[Federal Register Volume 80, Number 61 (Tuesday, March 31, 2015)]
[Proposed Rules]
[Pages 17010-17020]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-07233]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 52
[EPA-R09-OAR-2015-0165; FRL-9925-31-Region 9]
Promulgation of Air Quality Implementation Plans; Arizona;
Regional Haze Federal Implementation Plan; Reconsideration
AGENCY: Environmental Protection Agency.
ACTION: Proposed rule.
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SUMMARY: The Environmental Protection Agency (EPA) is proposing to
revise part of the Arizona Regional Haze (RH) Federal Implementation
Plan (FIP) applicable to the Coronado Generating Station (Coronado). In
response to a petition for reconsideration from the Salt River Project
Agricultural Improvement and Power District (SRP), the owner/operator
of Coronado, we are proposing to replace a plant-wide compliance method
with a unit-specific compliance method for determining compliance with
the best available retrofit technology (BART) emission limits for
nitrogen oxides (NOX) from Units 1 and 2 at Coronado. While
the plant-wide limit for the NOX emissions from Units 1 and
2 were established as 0.065 lb/MMBtu, we are proposing a unit-specific
limit of 0.065 lb/MMBtu for Unit 1 and 0.080 lb/MMBtu for Unit 2. In
addition, we are proposing to revise the work practice standard in the
FIP for Coronado. Finally, we are proposing to remove the affirmative
defense for malfunctions from the Arizona RH FIP, which applies to both
Coronado and the Cholla Power Plant (Cholla).
DATES: Written comments must be submitted to the designated contact on
or before May 15, 2015. Requests for a public hearing must be received
on or before April 15, 2015.
ADDRESSES: Submit your comments, identified by docket number EPA-R09-
OAR-2015-0165, by one of the following methods:
[[Page 17011]]
Federal Rulemaking portal: http://www.regulations.gov.
Follow the on-line instructions for submitting comments.
Email: [email protected].
Fax: 415-947-3579 (Attention: Thomas Webb).
Mail, Hand Delivery, or Courier: Thomas Webb, EPA Region
9, Air Division (AIR-2), 75 Hawthorne Street, San Francisco, California
94105. Hand and courier deliveries are only accepted Monday through
Friday, 8:30 a.m. to 4:30 p.m., excluding Federal holidays. Special
arrangements should be made for deliveries of boxed information.
See the SUPPLEMENTARY INFORMATION section for further instructions
on where and how to learn more about this proposal, attend a public
hearing, or submit comments.
FOR FURTHER INFORMATION CONTACT: Thomas Webb, U.S. EPA, Region 9,
Planning Office, Air Division, Air-2, 75 Hawthorne Street, San
Francisco, CA 94105. Thomas Webb can be reached at telephone number
(415) 947-4139 and via electronic mail at [email protected].
SUPPLEMENTARY INFORMATION:
Table of Contents
I. General Information
II. Background
III. Proposed FIP Revision
IV. EPA's Proposed Action
V. Statutory and Executive Order Reviews
I. General Information
A. Definitions
For the purpose of this document, we are giving meaning to certain
words or initials as follows:
The words or initials Act or CAA mean or refer to the
Clean Air Act, unless the context indicates otherwise.
The initials ADEQ mean or refer to the Arizona Department
of Environmental Quality.
The words Arizona and State mean the State of Arizona.
The initials BART mean or refer to Best Available Retrofit
Technology.
The term Class I area refers to a mandatory Class I
Federal area.\1\
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\1\ Although states and tribes may designate as Class I
additional areas which they consider to have visibility as an
important value, the requirements of the visibility program set
forth in section 169A of the CAA apply only to ``mandatory Class I
Federal areas.''
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The initials CBI mean or refer to Confidential Business
Information.
The initials EGU mean or refer to Electric Generating
Unit.
The words EPA, we, us, or our mean or refer to the United
States Environmental Protection Agency.
The initials FIP mean or refer to Federal Implementation
Plan.
The initials LNB mean or refer to low-NOX
burners.
The initials MMBtu mean or refer to million British
thermal units.
The initials MW mean or refer to megawatts.
The initials NOX mean or refer to nitrogen
oxides.
The initials NP mean or refer to National Park.
The initials OFA mean or refer to over fire air.
The initials RMB mean or refer to RMB Consulting and
Research.
The initials S&L mean or refer to Sargent and Lundy, a
consulting firm.
The initials SCR mean or refer to Selective Catalytic
Reduction.
The initials SIP mean or refer to State Implementation
Plan.
The initials SRP mean or refer to the Salt River Project
Agricultural Improvement and Power District.
The initials UPL mean or refer to Upper Prediction Limit.
B. Docket
The proposed action relies on documents, information, and data that
are listed in the index on http://www.regulations.gov under docket
number EPA-R09-OAR-2015-0165. Although listed in the index, some
information is not publicly available (e.g., Confidential Business
Information (CBI)). Certain other material, such as copyrighted
material, is publicly available only in hard copy form. Publicly
available docket materials are accessible either electronically at
http://www.regulations.gov or in hard copy at the Planning Office of
the Air Division, AIR-2, EPA Region 9, 75 Hawthorne Street, San
Francisco, CA 94105. EPA requests that you contact the individual
listed in the FOR FURTHER INFORMATION CONTACT section to view the hard
copy of the docket from Monday through Friday, 9-5:00 PDT, excluding
Federal holidays.
C. Instructions for Submitting Comments to EPA
Written comments must be submitted on or before May 15, 2015.
Submit your comments, identified by docket number EPA-R09-OAR-2015-
0165, by one of the following methods:
Federal Rulemaking portal: http://www.regulations.gov.
Follow the on-line instructions for submitting comments.
Email: [email protected].
Fax: 415-947-3579 (Attention: Thomas Webb).
Mail, Hand Delivery, or Courier: Thomas Webb, EPA Region
9, Air Division (AIR-2), 75 Hawthorne Street, San Francisco, California
94105. Hand and courier deliveries are only accepted Monday through
Friday, 8:30 a.m. to 4:30 p.m., excluding Federal holidays. Special
arrangements should be made for deliveries of boxed information.
EPA's policy is to include all comments received in the public
docket without change. We may make comments available online at http://www.regulations.gov, including any personal information provided,
unless the comment includes information claimed to be CBI or other
information for which disclosure is restricted by statute. Do not
submit information that you consider to be CBI or that is otherwise
protected through http://www.regulations.gov or email. The http://www.regulations.gov Web site is an ``anonymous access'' system, which
means EPA will not know your identity or contact information unless you
provide it in the body of your comment. If you send an email comment
directly to EPA, without going through http://www.regulations.gov, we
will include your email address as part of the comment that is placed
in the public docket and made available on the Internet. If you submit
an electronic comment, EPA recommends that you include your name and
other contact information in the body of your comment and with any disk
or CD-ROM you submit. If EPA cannot read your comment due to technical
difficulties and cannot contact you for clarification, EPA may not be
able to consider your comment. Electronic files should not include
special characters or any form of encryption, and be free of any
defects or viruses.
D. Submitting Confidential Business Information
Do not submit CBI to EPA through http://www.regulations.gov or
email. Clearly mark the part or all of the information that you claim
as CBI. For CBI information in a disk or CD-ROM that you mail to EPA,
mark the outside of the disk or CD-ROM as CBI and identify
electronically within the disk or CD-ROM the specific information that
is claimed as CBI. In addition to one complete version of the comment
that includes information claimed as CBI, you must submit a copy of the
comment that does not contain the information claimed as CBI for
inclusion in the public docket. We will not disclose information so
marked except in accordance with procedures set forth in 40 CFR part 2.
E. Tips for Preparing Your Comments
When submitting comments, remember to:
Identify the rulemaking by docket number and other
identifying
[[Page 17012]]
information (e.g., subject heading, Federal Register date and page
number).
Explain why you agree or disagree; suggest alternatives
and substitute language for your requested changes.
Describe any assumptions and provide any technical
information and/or data that you used.
If you estimate potential costs or burdens, explain how
you arrived at your estimate in sufficient detail to allow for it to be
reproduced.
Provide specific examples to illustrate your concerns, and
suggest alternatives.
Explain your views as clearly as possible, avoiding the
use of profanity or personal threats.
Make sure to submit your comments by the identified
comment period deadline.
F. Public Hearings
If anyone contacts EPA by April 15, 2015 requesting to speak at a
public hearing, EPA will schedule a public hearing and announce the
hearing in the Federal Register. Contact Thomas Webb at
[email protected] or at (415) 947-4139 to request a hearing or to
determine if a hearing will be held.
II. Background
A. Summary of Statutory and Regulatory Requirements
Congress created a program for protecting visibility in the
nation's national parks and wilderness areas in 1977 by adding section
169A to the CAA. This section of the CAA establishes 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 man-made air pollution.'' \2\ It also directs
states to evaluate the use of retrofit controls at certain larger,
often uncontrolled, older stationary sources in order to address
visibility impacts from these sources. Specifically, section
169A(b)(2)(A) of the CAA requires states to revise their State
Implementation Plans (SIPs) to contain such measures as may be
necessary to make reasonable progress towards the natural visibility
goal, including a requirement that certain categories of existing major
stationary sources built between 1962 and 1977 procure, install, and
operate best available retrofit technology (BART) controls. These
sources are referred to as ``BART-eligible'' sources.\3\ In the 1990
CAA Amendments, Congress amended the visibility provisions in the CAA
to focus attention on the problem of regional haze, which is visibility
impairment produced by a multitude of sources and activities located
across a broad geographic area.\4\ We promulgated the Regional Haze
Rule (RHR) in 1999, which requires states to develop and implement SIPs
to ensure reasonable progress toward improving visibility in mandatory
Class I Federal areas \5\ by reducing emissions that cause or
contribute to regional haze.\6\ Under the RHR, states are directed to
conduct BART determinations for BART-eligible sources that may be
anticipated to cause or contribute to any visibility impairment in a
Class I area.\7\
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\2\ 42 U.S.C. 7491(a)(1).
\3\ 40 CFR 51.301.
\4\ See CAA section 169B, 42 U.S.C. 7492.
\5\ Areas designated as mandatory Class I Federal areas consist
of national parks exceeding 6000 acres, wilderness areas, and
national memorial parks exceeding 5000 acres, and all international
parks that were in existence on August 7, 1977. 42 U.S.C. 7472(a).
When we use the term ``Class I area'' in this action, we mean a
``mandatory Class I Federal area.''
\6\ See generally 40 CFR 51.308.
\7\ 40 CFR 51.308(e).
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B. History of FIP BART Determination
The Arizona Department of Environmental Quality (ADEQ) submitted a
RH SIP (``Arizona RH SIP'') under Section 308 of the RHR to EPA Region
9 on February 28, 2011. The Arizona RH SIP included BART determinations
for NOX, particulate matter (PM), and sulfur dioxide
(SO2) for Units 1 and 2 at the Coronado Generating Station.
We proposed on July 20, 2012, to approve ADEQ's BART determinations for
PM and SO2, but to disapprove its determination for
NOX at Coronado.\8\ In the same notice, we also proposed a
FIP that included a NOX BART emission limit of 0.050 lb/
MMbtu for Unit 1 and 0.080 lb/MMbtu for Unit 2 based on a 30-boiler-
operating-day (BOD) rolling average. These limits correspond to the use
of Selective Catalytic Reduction (SCR) control technology to reduce
NOX emissions. We noted that a consent decree between SRP
and EPA required the installation of SCR and compliance with a
NOX emission limit of 0.080 lb/MMBtu (30-BOD rolling
average) at Coronado Unit 2 by June 1, 2014. We explained that:
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\8\ 77 FR 42834.
. . . the emission limit of 0.080 lb/MMBtu established in the
consent decree was not the result of a BART five-factor analysis,
nor does the consent decree indicate that SCR at 0.080 lb/MMBtu
represents BART. Nonetheless, given the compliance schedule
established in the consent decree and the preliminary information
received from SRP regarding the status of design and construction of
the SCR system, it appears that achieving a 0.050 lb/MMBtu emission
rate may not be technically feasible. Even if it is feasible,
achievement of this emission rate may not be cost-effective.
Therefore, we are proposing an emission limit of 0.080 lb/MMBtu as
BART for NOX at Unit 2. However, if we do not receive
sufficient documentation establishing that achievement of a more
stringent limit is infeasible or not cost-effective, then we may
determine that a more stringent limit for this unit is required in
our final action.\9\
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\9\ 77 FR 42864.
In its comments on our proposal, SRP asserted that a NOX
emission rate of 0.050 lb/MMBtu was not achievable at either of the
Coronado units, due to their startup/shutdown operating profile. In
support of this assertion, SRP submitted reports by two consultants,
Sargent and Lundy (S&L) and RMB Consulting and Research (RMB), which
indicated that the Coronado units could achieve a rolling 30-day
emission rate in the range of 0.053 to 0.072 lb/MMBtu.\10\
Specifically, the S&L report examined the effect of multiple startup/
shutdown events on emission rates over a 30-day period for Unit 2. The
S&L report also examined potential measures to improve the performance
of the current SCR design for Unit 2, including installation of a ``low
load temperature control system.'' We explained the purpose of this
control system in the preamble to our final rule:
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\10\ 77 FR 72555.
As described in the S&L report, periods of low load operation
generally consist of operation between loads of 138 MW to 270 MW
(operation above 270 MW can be considered ``high'' load). Broadly
speaking, the temperature in the SCR system will fall below 599
degrees F during these periods of low load operation, which is the
minimum temperature required for effective NOX control. A
low load temperature control system increases the temperature at the
SCR inlet in order to maintain 599 degrees F, allowing operation of
the SCR system during periods of low load. Without this control
system, the Coronado Unit 2 SCR system will not operate during
periods of low load.\11\
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\11\ Id.
The low-load temperature-control system is referred to as both
``pegging steam'' and ``steam reheat'' in the various documents
submitted by SRP. During periods of low load (138 MW to 270 MW), a
certain amount of steam is routed to the SCR inlet in order to raise
the inlet temperature to above 599 degrees F, which allows for proper
operation of the SCR. At loads below 138 MW, the SCR could not operate
even with the low-load temperature-control system.
In setting the NOX emission limits for Coronado in the
final Arizona RH FIP, we considered the information and analyses
contained in the S&L report
[[Page 17013]]
and the RMB report.\12\ We concluded that:
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\12\ Id. at 72554-56.
In recognition of the work already performed by SRP to meet the
consent decree emission limit of 0.080 lb/MMBtu for Unit 2, and to
avoid interfering with SRP's ability to meet that requirement by the
deadline of June 1, 2014, we have decided not to require a BART
emission limit for Coronado 2 more stringent than 0.080 lb/MMBtu.
Instead, we are finalizing a plant-wide NOX emission
limit for Coronado of 0.065 lb/MMBtu on a rolling 30-day average,
which will provide a sufficient compliance margin for startup and
shutdown events. We are also structuring the compliance
determination method so that, when one of the two units is not
operating, its emissions from the preceding thirty boiler-operating-
days will continue to be included in the two-unit average. We expect
that SRP can meet this limit by installing a low load temperature
control system on Unit 2 and an SCR system including a low load
temperature control system on Unit 1.\13\
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\13\ Id. at 72555.
Please see our final rule published on December 5, 2012, for further
information on the BART determinations and compliance methodology.
C. Petition for Reconsideration and Stay
We received a petition from SRP on February 4, 2013, requesting
partial reconsideration and administrative stay of our final rule under
section 307(d)(7)(B) of the Clean Air Act (CAA) and section 705 of the
Administrative Procedure Act.\14\ EPA Region 9 sent a letter on April
9, 2013, to representatives of SRP informing the company that we were
granting partial reconsideration of the final rule for the Arizona RH
FIP.\15\ In particular, we stated that we were granting reconsideration
of the compliance methodology for NOX emissions from Units 1
and 2 at Coronado and that we would issue a notice of proposed
rulemaking seeking comment on an alternative compliance methodology. We
also noted that, because we initially proposed different NOX
emission limits for the two units, we would seek comment on the
appropriate emission limit for each of the units. Today's notice of
proposed rulemaking includes each of these elements, and constitutes
EPA's proposed action for the reconsideration.
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\14\ Petition of Salt River Project Agricultural Improvement and
Power District for Partial Reconsideration and Stay of EPA's Final
Rule: ``Approval, Disapproval and Promulgation of Air Quality
Implementation Plans; Arizona; Regional Haze State and Federal
Implementation Plans'' (February 4, 2013).
\15\ Letters from Jared Blumenfeld, EPA, to Norman W. Fichthorn
and Aaron Flynn, Hunton and Williams (April 9, 2013).
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III. Proposed FIP Revision
EPA is proposing a unit-specific compliance method and separate
emission limits for NOX on Units 1 and 2 at the Coronado
Generating Station. We also are proposing to revise the work practice
requirement that applies to Coronado and to remove the affirmative
defense for malfunctions that is currently included in the FIP for
Coronado and Cholla.
A. Proposed Compliance Method for Unit-Specific Emission Limits
In a letter sent to EPA on November 18, 2013, SRP outlined its
views concerning the compliance method and emission limit at
Coronado.\16\ Regarding the compliance method, SRP requested that EPA
use the same approach specified in the Consent Decree, noting that this
would ensure ``consistency across applicable requirements.'' \17\ EPA
notes that the Consent Decree contains two different types of
NOX emission limits: Unit-specific 30-day rolling lb/MMBtu
limits and a 365-day plant-wide rolling NOX tonnage
limit.\18\ For purposes of BART, we consider a 30-BOD rolling lb/MMBtu
limit to be appropriate.\19\ Therefore, we propose to set a separate
30-BOD rolling lb/MMBtu limit for each of the two Coronado Units, based
on the following compliance method:
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\16\ Letter from Kelly Barr, SRP, to Deborah Jordan, EPA
(November 18, 2013).
\17\ Id. at 4.
\18\ Consent Decree in United States v. Salt River Project, CV
08-1479-PHX-JAT (D. Az.) (entered Dec. 19, 2008) (``Coronado Consent
Decree'').
\19\ BART Guidelines, 40 CFR part 51, appendix Y, section V
(``For EGUs, 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.'').
The 30-day rolling average NOX emission rate for each
unit shall be calculated in accordance with the following procedure:
First, sum the total pounds of NOX emitted from the unit
during the current boiler operating day and the previous twenty-nine
(29) boiler-operating days; second, sum the total heat input to the
unit in MMBtu during the current boiler operating day and the
previous twenty-nine (29) boiler-operating days; and third, divide
the total number of pounds of NOX emitted during the
thirty (30) boiler-operating days by the total heat input during the
thirty (30) boiler-operating days. A new 30-day rolling average
NOX emission rate shall be calculated for each new boiler
operating day. Each 30-day rolling average NOX emission
rate shall include all emissions that occur during all periods
within any boiler operating day, including emissions from startup,
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shutdown, and malfunction.
This method is identical to that employed for the unit-specific 30-day
rolling lb/MMBtu limit in the Consent Decree, except that it uses the
term ``boiler operating day'' instead of ``Unit Operating Day.'' This
method would replace the plant-wide method promulgated in the final
rule at 40 CFR 52.145(f)(5)(B)(ii). All other compliance-related
requirements, including the monitoring, recordkeeping and reporting
requirements, would remain as promulgated.
B. Proposed Emission Limits for Coronado Units 1 and 2
Because we are proposing to replace the plant-wide average emission
rate limit for NOX with unit-specific limits, we also must
propose separate emission limits for each of the two units at Coronado.
However, we are not reconsidering our determination that BART for
Coronado Units 1 and 2 is an emission limit consistent with the use of
SCR, low-NOX burners (LNB) with over fire air (OFA), and
low-load temperature control. Nor are we conducting a new five-factor
analysis for these units. Rather, we are reconsidering only the
emission limits achievable with SCR and LNB with OFA at Coronado Units
1 and 2. Due to the different regulatory requirements that currently
apply to these units, we have analyzed them separately.
1. Proposed Emission Limit for Coronado Unit 1
a. SRP's Analysis of Unit 1
After EPA granted reconsideration, SRP submitted additional
information to EPA, including two reports prepared by S&L and RMB
concerning the achievability of various NOX emission limits
at Coronado Unit 1.\20\ The 2013 S&L analysis presented modeling
results intended to predict NOX emissions from Unit 1 under
various operating scenarios.\21\ The 2013 RMB report further analyzed
the achievable NOX emission limit at Coronado Unit 1,
``based on the results of S&L's modeling and application of an
appropriate compliance margin.'' \22\ In particular, RMB applied an
``upper prediction limit'' (UPL) technique in order to account for
``the impact of measurement
[[Page 17014]]
uncertainty and other process variation.'' \23\
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\20\ Letter from Kelly J. Barr, SRP, to Deborah Jordan, EPA
(November 18, 2013) and attachments.
\21\ Attachment 1 to November 18, 2013, Letter, Sargent and
Lundy LLC Report SL-011754, Salt River Project Coronado Generating
Station Unit 1 SCR NOX emissions Modeling (November 14,
2013).
\22\ Attachment 2 to November 18, 2013 Letter, Technical
Memorandum from RMB Consulting & Research, Inc. to Salt River
Project NOX limits Compliance monitoring Consideration on
Coronado Unit 1 (October 28, 2013) at 1.
\23\ Id.
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The 2013 S&L report consisted of an emission analysis of the SCR
for Unit 1. Similar to the 2012 S&L report, which concerned Unit 2, the
2013 analysis examined the effect of startup/shutdown events, low-load
cycling, and steam reheat on emissions over a 30-day average. In
summary, the 2013 S&L analysis examined load profile data for Unit 1
for the period from January 1, 2011, through July 31, 2013, and
estimated NOX emission rates with the hypothetical use of
SCR for the various load profiles that occurred during this period.
S&L's estimates of SCR performance and emission rate under various load
profiles are summarized in Table 1. For greater detail, consult the
2013 S&L report, which is included in the docket for this proposed
rule.
Table 1--Unit 1 Load Profile of NOX Emissions
------------------------------------------------------------------------
Unit 1 emission
Load profile rate (lb/MMBtu) Description
------------------------------------------------------------------------
SCR Design Target Emission 0.030 Full load performance
Rate. guarantee per
vendor.
SCR emission rate at full 0.040 Actual controlled NOX
load steady state conditions. emissions are
expected to average
0.01 above the
design target rate.
SCR emission rate when load 0.050 Emission expected to
increasing by more than 10 change as control
MW/hour. systems adjust to
changes in boiler
load, gas flow
rates, and NOX
loading.
SCR emission rate when load 0.035 Emission expected to
decreasing by more than 10 change as control
MW/hour. systems adjust to
changes in boiler
load, gas flow
rates, and NOX
loading.
Emission rate during cold 0.10 Low NOX burners (LNB)
start, oil-firing \24\. only, no SCR during
startup. Unit 1
initially uses fuel
oil for startup, and
transitions to coal
to complete startup.
Emission rate during cold 0.25 LNB only, no SCR
start, coal-firing. during startup.
Emission rate during warm 0.19 LNB only, no SCR
start, oil-firing \25\. during startup. Unit
1 initially uses
fuel oil for
startup, and
transitions to coal
to complete startup.
Emission rate during warm 0.28 LNB only, no SCR
start, coal-firing. during startup.
Emission rate during low load 0.29 For low-load periods
periods. with no steam reheat
(LNB-only, no SCR
control).
SCR emission rate during 0.10 Emission rate during
initial shutdown. shutdown with SCR
inlet >599 degrees
F, allowing for SCR
operation.
Emission rate after SCR 0.45 LNB only. Corresponds
shutdown. to shutdown period
after SCR inlet <599
degrees F.
------------------------------------------------------------------------
Based on the emission rates summarized in Table 1 above, the S&L
analysis examined the 30-day emission rate for Unit 1 assuming several
combinations of startup events and loading profiles. The highest
controlled 30-day average emission rate for several selected scenarios
is presented in Table 2. The full analysis, including selected
spreadsheets that contain the emission rate modeling for certain
operating scenarios, is available in the docket for this proposed
rule.\26\
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\24\ The term ``cold startup'' is not specifically defined by
SRP or S&L in its analysis. Typically, a ``cold startup'' refers to
a startup event that occurs after the boiler has been offline for
approximately 24 to 48 hours or longer. Compared to hot or warm
startups, a cold startup event produces greater emissions because it
is longer in duration and consumes more fuel.
\25\ The term ``hot'' or ``warm'' startup is not defined by SRP
or S&L in its analysis. However, a ``hot'' or ``warm'' typically
refers to a startup event that occurs when the boiler has been
offline for less than 24 hours. Because certain elements of the
boiler may still be hot or warm following shutdown, less time is
required to reach normal operating temperatures and conditions. As a
result, hot and warm startup events produce fewer emissions than
cold startup events because they are shorter in duration and consume
less fuel.
\26\ ``SRP Coronado Generating Station, Unit 1 SCR
NOX Emissions Modeling'', Prepared by Sargent and Lundy,
Report SL-011754, November 14, 2013.
Table 2--Summary of Unit 1 Emission Modeling Results
[Per S&L analysis]
------------------------------------------------------------------------
Controlled NOX emission
Scenario Description rates based on 30-day
average (lb/MMBtu)
------------------------------------------------------------------------
0..................... Full Load high-cycle 0.041
loading.
1b.................... Low-load cycling for 0.048
30 days (with steam
reheat).
5a.................... One cold startup 0.055
with low-load
cycling (with steam
reheat).
5b.................... Two cold startups 0.061
with low-load
cycling (with steam
reheat).
5c.................... Three cold startups 0.065
with low-load
cycling (with steam
reheat).
------------------------------------------------------------------------
The supplemental information submitted by SRP on November 13, 2013,
also included a report from RMB. In this report, RMB stated that it
used equations for calculating the UPL, which is a statistical
technique that examines an existing set of data points and predicts the
chances (i.e., the probability) of future data points (in this case,
emission rates). In general terms, the UPL is a value that is
calculated from a data set that identifies the emission rate that a
source or group of sources is meeting and would be expected to meet a
specified percent of the time that the source is operating. For
example, the 99 percent UPL value is the emission level that the
source(s) would be predicted to be below during 99 out of 100
performance tests. The UPL value is calculated using an
[[Page 17015]]
equation based on the average and variance of a data set (in this
instance, the aforementioned emission rates), the distribution of the
data, quantity of data points, confidence level, and common statistical
values such as t-scores and z-scores. The underlying regulatory concept
behind the use of UPL values is that a source should have only a very
small risk of being determined to be in noncompliance when the emission
control system is actually performing as expected under each type of
normal operation that takes place. UPL values are used in a wide
variety of industries for predictive purposes, including finance,
manufacturing, and healthcare.
RMB stated that it applied the equations for calculating UPL values
to CEMS data for Unit 1, as well as to the CEMS data from three SCR-
equipped coal-fired boilers that it considered comparable to Unit
1.\27\ To summarize, RMB calculated the 99th percentile emission rate
for each of the four units, and compared the 99th percentile emission
rate to the average emission rate of each respective unit. RMB
indicated that for Unit 1, the 99th percentile emission rate was three
to seven percent greater than average emission rates. For the three
SCR-equipped units examined, RMB reports that the 99th percentile
emission rate was approximately 15 percent higher than average emission
rates. RMB then adjusted the average 30-day emission rates from the S&L
emission modeling analysis for each operating scenario upwards by 15
percent in order to account for the variability indicated by the UPL
values. The results of RMB's analysis are summarized in Table 3.
---------------------------------------------------------------------------
\27\ The CEMS data examined for Unit 1 corresponded to operation
with low NOX burners, as Unit 1 does not presently
operate with SCR. For the three other units, CEMS data corresponding
to SCR operation was examined.
Table 3--Summary of Unit 1 Emission Modeling Results
[Per RMB report]
------------------------------------------------------------------------
Controlled NOX emission
Scenario Description rate (30-day average in
lb/MMBtu)
------------------------------------------------------------------------
1b.................... Low-load cycling for 0.055
30 days (with steam
reheat).
5a.................... One cold startup 0.062
with low-load
cycling (with steam
reheat).
5b.................... Two cold startups 0.069
with low-load
cycling (with steam
reheat).
5c.................... Three cold startups 0.073
with low-load
cycling (with steam
reheat).
------------------------------------------------------------------------
RMB then indicated that if the emission limit were considered a
``never to be exceeded value,'' an additional compliance margin should
be incorporated given that the 99th percentile value does not account
for the entire potential range of operating conditions that may occur.
RMB indicated that rounding upwards to the next highest reasonable
interval, 0.080 lb/MMBtu, would provide an approximate 10 percent
compliance margin, and proposed that this value represents the lowest
achievable NOX emission limit for Unit 1. The full RMB
analysis is included in the docket for this proposed rule.
SRP provided additional information to EPA on April 28, 2014, that
included documentation on SCR design parameters for Unit 2, the number
of historical startup events occurring within single 30-day periods for
Units 1 and 2, and expected future operation of Units 1 and 2.\28\
---------------------------------------------------------------------------
\28\ Letter from Kelly J. Barr, SRP, to Deborah Jordan, EPA
(April 28, 2014) and attachments.
---------------------------------------------------------------------------
b. EPA's Evaluation of Unit 1
In proposing a unit-specific limit for Unit 1, we have reviewed
each of the analyses provided by SRP including the emission
spreadsheets developed by S&L for several load profile scenarios. In
addition, we have compared SRP's emission estimates for certain load
profiles with actual Unit 1 emission data as reported to the Air
Markets Program Data (AMPD).\29\ We consider the emission rates used by
S&L for the various load profiles to be reasonable and generally
consistent with emission data reported to AMPD. We also consider the
scenarios examined by S&L to be realistic depictions of load profile
scenarios that were historically experienced by the Coronado units.
AMPD and Energy Information Administration (EIA) records indicate
periods of both high-load and low-load cycling, as well as 30-day
periods with multiple shutdown periods.\30\ The greatest number of cold
startups occurring in a single 30-day period examined by the the S&L
load profile scenarios was three. Although we have not identified an
actual historical 30-day period exhibiting three cold startups, we
consider this a reasonable assumption given both the number of startup
events that have historically occurred,\31\ as well as SRP's
expectation that the Coronado units will experience greater periods of
operation in load-following service or non-operation given the expanded
role of renewable energy sources.\32\ As a result, we consider the
emission rate of 0.065 lb/MMBtu, which corresponds to a scenario
consisting of low-load cycling operations (with steam reheat) and 3
cold startups within a 30-day period, to be a reasonable estimate of
average SCR performance for Unit 1.
---------------------------------------------------------------------------
\29\ As noted in SRP's April 28, 2014 information response, we
requested detailed emission spreadsheets for several scenarios,
including high-load cycling, low-load cycling, and low-load cycling
including multiple startups.
\30\ See spreadsheet ``Coronado 2008-11 NOX Emission
Data (daily).xls''.
\31\ See SRP's April 28, 2014 letter, Attachment A (Multiple
Start Summary).
\32\ See April 28, 2014 letter. Expanded periods of load
following service will result in greater periods of low-load
cycling, as well as increase the need for startup/shutdown events.
---------------------------------------------------------------------------
With regard to the RMB analysis, we are unable to assess fully this
analysis, as it lacked documentation regarding many of its components.
In particular, RMB did not identify the UPL equation(s) it used or the
emission rate characteristics, data distribution, number of emission
rates, or t- or z-scores. RMB did not present specific evidence that
the two SCR-equipped units are representative of how Coronado will
perform when carefully operated after installation of SCR. In
particular, RMB did not address the possibility that the SCR systems on
these two units malfunctioned or were incorrectly operated during the
data period. Accordingly, we are unable to evaluate RMB's assertions
regarding its UPL calculations.
More fundamentally, we do not consider a UPL analysis to be
necessary or appropriate for use in establishing an emission limit for
Coronado Unit 1. Because the UPL method is a statistical technique, it
is essentially an analytical tool that can be applied to any data set
[[Page 17016]]
and produce a UPL value for a specified percentile (i.e., 95th, 98th,
99th percentile, etc). While UPL has been used by EPA to establish
emission standards in other rulemakings, the context for those
rulemakings differs significantly from the context for this action. In
general, EPA has employed the UPL method in instances where it was
necessary to establish an emission standard based on a limited number
of emission measurements, such as when establishing maximum available
control technology (MACT) standards or new source performance standards
(NSPS).\33\ The emission data available for establishing MACT standards
are generally in the form of short-term, three-run stack tests, with
each test-run lasting between one and four hours. These short-term
tests represent three ``snapshots'' of a source's operation and
generally will not represent a source's full range of operations or
emission levels. Accordingly, when establishing an emission standard
that applies continuously across an entire source category, EPA
considers it necessary to account for the emissions and operations over
a fuller range using data sets that encompass longer time periods
(i.e., collected over several months to a year or more of operation).
In such situations, EPA applies the UPL method to predict the emission
levels the source is achieving at times other than when the stack
testing is conducted. For example, it is common for EPA to establish an
emission standard for a particular source category for which only three
to six test results may be available. Because these three to six data
points do not represent the full range of unit operations, the UPL
method is employed to ``fill in the blanks'' when developing an
emission standard that is appropriate for a broader range of
operations. As described in a memo regarding the use of UPL in
establishing MACT standards, ``EPA did not have emissions information
from sources at all times each source was operating, and therefore
determined it was necessary to apply a methodology that addressed the
fact that the data were not complete.'' \34\ Furthermore, while EPA has
used the UPL method in other instances besides MACT standards, such as
in developing NSPS, the emission data sets for those rulemakings were
also very limited, numbering at most in the dozens of test results for
specific source subcategories.
---------------------------------------------------------------------------
\33\ In particular, EPA has used the UPL method in the Mercury
and Air Toxics Standard (MATS), also known as the Boiler MACT, the
Wool Fiberglass MACT, the Phosphoric Acid and Phosphate Fertilizer
MACT, and the Nitric Acid Plant NSPS.
\34\ Memorandum from Susan Fairchild to Docket Number EPA-HQ-
OAR-2010-1041, ``Use of the Upper Prediction Limit for Calculating
MACT Floors'' (July 14, 2014); see also Memo from Susan Fairchild to
Docket No. EPA-HQ-OAR-2010-1041, ``Approach for Applying the Upper
Prediction Limit to Limited Datasets'' (October 6, 2014).
---------------------------------------------------------------------------
By contrast, the data set available here is much more extensive,
represents continuous data collected over a long period of time, and
covers a wider range of unit operations. In particular, the UPL
analyses performed by RMB for Coronado Unit 1 and the three SCR-
equipped coal-fired boilers examined actual emission data from CEMS (or
in the case of Coronado Unit 1, modeled emission data based on actual
load operation) that consisted of thousands of data points collected
continuously over periods of time ranging from eight months to over a
year. As noted above, this is a different context than rulemakings in
which EPA has employed the UPL method to develop category-wide emission
standards based on, at most, a few dozen data points. Given the size
and scope of the data set available in this instance, we propose to
find that the use of the UPL method is not appropriate.\35\
---------------------------------------------------------------------------
\35\ In addition, we note that we consider RMB's application of
its UPL-estimated variability to the results of the S&L modeling
inappropriate. The S&L modeling results already account for
substantial degree of operational variability by assuming a
conservative operating scenario of low-load cycling and 3 cold
startups in a single 30-day period. Applying the UPL-estimated
variability on top of the S&L modeling could be described, to a
degree, as ``double counting'' operational variability.
---------------------------------------------------------------------------
Finally, we do not agree with RMB's suggestion that the emission
limit for Coronado Unit 1 should be rounded up to provide an additional
compliance margin. We note that the UPL methodology used by EPA for
MACT standard development does not include rounding up to the next
highest reasonable interval as suggested by RMB. Given the conservative
nature of the assumptions in the S&L analysis, we do not consider
additional compliance margin appropriate in this instance.
Accordingly, in evaluating an appropriate limit for Coronado Unit
1, we have relied primarily upon the information provided in the S&L
analysis. This analysis found that an emission rate of 0.065 lb/MMBtu
would be appropriate for a scenario consisting of low-load cycling
operations (with steam reheat) and three cold startups within a 30-day
period. As described above, we consider this to be a reasonable
estimate of SCR performance for Coronado Unit 1. We are are therefore
proposing a limit of 0.065 lb/MMBtu on a rolling 30-BOD basis.
2. Proposed Emission Limit for Coronado Unit 2
a. SRP's Analysis of Unit 2
SRP also provided documentation in its April 28, 2014 letter of
Unit 2 design parameters and indicated that it is proceeding with the
installation of a low-load temperature-control system (i.e., steam
reheat) for Unit 2. In addition, SRP stated that the design parameters
demonstrate that Unit 2 was properly designed to meet the 0.080 lb/
MMBtu NOX limit required by the Coronado Consent Decree.
Based on these design parameters and emission modeling performed by
S&L, SRP reiterated that the design of Unit 2 could not accommodate a
NOX emission limit lower than that required by the Consent
Decree. SRP has met certain terms of the Consent Decree by operating
Unit 2 with SCR since June 1, 2014. Finally, in response to an inquiry
from EPA regarding the possibility of a work practice standard for the
SCR system on Unit 2, SRP indicated that certain language from the
Coronado Consent Decree and the Title V operating permit requiring
proper operation of NOX controls are sufficient to ensure
that NOX emissions are minimized.
b. EPA's Evaluation of Unit 2
In our final rule published on December 5, 2012, establishing the
NOX emission limit for Coronado Units 1 and 2, we stated the
following regarding Unit 2:
In recognition of the work already performed by SRP to meet the
consent decree emission limit of 0.080 lb/MMBtu for Unit 2, and to
avoid interfering with SRP's ability to meet that requirement by the
deadline of June 1, 2014, we have decided not to require a BART
emission limit for Coronado 2 more stringent than 0.080 lb/MMBtu.
The information subsequently provided by SRP supports the assertion
that the emission limit in the Consent Decree of 0.080 lb/MMBtu
represents BART for this unit. In particular, the fact that SRP has
already installed a low-load temperature-control system at this unit in
order to meet the 0.080 lb/MMBtu limit suggests that a lower limit
would not be achievable on a 30-BOD basis. As a result, we propose to
set a unit-specific NOX limit for Unit 2 of 0.080 lb/MMBtu,
based on a rolling 30-BOD basis.
In addition, we propose to revise the work practice standard at 40
CFR 52.145(f)(10) to require the operation of the SCR at all times that
Unit 2 is in operation, consistent with technological
[[Page 17017]]
limitations.\36\ As noted in SRP's letter dated April 28, 2014, the
Consent Decree contains a work practice standard for Unit 2. This
language is included in the facility's current Title V operating
permit.\37\ We are proposing to include this same language in the BART
FIP in order to ensure that the SCR is operated at all times during
which it is technologically feasible to do so. In particular, we note
that, based on the information provided by SRP, periods of low-load
operation are a significant element of the Coronado units' operations.
Given the installation of a low-load temperature-control system on Unit
2, the SCR system is now capable of operating at lower loads (i.e.,
between about 138 MW and 270 MW) on Unit 2. Accordingly, we are
proposing to revise the work practice standard in the FIP to ensure
that the SCR system operates during these periods of low-load
operation.
---------------------------------------------------------------------------
\36\ See CAA Section 302(k) (defining ``emission limit'' to
include ``any requirement relating to the operation or maintenance
of a source to assure continuous emission reduction, and any design,
equipment, work practice or operational standard promulgated under
this chapter'').
\37\ Specific Conditions II.E.2.b and c, Title V Operating
Permit No. 52693, issued December 6, 2011.
---------------------------------------------------------------------------
C. Proposed Removal of Affirmative Defense for Malfunctions
The Arizona RH FIP incorporates by reference certain provisions of
the Arizona Administrative Code that establish an affirmative defense
for excess emissions due to malfunctions.\38\ In the interim since
EPA's promulgation of that FIP, the United States Court of Appeals for
the DC Circuit ruled that CAA sections 113 and 304 preclude EPA from
creating affirmative defense provisions in the Agency's own regulations
imposing emission limits on sources.\39\ The court found that such
affirmative defense provisions purport to alter the jurisdiction of
federal courts to assess liability and impose penalties for violations
of those limits in private civil enforcement cases. The court's holding
makes it clear that the CAA does not authorize promulgation of such a
provision by EPA. In particular, the court's decision turned on an
analysis of CAA sections 113 (``Federal enforcement'') and 304
(``Citizen suits''). These provisions apply with equal force to a civil
action brought to enforce the provisions of a FIP. The logic of the
court's decision thus applies to the promulgation of a FIP, and
precludes EPA from including an affirmative defense provision in a FIP.
Furthermore, in light of the DC Circuit's decision, EPA has proposed to
find R18-2-310(B) and R18-2-310(C) substantially inadequate to meet CAA
requirements and to issue a SIP call with respect to these
provisions.\40\ Consistent with the reasoning of the DC Circuit and
EPA's proposed SIP call, we are proposing to remove the affirmative
defense provision in the Arizona Regional Haze FIP. In addition to
Coronado, this revision would also affect Cholla.
---------------------------------------------------------------------------
\38\ See 40 CFR 52.145(f)(11) (incorporating by reference R-18-
2-101, paragraph 65; R18-2-310, sections (A), (B), (D) and (E); and
R18-2-310.01).
\39\ See NRDC v. EPA, 749 F.3d 1055 (D.C. Cir. 2014).
\40\ 79 FR 55920, 55947 (September 17, 2014).
---------------------------------------------------------------------------
D. Non-Interference With Applicable Requirements
The CAA requires that any revision to an implementation plan shall
not be approved by the Administrator if the revision would interfere
with any applicable requirement concerning attainment, reasonable
further progress, or any other applicable requirement of the CAA.\41\
---------------------------------------------------------------------------
\41\ CAA Section 110(l), 42 U.S.C. 7410(l). In this instance EPA
is proposing to promulgate a revision to a FIP, rather than to
approve a revision to a SIP. Although 110(l) on its face applies
only to EPA approvals of plan revisions, we have nonetheless
considered whether this proposed action would interfere with the
requirements of the CAA.
---------------------------------------------------------------------------
EPA has promulgated health-based standards, known as the national
ambient air quality standards (NAAQS), for seven pollutants, including
NO2, a component of NOX, and pollutants such as
ozone and particulate matter with a diameter less than or equal to 2.5
micrometers (PM2.5), that are formed in the atmosphere from
reactions between NOX and other pollutants. Using a process
that considers air quality data and other factors, EPA designates areas
as ``nonattainment'' if those areas violate a NAAQS or cause or
contribute to violations of a NAAQS in a nearby area. Reasonable
further progress, as defined in section 171 of the CAA, is related to
attainment and means ``such annual incremental reductions in emissions
of the relevant air pollutant . . . for the purpose of ensuring
attainment of the applicable [NAAQS].'' Coronado is located in Apache
County, Arizona, which is designated as Unclassifiable/Attainment for
all of the NAAQS. Therefore, we propose to find that a revision to the
BART emission limits for NOX will not interfere with
attainment or reasonable further progress for any air quality standard.
The other requirements of the CAA that are applicable to Coronado
are:
Standards of Performance for New Stationary Sources, 40
CFR part 60, subpart D;
National Emission Standards for Hazardous Air Pollutants,
40 CFR part 63, subpart UUUUU;
Compliance Assurance Monitoring, 40 CFR part 64;
BART and other visibility protection requirements under
CAA sections 110(a)(2)(J) and 169A and 40 CFR part 51, subpart P; and
Interstate transport visibility requirements under CAA
section 110(a)(2)(D)(i)(II).
Today's proposed revisions would not affect the applicable
requirements of the National Emission Standards for Hazardous Air
Pollutants, Standards of Performance for New Stationary Sources, or
Compliance Assurance Monitoring requirements. Therefore, we propose to
find that these revisions would not interfere with these requirements.
The proposed revisions would alter the specific emission limits
that constitute BART for NOX at Coronado under CAA section
169A and 40 CFR 51.308(e). However, we expect the effect of the
proposed changes on visibility will be very small. In particular, we
note that, under the BART Guidelines, the ``degree of visibility
improvement'' expected to result from BART is evaluated through
modeling of the highest emission rate observed on a 24-hour
average.\42\ Although today's rule would raise the emission rate
allowed on a 30-day rolling average, we do not expect that it would
alter the rate on a 24-hour basis. First, the 24-hour maximum emission
rate used in visibility modeling corresponds to operation of the SCR
during periods of full load, steady state operation. As noted
previously, the BART limits proposed in today's rule are still
consistent with the application of SCR. In addition, the underlying
assumptions regarding SCR emission rate and performance remain
unchanged from the December 5, 2012, final rule. Second, the
adjustments to the rolling 30-day emission limit were made to
accommodate periods of startup and shutdown. Specifically, BART limits
for EGUs are established based on a 30-day rolling average and must be
met on a continuous basis, including during periods of startup,
shutdown, and malfunction.\43\ As described previously, the SCR system
requires a certain minimum temperature in order to operate properly. As
a result, there will necessarily be certain periods of time during
startup and shutdown in which the SCR system is not technologically
[[Page 17018]]
capable of operating. This does not alter any of the assumptions
regarding the SCR system when it is in operation, such as the maximum
24-hour emission rate, which is the basis of the visibility modeling.
Moreover, the BART Guidelines recommend that periods of startup and
shutdown be excluded from the visibility modeling.\44\ Therefore, the
degree of visibility improvement would not be significantly diminished.
---------------------------------------------------------------------------
\42\ BART Guidelines 40 CFR part 51, Appendix Y, section IV.D.5.
\43\ See CAA section 302(k).
\44\ Id. section III.A.3 (recommending that ``emissions
reflecting periods of start-up, shutdown, and malfunction'' not be
used for modeling.).
---------------------------------------------------------------------------
With respect to the CAA's reasonable progress requirements under
CAA section 110(a)(2)(J) and 169A, we note that in a September 3, 2014,
final rule, we set reasonable progress goals (RPGs) for Arizona that
accounted for the emission reductions projected to result from
implementation of BART at Coronado (among other sources).\45\ The
revised emission limits we are proposing today will allow for greater
total annual NOX emissions than the FIP. We have therefore
considered the impact of additional emissions on the RPGs. As
summarized in Tables 4 and 5, the difference in NOX
emissions between the Arizona RH FIP and today's proposed rule is
approximately 233 tons per year (tpy).\46\ This amount represents less
than one percent of the projected total NOX emission
reductions in the FIP. Therefore, we consider its potential impact on
the RPGs to be de minimis.
---------------------------------------------------------------------------
\45\ 79 FR 52420, 52468-52469.
\46\ This value assumes that the units will fully operate at the
allowed emission rates in Table 4 and 5 for every month of the year.
Given that the 30-BOD limits are based on conditions that occur
infrequently (i.e., low-load cycling, 3 cold startup/shutdowns),
during many periods the units can be expected to operate at a lower
emission rate. As a result, this value represents a conservative
(i.e., tending to overestimate rather than underestimate in this
context) estimate of the difference in NOX emissions.
---------------------------------------------------------------------------
Finally, CAA section 110(a)(2)(D)(i)(II) requires that all SIPs
contain adequate provisions to prohibit emissions that will interfere
with other states' required measures to protect visibility. In our
final rule of September 3, 2014, we determined that control measures in
the Arizona RH SIP and FIP were sufficient to fulfill this requirement
for the 1997 8-hour ozone, 1997 PM2.5, and 2006
PM2.5 NAAQS.\47\ As noted above, while today's proposal
would allow for an increase in emissions of 233 tpy compared to the
FIP, this represents less than one percent of the projected total
NOX emission reductions in the FIP. Accordingly, we propose
to determine that this change would not alter our determination that
the control measures in the Arizona RH SIP and FIP are adequate to
prevent Arizona's emissions from interfering with other states'
required measures to protect visibility. Thus, we propose to find that
today's proposed revisions would not interfere with any applicable
requirement of the CAA.
---------------------------------------------------------------------------
\47\ 79 FR 52426.
Table 4--Coronado SCR Emission Rate Allowed Under 2012 EPA FIP
--------------------------------------------------------------------------------------------------------------------------------------------------------
Heat duty \1\ NOX emission limit NOX
--------------------- \2\ -----------------------------------------
Unit No. --------------------- Capacity factor \1\
(MMBtu/hr) (lb/MMBtu) (lb/hr) (tpy)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Coronado 1..................................... 4316 0.065 0.84 280.54 2,042
Coronado 2..................................... 3984 ................... 0.89 258.96 ...................
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Supplemental Cost Analysis 2012-11-15.
\2\ Emission limit per FIP final rule, 77 FR 72578.
Table 5--Coronado SCR Emission Rate Allowed Under Proposed 2015 EPA FIP Revision
--------------------------------------------------------------------------------------------------------------------------------------------------------
Heat duty \1\ NOX emission limit NOX
Unit No. ------------------------------------------ Capacity factor \1\ -----------------------------------------
(MMBtu/yr) (lb/MMBtu) (lb/hr) (tpy)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Coronado 1..................................... 4316 0.065 0.84 280.54 2,275
Coronado 2..................................... 3984 0.080 0.89 318.72 ...................
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Supplemental Cost Analysis 2012-11-15.
IV. EPA's Proposed Action
EPA is proposing to revise the Arizona RH FIP to replace a plant-
wide BART compliance method and emission limit for NOX on
Units 1 and 2 at Coronado with a single-unit compliance method and
emission limit on each of the units. As described in today's action, we
are proposing an emission limit of 0.065 lb/MMBtu for Unit 1 and 0.080
lb/MMBtu for Unit 2 with compliance based on a rolling 30-BOD basis.
This revision would constitute our action on SRP's petition for
reconsideration of the FIP. We also are proposing to remove the
affirmative defense for malfunctions in the FIP and revise the work
practice requirement that applies to Coronado.
V. Statutory and Executive Order Reviews
A. Executive Order 12866: Regulatory Planning and Review and Executive
Order 13563: Improving Regulation and Regulatory Review
This action is not a significant regulatory action and was
therefore not submitted to the Office of Management and Budget (OMB)
for review. This rule applies to only two facilities and is therefore
not a rule of general applicability.
B. Paperwork Reduction Act (PRA)
This action does not impose an information collection burden under
the provisions of the Paperwork Reduction Act, 44 U.S.C. 3501 et seq.
This rule applies to only two facilities. Therefore, its recordkeeping
and reporting provisions do not constitute a ``collection of
information'' as defined under 44 U.S.C. 3502(3) and 5 CFR 1320.3(c).
C. Regulatory Flexibility Act (RFA)
I certify that this proposed action will not have a significant
economic impact on a substantial number of small entities. This action
will not impose any requirements on small entities. Firms primarily
engaged in the generation, transmission, and/or distribution of
electric energy for sale are small if, including affiliates, the total
electric output for the preceding fiscal year did not exceed 4 million
megawatt hours. Each of the owners of facilities affected
[[Page 17019]]
by this rule, SRP, Arizona Public Service and PacifiCorp, exceeds this
threshold.
D. Unfunded Mandates Reform Act (UMRA)
This action does not contain an unfunded mandate of $100 million or
more as described in UMRA, 2 U.S.C. 1531-1538, and does not
significantly or uniquely affect small governments.
E. Executive Order 13132: Federalism
This action does not have federalism implications. It will not have
substantial direct effects on the states, on the relationship between
the national government and the states, or on the distribution of power
and responsibilities among the various levels of government.
F. Executive Order 13175: Consultation and Coordination With Indian
Tribal Governments
This action does not have tribal implications, as specified in
Executive Order 13175. It will not have substantial direct effects on
any Indian tribes, on the relationship between the Federal Government
and Indian tribes, or on the distribution of power and responsibilities
between the Federal Government and Indian tribes. Thus, Executive Order
13175 does not apply to this action.
G. Executive Order 13045: Protection of Children From Environmental
Health Risks and Safety Risks
EPA interprets EO 13045 as applying only to those regulatory
actions that concern health or safety risks that EPA has reason to
believe may disproportionately affect children, per the definition of
``covered regulatory action'' in section 2-202 of the Executive Order.
This action is not subject to Executive Order 13045 because it does not
concern an environmental health risk or safety risk.
H. Executive Order 13211: Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution, or Use
This action is not subject to Executive Order 13211 because it is
not a significant regulatory action under Executive Order 12866.
I. National Technology Transfer and Advancement Act
This rulemaking does not involve technical standards. EPA is not
proposing to revise any technical standards or impose any new technical
standards in this action.
J. Executive Order 12898: Federal Actions To Address Environmental
Justice in Minority Populations and Low-Income Populations
EPA believes the human health or environmental risk addressed by
this action will not have potential disproportionately high and adverse
human health or environmental effects on minority, low-income or
indigenous populations. We expect that Coronado will install the same
control technology in order to meet the revised emission limits as
would have been necessary to meet the previously finalized limits. As
shown in Tables 4 and 5 above, the difference in NOX
emissions between the final EPA FIP and today's proposed rule is
approximately 233 tons per year (tpy). Although this is a not a trivial
amount of emissions, it is relatively small compared to the facility's
total emissions. In particular, 233 tpy is equivalent to about 3
percent of the 7,300 tpy of NOX that the facility is
presently allowed to emit under the Coronado Consent Decree.\48\
Furthermore, as shown in Table 5, if today's proposal is finalized,
total NOX emissions from the facility would be roughly 2,275
tpy, a decrease of over 5,000 tpy compared to the plant-wide cap under
the Consent Decree. Thus, although today's proposed revision will allow
for a marginal increase in emissions compared to the FIP, it will still
ensure a significant reduction in emissions compared to present levels.
---------------------------------------------------------------------------
\48\ Coronado Consent Decree, paragraph 44.
---------------------------------------------------------------------------
K. Determination Under Section 307(d)
Pursuant to CAA section 307(d)(1)(B), EPA proposes to determine
that this action is subject to the requirements of CAA section 307(d),
as it revises a FIP under CAA section 110(c).
List of Subjects in 40 CFR Part 52
Environmental protection, Air pollution control, Incorporation by
reference, Nitrogen oxides, Reporting and recordkeeping requirements,
Visibility.
Authority: 42 U.S.C. 7401 et seq.
Dated: March 13, 2015.
Jared Blumenfeld,
Regional Administrator, EPA Region IX.
Part 52, chapter I, title 40 of the Code of Federal Regulations is
proposed to be amended as follows:
PART 52--APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS
0
1. The authority citation for part 52 continues to read as follows:
Authority: 42 U.S.C. 7401 et seq.
Subpart D--Arizona
0
2. In Sec. 52.145, revise paragraphs (f)(3)(i), (f)(5)(ii)(A) and (B),
and (f)(10) and remove paragraph (f)(11) to read as follows:
Sec. 52.145 Visibility protection.
* * * * *
(f) * * *
(3) * * *
(i) NOX emission limitations. The owner/operator of each coal-fired
unit subject to this paragraph (f) shall not emit or cause to be
emitted NOX in excess of the following limitations, in
pounds per million British thermal units (lb/MMBtu) from any coal fired
unit or group of coal-fired units. Each emission limit shall be based
on a rolling 30-boiler-operating-day average, unless otherwise
indicated in specific paragraphs.
------------------------------------------------------------------------
Federal
Coal fired unit or group of coal-fired units emission
limitation
------------------------------------------------------------------------
Cholla Power Plant Units 2, 3, and 4....................... 0.055
Coronado Generating Station Unit 1......................... 0.065
Coronado Generating Station Unit 2......................... 0.080
------------------------------------------------------------------------
* * * * *
(5) * * *
(ii) * * *
(A) Cholla Power Plant. The 30-day rolling average NOX
emission rate for the group of coal-fired units identified as Cholla
Power Plant, Units 2, 3, and 4 shall be calculated for each calendar
day, even if a unit is not in operation on that calendar day, in
accordance with the following procedure: Step one, for each unit, sum
the hourly pounds of NOX emitted during the current boiler-
operating day (or most recent boiler-operating day if the unit is not
in operation), and the preceding twenty-nine (29) boiler-operating
days, to calculate the total pounds of NOX emitted over the
most recent thirty (30) boiler-operating day period for each coal-fired
unit; step two, for each unit, sum the hourly heat input, in MMBtu,
during the current boiler-operating day (or most recent boiler-
operating day if the unit is not in operation), and the preceding
twenty-nine (29) boiler-operating days, to calculate the total heat
input, in MMBtu, over the most recent thirty (30) boiler-operating day
period for each coal-fired unit; step 3, sum together the total pounds
of NOX emitted from the group of coal-fired units over each
unit's most recent thirty (30) boiler-operating day period (the
[[Page 17020]]
most recent 30 boiler-operating day periods for different units may be
different); step four, sum together the total heat input from the group
of coal-fired units over each unit's most recent thirty (30) boiler-
operating day period; and step five, divide the total pounds of
NOX emitted from step three by the total heat input from
step four for each group of coal-fired units, to calculate the 30-day
rolling average NOX emission rate for each group of coal-
fired units, in pounds of NOX per MMBtu, for each calendar
day. Each 30-day rolling average NOX emission rate shall
include all emissions and all heat input that occur during all periods
within any boiler-operating day, including emissions from startup,
shutdown, and malfunction.
(B) Coronado Generating Station. Compliance with the NOX
emission limits for Coronado Unit 1 and Coronado Unit 2 in paragraph
(f)(3)(i) of this section shall be determined on a rolling 30 boiler-
operating-day basis. The 30-boiler-operating-day rolling NOX
emission rate for each unit shall be calculated in accordance with the
following procedure: Step one, sum the total pounds of NOX
emitted from the unit during the current boiler operating day and the
previous twenty-nine (29) boiler operating days; Step two, sum the
total heat input to the unit in MMBtu during the current boiler
operating day and the previous twenty-nine (29) boiler operating days;
Step three, divide the total number of pounds of NOX emitted
from that unit during the thirty (30) boiler operating days by the
total heat input to the unit during the thirty (30) boiler operating
days. A new 30-boiler-operating-day rolling average NOX
emission rate shall be calculated for each new boiler operating day.
Each 30-boiler-operating-day average NOX emission rate shall
include all emissions that occur during all periods within any boiler
operating day, including emissions from startup, shutdown, and
malfunction.
* * * * *
(10) Equipment operations.--(i) Cholla Power Plant. At all times,
including periods of startup, shutdown, and malfunction, the owner or
operator of Cholla Power Plant Units 2, 3 and 4 shall, to the extent
practicable, maintain and operate each unit including associated air
pollution control equipment in a manner consistent with good air
pollution control practices for minimizing emissions. Pollution control
equipment shall be designed and capable of operating properly to
minimize emissions during all expected operating conditions.
Determination of whether acceptable operating and maintenance
procedures are being used will be based on information available to the
Regional Administrator which may include, but is not limited to,
monitoring results, review of operating and maintenance procedures, and
inspection of each unit.
(ii) Coronado Generating Station. At all times, including periods
of startup, shutdown, and malfunction, the owner or operator of
Coronado Generating Station Unit 1 and Unit 2 shall, to the extent
practicable, maintain and operate each unit in a manner consistent with
good air pollution control practices for minimizing emissions. The
owner or operator shall continuously operate pollution control
equipment at all times the unit it serves is in operation, and operate
pollution control equipment in a manner consistent with technological
limitations, manufacturer's specifications, and good engineering and
good air pollution control practices for minimizing emissions.
Determination of whether acceptable operating and maintenance
procedures are being used will be based on information available to the
Regional Administrator which may include, but is not limited to,
monitoring results, review of operating and maintenance procedures, and
inspection of each unit.
* * * * *
[FR Doc. 2015-07233 Filed 3-30-15; 8:45 am]
BILLING CODE 6560-50-P