[Federal Register Volume 79, Number 195 (Wednesday, October 8, 2014)]
[Rules and Regulations]
[Pages 60897-60935]
[FR Doc No: 2014-23099]

Vol. 79

Wednesday,

No. 195

October 8, 2014

Part II

 Environmental Protection Agency

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40 CFR Part 63

 National Emission Standards for Hazardous Air Pollutants: Generic
Maximum Achievable Control Technology Standards; and Manufacture of
Amino/Phenolic Resins; Final Rule

Federal Register / Vol. 79 , No. 195 / Wednesday, October 8, 2014 /
Rules and Regulations

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 63

[EPA-HQ-OAR-2012-0133; FRL-9916-90-OAR]
RIN 2060-AR49

National Emission Standards for Hazardous Air Pollutants: Generic
Maximum Achievable Control Technology Standards; and Manufacture of
Amino/Phenolic Resins

AGENCY: Environmental Protection Agency.

ACTION: Final rule.

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SUMMARY: This action finalizes the residual risk and technology review
(RTR) conducted for the Acrylic and Modacrylic Fibers Production,
Amino/Phenolic Resins Production and Polycarbonate Production source
categories regulated under national emission standards for hazardous
air pollutants (NESHAP). In addition, we are taking final action
addressing emissions during periods of startup, shutdown and
malfunction, and are adding standards for previously unregulated
hazardous air pollutant (HAP) emissions sources for certain emission
points. These changes include revisions made in response to comments
received on the proposed rule. These final amendments also include
clarifying provisions pertaining to open-ended valves and lines, adding
monitoring requirements for pressure relief devices and adding
requirements for electronic reporting of performance test results, as
proposed. We estimate that these final amendments will reduce HAP
emissions from these three source categories by a combined 137 tons per
year.

DATES: This final action is effective on October 8, 2014.

ADDRESSES: The Environmental Protection Agency (EPA) has established a
docket for this rulemaking under Docket ID No. EPA-HQ-OAR-2012-0133.
All documents in the docket are listed in the http://www.regulations.gov Web site. Although listed in the index, some
information is not publicly available, e.g., confidential business
information (CBI) or other information whose disclosure is restricted
by statute. Certain other material, such as copyrighted material, is
not placed on the Internet and will be publicly available only in hard
copy form. Publicly available docket materials are available either
electronically through http://www.regulations.gov or in hard copy at
the EPA Docket Center, WJC West Building, Room Number 3334, 1301
Constitution Ave. NW., Washington, DC. The Public Reading Room hours of
operation are 8:30 a.m. to 4:30 p.m. Eastern Standard Time (EST),
Monday through Friday. The telephone number for the Public Reading Room
is<PHONE_NUMBER>, and the telephone number for the Air and Radiation
Docket and Information Center is<PHONE_NUMBER>.

FOR FURTHER INFORMATION CONTACT: For questions about this final action,
contact Mr. Nick Parsons, Sector Policies and Programs Division (E143-
01), Office of Air Quality Planning and Standards (OAQPS), U.S.
Environmental Protection Agency, Research Triangle Park, North Carolina
27711; telephone number:<PHONE_NUMBER>; fax number:<PHONE_NUMBER>;
and email address<EMAIL_ADDRESS>For specific information
regarding the risk modeling methodology, contact Mr. Mark Morris,
Health and Environmental Impacts Division (C539-02), OAQPS, U.S.
Environmental Protection Agency, Research Triangle Park, North Carolina
27711; telephone number:<PHONE_NUMBER>; fax number:<PHONE_NUMBER>;
and email address<EMAIL_ADDRESS>For information about the
applicability of these three NESHAP to a particular entity, contact Ms.
Tavara Culpepper, Office of Enforcement and Compliance Assurance
(OECA), U.S. Environmental Protection Agency, Washington, DC 20004;
telephone number:<PHONE_NUMBER>; and email address:
<EMAIL_ADDRESS>
SUPPLEMENTARY INFORMATION:
    Acronyms and Abbreviations. The following acronyms and
abbreviations are used in this document.

AEGL acute exposure guideline levels
AMF Acrylic and Modacrylic Fibers Production
APPU amino/phenolic resin process unit
APR Amino/Phenolic Resins Production
CAA Clean Air Act
CBI Confidential Business Information
CDX Central Data Exchange
CEDRI Compliance and Emissions Data Reporting Interface
CFR Code of Federal Regulations
EJ environmental justice
EPA Environmental Protection Agency
ERT Electronic Reporting Tool
FR Federal Register
gal gallon
HAP hazardous air pollutants
HI hazard index
HON National Emission Standards for Organic Hazardous Air Pollutants
from the Synthetic Organic Chemical Manufacturing Industry
HQ hazard quotient
ICR Information Collection Request
kg kilogram
LDAR leak detection and repair
MACT maximum achievable control technology
Mg megagram
MIR maximum individual risk
MTVP maximum true vapor pressure
NAICS North American Industry Classification System
NEI National Emissions Inventory
NESHAP National Emission Standards for Hazardous Air Pollutants
NTTAA National Technology Transfer and Advancement Act
OAQPS Office of Air Quality Planning and Standards
OECA Office of Enforcement and Compliance Assurance
OMB Office of Management and Budget
PC Polycarbonate Production
ppm parts per million
PRD pressure relief device
psia pounds per square inch absolute
REL reference exposure level
RFA Regulatory Flexibility Act
RTR residual risk and technology review
SBA Small Business Administration
SSM startup, shutdown and malfunction
TOSHI target organ-specific hazard index
tpy tons per year
TTN Technology Transfer Network
UMRA Unfunded Mandates Reform Act
VCS voluntary consensus standards
VOC volatile organic compounds
WWW World Wide Web

    Background Information. On January 9, 2014, the EPA proposed
revisions to the Acrylic and Modacrylic Fibers Production, Amino/
Phenolic Resins Production and Polycarbonate Production NESHAP based on
our RTR. In this action, we are finalizing decisions and revisions for
the rules. We summarize some of the comments we timely received
regarding the proposed rule and provide our responses in this preamble.
A summary of the public comments on the proposal not presented in the
preamble and the EPA's responses to those comments is available in
Docket ID No. EPA-HQ-OAR-2012-0133. A ``track changes'' version of the
regulatory language that incorporates the changes in this action is
available in the docket.
    Organization of This Document. We provide the following outline to
assist in locating information in the preamble.

I. General Information
    A. Does this action apply to me?
    B. Where can I get a copy of this document and other related
information?
    C. Judicial Review
II. Background
    A. What is the statutory authority for this action?
    B. Acrylic and Modacrylic Fibers Production (AMF)
    C. Amino/Phenolic Resins Production (APR)
    D. Polycarbonate Production
III. What is included in this final rule?
    A. Acrylic and Modacrylic Fibers Production
    B. Amino/Phenolic Resins Production

    C. Polycarbonate Production
    D. What are the final rule amendments for all three source
categories addressing emissions during periods of startup, shutdown
and malfunction?
    E. What other changes have been made to all three NESHAP?
    F. What are the effective and compliance dates of the standards
for all three source categories?
IV. What is the rationale for our final decisions and amendments for
the AMF source category?
    A. Residual Risk Review for the AMF Source Category
    B. Technology Review for the AMF Source Category
    C. Sections 112(d)(2) & (3) Amendments for the AMF Source
Category
V. What is the rationale for our final decisions and amendments for
the APR source category?
    A. Residual Risk Review for the APR Source Category
    B. Technology Review for the APR Source Category
    C. Sections 112(d)(2) & (3) Amendments for the APR Source
Category
VI. What is the rationale for our final decisions and amendments for
the PC source category?
    A. Residual Risk Review for the PC Source Category
    B. Technology Review for the PC Source Category
VII. What is the rationale for our final decisions and amendments
that apply to all three source categories?
    A. Startup, Shutdown and Malfunction
    B. Pressure Relief Devices
    C. Open-Ended Valves and Lines
VIII. Summary of Cost, Environmental and Economic Impacts
    A. What are the affected sources?
    B. What are the air quality impacts?
    C. What are the cost impacts?
    D. What are the economic impacts?
    E. What are the benefits?
    F. What demographic groups might benefit from this regulation?
IX. 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
    C. Regulatory Flexibility Act
    D. Unfunded Mandates Reform Act
    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
    K. Congressional Review Act

I. General Information

A. Does this action apply to me?

    Regulated Entities. Categories and entities potentially regulated
by this action are shown in Table 1 of this preamble.

 Table 1--NESHAP and Industrial Source Categories Affected By This Final
                                 Action
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               NESHAP and Source Category                 NAICS \a\ Code
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Generic Maximum Achievable       Acrylic and Modacrylic           325220
 Control Technology Standards.    Fibers Production.            (325222)
                                 Polycarbonate                    325211
                                  Production.                   (325211)
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Amino/Phenolic Resins            .......................          325211
 Production.                                                    (325211)
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\a\ North American Industry Classification System 2012 (2007 in
  parenthesis)

    Table 1 of this preamble is not intended to be exhaustive, but
rather to provide a guide for readers regarding entities likely to be
affected by the final action for the source categories listed. To
determine whether your facility is affected, you should examine the
applicability criteria in the appropriate NESHAP. If you have any
questions regarding the applicability of any aspect of these NESHAP,
please contact the appropriate person listed in the preceding FOR
FURTHER INFORMATION CONTACT section of this preamble.

B. Where can I get a copy of this document and other related
information?

    In addition to being available in the docket, an electronic copy of
this final action will also be available through the EPA's Technology
Transfer Network (TTN) Web site, a forum for information and technology
exchange in various areas of air pollution control. Following signature
by the EPA Administrator, we will post a copy of the final action at:
http://www.epa.gov/ttn/atw/gmact/gmactpg.html and http://www.epa.gov/ttn/atw/amino/aminopg.html. Following publication in the Federal
Register, the EPA will post the Federal Register version of the final
action and key technical documents at these same Web sites.
    Additional information is available on the RTR Web site at http://www.epa.gov/ttn/atw/rrisk/rtrpg.html. This information includes an
overview of the RTR program, links to project Web sites for the RTR
source categories and detailed emissions and other data we used as
inputs to the risk assessments.

C. Judicial Review

    Under Clean Air Act (CAA) section 307(b)(1), judicial review of
this final action is available only by filing a petition for review in
the United States Court of Appeals for the District of Columbia Circuit
by December 8, 2014. Under CAA section 307(b)(2), the requirements
established by this final rule may not be challenged separately in any
civil or criminal proceedings brought by the EPA to enforce the
requirements.
    Section 307(d)(7)(B) of the CAA further provides that ``[o]nly an
objection to a rule or procedure which was raised with reasonable
specificity during the period for public comment (including any public
hearing) may be raised during judicial review.'' This section also
provides a mechanism for the EPA to reconsider the rule ``[i]f the
person raising an objection can demonstrate to the EPA that it was
impracticable to raise such objection within [the period for public
comment] or if the grounds for such objection arose after the period
for public comment (but within the time specified for judicial review)
and if such objection is of central relevance to the outcome of the
rule.'' Any person seeking to make such a demonstration should submit a
Petition for Reconsideration to the Office of the Administrator, U.S.
EPA, Room 3000, WJC Building, 1200 Pennsylvania Ave. NW., Washington,
DC 20460, with a copy to both the person(s) listed in the preceding FOR
FURTHER INFORMATION CONTACT section, and the Associate General Counsel
for

the Air and Radiation Law Office, Office of General Counsel (Mail Code
2344A), U.S. EPA, 1200 Pennsylvania Ave. NW., Washington, DC 20460.

II. Background

A. What is the statutory authority for this action?

    Section 112 of the CAA establishes a two-stage regulatory process
to address emissions of HAP from stationary sources. In the first
stage, we must identify categories of sources emitting one or more of
the HAP listed in CAA section 112(b) and then promulgate technology-
based NESHAP for those sources. ``Major sources'' are those that emit,
or have the potential to emit, any single HAP at a rate of 10 tons per
year (tpy) or more, or 25 tpy or more of any combination of HAP. For
major sources, these standards are commonly referred to as maximum
achievable control technology (MACT) standards and must reflect the
maximum degree of emission reductions of HAP achievable (after
considering cost, energy requirements, and non-air quality health and
environmental impacts). In developing MACT standards, CAA section
112(d)(2) directs the EPA to consider the application of measures,
processes, methods, systems or techniques that reduce the volume of or
eliminate HAP emissions through process changes, substitution of
materials or other modifications; enclose systems or processes to
eliminate emissions; collect, capture or treat HAP when released from a
process, stack, storage or fugitive emissions point; and/or are design,
equipment, work practice or operational standards.
    For these MACT standards, the statute specifies certain minimum
stringency requirements, which are referred to as MACT floor
requirements and may not be based on cost considerations. See CAA
section 112(d)(3). For new sources, the MACT floor cannot be less
stringent than the emission control achieved in practice by the best-
controlled similar source. The MACT standards for existing sources can
be less stringent than floors for new sources, but they cannot be less
stringent than the average emission limitation achieved by the best-
performing 12 percent of existing sources in the category or
subcategory (or the best-performing five sources for categories or
subcategories with fewer than 30 sources). In developing MACT
standards, we must also consider control options that are more
stringent than the floor, under CAA section 112(d)(2). We may establish
standards more stringent than the floor, based on the consideration of
the cost of achieving the emissions reductions, any non-air quality
health and environmental impacts, and energy requirements.
    In the second stage of the regulatory process, the CAA requires the
EPA to undertake two different analyses, which we refer to as the
technology review and the residual risk review. Under the technology
review, we must review the technology-based standards and revise them
``as necessary (taking into account developments in practices,
processes, and control technologies)'' no less frequently than every 8
years, pursuant to CAA section 112(d)(6). Under the residual risk
review, we must evaluate the risk to public health remaining after
application of the technology-based standards and revise the standards,
if necessary, to provide an ample margin of safety to protect public
health or to prevent, taking into consideration costs, energy, safety
and other relevant factors, an adverse environmental effect. The
residual risk review is required within 8 years after promulgation of
the technology-based standards, pursuant to CAA section 112(f). In
conducting the residual risk review, if the EPA determines that the
current standards provide an ample margin of safety to protect public
health, it is not necessary to revise the MACT standards pursuant to
CAA section 112(f).\1\ For more information on the statutory authority
for this rule, see 79 FR 1676 (January 9, 2014).
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    \1\ The U.S. Court of Appeals has affirmed this approach of
implementing CAA section 112(f)(2)(A): NRDC v. EPA, 529 F.3d 1077,
1083 (D.C. Cir. 2008) (``If EPA determines that the existing
technology-based standards provide an `ample margin of safety,' then
the Agency is free to readopt those standards during the residual
risk rulemaking.'').
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B. Acrylic and Modacrylic Fibers Production (AMF)

1. What is the AMF source category and how do the MACT standards
promulgated on June 29, 1999, regulate its HAP emissions?
    The EPA promulgated the AMF MACT standards on June 29, 1999 (64 FR
34854). The standards are codified at 40 CFR part 63, subpart YY. The
AMF industry consists of facilities that produce acrylic and modacrylic
fibers, which are manufactured fibers in which the fiber-forming
substance is a long-chain synthetic polymer containing acrylonitrile
units. The source category covered by this NESHAP currently includes
one facility. Sources of HAP emissions from the production of AMF
include: (1) Storage vessels used to store acrylonitrile monomer and
co-monomers; (2) process vents on reactors, vessels and storage vessels
used for acrylic polymerization, monomer recovery, fiber spinning and
solvent recovery operations; (3) fugitive emissions from AMF spinning
lines; (4) wastewater treatment systems; and (5) equipment leaks.
2. What changes did we propose for the AMF source category in our
January 9, 2014, proposal?
    On January 9, 2014, the EPA published a proposed rule in the
Federal Register for the AMF MACT standards, 40 CFR part 63, subpart
YY, that took into consideration the RTR analyses. In the proposed
rule, we proposed:
     Revisions to address certain emission sources not
previously regulated under the standards.
     Revisions to the leak detection and repair (LDAR) program
requirements.
     Revisions to requirements related to emissions during
periods of startup, shutdown and malfunction (SSM).
     Revisions to requirements related to performance test
electronic reporting.
     Revisions to the provisions regarding open-ended lines.
     Revisions to the requirements related to pressure relief
devices (PRDs) that release HAP emissions to the atmosphere instead of
routing them to a control device, process, fuel gas system or drain
system.

C. Amino/Phenolic Resins Production (APR)

1. What is the APR source category and how do the MACT standards
promulgated on January 20, 2000, regulate its HAP emissions?
    The EPA promulgated the APR MACT standards on January 20, 2000 (65
FR 3276). The standards are codified at 40 CFR part 63, subpart OOO.
The APR industry consists of facilities that manufacture amino resins
or phenolic resins. The source category covered by this NESHAP
currently includes 19 facilities. Sources of HAP emissions from the
production of APR include: (1) Reactor batch process vents; (2) non-
reactor batch process vents; (3) continuous process vents; (4)
equipment leaks; (5) wastewater; (6) storage vessels; and (7) heat
exchangers.
2. What changes did we propose for the APR source category in our
January 9, 2014, proposal?
    On January 9, 2014, the EPA published a proposed rule in the
Federal Register for the APR MACT standards, 40 CFR part 63, subpart
OOO, that took into consideration the RTR analyses. In the proposed
rule, we proposed:

     Revisions to address certain emission sources not
previously regulated under the standards.
     Revisions to the storage vessel and continuous process
vent standards.
     Revisions to requirements related to emissions during
periods of SSM.
     Revisions to requirements related to performance test
electronic reporting.
     Revisions to the provisions regarding open-ended lines.
     Revisions to the requirements related to PRDs that release
HAP emissions to the atmosphere rather than routing them to a control
device, process, fuel gas system or drain system.

D. Polycarbonate Production

1. What is the PC source category and how do the MACT standards
promulgated on June 29, 1999, regulate its HAP emissions?
    The EPA promulgated the PC MACT standards on June 29, 1999 (64 FR
34854). The standards are codified at 40 CFR part 63, subpart YY. The
PC industry consists of facilities that produce polycarbonates, a
process that involves a polymerization reaction using either a solution
or suspension process in either a batch or continuous mode. All
production of polycarbonates in the United States is currently based on
the polymerization reaction of bisphenols with phosgene in the presence
of catalysts, solvents (mainly methylene chloride) and other additives.
The source category covered by this NESHAP currently includes four
facilities. Sources of HAP emissions from the production of PC include:
(1) Storage vessels used to store methylene chloride and other organic
solvents; (2) process vents on polymerization, polymer solution
purification and solvent recovery equipment; (3) wastewater treatment
systems; and (4) equipment leaks.
2. What changes did we propose for the PC source category in our
January 9, 2014, proposal?
    On January 9, 2014, the EPA published a proposed rule in the
Federal Register for the PC MACT standards, 40 CFR part 63, subpart YY,
that took into consideration the RTR analyses. In the proposed rule, we
proposed:
     Revisions to the LDAR program requirements.
     Revisions to requirements related to emissions during
periods of SSM.
     Revisions to requirements related to performance test
electronic reporting.
     Revisions to the provisions regarding open-ended lines.
     Revisions to the requirements related to PRDs that release
HAP emissions to the atmosphere rather than routing them to a control
device, process, fuel gas system or drain system.

III. What is included in this final rule?

    This action finalizes the EPA's determinations pursuant to the RTR
provisions of CAA section 112 for the AMF, APR and PC source categories
and amends the AMF, APR and PC MACT standards based on those
determinations. This action also finalizes other changes to the NESHAP
such as setting emission standards to address certain emission sources
not previously regulated; eliminating the exemption for periods of SSM,
so that the emission standards in each rule apply at all times;
requiring electronic reporting of performance test results; clarifying
the provisions regarding open-ended lines by adding a definition for
what constitutes a ``sealed'' open-ended line; requiring monitoring of
PRDs in organic HAP service that release to the atmosphere rather than
routing emissions to a control device, process, fuel gas system or
drain system; and providing that releases of HAP emissions to the
atmosphere from such PRDs are prohibited.

A. Acrylic and Modacrylic Fibers Production

1. What are the final rule amendments based on the risk review for the
AMF source category?
    For the AMF source category, we have determined that the current
MACT standards reduce risk to an acceptable level, provide an ample
margin of safety to protect public health, and prevent adverse
environmental effects. Therefore, as we proposed, it is not necessary
to revise the MACT standards pursuant to CAA section 112(f).
2. What are the final rule amendments based on the technology review
for the AMF source category?
    We have determined that there have been developments in practices,
processes and control technologies that warrant revisions to the MACT
standard for this source category. Therefore, to satisfy the
requirements of CAA section 112(d)(6) and as we proposed, we are
revising the MACT standards to require facilities to comply with the
LDAR requirements of 40 CFR part 63, subpart UU, rather than subpart
TT, with the exception of connectors in gas and vapor service and in
light liquid service. We are retaining the option for facilities to
comply with either subpart TT or subpart UU for these components. For
storage vessels, process vents, spinning line fugitive emissions and
wastewater, we have determined that, as we proposed, there are no
viable developments in HAP emission reduction practices, processes or
control technologies to apply, considering the technical feasibility,
estimated costs, energy implications, non-air environmental impacts and
emission reductions of the options identified.
3. What are the final rule amendments pursuant to sections 112(d)(2) &
(3) for the AMF source category?
    Pursuant to CAA sections 112(d)(2) and (3) and as we proposed, we
are establishing standards for previously unregulated HAP emissions
from spinning lines that use a spin dope produced from a solution
polymerization process at existing facilities. The standard being
finalized is an emission limit of 20 kilograms (kg) of organic HAP per
megagram (Mg) (40 pounds (lb) of organic HAP per ton) of acrylic and
modacrylic fiber produced, which represents the MACT floor level of
control.

B. Amino/Phenolic Resins Production

1. What are the final rule amendments based on the risk review for the
APR source category?
    For the APR source category, we have determined that the current
MACT standards reduce risk to an acceptable level, provide an ample
margin of safety to protect public health and prevent adverse
environmental effects. Therefore, as we proposed, it is not necessary
to revise the MACT standards pursuant to CAA section 112(f).
2. What are the final rule amendments based on the technology review
for the APR source category?
    We have determined that there have been developments in practices,
processes and control technologies that warrant revisions to the MACT
standard for this source category. Therefore, to satisfy the
requirements of CAA section 112(d)(6), we are revising the
applicability of the APR new source MACT standards as we proposed to
include smaller capacity storage vessels and/or storage vessels
containing liquids with lower vapor pressures. Emissions reduction of
95 percent is now required for storage vessels of capacities greater
than or equal to 20,000 gallons (gal), but less than 40,000 gal if the
maximum true vapor pressure (MTVP) is 1.9 pounds per square inch
absolute (psia) or greater, and for storage vessels of capacities
greater than or equal to 40,000 gal, but less than 90,000 gal if the
MTVP is 0.75 psia or greater. Control is also still required for
storage

vessels of 90,000 gal or greater, if the MTVP is 0.15 psia or greater,
as was previously required for storage vessels at new sources in the
APR source category. For equipment leaks, continuous process vents,
batch process vents, wastewater and heat exchange systems, we have
determined that, as we proposed, there are no viable developments in
HAP emission reduction practices, processes or control technologies to
apply to the emission sources in these source categories, considering
the technical feasibility, estimated costs, energy implications, non-
air environmental impacts and emission reductions of the options
identified.
3. What are the final rule amendments pursuant to sections 112(d)(2) &
(3) for the APR source category?
    Pursuant to CAA sections 112(d)(2) and (3), we are establishing
standards for previously unregulated HAP emissions from storage vessels
and continuous process vents at existing facilities. For storage
vessels, the standard being finalized is the same as what we proposed
and requires 95 percent emissions reduction for storage vessels of
capacities greater than or equal to 20,000 gal, but less than 40,000
gal if the MTVP is 1.9 psia or greater, for storage vessels of
capacities greater than or equal to 40,000 gal, but less than 90,000
gal if the MTVP is 0.75 psia or greater, and for storage vessels of
90,000 gal or greater, if the MTVP is 0.15 psia or greater, which
represents a beyond-the-floor level of control. For continuous process
vents, the standard being finalized establishes an emission limit of
0.95 kg of organic HAP per Mg (1.9 lb organic HAP per ton) of resin
produced, which represents the MACT floor level of control. However,
the calculation of the MACT floor has been revised since proposal.

C. Polycarbonate Production

1. What are the final rule amendments based on the risk review for the
PC source category?
    For the PC source category, we have determined that the current
MACT standards reduce risk to an acceptable level, provide an ample
margin of safety to protect public health and prevent adverse
environmental effects. Therefore, as we proposed, it is not necessary
to revise the MACT standards pursuant to CAA section 112(f).
2. What are the final rule amendments based on the technology review
for the PC source category?
    We have determined that there have been developments in practices,
processes and control technologies that warrant revisions to the MACT
standard for this source category. Therefore, to satisfy the
requirements of CAA section 112(d)(6) and as we proposed, we are
revising the MACT standards to require facilities to comply with the
LDAR requirements of 40 CFR part 63, subpart UU, rather than subpart
TT, with the exception of connectors in gas and vapor service and in
light liquid service. We are retaining the option for facilities to
comply with either subpart TT or subpart UU for these components. For
storage vessels, process vents and wastewater treatment systems, we
have determined that, as we proposed, there are no viable developments
in HAP emission reduction practices, processes or control technologies
to apply to the emission sources in these source categories,
considering the technical feasibility, estimated costs, energy
implications, non-air environmental impacts and emission reductions of
the options identified.

D. What are the final rule amendments for all three source categories
addressing emissions during periods of startup, shutdown and
malfunction?

    In its 2008 decision in Sierra Club v. EPA, 551 F.3d 1019 (D.C.
Cir. 2008), cert. denied, 130 S. Ct. 1735 (U.S. 2010), the United
States Court of Appeals for the District of Columbia Circuit vacated
portions of two provisions in the EPA's CAA section 112 regulations
governing the emissions of HAP during periods of SSM. Specifically, the
court vacated the SSM exemption contained in 40 CFR 63.6(f)(1) and 40
CFR 63.6(h)(1) holding that under section 302(k) of the CAA, emission
standards or limitations must be continuous in nature and that the SSM
exemption violates the CAA's requirement that some section 112
standards apply continuously.
    We have eliminated the SSM exemption in these rules. Consistent
with Sierra Club v. EPA, the standards in these rules apply at all
times. We are also finalizing several revisions to 40 CFR part 63,
subpart YY and Table 1 to subpart OOO (the General Provisions
applicability table), as is explained in more detail below. For
example, we have eliminated the incorporation of the General
Provisions' requirement that sources develop an SSM plan. We have also
eliminated and revised certain NESHAP recordkeeping and reporting that
is related to the eliminated SSM exemption, as described in detail in
the proposed rule and summarized again here.
    In establishing the standards in these final rule amendments, the
EPA has taken into account startup and shutdown periods and, for the
reasons explained below, has not established alternate standards for
these periods for the AMF, APR and PC MACT standards. Emission
reductions for process vents and transfer operations are typically
achieved by routing vapors to a control device such as a thermal
oxidizer or carbon adsorber. It is common practice to start a control
device prior to startup of the emissions source it is controlling, so
the control device would be operating before emissions are routed to
it. We expect control devices would be operating during startup and
shutdown events in a manner consistent with normal operating periods,
and that these control devices will be operated to maintain and meet
the monitoring parameter operating limits set during the performance
test. We do not expect startup and shutdown events to affect emissions
from equipment leaks, wastewater sources (e.g., surface impoundments,
oil-water separators, organic-water separators) or storage tanks. Leak
detection programs associated with equipment leaks are in place to
detect leaks, and, therefore, it is inconsequential whether the process
is operating under normal operating conditions or is in startup or
shutdown. Wastewater emissions are also not expected to be
significantly affected by startup or shutdown events. Working and
breathing losses from storage tanks are the same regardless of whether
the process is operating under normal operating conditions or is in a
startup or shutdown event.
    Periods of startup, normal operations and shutdown are all
predictable and routine aspects of a source's operations. However, by
contrast, malfunctions are a sudden, infrequent, and not reasonably
preventable failure of air pollution control and monitoring equipment,
process equipment, or a process to operate in a normal or usual manner.
See 40 CFR 63.2. The EPA interprets CAA section 112 as not requiring
emissions that occur during periods of malfunction to be factored into
development of CAA section 112 standards. Under section 112, emission
standards for new sources must be no less stringent than the level
``achieved'' by the best controlled similar source and, for existing
sources, generally must be no less stringent than the average emission
limitation ``achieved'' by the best performing 12 percent of sources in
the category. There is nothing in section

112 that directs the EPA to consider malfunctions in determining the
level ``achieved'' by the best performing sources when setting emission
standards. As the United States Court of Appeals for the District of
Columbia Circuit has recognized, the phrase ``average emissions
limitation achieved by the best performing 12 percent of '' sources
``says nothing about how the performance of the best units is to be
calculated.'' Nat'l Ass'n of Clean Water Agencies v. EPA, 734 F.3d
1115, 1141 (D.C. Cir. 2013). While the EPA accounts for variability in
setting emission standards, nothing in CAA section 112 requires the EPA
to consider malfunctions as part of that analysis. A malfunction should
not be treated in the same manner as the type of variation in
performance that occurs during routine operations of a source. A
malfunction is a failure of the source to perform in a ``normal or
usual manner'' and no statutory language compels the EPA to consider
such events in setting CAA section 112 standards.
    Further, accounting for malfunctions in setting emission standards
would be difficult, if not impossible, given the myriad different types
of malfunctions that can occur across all sources in the source
categories amended with this action, and given the difficulties
associated with predicting or accounting for the frequency, degree and
duration of various malfunctions that might occur. As such, the
performance of units that are malfunctioning is not ``reasonably''
foreseeable. See, e.g., Sierra Club v. EPA, 167 F.3d 658, 662 (D.C.
Cir. 1999) (``The EPA typically has wide latitude in determining the
extent of data-gathering necessary to solve a problem. We generally
defer to an agency's decision to proceed on the basis of imperfect
scientific information, rather than to `invest the resources to conduct
the perfect study.' ''). See also, Weyerhaeuser v. Costle, 590 F.2d
1011, 1058 (D.C. Cir. 1978) (``In the nature of things, no general
limit, individual permit, or even any upset provision can anticipate
all upset situations. After a certain point, the transgression of
regulatory limits caused by `uncontrollable acts of third parties,'
such as strikes, sabotage, operator intoxication or insanity, and a
variety of other eventualities, must be a matter for the administrative
exercise of case-by-case enforcement discretion, not for specification
in advance by regulation.''). In addition, emissions during a
malfunction event can be significantly higher than emissions at any
other time of source operation. For example, if an air pollution
control device with 99 percent removal goes off-line as a result of a
malfunction (as might happen if, for example, the bags in a baghouse
catch fire) and the emission unit is a steady state type unit that
would take days to shut down, the source would go from 99 percent
control to zero control until the control device was repaired. The
source's emissions during the malfunction would be 100 times higher
than during normal operations. As such, the emissions over a 4-day
malfunction period would exceed the annual emissions of the source
during normal operations. As this example illustrates, accounting for
malfunctions could lead to standards that are not reflective of (and
significantly less stringent than) levels that are achieved by a well-
performing non-malfunctioning source. It is reasonable to interpret
section 112 to avoid such a result. The EPA's approach to malfunctions
is consistent with CAA section 112 and is a reasonable interpretation
of the statute.
    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).
    If the EPA determines in a particular case that enforcement action
against a source for violation of an emission standard is warranted,
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.
Similarly, the presiding officer in an administrative proceeding can
consider any defense raised and determine whether administrative
penalties are appropriate.
    In summary, the EPA interpretation of the CAA and in particular,
section 112 is reasonable and encourages practices that will avoid
malfunctions. Administrative and judicial procedures for addressing
exceedances of the standards fully recognize that violations may occur
despite good faith efforts to comply and can accommodate those
situations.
    In several prior CAA section 112 rules and in the proposed 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,
No. 10-1371 (D.C. Cir. April 18, 2014) 2014 U.S. App. LEXIS 7281
(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' in a given private civil suit is a job for
the courts, not EPA.'').\2\ In

light of NRDC, the EPA is not including a regulatory affirmative
defense provision in the final rule. As explained above, if a source is
unable to comply with emission standards as a result of a malfunction,
the EPA may use its case-by-case enforcement discretion to provide
flexibility, as appropriate. Further, as the United States Court of
Appeals for the District of Columbia Circuit recognized, in an EPA or
citizen enforcement action, the court has the discretion to consider
any defense raised and determine whether penalties are appropriate. Cf.
NRDC, 2014 U.S. App. LEXIS 7281 at *24. (Arguments that violations were
caused by unavoidable technology failure can be made to the courts in
future civil cases when the issue arises). The same is true for the
presiding officer in EPA administrative enforcement actions.\3\
---------------------------------------------------------------------------

    \2\ The court's reasoning in NRDC focuses on civil judicial
actions. The court noted that ``EPA's ability to determine whether
penalties should be assessed for Clean Air Act violations extends
only to administrative penalties, not to civil penalties imposed by
a court.'' Id.
    \3\ Although the NRDC case does not address the EPA's authority
to establish an affirmative defense to penalties that is available
in administrative enforcement actions, the EPA is not including such
an affirmative defense in the final rule. As explained above, such
an affirmative defense is not necessary. Moreover, assessment of
penalties for violations caused by malfunctions in administrative
proceedings and judicial proceedings should be consistent. CF. CAA
section 113(e) (requiring both the Administrator and the court to
take specified criteria into account when assessing penalties).
---------------------------------------------------------------------------

    Refer to the explanations below and section VII of this preamble
and the comment summary and response document, available in the docket
for this action, for further discussion regarding SSM-related changes
made to the AMF, APR and PC MACT standards.
1. General Duty
    For the APR MACT standards, we are revising the General Provisions
applicability table (Table 1 to Subpart OOO) entry for 40 CFR
63.6(e)(1)(i) by changing the explanation in column 3. 40 CFR
63.6(e)(1)(i) describes the general duty to minimize emissions. Some of
the language in that section is no longer necessary or appropriate in
light of the elimination of the SSM exemption. Similarly, for the AMF
and PC source categories, we are also removing this requirement at 40
CFR 63.1108(a)(5). For the AMF, APR and PC MACT standards, we are
instead adding general duty regulatory text at 40 CFR 63.1108(a)(4)(ii)
and 63.1400(k)(4) that reflects the general duty to minimize emissions
while eliminating the reference to periods covered by an SSM exemption.
The current language in 40 CFR 63.6(e)(1)(i) characterizes what the
general duty entails during periods of SSM. With the elimination of the
SSM exemption, there is no need to differentiate between normal
operations, startup and shutdown and malfunction events in describing
the general duty. Therefore, the language the EPA is promulgating for
40 CFR 63.1108(a)(4)(ii) and 63.1400(k)(4) does not include that
language from 40 CFR 63.6(e)(1).
    For the APR MACT standards, we are also revising the General
Provisions applicability table (Table 1 to Subpart OOO) entry for 40
CFR 63.6(e)(1)(ii) by changing the ``yes'' in the second column to a
``no.'' 40 CFR 63.6(e)(1)(ii) imposes requirements that are not
necessary with the elimination of the SSM exemption or are redundant
with the general duty requirement being added at 40 CFR 63.1400(k)(4).
2. SSM Plan
    For the APR MACT standards, we are revising the General Provisions
applicability table (Table 1 to Subpart OOO) entry for 40 CFR
63.6(e)(3) by changing the ``yes'' in the second column to a ``no.''
Similarly, for the AMF and PC source categories, we are also removing
this requirement at 40 CFR 63.1111(a). Generally, these paragraphs
require development of an SSM plan and specify SSM recordkeeping and
reporting requirements related to the SSM plan. As noted, the EPA is
removing the SSM exemptions. Therefore, affected units will be subject
to an emission standard during such events. The applicability of a
standard during such events will ensure that sources have ample
incentive to plan for and achieve compliance and thus the SSM plan
requirements are no longer necessary.
3. Compliance With Standards
    For the APR MACT standards, we are revising the General Provisions
applicability table (Table 1 to Subpart OOO) entry for 40 CFR
63.6(f)(1) by changing the ``yes'' in the second column to a ``no.''
The current language of 40 CFR 63.6(f)(1) exempts sources from non-
opacity standards during periods of SSM. As discussed above, the court
in Sierra Club vacated the exemptions contained in this provision and
held that the CAA requires that some section 112 standard apply
continuously. Consistent with Sierra Club, the EPA is revising
standards in this rule to apply at all times.
4. Performance Testing
    For the APR MACT standards, we are revising the General Provisions
applicability table (Table 1 to Subpart OOO) entry for 40 CFR
63.7(e)(1) by changing the ``yes'' in the second column to a ``no.'' 40
CFR 63.7(e)(1) describes performance testing requirements. Similarly,
for the AMF and PC source categories, we are also revising this
requirement at 40 CFR 63.1108(b)(4)(ii). The EPA is instead adding a
performance testing requirement at 40 CFR 63.1108(b)(4)(ii) and
63.1413(a)(2). The performance testing requirements we are adding
differ from the General Provisions performance testing provisions in
several respects. The regulatory text does not include the language in
40 CFR 63.7(e)(1) that restated the SSM exemption and language that
precluded startup and shutdown periods from being considered
``representative'' for purposes of performance testing. The revised
performance testing provisions do not allow performance testing during
periods of startup or shutdown. As in 40 CFR 63.7(e)(1), performance
tests conducted under this subpart should not be conducted during
malfunctions because conditions during malfunctions are not
representative of normal operating conditions. The EPA is adding
language that requires the owner or operator to record the process
information that is necessary to document operating conditions during
the test and include in such record an explanation to support that such
conditions represent normal operation. 40 CFR 63.7(e) requires that the
owner or operator make available to the Administrator such records ``as
may be necessary to determine the condition of the performance test''
available to the Administrator upon request, but does not specifically
require the information to be recorded. The regulatory text the EPA is
adding to this provision builds on that requirement and makes explicit
the requirement to record the information.
5. Monitoring
    For the APR MACT standards, we are revising the General Provisions
applicability table (Table 1 to Subpart OOO) entries for 40 CFR
63.8(c)(1)(i) and (iii) by changing the ``yes'' in the second column to
a ``no.'' The cross-references to the general duty and SSM plan
requirements in those subparagraphs are not necessary in light of other
requirements of 40 CFR 63.8 that require good air pollution control
practices (40 CFR 63.8(c)(1)) and that set out the requirements of a
quality control program for monitoring equipment (40 CFR 63.8(d)).
6. Recordkeeping
    For the AMF, APR and PC MACT standards, the EPA is adding
recordkeeping requirements during a malfunction to 40 CFR 63.1111(c)(1)
and

63.1416(b). The EPA is applying the requirement to any failure to meet
an applicable standard and is requiring that the source record the
date, time, and duration of the failure rather than the ``occurrence.''
The EPA is also adding to 40 CFR 63.1111(c)(1) and 63.1416(b) a
requirement that sources keep records that include a list of the
affected source or equipment and actions taken to minimize emissions,
an estimate of the quantity of each regulated pollutant emitted over
the standard for which the source failed to meet the standard and a
description of the method used to estimate the emissions. Examples of
such methods would include product-loss calculations, mass balance
calculations, measurements when available or engineering judgment based
on known process parameters. The EPA is requiring that sources keep
records of this information to ensure that there is adequate
information to allow the EPA to determine the severity of any failure
to meet a standard, and to provide data that may document how the
source met the general duty to minimize emissions when the source has
failed to meet an applicable standard.
7. Reporting
    For the APR MACT standards, we are revising the General Provisions
applicability table (Table 1 to Subpart OOO) entry for 40 CFR
63.10(d)(5) by changing the ``yes'' in the second column to a ``no.''
40 CFR 63.10(d)(5) describes the reporting requirements for SSM.
Similarly, for the AMF and PC source categories, we are also removing
this requirement at 40 CFR 63.1111(b). To replace the General
Provisions reporting requirement, the EPA is adding reporting
requirements to 40 CFR 63.1111(c)(2) and 63.1417(g). The replacement
language differs from the General Provisions requirement in that it
eliminates periodic SSM reports as a stand-alone report. We are
promulgating language that requires sources that fail to meet an
applicable standard at any time to report the information concerning
such events in the semi-annual periodic report already required under
these rules. We are promulgating that the report must contain the
number, date, time, duration and cause of such events (including
unknown cause, if applicable), a list of the affected source or
equipment, an estimate of the quantity of each regulated pollutant
emitted over any emission limit and a description of the method used to
estimate the emissions.
    Examples of such methods would include product-loss calculations,
mass balance calculations, measurements when available or engineering
judgment based on known process parameters. The EPA is promulgating
this requirement to ensure that there is adequate information to
determine compliance, to allow the EPA to determine the severity of the
failure to meet an applicable standard, and to provide data that may
document how the source met the general duty to minimize emissions
during a failure to meet an applicable standard.
    We will no longer require owners or operators to determine whether
actions taken to correct a malfunction are consistent with an SSM plan,
because plans will no longer be required. The final amendments
therefore eliminate the cross reference to 40 CFR 63.10(d)(5)(i) that
contains the description of the previously required SSM report format
and submittal schedule from this section. These specifications are no
longer necessary because the events will be reported in otherwise
required reports with similar format and submittal requirements.
    For the APR MACT standards, we are revising the General Provisions
applicability table (Table 1 to Subpart OOO) entry for 40 CFR
63.10(d)(5)(ii) by changing the ``yes'' in the second column to a
``no.'' 40 CFR 63.10(d)(5)(ii) describes an immediate report for
startups, shutdown and malfunctions when a source failed to meet an
applicable standard but did not follow the SSM plan. We will no longer
require owners or operators to report when actions taken during a
startup, shutdown or malfunction were not consistent with an SSM plan,
because plans will no longer be required.

E. What other changes have been made to all three NESHAP?

1. Pressure Relief Devices
    PRDs are designed to remain closed during normal operation and only
release as the result of unplanned and/or unpredictable events. A
release from a PRD usually occurs during an over pressurization of the
system. In some source configurations, emissions from PRDs are captured
and routed to a control device, process, fuel gas system or drain
system, and, therefore, do not result in a net increase of HAP
emissions from the source than would otherwise be the case if the
source met all other applicable HAP emission limits. However, emissions
vented to the atmosphere by PRDs in organic HAP service contain HAP
that are otherwise regulated under the MACT standards that apply to
these source categories, and if such releases to the atmosphere occur
there will be a net increase in source HAP emissions even if the source
otherwise complies with all other applicable HAP limits.
    The original MACT standards for these source categories regulated
PRDs through equipment leak provisions that applied only after the
pressure release occurred. In addition, the rules followed the EPA's
former practice of exempting SSM events from otherwise applicable
emission standards. Consequently, the original MACT standards did not
restrict emissions of organic HAP from PRDs to the atmosphere as a
result of malfunction but instead treated them the same as all
malfunctions through the SSM exemption provision.
    In Sierra Club v. EPA, 551 F.3d 1019 (D.C. Cir. 2008), the court
determined that the SSM exemption violated the CAA. See section III.D
of this preamble for additional discussion. To ensure these NESHAP are
consistent with that decision, the final rule revisions remove the
malfunction exemptions in each of the MACT standards and provide that
emissions of organic HAP may not be discharged to the atmosphere from
PRDs in organic HAP service. The prohibition does not apply to PRD
releases of HAP that are captured and routed to a control device,
process, fuel gas system or drain system.
    To ensure compliance with this amendment, we are also requiring
that sources subject to these three MACT standards monitor PRDs in
organic HAP service that release to the atmosphere by using a device or
system that is capable of identifying and recording the time and
duration of each pressure release and of notifying operators
immediately that a pressure release is occurring. Owners or operators
are required to keep records and report any pressure release and the
amount of organic HAP released to the atmosphere with the next periodic
report. As with the prohibition, this monitoring requirement does not
apply to PRDs for which HAP releases are captured and routed to a
control device, process, fuel gas system or drain system.
    Pressure release events from PRDs in organic HAP service to the
atmosphere have the potential to emit large quantities of uncontrolled
and unmeasured HAP. Where a pressure release occurs, it is important to
identify and mitigate it as quickly as possible. As defined in the MACT
standards, PRDs are valves used only to release unplanned, nonroutine
discharges. A PRD discharge results from an operator error, a
malfunction such as a power failure or equipment failure, or other
unexpected cause that requires immediate venting of gas from process
equipment in order to avoid safety hazards or equipment damage. Even
so,

to the extent that there are atmospheric HAP emissions from PRDs, we
are required to follow the Sierra Club ruling to address those
emissions in these rules, and we can no longer exempt them as
permitted, uncontrolled and unmeasured malfunction emissions as we did
under the previous MACT standards. This concern is not present in the
case of PRDs for which HAP releases are captured and routed to a
control device, process, fuel gas system or drain system, since in
these situations there is no additional uncontrolled and unmeasured HAP
emission occurring beyond that which is already subject to control or
monitoring of the process unit. We recognize that HAP releases to the
atmosphere from PRDs sometimes occur in order to protect systems from
failures that could endanger worker safety and the systems that the
PRDs are designed to protect. 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 63.1101 and 63.1402 (definition of malfunction).
    If the EPA determines in a particular case that enforcement action
against a source for violation of an emission standard is warranted,
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.
Similarly, the presiding officer in an administrative proceeding can
consider any defense raised and determine whether administrative
penalties are appropriate.
    In summary, the EPA interpretation of the CAA and in particular,
section 112 is reasonable and encourages practices that will avoid
malfunctions. Administrative and judicial procedures for addressing
exceedances of the standards fully recognize that violations may occur
despite good faith efforts to comply and can accommodate those
situations.
    Some sources are configured such that PRDs can be effectively used
to address safety issues without consequently adding HAP emissions to
the atmosphere beyond those that are otherwise allowed under applicable
limits. We also recognize, however, that it is not always technically
possible to route emissions from all PRDs to a control device, process,
fuel gas system or drain system. With respect to these PRDs that vent
to the atmosphere, instead, we have provided a balanced approach
designed to minimize emissions while recognizing that these events may
be unavoidable even in a well-designed and maintained (if, albeit,
uncontrolled with respect to PRDs) system.
    For purposes of estimating the costs of the new requirement to
monitor HAP releases to the atmosphere from PRDs, we assumed that
operators would install electronic indicators on each PRD in organic
HAP service that vents to the atmosphere (rather than to a control
device, process, fuel gas system or drain system) to identify and
record the time and duration of each pressure release. However, we are
allowing owners or operators to use a range of methods to satisfy these
requirements, including the use of a parameter monitoring system (that
may already be in place) on the process system or piping that is
sufficient to notify operators immediately that a release is occurring,
as well as recording the time and duration of the pressure release.
Based on our cost assumptions that the most expensive approach would be
used, the nationwide capital cost of installing these monitors is
$37,000, $400,000 and $51,000 for the AMF, APR and PC source
categories, respectively. The total annualized cost of installing and
operating these monitors is $5,300, $60,000 and $7,200 per year for the
AMF, APR and PC source categories, respectively.
2. Open-Ended Valves and Lines
    The AMF MACT standards at 40 CFR 63.1103(b)(3) and the PC MACT
standards at 40 CFR 63.1103(d)(3) require an owner or operator to
control emissions from equipment leaks according to the requirements of
40 CFR part 63, subpart UU. The APR MACT standards at 40 CFR 63.1410
also require that equipment leaks be controlled according to subpart
UU. For open-ended valves and lines, subpart UU requires that the open
end be equipped with a cap, blind flange, plug or second valve that
``shall seal the open end at all times.'' However, neither subpart UU,
nor the AMF, APR or PC MACT standards, define ``seal'' or explain in
practical and enforceable terms what constitutes a sealed open-ended
valve or line. This has led to uncertainty on the part of the owner or
operator as to whether compliance is being achieved. Inspections under
the EPA's Air Toxics LDAR initiative have provided evidence that while
certain open-ended lines may be equipped with a cap, blind flange, plug
or second valve, they are not operating in a ``sealed'' manner as the
EPA interprets that term.
    In response to this uncertainty, we are amending 40 CFR
63.1103(b)(2) (for the AMF MACT standards), 40 CFR 63.1402(b) (for the
APR MACT standards) and 40 CFR 63.1103(d)(2) (for the PC MACT
standards) to clarify what is meant by ``seal.'' This amendment
clarifies that, for the purpose of complying with the requirements of
40 CFR 63.1033(b) of subpart UU, open-ended valves and lines are
``sealed'' by the cap, blind flange, plug or second valve when there
are no detectable emissions from the open-ended valve or line at or
above an instrument reading of 500 ppm.
3. Submission of Performance Test Data to the EPA
    As stated in the preamble to the proposed rule, the EPA is taking a
step to increase the ease and efficiency of data submittal and data
accessibility. Specifically, the EPA is requiring owners and operators
of AMF, APR and PC facilities to submit electronic copies of certain
required performance test reports.
    Data will be collected by direct computer-to-computer electronic
transfer using EPA-provided software. This EPA-provided software is an
electronic performance test report tool called the Electronic Reporting
Tool (ERT). The ERT will generate an electronic report package which
will be submitted to the Compliance and Emissions Data Reporting
Interface (CEDRI) and then archived to the EPA's Central Data Exchange
(CDX). A description and instructions for use of the ERT can be found
at: http://www.epa.gov/ttn/chief/ert/index.html and CEDRI can be
accessed through the CDX Web site: (http://www.epa.gov/cdx).
    The requirement to submit performance test data electronically to
the EPA does not create any additional performance testing and will
apply only to those performance tests conducted using test methods that
are supported by the ERT. A listing of the pollutants and test methods
supported by the ERT is available at the ERT Web site. The EPA
believes, through this approach, industry will save time in the
performance test submittal process.

Additionally, this rulemaking benefits industry by reducing
recordkeeping costs as the performance test reports that are submitted
to the EPA using CEDRI are no longer required to be kept in hard copy.
    State, local and tribal agencies may benefit from more streamlined
and accurate review of performance test data that will become available
to the public through WebFIRE. Additionally, performance test data will
become available to the public through WebFIRE. Having such data
publicly available enhances transparency and accountability. For a more
thorough discussion of electronic reporting of performance tests using
direct computer-to-computer electronic transfer and using EPA-provided
software, see the discussion in the preamble of the proposal.
    In summary, in addition to supporting regulation development,
control strategy development and other air pollution control
activities, having an electronic database populated with performance
test data will save industry, state, local, tribal agencies and the EPA
significant time, money and effort while improving the quality of
emission inventories and, air quality regulations.

F. What are the effective and compliance dates of the standards for all
three source categories?

    The revisions to the MACT standards being promulgated in this
action are effective on October 8, 2014.
    The compliance date for existing AMF, APR and PC sources to comply
with the revised SSM requirements (other than PRD monitoring) is the
effective date of the standard, October 8, 2014. We are finalizing
these compliance dates because these requirements should be immediately
implementable by the facilities upon the next occurrence of a
malfunction or a performance test that is required to be submitted to
the ERT. Available information suggests that the facilities should
already be able to comply with the existing standards during periods of
startup and shutdown.
    The compliance date for AMF, APR and PC sources that commenced
construction or reconstruction on or before January 9, 2014, to comply
with the PRD monitoring requirements is 3 years from the effective date
of the promulgated standards, October 9, 2017. This time is needed
regardless of whether an owner or operator of a facility chooses to
comply with the PRD monitoring provisions by installing PRD release
indicator systems and alarms, employing parameter monitoring or by
routing releases to a control device, process, fuel gas system or drain
system. This time period will allow facilities to research equipment
and vendors, purchase, install, test and properly operate any necessary
equipment by the compliance date.
    The compliance date for existing AMF, APR and PC sources to comply
with the operating and pressure release management requirements for
PRDs, along with the other SSM-related revisions, is the effective date
of the promulgated standards, October 8, 2014. We are finalizing these
compliance dates because these requirements are the same as those
contained in 40 CFR part 63, subpart UU, with which facilities are
already complying as part of the existing MACT standards.
    The compliance date for the one existing AMF source to comply with
the new solution polymerization spinning line requirements is the
effective date of the promulgated standards, October 8, 2014. This
facility is already complying with these requirements and no additional
time to come into compliance is warranted.
    The compliance date for existing APR sources to comply with the new
MACT standards applicable to continuous process vents and storage
vessels is 3 years from the effective date of the promulgated
standards, October 9, 2017. This time period will allow facilities to
purchase, install and test any necessary equipment.
    The compliance date for existing AMF and PC sources to comply with
the revised equipment leak standards is 1 year from the effective date
of the promulgated standards, October 8, 2015. Our data indicate that
the one AMF facility and some of the PC facilities are currently
complying with 40 CFR part 63, subpart TT requirements and will need
time to purchase, install and test any necessary equipment and modify
their existing LDAR programs.
    New sources that commenced or commence construction or
reconstruction after January 9, 2014, must comply with the all of the
revised standards immediately upon the effective date of the standard,
October 8, 2014, or upon startup, whichever is later.

IV. What is the rationale for our final decisions and amendments for
the AMF source category?

    For each issue, this section provides a description of what we
proposed and finalized for the issue, the EPA's rationale for the final
decisions and amendments and a summary of key comments and responses.
For all comments not discussed in this preamble, comment summaries and
the EPA's responses can be found in the comment summary and response
document available in the docket.

A. Residual Risk Review for the AMF Source Category

1. What did we propose pursuant to CAA section 112(f) for the AMF
source category?
    For the AMF source category, the results of the inhalation risk
assessment indicated the maximum lifetime individual cancer risk could
be up to 20-in-1 million, the estimated maximum chronic non-cancer
target organ-specific hazard index (TOSHI) value was 0.1 and the
estimated maximum off-facility site acute HQ value was 0.08, based on
the actual emissions level and the AEGL-1 value for acrylonitrile. The
total estimated national cancer incidence from the one AMF facility
based on actual emission levels was 0.006 excess cancer cases per year
or one case in every 170 years. The EPA proposed that no amendments
were needed for this source category based on the risk review under CAA
section 112(f). See 79 FR 1697-1700 (January 9, 2014).
2. How did the risk review change for the AMF source category?
    For the AMF source category, the risk review has not changed since
proposal.
3. What key comments did we receive on the risk review, and what are
our responses?
    For the AMF source category, the comments received on the proposed
risk review were generally supportive. A summary of these comments and
our responses can be found in the comment summary and response document
available in the docket for this action (EPA-HQ-OAR-2012-0133).
4. What is the rationale for our final approach for the risk review?
    The results of the risk assessment for the AMF source category did
not change from proposal and, therefore, they did not affect our
determinations regarding risk acceptability and ample margin of safety.
The full results of the risk assessment for the AMF source category can
be found in the risk assessment documentation available in the docket
for this action (EPA-HQ-OAR-2012-0133).
    Uncertainty and the potential for bias are inherent in all risk
assessments, including those performed for the source categories
addressed in this final rule. Although uncertainty exists, we believe
that our approach, which used conservative tools and assumptions,
ensures that our decisions are health-protective. A discussion of the

uncertainties in the emissions datasets, dispersion modeling,
inhalation exposure estimates and dose-response relationships is
provided in the preamble to the proposed rule. See 79 FR 1684 (January
9, 2014).
    In accordance with the approach established in the Benzene NESHAP,
the EPA weighed all health risk measures and information considered in
the risk acceptability determination, along with additional factors
relating to the appropriate level of control, including the costs and
economic impacts of emissions controls, technological feasibility,
uncertainties and other relevant factors in making our risk
acceptability and ample margin of safety determination. Considering all
of these factors, the EPA has determined that the risks from the AMF
source category are acceptable and that the current MACT standards in
40 CFR part 63, subpart YY for the AMF source category provide an ample
margin of safety to protect public health.

B. Technology Review for the AMF Source Category

1. What did we propose pursuant to CAA section 112(d)(6) for the AMF
source category?
    For the AMF source category, the EPA proposed to eliminate the less
stringent of two currently available options for complying with LDAR
program requirements, while retaining the more stringent compliance
requirement. The AMF MACT standards previously required compliance with
either subpart TT or subpart UU of 40 CFR part 63 to control emissions
from equipment leaks. As part of the technology review for the AMF
source category, we proposed to require facilities to comply with
subpart UU rather than subpart TT, with the exception of connectors in
gas and vapor service and in light liquid service. We proposed to
retain the option to comply with either subpart TT or subpart UU for
those components. See 79 FR 1700-1701.
2. How did the technology review change for the AMF source category?
    For the AMF source category, the technology review has not changed
since proposal.
3. What key comments did we receive on the technology review, and what
are our responses?
    For the AMF source category, the comments received on the proposed
technology review were generally supportive. A summary of these
comments and our responses can be found in the comment summary and
response document available in the docket for this action (EPA-HQ-OAR-
2012-0133).
4. What is the rationale for our final approach for the technology
review?
    The results of the technology review for the AMF source category
did not change from proposal. Therefore the EPA is requiring AMF
facilities to comply with 40 CFR part 63, subpart UU rather than 40 CFR
part 63, subpart TT, with the exception of connectors in gas and vapor
service and in light liquid service. Facilities continue to have the
option to comply with either subpart TT or subpart UU for those
components.

C. Sections 112(d)(2) & (3) Amendments for the AMF Source Category

1. What did we propose pursuant to sections 112(d)(2) & (3) for the AMF
source category?
    For the AMF source category, the EPA identified the absence of an
emissions limit for spinning lines that use a spin dope produced from a
solution polymerization process at existing AMF facilities. Pursuant to
CAA sections 112(d)(2) and (3), we proposed to establish an emissions
limit of 20 kg organic HAP-Mg (40 lb organic HAP-ton) of acrylic and
modacrylic fiber produced for this emission point, which represented
the MACT floor emissions limit. See 79 FR 1697.
2. How do the final amendments pursuant to sections 112(d)(2) & (3)
differ from the proposal for the AMF source category?
    For the AMF source category, the emissions limit for spinning lines
that use a spin dope produced from a solution polymerization process at
existing AMF facilities has not changed since proposal.
3. What key comments did we receive on the amendments proposed pursuant
to sections 112(d)(2) & (3) for the AMF source category, and what are
our responses?
    For the AMF source category, the comments received on the proposed
emissions limit for spinning lines that use a spin dope produced from a
solution polymerization process at existing AMF facilities were
generally supportive. A summary of these comments and our responses can
be found in the comment summary and response document available in the
docket for this action (EPA-HQ-OAR-2012-0133).
4. What is the rationale for our final approach for the final
amendments pursuant to sections 112(d)(2) & (3) for the AMF source
category?
    The analysis of the emissions limit for spinning lines that use a
spin dope produced from a solution polymerization process at existing
AMF facilities did not change from proposal. Therefore, the EPA is
establishing an emissions limit at the MACT floor for this emission
point: 20 kg organic HAP-Mg (40 lb organic HAP-ton) of acrylic and
modacrylic fiber produced.

V. What is the rationale for our final decisions and amendments for the
APR source category?

    For each issue, this section provides a description of what we
proposed and finalized for the issue, the EPA's rationale for the final
decisions and amendments and a summary of key comments and responses.
For all comments not discussed in this preamble, comment summaries and
the EPA's responses can be found in the comment summary and response
document available in the docket.

A. Residual Risk Review for the APR Source Category

1. What did we propose pursuant to CAA section 112(f) for the APR
source category?
    For the APR source category, the results of the inhalation risk
assessment indicated the maximum lifetime individual cancer risk could
be up to 9-in-1 million, the estimated maximum chronic non-cancer TOSHI
value was 0.2 and the estimated maximum off-facility site acute hazard
quotient (HQ) value was 10, based on the actual emissions level and the
reference exposure level (REL) value for formaldehyde. The total
estimated national cancer incidence from APR facilities based on actual
emission levels was 0.001 excess cancer cases per year or one case in
every 1,000 years. The EPA proposed that no amendments were needed for
this source category based on the risk review under CAA section 112(f).
See 79 FR 1703-1706.
2. How did the risk review change for the APR source category?
    For the APR source category, we received information indicating
that an additional facility should have been included in the risk
assessment for this source category. Using information submitted by
this facility, we revised the risk assessment for this source category.
The MIR increased from 9- to 20-in-1 million, the annual cancer
incidence increased from 0.001 to 0.002

cases per year, the maximum chronic non-cancer TOSHI value increased
from 0.2 to 0.4, and the maximum off-site acute HQ value stayed the
same at 10, based on the REL value for formaldehyde. Table 2 provides
an overall summary of the revised inhalation risk assessment results
for the APR source category.

                                                     Table 2--APR Inhalation Risk Assessment Results
--------------------------------------------------------------------------------------------------------------------------------------------------------
                  Maximum individual cancer                              Maximum chronic non-cancer
                   risk (in 1 million) \2\    Population      Annual              TOSHI \3\
   Number of    ---------------------------- at risk >=1-     cancer    ----------------------------
 facilities \1\     Actual       Allowable       in-1        incidence      Actual       Allowable        Maximum off-site acute  non-cancer HQ \4\
                   emissions     emissions      million     (cases per     emissions     emissions
                     level         level                       year)         level         level
--------------------------------------------------------------------------------------------------------------------------------------------------------
            19            20            20        15,000         0.002           0.4           0.4   HQREL = 10 formaldehyde.
                                                                                HQAEGL	1 = 0.6 formaldehyde.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Number of facilities evaluated in the risk analysis.
\2\ Maximum individual excess lifetime cancer risk.
\3\ Maximum TOSHI. The target organ with the highest TOSHI for the APR source category is the respiratory system.
\4\ The maximum estimated acute exposure concentration was divided by available short-term threshold values to develop an array of HQ values. HQ values
  shown use the lowest available acute threshold value, which in most cases is the REL. When HQ values exceed 1, we also show HQ values using the next
  lowest available acute dose-response value.

3. What key comments did we receive on the risk review, and what are
our responses?
    For the APR source category, the comments received on the proposed
risk review were generally supportive. A summary of these comments and
our responses can be found in the comment summary and response document
available in the docket for this action (EPA-HQ-OAR-2012-0133).
4. What is the rationale for our final approach for the risk review?
    The results of the revised risk assessment did not significantly
change the maximum risk levels to the most exposed individual for this
source category and did not affect our determinations regarding risk
acceptability and ample margin of safety. The full results of the
revised risk assessment for this source category can be found in the
risk assessment documentation available in the docket for this action
(EPA-HQ-OAR-2012-0133).
    Uncertainty and the potential for bias are inherent in all risk
assessments, including those performed for the source categories
addressed in this final rule. Although uncertainty exists, we believe
that our approach, which used conservative tools and assumptions,
ensures that our decisions are health-protective. A discussion of the
uncertainties in the emissions datasets, dispersion modeling,
inhalation exposure estimates and dose-response relationships is
provided in the preamble to the proposed rule. See 79 FR 1684.
    In accordance with the approach established in the Benzene NESHAP,
the EPA weighed all health risk measures and information considered in
the risk acceptability determination, along with additional factors
relating to the appropriate level of control, including the costs and
economic impacts of emissions controls, technological feasibility,
uncertainties and other relevant factors in making our risk
acceptability and ample margin of safety determination. Considering all
of these factors, the EPA has determined that the risks from the APR
source category are acceptable and that the current MACT standards in
40 CFR part 63, subpart OOO for the APR source category provide an
ample margin of safety to protect public health.

B. Technology Review for the APR Source Category

1. What did we propose pursuant to CAA section 112(d)(6) for the APR
source category?
    For the APR source category, the EPA proposed to change the
thresholds at which emission controls are required for storage vessels
at new sources to be consistent with other storage vessel standards
already required for the chemical industry regulated by the Hazardous
Organic NESHAP for Synthetic Organic Chemical Manufacturing Industry
(HON). We proposed to revise the applicability of the APR new source
MACT standards to include smaller capacity storage vessels and/or
storage vessels containing liquids with lower vapor pressures. An
emissions reduction of 95 percent was proposed for storage vessels of
capacities greater than or equal to 20,000 gal, but less than 40,000
gal if the MTVP is 1.9 psia or greater, and for storage vessels of
capacities greater than or equal to 40,000 gal, but less than 90,000
gal if the MTVP is 0.75 psia or greater. Control was proposed to still
be required for storage vessels of 90,000 gal or greater, if the MTVP
is 0.15 psia or greater, as was previously required for storage vessels
at new sources in the APR source category. See 79 FR 1706-1707.
2. How did the technology review change for the APR source category?
    For the APR source category, the technology review has not changed
since proposal.
3. What key comments did we receive on the technology review, and what
are our responses?
    For the APR source category, the comments received on the proposed
technology review were generally supportive. A summary of these
comments and our responses can be found in the comment summary and
response document available in the docket for this action (EPA-HQ-OAR-
2012-0133).
4. What is the rationale for our final approach for the technology
review?
    The results of the technology review for the APR source category
did not change from proposal. Therefore the EPA is changing the
thresholds at which emission controls are required for storage vessels
at new sources to be consistent with other storage vessel standards
already required for the chemical industry regulated by the HON. An
emissions reduction of 95 percent is now required for storage vessels
of capacities greater than or equal to 20,000 gal, but less than 40,000
gal if the MTVP is 1.9 psia or greater, and for storage vessels of
capacities greater than or equal to 40,000 gal, but less than 90,000
gal if the MTVP is 0.75 psia or greater. Control is still required for
storage vessels of 90,000 gal or greater, if the MTVP is 0.15 psia or
greater, as was previously required for

storage vessels at new sources in the APR source category.

C. Sections 112(d)(2) & (3) Amendments for the APR Source Category

1. What did we propose pursuant to sections 112(d)(2) & (3) for the APR
source category?
    For the APR source category, the EPA identified the absence of an
emissions limit for storage vessels and continuous process vents at
existing APR facilities. Pursuant to CAA sections 112(d)(2) and (3),
for storage vessels, we proposed thresholds at which emission controls
are required consistent with other storage vessel standards already
required for the chemical industry regulated by the HON. An emissions
reduction of 95 percent was proposed for storage vessels of capacities
greater than or equal to 20,000 gal, but less than 40,000 gal if the
MTVP is 1.9 psia or greater, for storage vessels of capacities greater
than or equal to 40,000 gal, but less than 90,000 gal if the MTVP is
0.75 psia or greater, and for storage vessels of 90,000 gal or greater
if the MTVP is 0.15 psia or greater. This represented a beyond-the-
floor level of control for storage vessels at existing facilities.
    Pursuant to CAA sections 112(d)(2) and (3), for continuous process
vents, we proposed that existing facilities reduce organic HAP
emissions either by 85 percent or to a concentration of 20 parts per
million by volume (ppmv), when using a combustion control device, or to
a concentration of 50 ppmv when using a non-combustion control device.
This represented the MACT floor level of control for continuous process
vents at existing facilities. See 79 FR 1701-1703.
2. How did the final amendments pursuant to sections 112(d)(2) & (3)
differ from the proposal for the APR source category?
    For the APR source category, the emissions limit for storage
vessels at existing APR facilities has not changed since proposal.
However, the emissions limit for continuous process vents at existing
APR facilities has been revised to establish an emission limit of 0.95
kg organic HAP/Mg (1.9 lb organic HAP/ton) of resin produced for
continuous process vents.
3. What key comments did we receive on the amendments proposed pursuant
to sections 112(d)(2) & (3) for the APR source category, and what are
our responses?
    The following is a summary of the significant comments received on
the proposed APR emissions limits and our responses to these comments.
The complete list of the comments received and our responses to those
comments can be found in the comment summary and response document
available in the docket for this action (EPA-HQ-OAR-2012-0133).
    Comment: One commenter states that when the EPA developed subpart
OOO, the EPA declined to require controls for spray dryer continuous
process vents for existing sources based on only one of three
facilities with these process vents having emissions controls. The
commenter notes the EPA concluded the MACT floor and existing source
standard was no control, and control was only required for continuous
process vents at new sources. The commenter notes that the EPA is now
proposing standards for existing continuous process vents and states
that the RTR process does not allow for the EPA to reconsider aspects
of previously issued MACT standards unrelated to ``development in
practices, processes and control technologies.'' The commenter states
that the EPA can't merely change its mind about what standards are
required to comply with CAA section 112(d)(2) and (3), nor is it
obligated to recalculate a MACT floor based on subsequent performance.
    Response: The EPA disagrees that we lack the authority to revise
improperly set MACT floors. In Medical Waste Institute v. EPA, 645 F.
3d 420, 425-27 (D.C. Cir. 2011), the United States Court of Appeals for
the District of Columbia Circuit Court held that the EPA may
permissibly amend improper MACT determinations, including amendments to
improperly promulgated floor determinations, using its authority under
section 112(d)(2) and (3). The ``no control'' floor for HAP emitted
from continuous process vents at existing APR sources is not proper.
National Lime, 233 F. 3d at 633-34; see also Medical Waste Institute,
645 F. 3d at 426 (resetting MACT floor, based on post-compliance data,
permissible when the originally-established floor was improperly
established, and permissibility of the EPA's action does not turn on
whether the prior standard was remanded or vacated). Similarly, the
United States Court of Appeals for the District of Columbia Circuit
Court's December 9, 2011, decision in Portland Cement Ass'n v. EPA
(D.C. Cir. No. 10-1358) confirms that the EPA is not constrained by CAA
section 112(d)(6), and it may reassess its standards more often,
including revising existing floors if need be. A full discussion of our
consideration of this issue and basis for determining that the MACT
floor was improperly set is contained the preamble to the proposed rule
at 79 FR 1703 (January 9, 2014).
    Comment: One commenter states that based on its knowledge of the
industry, Georgia Pacific and Tembec are the only companies that
currently manufacture APR and operate APR spray dryer continuous
process vents, but it appears that the original MACT floor
determination and the proposed provisions did not include two other
Georgia Pacific facilities with continuous process vents. The commenter
believes the EPA should revise its MACT floor analyses to include these
facilities. The commenter further requests that if the EPA regulates
emissions from spray dryer continuous process vents, that it establish
an uncontrolled production-based emission limit. The commenter also
requests that in establishing this limit, the EPA allow the calculation
of uncontrolled production-based emissions rates that are based on the
last 5 years of production, which would account for variability in the
drying of multiple resin types.
    Response: The EPA has reviewed the new data submitted by the
commenter and used these data to determine the revised MACT floor for
continuous process vents at existing sources. In reviewing the data,
the EPA determined that a production-based emission limit of 0.95 kg
organic HAP/Mg (1.9 lb organic HAP/ton) of resin produced was
appropriate, as discussed in section IV.C.4.b of this preamble. In
setting this limit, the EPA used emissions data from the previous 5
years submitted by all four affected facilities, which incorporates
sufficient variability in the drying of multiple resin types. For
further details on how the MACT floor was recalculated, see the
technical memorandum titled, MACT Floor and Beyond-the-Floor for
Existing Unregulated Emission Sources in the Amino and Phenolic Resins
Production Source Category, available in the docket for this action.
4. What is the rationale for our final approach for the final
amendments pursuant to sections 112(d)(2) & (3) for the APR source
category?
a. Storage Vessels
    The analysis of the emissions limit for storage vessels at existing
APR facilities has not changed since proposal. Therefore, the EPA is
establishing an emissions limit for storage vessels consistent with
other storage vessel standards already required for the chemical
industry regulated by the HON. An emissions reduction of 95 percent is
required for storage vessels of

capacities greater than or equal to 20,000 gal, but less than 40,000
gal if the MTVP is 1.9 psia or greater, for storage vessels of
capacities greater than or equal to 40,000 gal, but less than 90,000
gal if the MTVP is 0.75 psia or greater, and for storage vessels of
90,000 gal or greater if the MTVP is 0.15 psia or greater.
b. Continuous Process Vents
    The analysis of the emissions limit for continuous process vents at
existing APR facilities has been revised to reflect new data submitted
by industry during the comment period. As part of their comments,
Georgia Pacific identified two additional facilities as having
continuous process vents, bringing the total to four facilities in the
APR source category that have continuous process vents (Tembec in
Toledo, OH, and Georgia Pacific facilities in Crossett, AR,
Taylorsville, MS, and Conway, NC). All but one of the continuous
process vents at these facilities come from dryers on the amino/
phenolic resin process unit (APPU). Based on historical emissions and
production information submitted by these facilities, we have
determined that the MACT floor for continuous process vents is an
emission limit of 0.95 kg organic HAP/Mg (1.9 lb organic HAP/ton) of
resin produced. For further details on how the MACT floor was
calculated for continuous process vents, see the technical memorandum
titled, MACT Floor and Beyond-the-Floor for Existing Unregulated
Emission Sources in the Amino and Phenolic Resins Production Source
Category, available in the docket for this action.
    As part of our beyond-the-floor analysis, we considered control
options more stringent than the MACT floor and identified one such
option. For the beyond-the-floor option, we evaluated the impact of
requiring a 98-percent emissions reduction, assuming that a
regenerative thermal oxidizer would be used to achieve this increased
level of control.
    Table 3 presents the impacts for the MACT floor and the beyond-the-
floor option considered. As seen in Table 3, the MACT floor level of
control is expected to reduce HAP emissions by approximately 135 tpy
and have a cost effectiveness of $6,400/ton of HAP removed. For the
beyond-the-floor option, we estimated the capital costs to be
approximately $9 million, and the total annualized costs are estimated
to be approximately $3 million. The estimated HAP emissions reduction
is approximately 181 tpy, and the incremental cost effectiveness
between the MACT floor and the beyond-the-floor option is approximately
$74,000/ton.
    For further details on the assumptions and methodologies used in
this analysis, see the technical memorandum titled, National Impacts
Associated with the Final NESHAP for Existing Amino and Phenolic Resins
Continuous Process Vents, available in the docket for this action.
    While, as discussed in section V.A above, the continuous process
vent control options are not needed to support the EPA's finding under
CAA section 112(f) that the APR MACT standards already protect public
health with an ample margin of safety, and while we do not factor
quantified risk reductions into CAA section 112(d)(2) beyond-the-floor
analyses, for informational purposes we note that the beyond-the-floor
option for continuous process vents would not reduce the MIR or the
maximum chronic non-cancer TOSHI for the source category because
neither the MIR nor the non-cancer TOSHI is caused by emissions from
continuous process vents.

           Table 3--Nationwide Emissions Reduction and Cost Impacts of Control Options for Continuous Process Vents at Existing APR Facilities
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                Cost         Incremental cost
           Regulatory options              HAP emissions     Capital cost  (million $)      Annual cost  ($/yr)     effectiveness  ($/ effectiveness  ($/
                                          reduction  (tpy)                                                          ton HAP  removed)  ton  HAP removed)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Baseline (MACT floor)..................                135  3.6 million...............  860,000...................              6,400  .................
Beyond-the-floor.......................                181  8.8 million...............  3.1 million...............             17,000             74,000
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Based on this analysis, we do not believe the costs of the beyond-
the-floor option are reasonable, given the level of HAP emissions
reduction that would be achieved with this control option. Therefore,
we are revising the APR MACT standards to require the MACT floor level
of control for continuous process vents at existing APR sources.

VI. What is the rationale for our final decisions and amendments for
the PC source category?

    For each issue, this section provides a description of what we
proposed and finalized for the issue, the EPA's rationale for the final
decisions and amendments and a summary of key comments and responses.
For all comments not discussed in this preamble, comment summaries and
the EPA's responses can be found in the comment summary and response
document available in the docket.

A. Residual Risk Review for the PC Source Category

1. What did we propose pursuant to CAA section 112(f) for the PC source
category?
    For the PC source category, the results of the inhalation risk
assessment indicated the maximum lifetime individual cancer risk could
be up to 0.3-in-1 million, the estimated maximum chronic non-cancer
TOSHI value was 0.04 and the estimated maximum off-facility site acute
HQ value was 2, based on the actual emissions level and the REL value
for triethylamine. The total estimated national cancer incidence from
PC facilities based on actual emission levels is 0.00008 excess cancer
cases per year or one case in every 13,000 years. The EPA proposed that
no amendments were needed for this source category based on the risk
review under CAA section 112(f). See 79 FR 1707-1709.
2. How did the risk review change for the PC source category?
    For the PC source category, the risk review has not changed since
proposal.
3. What key comments did we receive on the risk review, and what are
our responses?
    For the PC source category, the comments received on the proposed
risk review were generally supportive. A summary of these comments and
our responses can be found in the comment summary and response document
available in the docket for this action (EPA-HQ-OAR-2012-0133).
4. What is the rationale for our final approach for the risk review?
    The results of the risk assessment for the PC source category did
not change

from proposal and therefore they did not affect our determinations
regarding risk acceptability and ample margin of safety. The full
results of the risk assessment for the PC source category can be found
in the risk assessment documentation available in the docket for this
action (EPA-HQ-OAR-2012-0133).
    Uncertainty and the potential for bias are inherent in all risk
assessments, including those performed for the source categories
addressed in this final rule. Although uncertainty exists, we believe
that our approach, which used conservative tools and assumptions,
ensures that our decisions are health-protective. A discussion of the
uncertainties in the emissions datasets, dispersion modeling,
inhalation exposure estimates and dose-response relationships is
provided in the preamble to the proposed rule. See 79 FR 1684.
    In accordance with the approach established in the Benzene NESHAP,
the EPA weighed all health risk measures and information considered in
the risk acceptability determination, along with additional factors
relating to the appropriate level of control, including the costs and
economic impacts of emissions controls, technological feasibility,
uncertainties and other relevant factors in making our risk
acceptability and ample margin of safety determination. Considering all
of these factors, the EPA has determined that the risks from the PC
source category are acceptable and that the current MACT standards in
40 CFR part 63, subpart YY for the PC source category provide an ample
margin of safety to protect public health.

B. Technology Review for the PC Source Category

1. What did we propose pursuant to CAA section 112(d)(6) for the PC
source category?
    For the PC source category, the EPA proposed to eliminate the less
stringent of two currently available options for complying with LDAR
program requirements--while retaining the more stringent compliance
requirement. The PC MACT standards previously required compliance with
either subpart TT or subpart UU of 40 CFR part 63 to control emissions
from equipment leaks. As part of the technology review for the PC
source category, we proposed to require facilities to comply with
subpart UU rather than subpart TT, with the exception of connectors in
gas and vapor service and in light liquid service. We proposed to
retain the option to comply with either subpart TT or subpart UU for
those components. See 79 FR 1709-1710.
2. How did the technology review change for the PC source category?
    For the PC source category, the technology review has not changed
since proposal.
3. What key comments did we receive on the technology review, and what
are our responses?
    For the PC source category, the comments received on the proposed
technology review were generally supportive. A summary of these
comments and our responses can be found in the comment summary and
response document available in the docket for this action (EPA-HQ-OAR-
2012-0133).
4. What is the rationale for our final approach for the technology
review?
    The results of the technology review for the PC source category did
not change from proposal. Therefore the EPA is requiring PC facilities
to comply with 40 CFR part 63, subpart UU rather than 40 CFR part 63,
subpart TT, with the exception of connectors in gas and vapor service
and in light liquid service. Facilities continue to have the option to
comply with either subpart TT or subpart UU for those components.

VII. What is the rationale for our final decisions and amendments that
apply to all three source categories?

    For each issue, this section provides a description of what we
proposed and finalized for the issue, the EPA's rationale for the final
decisions and amendments and a summary of key comments and responses.
For all comments not discussed in this preamble, comment summaries and
the EPA's responses can be found in the comment summary and response
document available in the docket.

A. Startup, Shutdown and Malfunction

1. What did we propose for SSM?
    We proposed to eliminate the SSM exemption from all three source
categories and that the existing or revised standards would apply at
all times. We took into account startup and shutdown periods and did
not propose alternate standards for those periods because facilities in
these source categories did not indicate that they would be unable to
comply with the standards during these times and our assessment of the
control technology used confirms that the standards can be met during
periods of startup and shutdown. We also proposed to add provisions for
an affirmative defense to civil penalties for violations of emission
standards in these rules that are caused by malfunctions. See 79 FR
1710-1713.
2. How did the SSM provisions change?
    For the SSM provisions, we are still removing the SSM exemption and
requiring that the existing standards apply at all times. In addition,
we have added language to the AMF and PC MACT standards to clarify that
excused excursions are not allowed. However, we are not finalizing the
proposed affirmative defense provisions.
3. What key comments did we receive on the SSM provisions, and what are
our responses?
    The following is a summary of the significant comments received on
the proposed SSM provisions and our responses to these comments. The
complete list of the comments received and our responses to those
comments can be found in the comment summary and response document
available in the docket for this action (EPA-HQ-OAR-2012-0133).
    Comment: Several commenters state that the proposal to eliminate
the SSM provisions in the proposed subparts is not based on an accurate
reading of the decision of the DC Circuit in Sierra Club v. EPA, 551
F.3d 1019 (D.C. Cir. 2008). The commenters state that the EPA's
proposal for the standards to apply at all times is not consistent with
Sierra Club v. EPA, as the court did not hold that the EPA is
prohibited from setting separate standards for periods of SSM that are
different than the emission limits during normal operations but held
that the standards for those periods must be developed according to the
section 112(d) MACT process and must be proven to be achievable under
section 112(d). The commenters add that there is ample precedent for
the EPA applying a different standard during SSM events, and such a
standard could include a design, equipment, work practice, or
operational standard under section 112(h).
    One of the commenters notes that the definitions of ``emission
limitation'' and ``emission standard'' have included provisions to
limit ``quantity, rate, or concentration of emissions of air pollutants
on a continuous basis'' since 1977, and since that time the EPA has not
required sources to meet NSPS emission limits under CAA section 111
established for normal operations during SSM events. The commenter adds
that Congress enacted the ``continuous basis'' language in section
302(k) knowing the EPA's emission standards under section 111 exempted
SSM periods, and there is nothing in the

legislative history of the 1977 or 1990 amendments to the CAA that
suggests Congress intended to overturn that practice. The commenter
noted that case law has affirmed the appropriateness of including
special SSM provisions in standards issued under section 111.
    Response: The EPA does not claim that the Sierra Club case or the
CAA constrains its authority to prescribe different standards for
periods of startup or shutdown or for periods of malfunction. However,
as explained in the preamble to the proposed and final rules, the EPA
has determined that CAA section 112 does not require that emissions
that occur during periods of malfunction be factored into development
of section 112 standards. The EPA's rationale for this view is
explained in detail in the preamble as well.
    At proposal, we explained that the DC Court had recently vacated
the SSM exemption contained in 40 CFR 63.6(f)(1) and 63.6(h)(1) that
are part of the CAA section 112 General Provisions. Sierra Club v. EPA,
551 F.3d 1019 (D.C. Cir. 2008) cert. denied, 130 S. Ct 1735 (2010). We
further explained that, when incorporated into section 112(d)
regulations for specific source categories, these two provisions exempt
sources from the requirement to comply with otherwise applicable MACT
standards during periods of SSM. We also explained that because these
source categories rely on the General Provisions for SSM provisions, we
were proposing to set standards that apply at all times, including
during malfunctions. The EPA does not claim that the Sierra Club case
constrains its authority to prescribe unique standards for SSM periods.
Rather, the EPA's view is that this decision calls into question the
legality of source category-specific SSM exemptions in rules
promulgated pursuant to section 112.
    Further, in Medical Waste Institute v. EPA, 645 F. 3d 420, 425-27
(D.C. Cir. 2011), the DC Circuit Court held that the EPA may
permissibly amend improper MACT determinations, including amendments to
improperly promulgated floor determinations, using its authority under
section 112(d)(2) and (3). The absence of standards for HAP emitted
during SSM is not proper. National Lime, 233 F. 3d at 633-34; see also
Medical Waste Institute, 645 F. 3d at 426 (resetting MACT floor, based
on post-compliance data, permissible when the originally-established
floor was improperly established, and permissibility of the EPA's
action does not turn on whether the prior standard was remanded or
vacated). Similarly, the DC Circuit Court's December 9, 2011, decision
in Portland Cement Ass'n v. EPA (D.C. Cir. No. 10-1358) confirms that
the EPA is not constrained by CAA section 112(d)(6), and it may
reassess its standards more often, including revising existing floors
if need be. The commenters are, thus, incorrect that CAA section
112(d)(6) provides the exclusive authority to address standards that
apply during SSM events. Here, the EPA adopted no MACT standard at all
for HAP emitted during SSM, an approach soundly rejected by the DC
Circuit Court in National Lime, 233 F. 3d at 633-34. Consequently, we
have revised the standards so the emission limits of the rule apply at
all times, including during periods of SSM. We believe this approach
reasonably accommodates the requirements of the CAA and the Court's
reasoning in Sierra Club.
    The EPA disagrees with commenters' suggestion that the existence of
an SSM exemption in rules implementing CAA section 111 in 1977 when
Congress enacted the ``continuous basis'' language in the definition of
``emission standard'' is evidence that Congress approved of that
regulatory SSM exemption. Commenters fail to cite legislative history
or any other evidence supporting that Congress was aware or approved of
that exemption and the Sierra Club decision makes clear that such
exemptions are inconsistent with the Clean Air Act.
    Comment: One commenter states that the EPA has not justified adding
new ``general duty'' language to the standards and should delete the
new provisions. The commenter also states that the EPA lacks the
authority to replace the previous reference to the General Provisions
with somewhat different language in the individual subparts because
these changes are not being proposed under 112(d)(6) or 112(f).
    Response: The EPA disagrees that it lacks the authority to make the
changes proposed. We have eliminated the SSM exemptions in these three
NESHAP, consistent with Sierra Club v. EPA. As noted previously, the
EPA relies on the CAA and Sierra Club for the elimination of the SSM
exemption. The EPA is not limited to adopting such changes by CAA
sections 112(d)(6) or (f)(2), but retains ongoing authority to revise
its prior adopted section 112(d)(2) and (3)-based standards whenever
the agency identifies a flaw in such standards that renders them
insufficient to meet the requirements of section 112(d)(2). See Medical
Waste Institute v. EPA. The EPA explained in the proposal that we were
adding language to this regulation to replace General Provision
requirements that reference vacated SSM provisions (77 FR 1288, 1299,
1302). The General Provisions ``general duty'' language that was
previously referenced by these NESHAP includes language that is no
longer necessary or appropriate in light of the elimination of the SSM
exemption, so the EPA has modified the general duty requirements that
were contained in 40 CFR 63.6(e) and placed them, modified, in 40 CFR
63.1108(a)(4)(ii) and 63.1400(k)(4). The revised general duty
requirement language reflects the general duty to minimize emissions
while eliminating the reference to periods covered by an SSM exemption.
The current language in 40 CFR 63.6(e)(1)(i) characterizes what the
general duty entails during periods of SSM. With the elimination of the
SSM exemption, there is no need to differentiate between normal
operations, startup and shutdown, and malfunction events in describing
the general duty. Therefore the language the EPA is promulgating does
not include that language from 40 CFR 63.6(e)(1).
    Comment: One commenter states that the past history of the SSM
exemption and compliance problems for these source categories
demonstrates a need for strong and more frequent monitoring, testing,
and reporting requirements and enforcement provisions. The commenter
declares that the EPA must implement enforcement provisions that
prevent and remedy emission spikes, malfunctions, and other violations
in a way that will be enforceable by citizens in the Title V permits
for these source categories. The commenter further states that the EPA
should review the proposed monitoring requirements and ensure they are
stringent enough to enable easy assessment of whether a facility is in
full compliance with the standards within a short period of time of any
violation.
    Response: We believe that the removal of the SSM exemption will
reduce compliance problems that may have been associated with the
exemption and excess emission spikes, as facilities have an incentive
to avoid the related violations and penalties, without the need to
institute more frequent monitoring, testing, and reporting
requirements. We further believe that the monitoring requirements
included in these rules are sufficient to ensure compliance with the
standards regardless of whether or when a violation occurs. Under the
provisions of 40 CFR 63.15, the public can request access to reports
submitted to the regulatory agency whenever they choose, with the
exception of information protected through 40 CFR

part 2 (e.g., confidential business information). In addition, as
discussed in section 4 below, we are promulgating requirements for
electronic reporting of emissions test data that will improve public
access to emissions information.
    Comment: One commenter states that additional requirements are
needed for times of malfunctions, including requirements for automatic
shut-off of malfunctioning equipment, requirements to assign
responsibility to the plant manager or high-up staff member which
allows only that person to restart the equipment, and requirements that
corrective actions be taken immediately. The commenter also states that
for a facility that has had one or more malfunction, exceedance, or
other violation in the prior month, the facility must obtain written
authorization from the EPA to restart the equipment, and the EPA should
only authorize the restart after making a public determination that the
facility has instituted the corrective measures the EPA requires. The
commenter further asserts that for a facility with 4 or more
exceedances or malfunctions in the same quarter, the EPA must require
automatic shutdown of the operation for a period of time to conduct and
publish a full investigation and ensure correction of the problem(s).
    Response: We disagree with the commenter that the suggested
additional requirements regarding malfunctions are necessary. The EPA
believes that the monitoring requirements of the final rule are
sufficient to ensure compliance with the emission standards, and that
it is not necessary to prescribe when or who may restart equipment that
has malfunctioned. With respect to the commenter's suggested reporting
requirements, the reporting requirements in the final rules already
require malfunction reporting. Any such reports submitted to the EPA
are publicly available subject to the requirements of CAA section
114(c).
4. What is the rationale for our final approach for SSM?
    The EPA has determined not to finalize the proposed regulatory
affirmative defense provisions due to a recent ruling by the United
States Court of Appeals for the District of Columbia Circuit, which
vacated an affirmative defense in one of the EPA's Section 112(d)
regulations. NRDC v. EPA, No. 10-1371 (D.C. Cir. April 18, 2014) 2014
U.S. App. LEXIS 7281 (vacating affirmative defense provisions in
Section 112(d) rule establishing emission standards for Portland cement
kilns). For further discussion of the EPA's decision to not include the
affirmative defense provisions in the final rule, see section III.D of
this preamble.
    The EPA has also clarified in the AMF and PC MACT standards that
the excused excursion provisions referenced in 40 CFR part 63, subpart
SS do not apply. An excursion occurs when the value for a monitored
parameter falls outside the established range for that parameter. The
provisions of subpart SS allow for each control device or recovery
device to have one excursion for each semiannual period excused. The
excused excursions were originally put in place to account for
unanticipated operating parameter fluctuations. In keeping with the
Sierra Club decision that emission standards or limitations must be
continuous in nature, we have removed the provisions that would allow
for one violation of the operating conditions for each control or
recovery device to be excused each reporting period.

B. Pressure Relief Devices

1. What did we propose for PRDs?
    For all three source categories, we proposed that a pressure
release of HAP emissions from a PRD in organic HAP service, unless
routed to a control device or process, would be a violation. We also
proposed to require that sources monitor PRDs in organic HAP service
using a device or system that is capable of identifying and recording
the time and duration of each pressure release and of notifying
operators that a release has occurred, unless routed to a control
device, process, fuel gas system or drain system. See 79 FR 1713-1714.
2. How did the PRD requirements change?
    We have clarified that a pressure release of HAP emissions to the
atmosphere from a PRD in organic HAP service is prohibited, unless the
PRD is designed and operated to route all pressure releases to a
control device, process, fuel gas system or drain system. We also made
other minor technical corrections, such as clarifying that the delay of
repair provisions for PRDs after pressure releases still apply, and
exempting PRDs that route to a fuel gas system or drain system from the
PRD monitoring requirements and pressure release prohibition, similar
to the provisions previously contained in subpart UU.
3. What key comments did we receive on the PRD requirements, and what
are our responses?
    The following is a summary of the significant comments received on
the proposed PRD requirements and our responses to these comments. The
complete list of the comments received and our responses to those
comments can be found in the comment summary and response document
available in the docket for this action (EPA-HQ-OAR-2012-0133).
    Comment: Several commenters urge the EPA to withdraw the proposed
amendment that states PRD releases are violations of the standards. At
a minimum, one commenter states that the word ``prohibited'' should be
used rather than ``violation.'' Another commenter suggests this be
rephrased to ``potential malfunction'' rather than ``violation.''
Several commenters state that at most, considering Sierra Club v. EPA,
the EPA should establish work practices or emissions limits for PRDs.
Several other commenters state that emissions from PRD release events
should not be viewed differently than normal process emissions and that
PRD releases should only be prohibited if they result in emissions that
exceed the relevant standards in the rule. Another commenter adds that
the provisions that claim releases are violations are inconsistent with
CAA section 112(r)(7), which allows for the promulgation of release
prevention, detection and correction requirements and with Occupational
Safety and Health Administration (OSHA) requirements for PRDs in its
Process Safety Management regulations.
    Response: The EPA partially agrees with the commenter and has
revised the final PRD provisions to state that emissions of organic HAP
from PRDs to the atmosphere are ``prohibited,'' rather than being a
``violation.'' We disagree, however, with the commenters that the PRD
provisions should be withdrawn or weakened in some way. While several
commenters have suggested replacing the PRD release prohibition with a
work practice standard, it is the EPA's position that separate
standards for periods of malfunction are not appropriate in light of
the 2008 Sierra Club ruling. In order for our treatment of malfunction-
caused emission releases to the atmosphere from PRDs to conform with
the reasoning of the court's ruling, the final rule states that HAP
emission releases to the atmosphere from PRDs in organic HAP service
are prohibited. In any case, no commenters have provided emissions
performance information regarding organic HAP releases to the
atmosphere from PRDs that would enable us to conduct MACT floor and
beyond-floor determinations, even if we believed it was appropriate to
do so and set new standards for these devices, whether numeric or work-
practice.

Similarly, no commenters have provided us with information regarding
the costs of requiring the use of control devices or other means of
emissions limitation for these devices, in lieu of a prohibition of
their releasing HAP to the atmosphere.
    Comment: Several commenters state that there is no applicable
emission limit for PRD releases that would make a pressure release a
violation. One commenter states that PRD releases are specifically
excluded from the process vent definition in the GMACT, and the
equipment leak LDAR limit of 500 ppm that applies when a pressure
release is not occurring. Similarly, another commenter states that the
EPA implies that process vent standards apply to PRDs but does not
provide an explanation or justification for this implication. The
commenter states that the EPA has not demonstrated that emissions from
PRDs were characterized or considered when the process vent standards
for the subject rules were adopted. Another commenter states that since
there is no applicable emission limit for PRD pressure releases, the
CAA does not authorize the proposed PRD monitoring requirements. The
commenter states that the CAA only allows for monitoring to demonstrate
compliance with an emission limit and does not authorize monitoring for
malfunctions. For PRDs in liquid service, the commenter states that
there is an emission limit for PRDs during normal operation in 40 CFR
63.1029 of subpart UU, and the excess emission criterion in the
malfunction definition could be met if the work practice requirements
of that section were not met. The commenter states that a rulemaking is
required to replace the work practice with a prohibition or emission
limit, and the EPA would need to show the proper CAA authority and the
required analyses for the change.
    Response: The final rule language no longer states that a pressure
release from a PRD is a violation, but rather that such organic HAP
releases to the atmosphere are prohibited. The amendments being
finalized for PRD releases do not impose new emission standards for
which a MACT analysis is required by the CAA. Instead, they prohibit
releases to the atmosphere from PRDs in organic HAP service that are no
longer appropriate following the 2008 Sierra Club v. EPA ruling, and
impose additional monitoring requirements to address potential
releases. The prohibition and monitoring requirements do not apply to
PRD release emissions that are captured and routed to a control device,
process, fuel gas system or drain system, since such emissions are not
released to the atmosphere. As stated in the preamble to the proposed
rule, pressure releases from PRDs in organic HAP service occur as a
result of malfunctions, and so with the removal of the SSM exemption,
these releases to the atmosphere may no longer be permitted.
    The commenters are correct in that there already exists an
equipment leak standard for PRDs after a pressure release event, but
there previously existed no provision that prevented a facility from a
having such a pressure release to the atmosphere, nor was there a
provision in place addressing these malfunction-related periods other
than immediately after a pressure release event. The commenter is
correct that there was previously no applicable emission limit in place
for malfunction-caused emissions to the atmosphere from PRDs. As stated
above, however, this does not allow the EPA to permit such malfunction
emissions to remain unaddressed by the final rules. We also disagree
with the commenter that the EPA is not authorized to monitor for