National Emission Standards for Hazardous Air Pollutants for Chemical Manufacturing Area Sources, 4522-4540 [2012-1610]

Agencies

• ENVIRONMENTAL PROTECTION AGENCY

[Federal Register Volume 77, Number 19 (Monday, January 30, 2012)]
[Proposed Rules]
[Pages 4522-4540]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2012-1610]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 63

[EPA-HQ-OAR-2008-0334; FRL-9621-7]
RIN 2060-AQ89


National Emission Standards for Hazardous Air Pollutants for 
Chemical Manufacturing Area Sources

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule; notice of reconsideration of final rule.

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SUMMARY: On October 29, 2009, the EPA promulgated national emission 
standards for the control of hazardous air pollutants for nine area 
source categories in the chemical manufacturing sector: Agricultural 
Chemicals and Pesticides Manufacturing, Cyclic Crude and Intermediate 
Production, Industrial Inorganic Chemical Manufacturing, Industrial 
Organic Chemical Manufacturing, Inorganic Pigments Manufacturing, 
Miscellaneous Organic Chemical Manufacturing, Plastic Materials and 
Resins Manufacturing, Pharmaceutical Production and Synthetic Rubber 
Manufacturing. Following that action, the Administrator received a 
petition for reconsideration. In response to the petition, the EPA is 
reconsidering and requesting comment

[[Page 4523]]

on several provisions of the final rule. The EPA is also proposing 
certain revisions to its approach for addressing malfunctions and 
taking comment on those revisions. The EPA is further soliciting 
comment on the standards applicable during startup and shutdown 
periods, as set forth in the final rule. Additionally, the EPA is 
proposing amendments and technical corrections to the final rule to 
clarify applicability and compliance issues raised by stakeholders 
subject to the final rule.

DATES: Comments. Comments must be received on or before March 30, 2012.
    Public Hearing. If anyone contacts EPA requesting to speak at a 
public hearing by February 9, 2012, a public hearing will be held on 
February 14, 2012. For further information on the public hearing and 
requests to speak, contact Ms. Janet Eck at (919) 541-7946 to verify 
that a hearing will be held. If a public hearing is held, it will be 
held at 10 a.m. at the EPA's Environmental Research Center Auditorium, 
Research Triangle Park, North Carolina, or an alternate site nearby.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-HQ-
OAR-2008-0334, by one of the following methods:
     www.regulations.gov: Follow the on-line instructions for 
submitting comments.
     Email: a-and-r-Docket@epa.gov, Attention Docket ID No. 
EPA-HQ-OAR-2008-0334.
     Fax: (202) 566-9744, Attention Docket ID No. EPA-HQ-OAR-
2008-0334.
     Mail: U.S. Postal Service, send comments to: Air and 
Radiation Docket and Information Center, Environmental Protection 
Agency, Mailcode: 2822T, 1200 Pennsylvania Ave., NW., Washington, DC 
20460, Attention Docket ID No. EPA-HQ-OAR-2008-0334.
     Hand Delivery: In person or by courier, deliver comments 
to: EPA Docket Center (2822T), Room 3334, 1301 Constitution Ave., NW., 
Washington, DC 20004. Such deliveries are only accepted during the 
Docket's normal hours of operation, and special arrangements should be 
made for deliveries of boxed information.
    Instructions: Direct your comments to Docket ID No. EPA-HQ-OAR-
2008-0334. The EPA's policy is that all comments received will be 
included in the public docket without change and may be made available 
online at www.regulations.gov, including any personal information 
provided, unless the comment includes information claimed to be 
confidential business information (CBI) or other information whose 
disclosure is restricted by statute. Do not submit information that you 
consider to be CBI or otherwise protected through www.regulations.gov 
or email. The www.regulations.gov Web site is an ``anonymous access'' 
system, which means the EPA will not know your identity or contact 
information unless you provide it in the body of your comment. If you 
send an email comment directly to the EPA without going through 
www.regulations.gov, your email address will be automatically captured 
and included as part of the comment that is placed in the public docket 
and made available on the Internet. If you submit an electronic 
comment, the EPA recommends that you include your name and other 
contact information in the body of your comment and with any disk or 
CD-ROM you submit. If the EPA cannot read your comment due to technical 
difficulties and cannot contact you for clarification, the EPA may not 
be able to consider your comment. Electronic files should avoid the use 
of special characters, any form of encryption and be free of any 
defects or viruses. For additional information about the EPA's public 
docket, visit the EPA Docket Center homepage at https://www.epa.gov/epahome/dockets.htm.
    Docket: All documents in the docket are listed in the 
www.regulations.gov index. Although listed in the index, some 
information is not publicly available, e.g., CBI or other information 
whose disclosure is restricted by statute. Certain other material, such 
as copyrighted material, will be publicly available only in hard copy. 
Publicly available docket materials are available either electronically 
in www.regulations.gov or in hard copy at the EPA Docket Center, EPA 
West Building, Room 3334, 1301 Constitution Ave., NW., Washington, DC. 
The Public Reading Room is open from 8:30 a.m. to 4:30 p.m., Monday 
through Friday, excluding legal holidays. The telephone number for the 
Public Reading Room is (202) 566-1744, and the telephone number for the 
Docket Center is (202) 566-1742.

FOR FURTHER INFORMATION CONTACT: Mr. Nick Parsons, Refining and 
Chemicals Group (E143-01), Sector Policies and Programs Division, 
Office of Air Quality Planning and Standards, Environmental Protection 
Agency, Research Triangle Park, North Carolina 27711; telephone number: 
(919) 541-5372; fax number: (919) 541-0246; email address: 
parsons.nick@epa.gov.

SUPPLEMENTARY INFORMATION: 
    Organization of this Document. The following outline is provided to 
aid in locating information in this preamble.

I. General Information
    A. Does this notice of reconsideration apply to me?
    B. What should I consider as I prepare my comments to the EPA?
    C. How do I obtain a copy of this document and other related 
information?
II. Background Information
III. Actions We Are Taking
IV. Discussion of Issues for Reconsideration
    A. Title V Permitting Requirements
    B. Requirements When Other Rules Overlap With the Final Rule
    C. Requirement To Conduct Direct and Proximal Leak Inspections
    D. Requirement for Covers or Lids on Process Vessels
    E. Requirement To Conduct Leak Inspections When Equipment Is in 
HAP Service
    F. Applicability of the Family of Materials Concept
V. Requirements During Periods of Startup, Shutdown and Malfunctions 
(SSM)
VI. Requirements for Metal HAP Process Vents
    A. Definition of Metal HAP Process Vent
    B. Metal HAP Process Vent Standards
VII. Technical Corrections and Clarifications
VIII. 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

    A red-line version of the regulatory language that incorporates the 
changes in this action is available in the docket.

I. General Information

A. Does this notice of reconsideration apply to me?

    The regulated categories and entities potentially affected by this 
action include:

[[Page 4524]]



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                                                NAICS
              Industry category               Code \1\               Examples of regulated entities
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Chemical Manufacturing......................       325  Chemical manufacturing area sources that use as
                                                         feedstock, generate as byproduct or produce as product,
                                                         any of the hazardous air pollutants (HAP) subject to
                                                         this subpart except for: (1) Processes classified in
                                                         NAICS Code 325222, 325314 or 325413; (2) processes
                                                         subject to standards for other listed area source
                                                         categories\2\ in NAICS Code 325; (3) certain
                                                         fabricating operations; (4) manufacture of photographic
                                                         film, paper and plate where material is coated or
                                                         contains chemicals (but the manufacture of the
                                                         photographic chemicals is regulated); and (5)
                                                         manufacture of radioactive elements or isotopes, radium
                                                         chloride, radium luminous compounds, strontium and
                                                         uranium.
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\1\ North American Industry Classification System.
\2\ The source categories in NAICS Code 325 for which other area source standards apply are: Acrylic Fibers/
  Modacrylic Fibers Production, Chemical Preparation, Carbon Black, Chemical Manufacturing: Chromium Compounds,
  Polyvinyl Chloride and Copolymers Production, Paint and Allied Coatings and Mercury Cell Chlor-Alkali
  Manufacturing.

    This table is not intended to be exhaustive, but rather provides a 
guide for readers regarding entities likely to be regulated by this 
reconsideration action. To determine whether your facility may be 
affected by this reconsideration action, you should examine the 
applicability criteria in 40 CFR 63.11494 of subpart VVVVVV (National 
Emission Standards for Hazardous Air Pollutants for Chemical 
Manufacturing Area Sources). If you have any questions regarding the 
applicability of the final rule to a particular entity, consult either 
the air permit authority for the entity or your EPA regional 
representative, as listed in 40 CFR 63.13.

B. What should I consider as I prepare my comments to the EPA?

    Submitting CBI. Do not submit information that you consider to be 
CBI electronically through https://www.regulations.gov or email. Send or 
deliver information identified as CBI to only the following address: 
Mr. Nick Parsons, c/o OAQPS Document Control Officer (Room C404-02), 
U.S. Environmental Protection Agency, Research Triangle Park, North 
Carolina 27711, Attn: Docket ID No. EPA-HQ-OAR-2008-0334.
    Clearly mark the part or all of the information that you claim to 
be CBI. For CBI information in a disk or CD-ROM that you mail to the 
EPA, mark the outside of the disk or CD-ROM as CBI and then identify 
electronically within the disk or CD-ROM the specific information that 
is claimed as CBI. In addition to one complete version of the comment 
that includes information claimed as CBI, a copy of the comment that 
does not contain the information claimed as CBI must be submitted for 
inclusion in the public docket. If you submit a disk or CD-ROM that 
does not contain CBI, mark the outside of the disk or CD-ROM clearly 
that it does not contain CBI. Information marked as CBI will not be 
disclosed except in accordance with procedures set forth in 40 CFR part 
2.
    If you have any questions about CBI or the procedures for claiming 
CBI, please consult the person identified in the FOR FURTHER 
INFORMATION CONTACT section.

C. How do I obtain a copy of this document and other related 
information?

    Docket. The docket number for this action and the final rule (40 
CFR part 63, subpart VVVVVV) is Docket ID No. EPA-HQ-OAR-2008-0334.
    World Wide Web (WWW). In addition to being available in the docket, 
an electronic copy of this action is available on the WWW through the 
Technology Transfer Network (TTN) Web site. Following signature, a copy 
of this notice will be posted on the TTN's policy and guidance page for 
newly proposed or promulgated rules at https://www.epa.gov/ttn/oarpg. 
The TTN provides information and technology exchange in various areas 
of air pollution control.

II. Background Information

    Section 112(d) of the Clean Air Act (CAA) requires the EPA to 
establish national emission standards for hazardous air pollutants 
(NESHAP) for both major and area sources of HAP that are listed for 
regulation under CAA section 112(c). A major source is any stationary 
source that emits or has the potential to emit 10 tons per year (tpy) 
or more of any single HAP or 25 tpy or more of any combination of HAP. 
An area source is a stationary source that is not a major source.
    On October 29, 2009 (74 FR 56008), the EPA issued the NESHAP for 
the nine chemical manufacturing area source (CMAS) categories that were 
listed pursuant to CAA sections 112(c)(3) and 112(k)(3)(B). The nine 
area source categories are Agricultural Chemicals and Pesticides 
Manufacturing, Cyclic Crude and Intermediate Production, Industrial 
Inorganic Chemical Manufacturing, Industrial Organic Chemical 
Manufacturing, Inorganic Pigments Manufacturing, Miscellaneous Organic 
Chemical Manufacturing, Plastic Materials and Resins Manufacturing, 
Pharmaceutical Production and Synthetic Rubber Manufacturing.
    CAA section 112(k)(3)(B) directs the EPA to identify at least 30 
HAP that, as a result of emissions from area sources, pose the greatest 
threat to public health in the largest number of urban areas. The EPA 
implemented this provision in 1999 in the Integrated Urban Air Toxics 
Strategy, (64 FR 38715, July 19, 1999) (Strategy). Specifically, in the 
Strategy, the EPA identified 30 HAP that pose the greatest potential 
health threat in urban areas, and these HAP are referred to as the ``30 
urban HAP.'' Section 112(c)(3) of the CAA requires the EPA to list 
sufficient categories or subcategories of area sources to ensure that 
area sources representing 90 percent of the emissions of the 30 urban 
HAP are subject to regulation. The EPA completed this requirement in 
2011 (76 FR 15308, March 21, 2011). The chemical manufacturing area 
source categories were listed to satisfy this requirement for 15 of the 
30 urban HAP.\1\ Pursuant to CAA section 112(d)(5), the NESHAP reflect 
generally available control technologies or management practices 
(GACT). The NESHAP apply to each chemical manufacturing process unit 
(CMPU) that uses, generates or produces any of the 15 urban HAP for 
which the area source categories were listed (collectively ``chemical 
manufacturing urban HAP'' or ``Table 1 HAP'').
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    \1\ The 15 urban HAP for which the chemical manufacturing area 
source categories were listed are identified in table 1 of the final 
rule.
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    On February 12, 2010, following promulgation of the final rule, the 
EPA received a petition for reconsideration from the American Chemistry 
Council (ACC) and the Society of Chemical Manufacturers & Affiliates 
(SOCMA) (``Petitioners''). A copy of this petition is provided in the 
docket (see Docket ID No. EPA-HQ-OAR-2008-0334). Petitioners, pursuant 
to CAA section 307(d)(7)(B), requested that the EPA

[[Page 4525]]

reconsider six provisions in the rules: (1) The requirement that major 
sources that installed air pollution controls after 1990, and, as a 
result, became area sources, obtain a title V permit; (2) the 
requirement that sources subject to the final rule and any overlapping 
provision in another rule comply with each provision independently, or 
with the most stringent requirements of each rule; (3) the requirement 
that leak inspections include direct and proximal (thorough) inspection 
of all areas of potential leak within the CMPU; (4) the requirement 
that process vessels in HAP service be equipped with a cover or lid 
that must be in place at all times when the vessel contains HAP, except 
for material addition and sampling; (5) the requirement to conduct leak 
inspections while the equipment is in HAP service; and (6) the 
requirement that a CMPU include all equipment and processes used to 
produce a ``family of materials.'' The arguments in support of these 
requests are provided in the petition and described briefly below. 
Petitioners also requested that the EPA stay the effectiveness of these 
provisions of the rule to save many facilities from needlessly having 
to file the initial notifications required by the final rule.
    On June 15, 2010, the EPA sent a letter to Petitioners informing 
them that the EPA was granting the request for reconsideration on at 
least one issue raised in the petition, and that the agency would 
identify the specific issue or issues for which it was granting 
reconsideration in the reconsideration notice that would be published 
in the Federal Register. The letter also indicated that the EPA 
considered the request for a stay to be moot because the due date for 
initial notifications had already passed.

III. Actions We Are Taking

    In this notice, we are granting reconsideration of, and requesting 
comment on, the six issues raised by Petitioners in their petition for 
reconsideration. Section IV of this preamble summarizes these issues 
and discusses our proposed responses to each issue.
    We are also proposing additional provisions related to malfunctions 
and requesting comment on the provisions in the final rule that address 
periods of startup and shutdown. We are also proposing amendments to, 
and taking comment on, the standards applicable to metal HAP process 
vents. Finally, we are proposing technical corrections to certain 
applicability and compliance provisions in the final rule.
    We are seeking public comment only on the issues specifically 
identified in this notice. We will not respond to any comments 
addressing other aspects of the final rule or any other related 
rulemakings.

IV. Discussion of Issues for Reconsideration

    This section of the preamble contains the EPA's basis for our 
proposed responses to the issues identified in the petition for 
reconsideration. We solicit comment on all proposed responses and 
revisions discussed in the following sections.

A. Title V Permitting Requirements

    The EPA proposed to exempt all chemical manufacturing area sources 
from the requirement to obtain a title V permit. In the final rule, in 
response to comments and after a full review of the record, the EPA 
stated that it was not finalizing the exemption for major sources that 
became synthetic area sources by installing air pollution controls 
after 1990. Among other things, the agency explained that we made the 
change, in part, because we failed to consider the large number of such 
sources in proposing the exemption, and because these sources had 
uncontrolled emissions that made them much more like major sources. See 
74 FR 56013, October 29, 2009. Petitioners maintain that the proposed 
exemption of CMAS facilities from title V permitting requirements was 
fully and correctly justified in the preamble to the proposed CMAS 
rule. The Petitioners also claim:
     The EPA's assertion in the final rule that facilities that 
installed control equipment to become synthetic area sources are 
``generally larger and more sophisticated'' than other chemical 
manufacturing area sources contradicts our earlier finding in the 
proposed rule that many of the facilities that would be affected by the 
CMAS rule are small entities without the resources to comply with 
permitting requirements. The Petitioners also state that approximately 
87 percent of SOCMA members and 45 percent of ACC members are small 
businesses, which they cite as support for the proposed finding.
     The final rule fails to recognize that, in order for a 
facility to be treated as a synthetic area source due to the 
installation of controls, the facility has a legal duty to use the 
equipment because the control requirement must be federally 
enforceable. Further, the Petitioners state that, ``In order to have 
been approved by the EPA, a state operating permit program that imposes 
a federally enforceable requirement to use control equipment must 
provide the public with notice and an opportunity to comment on draft 
permits * * * and must also provide for emissions reporting and public 
availability of reported information.''
     The final rule is contrary to the decision in Alabama 
Power Co. v. EPA, which held that a source's potential to emit is 
determined by its design capacity and the anticipated functioning of 
the air pollution control equipment. Thus, the petitioners claim that 
whether a facility is a natural area source or a synthetic area source 
(due to either operational limits or the use of control devices) should 
not matter for regulatory purposes.
     The EPA argued in the area source rules for asphalt 
processing/asphalt roofing manufacturing, and paint and allied products 
manufacturing, that state-delegated programs are sufficient to assure 
compliance, and that it is not more difficult for citizens to enforce 
the NESHAP absent a title V permit. According to the Petitioners, these 
statements are equally, if not more, true for chemical manufacturing 
synthetic area sources.
     Title V requirements will impose substantial transactional 
and compliance costs on subject facilities, and limit their flexibility 
to respond to market opportunities.
    In conclusion, Petitioners suggest that we should exempt all 
chemical manufacturing area sources from the requirement to obtain a 
title V permit consistent with the proposed rule. We reviewed our 
rationale, as stated in the preamble to the final rule (74 FR 56013-
56014) and summarized below, for the final title V permitting 
requirement for facilities that became synthetic area sources by virtue 
of installing air pollution control devices after 1990. We continue to 
believe that requiring title V for synthetic area sources that 
installed controls to become area sources is appropriate; therefore, we 
are not proposing to exempt such sources from the requirement to obtain 
a title V permit. We are, however, making changes to the applicability 
of the provision at issue. Instead of requiring a title V permit for 
all synthetic area sources that installed air pollution controls in 
order to become an area source, regardless of whether the controls were 
installed on an affected CMPU, we are now proposing to only require a 
title V permit for a synthetic area source if air pollution controls 
were installed on at least one CMPU subject to the final rule in order 
to become an area source. Such a limitation would be consistent with 
the standards in the final rule that are applicable only to the CMPU 
that emit one of the chemical manufacturing urban HAP. We are also

[[Page 4526]]

proposing to add provisions that inform sources when they must submit a 
title V permit application consistent with the title V regulations at 
40 CFR part 70 and 40 CFR part 71.
    Pursuant to section 502(a) of the CAA, the Administrator may 
``exempt one or more [area] source categories (in whole or in part) 
from the requirements of [title V] if the Administrator finds that 
compliance with such requirements is impracticable, infeasible, or 
unnecessarily burdensome * * * .'' In December 2005, in a national 
rulemaking, the EPA interpreted the term ``unnecessarily burdensome'' 
in CAA section 502, and developed a four-factor balancing test for 
determining whether title V is unnecessarily burdensome for a 
particular area source category, such that an exemption from title V is 
appropriate. See 70 FR 75320, December 19, 2005 (Exemption Rule). The 
EPA evaluated the chemical manufacturing area source categories 
pursuant to the four-factor balancing test in the proposed rule, and 
determined that title V permitting was unnecessarily burdensome. 73 FR 
58371-58373. However, as stated above, the EPA did not finalize the 
exemption for synthetic area sources that became area sources by 
installing air pollution controls after November 15, 1990, in part, 
because the agency failed to consider the large number of such sources 
in proposing the exemption. 74 FR 56013. We explained the reasons for 
our oversight, and then concluded that title V was not unnecessarily 
burdensome and provided a reasoned basis for that conclusion, as 
discussed below. 74 FR 56013-56014.
    In the preamble to the final rule, we noted that the chemical 
manufacturing area source categories are different from other area 
source categories we have exempted because the categories include a 
large number of synthetic area sources (major sources that installed 
air pollution controls to become area sources) and the sources in the 
other categories generally have very low emissions of HAP before 
control. We then stated that at least 10 percent of the estimated 75 
facilities that are synthetic area sources for HAP by virtue of 
installing controls have uncontrolled HAP emissions over 100 tpy. We 
also indicated that our information showed that many of the sources are 
located in cities, and often in close proximity to residential and 
commercial centers where large numbers of people live and work. We 
further stated that these synthetic area sources have significantly 
higher emissions potential when uncontrolled than the other sources in 
the chemical manufacturing area source categories, and that they are 
much more like the major sources of HAP subject to the Hazardous 
Organic Chemical Manufacturing NESHAP (HON) and the Miscellaneous 
Organic Chemical Manufacturing NESHAP (MON). For these reasons, and 
other reasons set forth in the preamble to the final rule, we 
determined that ``requiring additional public involvement and 
compliance assurance requirements through title V is important to 
ensure that these sources are maintaining their emissions at the area 
source level, and, while there is some burden on the affected 
facilities, we think that the burden is not significant because these 
facilities are generally larger and more sophisticated than the natural 
area sources and sources that took operational limits to become area 
sources.'' 74 FR 56014.
    Contrary to the Petitioners' first assertion, we do not believe 
that there is a conflict between our finding that many CMAS facilities 
are small entities that lack the technical and financial resources to 
comply with title V, and our finding that CMAS facilities that are 
synthetic area sources due to the use of control devices are generally 
larger and more sophisticated than other facilities covered by the 
final rule. The fact that nearly all SOCMA members are small businesses 
does not, by itself, counter these findings. As we stated in the 
preamble to the final rule, an estimated 450 CMAS facilities have 
processes that would be subject to the rule. Of those, we estimated 
that 75 are synthetic area sources by virtue of add-on controls, and 
only 47 of these facilities were estimated to need a new title V permit 
because the remainder of the sources are already subject to title V for 
other reasons. Of the 47 sources that would require a new title V 
permit under the requirement in the final rule, we estimated that at 
least two-thirds of these facilities are large entities. Since we do 
not know whether the add-on controls at these 75 facilities are 
installed on a CMPU subject to the final rule, we cannot estimate the 
total number of facilities that would be required to obtain a new title 
V permit under this proposed revision to the title V permit 
requirement. However, we believe that it would be less than the 47 
facilities that would have required a new title V permit under the 
final rule requirement. Based on information from SOCMA, approximately 
270 member companies are small businesses. However, it is not clear how 
many of these companies have facilities that are subject to the CMAS 
rule, how many of the subject facilities are synthetic area sources for 
HAP emissions due to the use of control devices or how many of the 
synthetic area sources for HAP emissions are subject to title V 
permitting requirements for other reasons. The information provided by 
Petitioner ACC is similarly vague on this issue.
    The Petitioners also argue that the title V requirement is not 
appropriate because: (1) State operating permits that impose a 
federally enforceable requirement must provide the public with notice 
and the opportunity to comment on the draft permit; (2) synthetic area 
source limits must be federally enforceable pursuant to the definition 
of ``potential to emit'' at 40 CFR 63.2, and that it should not matter 
whether an area source is synthetic or natural; (3) the EPA has 
determined in other area source rules that state-delegated programs and 
Federal enforceability of the standards is sufficient, and that 
determination is equally applicable to the area sources subject to 
title V in this rule; and (4) the requirement to obtain a title V 
permit will impose substantial compliance costs and reduce flexibility 
at the subject facilities. We are not proposing changes to the title V 
permitting requirement based on these arguments because we do not 
believe that they support a change in our position. First, while it is 
true that the EPA regulations require Federal enforceability of 
limitations on potential to emit HAP, Petitioners did not provide any 
information as to the level of public participation required to obtain 
such limits and whether the level of participation was as comprehensive 
as that required pursuant to title V. Even if Petitioners could 
demonstrate that the level of public participation was comparable to 
that required under title V, our determination would not be altered on 
that issue alone because title V has other important requirements that 
may not apply to synthetic area sources that are not subject to title V 
(e.g., the requirement to annually certify compliance with all 
applicable requirements). Second, the EPA disagrees that natural and 
synthetic area sources must be treated the same. As stated in the 
preamble to the final rule, ``[synthetic area source] facilities are 
generally larger and more sophisticated than the natural area sources 
and sources that took operational limits to become area sources'' (74 
FR 56014). Third, we explained in the preamble to the final rule that 
the chemical manufacturing area sources are not similar to other area 
source categories that we have exempted because of the

[[Page 4527]]

large number of synthetic area sources that installed add-on controls 
and the high volume of pre-control device HAP emissions from the 
chemical manufacturing area sources that added controls as compared 
with other area sources. As these synthetic area sources have 
essentially the same pre-control device HAP emissions potential as a 
major source chemical manufacturing facility, we believe that the title 
V permit requirement will help ensure that these control devices remain 
in place and that these sources maintain their area source status. 
Since it is possible that the non-operation, failure or 
underperformance of a single control device could result in a source 
within this category exceeding the major source emission threshold (10 
tpy or more of any single HAP or 25 tpy or more of any combination of 
HAP), we believe that the additional scrutiny that permitting 
authorities place on sources with title V permits is warranted. 
Finally, Petitioners have provided no information that demonstrates 
that the cost of compliance for affected facilities will, in fact, 
significantly burden the sources subject to the title V requirement, or 
that such requirement will limit operational flexibility. We request 
comments and information that address these issues, including 
information and requirements that are required by state operating 
permit programs, so that we can more thoroughly evaluate applicability 
of title V for the identified sources.
    As stated above, we are proposing changes to the applicability of 
the title V permit requirement to synthetic area sources that installed 
controls. The proposed changes more clearly identify the sources 
subject to title V as those that route (or have routed) emissions from 
at least one process unit subject to the final rule to a control 
device(s) that is required to maintain synthetic area source status at 
the facility, which will likely reduce the number of sources required 
to obtain a title V permit, if promulgated. Specifically, because the 
standards apply only to CMPU that meet the specific applicability 
criteria in the rule, we request comment on whether the title V 
permitting requirement should be applicable only if one or more of the 
CMPU that are subject to the final standards are controlled by the air 
pollution control equipment necessary for the facility to maintain area 
source status. We are also proposing to include language that informs 
sources subject to title V requirements when they must submit a title V 
permit application. The EPA is including these new provisions because, 
on March 14, 2011, the agency issued a final rule staying the 
requirement to obtain a title V permit until the final reconsideration 
rule is published in the Federal Register. 76 FR 13514. Because the 
stay will be lifted once the final rule is published in the Federal 
Register, we determined it was necessary to include an application 
deadline for those existing sources currently subject to the final rule 
to avoid confusion as to when title V permit applications would be due. 
The proposed application deadline for existing sources provides the 
full 12 months otherwise available to sources newly subject to title V 
pursuant to the EPA regulations at 40 CFR part 70 and 40 CFR part 71. 
See 40 CFR 70.5(a)(1) and 40 CFR 71.5(a)(1). We also propose to include 
a provision indicating the time available for new sources and existing 
sources that become subject to the rule after the effective date to 
submit a title V permit application.\2\ We solicit comment on these 
proposed changes to the final rule.
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    \2\ Existing sources may become subject to the NESHAP for CMAS 
after the effective date of the standards because the final rule 
bases applicability on the use of chemical manufacturing urban HAP 
(Table 1 HAP) in a CMPU. 40 CFR 63.11494. If a source begins using a 
Table 1 HAP after the effective date, the facility will be subject 
to the CMAS standards, and, if the source is a synthetic area source 
that installed controls, the source will be subject to title V.
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    Additionally, we are soliciting comment on the promulgated final 
rule requirement that required a facility to obtain a title V permit if 
emissions from any process unit are (or have been) routed to the 
control device(s) that is required to maintain synthetic area source 
status at the facility.
    We are requesting comment with supporting rationale on the 
requirement, as specified in this proposed rule and the promulgated 
final rule requirement outlined above. We are also interested in 
information that would allow us to better estimate the burden under the 
requirement in this proposed rule and the alternative. For example, we 
are interested in results of any surveys that document: (1) The 
percentage and/or number of CMAS facilities that are synthetic area 
sources for HAP emissions because they use federally-enforceable 
control devices; (2) the percentage and/or number of such facilities 
that are using the control devices to control emissions from at least 
one CMAS CMPU; (3) the financial burden of obtaining a title V permit 
compared to sales; and (4) the percentage and/or number of such 
facilities that are not already subject to title V requirements for 
other reasons. We are not taking comment on our decision in the final 
rule to exempt from title V chemical manufacturing areas sources that 
are natural area sources or that took operational limits to become area 
sources.

B. Requirements When Other Rules Overlap With the Final Rule

    Petitioners note that their comments on the proposed rule urged the 
EPA to include provisions in the final rule that would minimize the 
burden associated with overlapping provisions between the CMAS rule and 
other rules. Specifically, they recommended that the CMAS rule include 
provisions to allow a facility subject to the CMAS rule and any other 
applicable area or major source rule to opt to comply with either, and 
noted that such an approach has been taken in many other rules. In 
response to those comments, we added provisions to address overlapping 
requirements in the final rule. See 40 CFR 63.11500. However, 
Petitioners consider the overlapping rule requirements in the final 
rule, which specify that a facility may elect to comply with the most 
stringent provisions of the applicable rules as an alternative to 
complying fully with each rule independently, to be ``unprecedented, 
burdensome, and highly problematic.'' According to the Petitioners, 
concerns with the alternative are that: (1) There can be uncertainty 
regarding which provision is more stringent; (2) facilities will be at 
risk that the EPA or a delegated authority will subsequently disagree 
with the source's determination; and (3) the effort necessary to 
construct a matrix of applicable requirements and determine which are 
the most stringent will exceed available staff and financial resources 
of many area sources. In addition, Petitioners state that complying in 
every respect with two overlapping rules is bound to involve 
substantial duplication, and, in some cases, may not be possible due to 
conflicts between the two rules. For these reasons, Petitioners 
recommend that we either propose to eliminate the final language or 
request comment on it.
    We disagree with the Petitioners' assertion that the requirements 
in the final rule are unprecedented and procedurally invalid. In the 
absence of the language in the final rule, a facility would be required 
to comply with all applicable requirements in both the CMAS rule and 
all other applicable rules, regardless of whether some equipment is 
subject to more than one rule. The final CMAS rule merely made explicit 
the implicit requirement to comply with all applicable standards. It 
was in response to Petitioners' comments that the agency provided an

[[Page 4528]]

overlapping requirements alternative that allows a facility to identify 
and comply with only one set of requirements (i.e., the most stringent 
requirements in the overlapping rules). The alternative was intended as 
a means of reducing the compliance burden without diminishing the level 
of environmental protection provided by each rule.
    We did not include language that defines the more stringent 
requirements, as found in other rules, due to the great variety in 
characteristics of CMAS processes and the wide variety of compliance 
options in both the CMAS rule and overlapping rules. This variety makes 
it difficult to develop language that would not inadvertently allow a 
CMAS facility to comply with requirements less stringent than those 
contained in 40 CFR part 63, subpart VVVVVV, or less stringent than the 
required control level in an overlapping rule. Furthermore, as noted in 
the economic and control cost impacts analyses (see Docket ID No. EPA-
HQ-OAR-2008-0334-0079), we expect that most CMAS facilities will be 
subject to only the management practices in subpart VVVVVV. For those 
sources, we anticipate that it generally will not be difficult or 
burdensome to determine which requirements in subpart VVVVVV and an 
overlapping rule are the most stringent. For those sources that are 
unable to determine the more stringent requirement between subpart 
VVVVVV and an overlapping requirement, we believe it would be more 
appropriate to address those situations on a case-by-case basis.
    We are granting reconsideration of the overlapping provisions 
requirement in 40 CFR 63.11500 of the final rule to allow comment on 
both the language in the final rule and any alternative suggestions. 
Specifically, we are interested in language that would reduce the 
compliance burden for the CMAS rule and any overlapping rules combined, 
yet assure that all requirements in the CMAS rule are met. We are also 
interested in specific examples of requirements in overlapping rules 
that conflict with requirements in the CMAS final rule.

C. Requirement To Conduct Direct and Proximal Leak Inspections

    In the final rule, the EPA revised the provision for inspections to 
require that facilities conduct a ``direct and proximal (thorough) 
inspection of all areas of potential leak within the CMPU.'' 
Petitioners object to the requirement in the final rule to conduct 
``direct and proximal (thorough)'' inspections because they believe it 
requires inspections without regard to safety or difficulty of access. 
Petitioners also note that areas that are difficult to inspect or 
unsafe to inspect or monitor are exempted from regular inspection 
requirements in other rules, and they point out that, in their comments 
on the proposed CMAS rule, they requested clarification that sensory 
inspections may be done from a distance when equipment is either 
inaccessible or unsafe for close visual inspection. Therefore, 
Petitioners maintain that the agency should either propose to eliminate 
the direct and proximal inspection requirement or request comment on 
it.
    We have determined that the inspections required in the final rule 
require control that is more stringent than GACT because we are not 
aware of any facility conducting direct and proximal inspections of all 
process vessels and equipment. For this reason, and to address 
Petitioners' concerns, we are proposing to delete the requirement for 
direct and proximal inspections. However, we want to assure that 
sensory inspections be performed at distances such that the results are 
meaningful.
    As a result, we are proposing that the amended rule would specify 
that a facility must conduct quarterly sensory inspections of all 
equipment and process vessels, provided these methods are capable of 
detecting leaks within the CMPU (i.e., the inspector is within 
sufficient proximity to the equipment that leaking equipment can be 
detected by sight, sound or smell). We are not, however, proposing to 
exempt equipment that is difficult or unsafe to monitor. Rules that 
provide such exemptions do so because they require instrument 
monitoring that relies on being able to locate the instrument probe 
very close to the equipment being inspected (e.g., see 40 CFR part 63, 
subparts TT and UU). Sensory monitoring does not require intimate 
contact with each piece of equipment to be effective at identifying 
leaks. In addition, due to the wide variety of design and operating 
conditions throughout the source category, we also are not proposing 
criteria regarding an acceptable distance for inspection or the types 
of conditions under which the inspection may be conducted from a 
distance. Our intent is that each facility should conduct inspections 
as close as practical to the equipment to be able to detect leaks while 
also following procedures contained in site-specific safety plans. The 
proposed requirements would be consistent with sensory inspection 
requirements in 40 CFR part 63, subpart R. We request comment on both 
the direct and proximal language in the final rule and these proposed 
revisions.

D. Requirement for Covers or Lids on Process Vessels

    We proposed to require process vessels in HAP service be closed 
``except when operator access is necessary.'' 73 FR 58377 (proposed 40 
CFR 63.11495(a)). The final rule requires process vessels in HAP 
service to be equipped with a cover or lid that must be in place at all 
times when the vessel contains HAP, ``except for material addition and 
sampling.'' 40 CFR 63.11495(a)(1). Petitioners contend that compliance 
with this management practice requirement is impossible due to safety 
issues and because it does not consider the need to take material out 
of a vessel or to conduct maintenance. Petitioners are particularly 
concerned that the requirement does not appear to allow openings for 
any type of maintenance, even after the process is shut down, and only 
trace levels of HAP are present. In subsequent correspondence, 
Petitioners suggest that their concerns would be resolved if we modify 
the rule so that the cover or lid requirement applies only when a 
process vessel is ``in use'' (which is a concept that they state can be 
easily applied), and clarify that ``in use'' does not include routine 
cleaning operations. See Docket ID No. EPA-HQ-OAR-2008-0334. 
Petitioners explain that the exclusion for cleaning is needed because 
the definition of a ``chemical manufacturing process'' includes routine 
cleaning operations, but vessels must be opened for cleaning. 
Therefore, the Petitioners state that we should either propose changes 
that would require the use of covers or lids only when subject process 
vessels are in use, or seek comments on the requirement as written in 
the final rule.
    We are granting reconsideration of the requirement to use a cover 
or lid on process vessels because the Petitioners comments indicate 
that the requirement can be interpreted as requiring control more 
stringent than we intended. The proposed rule specified that ``all 
process equipment in which organic HAP is used to process material must 
be covered when in use, and closure mechanisms on other openings and 
access points in process equipment must be in the closed position 
during operation, except when operator access is necessary.'' 73 FR 
58377 (proposed 40 CFR 63.11495(a)). The intent of the requirement for 
covers in the proposed rule was to ensure that processes do not operate 
with open-top vessels. The purpose of the cover is to minimize

[[Page 4529]]

emissions from surface evaporation, but not necessarily to have a tight 
seal between the cover and the vessel. For the final rule, we tried to 
clarify what ``in use'' and ``operator access'' meant by specifying 
that the cover (or lid) ``must be in place at all times when the vessel 
contains HAP, except for material addition and sampling.'' However, as 
the Petitioners have pointed out, the revised language can be 
interpreted as prohibiting removal of the cover, even when only traces 
of HAP remain in the vessel after it has been drained, which would 
prohibit opening to perform maintenance or manual cleaning. Requiring 
use of the cover in this way is not GACT, and it was not our intent.
    To address the Petitioners' issues, we are proposing to revise 40 
CFR 63.11495(a)(1) in the final rule to read as follows: ``Each process 
vessel must be equipped with a cover or lid that must be closed 
whenever the vessel is in organic HAP service or metal HAP service, 
except for manual operations that require access, such as material 
addition and removal, inspection, sampling, and cleaning.'' We note 
that allowing opening of a process vessel for material removal 
clarifies that process vessels, such as filter presses, may be opened 
in order to remove the filter cake.
    The proposed change also would exempt manual cleaning operations 
from the requirement to maintain closed covers and lids while a process 
vessel is in organic HAP or metal HAP service. As the Petitioners 
noted, the definition of ``chemical manufacturing process'' is drawn 
from the definition of a ``miscellaneous organic chemical manufacturing 
process'' in 40 CFR 63.2550 of the MON. That definition includes 
``routine cleaning operations,'' which are described in the preamble to 
the final MON as ``cleaning conducted within enclosed equipment between 
batches or between campaigns.'' The MON preamble goes on to state that 
these operations ``often consist of conducting solvent rinses through 
the equipment,'' and emissions are characterized as part of the 
emissions from a batch process vent. See 68 FR 63860, November 10, 
2003. Contrary to Petitioner's assertion, this type of cleaning was 
included as part of the process specifically because we considered the 
vessels to be ``in use'' while it is conducted. We also consider 
vessels to be in use when manual cleaning is performed. To clarify this 
point, we are proposing to revise the definition of ``chemical 
manufacturing process'' to specify that all cleaning activities are 
part of the process. However, because GACT does not include the use of 
closed covers and lids when performing manual cleaning, we are 
proposing two additional changes. First, we are proposing the change 
noted above to exempt manual cleaning operations from the requirement 
to maintain covers and lids in the closed position when the vessel is 
in organic HAP service or metal HAP service. Second, we are proposing 
to revise the definition of ``in organic HAP service'' to specify that 
a process vessel is no longer in organic HAP service after the vessel 
has been emptied to the extent practicable (i.e., a vessel with liquid 
left on process vessel walls or as bottom clingage, but not in pools, 
due to floor irregularity, is considered completely empty), and any 
cleaning has been completed. We expect emissions to be minimal during 
manual cleaning operations and when a process vessel is no longer in 
organic HAP service. We are not proposing any changes to 40 CFR 
63.11494(a)(1) regarding maintenance activities because those 
activities would be conducted after the vessel has been drained (and 
possibly cleaned) and the vessel would no longer be in organic HAP 
service.
    We request comments on both the provisions, as specified in the 
final rule and the proposed changes. Specifically, we request comment 
on whether the proposed changes effectively address the issues raised 
by Petitioners, and clarify the requirements without introducing 
unintended consequences. We also request comment on whether a change 
like that proposed for the definition of ``in organic HAP service'' is 
needed for the definition of ``in metal HAP service.'' In particular, 
we request comment on whether a change is needed to address when 
vessels that contain metal HAP in the form of particulate are in use, 
and, if so, we request information on the types of vessels for which 
the change is needed and recommendations on how the language in the 
definition could be structured. We are also requesting comment on 
possible changes to the requirements for cleaning that would include 
requirements for manual cleaning as well as for automated rinses 
through closed equipment.

E. Requirement To Conduct Leak Inspections When Equipment Is in HAP 
Service

    Petitioners state that ``the final rule can be read to imply that 
the equipment must be in HAP service when the inspection is 
conducted.'' Petitioners note that this is in contrast to the proposed 
rule, which would have required quarterly inspections without 
specifying any other conditions. Petitioners stated that they did not 
comment on the proposed language because they considered it to be 
reasonable; however, Petitioners contend that the apparent requirement 
in the final rule is problematic because batch processors who operate 
equipment in HAP service for short periods of time and have limited 
operating personnel may find it difficult to accomplish the required 
inspections during these narrow windows of time. Petitioners ask for 
clarification about whether this interpretation is correct, and, if it 
is, Petitioners state that we should either propose reverting to the 
proposed language, or propose language allowing quarterly leak 
detection and repair inspections when the equipment is in volatile 
organic compound (VOC) service, not just HAP service.
    Based on our review of this issue, we are proposing some editorial 
changes to 40 CFR 63.11495(a)(3) of the final rule to make the rule 
easier to read and understand. These changes are described in Section 
VII of this preamble. However, we decided not to propose changes as 
suggested by the Petitioners because we have several concerns regarding 
how inspections can be conducted effectively when the process is not 
operating in HAP service. We request comment on both the specific 
concerns described below, as well as all other aspects of the 
requirements in the final rule related to the timing of inspections. 
First, because the configuration of process vessels and equipment 
likely changes from one CMPU to the next, we request comment on how 
sources would track which vessels and equipment to inspect in VOC 
service if we adopted Petitioners' approach and whether this effort 
would negate any advantages of having flexibility to inspect at times 
other than when the subject CMPU is operating in organic HAP service. 
Second, process vessels are generally opened and cleaned when 
reconfiguring to create a different CMPU, and equipment connections are 
also often opened. Therefore, we also request comment discussing how 
inspections in VOC service for a different configuration would provide 
information that is relevant to determining whether there are leaks 
from the subject CMPU. Finally, if someone elects to conduct Method 21 
monitoring rather than sensory inspections, the instrument reading 
obtained would be related to the concentration of organic compound in 
the fluid and the response factor of the instrument for that organic 
compound. Thus, we request comment on the need to specify criteria for 
the type of fluid

[[Page 4530]]

that may be used when conducting inspections of vessels and equipment 
in VOC service (e.g., that the VOC concentration must be no less than 
the total organic compound concentration in the subject CMPU when in 
organic HAP service). We will consider adopting the Petitioners' 
approach after reconsideration if we can adequately address these 
issues.

F. Applicability of the Family of Materials Concept

    After proposal, the rule was revised in response to comments from 
Petitioners and others that argued applicability should be established 
on a CMPU basis instead of facility-wide basis. Petitioners 
specifically suggested that the EPA adopt the CMPU construct. We 
defined the CMPU in the final rule to include ``all process vessels, 
equipment, and activities necessary to operate a chemical manufacturing 
process that produces a material or family of materials * * *. A CMPU 
consists of one or more unit operations and any associated recovery 
device.'' 40 CFR 63.11494(b). In adopting the CMPU construct, we 
determined that, to adequately characterize the CMPU, the applicability 
of the rule should extend to the ``family of materials'' because the 
CMPU concept is derived from the MON, and production of a family of 
materials is part of a single process unit in the MON. Furthermore, as 
in the MON, the CMAS rule specifies mass emission thresholds above 
which more stringent control of batch process vents is required. 
Petitioners state that it can be difficult under the CMAS rule to 
determine what constitutes a family of materials. Petitioners believe 
that the term ``family of materials'' effectively expands the scope of 
a CMPU to include equipment that is not part of a process that uses or 
produces Table 1 HAP. Petitioners contend that there is no policy 
justification for applying the CMAS rule this broadly. Therefore, 
Petitioners request that the EPA interpret the ``family of materials'' 
term in such a way as to avoid regulating equipment that is not used to 
process a Table 1 HAP. Alternatively, Petitioners suggest that the EPA 
propose eliminating the phrase ``or a family of materials'' from the 
rule.
    The definition of ``family of materials'' in the MON, and 
referenced in 40 CFR 63.11502 of the CMAS final rule, is as follows:

    Family of materials means a grouping of materials with the same 
basic composition or the same basic end use or functionality 
produced using the same basic feedstocks with essentially identical 
HAP emission profiles (primary constituent and relative magnitude on 
a pound per pound basis) and manufacturing equipment configuration. 
Examples of families of materials include multiple grades of the 
same product or different variations of a product (e.g., blue, black 
and red resins).
    As in the MON, the intent of the family of materials concept in 40 
CFR part 63, subpart VVVVVV is to ensure that sources will not be able 
to improperly avoid installation of add-on controls for batch process 
vent emissions by creating separate CMPU for production of essentially 
the same products (i.e., products produced from the same basic raw 
materials, with essentially identical HAP emissions, and using the same 
configuration of manufacturing equipment). For example, a series of 
polymer products that differ only in molecular weight or the type of 
non-HAP additive are considered a family of materials when the same 
primary raw materials are used, the same types of HAP are emitted and 
the same configuration of production equipment is used. However, 
because the definition of family of materials in the final rule uses 
the term ``essentially'' identical HAP emission profiles, a family of 
materials potentially could include some products whose production does 
not involve Table 1 HAP. Therefore, to clarify the requirements, we are 
proposing to revise the definition of family of materials to state that 
only those products whose production involves emission of the same 
Table 1 HAP are to be considered part of a family of materials.
    We also want to clarify the family of materials concept as it 
relates to production of isolated intermediates. A chemical 
manufacturing process is defined, in part, as ``all equipment which 
collectively functions to produce a product or isolated intermediate.'' 
An isolated intermediate is defined, in part, as ``a product of a 
process that is stored before subsequent processing.'' (As discussed in 
section VII of this preamble, we are proposing to add a definition of 
``isolated intermediate'' that is consistent with the definition in the 
MON.) Even if an isolated intermediate and final product are produced 
using the same manufacturing equipment configuration and have the same 
Table 1 HAP emissions, they generally cannot be part of a family of 
materials because the definition specifies production of all products 
in the family must involve the same basic feedstocks. This condition 
would not be met if an isolated intermediate is used as a feedstock in 
later production of a final product. Furthermore, the definition of 
family of materials specified that all products in the family must have 
the same basic composition, end use, or functionality. This condition 
also would not be met in a situation where the isolated intermediate is 
transformed in the process to produce the final product.
    We are requesting comment on all aspects of the family of materials 
concept, including the proposed change. We are particularly interested 
in descriptions of situations where someone thinks it would apply, but 
should not, and we request suggestions for additional changes that 
would make it easier to understand, apply and enforce. We are not, 
however, accepting comments on the use of the CMPU as the basis for 
determining applicability of the CMAS final rule.

V. Requirements During Periods of Startup, Shutdown and Malfunction 
(SSM)

    During the comment period of the proposed rule, the United States 
Court of Appeals for the District of Columbia Circuit vacated two 
provisions in the EPA's CAA section 112 regulations governing the 
emissions of HAP during periods of startup, shutdown and malfunction 
(SSM). Sierra Club v. EPA, 551 F.3d 1019 (D.C. Cir. 2008), cert. 
denied, 130 S. Ct. 1735 (U.S. 2010). Specifically, the Court vacated 
the SSM exemption contained in 40 CFR 63.6(f)(1) and 40 CFR 63.6(h)(1), 
that are part of a regulation, commonly referred to as the ``General 
Provisions Rule,'' that the EPA promulgated under section 112 of the 
CAA. When incorporated into CAA section 112(d) regulations for specific 
source categories, the exemption in these two provisions exempts 
sources from the requirement to comply with the otherwise applicable 
CAA section 112(d) emission standard during periods of SSM.
    The proposed CMAS rule contained references to the vacated 
provisions. Because the provisions were vacated, we removed the 
references in the final rule, and, in their place, we included 
alternative standards for startup and shutdown periods for continuous 
process vents. Table 3 to 40 CFR part 63, subpart VVVVVV. For batch 
process vents, we determined that startup and shutdown periods were 
already accounted for in the existing standard, and we determined that 
the remaining equipment did not have periods of startup and shutdown. 
74 FR 56013. We declined to establish a different standard for 
malfunctions, as suggested by commenters. 74 FR 56033.
    Further, as explained in the preamble to the final rule (74 FR 
56033), periods of startup, normal operations and shutdown are all 
predictable and

[[Page 4531]]

routine aspects of a source's operations. However, by contrast, 
malfunction is defined as 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 * 
* *'' (40 CFR 63.2). Nothing in CAA section 112(d) or in case law 
requires that the EPA anticipate and account for the innumerable types 
of potential malfunction events in setting emission standards. See 
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.''). 
Further, it is reasonable to interpret CAA section 112(d) as not 
requiring the EPA to account for malfunctions in setting emissions 
standards.
    We believe it would be impracticable to take malfunctions into 
account in setting CAA section 112(d) standards for chemical 
manufacturing area sources. As noted above, by definition, malfunctions 
are sudden and unexpected events, and it would be difficult to set a 
standard that takes into account the myriad different types of 
malfunctions that can occur across all sources in the categories. 
Moreover, malfunctions can vary in frequency, degree and duration, 
further complicating standard setting. See, e.g., Sierra Club v. EPA, 
167 F.3d 658, 662 (D.C. Cir. 1999) (the EPA typically has