reasonable progress achieved by
prior emissions reductions at FCPP is considered.
In this context, the commenter (0117) stated that EPA's BART determination did not
properly weigh the statutory factors. The commenter stated that it does not appear that EPA's
selection of BART has been influenced by any meaningful consideration of the statutory factors
(citing EPA's rationale at 75 FR 64230). Specifically, the commenter indicated that individual
Class I area visibility improvements from SCR have not been compared with respect to the
statutory factors to visibility improvements from LNB, and the actual amounts of those
improvements have not been measured against the amounts of improvements needed to meet
reasonable progress goals. The commenter also stated that cost effectiveness metric used by EPA
(i.e., $/ton of NOx reduced) does not satisfy the statutory requirement to consider the cost to
comply with the Regional Haze program; that is, because EPA's determination of BART for
FCPP has not considered the true costs of compliance with the statutory requirement to make
reasonable progress, the determination is fatally flawed and should be withdrawn. Finally, the
commenter discussed the "remaining useful life" statutory factor, noting that under the BART
Guidelines remaining useful life is ignored in the majority of BART determinations (citing
40 CFR part 51, Appendix Y, section IV.D.4.k), which the commenter asserted is inappropriate.
According to the commenter, Congress designated the remaining useful life of the source as an
important consideration because it did not want to impose the burdens of control technology
retrofits on sources that were more than 15 years old at the time the statute was enacted. Given
that it is now 34 years after the BART requirements were enacted, the commenter argued that the
"remaining useful life" statutory factor should weigh heavily in BART determinations for older
sources such as FCPP, instead of being ignored.
In summing up these comments, the commenter (0117) stated that EPA's proposed
BART determination and "better-than-BART" determination for FCPP are substantially flawed.
According to the commenter, these determinations fail to implement fundamental statutory and
regulatory concepts and instead rely on EPA's "inappropriate, incorrect, illogical, and/or
unlawful" guidance, and fail to properly consider and weigh several of the five statutory factors
for determining BART. As a result, the commenter stated that EPA should consider withdrawing
both proposals and begin anew in a manner that avoids the major flaws and deficiencies within
the current proposals.
Response:
EPA disagrees with the commenter who questioned the legality of our approach and that
stated that EPA 's BART and "better than BART" proposals are not authorized because BART is
not "reasonably separable "from the remainder of a regional haze implementation plan for the
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Navajo Nation under the TAR. We also disagree that our approach to the Regional Haze
program impermissibly isolates BART from the context of the overall reasonable progress goal
in violation of the CAA, and that our proposed BARTfor FCPP should be withdrawn.
EPA's authority to promulgate a source-specific FIP in Indian County is based on CAA
sections 301(a) and (d)(4) and the regulations implementing these provisions known as the TAR
at 40 CFR Part 49. CAA section 301(d)(4) provides EPA with broad discretion to promulgate
regulations directly for sources located in Indian country103, including on Indian reservations if
we determine such Federal regulations are ' 'necessary or appropriate'' and the Tribe has not
promulgated a TIP. Specifically, in 40 CFR 49.11, EPA interpreted CAA section 301(d)(4) to
authorize EPA to promulgate ' 'such Federal implementation plan provisions as are necessary or
appropriate to protect air quality''. As such, because the Navajo Nation has not implemented a
TIP for Regional Haze, EPA interprets the TAR to provide discretion to EPA to determine which
requirements of the RHR are necessary or appropriate to protect air quality, and to promulgate
just those implementation plan provisions accordingly. Because two stationary sources on the
Navajo Nation meet the BART eligibility criteria, EPA has determined that it is necessary or
appropriate at this time to evaluate source-specific FIPs to implement the BART requirement of
the RHR for each BART-eligible facility located on the Navajo Nation. The basis for our
determination is discussed in several prior responses (See, e.g., Sections 2.1, 4.1.2, and 8.1).
The Courts have agreed with EPA that it may implement requirements that are necessary or
appropriate without providing for all aspects of the CAA programs. See Arizona Public Service
v. EPA 562 F. 3d 1116 (10th Cir. 2009).
EPA disagrees with the comment that BART must be established in relation to reasonable
progress goals. State or Tribal Implementation Plans for Regional Haze must establish goals
that provide for reasonable progress towards achieving natural visibility conditions for each
mandatory Class I Federal area located within its borders (40 CFR 51.308 (d)(1). The FCPP
and the NGS are both located within the Navajo Nation Indian Reservation, and for the reasons
outlined above, EPA is conducting BART determinations for each facility. There are no
mandatory Class I Federal areas as designated by Congress located within the Navajo
Nation.104 EPA further notes that the five-factor analysis outlined in the BART Guidelines,
which were promulgated as a notice and comment rulemaking, does not require consideration of
reasonable progress goals in determining BARTfor a given facility.
EPA also disagrees with the comment that our cost effectiveness analysis should be
withdrawn because it did not satisfy statutory requirements. EPA notes that there is no
regulatory or statutory requirement to consider the cost to comply with the Regional Haze
103
"Indian country" is defined under 18 U.S.C. 1151 as: (1) All land within the limits of any Indian reservation
under the jurisdiction of the United States Government, notwithstanding the issuance of any patent, and including
rights-of-way running through the reservation, (2) all dependent Indian communities within the borders of the
United States, whether within the original or subsequently acquired territory thereof, and whether within or without
the limits of a State, and (3) all Indian allotments, the Indian titles to which have not been extinguished, including
rights-of-way running through the same. Under this definition, EPA treats as reservations trust lands validly set
aside for the use of a Tribe even if the trust lands have not been formally designated as a reservation.
104 EPA notes that Navajo Nation has established its own parks and monuments, including Monument Valley,
Canyon de Chelly, and the Four Corners Monument, however, these parks are not mandatory Class I Federal Areas
as set by Congress.
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Program as a whole within an individual five-factor BART analysis. Because the Regional Haze
Program requires review every ten years, it is impractical in a BART analysis (which occurs
during the first Regional Haze planning period) to anticipate and consider the costs of undefined
requirements in all future planning periods.
EPA also disagrees that the minimum amount of reasonable progress that BART needs to
achieve in a given Class I area cannot be determined until the amount of reasonable progress
achieved by other CAA and state programs is subtractedfrom that area's reasonable progress
goal. Neither the CAA nor Regional Haze regulations set any quantitative presumptive targets
for the amount of reasonable progress that must be achieved. Rather, the regulations allow for
flexibility in determining the amount of reasonable progress towards the ultimate goal of
returning to natural background conditions.
EPA disagrees with the commenter that EPA must consider the reasonable progress
already achieved by past FCPP emission reductions and that previously uncontrolled SO 2, N0X,
and PM emission rates prior to previous FIPs for FCPP should serve as the baseline for
measuring visibility improvements. In its own five factor BART analysis, APS used actual N0X
emissions from 2001 - 2003 as baseline emissions for determining visibility improvement from
N0X controls. N0X emissions from 2001 - 2003 were generally consistent with and
representative ofNOx emissions over the past ten years.105 EPA agrees with APS in its use of
actual emissions over a recent time frame, rather than attempting to rely on previously
uncontrolled emissions emission rates from FCPP as a baseline.
Additionally, nothing in the BART regulations or guidance requires that EPA consider
past emission reductions in determining BART under the RHR However, as part of the required
five factor analysis for BART EPA did evaluate and consider the current pollution control
equipment in use at FCPP.
EPA disagrees with the comment that EPA 's BART determination did not properly weigh
the statutory factors. As discussed elsewhere in this document, the BART Guidelines allow the
reviewing authority (State, Tribe, or EPA) the discretion to determine how to weigh and in what
order to evaluate the statutory factors (cost of compliance, the energy and non air quality
environmental impacts of compliance, any existing pollution control technology in use at the
source, the remaining useful life of the source, and the degree of improvement in visibility which
may reasonably be anticipated to result from the use of such technology), as long as the
reviewing authority justifies its selection of the "best" level of control and explains the CAA
factors that led the reviewing authority to choose that option over other control levels (see 70 FR
39170, July 6, 2005). EPA provided a detailedjustification for our BART evaluation process and
five factor analysis in the TSD for our proposed BART determination. This justification has been
discussed in more detail in prior responses to comments (see, e.g., Sections 6.0 and 8.1)
EPA also disagrees with the comment that individual Class I area visibility improvements
from SCR have not been compared with respect to the statutory factors to visibility improvements
from LNB. In the preamble to our October 19, 2010 proposed BART determination and in the
105 As seen in Table 3 below, NOx emissions in 2001 and 2003 were highest over the 10 year period, but generally
consistent with emissions over the past 10 years.
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accompanying TSD, EPA compared the anticipated visibility improvement from SCR with the
anticipated improvement from combustion controls (LNB or LNB+OFA) (See 75 FR 64230,
Table 3, and TSD Tables 36 - 39), and noted that EPA modeled the visibility improvement from
SCR to far exceed the modeled improvement from combustion controls. As discussed elsewhere
in this document (see Section 3.0), commenters and EPA both calculated the incremental cost
between SCR and combustion controls, and the incremental cost of SCR is reasonable and does
not warrant eliminating SCR as the top BART option. In the TSD for our proposed BART
determination, EPA also compared the non-air quality environmental impacts of LNB and SCR
in the discussion on potential effects of both controls to the salability of fly ash. Because EPA
determined, based on an affordability analysis, that SCR should not force FCPP to close because
it could still generate electricity at lower cost than to purchase power on the open market, a
comparison of the effect of LNB and SCR on the remaining useful life of the facility is not
necessary. Additionally, without a firm commitment from the facility owner to close before the
end of the 20-year amortization period, it is inappropriate to consider a shorter useful life in the
five-factor analysis.
EPA disagrees with the commenter that we ignored the "remaining useful life " statutory
factor in our BART decision. EPA considered this factor in our BART analysis (see pages 42-43
of the TSD). As discussed in the TSD and in responses to comments within this document, the
remaining useful life of an EGU subject to BART is determined by the utility. EPA cannot
arbitrarily decide that an EGU has less useful life when it is not within our BART rulemaking
authority to require closure of an EGU. If a utility solicited a shorter useful life than one that
would allow the full amortization of any necessary pollution controls, EPA would take that into
account in the cost analysis, provided that there was assurance the EGU would cease operation
by that time.
Comment:
In virtually identical comments that addressed both FCPP and NGS submitted prior to the
supplemental proposal, one public interest advocacy group (0094) and one environmental
advocacy group (0146) requested that EPA assert maximum responsibility to oversee the TAR
for promulgating oversight of FCPP and NGS on the Navajo Nation.
Response:
EPA agrees with commenters that we have a responsibility under the TAR for oversight
of FCPP and NGS. We are exercising our authority under the TAR to implement these BART
provisions at FCPP as necessary or appropriate to protect air quality in Indian country.
Comment:
One private citizen (0131) asserted that the BART proposals for FCPP and SJGS unfairly
subject SJGS to greater controls than FCPP for political reasons specifically that EPA seems to
be favoring FCPP because of a potentially large local block of voters for 2012. The commenter
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stated that EPA needs to wait until FCPP is cleaned up before taking any further action on SJGS.
The commenter asserted that SJGS is probably being blamed for haze caused by FCPP.
Response:
EPA disagrees with this comment. EPA Regions IXand VI developedfive-factor BART
analyses for FCPP and SJGS independently following the established BART Guidelines with
absolutely no political considerations. EPA Region 9 notes that the BART determinations for
FCPP and SJGS both require the installation and operation of SCR, the most stringent NOx
control option, on all units no later than 5 years from the effective date of the final rule. Region 9
is finalizing both our BART determination for FCPP, as well as the alternative emission control
strategy. If the owners of SJGS had proposed to Region 6 an alternative to BART, Region 6
would also have given serious consideration to the merits of that alternative. Region 9 also notes
that the boiler configurations and existing air pollution control equipment at FCPP and SJGS
are different, resulting in the different numerical emission limits set as BART. However, as
discussed elsewhere in this RTC, the numerical emission limits result in comparable NOx
reduction efficiencies at FCPP and SJGS (80% reduction at FCPP versus. 83% at SJGS).
EPA also disagrees with the commenter that EPA should wait until FCPP is cleaned up
before taking action on SJGS because SJGS is probably being blamed for haze caused by FCPP.
The RHR and BART Guidelines do not limit BART determinations for different facilities located
in close proximity to each other from occurring simultaneously, and if FCPP and SJGS were
both located in the state of New Mexico, the BART determinations would have been made
concurrently. Additionally, visibility modeling conductedfor each facility alone and based on the
specific emissions from that given facility, showed that SJGS and FCPP each contribute to
visibility impairment at 16 nearby Class I areas.
Comment:
One private citizen (0151) supported the EPA Region 6's proposal to implement retrofit
technology at the San Juan Generating Station (SJGS). Another private citizen (0209) supported
imposing maximum restrictions on both the FCPP and the San Juan Generating Station. A third
private citizen (0210) supported the comments submitted by Senator Bennet of Colorado on
cleaning up SJGS.
Response:
EPA thanks commenters for submitting comments on Region 6's BART determination for
SJGS to the docket for the BART determination for FCPP proposed by Region 9. Region 9
provided comments we received on SJGS to Region 6. EPA agrees that reducing emissions at
both power plants will result in improvements in both visibility and air quality in the Four
Corners area.
Comment:
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While acknowledging that FCPP emits significant amounts of air pollutants, the Navajo
Nation (0223) pointed out that EPA's statement that FCPP is the largest emitter of NOx in the
United States is based on gross emissions measured in tons per year. According to the
commenter, it would be more meaningful to consider emissions in the context of the size of
FCPP and the energy produced, measured in pounds per MMBtu, compared with other plants
burning coal. The commenter stated that EPA should compile, and make available to the public,
information that would allow a fair and accurate assessment of emissions from FCCP compared
to those from other coal-fired plants.
Response:
EPA agrees with the commenter that expressing emissions in pounds per MMBtu
(Ib/MMBtu) provides additional information and changes the relative "ranking" of FCPP
against other coal-fired power plants, but disagrees with the commenter that Ib/MMBtu is more
meaningful for two reasons:
(1) The goal of the BART requirement of the Regional Haze Program is to reduce the
visibility impact of air pollution emissions from certain stationary sources on nearby Class I
areas. From this perspective, the total mass of visibility-impairing pollutants emittedfrom the
stationary source is most meaningful. If the goal of the program was to improve the efficiency of
the power plant, then evaluating emissions on a Ib/MMBtu basis would be more meaningful than
a total mass basis.
(2) Evaluating "rankings" based on Ib/MMBtu ignores how often the facility operates
and how large the facility is, both of which affect the annual mass emissions ofpollutants into
the atmosphere. For example, in 2001,106 when FCPP was ranked #3 in terms of total tons of
NOx emitted, FCPP was ranked #97 in terms of pounds ofNOxper MMBtu heat input. The top
two facilities in terms of Ib/MMBtu in 2001 emitted NOx at rates of 1.7 and 1.4 Ib/MMBtu, but
only operated 3 and 6 months that year, and each emitted less than 200 tons ofNOx, compared
to the 47,000 tons ofNOx emitted by FCPP. Similarly, in 2011,107 when FCPP was the highest
NOx emitter in the nation, FCPP was ranked #23 in terms of Ib/MMBtu. The highest NOx emitter
in terms of Ib/MMBtu in 2011 was a facility that emitted NOx at a rate of 1.9 Ib/MMBtu, but only
emitted 146 tons ofNOx that year, compared to the 39,000 tons ofNOx emitted by FCPP.
Another way to evaluate the NOx data, is to first sort facilities by heat input before
examining ranking based on Ib/MMBtu. In 2001, FCPP was the 14th largest power plant in terms
of heat input. Compared to the 13 other facilities with greater heat input, FCPP emitted NOx at
the highest rate (0.56 Ib/MMBtu), with emission rates of the 13 other facilities ranging from 0.16
- 0.54 Ib/MMBtu. This shows that all larger (heat input) power plants, in 2001, achieved lower
Ib/MMBtu NOx emission rates than FCPP. In 2001, the best performing facility that was larger
(heat input) than FCPP that was the WA Parish power plant in Texas, which operates four
106 See spreadsheet titled "2001 CAMD.xls" in the docket for this final rulemaking
107 Data reported for 2011 are preliminary data available from CAMD. See spreadsheet titled "2011 and 2012
prelim CAMD.xlsx" in the docket for this final rulemaking.
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natural gas-fired units andfour coal-fired units. The emission rate reported in Table 3
represents coal-fired units only.108
In 2011, FCPP was the 21st largest power plant in the nation in terms of heat input.
Compared to the 20 other facilities with greater heat input, FCPP again emitted N0X at the
highest rate (0.55 lb MMHtu). with emission rates of other larger facilities ranging from 0.01 to
0.24 lb MMHtu. Of the largest facilities, the facility achieving 0.01 lb MMHtu was a natural gas-
fired combined cycle facility (West County Energy Center in Florida), therefore,EPA did not
include this facility in Table 3. The second best performer of the 20 largest facilities was the
John E. Amos power plant in West Virginia, a coal-fired power plant emitting NOx at a rate of
0.05 lb MMHtu.
Between 2001 to 2011 (see Table 3 below),109 the range ofNOx emission rates from the
largest coal-fired power plants in the nation declined, going from a range of 0.16 - 0.54
lb MMHtu to 0.05 - 0.24 lb MMHtu. whereas the FCPP N0X emission rate over 2001 to 2011
showed little change. This suggests FCPP has not kept pace with the other largest coal-fired
power plants in the nation in terms of reducing its lb MMHtu N0X emission rate.
In this final rulemaking, EPA is requiring FCPP to meet a facility-wide N0X emission
limit of either 0.11 lb MMHtu as BART, or for Unit 4 and 5 to each meet a N0X emission limit of
0.098 lb MMHtu under the BART Alternative. This final rulemaking will allow FCPP to keep
pace with the largest coal-fired power plants in the nation in terms of reducing emissions ofNOx.
Table 3: Ranking of FCPP from 2001 - 2012 Based on 3 Metrics
Year
Total NOx Mass
NOx rate
Heat Input
NOx range of larger heat
(tons)
(lb/MMBtu)
(million MMBtu)
input coal-fired power plants
(lb/MMbtu)
2001
#3 (47,000)
# 97 (0.56)
# 14 (168)
0.15-0.54
2002
#8 (42,000)
#75 (0.57)
#26 (146)
0.16-0.59
2003
#3 (45,000)
#57 (0.57)
#18 (159)
0.11-0.53
2004
#1 (41,000)
#43 (0.55)
#23 (147)
0.04-0.47
2005
#1 (42,000)
#48 (0.53)
#21 (156)
0.05 - 0.46
2006
#1(45,000)
#40 (0.56)
#18 (160)
0.05-0.41
2007
#2 (41,000)
#37 (0.56)
#23 (147)
0.05 - 0.46
2008
#2 (40,000)
#29 (0.55)
#25 (146)
0.04-0.46
2009
#1(43,000)
#28 (0.54)
#16 (157)
0.05-0.33
2010
#1 (39,000)
#20 (0.55)
#23 (140)
0.05 - 0.28
2011
#1 (39,000)
#22 (0.55)
#21 (141)
0.05 - 0.24
2012
dst Q)
#1 (9,700)
#14 (0.54)
#12(36)
0.08-0.24
1118 However, the natural-gas fired units at WA Parish do not have a significant effect in dramatically reducing the
total facility NOx emission rate because those units are operated at a low capacity factor, e.g., see tab entitled "WA
Parish only" in the spreadsheet "2001 CAMD.xls".
109 See spreadsheets titled "2002 CAMD.xls", "2003 CAMD.xls", "2004 CAMD.xls", "2005 CAMD.xls", "2006
CAMD.xls", "2007 CAMD.xls", "2008 CAMD.xls", "2009 CAMD.xls", and "2010 CAMD.xls" in the docket for
this final rulemaking.
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