[Federal Register Volume 80, Number 13 (Wednesday, January 21, 2015)]
[Proposed Rules]
[Pages 3089-3130]
[FR Doc No: 2014-29569]

Vol. 80

Wednesday,

No. 13

January 21, 2015

Part III

Environmental Protection Agency

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40 CFR Part 63

National Emission Standards for Hazardous Air Pollutants for Major
Sources: Industrial, Commercial, and Institutional Boilers and Process
Heaters; Proposed Rule

Federal Register / Vol. 80 , No. 13 / Wednesday, January 21, 2015 /
Proposed Rules

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 63

[EPA-HQ-OAR-2002-0058; FRL-9919-28-OAR]
RIN 2060-AS09

National Emission Standards for Hazardous Air Pollutants for
Major Sources: Industrial, Commercial, and Institutional Boilers and
Process Heaters

AGENCY: Environmental Protection Agency.

ACTION: Proposed rule.

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SUMMARY: On January 31, 2013, the Environmental Protection Agency (EPA)
finalized amendments to the national emission standards for the control
of hazardous air pollutants (HAP) from new and existing industrial,
commercial, and institutional boilers and process heaters at major
sources of HAP. Subsequently, the EPA received 10 petitions for
reconsideration of the final rule. The EPA is announcing
reconsideration of and requesting public comment on three issues raised
in the petitions for reconsideration, as detailed in the SUPPLEMENTARY
INFORMATION section of this notice. The EPA is seeking comment only on
these three issues. The EPA will not respond to any comments addressing
any other issues or any other provisions of the final rule.
Additionally, the EPA is proposing amendments and technical corrections
to the final rule to clarify definitions, references, applicability and
compliance issues raised by stakeholders subject to the final rule.
Also, we propose to delete rule provisions for an affirmative defense
for malfunction in light of a recent court decision on the issue.

DATES: Comments. Comments must be received on or before March 9, 2015,
or 30 days after date of public hearing if later.
    Public Hearing. If anyone contacts us requesting to speak at a
public hearing by January 26, 2015, a public hearing will be held on
February 5, 2015. If you are interested in attending the public
hearing, contact Ms. Pamela Garrett at<PHONE_NUMBER> or by email at
<EMAIL_ADDRESS>to verify that a hearing will be held.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-HQ-
OAR-2002-0058, by one of the following methods:
     Federal eRulemaking Portal: http://www.regulations.gov:
Follow the on-line instructions for submitting comments.
     Email<EMAIL_ADDRESS>Include docket ID No. EPA-
HQ-OAR-2002-0058 in the subject line of the message.
     Fax:<PHONE_NUMBER>, Attention Docket ID No. EPA-HQ-OAR-
2002-0058.
     Mail: Environmental Protection Agency, EPA Docket Center
(EPA/DC), Mail Code 28221T, Attention Docket ID No. OAR-2002-0058, 1200
Pennsylvania Avenue NW., Washington, DC 20460. The EPA requests a
separate copy also be sent to the contact person identified below (see
FOR FURTHER INFORMATION CONTACT).
     Hand/Courier Delivery: EPA Docket Center, Room 3334, EPA
WJC West Building, 1301 Constitution Avenue NW., Washington, DC 20004,
Attention Docket ID No. EPA-HQ-OAR-2002-0058. Such deliveries are only
accepted during the Docket's normal hours of operation, and special
arrangements should be made for deliveries of boxed information.
    Instructions: Direct your comments to Docket ID No. EPA-HQ-OAR-
2002-0058. The EPA's policy is that all comments received will be
included in the public docket without change and may be made available
on-line at www.regulations.gov, including any personal information
provided, unless the comment includes information claimed to be
Confidential Business Information (CBI) or other information whose
disclosure is restricted by statute. Do not submit information that you
consider to be CBI or otherwise protected through www.regulations.gov
or email. The www.regulations.gov Web site is an ``anonymous access''
system, which means the 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 the EPA without going through
www.regulations.gov, your email address will be automatically captured
and included as part of the comment that is placed in the public docket
and made available on the Internet. If you submit an electronic
comment, the 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 the EPA cannot read your comment due to technical
difficulties and cannot contact you for clarification, the EPA may not
be able to consider your comment. Electronic files should avoid the use
of special characters, any form of encryption, and be free of any
defects or viruses.
    Public Hearing: If anyone contacts the EPA requesting a public
hearing by January 26, 2015, the public hearing will be held on
February 5, 2015 at the EPA's campus at 109 T.W. Alexander Drive,
Research Triangle Park, North Carolina. The hearing will begin at 10:00
a.m. (Eastern Standard Time) and conclude at 5:00 p.m. (Eastern
Standard Time). There will be a lunch break from 12:00 p.m. to 1:00
p.m. Please contact Ms. Pamela Garrett at<PHONE_NUMBER> or at
<EMAIL_ADDRESS>to register to speak at the hearing or to
inquire as to whether or not a hearing will be held. The last day to
pre-register in advance to speak at the hearing will be February 2,
2015. Additionally, requests to speak will be taken the day of the
hearing at the hearing registration desk, although preferences on
speaking times may not be able to be fulfilled. If you require the
service of a translator or special accommodations such as audio
description, please let us know at the time of registration. If you
require an accommodation, we ask that you pre-register for the hearing,
as we may not be able to arrange such accommodations without advance
notice. The hearing will provide interested parties the opportunity to
present data, views or arguments concerning the proposed action. The
EPA will make every effort to accommodate all speakers who arrive and
register. Because the hearing is being held at a U.S. government
facility, individuals planning to attend the hearing should be prepared
to show valid picture identification to the security staff in order to
gain access to the meeting room. Please note that the REAL ID Act,
passed by Congress in 2005, established new requirements for entering
federal facilities. If your driver's license is issued by Alaska,
American Samoa, Arizona, Kentucky, Louisiana, Maine, Massachusetts,
Minnesota, Montana, New York, Oklahoma or the state of Washington, you
must present an additional form of identification to enter the federal
building. Acceptable alternative forms of identification include:
Federal employee badges, passports, enhanced driver's licenses and
military identification cards. In addition, you will need to obtain a
property pass for any personal belongings you bring with you. Upon
leaving the building, you will be required to return this property pass
to the security desk. No large signs will be allowed in the building,
cameras may only be used outside of the building and demonstrations
will not be allowed on federal property for security reasons. The EPA
may ask clarifying questions during the oral presentations, but will
not respond to the presentations at that time. Written statements and
supporting information submitted during the comment period will be
considered with the same weight

as oral comments and supporting information presented at the public
hearing. A hearing will not be held unless requested.
    Docket: All documents in the docket are listed in the
www.regulations.gov index. Although listed in the index, some
information is not publicly available, e.g., CBI or other information
whose disclosure is restricted by statute. Certain other material, such
as copyrighted material, will be publicly available only in hard copy.
Publicly available docket materials are available either electronically
in www.regulations.gov or in hard copy at the EPA Docket Center (EPA/
DC), Room 3334, EPA WJC West Building, 1301 Constitution Ave., NW.,
Washington, DC. The Public Reading Room is open from 8:30 a.m. to 4:30
p.m., Monday through Friday, excluding legal holidays. The telephone
number for the Public Reading Room is<PHONE_NUMBER>, and the telephone
number for the Air Docket is<PHONE_NUMBER>.

FOR FURTHER INFORMATION CONTACT: Mr. Jim Eddinger, Energy Strategies
Group, Sector Policies and Programs Division (D243-01), Environmental
Protection Agency, Research Triangle Park, North Carolina 27711;
telephone number:<PHONE_NUMBER>; facsimile number:<PHONE_NUMBER>;
email address<EMAIL_ADDRESS>
SUPPLEMENTARY INFORMATION: Organization of this Document. The following
outline is provided to aid in locating information in the preamble.

I. General Information
    A. What is the source of authority for the reconsideration
action?
    B. What entities are potentially affected by the reconsideration
action?
    C. What should I consider as I prepare my comments for the EPA?
II. Background
III. Discussion of the Issues under Reconsideration
    A. Startup and Shutdown Provisions
    B. CO Limits Based on a Minimum CO Level of 130 ppm
    C. Use of PM CPMS Including Consequences of Exceeding the
Operating Parameter
IV. Technical Corrections and Clarifications
V. Affirmative Defense for Violation of Emission Standards During
Malfunction
VI. Solicitation of Public Comment and Participation
VII. Statutory and Executive Order Reviews
    A. Executive Order 12866: Regulatory Planning and Review and
Executive Order 13563: Improving Regulation and Regulatory Review
    B. Paperwork Reduction Act (PRA)
    C. Regulatory Flexibility Act (RFA)
    D. Unfunded Mandates Reform Act (UMRA)
    E. Executive Order 13132: Federalism
    F. Executive Order 13175: Consultation and Coordination With
Indian Tribal Governments
    G. Executive Order 13045: Protection of Children From
Environmental Health Risks and Safety Risks
    H. Executive Order 13211: Actions Concerning Regulations That
Significantly Affect Energy Supply, Distribution, or Use
    I. National Technology Transfer and Advancement Act
    J. Executive Order 12898: Federal Actions To Address
Environmental Justice in Minority Populations and Low-Income
Populations

I. General Information

A. What is the source of authority for the reconsideration action?

    The statutory authority for this action is provided by sections 112
and 307(d)(7)(B) of the Clean Air Act as amended (42 U.S.C. 7412 and
7607(d)(7)(B)).

B. What entities are potentially affected by the reconsideration
action?

    Categories and entities potentially regulated by this action
include:

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                   Category                      NAICS Code \1\     Examples of potentially regulated entities
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Any industry using a boiler or process heater                211  Extractors of crude petroleum and natural gas.
 as defined in the final rule.
                                                             321  Manufacturers of lumber and wood products.
                                                             322  Pulp and paper mills.
                                                             325  Chemical manufacturers.
                                                             324  Petroleum refineries, and manufacturers of
                                                                   coal products.
                                                   316, 326, 339  Manufacturers of rubber and miscellaneous
                                                                   plastic products.
                                                             331  Steel works, blast furnaces.
                                                             332  Electroplating, plating, polishing, anodizing,
                                                                   and coloring.
                                                             336  Manufacturers of motor vehicle parts and
                                                                   accessories.
                                                             221  Electric, gas, and sanitary services.
                                                             622  Health services.
                                                             611  Educational services.
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\1\ North American Industry Classification System.

    This table is not intended to be exhaustive, but rather provides a
guide for readers regarding entities likely to be affected by this
action. To determine whether your boiler or process heater is regulated
by this action, you should examine the applicability criteria in 40 CFR
63.7485. If you have any questions regarding the applicability of this
action to a particular entity, consult either the air permitting
authority for the entity or your EPA regional representative, as listed
in 40 CFR 63.13 of subpart A (General Provisions).

C. What should I consider as I prepare my comments for the EPA?

    Submitting CBI. Do not submit this information to the EPA through
regulations.gov or email. Clearly mark the part or all of the
information that you claim to be CBI. For CBI information in a disk or
CD ROM that you mail to the EPA, mark the outside of the disk or CD ROM
as CBI and then 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, a copy of the comment that does not contain the information
claimed as CBI must be submitted for inclusion in the public docket.
Information so marked will not be disclosed except in accordance with
procedures set forth in 40 CFR part 2. Send or deliver information
identified as CBI to only the following address: Mr. Jim Eddinger, c/o
OAQPS Document Control Officer (Mail Drop C404-02), U.S. EPA, Research
Triangle Park, NC 27711, Attention Docket ID No. EPA-HQ-OAR-2002-0058.
    Docket. The docket number for this notice is Docket ID No. EPA-HQ-
OAR-2002-0058.
    World Wide Web (WWW). In addition to being available in the docket,
an electronic copy of this notice will be posted on the WWW through the

Technology Transfer Network Web site (TTN Web). Following signature,
the EPA will post a copy of this notice at http://www.epa.gov/ttn/atw/boiler/boilerpg.html. The TTN provides information and technology
exchange in various areas of air pollution control.

II. Background

    On March 21, 2011, the EPA promulgated national emissions standards
for hazardous air pollutants (NESHAP) for the Major Source Boilers and
Process Heaters source category. The EPA received a number of petitions
for reconsideration on that action, and granted reconsideration on
certain issues raised in the petitions. On January 31, 2013, the EPA
promulgated amendments to the NESHAP for new and existing industrial,
commercial, and institutional boilers and process heaters located at
major sources (78 FR 7138). Following promulgation of the January 31,
2013, final rule, the EPA received 10 petitions for reconsideration
pursuant to section 307(d)(7)(B) of the Clean Air Act (CAA). The EPA
received petitions dated March 28, 2013, from New Hope Power Company
and the Sugar Cane Growers Cooperative of Florida. The EPA received a
petition dated March 29, 2013, from the Eastman Chemical Company. The
EPA received petitions dated April 1, 2013, from Earthjustice, on
behalf of Sierra Club, Clean Air Council, Partnership for Policy
Integrity, Louisiana Environmental Action Network, and Environmental
Integrity Project; American Forest and Paper Association on behalf of
American Wood Council, National Association of Manufacturers, Biomass
Power Association, Corn Refiners Association, National Oilseed
Processors Association, Rubber Manufacturers Association, Southeastern
Lumber Manufacturers Association, and U.S. Chamber of Commerce; the
Florida Sugar Industry; Council of Industrial Boiler Owners, American
Municipal Power, Inc., and American Chemistry Council; American
Petroleum Institute; and the Utility Air Regulatory Group which also
submitted a supplemental petition on July 3, 2013. Finally, the EPA
received a petition dated July 2, 2013, from the Natural Environmental
Development Association's Clean Air Project and the Council of
Industrial Boiler Owners. The petitions are available for review in the
rulemaking docket (see Docket ID No. EPA-HQ-OAR-2002-0058).
    On August 5, 2013, the EPA issued letters to the petitioners
granting reconsideration on three specific issues raised in the
petitions for reconsideration and indicating that the agency would
issue a Federal Register notice regarding the reconsideration
process.\1\ This action requests comment on the three issues for which
the EPA granted reconsideration and proposes certain revisions to the
definitions of startup and shutdown and the work practices that apply
during startup and shutdown periods. Additionally, the letters
indicated that the EPA intends to make certain clarifying changes and
corrections to the final rule, some of which were also raised in the
petitions for reconsideration. This action proposes revisions to the
regulatory text that would make those clarifications and corrections.
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    \1\ The EPA is still reviewing the other issues raised in the
petitions for reconsideration and is not taking any action at this
time with respect to those issues.
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III. Discussion of the Issues Under Reconsideration

    The EPA took final action on its proposed amendments to the March
2011 NESHAP on January 31, 2013, (78 FR 7138) to address certain issues
raised in the petitions for reconsideration of the 2011 NESHAP.
    The January 31, 2013, amendments revised, among other things, the
definitions of ``startup'' and ``shutdown'' as well as the work
practice requirements for the startup and shutdown periods. The
amendments also established a carbon monoxide (CO) threshold level as
an appropriate minimum maximum achievable control technology (MACT)
floor level that adequately assures sources will be controlling organic
HAP emissions to MACT levels. The amendments also replaced the
requirement for certain units to install and operate a continuous
emission monitoring system (CEMS) measuring particulate matter (PM)
emissions with a requirement to install and operate a PM continuous
parameter monitoring system (CPMS) which established reporting
requirements for deviations and established conditions under which PM
CPMS deviations would constitute a presumptive violation of the NESHAP.
The EPA received petitions for reconsideration of certain aspects of
these requirements, and granted reconsideration of the following three
issues on August 5, 2013, to provide an additional opportunity for
public comment:
     Definition of startup and shutdown periods and the work
practices that apply during such periods;
     Revised CO limits based on a minimum CO level of 130 parts
per million (ppm); and
     The use of PM CPMS, including the consequences of
exceeding the operating parameter.
    The reconsideration petitions stated that the public lacked
sufficient opportunity to comment on these provisions. Although these
provisions were established after consideration of public comments
received on the proposed rule, the EPA is granting reconsideration on
these issues in order to allow an additional opportunity for comment.
These issues are discussed in more detail in the following sections.
    For the startup and shutdown provisions, the EPA is proposing
certain revisions to the definitions of startup and shutdown and to the
work practice standard that applies during the startup and shutdown
periods. The proposed revision to the definition of startup is the
addition of an alternate definition of startup. The revision to the
work practice standard that applies during the startup period is the
addition of an alternate work practice provision regarding the engaging
of control devices that applies during startup periods. The EPA is not
proposing revisions to the CO limits or the use of PM CPMS, but will
consider any input that we receive in this additional public comment
opportunity.
    Additionally, the EPA is proposing certain clarifying changes and
corrections to the final rule, some of which were also raised in the
petitions for reconsideration. Specifically, these are: (1) Clarify
issues related to the applicability of the major source boiler rule to
natural gas-fired electric utility steam generating units (EGUs); (2)
clarify the compliance date for coal- or oil-fired EGUs that become
subject to the major source boiler rule; (3) correct a conversion error
in the MACT floor calculation for existing hybrid suspension grate
boilers; (4) clarify certain recordkeeping requirements, including, for
example, those related to records for periods of startup and shutdown
for boilers and process heaters in the Gas 1 subcategory. The EPA also
proposes to clarify and correct certain inadvertent inconsistencies in
the final rule regulatory text, such as removal of unnecessary
references to statistical equations, inclusion of averaging time for
operating load limits in Table 8 to the final rule, and correction of
the compliance date for new sources to reflect the effective date of
the final rule.

A. Startup and Shutdown Provisions

    The EPA received petitions asserting that the public lacked an
opportunity to comment on the startup and shutdown provisions amended
in the January

2013, final rule. Specifically, petitioners asserted that the
definitions of ``startup'' and ``shutdown'' in the amended final rule
failed to address restarts of process heaters and that the provisions
for work practice standards did not adequately address fuels considered
``clean'' and operational limitations for certain pollution control
devices.
    In response to petitions for reconsideration received on the March
2011 NESHAP, the EPA proposed definitions of ``startup'' and
``shutdown'' in December 2011 that were based on load specifications.
The EPA received comments on the proposed definitions stating that load
specifications within the definitions were inconsistent with either
safe or normal (proper) operation of the various types of boilers and
process heaters encountered within the source category. As the basis
for defining periods of startup and shutdown, a number of commenters
suggested that the EPA instead use the achievement of various steady-
state conditions. The definitions in the January 2013 final rule
addressed these comments by defining startup and shutdown based on the
time during which fuel is fired in a boiler or process heater for the
purpose of supplying steam or heat for heating and/or producing
electricity or for any other purpose. As explained in the preamble to
the January 2013 final rule, the EPA believes these definitions are
appropriate because boilers and process heaters function to provide
steam or heat; therefore, boilers and process heaters should be
considered to be operating normally at all times steam or heat of the
proper pressure, temperature and flow rate is being supplied to a
common header system or energy user(s) for use as either process steam
or for the cogeneration of electricity.
    The EPA also proposed work practices for startup and shutdown
periods in the December 2011 notice, which generally required employing
good combustion practices. In the January 2013 final rule, the EPA
revised the proposed work practice standards after consideration of
comments received. Among other things, the revised final work practice
standards required sources to combust clean fuels during startup and
shutdown periods and required sources to engage air pollution control
devices (APCDs) when coal, biomass or heavy oil are fired in the boiler
or process heater. (See 78 FR 7198-99.)
    We are granting reconsideration on the definitions of startup and
shutdown and the work practices that apply during these periods that
are in the January 2013 final rule and are also proposing certain
revisions to these aspects of the startup and shutdown provisions that
are in the January 2013 final rule. We are also proposing an alternate
definition of startup and an alternate work practice provision
regarding the engaging of pollution control devices.
1. Definitions
    We are soliciting comment on the definition of startup and shutdown
that were promulgated in the January 2013 final rule, with the
clarifying revisions explained below. We are proposing to revise the
definitions of startup and shutdown in this reconsideration notice as
set forth in 40 CFR 63.7575. Petitioners asserted that the final rule's
definitions of startup and shutdown were not sufficiently clear. We are
proposing to revise the definitions as explained below.
    a. Definition of Startup Period. In addition to soliciting public
comment on the definition of startup contained in the January 2013
final rule, the EPA is proposing to add an alternate definition to the
definition of startup that is in the January 2013 final rule. We are
proposing to allow sources to use either definition of startup when
complying with the startup requirements. As explained in more detail
below, under the alternate definition, startup would end four hours
after the unit begins supplying useful thermal energy.
    Specifically, the EPA is proposing the alternate definition to
clarify that, in terms of the first-ever firing of fuel, startup begins
when fuel is fired for the purpose of supplying useful thermal energy
(such as steam or heat) for heating, process, cooling, and/or producing
electricity and to clarify that startup ends 4 hours after when the
boiler or process heater makes useful thermal energy. The proposed
clarification regarding the end of startup would apply to first-ever
startups as well as startups occurring after shutdown events. With
regard to when startup begins after a shutdown event, the alternate
definition is the same as the definition in the January 31, 2013, final
rule. That is, startup begins with the firing of fuel in a boiler for
any purpose after a shutdown event.
    In this alternate definition, we are proposing the clarification
regarding the first-ever firing of fuel to address implementation
issues regarding ``pre-startup'' activities that are done as part of
installing a new boiler or process heater. Under the January 2013
definition of ``startup,'' a new boiler or process heater would be
considered to have started up, and be subject to the rule, when it
first fires fuel ``for any purpose.'' However, a newly installed unit
needs to be tested to ensure that it was properly installed and will
operate as it was designed and that all associated components were also
properly installed and will operate as designed. The EPA did not intend
for the startup period to begin when newly installed units first fire
fuel for testing or other pre-startup purposes because such firing of
fuel does not represent normal operation of the unit.
    The EPA is also proposing in the alternate definition to replace
the term ``steam and heat'' in the January 2013 definition of startup
with the term ``useful thermal energy.'' This proposed revision would
apply to first-ever startups as well as startups after shutdown events
and is intended to address the issue raised by petitioners that the
language in the January 2013 definition regarding the end of the
startup period is ambiguous since once fuel is fired some steam or heat
is generated but not in useful or controllable quantities. The
petitioners comment that it takes time for steam and process fluid to
be heated to adequate temperatures and pressures for beneficial use and
that steam or heat should not be construed to be supplied until it is
of adequate temperature and pressure. The EPA agrees with petitioners
that the startup period should not end until such time as fuel is fired
resulting in steam or heat that is useful thermal energy because it
takes time for steam and process fluids to be heated to adequate
temperatures and pressures for beneficial use. We believe the
appropriate criteria for ending startup in the definition should be
when useful steam is supplied. This proposed change doesn't alter EPA's
determination that it is not technically feasible to require stack
testing, in particular, to complete the multiple required test runs
during periods of startup and shutdown due to physical limitations and
the short duration of startup and shutdown periods.
    In order to clarify the term ``useful thermal energy,'' we are
proposing a definition for ``useful thermal energy'' as follows:
    Useful thermal energy means energy (i.e., steam, hot water, or
process heat) that meets the minimum operating temperature and/or
pressure required by any energy use system that uses energy provided by
the affected boiler or process heater.
    The EPA received several petitions for reconsideration of the
definition of startup in the January 2013 final rule. The petitioners
commented that this definition does not account for a wide range of
boilers that operationally are

still in startup mode even after some steam or heat is supplied to the
plant. Specifically, the petitioners commented that what constitutes
``startup'' for all boilers varies widely. For example, petitioners
claimed that some boilers begin to supply steam or heat for some
purposes onsite before they have achieved necessary temperature or load
to engage emission controls.
    The petitioners commented that according to the final rule, a
boiler supplying even a small amount of steam would no longer be in
startup and would be required at that point in time to engage emission
controls. However, petitioners noted that according to equipment
specifications and established safe boiler operations, a boiler
operator should not engage emission controls until specific parameters
are met.
    The petitioners expressed that, above all, the boiler/process
heater operator's primary concern during startup is safety. The startup
procedures must ensure that the equipment is brought up to normal
operating conditions in a safe manner, and startup ends when the
boiler/process heater and its controls are fully functional. The end of
startup occurs when safe, stable operating conditions are reached,
after emissions controls are properly operating. The startup provisions
should not include requirements that could affect safe operating
practices.
    The EPA agrees with the petitioners that the startup period should
not end until such time that all control devices have reached stable
conditions. The EPA has very limited information specifically for
industrial boilers on the hours needed for controls to reach stable
conditions after the start of supplying useful thermal energy. However,
the EPA does have information for EGUs on the hours to stable control
operation after the start of electricity generation. Using hour-by-hour
emissions and operation data for EGUs reported to the agency under the
Acid Rain Program, we found that controls used on the best performing
12 percent EGUs reach stable operation within 4 hours after the start
of electricity generation. See technical support document titled
``Assessment of Startup Period at Coal-Fired Electric Generating
Units--Revised'' in the docket. Since the types of controls used on
EGUs are similar to those used on industrial boilers and the start of
electricity generation is similar to the start of supplying useful
thermal energy, we believe that the controls on the best performing
industrial boilers would also reach stable operation within 4 hours
after the start of supplying useful thermal energy and have included
this timeframe in the proposed alternate definition.\2\ This conclusion
is supported by the very limited information (13 units) the EPA does
have on industrial boilers and by information submitted by the Council
of Industrial Boiler Owners obtained from an informal survey of its
members on the time needed to reach stable conditions during startup.
We welcome comment and additional information on this point during the
public comment period.
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    \2\ It is important to remember that the hour at which startup
ends is the hour at which reporting for the purpose of determining
compliance begins. Therefore, sources must collect and report
operating limit data following the end of startup. These data are
used in calculating whether a source is in compliance with the 30-
day average operating limits.
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    b. Definition of Shutdown. In today's action, the EPA is proposing
to revise the definition of shutdown in the January 2013 final rule.
The EPA is proposing to clarify that shutdown begins when the boiler or
process heater no longer makes useful thermal energy and ends when the
boiler or process heater no longer makes useful thermal energy and no
fuel is fired in the boiler or process heater. Specifically, the EPA is
proposing to revise the regulatory text to replace the term ``steam and
heat'' with the term ``useful thermal energy'' to address the same
issue as raised by petitioners regarding the language in the definition
of ``startup'' described above. The EPA did not intend for the shutdown
period to begin until such time as fuel is no longer fired for the
purpose of creating useful thermal energy.
    The EPA received several petitions for reconsideration of the
definition of shutdown in the January 2013 final rule. The petitioners
expressed concerns that the definition is problematic for units firing
solid fuels on a grate or in a fluidized bed combustor where the
residual material in the unit keeps burning after fuel feed to the unit
is stopped. In this case, petitioners explained that fuel is still
burning (``being fired'') in the unit despite the fact that load
reduction is occurring, additional fuel is not being fed, and the
shutdown process has clearly begun. For this reason, petitioners
recommend that the shutdown definition be revised to state that
shutdown begins either when none of the steam and heat from the boiler
or process heater is supplied for heating and/or producing electricity
or when fuel is no longer being fed to the boiler or process heater and
that shutdown ends when there is both no steam or heat being supplied
and no fuel being combusted in the boiler or process heater.
    The EPA agrees with the petitioners' concerns and intended that the
shutdown period would begin when fuel is no longer being fired for the
purpose of creating useful thermal energy. The proposed revisions would
address the concern raised by the petitioner. The proposed revision is
appropriate because as the petitioners commented, for certain types of
boilers where the fuel is combusted on a grate or bed, fuel firing may
be considered to continue even after fuel feed to the unit is stopped.
2. Work Practice Standards
    In today's action, the EPA is proposing to revise the work practice
standards in the January 2013 final rule that apply during periods of
startup and shutdown. Specifically, the EPA is proposing revisions to
the list of ``clean fuel'' in the January 2013 final rule and is
proposing an alternate work practice requirement for periods of startup
and shutdown. Sources would have the choice of complying with the work
practice requirement contained in the January 2013 final rule or the
alternate work practice requirement proposed in today's action.
Additionally, EPA is proposing a process through which sources can seek
an extension of the time period by which the alternate work practice
provision requires PM controls to be engaged, based on documented
safety considerations. Finally, EPA is proposing certain recordkeeping
and monitoring requirements that would apply to sources that choose to
comply with the alternate work practice. These proposed provisions are
described in more detail below.
    a. Clean Fuel Requirement. The January 2013 final rule requires
sources to startup on ``clean fuel.'' The definition of ``clean fuel''
includes several fuels but does not include coal or biomass or other
solid fuels that many sources use during boiler startup. In the
December 2011 proposed rule, we solicited comment on ``whether other
work practices should be required during startup and shutdown,
including requirements to operate using specific fuels to reduce
emissions during such periods.''
    In a petition for reconsideration, the petitioners claimed that the
list of clean fuels, as written, is too narrow. They requested that the
EPA expand the list to include all gaseous fuels meeting the ``other
gas 1'' classification as well as biodiesel, as distillate oil is
sometimes a biodiesel blend. They also requested that fuels that meet
the total selected metals (TSM), hydrogen chloride (HCl),

and mercury emission limits using fuel analysis should be added to the
list of clean fuels. Dry biomass (less than 20-percent moisture
content) should also be added to the list of clean fuels because they
claim it will burn cleaner than other solid fuels. Specifically, they
claim that it is a clean fuel for startup because it exhibits low HCl,
mercury and CO emissions due to its chloride, mercury, and moisture
content, and PM emissions would likely be below the dry biomass
subcategory PM limit. Therefore, the petition states that it is a
reasonable work practice for solid fuel boilers to burn only dry
biomass as clean fuel during startup. In addition, the petition
recommends that permitting authorities should have the flexibility to
approve other clean fuels that EPA may not have considered (e.g., other
renewable fuels).
    We are proposing two changes to the list of clean fuels for
starting up a boiler or process heater. We agree that the list should
include all gaseous fuels meeting the ``other gas 1'' classification.
Also, we agree that any fuels that meet the applicable TSM, HCl and
mercury emission limits using fuel analysis should be added to the list
of clean fuels because their mercury, HCl and metals emissions would be
in compliance with the applicable emission limits without the use of
control devices. Sources would demonstrate compliance either through
fuel analysis for the relevant parameters or stack testing. The EPA
does not believe it is necessary to revise the regulatory text of the
``clean fuel'' definition to specifically include biodiesel on the list
since the definition of ``distillate oil'' in the rule includes
biodiesel.
    b. Engaging Pollution Control Devices. The January 2013 final rule
required boilers and process heaters when they start firing coal/solid
fossil fuel, biomass/bio-based solids, heavy liquid fuel or gas 2
(other) gases to engage applicable pollution control devices except for
limestone injection in fluidized bed combustion (FBC) boilers, dry
scrubbers, fabric filters, selective non-catalytic reduction (SNCR) and
selective catalytic reduction (SCR), which must start as expeditiously
as possible. The EPA received several petitions for reconsideration of
this aspect of the work practice standard.
    The petitioners expressed concerns that the requirement for
engaging applicable control devices does not accommodate potential
safety problems relative to electrostatic precipitator (ESP) operation.
Comments and recommended manufacturer operating procedures provided to
the EPA during the comment period for the December 2011 proposal
explained the potential hazards associated with ESP energization when
unburned fuel may be present with oxygen levels high enough that the
mixture can be in the flammable range. The petitioners referenced these
comments and requested that the EPA needs to reconsider this safety
issue and revise the requirements to include ESP energization with the
other controls that are to be started as expeditiously as possible
rather than when solid fuel firing is first started. In addition, they
claim that the ESP cannot practically be engaged until a certain flue
gas temperature is reached. Specifically, they claim that premature
starting of this equipment will lead to short-term stability problems
that could result in unsafe actions and longer term degradation of ESP
performance due to fouling, increased chances of wire damage, or
increased corrosion within the chambers. They also state that vendors
providing this equipment incorporate these safety and operational
concerns into their standard operating procedures. For example, they
claim that some ESPs have oxygen sensors and alarms that shut down the
ESP at high flue gas oxygen levels to avoid a fire in the unit. The
oxygen level is typically high during startup, so the ESP may not
engage due to these safety controls until more stable operating
conditions are reached. Therefore, the petitioners request that ESPs be
included in the list of air pollution controls that must be started as
expeditiously as possible.
    Considering the petitioners' comments, the EPA is proposing an
alternate work practice requirement for operating air pollution control
devices during periods of startup as follows.
    Boilers and process heaters owners and operators shall, when firing
coal/solid fossil fuel, biomass/bio-based solids, heavy liquid fuel or
gas 2 (other) gases, vent emissions to the main stack(s) and engage all
of the applicable control devices so as to comply with the emission
limits within 4 hours of start of supplying useful thermal energy.
Owners and operators must effect PM control within one hour of first
firing coal/solid fossil fuel, biomass/bio-based solids, heavy liquid
fuel or gas 2 (other) gases. Owners and operators must start all
applicable control devices as expeditiously as possible, but, in any
case, when necessary to comply with other standards applicable to the
source by a permit limit or a rule other than this subpart that require
operation of the control devices.
    The EPA believes that the control technology operation related
requirements we are proposing are practicable and broadly applicable.
Owners and operators of boilers and process heaters have options to
minimize any potential for detrimental impacts on hardware and any
safety concerns, such as using clean fuels until appropriate flue gas
conditions have been reached and then switching to the primary fuel. In
addition, we are proposing in the alternate work practice requirement
that owners and operators of boilers and process heaters, if they have
an applicable emission limit, must develop and implement a written
startup and shutdown plan (SSP) according to the requirements in Table
3 to this subpart and that the SSP must be maintained onsite and
available upon request for public inspection. Also in the alternate
work practice requirement, we are proposing to allow a source to
request a unit-specific case-by-case extension to the 1-hour period for
engaging the PM controls. However, the EPA will only consider
extensions for units that can provide evidence of a documented
manufacturer-identified safety issue and can provide proof that the PM
control device is adequately designed and sized to meet the filterable
PM emission limit. In its request for the case-by-case determination,
the owner/operator must provide, among other materials, documentation
that: (1) The unit is using clean fuels to the maximum extent possible
to alleviate or prevent the safety issue prior to the combustion of
coal/solid fossil fuel, biomass/bio-based solids, heavy liquid fuel or
gas 2 (other) gases in the unit, (2) the source has explicitly followed
the manufacturer's procedures to alleviate or prevent the safety issue,
(3) details the manufacturer's statement of concern, and (4) provides
evidence that the PM control device is adequately designed and sized to
meet the PM emission limit.
    In order to clarify that the work practice does not supersede any
other standard or requirements to which the affected source is subject,
the EPA is including in the proposed alternate work practice provision
a requirement that requires control devices to operate when necessary
to comply with other standards (e.g., new source performance standards,
state regulations) applicable to the source that require operation of
the control device.
    In addition, to ensure compliance with the proposed definition of
startup and the work practice standard that applies during startup
periods, we are proposing that certain events and parameters be
monitored and recorded during the startup periods. These events include
the time when firing (i.e., feeding) starts for coal/solid fossil fuel,

biomass/bio-based solids, heavy liquid fuel or gas 2 (other) gases; the
time when useful thermal energy is first supplied; and the time when
the PM controls are engaged. The parameters to be monitored and
recorded include the hourly steam temperature, hourly steam pressure,
hourly flue gas temperature, and all hourly average CMS data (e.g.,
CEMS, PM CPMS, continuous opacity monitoring systems (COMS), ESP total
secondary electric power input, scrubber pressure drop, scrubber liquid
flow rate) collected during each startup period to confirm that the
control devices are engaged.
    We request comments on (1) the startup and shutdown provisions
(definitions and work practices) in the January 2013 final rule, (2)
the proposed alternate definition for ``startup'' and the proposed
alternate work practice (item 5.c.(2) of Table 3 of proposed rule) for
the startup period, and (3) the recordkeeping requirements being
proposed for the startup periods.

B. CO Limits Based on a Minimum CO Level of 130 ppm

    In the January 2013 final rule, EPA established a CO emission limit
for certain subcategories at a level of 130 ppm, based on an analysis
of CO levels and associated organic HAP emissions reductions. See 78 FR
7144. The EPA received a petition for reconsideration of these CO
limits in the January 2013 final rule. The petitioner claimed that
these limits do not satisfy the statutory requirement that the MACT
standard for existing sources is no less stringent than the average
emission limitation achieved by the best performing twelve percent of
units in the subcategory and that EPA's rationale for adopting these
limits is unrelated to this statutory MACT requirement.
    The EPA revised these particular CO limits in the January 2013
final rule in part based on comments received during the comment period
for the December 2011 proposed rule stating that a CO emission standard
no lower than 100 ppm, corrected to 7-percent oxygen, is adequate to
assure complete control of organic HAP.
    As explained in the preamble to the January 2013 final rule,
formaldehyde was selected as the basis of the organic HAP comparison
because it was the most prevalent organic HAP in our emission database
and a large number (over 300) of paired test runs existed for CO and
formaldehyde. The linear relationship between CO and formaldehyde
emissions exhibits a high correlation for CO levels above 150 ppm,
supporting the selection of CO as a surrogate for organic HAP
emissions. In assessing the correlation between CO and formaldehyde, a
trend can be seen that formaldehyde levels are lowest when CO emissions
are in the range of 150 to 300 ppm. At levels lower than 150 ppm, the
mean levels of formaldehyde appear to increase. Based on this analysis,
we promulgated a minimum MACT floor level for CO of 130 ppm, at 3-
percent oxygen, (which is equivalent to 100 ppm corrected to 7-percent
oxygen) which we believe is protective of human health and the
environment.
    The EPA does not believe the petitioners have provided sufficient
justification that the revised CO limits in the January 2013 final rule
do not satisfy the CAA's statutory floor requirements, and the EPA
continues to believe that these standards do in fact satisfy the CAA's
floor requirements. CAA section 112(d)(3) states that emission
standards for existing sources shall not be less stringent, and may be
more stringent than ``the average emission limitation achieved by the
best performing sources (for which the Administrator has emission
information).'' If ``lowest emitting'' is used as the measure for
determining ``best performing'' sources, then the 130 ppm standard does
satisfy the CAA's floor requirements. When the available formaldehyde
emission information is ranked and the best performing 12 percent
identified, the mathematical average of the best performing units'
corresponding CO emission levels is 240 ppm which is in the range,
previously indicated, that formaldehyde emission levels are lowest.
    However, in consideration of the fact that the public lacked the
opportunity to comment on the CO emission limits established at the
level of 130 ppm, corrected to 3-percent oxygen, the EPA has granted
reconsideration on the CO emission limits established at the level of
130 ppm, corrected to 3-percent oxygen, to provide an additional
opportunity for public comment on those limits. The EPA is not
soliciting comment on any other CO limits, or on other issues relating
to establishment of CO limits, including the question of whether EPA
should establish work practice standards for CO instead of numeric
limits.
    If, after evaluating all comments and data received on this issue,
the EPA determines that amendments to the CO emission limits
established at the level of 130 ppm, corrected to 3-percent oxygen, may
be appropriate, we will propose such amendments in a future regulatory
action.

C. Use of PM CPMS Including Consequences of Exceeding the Operating
Parameter

    The January 2013 amended final rule requires units combusting solid
fossil fuel or heavy liquid with heat input capacities of 250 million
British thermal units per hour (MMBtu/hr) or greater to install,
maintain, and operate PM CPMS. The provisions regarding PM CPMS in the
January 2013 final rule are consistent with regulations for similarly-
sized commercial and industrial solid waste incinerator units, Portland
cement kilns, and EGUs subject to the Mercury and Air Toxics Standards
(MATS) Rule.
    The March 21, 2011, final rule required boilers with a heat input
rate greater than 250 MMBtu/hr from solid fuel and/or residual oil to
install and operate a PM CEMS to demonstrate compliance with the
applicable PM emission limit. In petitions for reconsideration to the
March 2011 final rule, petitioners objected to this requirement,
claiming that the EPA had failed to consider the ability of PM CEMS to
meet the required Performance Specification 11 (PS 11) criteria, or to
accurately measure PM, at the levels of the proposed standards. In the
December 2011 Reconsideration proposal, the EPA acknowledged
petitioners' concerns regarding application of PM CEMS technology to
various types of boilers, and concluded that for coal- and oil-fired
boilers PM CEMS would best be employed as parametric monitors (i.e., as
a PM CPMS). Specifically, rather than correlate the PM CEMS to the EPA
reference method using PS 11, the EPA proposed that sources establish a
site-specific enforceable operating limit in terms of the PM CPMS
output during the initial and periodic performance tests, and meet that
operating limit on a 30-day rolling average basis. However, commenters
objected to the EPA's proposal to impose an enforceable site-specific
operating limit based on output during a short-term stack test which
would not capture the variability in PM CPMS output that may occur
during operations consistent with the PM limit.
    In the January 2013 final rule, the EPA finalized the requirement
for use of a PM CPMS, but added provisions allowing sources a certain
number of exceedances of the operating parameter limit before an
exceedance would be presumed to be a violation, and allowing certain
low emitting sources to ``scale'' their site-specific operating limit
to 75 percent of the emission standard. Specifically, under the January
2013 final rule, boilers opting to

use PM CPMS will establish an operating limit as the average parameter
value (in terms of raw output from a PM CEMS) obtained during the
performance test and, if the boiler did not exceed 75 percent of the
emission limit during the performance test, the boiler may linearly
scale the average parameter value up to 75 percent of the limit to
obtain a new scaled parameter. Compliance with the parameter limit is
determined on a 30-boiler-operating-day rolling average basis. For any
exceedance of the 30-boiler-operating-day PM CPMS value, the owner or
operator must (1) inspect the control device within 48 hours and, if a
cause is identified, take corrective action as soon as possible, and
(2) conduct a new performance test to verify or reestablish the
operating limit within 30 calendar days. Additional exceedances that
occur between the original exceedance and the performance test do not
trigger another test. Up to four performance tests may be triggered in
a 12-month rolling period without additional consequences. However,
each additional performance test that is triggered would constitute a
separate presumptive violation.
    The EPA received a petition for reconsideration on the use of PM
CPMS. Specifically, the petitioner stated that while the option has the
advantage of avoiding the testing issues associated with PS 11
correlations of PM CEMS, absent that correlation the parameter is
nothing more than an indicator that PM may be increasing or decreasing.
Therefore, while it is useful as a tool to identify the need for
investigation and corrective action, the petitioner does not believe it
is an appropriate tool to establish a violation as long as the
requirement for corrective action is met.
    The petitioner claimed that any affected boiler that tests at its
normal operating condition to establish a PM CPMS operating limit could
be testing at a level well below the applicable emission limit. For
such a boiler, the petitioner does not believe there is any basis to
assume that an exceedance (or even multiple exceedances) of a 30-
boiler-operating-day rolling average parameter limit indicates that the
emission limit was exceeded, or that controls were not operated
properly. Rather, the petitioner claims, it simply means that emissions
on average probably were above the level of emissions during the last
successful performance test. Unless the source has collected data to
determine what PM CPMS parameter level is equivalent to a violation of
the emission standard, the petitioner states that there is no basis to
suggest that any parameter exceedance is a violation. The petitioner
also argued that if a source that has invested in a PM CPMS is
conducting appropriate investigations and corrective action in response
to parameter exceedances, there is no basis to label the source a
violator as a result of its fourth successful performance test in a 12-
month period.
    In its petition for reconsideration, the petitioner also expressed
concerns about the scaling procedure that the EPA added to that rule in
an attempt to address the fact that ``actual stack emissions of PM
could still be well below the limit.'' The petitioner expressed
appreciation of the EPA's attempt to address that issue for industrial
boilers by also allowing scaling of the as-tested parameter value.
However, the petitioner claims that EPA's use of 75 percent of the
emission level as the upper point is arbitrary and still puts sources
that are operating with significant compliance margin at risk of a
violation. For a scaled limit to justify a violation, the petitioner
believes that the EPA must establish not only the consistency of the
uncorrelated measurements over time, but allow scaling up to 100
percent of the emission limit. Only at that point would there be a
reasonable basis to conclude that a performance test might have failed.
    In sum, the petitioner claimed that for PM CPMS to be useful as an
alternative to stack testing for compliance with the alternate TSM
standards or PM CEMS, the EPA must (1) allow scaling up to 100 percent
of the emission limit, and (2) remove its definition of a violation in
favor of a pure investigation and corrective action approach.
    The EPA is not proposing to revise the PM CPMS provisions in the
January 31, 2013, final rule. The basis for the inclusion of the
definition of a violation is that the site-specific CPMS limit could
represent an emissions level higher than the proposed numerical
emissions limit since the PM CPMS operating limit corresponds to the
highest of the three runs collected during the Method 5 performance
test. Second, the PM CPMS operating limit reflects a 30-day average
that should represent an actual emissions level lower than the three
test run numerical emissions limit since variability is mitigated over
time. Consequently, we believe that there should be few if any
deviations from the 30-day parametric limit and there is a reasonable
basis for presuming that deviations that lead to multiple performance
tests to represent poor control device performance and to be a
violation of the standard. We continue to believe that there should be
few if any deviations from the 30-day parametric limit and that there
is a reasonable basis for presuming that deviations that lead to
multiple performance tests represent poor control device performance
and therefore constitute a presumptive violation of the standard,
particularly since that presumption can be rebutted. Therefore, we
continue to believe that PM CPMS deviations leading to more than four
required performance tests in a 12-month process operating period
should be presumed a violation of this standard, subject to the
source's ability to rebut that presumption with information about
process and control device operations in addition to the Method 5
performance test results. Therefore, the EPA is not proposing to revise
that PM CPMS provision in the January 2013 final rule.
    Based on an extensive analysis (see S. Johnson's memo
``Establishing an Operating Limit for PM CPMS'', November 2012, docket
ID number EPA-HQ-OAR-2011-0817-0840), we also continue to believe a
scaling factor of 75 percent of the emission limit as a benchmark is
appropriate and are not proposing to revise that provision of the
January 2013 final rule. We recognized that non-linear instruments
provide increased uncertainty in estimating PM concentrations above the
performance test data point and, after considering several options, we
determined that the 75-percent scaling cap was appropriate for
protecting the emission standard in this regard. This option provided
flexibility for low emitting and well-operated sources, and was
determined to be a reasonable compromise between flexibility for the
regulated source and assurance that the emission standard is met.
Seventy-five percent of the emission limit is an already-established
threshold in the Standards of Performance for New Stationary Sources
and Emission Guidelines for Existing Sources: Commercial and Industrial
Solid Waste Incineration Unit (76 FR 15757) to determine the frequency
of subsequent compliance testing. In that rule, owners or operators of
sources were able to reduce their performance test frequency when
emissions were equivalent with or below 75 percent of the limits.
Otherwise, performance testing was to occur at the normal frequency
prescribed in the rule. We believe this threshold can be used in
conjunction within a PM CPMS scaling factor, as results above 75
percent of the equivalent emissions limit would be ineligible for
scaling factor use and could lead to increased performance testing and
potentially to a presumptive

violation, while results equivalent with or below 75 percent of the
emissions limit would be eligible for scaling factor use and provide
greater operational flexibility for sources demonstrating compliance at
lower emission rates.
    For these reasons, the EPA is not proposing to revise the
requirements in 40 CFR 63.7440(a)(18) for demonstrating continuous PM
emission compliance using a PM CPMS. However, the EPA is soliciting
additional comment on these requirements in today's action. The EPA
welcomes comments on these provisions, including whether the provisions
are necessary or appropriate. If a commenter suggests revisions to the
provisions, the commenter should provide detailed information
supporting any such revision.

IV. Technical Corrections and Clarifications

    We are proposing several technical corrections. These amendments
are being proposed to correct inadvertent errors that were promulgated
in the final rule and to make the rule language consistent with
provisions addressed through this reconsideration. We are soliciting
comment only on whether the proposed changes provide the intended
accuracy, clarity and consistency. These proposed changes are described
in Table 1 of this preamble. We request comment on all of these
proposed changes.

Table 1--Miscellaneous Proposed Technical Corrections to 40 CFR Part 63,
                              Subpart DDDDD
------------------------------------------------------------------------
   Section of subpart DDDDD        Description of proposed correction
------------------------------------------------------------------------
40 CFR 63.7491(a)............  Revise the language in this paragraph to
                                clarify that natural gas-fired EGUs as
                                defined in subpart UUUUU are not subject
                                to the rule if firing at least 90
                                percent natural gas.
40 CFR 63.7491(j)............  Revise this paragraph to include the
                                words ``and process heaters'' to clarify
                                that it also applies to process heaters.
40 CFR 63.7491(l)............  Revise this paragraph to include the
                                words ``and process heaters'' to clarify
                                that it also applies to process heaters.
40 CFR 63.7491(n)............  Insert paragraph (n) which was in amended
                                final rule but inadvertently had the
                                wrong amendatory instruction to be
                                included in the CFR.
40 CFR 63.7495(a)............  Revise this paragraph to correctly
                                include the effective date (April 1,
                                2013) instead of the publication date
                                (January 31, 2013) of the amendments.
40 CFR 63.7495(e)............  Revise this paragraph to add the language
                                which was in amended final rule but
                                inadvertently had the wrong amendatory
                                instruction to be included in the CFR.
40 CFR 63.7495(f)............  Revise this paragraph to correctly list
                                the date (January 31, 2016) after which
                                existing EGUs that become subject to the
                                rule must be in compliance.
40 CFR 63.7495(h) and (i)....  Insert these paragraphs to clarify when
                                existing and new affected units that
                                switch subcategories due to fuel switch
                                or physical change must be in compliance
                                with the provisions of the new
                                subcategory.
40 CFR 63.7500(a)............  Revise this paragraph to delete the comma
                                after ``paragraphs (b).''
40 CFR 63.7500(a)(1)(ii).....  Revise this paragraph by adding the words
                                ``on or'' to include May 20, 2011.
40 CFR 63.7500(a)(1)(iii)....  Revise this paragraph by adding the words
                                ``on or'' to include December 23, 2011
                                and to correctly include the effective
                                date (April 1, 2013) instead of the
                                publication date (January 31, 2013) of
                                the amendments.
40 CFR 63.7500(f)............  Revise this paragraph to clarify that
                                only items 5 and 6 of Table 3 apply
                                during periods of startup and shutdown.
40 CFR 63.7505(a)............  Revise this paragraph by adding the words
                                ``emission and operating'' to clarify
                                the limits that apply at all times.
40 CFR 63.7505(c)............  Revise this paragraph by adding the word
                                ``stack'' to clarify that the
                                performance testing referred to is
                                performance stack testing.
40 CFR 63.7510(a)(2)(ii).....  Revise this paragraph to clarify our
                                intent on fuel type for the analysis
                                requirements for gaseous fuels.
40 CFR 63.7510(a)............  Revise this paragraph by adding the word
                                ``stack'' to clarify that the
                                performance tests referred to are
                                performance stack test.
40 CFR 63.7510(c)............  Revise this paragraph to correct the
                                reference to tables 1 and 2, not 12.
40 CFR 63.7510(e)............  Revise this paragraph to remove reference
                                to paragraph (j) for the one-time energy
                                assessment because paragraph (j) only
                                repeat the compliance date as indicated
                                in paragraph (e) and to pluralize the
                                word ``demonstration.''
40 CFR 63.7510(g)............  Revise this paragraph to correct the
                                references to 40 CFR 63.7515(d), not 40
                                CFR 63.7540(a) to clarify the
                                appropriate schedule for conducting
                                periodic tune-ups.
40 CFR 63.7510(i)............  Revise this paragraph to correctly list
                                the initial compliance date (January 31,
                                2016).
40 CFR 63.7510(k)............  Add this paragraph to clarify the
                                appropriate schedule for conducting
                                performance tests after a switch in
                                subcategory.
40 CFR 63.7515(d)............  Revise this paragraph to clarify that the
                                first annual, biennial, or 5-year tune-
                                up must be no later than 13 months, 25
                                months, or 61 months, respectively,
                                either after April 1, 2013, or the
                                initial startup of the new or
                                reconstructed affected source, whichever
                                is later.
40 CFR 63.7515(h)............  Revise this paragraph to clarify that
                                ``performance tests'' refers to both
                                stack tests and fuel analyses.
40 CFR 63.7521(a)............  Revise this paragraph to clarify that
                                gaseous and liquid fuels are not exempt
                                from the sampling requirements in Table
                                6 of the rule.
40 CFR 63.7521(c)(1)(ii).....  Revise this paragraph to remove the
                                requirement to collect monthly samples
                                at 10-day intervals because it is
                                inconsistent with the requirement for
                                monthly fuel analysis in 40 CFR
                                63.7515(e).
40 CFR 63.7521(f)............  Revise this paragraph to clarify that the
                                two methods listed in Table 6 for
                                determining the mercury concentration
                                for other gas 1 fuels are alternatives.
40 CFR 63.7521(g)............  Revise this paragraph to remove the
                                requirement to submit for review and
                                approval a site-specific fuel analysis
                                plan for other gas 1 fuels because
                                paragraph (g)(1) requires the plan to be
                                submitted for review and approval only
                                if an alternative analytical method
                                other than those required by Table 6 is
                                intended to be used.
40 CFR 63.7521(h)............  Revise this paragraph to remove the
                                reference to sampling procedures listed
                                in Table 6 because there are no sampling
                                procedures listed in Table 6 for gaseous
                                fuel.
40 CFR 63.7522(c)............  Revise this paragraph by changing wording
                                from ``January 31, 2013'' (publication
                                date of the amendments) to ``April 1,
                                2013'' (the effective date of the
                                amendments.
40 CFR 63.7522(d)............  Revise this paragraph by changing wording
                                from ``operating'' to ``subject to
                                numeric emission limits'' to clarify
                                that the numeric emission limits do not
                                apply during startup and shutdown
                                periods.
40 CFR 63.7522(j)(1).........  Revise Equation 6 to delete ``nanograms
                                per dry standard cubic meter (ng/dscm)''
                                from both EN and Eli since there are not
                                numeric emission limits for dioxin.

40 CFR 63.7525(a)............  Revise the paragraph to clarify that the
                                procedures for installing oxygen
                                analyzer system or CO CEMS do not
                                include paragraph (a)(7) because (a)(7)
                                does not require the installation of an
                                oxygen trim system.
40 CFR 63.7525(a), (a)(1),     Revise these paragraphs to clarify that
 (a)(2), (a)(3), and (a)(5).    carbon dioxide may be used as an
                                alternative to using oxygen in
                                correcting the measured CO CEMS data
                                without petitioning for an alternative
                                monitoring procedure.
40 CFR 63.7525(a)(7).........  Revise this paragraph to clarify the
                                oxygen set point for a source not
                                required to conduct a CO performance
                                test.
40 CFR 63.7525(b) and (b)(1).  Remove the word ``certify'' because there
                                is no certification procedure for PM
                                CPMS.
40 CFR 63.7525(b)(1)(iii)....  Revise this paragraph to clarify that the
                                0.5 milligram per actual cubic meter is
                                the detection limit.
40 CFR 63.7525(g)(3).........  Revise this paragraph to clarify that the
                                pH monitor is to be calibrated each day
                                and not performance evaluated which is
                                covered in 40 CFR 63.7525(g)(4).
40 CFR 63.7525(m)............  Revise this paragraph to clarify that 40
                                CFR 63.7525(m) is only applicable if the
                                source elects to use an SO2 CEMS to
                                demonstrate compliance with the HCl
                                emission limit and to clarify that the
                                SO2 CEMS can be certified according to
                                either part 60 or part 75.
40 CFR 63.7530...............  Revise equations 7, 8, and 9 to clarify
                                that for ``Qi'' the highest content of
                                chlorine, mercury, and TSM is used only
                                for initial compliance and the actual
                                fraction is used for continuous
                                compliance demonstration.
40 CFR 63.7530(a)............  Revise this paragraph to clarify which
                                fuels are exempt from analysis by cross-
                                referencing 40 CFR 63.7510(a)(2),
                                instead of only 40 CFR 63.7510(a)(2)
                                (i).
40 CFR 63.7530(b)............  Revise this paragraph by adding the word
                                ``stack'' to clarify that the
                                performance testing referred to is
                                performance stack testing.
40 CFR 63.7530(b)(4)(iii) to   Revise the numbering of these paragraphs
 (viii).                        to correct sequence.
40 CFR 63.7530(c)(3).........  Revise the reference to Equation 11 to be
                                Equation 15, to accommodate the change
                                in numbering of equations.
40 CFR 63.7530(c)(4).........  Revise the reference to Equation 11 to be
                                Equation 15, to accommodate the change
                                in numbering of equations.
40 CFR 63.7530(c)(5).........  Revise the reference to Equation 11 to be
                                Equation 15, to accommodate the change
                                in numbering of equations.
40 CFR 63.7530(d)............  Amend this paragraph to clarify that the
                                requirement to include a signed
                                statement that the tune-up was conducted
                                is applicable to all existing units.
40 CFR 63.7530(e)............  Amend this paragraph to clarify that the
                                energy assessment is also considered to
                                have been completed if the maximum
                                number of on-site technical hours
                                specified in the definition of energy
                                assessment applicable to the facility
                                has been expended.
40 CFR 63.7530(h)............  Revise this paragraph to clarify that
                                both items 5 and 6 of Table 3 apply
                                during periods of startup and shutdown.
40 CFR 63.7530(i)(3).........  Revise this paragraph to read ``maximum''
                                instead of ``minimum'' to be consistent
                                with item 10 of Table 4 to subpart
                                DDDDD.
40 CFR 63.7533(e)............  Revise this paragraph by changing wording
                                from ``operating'' to ``subject to
                                numeric emission limits'' to clarify
                                that the numeric emission limits do not
                                apply during startup and shutdown
                                periods.
40 CFR 63.7535(c)............  Amend this paragraph to clarify that data
                                recorded during periods of startup and
                                shutdown may not be used to report
                                emissions or operating levels.
40 CFR 63.7535(d)............  Amend this paragraph to clarify that data
                                recorded during periods of startup and
                                shutdown may not be used to report
                                emissions or operating levels and that
                                the report for reporting periods when
                                the monitoring system is out of control
                                is the facility's ``semi-annual''
                                report.
40 CFR 63.7540(a)(2).........  Revise the reference to 40 CFR 63.7550(c)
                                to 40 CFR 63.7555(d).
40 CFR 63.7540(a)(3) and       Revise the reference to Equation 12 to
 (a)(3)(iii).                   Equation 16, to accommodate the change
                                in numbering of equations.
40 CFR 63.7540(a)(5) and       Revise the reference to Equation 13 to
 (a)(5)(iii).                   Equation 17, to accommodate the change
                                in numbering of equations.
40 CFR 63.7540(a)(8)(ii).....  Revise this paragraph by changing wording
                                from ``operating'' to ``subject to
                                numeric emission limits'' to clarify
                                that the numeric emission limits do not
                                apply during startup and shutdown
                                periods.
40 CFR 63.7540(a)(10)........  Amend this paragraph to clarify that the
                                tune-up must be conducted while burning
                                the type of fuel that provided the
                                majority of the heat input over the 12
                                months prior to the tune-up.
40 CFR 63.7540(a)(10)(vi)....  Revise paragraph to remove the word
                                ``annual'' because not all facilities
                                will necessarily be subject to an annual
                                tune-up requirement.
40 CFR 63.7540(a)(17) and      Revise the reference to Equation 14 to
 (a)(17)(iii).                  Equation 18, to accommodate the change
                                in numbering of equations.
40 CFR 63.7540(a)(19)(iii)...  Revise the reference from paragraph (i)
                                to paragraph (v).
40 CFR 63.7540(d)............  Revise the reference to item 5 of Table 3
                                to items 5 and 6 of Table 3 to
                                accommodate the splitting of the work
                                practice for startup and shutdown into
                                two separate items in Table 3.
40 CFR 63.7545(e)(8)(i)......  Revise this paragraph by changing the
                                wording from ``complies with'' to
                                ``completed'' to add clarity.
40 CFR 63.7545(h)............  Revise this paragraph to clarify the
                                paragraph also applies to process
                                heaters.
40 CFR 63.7550(b)............  Revise this paragraph to clarify that
                                units subject only to both the energy
                                assessment and tune-up requirements may
                                submit only an annual, biennial, or 5-
                                year compliance report.
40 CFR 63.7550(b)(1), (b)(2),  Revise these paragraphs to add the word
 (b)(3), and (b)(4).            ``semi-annual'' to clarify that the
                                compliance report initially discussed in
                                each paragraph is the semi-annual report
                                required for units subject to emission
                                limits.
40 CFR 63.7550(b)(1).........  Revise this paragraph to change the
                                reporting period end dates to be
                                consistent with the dates in 40 CFR
                                63.7550(b)(3).
40 CFR 63.7550 (c)(1)........  Revise this paragraph to remove the word
                                ``a,'' to change the wording from
                                ``they'' to ``you'' and to add reference
                                to 40 CFR 63.7550(c)(5)(xvii).
40 CFR 63.7550 (c)(2) and      Revise these paragraphs to add reference
 (c)(3).                        to 40 CFR 63.7550(c)(5)(xvii).
40 CFR 63.7550 (c)(3)........  Revise this paragraph to add reference to
                                40 CFR 63.7550(c)(5)(viii).
40 CFR 63.7550 (c)(2), (c)(3)  Revise these paragraphs to change the
 and (c)(4).                    wording from ``a facility is'' to ``you
                                are'' and ``they'' to ``you.''
40 CFR 63.7550 (c)(4)........  Revise the paragraph to include reference
                                to paragraph (c)(5)(xii).

40 CFR 63.7550(c)(5)(viii)...  Revise the reference to Equation 12 to
                                Equation 16, the reference to Equation
                                13 to Equation 17, and the reference to
                                Equation 14 to Equation 18, to
                                accommodate the change in numbering of
                                equations.
40 CFR 63.7550(d)............  Revise this paragraph to clarify that
                                deviations from the work practice
                                standards for periods of startup and
                                shutdown must also be included in the
                                compliance report.
40 CFR 63.7550(h)............  Revise the paragraph to update electronic
                                reporting requirements.
40 CFR 63.7555(a)(3).........  Redesignating paragraph 63.7550(d)(3) as
                                new paragraph 63.7550(a)(3) because
                                limited use units are not subject to
                                emission limits.
40 CFR 63.7555(d)(4).........  Change the reference to Equation 12 to
                                Equation 16, to accommodate the change
                                in numbering of equations.
40 CFR 63.7555(d)(5).........  Change the reference to Equation 13 to
                                Equation 17, to accommodate the change
                                in numbering of equations.
40 CFR 63.7555(d)(9).........  Change the reference to Equation 14 to
                                Equation 18, to accommodate the change
                                in numbering of equations.
40 CFR 63.7555(i) and (j)....  Delete paragraphs because paragraphs (i)
                                and (j) are identical to paragraphs
                                (d)(10) and (d)(11) to be consistent
                                with the intent of the amendments to
                                limit these reporting requirements to
                                units subject to emission limits.
40 CFR 63.7575...............  Revise the definition of ``Coal'' to
                                clarify that coal derived liquids are
                                considered to be a liquid fuel type.
                               Add new definition of ``Fossil fuel'' to
                                clarify what is meant by ``fossil fuel''
                                in the definition of ``Electric utility
                                steam generating unit.''
                               Revise the definition of ``Limited-use
                                boiler or process heater'' to remove the
                                word ``average'' to eliminate confusion
                                regarding its use in the definition and
                                maintain consistent terminology within
                                the subpart.
                               Revise the definition of ``Load
                                fraction'' to clarify how load fraction
                                is determined for a boiler or process
                                heater cofiring natural gas.
                               Revise the definition of ``Oxygen trim
                                system'' to include draft controller and
                                to clarify that it is a system that
                                maintains the desired excess air level
                                over the operating load range.
                               Revise the definition of ``Steam output''
                                to clarify how steam output is
                                determined for multi-function units and
                                units supplying steam to a common
                                header.
                               Revise the definition of ``Temporary
                                boiler'' to clarify that the definition
                                is also applicable to process heaters.
Table 1 to subpart DDDDD.....  Revise the subcategory ``Stokers designed
                                to burn coal/solid fossil fuel'' to
                                clarify that the subcategory includes
                                ``other combustors'' consistent with the
                                stokers designed to burn biomass
                                subcategories.
                               Add footnote ``d'' to clarify that carbon
                                dioxide may be used as an alternative to
                                using oxygen in correcting the measured
                                CO CEMS data without petitioning for an
                                alternative monitoring procedure.
Table 2 to subpart DDDDD.....  Revise the subcategory ``Stokers designed
                                to burn coal/solid fossil fuel'' to
                                clarify that the subcategory includes
                                ``other combustors'' consistent with the
                                stokers designed to burn biomass
                                subcategories.
                               Revise the CO emission limit for hybrid
                                suspension grate units to account for a
                                conversion error in the emission
                                database that inadvertently resulted in
                                a source incorrectly being a best
                                performing unit.
                               Revise items 14.b and 16.b to add the
                                reference to footnote ``a.''
                               Add footnote ``c'' to clarify that carbon
                                dioxide may be used as an alternative to
                                using oxygen in correcting the measured
                                CO CEMS data without petitioning for an
                                alternative monitoring procedure.
Table 3 to subpart DDDDD.....  Revise item 4 to clarify that
                                ``operates'' does not require the energy
                                management program to be implemented in
                                perpetuity and that an energy management
                                program developed according to ENERGY
                                STAR guidelines would also satisfy the
                                requirement.
                               Revise item 4e to read ``program''
                                instead of ``practices'' to be
                                consistent with the definition of
                                ``Energy management program'' in Sec.
                                63.7575.
Table 4 to subpart DDDDD.....  Revise certain items in the table to
                                clarify the applicability of the
                                parameter operating limits also apply to
                                process heaters.
                               Revise item 4 to clarify that item 4.a.
                                is applicable to dry ESP and item 4.b.
                                is applicable to wet ESP systems.
Table 5 to subpart DDDDD.....  Revise the heading of the third column to
                                clarify that the requirement to use a
                                specified method may not be appropriate
                                in all cases.
                               Add the missing footnote ``\a\
                                Incorporated by reference, see 40 CFR
                                63.14''
Table 6 to subpart DDDDD.....  Revise items 1, 2, and 4 to remove
                                reference to the equations cited in 40
                                CFR 63.7530 for demonstrating only
                                initial compliance.
                               Revise items 1.c, 2.c, and 4.c to remove
                                the listed method for liquid samples to
                                be consistent with 40 CFR 63.7521(a).
                               Revise item 3 to clarify that the two
                                methods listed are alternatives.
                               Revise the title to item 4 to remove
                                ``for solid fuels'' to clarify that item
                                4. is applicable to also liquid fuel
                                types.
Table 7 to subpart DDDDD.....  Revise item 1.a.i.(1) to clarify that TSM
                                performance test are also included.
                               Revise items 2.a.i. and 2.a.i.(1) to
                                remove ``pressure drop'' to be
                                consistent with 40 CFR 63.7530(b).
                               Revise items 2.b.i.(1)(c) and
                                3.a.i.(1)(c) to clarify that ``load
                                fraction'' is as defined in 40 CFR
                                63.7575.
                               Revise item 2.c.i(1)(b) to read
                                ``highest'' instead of ``lowest'' to be
                                consistent with item 10 of Table 4 to
                                subpart DDDDD.
                               Revise item 4 to read ``Carbon monoxide
                                for which compliance is demonstrated by
                                a performance test'' to clarify that
                                this operating limit is not applicable
                                for source complying with the CO CEMS
                                based limits.
Table 8 to subpart DDDDD.....  Revise item 3 to change the reference to
                                40 CFR 63.7540(a)(9) to 40 CFR
                                63.7540(a)(7).
                               Revise item 9.a to change the reference
                                to 40 CFR 63.7525(a)(2) to 40 CFR
                                63.7525(a)(7).
                               Revise item 11.c to read ``highest''
                                instead of ``minimum'' to be consistent
                                with item 10 of Table 4 to subpart
                                DDDDD.
                               Revise the operating load compliance
                                provisions (item 10) to be consistent
                                with 40 CFR 63.7525(d).
Table 9 to subpart DDDDD.....  Revise Table 9 to subpart DDDDD to
                                clarify that it is deviations from the
                                work practice standards for periods of
                                startup and shutdown that are to be
                                included.
Table 11 to subpart DDDDD....  Revise Table 11 to subpart DDDDD to be
                                consistent with the final amended rule
                                because of incorrect amendatory
                                instructions.
Table 12 to subpart DDDDD....  Revise Table 12 to subpart DDDDD to be
                                consistent with the final amended rule
                                because of incorrect amendatory
                                instructions.
------------------------------------------------------------------------

V. Affirmative Defense for Violation of Emission Standards During
Malfunction

    In several prior CAA section 112 and CAA section 129 rules,
including this rule, the EPA had included an affirmative defense to
civil penalties for violations caused by malfunctions in an effort to
create a system that incorporates some flexibility, recognizing that
there is a tension, inherent in many types of air regulation, to ensure
adequate compliance while simultaneously recognizing that despite the
most diligent of efforts, emission standards may be violated under
circumstances entirely beyond the control of the source. Although the
EPA recognized that its case-by-case enforcement discretion provides
sufficient flexibility in these circumstances, it included the
affirmative defense to provide a more formalized approach and more
regulatory clarity. See Weyerhaeuser Co. v. Costle, 590 F.2d 1011,
1057-58 (D.C. Cir. 1978) (holding that an informal case-by-case
enforcement discretion approach is adequate); but see Marathon Oil Co.
v. EPA, 564 F.2d 1253, 1272-73 (9th Cir. 1977) (requiring a more
formalized approach to consideration of ``upsets beyond the control of
the permit holder.''). Under the EPA's regulatory affirmative defense
provisions, if a source could demonstrate in a judicial or
administrative proceeding that it had met the requirements of the
affirmative defense in the regulation, civil penalties would not be
assessed. Recently, the United States Court of Appeals for the District
of Columbia Circuit vacated an affirmative defense in one of the EPA's
CAA section 112 regulations. NRDC v. EPA, 749 F.3d 1055 (D.C. Cir.,
2014) (vacating affirmative defense provisions in CAA section 112 rule
establishing emission standards for Portland cement kilns). The court
found that the EPA lacked authority to establish an affirmative defense
for private civil suits and held that under the CAA, the authority to
determine civil penalty amounts in such cases lies exclusively with the
courts, not the EPA. Specifically, the court found: ``As the language
of the statute makes clear, the courts determine, on a case-by-case
basis, whether civil penalties are `appropriate.' '' See NRDC, 2014
U.S. App. LEXIS 7281 at *21 (``[U]nder this statute, deciding whether
penalties are `appropriate' . . . is a job for the courts, not EPA.'').
In light of NRDC, the EPA is proposing to remove the regulatory
affirmative defense provision in the current rule.
    In the event that a source fails to comply with the applicable CAA
section 112 standards as a result of a malfunction event, the EPA would
determine an appropriate response based on, among other things, the
good faith efforts of the source to minimize emissions during
malfunction periods, including preventative and corrective actions, as
well as root cause analyses to ascertain and rectify excess emissions.
The EPA would also consider whether the source's failure to comply with
the CAA section 112 standard was, in fact, ``sudden, infrequent, not
reasonably preventable'' and was not instead ``caused in part by poor
maintenance or careless operation.'' 40 CFR 63.2 (definition of
malfunction).
    Further, to the extent the EPA files an enforcement action against
a source for violation of an emission standard, the source can raise
any and all defenses in that enforcement action and the federal
district court will determine what, if any, relief is appropriate. The
same is true for citizen enforcement actions. Cf. NRDC at 1064
(arguments that violation was caused by unavoidable technology failure
can be made to the courts in future civil cases when the issue arises).
Similarly, the presiding officer in an administrative proceeding can
consider any defense raised and determine whether administrative
penalties are appropriate.

VI. Solicitation of Public Comment and Participation

    The EPA seeks full public participation in arriving at its final
decisions. At this time, the EPA is only proposing alternatives to the
final rule's definitions of startup and shutdown, the work practices
that apply during those periods, and recordkeeping requirements for
startup periods. The EPA is not proposing any other specific revisions
to the reconsideration issues. However, the EPA requests public comment
on the three issues under reconsideration.
    Additionally, the EPA is making certain clarifying changes and
corrections to the final rule. We are soliciting comments on whether
the proposed changes provide the intended accuracy, clarity and
consistency. The EPA is also proposing to amend the final rule by
removing the affirmative defense provision. We request comment on all
of these proposed changes.
    The EPA is seeking comment only on the specific three issues, the
clarifying changes and corrections, and the amendments described in
this notice. The EPA will not respond to any comments addressing any
other issues or any other provisions of the final rule or any other
rule.

VII. Statutory and Executive Order Reviews

    Additional information about these statutes and Executive Orders
can be found at http://www2.epa.gov/laws-regulations/laws-and-executive-orders.

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.

B. Paperwork Reduction Act (PRA)

    This action does not impose any new information collection burden
under PRA. With this action, the EPA is seeking additional comments on
three aspects of the final amended NESHAP for industrial, commercial,
and institutional boilers and process heaters located at major sources
of HAP with proposing only minor changes to the rule to correct and
clarify implementation issues raised by stakeholders. However, the
Office of Management and Budget (OMB) has previously approved the
information collection requirements contained in the existing
regulations under the provisions of the Paperwork Reduction Act, 44
U.S.C. 3501 et seq. and has assigned OMB control number 2060-0551. The
OMB control numbers for the EPA's regulations in 40 CFR are listed in
40 CFR part 9.

C. Regulatory Flexibility Act (RFA)

    I certify that this action will not have a significant economic
impact on a substantial number of small entities under the RFA. This
action will not impose any requirements on small entities. This action
seeks comment on three aspects of the final NESHAP for industrial,
commercial, and institutional boilers and process heaters located at
major sources of HAP as well as proposing minor changes to the rule to
correct and clarify implementation issues raised by stakeholders.
    We continue to be interested in the potential impacts of the
proposed rule on small entities and welcome comments on issues related
to such impacts.

D. Unfunded Mandates Reform Act (UMRA)

    This action does not contain any unfunded mandates as described in
UMRA, 2 U.S.C. 1531-1538. The action imposes no enforceable duty on any

state, local or tribal governments or the private sector.
    This action seeks comment on three aspects of the final NESHAP for
industrial, commercial, and institutional boilers and process heaters
located at major sources of HAP with proposing minor changes to the
rule to correct and clarify implementation issues raised by
stakeholders.

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. This
action seeks comment on three aspects of the final NESHAP for
industrial, commercial, and institutional boilers and process heaters
located at major sources of HAP without proposing any changes to the
rule. Thus, Executive Order 13132 does not apply to this action.
    In the spirit of Executive Order 13132, and consistent with EPA
policy to promote communications between EPA and state and local
governments, the EPA specifically solicits comment on this proposed
action from state and local officials.

F. Executive Order 13175: Consultation and Coordination With Indian
Tribal Governments

    This action does not have tribal implications, as specified in
Executive Order 13175. This action will not have substantial direct
effects on tribal governments, 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, as
specified in Executive Order 13175. Thus, Executive Order 13175 does
not apply to this action.
    The EPA specifically solicits additional comment on this proposed
action from tribal officials.

G. Executive Order 13045: Protection of Children From Environmental
Health Risks and Safety Risks

    The EPA interprets Executive Order 13045 as applying to those
regulatory actions that concern environmental health or safety risks
that the 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 a ``significant energy action'' because it is
not likely to have a significant adverse effect on the supply,
distribution or use of energy.

I. National Technology Transfer and Advancement Act

    Section 12(d) of the National Technology Transfer and Advancement
Act (NTTAA) of 1995 (Pub. L. 104-113, Section 12(d), 15 U.S.C. 272
note) directs the EPA to use voluntary consensus standards (VCS) in its
regulatory activities, unless to do so would be inconsistent with
applicable law or otherwise impractical. The VCS are technical
standards (e.g., materials specifications, test methods, sampling
procedures and business practices) that are developed or adopted by VCS
bodies. The NTTAA directs the EPA to provide Congress, through OMB,
explanations when the agency does not use available and applicable VCS.
    This action does not involve technical standards. Therefore, the
EPA did not consider the use of any VCS.

J. Executive Order 12898: Federal Actions To Address Environmental
Justice in Minority Populations and Low-Income Populations

    Executive Order 12898 (59 FR 7629, February 16, 1994) establishes
federal executive policy on environmental justice. Its main provision
directs federal agencies, to the greatest extent practicable and
permitted by law, to make environmental justice part of their mission
by identifying and addressing, as appropriate, disproportionately high
and adverse human health or environmental effects of their programs,
policies, and activities on minority populations and low-income
populations in the United States.
    The EPA has determined that this proposed rule will not have
disproportionately high and adverse human health or environmental
effects on minority or low-income populations because it does not
affect the level of protection provided to human health or the
environment. This action seeks comment on three aspects of the final
NESHAP for industrial, commercial, and institutional boilers and
process heaters located at major sources of HAP with proposing minor
changes to the rule to correct and clarify implementation issues raised
by stakeholders.

List of Subjects in 40 CFR Part 63

    Environmental Protect, Administrative practice and procedure, Air
pollution control, Hazardous substances, Intergovernmental relations,
Reporting and recordkeeping requirements.

    Dated: December 1, 2014.
Gina McCarthy,
Administrator.
    For the reasons cited in the preamble, title 40, chapter I, part 63
of the Code of Federal Regulations is proposed to be amended as
follows:

PART 63-- NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS
FOR SOURCE CATEGORIES

0
1. The authority for part 63 continues to read as follows:

    Authority: 42 U.S.C. 7401, et seq.

Subpart DDDDD--[Amended]

0
2. Section 63.7491 is amended by:
0
a. Revising paragraphs (a), (j) and (l).
0
b. Adding paragraph (n).
    The revisions and addition read as follows:

Sec.  63.7491  Are any boilers or process heaters not subject to this
subpart?

* * * * *
    (a) An electric utility steam generating unit (EGU) covered by
subpart UUUUU of this part or a natural gas-fired EGU as defined in
subpart UUUUU of this part firing at least 90 percent natural gas on an
annual heat input basis.
* * * * *
    (j) Temporary boilers and process heaters as defined in this
subpart.
* * * * *
    (l) Any boiler or process heater specifically listed as an affected
source in any standard(s) established under section 129 of the Clean
Air Act.
* * * * *
    (n) Residential boilers as defined in this subpart.
0
3. Section 63.7495 is amended by:
0
a. Revising paragraphs (a) and (e).
0
b. Adding paragraphs (h) and (i).
    The revisions and additions read as follows:

Sec.  63.7495  When do I have to comply with this subpart?

    (a) If you have a new or reconstructed boiler or process heater,
you must comply with this subpart by April 1, 2013, or upon startup of
your boiler or process heater, whichever is later.
* * * * *
    (e) If you own or operate an industrial, commercial, or
institutional

boiler or process heater and would be subject to this subpart except
for the exemption in Sec.  63.7491(l) for commercial and industrial
solid waste incineration units covered by part 60, subpart CCCC or
subpart DDDD, and you cease combusting solid waste, you must be in
compliance with this subpart and are no longer subject to part 60,
subparts CCCC or DDDD beginning on the effective date of the switch as
identified under the provisions of Sec.  60.2145(a)(2) and (3) or Sec.
60.2710(a)(2) and (3).
* * * * *
    (h) If you own or operate an existing industrial, commercial, or
institutional boiler or process heater and have switch fuels or made a
physical change to the boiler or process heater that resulted in the
applicability of a different subcategory after January 31, 2016, you
must be in compliance with the applicable existing source provisions of
this subpart on the effective date of the fuel switch or physical
change.
    (i) If you own or operate a new industrial, commercial, or
institutional boiler or process heater and have switch fuels or made a
physical change to the boiler or process heater that resulted in the
applicability of a different subcategory, you must be in compliance
with the applicable new source provisions of this subpart on the
effective date of the fuel switch or physical change.
* * * * *
0
4. Section 63.7500 is amended by revising paragraphs (a)(1) and (f) to
read as follows:

Sec.  63.7500  What emission limitations, work practice standards, and
operating limits must I meet?

    (a) * * *
    (1) You must meet each emission limit and work practice standard in
Tables 1 through 3, and 11 through 13 to this subpart that applies to
your boiler or process heater, for each boiler or process heater at
your source, except as provided under Sec.  63.7522. The output-based
emission limits, in units of pounds per million Btu of steam output, in
Tables 1 or 2 to this subpart are an alternative applicable only to
boilers and process heaters that generate either steam, cogenerate
steam with electricity, or both. The output-based emission limits, in
units of pounds per megawatt-hour, in Tables 1 or 2 to this subpart are
an alternative applicable only to boilers that generate only
electricity. Boilers that perform multiple functions (cogeneration and
electricity generation) or supply steam to common heaters would
calculate a total steam energy output using equation 21 of Sec.
63.7575 to demonstrate compliance with the output-based emission
limits, in units of pounds per million Btu of steam output, in Tables 1
or 2 to this subpart. If you operate a new boiler or process heater,
you can choose to comply with alternative limits as discussed in
paragraphs (a)(1)(i) through (a)(1)(iii) of this section, but on or
after January 31, 2016, you must comply with the emission limits in
Table 1 to this subpart.
    (i) If your boiler or process heater commenced construction or
reconstruction after June 4, 2010 and before May 20, 2011, you may
comply with the emission limits in Table 1 or 11 to this subpart until
January 31, 2016.
    (ii) If your boiler or process heater commenced construction or
reconstruction on or after May 20, 2011 and before December 23, 2011,
you may comply with the emission limits in Table 1 or 12 to this
subpart until January 31, 2016.
    (iii) If your boiler or process heater commenced construction or
reconstruction on or after December 23, 2011 and before April 1, 2013,
you may comply with the emission limits in Table 1 or 13 to this
subpart until January 31, 2016.
* * * * *
    (f) These standards apply at all times the affected unit is
operating, except during periods of startup and shutdown during which
time you must comply only with items 5 and 6 of Table 3 to this
subpart.
* * * * *

Sec.  63.7501  [Removed]

0
5. Section 63.7501 is removed.
0
6. Section 63.7505 is amended by revising paragraphs (a) and (c) and
adding paragraph (e) to read as follows:

Sec.  63.7505  What are my general requirements for complying with this
subpart?

    (a) You must be in compliance with the emission limits, work
practice standards, and operating limits in this subpart. These
emission and operating limits apply to you at all times the affected
unit is operating except for the periods noted in Sec.  63.7500(f).
* * * * *
    (c) You must demonstrate compliance with all applicable emission
limits using performance stack testing, fuel analysis, or continuous
monitoring systems (CMS), including a continuous emission monitoring
system (CEMS), continuous opacity monitoring system (COMS), continuous
parameter monitoring system (CPMS), or particulate matter continuous
parameter monitoring system (PM CPMS), where applicable. You may
demonstrate compliance with the applicable emission limit for hydrogen
chloride (HCl), mercury, or total selected metals (TSM) using fuel
analysis if the emission rate calculated according to Sec.  63.7530(c)
is less than the applicable emission limit. (For gaseous fuels, you may
not use fuel analyses to comply with the TSM alternative standard or
the HCl standard.) Otherwise, you must demonstrate compliance for HCl,
mercury, or TSM using performance stack testing, if subject to an
applicable emission limit listed in Tables 1, 2, or 11 through 13 to
this subpart.
* * * * *
    (e) If you have an applicable emission limit, you must develop a
site-specific monitoring plan for work practice monitoring during
startup periods according to the requirements in Table 3 to this
subpart. The site-specific monitoring plan for startup periods must be
maintained onsite and available upon request for public inspection.
* * * * *
0
7. Section 63.7510 is amended by:
0
a. Revising paragraphs (a) introductory text, (a)(2)(ii), (c), (e),
(g), and (i) .
0
b. Adding paragraph (k).
    The revisions and addition read as follows:

Sec.  63.7510  What are my initial compliance requirements and by what
date must I conduct them?

    (a) For each boiler or process heater that is required or that you
elect to demonstrate compliance with any of the applicable emission
limits in Tables 1 or 2 or 11 through 13 of this subpart through
performance (stack) testing, your initial compliance requirements
include all the following:
* * * * *
    (2) * * *
    (ii) When natural gas, refinery gas, or other Gas 1 fuels are co-
fired with other fuels, you are not required to conduct a fuel analysis
of those Gas 1 fuels according to Sec.  63.7521 and Table 6 to this
subpart. If gaseous fuels other than natural gas, refinery gas, or
other Gas 1 fuels are co-fired with other fuels and those non-Gas 1
gaseous fuels are subject to another subpart of this part, part 60,
part 61, or part 65, you are not required to conduct a fuel analysis of
those non-Gas 1 fuels according to Sec.  63.7521 and Table 6 to this
subpart.
* * * * *
    (c) If your boiler or process heater is subject to a carbon
monoxide (CO) limit, your initial compliance demonstration for CO is to
conduct a performance test

for CO according to Table 5 to this subpart or conduct a performance
evaluation of your continuous CO monitor, if applicable, according to
Sec.  63.7525(a). Boilers and process heaters that use a CO CEMS to
comply with the applicable alternative CO CEMS emission standard listed
in Tables 1, 2, or 11 through 13 to this subpart, as specified in Sec.
63.7525(a), are exempt from the initial CO performance testing and
oxygen concentration operating limit requirements specified in
paragraph (a) of this section.
* * * * *
    (e) For existing affected sources (as defined in Sec.  63.7490),
you must complete the initial compliance demonstrations, as specified
in paragraphs (a) through (d) of this section, no later than 180 days
after the compliance date that is specified for your source in Sec.
63.7495 and according to the applicable provisions in Sec.  63.7(a)(2)
as cited in Table 10 to this subpart, except as specified in paragraph
(j) of this section. You must complete an initial tune-up by following
the procedures described in Sec.  63.7540(a)(10)(i) through (vi) no
later than the compliance date specified in Sec.  63.7495, except as
specified in paragraph (j) of this section. You must complete the one-
time energy assessment specified in Table 3 to this subpart no later
than the compliance date specified in Sec.  63.7495.
* * * * *
    (g) For new or reconstructed affected sources (as defined in Sec.
63.7490), you must demonstrate initial compliance with the applicable
work practice standards in Table 3 to this subpart within the
applicable annual, biennial, or 5-year schedule as specified in Sec.
63.7515(d) following the initial compliance date specified in Sec.
63.7495(a). Thereafter, you are required to complete the applicable
annual, biennial, or 5-year tune-up as specified in Sec.  63.7515(d).
* * * * *
    (i) For an existing EGU that becomes subject after January 31,
2016, you must demonstrate compliance within 180 days after becoming an
affected source.
* * * * *
    (k) For affected sources, as defined in Sec.  63.7490, that switch
subcategory consistent with Sec.  63.7545(h) after the initial
compliance date, you must demonstrate compliance within 60 days of the
effective date of the switch, unless you had previously conducted your
compliance demonstration for this subcategory within the previous 12
months.
0
8. Section 63.7515 is amended by revising paragraphs (d) and (h) to
read as follows:

Sec.  63.7515  When must I conduct subsequent performance tests, fuel
analyses, or tune-ups?

* * * * *
    (d) If you are required to meet an applicable tune-up work practice
standard, you must conduct an annual, biennial, or 5-year performance
tune-up according to Sec.  63.7540(a)(10), (11), or (12), respectively.
Each annual tune-up specified in Sec.  63.7540(a)(10) must be no more
than 13 months after the previous tune-up. Each biennial tune-up
specified in Sec.  63.7540(a)(11) must be conducted no more than 25
months after the previous tune-up. Each 5-year tune-up specified in
Sec.  63.7540(a)(12) must be conducted no more than 61 months after the
previous tune-up. For a new or reconstructed affected source (as
defined in Sec.  63.7490), the first annual, biennial, or 5-year tune-
up must be no later than 13 months, 25 months, or 61 months,
respectively, after April 1, 2013 or the initial startup of the new or
reconstructed affected source, whichever is later.
* * * * *
    (h) If your affected boiler or process heater is in the unit
designed to burn light liquid subcategory and you combust ultra-low
sulfur liquid fuel, you do not need to conduct further performance
tests (stack tests or fuel analyses) if the pollutants measured during
the initial compliance performance tests meet the emission limits in
Tables 1 or 2 of this subpart providing you demonstrate ongoing
compliance with the emissions limits by monitoring and recording the
type of fuel combusted on a monthly basis. If you intend to use a fuel
other than ultra-low sulfur liquid fuel, natural gas, refinery gas, or
other gas 1 fuel, you must conduct new performance tests within 60 days
of burning the new fuel type.
* * * * *
0
9. Section 63.7521 is amended by:
0
a. Revising paragraph (a).
0
b. Revising paragraph (c)(1).
0
c. Revising paragraph (f) introductory text.
0
d. Revising paragraph (g) introductory text.
0
e. Revising paragraph (h).
    The revisions read as follows:

Sec.  63.7521  What fuel analyses, fuel specification, and procedures
must I use?

    (a) For solid and liquid fuels, you must conduct fuel analyses for
chloride and mercury according to the procedures in paragraphs (b)
through (e) of this section and Table 6 to this subpart, as applicable.
For solid fuels and liquid fuels, you must also conduct fuel analyses
for TSM if you are opting to comply with the TSM alternative standard.
For gas 2 (other) fuels, you must conduct fuel analyses for mercury
according to the procedures in paragraphs (b) through (e) of this
section and Table 6 to this subpart, as applicable. (For gaseous fuels,
you may not use fuel analyses to comply with the TSM alternative
standard or the HCl standard.) For purposes of complying with this
section, a fuel gas system that consists of multiple gaseous fuels
collected and mixed with each other is considered a single fuel type
and sampling and analysis is only required on the combined fuel gas
system that will feed the boiler or process heater. Sampling and
analysis of the individual gaseous streams prior to combining is not
required. You are not required to conduct fuel analyses for fuels used
for only startup, unit shutdown, and transient flame stability
purposes. You are required to conduct fuel analyses only for fuels and
units that are subject to emission limits for mercury, HCl, or TSM in
Tables 1 and 2 or 11 through 13 to this subpart. Gaseous and liquid
fuels are exempt from the sampling requirements in paragraphs (c) and
(d) of this section.
* * * * *
    (c) * * *
    (1) If sampling from a belt (or screw) feeder, collect fuel samples
according to paragraphs (c)(1)(i) and (ii) of this section.
    (i) Stop the belt and withdraw a 6-inch wide sample from the full
cross-section of the stopped belt to obtain a minimum two pounds of
sample. You must collect all the material (fines and coarse) in the
full cross-section. You must transfer the sample to a clean plastic
bag.
    (ii) Each composite sample will consist of a minimum of three
samples collected at approximately equal one-hour intervals during the
testing period for sampling during performance stack testing.
* * * * *
    (f) To demonstrate that a gaseous fuel other than natural gas or
refinery gas qualifies as an other gas 1 fuel, as defined in Sec.
63.7575, you must conduct a fuel specification analyses for mercury
according to the procedures in paragraphs (g) through (i) of this
section and Table 6 to this subpart, as applicable, except as specified
in paragraph (f)(1) through (4) of this section, or as an alternative
where fuel specification analysis is not practical,

you must measure mercury concentration in the exhaust gas when firing
only the gaseous fuel to be demonstrated as an other gas 1 fuel in the
boiler or process heater according to the procedures in Table 6 to this
subpart.
* * * * *
    (g) You must develop a site-specific fuel analysis plan for other
gas 1 fuels according to the following procedures and requirements in
paragraphs (g)(1) and (2) of this section.
* * * * *
    (h) You must obtain a single fuel sample for each fuel type for
fuel specification of gaseous fuels.
* * * * *
0
10. Section 63.7522 is amended by revising paragraphs (c), (d), (i),
and (j)(1) to read as follows:

Sec.  63.7522  Can I use emissions averaging to comply with this
subpart?

* * * * *
    (c) For each existing boiler or process heater in the averaging
group, the emission rate achieved during the initial compliance test
for the HAP being averaged must not exceed the emission level that was
being achieved on April 1, 2013 or the control technology employed
during the initial compliance test must not be less effective for the
HAP being averaged than the control technology employed on April 1,
2013.
    (d) The averaged emissions rate from the existing boilers and
process heaters participating in the emissions averaging option must
not exceed 90 percent of the limits in Table 2 to this subpart at all
times the affected units are subject to numeric emission limits
following the compliance date specified in Sec.  63.7495.
* * * * *
    (i) For a group of two or more existing units in the same
subcategory, each of which vents through a common emissions control
system to a common stack, that does not receive emissions from units in
other subcategories or categories, you may treat such averaging group
as a single existing unit for purposes of this subpart and comply with
the requirements of this subpart as if the group were a single unit.
    (j) * * *
    (1) Conduct performance tests according to procedures specified in
Sec.  63.7520 in the common stack if affected units from other
subcategories vent to the common stack. The emission limits that the
group must comply with are determined by the use of Equation 6 of this
section.
[GRAPHIC] [TIFF OMITTED] TP21JA15.000

Where:

En = HAP emission limit, pounds per million British thermal units
(lb/MMBtu) or parts per million (ppm).
ELi = Appropriate emission limit from Table 2 to this subpart for
unit i, in units of lb/MMBtu or ppm.
Hi = Heat input from unit i, MMBtu.

* * * * *
0
11. Section 63.7525 is amended by:
0
a. Revising paragraphs (a) introductory text, (a)(1), (a)(2)
introductory text, (a)(3), (a)(5), and (a)(7).
0
b. Revising paragraphs (b) introductory text and (b)(1).
0
c. Revising paragraph (g)(3).
0
d. Revising paragraphs (m) introductory text and (m)(2).
    The revisions to read as follows:

Sec.  63.7525  What are my monitoring, installation, operation, and
maintenance requirements?

    (a) If your boiler or process heater is subject to a CO emission
limit in Tables 1, 2, or 11 through 13 to this subpart, you must
install, operate, and maintain an oxygen analyzer system, as defined in
Sec.  63.7575, or install, certify, operate and maintain continuous
emission monitoring systems for CO and oxygen (or carbon dioxide
(CO2)) according to the procedures in paragraphs (a)(1)
through (6) of this section.
    (1) Install the CO CEMS and oxygen (or CO2) analyzer by
the compliance date specified in Sec.  63.7495. The CO and oxygen (or
CO2) levels shall be monitored at the same location at the
outlet of the boiler or process heater.
    (2) To demonstrate compliance with the applicable alternative CO
CEMS emission standard listed in Tables 1, 2, or 11 through 13 to this
subpart, you must install, certify, operate, and maintain a CO CEMS and
an oxygen analyzer according to the applicable procedures under
Performance Specification 4, 4A, or 4B at 40 CFR part 60, appendix B;
part 75 of this chapter (if an CO2 analyzer is used); the
site-specific monitoring plan developed according to Sec.  63.7505(d);
and the requirements in Sec.  63.7540(a)(8) and paragraph (a) of this
section. Any boiler or process heater that has a CO CEMS that is
compliant with Performance Specification 4, 4A, or 4B at 40 CFR part
60, appendix B, a site-specific monitoring plan developed according to
Sec.  63.7505(d), and the requirements in Sec.  63.7540(a)(8) and
paragraph (a) of this section must use the CO CEMS to comply with the
applicable alternative CO CEMS emission standard listed in Tables 1, 2,
or 11 through 13 to this subpart.
* * * * *
    (3) Complete a minimum of one cycle of CO and oxygen (or
CO2) CEMS operation (sampling, analyzing, and data
recording) for each successive 15-minute period. Collect CO and oxygen
(or CO2) data concurrently. Collect at least four CO and
oxygen (or CO2) CEMS data values representing the four 15-
minute periods in an hour, or at least two 15-minute data values during
an hour when CEMS calibration, quality assurance, or maintenance
activities are being performed.
* * * * *
    (5) Calculate one-hour arithmetic averages, corrected to 3 percent
oxygen (or corrected to an CO2 percentage determined to be
equivalent to 3 percent oxygen) from each hour of CO CEMS data in parts
per million CO concentration. The one-hour arithmetic averages required
shall be used to calculate the 30-day or 10-day rolling average
emissions. Use Equation 19-19 in section 12.4.1 of Method 19 of 40 CFR
part 60, appendix A-7 for calculating the average CO concentration from