Document ID: EPA-HQ-OAR-2010-0600-0001
Agency: epa
Document Type: Proposed Rule
Title: National Emission Standards for Hazardous Air Pollutant Emissions: Hard and Decorative Chromium Electroplating and Chromium Anodizing Tanks; Group I Polymers and Resins, Marine Tank Vessel Loading Operations: Pharmaceuticals Production; The Printing and Publishing Industry; and Steel Pickling - HCI Process Facilities and Hydrochloric Acid Regeneration Plants
Posted Date: 2010-10-21T04:00Z

[Federal Register: October 21, 2010 (Volume 75, Number 203)]
[Proposed Rules]               
[Page 65067-65149]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr21oc10-24]                         

[[Page 65067]]

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Part II

Environmental Protection Agency

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40 CFR Part 63

National Emission Standards for Hazardous Air Pollutant Emissions: Hard 
and Decorative Chromium Electroplating and Chromium Anodizing Tanks; 
Group I Polymers and Resins; Marine Tank Vessel Loading Operations; 
Pharmaceuticals Production; The Printing and Publishing Industry; and 
Steel Pickling--HCl Process Facilities and Hydrochloric Acid 
Regeneration Plants; Proposed Rule

[[Page 65068]]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 63

[EPA-HQ-OAR-2010-0600; FRL-9203-7]
RIN 2060-AO91

 
National Emission Standards for Hazardous Air Pollutant 
Emissions: Hard and Decorative Chromium Electroplating and Chromium 
Anodizing Tanks; Group I Polymers and Resins; Marine Tank Vessel 
Loading Operations; Pharmaceuticals Production; The Printing and 
Publishing Industry; and Steel Pickling--HCl Process Facilities and 
Hydrochloric Acid Regeneration Plants

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule; and supplemental notice of proposed rulemaking.

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SUMMARY: This action proposes how EPA will address the residual risk 
and technology reviews conducted for two national emission standards 
for hazardous air pollutants (NESHAP), and this action is a 
supplemental notice of proposed rulemaking for an October 2008 action 
that proposed how EPA would address the residual risk and technology 
reviews for four NESHAP. The six NESHAP include 16 source categories, 
12 of which are the subject of residual risk and technology reviews in 
this package. This action proposes to modify the existing emissions 
standards for eight source categories in three of the six NESHAP to 
address certain emission sources not currently regulated under these 
standards. It also proposes for all six NESHAP to address provisions 
related to emissions during periods of startup, shutdown, and 
malfunction. Finally, this action proposes changes to two of the six 
NESHAP to correct editorial errors, make clarifications, or address 
issues with implementation or determining compliance.

DATES: Comments. Comments must be received on or before December 6, 
2010. Under the Paperwork Reduction Act, comments on the information 
collection provisions are best assured of having full effect if the 
Office of Management and Budget (OMB) receives a copy of your comments 
on or before November 22, 2010.
    Public Hearing. We will hold a public hearing on November 5, 2010. 
Persons requesting to speak at the public hearing must contact EPA by 
November 1, 2010.

ADDRESSES: Comments. Submit your comments, identified by Docket ID No. 
EPA-HQ-OAR-2010-0600, by one of the following methods:
     http://www.regulations.gov: Follow the on-line 
instructions for submitting comments.
     E-mail: a-and-r-docket@epa.gov. Attention Docket ID No. 
EPA-HQ-OAR-2010-0600.
     Fax: (202) 566-9744. Attention Docket ID No. EPA-HQ-OAR-
2010-0600.
     Mail: U.S. Postal Service, send comments to: EPA Docket 
Center, EPA West (Air Docket), Attention Docket ID No. EPA-HQ-OAR-2010-
0600, U.S. Environmental Protection Agency, Mailcode: 2822T, 1200 
Pennsylvania Ave., NW., Washington, DC 20460. Please include a total of 
two copies. In addition, please mail a copy of your comments on the 
information collection provisions to the Office of Information and 
Regulatory Affairs, Office of Management and Budget (OMB), Attn: Desk 
Officer for EPA, 725 17th Street, NW., Washington, DC 20503.
     Hand Delivery: U.S. Environmental Protection Agency, EPA 
West (Air Docket), Room 3334, 1301 Constitution Ave., NW., Washington, 
DC 20004. Attention Docket ID No. EPA-HQ-OAR-2010-0600. 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-
2010-0600. EPA's policy is that all comments received will be included 
in the public docket without change and may be made available online at 
http://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 http://
www.regulations.gov or e-mail. The http://www.regulations.gov Web site 
is an ``anonymous access'' system, which means EPA will not know your 
identity or contact information unless you provide it in the body of 
your comment. If you send an e-mail comment directly to EPA without 
going through http://www.regulations.gov, your e-mail 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, EPA recommends that you include your name 
and other contact information in the body of your comment and with any 
disk or CD-ROM you submit. If EPA cannot read your comment due to 
technical difficulties and cannot contact you for clarification, EPA 
may not be able to consider your comment. Electronic files should avoid 
the use of special characters, any form of encryption, and be free of 
any defects or viruses. For additional information about EPA's public 
docket, visit the EPA Docket Center homepage at http://www.epa.gov/
epahome/dockets.htm.
    Docket. The EPA has established a docket for this rulemaking under 
Docket ID No. EPA-HQ-OAR-2010-0600. All documents in the docket are 
listed in the http://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, is not placed on the Internet 
and will be publicly available only in hard copy. Publicly available 
docket materials are available either electronically in http://
www.regulations.gov or in hard copy at the EPA Docket Center, EPA West, 
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 EPA 
Docket Center is (202) 566-1742.
    Public Hearing. We will hold a public hearing concerning this 
proposed rule on November 5, 2010, from 9 a.m. to 7 p.m. Persons 
interested in presenting oral testimony at the hearing should contact 
Ms. Mary Tom Kissell, Sector Policies and Programs Division (E143-01), 
Office of Air Quality Planning and Standards, U.S. Environmental 
Protection Agency, Research Triangle Park, NC 27711, telephone number, 
(919) 541-4516, by November 1, 2010. The public hearing will be held at 
the U.S. Environmental Protection Agency--Research Triangle Park 
Campus, 109 T.W. Alexander Drive, Research Triangle Park, NC 27709. If 
no one requests to speak at the public hearing by November 1, 2010, 
then the public hearing will be cancelled and a notification of 
cancellation posted on the following Web site: http://www.epa.gov/ttn/
oarpg/t3main.html.

FOR FURTHER INFORMATION CONTACT: For questions about this proposed 
action, contact Ms. Mary Tom Kissell, Sector Policies and Programs 
Division (E143-01), Office of Air Quality Planning and Standards, U.S. 
Environmental Protection Agency, Research Triangle Park, NC 27711, 
telephone (919) 541-

[[Page 65069]]

4516; fax number: (919) 541-0246; and e-mail address: 
kissell.mary@epa.gov. For specific information regarding the risk 
modeling methodology, contact Ms. Elaine Manning, Health and 
Environmental Impacts Division (C539-02), Office of Air Quality 
Planning and Standards, U.S. Environmental Protection Agency, Research 
Triangle Park, NC 27711; telephone number: (919) 541-5499; fax number: 
(919) 541-0840; and e-mail address: manning.elaine@epa.gov. For 
information about the applicability of these six NESHAP to a particular 
entity, contact the appropriate person listed in Table 1 to this 
preamble.

SUPPLEMENTARY INFORMATION:

                                     Table 1--List of EPA Contacts for the NESHAP Addressed in This Proposed Action
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               NESHAP for:                                   OECA contact \1\                                        OAQPS contact \2\
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Hard and Decorative Chromium              Scott Throwe, (202) 564-7013, throwe.scott@epa.gov....  Phil Mulrine, (919) 541-5289, mulrine.phil@epa.gov.
 Electroplating and Chromium Anodizing
 Tanks.
Group I Polymers and Resins Production..  Scott Throwe, (202) 564-7013, throwe.scott@epa.gov....  Randy McDonald, (919) 541-5402,
                                                                                                   mcdonald.randy@epa.gov.
Marine Vessel Loading Operations........  Maria Malave, (202) 564-7027, malave.maria@epa.gov....  Steve Shedd, (919) 541-5397, shedd.steve@epa.gov.
Pharmaceuticals Production..............  Marcia Mia, (202) 564-7042, mia.marcia@epa.gov........  Randy McDonald, (919) 541-5402,
                                                                                                   mcdonald.randy@epa.gov.
Printing and Publishing Industry........  Len Lazarus, (202) 564-6369, lazarus.leonard@epa.gov..  David Salman, (919) 541-0859, salman.dave@epa.gov.
Steel Pickling--HCl Process Facilities    Maria Malave, (202) 564-7027, malave.maria@epa.gov....  Phil Mulrine, (919) 541-5289, mulrine.phil@epa.gov.
 and Hydrochloric Acid Regeneration
 Plants.
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\1\ OECA stands for EPA's Office of Enforcement and Compliance Assurance.
\2\ OAQPS stands for EPA's Office of Air Quality Planning and Standards.

I. Preamble Acronyms and Abbreviations

    Several acronyms and terms used to describe industrial processes, 
data inventories, and risk modeling are included in this preamble. 
While this may not be an exhaustive list, to ease the reading of this 
preamble and for reference purposes, the following terms and acronyms 
are defined here:

AERMOD--The air dispersion model used by the HEM-3 model
AEGL--Acute Exposure Guideline Levels
ANPRM--Advance Notice of Proposed Rulemaking
ASTM--An international standards organization that develops and 
publishes voluntary consensus technical standards
ATCM--Airborne Toxics Control Measure
ATSDR--Agency for Toxic Substances and Disease Registry
BACT--Best Available Control Technology
bbl/yr--Barrels per Year
BID--Background Information Document
CalEPA--California Environmental Protection Agency
CARB--California Air Resources Board
CAA--Clean Air Act
CBI--Confidential Business Information
CEEL--Community Emergency Exposure Levels
CIIT--Chemical Industry Institute of Toxicology
CFR--Code of Federal Regulations
CMP--Composite Mesh Pad
CO--Carbon Monoxide
CO2--Carbon Dioxide
D/F--Dioxin/Furan
EED--Emission Elimination Device
EPA--Environmental Protection Agency
EPS--Eco Pickled Surface
ERPG--Emergency Response Planning Guidelines
HAP--Hazardous Air Pollutants
HCl--Hydrochloric Acid
HI--Hazard Index
HEM-3--Human Exposure Model version 3
HEPA--High Efficiency Particulate Air
HON--Hazardous Organic National Emissions Standards for Hazardous 
Air Pollutants
HQ--Hazard Quotient
ICR--Information Collection Request
IRIS--Integrated Risk Information System
Km--Kilometer
LAER--Lowest Achievable Emission Rate
MACT--Maximum Achievable Control Technology
MACT Code--A code within the NEI used to identify processes included 
in a source category
mg/dscm--Milligrams per Dry Standard Cubic Meter
MIR--Maximum Individual Risk
MTVLO--Marine Tank Vessel Loading Operations
NAC/AEGL Committee--National Advisory Committee for Acute Exposure 
Guideline Levels for Hazardous Substances
NAICS--North American Industry Classification System
NAS--National Academy of Sciences
NATA--National Air Toxics Assessment
NESHAP--National Emissions Standards for Hazardous Air Pollutants
NEI--National Emissions Inventory
NOX--Nitrogen Oxide
NRC--National Research Council
NSR--New Source Review
NTTAA--National Technology Transfer and Advancement Act
OECA--Office of Enforcement and Compliance Assurance
OLD--Organic Liquids Distribution
OMB--Office of Management and Budget
PB-HAP--Hazardous air pollutants known to be persistent and bio-
accumulative in the environment
PFC--Perfluorinated Chemical
PFOS--Perfluorooctyl Sulfonate
PM--Particulate Matter
POM--Polycyclic Organic Matter
RACT--Reasonably Available Control Technology
RBLC--RACT/BACT/LAER Clearinghouse
REL--CalEPA Chronic Reference Exposure Level
RFA--Regulatory Flexibility Act
RfC--Reference Concentration
RfD--Reference Dose
RTR--Residual Risk and Technology Review
SAB--Science Advisory Board
SCC--Source Classification Codes
SCS--Smooth Clean Surface
SF3--2000 Census of Population and Housing Summary File 3
SO2--Sulfur Dioxide
SOP--Standard Operating Procedures
SSM--Startup, Shutdown, and Malfunction
TOSHI--Target Organ-Specific Hazard Index
TPY--Tons Per Year
TRIM--Total Risk Integrated Modeling System
TTN--Technology Transfer Network
UF--Uncertainty Factor
UMRA--Unfunded Mandates Reform Act
URE--Unit Risk Estimate
VOC--Volatile Organic Compounds
WAFS--Wetting Agent/Fume Suppressant
WCSC--Waterborne Commerce Statistics Center
WWW--Worldwide Web

II. General Information

A. Does this action apply to me?

    The regulated industrial source categories that are the subject of 
this proposal are listed in Table 2 to this preamble. Table 2 is not 
intended to be exhaustive, but rather provides a guide for readers 
regarding entities likely to be affected by the proposed action for the 
source categories listed. These standards, and any changes considered 
in this rulemaking, would be directly applicable to sources as a 
Federal program. Thus, Federal, State, local, and tribal government 
entities are not affected by this proposed action. The

[[Page 65070]]

regulated categories affected by this proposed action include:

                Table 2--NESHAP and Industrial Source Categories Affected by This Proposed Action
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                           NESHAP and source category                             NAICS code \1\   MACT code \2\
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Chromium Electroplating.......................  Chromium Anodizing Tanks........          332813            1607
                                                Decorative Chromium                       332813            1610
                                                 Electroplating.
                                                Hard Chromium Electroplating....          332813            1615
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Group I Polymers and Resins...................  Butyl Rubber Production.........          325212            1307
                                                Epichlorohydrin Elastomers                325212            1311
                                                 Production.
                                                Ethylene Propylene Rubber                 325212            1313
                                                 Production.
                                                Hypalon\TM\ Production \3\......          325212            1315
                                                Neoprene Production.............          325212            1320
                                                Nitrile Butadiene Rubber                  325212            1321
                                                 Production.
                                                Polybutadiene Rubber Production.          325212            1325
                                                Polysulfide Rubber Production             325212            1332
                                                 \3\.
                                                Styrene Butadiene Rubber and              325212            1339
                                                 Latex Production.
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Marine Vessel Loading Operations................................................            4883            0603
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Pharmaceuticals Production......................................................            3254            1201
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Printing and Publishing Industry................................................           32311            0714
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Steel Pickling--HCl Process Facilities and Hydrochloric Acid Regeneration Plants      3311, 3312            0310
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\1\ North American Industry Classification System.
\2\ Maximum Achievable Control Technology.
\3\ There are no longer any operating facilities in either the Hypalon\TM\ or Polysulfide Rubber source
  categories. Therefore, this proposal does not address these source categories.

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 proposal will also be available on the World Wide Web (WWW) 
through the Technology Transfer Network (TTN). Following signature by 
the EPA Administrator, a copy of this proposed action will be posted on 
the TTN's policy and guidance page for newly proposed or promulgated 
rules at the following address: http://www.epa.gov/ttn/atw/rrisk/
rtrpg.html. The TTN provides information and technology exchange in 
various areas of air pollution control.
    Additional information is available on the residual risk and 
technology review (RTR) Web page at http://www.epa.gov/ttn/atw/rrisk/
rtrpg.html. This information includes source category descriptions and 
detailed emissions and other data that were used as inputs to the risk 
assessments.

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

    Submitting CBI. Do not submit information containing CBI to EPA 
through http://www.regulations.gov or e-mail. Clearly mark the part or 
all of the information that you claim to be CBI. For CBI information on 
a disk or CD-ROM that you mail to 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 CD-ROM or disk that does not contain CBI, mark the outside 
of the disk or CD-ROM clearly that it does not contain CBI. Information 
not marked as CBI will be included in the public docket and EPA's 
electronic public docket without prior notice. Information marked as 
CBI will not be disclosed except in accordance with procedures set 
forth in 40 CFR part 2. Send or deliver information identified as CBI 
only to the following address: Roberto Morales, OAQPS Document Control 
Officer (C404-02), Office of Air Quality Planning and Standards, U.S. 
Environmental Protection Agency, Research Triangle Park, NC 27711, 
Attention Docket ID No. EPA-HQ-OAR-2010-0600.

D. How is this document organized?

    The information in this preamble is organized as follows:

I. Preamble Acronyms and Abbreviations
II. General Information
    A. Does this action apply to me?
    B. Where can I get a copy of this document and other related 
information?
    C. What should I consider as I prepare my comments for EPA?
    D. How is this document organized?
III. Background
    A. What is the statutory authority for this action?
    B. How did we consider the risk results in making decisions for 
this proposal?
    C. What other actions are we addressing in this proposal?
    D. What specific RTR actions have previously been taken for 
these source categories?
IV. Analyses Performed
    A. How did we estimate risk posed by the source categories?
    B. How did we perform the technology review?
    C. How did we perform the analyses for the other actions being 
proposed?
V. Analyses Results and Proposed Decisions
    A. What are the results and proposed decisions for the Chromium 
Electroplating source categories?
    B. What are the results and proposed decisions for the Group I 
Polymers and Resins Production source categories?
    C. What are the results and proposed decisions for Marine Tank 
Vessel Loading Operations source category?
    D. What are the results and proposed decisions for the 
Pharmaceuticals Production source category?
    E. What are the results and proposed decisions for the Printing 
and Publishing Industry source category?
    F. What are the results and proposed decisions for Steel 
Pickling-HCl Process

[[Page 65071]]

Facilities and Hydrochloric Acid Regeneration Plants source 
category?
VI. Summary of Proposed Actions
    A. What actions are we proposing as a result of the technology 
reviews?
    B. What actions are we proposing as a result of the residual 
risk reviews?
    C. What other actions are we proposing?
VII. Request for Comments
VIII. Submitting Data Corrections
IX. Statutory and Executive Order Reviews
    A. Executive Order 12866: Regulatory Planning and 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

III. Background

A. What is the statutory authority for this action?

    Section 112 of the Clean Air Act (CAA) establishes a two-stage 
regulatory process to address emissions of hazardous air pollutants 
(HAP) from stationary sources. In the first stage, after EPA has 
identified categories of sources emitting one or more of the HAP listed 
in section 112(b) of the CAA, section 112(d) of the CAA calls for us to 
promulgate 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 of a single HAP or 25 TPY or more of any 
combination of HAP. For major sources, these technology-based standards 
must reflect the maximum degree of emission reductions of HAP 
achievable (after considering cost, energy requirements, and non-air 
quality health and environmental impacts) and are commonly referred to 
as maximum achievable control technology (MACT) standards.
    MACT standards are to reflect application of measures, processes, 
methods, systems, or techniques, including, but not limited to, 
measures which, (A) reduce the volume of or eliminate pollutants 
through process changes, substitution of materials or other 
modifications, (B) enclose systems or processes to eliminate emissions, 
(C) capture or treat pollutants when released from a process, stack, 
storage, or fugitive emissions point, (D) are design, equipment, work 
practice, or operational standards (including requirements for operator 
training or certification), or (E) are a combination of the above. CAA 
section 112(d)(2)(A)-(E). The MACT standard may take the form of a 
design, equipment, work practice, or operational standard where EPA 
first determines either that (A) a pollutant cannot be emitted through 
a conveyance designed and constructed to emit or capture the pollutant, 
or that any requirement for or use of such a conveyance would be 
inconsistent with law, or (B) the application of measurement 
methodology to a particular class of sources is not practicable due to 
technological and economic limitations. CAA sections 112(h)(1)-(2).
    The MACT ``floor'' is the minimum control level allowed for MACT 
standards promulgated under CAA section 112(d)(3), and may not be based 
on cost considerations. For new sources, the MACT floor cannot be less 
stringent than the emission control that is achieved in practice by the 
best-controlled similar source. The MACT floors 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. 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.
    The EPA is then required to review these technology-based standards 
and to revise them ``as necessary (taking into account developments in 
practices, processes, and control technologies)'' no less frequently 
than every 8 years, under CAA section 112(d)(6). In conducting this 
review, EPA is not obliged to completely recalculate the prior MACT 
determination. NRDC v. EPA, 529 F.3d 1077, 1084 (District of Columbia 
Circuit, 2008).
    The second stage in standard-setting focuses on reducing any 
remaining ``residual'' risk according to CAA section 112(f). This 
provision requires, first, that EPA prepare a Report to Congress 
discussing (among other things) methods of calculating risk posed (or 
potentially posed) by sources after implementation of the MACT 
standards, the public health significance of those risks, the means and 
costs of controlling them, the actual health effects to persons in 
proximity of emitting sources, and the recommendations regarding 
legislation of such remaining risk. EPA prepared and submitted this 
report (Residual Risk Report to Congress, EPA-453/R-99-001) in March 
1999. Congress did not act in response to the report, thereby 
triggering EPA's obligation under CAA section 112(f)(2) to analyze and 
address residual risk.
    CAA section 112(f)(2) requires us to determine for source 
categories subject to certain MACT standards, whether the emissions 
standards provide an ample margin of safety to protect public health. 
If the MACT standards for HAP ``classified as a known, probable, or 
possible human carcinogen do not reduce lifetime excess cancer risks to 
the individual most exposed to emissions from a source in the category 
or subcategory to less than 1-in-1 million,'' EPA must promulgate 
residual risk standards for the source category (or subcategory) as 
necessary to provide an ample margin of safety to protect public 
health. In doing so, EPA may adopt standards equal to existing MACT 
standards if EPA determines that the existing standards are 
sufficiently protective. NRDC v. EPA, 529 F.3d 1077, 1083 (District of 
Columbia Circuit, 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.'') EPA must also adopt more stringent standards, if 
necessary, to prevent an adverse environmental effect,\1\ but must 
consider cost, energy, safety, and other relevant factors in doing so.
---------------------------------------------------------------------------

    \1\ ``Adverse environmental effect'' is defined in CAA section 
112(a)(7) as any significant and widespread adverse effect, which 
may be reasonably anticipated to wildlife, aquatic life, or natural 
resources, including adverse impacts on populations of endangered or 
threatened species or significant degradation of environmental 
qualities over broad areas.
---------------------------------------------------------------------------

    Section 112(f)(2) of the CAA expressly preserves our use of a two-
step process for developing standards to address any residual risk and 
our interpretation of ``ample margin of safety'' developed in the 
National Emission Standards for Hazardous Air Pollutants: Benzene 
Emissions from Maleic Anhydride Plants, Ethylbenzene/Styrene Plants, 
Benzene Storage Vessels, Benzene Equipment Leaks, and Coke By-Product 
Recovery Plants (Benzene NESHAP) (54 FR 38044, September 14, 1989). The

[[Page 65072]]

first step in this process is the determination of acceptable risk. The 
second step provides for an ample margin of safety to protect public 
health, which is the level at which the standards are set (unless a 
more stringent standard is required to prevent, taking into 
consideration costs, energy, safety, and other relevant factors, an 
adverse environmental effect).
    The terms ``individual most exposed,'' ``acceptable level,'' and 
``ample margin of safety'' are not specifically defined in the CAA. 
However, CAA section 112(f)(2)(B) preserves the interpretation set out 
in the Benzene NESHAP, and the United States Court of Appeals for the 
District of Columbia Circuit in NRDC v. EPA, 529 F.3d 1077, concluded 
that EPA's interpretation of section 112(f)(2) is a reasonable one. See 
NRDC v. EPA, 529 F.3d at 1083 (District of Columbia Circuit, 
``[S]ubsection 112(f)(2)(B) expressly incorporates EPA's interpretation 
of the Clean Air Act from the Benzene standard, complete with a 
citation to the Federal Register''). (District of Columbia Circuit 
2008). See also, A Legislative History of the Clean Air Act Amendments 
of 1990, volume 1, p. 877 (Senate debate on Conference Report). We 
notified Congress in the Residual Risk Report to Congress that we 
intended to use the Benzene NESHAP approach in making CAA section 
112(f) residual risk determinations (EPA-453/R-99-001, p. ES-11).
    In the Benzene NESHAP, we stated as an overall objective:

     * * * in protecting public health with an ample margin of 
safety, we strive to provide maximum feasible protection against 
risks to health from hazardous air pollutants by (1) protecting the 
greatest number of persons possible to an individual lifetime risk 
level no higher than approximately 1-in-1 million; and (2) limiting 
to no higher than approximately 1-in-10 thousand [i.e., 100-in-1 
million] the estimated risk that a person living near a facility 
would have if he or she were exposed to the maximum pollutant 
concentrations for 70 years.

    The Agency also stated that, ``The EPA also considers incidence 
(the number of persons estimated to suffer cancer or other serious 
health effects as a result of exposure to a pollutant) to be an 
important measure of the health risk to the exposed population. 
Incidence measures the extent of health risk to the exposed population 
as a whole, by providing an estimate of the occurrence of cancer or 
other serious health effects in the exposed population.'' The Agency 
went on to conclude that ``estimated incidence would be weighed along 
with other health risk information in judging acceptability.'' As 
explained more fully in our Residual Risk Report to Congress, EPA does 
not define ``rigid line[s] of acceptability,'' but considers rather 
broad objectives to be weighed with a series of other health measures 
and factors (EPA-453/R-99-001, p. ES-11). The determination of what 
represents an ``acceptable'' risk is based on a judgment of ``what 
risks are acceptable in the world in which we live'' (Residual Risk 
Report to Congress, p. 178, quoting the Vinyl Chloride decision at 824 
F.2d 1165) recognizing that our world is not risk-free.
    In the Benzene NESHAP, we stated that ``EPA will generally presume 
that if the risk to [the maximum exposed] individual is no higher than 
approximately 1-in-10 thousand, that risk level is considered 
acceptable.'' 54 FR 38045. We discussed the maximum individual lifetime 
cancer risk as being ``the estimated risk that a person living near a 
plant would have if he or she were exposed to the maximum pollutant 
concentrations for 70 years.'' Id. We explained that this measure of 
risk ``is an estimate of the upper bound of risk based on conservative 
assumptions, such as continuous exposure for 24 hours per day for 70 
years.'' Id. We acknowledge that maximum individual lifetime cancer 
risk ``does not necessarily reflect the true risk, but displays a 
conservative risk level which is an upper-bound that is unlikely to be 
exceeded.'' Id.
    Understanding that there are both benefits and limitations to using 
maximum individual lifetime cancer risk as a metric for determining 
acceptability, we acknowledged in the 1989 Benzene NESHAP that 
``consideration of maximum individual risk * * * must take into account 
the strengths and weaknesses of this measure of risk.'' Id. 
Consequently, the presumptive risk level of 100-in-1 million (1-in-10 
thousand) provides a benchmark for judging the acceptability of maximum 
individual lifetime cancer risk, but does not constitute a rigid line 
for making that determination.
    The Agency also explained in the 1989 Benzene NESHAP the following: 
``In establishing a presumption for MIR [maximum individual cancer 
risk], rather than a rigid line for acceptability, the Agency intends 
to weigh it with a series of other health measures and factors. These 
include the overall incidence of cancer or other serious health effects 
within the exposed population, the numbers of persons exposed within 
each individual lifetime risk range and associated incidence within, 
typically, a 50-kilometer (km) exposure radius around facilities, the 
science policy assumptions and estimation uncertainties associated with 
the risk measures, weight of the scientific evidence for human health 
effects, other quantified or unquantified health effects, effects due 
to co-location of facilities, and co-emission of pollutants.'' Id.
    In some cases, these health measures and factors taken together may 
provide a more realistic description of the magnitude of risk in the 
exposed population than that provided by maximum individual lifetime 
cancer risk alone. As explained in the Benzene NESHAP, ``[e]ven though 
the risks judged ``acceptable'' by EPA in the first step of the Vinyl 
Chloride inquiry are already low, the second step of the inquiry, 
determining an ``ample margin of safety,'' again includes consideration 
of all of the health factors, and whether to reduce the risks even 
further.'' In the ample margin of safety decision process, the Agency 
again considers all of the health risks and other health information 
considered in the first step. Beyond that information, additional 
factors relating to the appropriate level of control will also be 
considered, including costs and economic impacts of controls, 
technological feasibility, uncertainties, and any other relevant 
factors. Considering all of these factors, the Agency will establish 
the standard at a level that provides an ample margin of safety to 
protect the public health, as required by CAA section 112(f). 54 FR 
38046.

B. How did we consider the risk results in making decisions for this 
proposal?

    As discussed in section III.A. of this preamble, we apply a two-
step process for developing standards to address residual risk. In the 
first step, EPA determines if risks are acceptable. This determination 
``considers all health information, including risk estimation 
uncertainty, and includes a presumptive limit on maximum individual 
lifetime [cancer] risk (MIR) \2\ of approximately 1-in-10 thousand 
[i.e., 100-in-1 million].'' 54 FR 38045. In the second step of the 
process, EPA sets the standard at a level that provides an ample margin 
of safety ``in consideration of all health information, including the 
number of persons at risk levels higher than approximately 1-in-1 
million, as well as other relevant factors, including costs and 
economic impacts, technological

[[Page 65073]]

feasibility, and other factors relevant to each particular decision.'' 
Id.
---------------------------------------------------------------------------

    \2\ Although defined as ``maximum individual risk,'' MIR refers 
only to cancer risk. MIR, one metric for assessing cancer risk, is 
the estimated risk were an individual exposed to the maximum level 
of a pollutant for a lifetime.
---------------------------------------------------------------------------

    In past residual risk determinations, EPA presented a number of 
human health risk metrics associated with emissions from the category 
under review, including: The MIR; the numbers of persons in various 
risk ranges; cancer incidence; the maximum non-cancer hazard index 
(HI); and the maximum acute non-cancer hazard. In estimating risks, EPA 
considered source categories under review that are located near each 
other and that affect the same population. EPA provided estimates of 
the expected difference in actual emissions from the source category 
under review and emissions allowed pursuant to the source category MACT 
standard. EPA also discussed and considered risk estimation 
uncertainties. EPA is providing this same type of information in 
support of these actions.
    However, in contrast to past determinations, this notice presents 
and considers additional measures of health information to support our 
decision-making. These are discussed in more detail in later sections 
of this notice, and include:
     Estimates of ``total facility'' cancer and non-cancer risk 
(risk from all HAP emissions from the facility at which the source 
category is located).
     Demographic analyses (analyses of the distributions of 
HAP-related cancer risks and non-cancer risks, across different social, 
demographic, and economic groups within the populations living near the 
facilities where these source categories are located).
     Additional estimates of the risks associated with 
emissions allowed by the MACT standard.
    The Agency is considering all of this available health information 
to inform our determinations of risk acceptability and ample margin of 
safety under CAA section 112(f). Specifically, as explained in the 
Benzene NESHAP, ``the first step judgment on acceptability cannot be 
reduced to any single factor,'' and, thus, ``[t]he Administrator 
believes that the acceptability of risk under section 112 is best 
judged on the basis of a broad set of health risk measures and 
information.'' 54 FR 38044 and 38046, September 14, 1989. Similarly, 
with regard to making the ample margin of safety determination, the 
Benzene NESHAP state that ``[I]n the ample margin decision, the Agency 
again considers all of the health risk and other health information 
considered in the first step. Beyond that information, additional 
factors relating to the appropriate level of control will also be 
considered, including cost and economic impacts of controls, 
technological feasibility, uncertainties, and any other relevant 
factors.'' Id.
    The Agency acknowledges that the Benzene NESHAP provide flexibility 
regarding what factors the EPA might consider in making our 
determinations and how they might be weighed for each source category. 
In responding to comment on our policy under the Benzene NESHAP, EPA 
explained that: ``The policy chosen by the Administrator permits 
consideration of multiple measures of health risk. Not only can the MIR 
figure be considered, but also incidence, the presence of non-cancer 
health effects, and the uncertainties of the risk estimates. In this 
way, the effect on the most exposed individuals can be reviewed as well 
as the impact on the general public. These factors can then be weighed 
in each individual case. This approach complies with the Vinyl Chloride 
mandate that the Administrator ascertain an acceptable level of risk to 
the public by employing [her] expertise to assess available data. It 
also complies with the Congressional intent behind the CAA, which did 
not exclude the use of any particular measure of public health risk 
from the EPA's consideration with respect to CAA section 112 
regulations, and, thereby, implicitly permits consideration of any and 
all measures of health risk which the Administrator, in [her] judgment, 
believes are appropriate to determining what will `protect the public 
health.' '' 54 FR 38057.
    For example, the level of the MIR is only one factor to be weighed 
in determining acceptability of risks. The Benzene NESHAP explain ``an 
MIR of approximately 1-in-10 thousand should ordinarily be the upper 
end of the range of acceptability. As risks increase above this 
benchmark, they become presumptively less acceptable under CAA section 
112, and would be weighed with the other health risk measures and 
information in making an overall judgment on acceptability. Or, the 
Agency may find, in a particular case, that a risk that includes MIR 
less than the presumptively acceptable level is unacceptable in the 
light of other health risk factors.'' Id. at 38045. Similarly, with 
regard to the ample margin of safety analysis, the Benzene NESHAP state 
that: ``* * * EPA believes the relative weight of the many factors that 
can be considered in selecting an ample margin of safety can only be 
determined for each specific source category. This occurs mainly 
because technological and economic factors (along with the health-
related factors) vary from source category to source category.'' Id. at 
38061.
    EPA wishes to point out that certain health information has not 
been considered in these decisions. In assessing risks to populations 
in the vicinity of the facilities in each category, we present 
estimates of risk associated with HAP emissions from the source 
category alone (source category risk estimates) and HAP emissions from 
the entire facilities at which the covered source categories are 
located (facility-wide risk estimates). We have not presented estimates 
of total HAP inhalation risks from all sources in the vicinity of the 
covered sources (i.e., the sum of risks from ambient levels, emissions 
from the source category, facility-wide emissions, and emissions from 
other facilities nearby).
    The Agency understands the potential importance of considering an 
individual's total exposure to HAP in addition to considering exposure 
to HAP emissions from the source category and facility. This is 
particularly important when assessing non-cancer risks, where 
pollutant-specific exposure levels (e.g., Reference Concentration 
(RfC)) are based on the assumption that thresholds exist for adverse 
health effects. For example, the Agency recognizes that, although 
exposures attributable to emissions from a source category or facility 
alone may not indicate the potential for increased risk of adverse non-
cancer health effects in a population, the exposures resulting from 
emissions from the facility in combination with emissions from all of 
the other sources (e.g., other facilities) to which an individual is 
exposed may be sufficient to result in increased risk of adverse non-
cancer health effects. In May 2010, the EPA Science Advisory Board 
(SAB) advised us ``* * * that RTR assessments will be most useful to 
decision makers and communities if results are presented in the broader 
context of aggregate and cumulative risks, including background 
concentrations and contributions from other sources in the area.'' \3\
---------------------------------------------------------------------------

    \3\ EPA's responses to this and all other key recommendations of 
the SAB's advisory on RTR risk assessment methodologies (which is 
available at: http://yosemite.epa.gov/sab/sabproduct.nsf/
4AB3966E263D943A8525771F00668381/$File/EPA-SAB-10-007-unsigned.pdf) 
are outlined in a memo to this rulemaking docket from David Guinnup 
entitled, EPA's Actions in Response to the Key Recommendations of 
the SAB Review of RTR Risk Assessment Methodologies.
---------------------------------------------------------------------------

    While we are interested in placing source category and facility-
wide HAP risks in the context of total HAP risks from all sources 
combined in the vicinity of each source, we are concerned about the 
uncertainties of doing so. At this point, we believe that such 
estimates of total HAP risks will

[[Page 65074]]

have significantly greater associated uncertainties than for the source 
category or facility-wide estimates, hence, compounding the uncertainty 
in any such comparison. This is because we have not conducted a 
detailed technical review of HAP emissions data for source categories 
and facilities that have not previously undergone an RTR review or are 
not currently undergoing such review. We are requesting comment on 
whether and how best to estimate and evaluate total HAP exposure in our 
assessments, and, in particular, on whether and how it might be 
appropriate to use information from EPA's National Air Toxics 
Assessment (NATA) to support such estimates. We are also seeking 
comment on how best to consider various types and scales of risk 
estimates when making our acceptability and ample margin of safety 
determinations under CAA section 112(f). Additionally, we are seeking 
recommendations for any other comparative measures that may be useful 
in the assessment of the distribution of HAP risks across potentially 
affected demographic groups.

C. What other actions are we addressing in this proposal?

    In this proposal, we are addressing three additional types of 
action for some or all of these six MACT standards. For eight source 
categories subject to three of the MACT standards, we identified 
significant emission sources within the categories for which standards 
were not previously developed. We are proposing MACT standards for 
these emission sources pursuant to CAA section 112(d)(2) and (3). For 
four source categories subject to two of the MACT standards, we are 
also proposing changes to correct editorial errors, to make 
clarifications, and to address issues with implementation or 
determining compliance. We are also proposing to revise requirements in 
each of the six MACT standards related to emissions during periods of 
startup, shutdown, and malfunction (SSM).
    The United States Court of Appeals for the District of Columbia 
Circuit vacated portions of two provisions in EPA's CAA section 112 
regulations governing the emissions of HAP during periods of SSM. 
Sierra Club v. EPA, 551 F.3d 1019 (District of Columbia Circuit, 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 (h)(1), 
that is part of a regulation, commonly referred to as the General 
Provisions Rule, that EPA promulgated under section 112 of the CAA. 
When incorporated into a CAA section 112(d) standard for a specific 
source category, these two provisions exempt sources within that source 
category from the requirement to comply with the otherwise applicable 
emission standard during periods of SSM. We are proposing to eliminate 
the SSM exemption in each of the six MACT standards addressed in this 
proposal. Consistent with Sierra Club v. EPA, we are proposing that the 
established standards in these rules apply at all times. We are also 
proposing to revise the General Provisions table in each of the six 
MACT standards in several respects. For example, we are removing the 
General Provisions' requirement that the source develop an SSM plan. We 
are also removing certain recordkeeping and reporting requirements 
related to the SSM exemption, but we are retaining the recordkeeping 
and related requirements for malfunctions and request public comment on 
the requirements. EPA has attempted to ensure that regulatory language 
relating to the SSM exemption has been removed. We solicit comment on 
whether we have overlooked any regulatory provisions that might be 
inappropriate, unnecessary, or redundant based on our proposal to 
remove the exemption from compliance with the emission limit during 
periods of SSM.
    Periods of startup, normal operations, and shutdown are all 
predictable and routine aspects of a source's operations. In 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). EPA believes that a malfunction should not be 
viewed as a distinct operating mode, and, therefore, any emissions that 
occur during malfunctions do not need to be factored into development 
of CAA section 112(d) standards, which, once promulgated, apply at all 
times. In Mossville Environmental Action Now v. EPA, 370 F.3d 1232, 
1242 (District of Columbia Circuit 2004), the Court upheld as 
reasonable standards that had factored in variability of emissions 
under all operating conditions. However, nothing in CAA section 112(d) 
or in case law requires that 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 (District 
of Columbia Circuit 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 EPA to account for malfunctions in 
setting emissions standards. For example, we note that CAA section 112 
uses the concept of ``best performing'' sources in defining MACT, the 
level of stringency that major source standards must meet. Applying the 
concept of ``best performing'' to a source that is malfunctioning 
presents significant difficulties. The goal of best performing sources 
is to operate in such a way as to avoid malfunctions of their units.
    Moreover, even if malfunctions were considered a distinct operating 
mode, we believe it would be impracticable to take malfunctions into 
account in setting CAA section 112(d) standards. 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 
each source category. Malfunctions can also vary in frequency, degree, 
and duration, further complicating standard setting.
    Under this proposal, in the event that a source fails to comply 
with the applicable CAA section 112(d) standards as a result of a 
malfunction event, 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. EPA would also consider whether the source's 
failure to comply with the CAA section 112(d) standard was, in fact, 
``sudden, infrequent, not reasonably preventable'' and was not instead 
``caused in part by poor maintenance or careless operation.'' 40 CRF 
63.2 (definition of malfunction).
    Finally, EPA recognizes that, even equipment that is properly 
designed and maintained can sometimes fail, and that such failure can 
sometimes cause or contribute to an exceedance of the relevant emission 
standard. (See, e.g., State Implementation Plans: Policy Regarding 
Excessive Emissions During Malfunctions, Startup, and Shutdown 
(September 20, 1999); Policy on Excess

[[Page 65075]]

Emissions During Startup, Shutdown, Maintenance, and Malfunctions 
(February 15, 1983)). Therefore, consistent with our recently 
promulgated final amendments to regulations addressing the Portland 
Cement category (75 FR 54970, September 9, 2010), we are proposing to 
add regulatory language providing an affirmative defense against civil 
penalties for exceedances of emission limits that are caused by 
malfunctions in each of the six MACT standards addressed in this 
proposal. We are proposing to define ``affirmative defense'' to mean, 
in the context of an enforcement proceeding, a response or defense put 
forward by a defendant, regarding which the defendant has the burden of 
proof, and the merits of which are independently and objectively 
evaluated in a judicial or administrative proceeding. We are also 
proposing regulatory provisions to specify the elements that are 
necessary to establish this affirmative defense. (See 40 CFR 22.24). 
The proposed criteria would ensure that the affirmative defense is 
available only where the event that causes an exceedance of the 
emission limit meets the narrow definition of malfunction in 40 CFR 
63.2 (sudden, infrequent, not reasonably preventable, and not caused by 
poor maintenance and/or careless operation). The proposed criteria also 
are designed to ensure that steps are taken to correct the malfunction, 
to minimize emissions, and to prevent future malfunctions. In any 
judicial or administrative proceeding, the Administrator would be able 
to challenge the assertion of the affirmative defense and, if the 
respondent has not met its burden of proving all of the requirements in 
the affirmative defense, appropriate penalties could be assessed in 
accordance with section 113 of the CAA (see also 40 CFR 22.77).

D. What specific RTR actions have previously been taken for these 
source categories?

    For some of the 16 source categories covered by these six MACT 
standards, we have previously taken certain actions under the RTR 
program. Following is a summary of these previous actions and also a 
summary of additional reviews we have subsequently conducted for each 
source category.
1. Categories for Which RTR Decisions Have Been Finalized
    There are nine source categories regulated under the Group I 
Polymers and Resins MACT standard. For four of these source categories 
(Butyl Rubber Production, Ethylene Propylene Rubber Production, 
Neoprene Production, and Polysulfide Rubber Production), we previously 
proposed and promulgated a decision not to revise the standards for 
purposes of the RTR provisions in CAA sections 112(d)(6) and (f)(2).\4\ 
See 72 FR 70543, December 12, 2007 (proposed rule), and 73 FR 76220, 
December 16, 2008 (final rule). These four categories were determined 
to be ``low-risk,'' as the maximum lifetime individual cancer risks 
were less than 1-in-1-million, and there were no other health concerns 
of significance. Therefore, we determined that conducting additional 
risk analyses for these categories was not warranted. We are not re-
opening the RTR in this notice for these four source categories, and do 
not seek additional comments on that prior RTR.
---------------------------------------------------------------------------

    \4\ There are no longer any operating facilities in the United 
States that produce polysulfide rubber, and we do not anticipate any 
will begin to operate in the future.
---------------------------------------------------------------------------

    However, for three of these four Group I Polymers and Resins source 
categories (Butyl Rubber Production, Ethylene Propylene Rubber 
Production, and Neoprene Production), we have identified significant 
emission sources for which MACT standards were not previously 
developed. In this proposal, we are proposing MACT standards for these 
emission sources, and we are also proposing that the residual risks 
after implementation of these new MACT standards will not change our 
previous finding that these source categories present low risks and 
that our obligation to review the residual risk under CAA section 
112(f) has also been satisfied.
2. Categories for Which RTR Decisions Have Been Proposed, but Not 
Promulgated
    For eight source categories covered under four of the MACT 
standards addressed in this proposal, we previously performed an RTR 
review and proposed that no revisions of the MACT standards were 
necessary to address residual risk and that it was not necessary to 
revise the existing standards under CAA section 112(d)(6). See 73 FR 
60423, October 10, 2008. The MACT standards addressed in this proposal 
included Marine Tank Vessel Loading Operations (MTVLO), Printing and 
Publishing Industry, Pharmaceuticals Production, and five of the source 
categories covered under Group I Polymers and Resins (Epichlorohydrin 
Elastomers, Hypalon\TM\ Production, Nitrile Butadiene Rubber 
Production, Polybutadiene Rubber Production, and Styrene Butadiene 
Rubber and Latex Production).\5\ Comments were received on that 
proposal, but no final action has been taken. This proposal presents 
additional analyses we have performed since the proposal, for each of 
these source categories with regard to the RTR. In addition, we are 
proposing revisions to the SSM provisions in the existing standards for 
these source categories, and, for several of the source categories, we 
are proposing MACT standards under CAA sections 112(d)(2) and (3) for 
emission points that were not previously regulated.
---------------------------------------------------------------------------

    \5\ The Mineral Wool Production source category was also 
addressed in that same October 2008 proposal. We are not proposing 
any additional action for that source category in this proposal, but 
will do so in a separate future action. We note that there are no 
longer any operating facilities in the United States that produce 
Hypalon\TM\, and we do not anticipate that any will begin operation 
in the future.
---------------------------------------------------------------------------

3. Categories for Which RTR Decisions Have Not Been Proposed
    We have not previously proposed any RTR actions for the four source 
categories (Hard and Decorative Chromium Electroplating, Chromium 
Anodizing Tanks, and Steel Pickling--HCl Process Facilities and 
Hydrochloric Acid Regeneration Plants) covered by the Chromium 
Electroplating and Steel Pickling MACT standards. Therefore, this is 
our initial proposed action for these two MACT standards to address the 
RTR requirement. In addition, we identified significant advances in the 
housekeeping requirements in the chromium source categories for which 
we are proposing MACT standards. We are also proposing revisions to the 
provisions addressing SSM to ensure they are consistent with the Court 
decision in Sierra Club v. EPA, 551 F.3d 1019, and we are proposing 
changes to correct editorial errors, make clarifications, or address 
issues with implementation or determining compliance.

IV. Analyses Performed

    As discussed above, in this notice, we are taking the following 
actions: (1) We are newly proposing action or supplementing our 
previous proposal to address the RTR requirements of CAA sections 
112(d)(6) and (f)(2) for 16 source categories covered by six different 
MACT standards; (2) for eight of the source categories, we are 
proposing MACT standards for significant emission sources that are not 
currently subject to emission standards under the MACT standards; (3) 
we are proposing to revise the provisions in each of these six MACT 
standards to address SSM to ensure that the SSM provisions are 
consistent with the Court

[[Page 65076]]

decision in Sierra Club v. EPA, 551 F. 3d 1019; and (4) for two of the 
MACT standards, we are proposing amendments to correct editorial 
errors, to make clarifications, and to address issues with 
implementation or determining compliance.

A. How did we estimate risk posed by the source categories?

    To support the proposed decision under the RTR for each source 
category, EPA conducted risk assessments that provided estimates of the 
MIR posed by the HAP emissions from each source in a category and by 
each source category, the distribution of cancer risks within the 
exposed populations, cancer incidence, HI for chronic exposures to HAP 
with non-cancer health effects, hazard quotients (HQ) for acute 
exposures to HAP with non-cancer health effects, and an evaluation of 
the potential for adverse environmental effects. The risk assessments 
consisted of seven primary steps, as discussed below.
    The docket for this rulemaking contains the following documents 
which provide more information on the risk assessment inputs and 
models, Draft Residual Risk Assessment for 9 Source Categories, Draft 
Residual Risk Assessment for Steel Pickling, and Draft Residual Risk 
Assessment for Chromium Electroplating, as well as the memoranda for 
the Printing and Publishing Industry, MTVLO, Epichlorohydrin Elastomers 
Production, Polybutadiene Rubber Production, Styrene Butadiene Rubber 
Production, Nitrile Butadiene Production, and Pharmaceuticals 
Production source categories.
1. Establishing the Nature and Magnitude of Actual Emissions and 
Identifying the Emissions Release Characteristics
    For the source categories included in the October 10, 2008, 
proposal, we compiled preliminary data sets using readily-available 
information, reviewed the data, and made changes where necessary, and 
shared these data with the public via an Advanced Notice of Proposed 
Rulemaking (ANPRM). 72 FR 29287, March 29, 2007. The data sets were 
then updated based on comments received on the ANPRM and, in some 
cases, with additional information gathered by EPA. For the five Group 
I Polymers and Resins I Production source categories included in the 
October 2008 proposal (Epichlorohydrin Elastomers Production, 
Hypalon\TM\ Production, Nitrile Butadiene Rubber Production, 
Polybutadiene Rubber Production, and Styrene Butadiene Rubber and Latex 
Production), the preliminary data sets were based on information we 
collected directly from industry on emissions data and emissions 
release characteristics. For the MTVLO, Pharmaceuticals Production, and 
the Printing and Publishing Industry source categories, we created the 
preliminary data sets using data in the 2002 National Emissions 
Inventory (NEI) Final Inventory, Version 1 (made publicly available on 
February 26, 2006), supplemented by data collected directly from 
industry when available. The NEI is a database that contains 
information about sources that emit criteria air pollutants and their 
precursors, and HAP. The database includes estimates of annual air 
pollutant emissions from point, nonpoint, and mobile sources in the 50 
States, the District of Columbia, Puerto Rico, and the Virgin Islands. 
The EPA collects this information and releases an updated version of 
the NEI database every 3 years.
    In the March 29, 2007, ANPRM, we specifically requested comment on, 
and updates to, these preliminary data sets. We received comments on 
emissions data and emissions release characteristics data for 
facilities in these source categories. These comments were reviewed, 
considered, and the emissions information was adjusted where we 
concluded the comments supported such adjustment. After incorporation 
of changes to the data sets from this public data review process, data 
sets were created that were used to conduct the risk assessments and 
other analyses that formed the basis for the proposed actions included 
in the October 10, 2008, proposal.
    Since the proposal, we have continued to scrutinize the data sets 
for these source categories and to review additional data that has 
become available since the October 10, 2008, proposal. For the Printing 
and Publishing Industry source category, we became aware that some 
facilities had closed. We also reviewed the emissions data and had 
questions about the emissions of certain HAP. After contact with 
industry, it was determined that those emissions did not occur from 
those facilities. We updated the Printing and Publishing Industry data 
set to reflect these changes in operating facilities and emissions. For 
the MTVLO data set, we had concerns that several emission points in our 
existing data set were mislabeled, and, thus, we extracted more recent 
data from the NEI. For this source category, the data set is based on 
the 2005 NEI. For the Pharmaceuticals Production source category data 
set, no changes are necessary to the data set used for the proposal. 
For the Polymers and Resins I MACT standard source categories included 
in the October 10, 2008, proposal, updates have been made based on 
information received in response to an industry information collection 
survey. Documentation for industry contacts, surveys, and other 
information gathered to support these changes is available in the 
docket for this action.
    For the four source categories not included in the December 10, 
2008, proposal, we compiled preliminary data sets using the best 
available information, reviewed the data, and made changes where 
necessary. For the three Chromium Electroplating MACT standard source 
categories (Chromium Anodizing Tanks, Decorative Chromium 
Electroplating, and Hard Chromium Electroplating) and the Steel 
Pickling source category, we compiled the preliminary data sets using 
data in the 2005 NEI. Then, for the Steel Pickling source category, 
seven facilities were contacted to verify their emissions and emissions 
release characteristic data, and we updated the data set based on the 
information collected. This updated data set was used to conduct the 
risk assessments and other analyses that form the bases for the 
proposed actions.
    For the Chromium Electroplating source categories, a review of the 
2005 NEI data indicated that not all chromium electroplating facilities 
were included in the data set. To develop an emissions inventory for 
the entire industry that could be used for modeling, an additional data 
set was developed based on facilities with known addresses--a total of 
1,629 facilities compared to 122 facilities in the NEI. Emissions for 
each type of plant were estimated based on the model plants developed 
for the original Chromium Electroplating MACT standard,\6\ with hard 
chromium model plants having the highest emissions, followed by 
decorative chromium electroplating, and then chromium anodizing. If the 
type of electroplating performed at a specific plant was unknown, we 
assumed these facilities were hard chrome electroplating when we 
estimated emissions and risks for those facilities. Although we knew 
that, by doing so, we would be overestimating emissions of chromium, 
and, therefore, also of risk, we made this conservative assumption 
because we did not have complete information, and we chose to 
overestimate to preserve an

[[Page 65077]]

ample margin of safety in the risk assessment upon which our risk 
modeling would be based. This analysis and a supplemental assessment 
are fully described in section V.A.
---------------------------------------------------------------------------

    \6\ See EPA-HQ-OAR-2010-0600, Model Plant Data Used to Estimate 
Risk from Chromium Electroplating Sources.
---------------------------------------------------------------------------

2. Establishing the Relationship Between Actual Emissions and MACT-
Allowable Emissions Levels
    The available emissions data in the NEI and from other sources 
typically represent the mass of emissions actually emitted during the 
specified annual time period. These ``actual'' emission levels are 
often lower than the level of emissions that a facility might be 
allowed to emit and still comply with the MACT standard. The emissions 
level allowed to be emitted by the MACT standard is referred to as the 
``MACT-allowable'' emissions level. This represents the highest 
emission level that could be emitted by the facility without violating 
the MACT standard.
    We discussed the use of both MACT-allowable and actual emissions in 
the final Coke Oven Batteries residual risk rule (70 FR 19998-19999, 
April 15, 2005) and in the proposed and final Hazardous Organic NESHAP 
(HON) residual risk rules (71 FR 34428, June 14, 2006, and 71 FR 76609, 
December 21, 2006, respectively). In those previous actions, we noted 
that assessing the risks at the MACT-allowable level is inherently 
reasonable since these risks reflect the maximum level sources could 
emit and still comply with national emission standards. But we also 
explained that it is reasonable to consider actual emissions, where 
such data are available, in both steps of the risk analysis, in 
accordance with the Benzene NESHAP. (54 FR 38044, September 14, 1989.) 
It is reasonable to consider actual emissions because sources typically 
seek to perform better than required by emission standards to provide 
an operational cushion to accommodate the variability in manufacturing 
processes and control device performance.
    As described above, the actual emissions data were compiled based 
on the NEI, information gathered from facilities and States, and 
information received in response to the ANPRM for several of the source 
categories. To estimate emissions at the MACT-allowable level, we 
developed a ratio of MACT-allowable to actual emissions for each 
emissions source type in each source category, based on the level of 
control required by the MACT standard compared to the level of reported 
actual emissions and available information on the level of control 
achieved by the emissions controls in use. For example, if there was 
information to suggest several facilities in a source category were 
controlling storage tank emissions by 98 percent while the MACT 
standards required only 92-percent control, we would estimate that 
MACT-allowable emissions from these emission points could be as much as 
four times higher (8-percent allowable emissions compared with 2-
percent actually emitted), and the ratio of MACT-allowable to actual 
would be 4:1 for this emission point type at the facilities in this 
source category. After developing these ratios for each emission point 
type in each source category, we next applied these ratios on a 
facility-by-facility basis to the maximum chronic risk values from the 
inhalation risk assessment to obtain facility-specific maximum risk 
values based on MACT-allowable emissions.
3. Conducting Dispersion Modeling, Determining Inhalation Exposures, 
and Estimating Individual and Population Inhalation Risks
    Both long-term and short-term inhalation exposure concentrations 
and health risks from each of the source categories addressed in this 
proposal were estimated using the Human Exposure Model (Community and 
Sector HEM-3 version 1.1.0). The HEM-3 performs three of the primary 
risk assessment activities listed above: (1) Conducting dispersion 
modeling to estimate the concentrations of HAP in ambient air, (2) 
estimating long-term and short-term inhalation exposures to individuals 
residing within 50 km of the modeled sources, and (3) estimating 
individual and population-level inhalation risks using the exposure 
estimates and quantitative dose-response information.
    The dispersion model used by HEM-3 is AERMOD, which is one of EPA's 
preferred models for assessing pollutant concentrations from industrial 
facilities.\7\ To perform the dispersion modeling and to develop the 
preliminary risk estimates, HEM-3 draws on three data libraries. The 
first is a library of meteorological data, which is used for dispersion 
calculations. This library includes 1 year of hourly surface and upper 
air observations for 130 meteorological stations, selected to provide 
coverage of the United States and Puerto Rico. A second library of 
United States Census Bureau census block \8\ internal point locations 
and populations provides the basis of human exposure calculations 
(Census, 2000). In addition, the census library includes the elevation 
and controlling hill height for each census block, which are also used 
in dispersion calculations. A third library of pollutant unit risk 
factors and other health benchmarks is used to estimate health risks. 
These risk factors and health benchmarks are the latest values 
recommended by EPA for HAP and other toxic air pollutants. These values 
are available at http://www.epa.gov/ttn/atw/toxsource/summary.html and 
are discussed in more detail later in this section.
---------------------------------------------------------------------------

    \7\ U.S. EPA. Revision to the Guideline on Air Quality Models: 
Adoption of a Preferred General Purpose (Flat and Complex Terrain) 
Dispersion Model and Other Revisions (70 FR 68218, November 9, 
2005).
    \8\ A census block is generally the smallest geographic area for 
which census statistics are tabulated.
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    In developing the risk assessment for chronic exposures, we used 
the estimated annual average ambient air concentration of each of the 
HAP emitted by each source for which we have emissions data in the 
source category. The air concentrations at each nearby census block 
centroid were used as a surrogate for the chronic inhalation exposure 
concentration for all the people who reside in that census block. We 
calculated the MIR for each facility as the cancer risk associated with 
a lifetime (70-year period) of exposure to the maximum concentration at 
the centroid of an inhabited census block. Individual cancer risks were 
calculated as the lifetime exposure to the ambient concentration of 
each of the HAP multiplied by its Unit Risk Estimate (URE), which is an 
upper bound estimate of an individual's probability of contracting 
cancer over a lifetime of exposure to a concentration of 1 microgram of 
the pollutant per cubic meter of air. For residual risk assessments, we 
generally use URE values from EPA's Integrated Risk Information System 
(IRIS).\9\ For carcinogenic pollutants without EPA IRIS values, we look 
to other reputable sources of cancer dose-response values, often using 
California Environmental Protection Agency (CalEPA) URE values, where 
available. In cases where new, scientifically credible dose response 
values have been developed in a manner consistent with EPA guidelines 
and have undergone a peer review process similar to that used by EPA, 
we may use such dose-response values in place of, or in addition to, 
other values.
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    \9\ The IRIS information is available at http://www.epa.gov/
IRIS.

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[[Page 65078]]

    We note here that several carcinogens have a mutagenic mode of 
action.\10\ For these compounds, the age-dependent adjustment factors 
described in EPA's Supplemental Guidance for Assessing Susceptibility 
from Early-Life Exposure to Carcinogens \11\ were applied. This 
adjustment has the effect of increasing the estimated lifetime risks 
for these pollutants by a factor of 1.6.\12\ In addition, although only 
a small fraction of the total polycyclic organic matter (POM) emissions 
were reported as individual compounds, EPA expresses carcinogenic 
potency for compounds in this group in terms of benzo[a]pyrene 
equivalence, based on evidence that carcinogenic POM have the same 
mutagenic mechanism of action as does benzo[a]pyrene. For this reason, 
EPA's Science Policy Council \13\ recommends applying the Supplemental 
Guidance to all carcinogenic polycyclic aromatic hydrocarbons for which 
risk estimates are based on relative potency. Accordingly, we have 
applied the Supplemental Guidance to all unspeciated POM mixtures.
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    \10\ U.S. EPA, 2006. Performing risk assessments that include 
carcinogens described in the Supplemental Guidance as having a 
mutagenic mode of action. Science Policy Council Cancer Guidelines 
Implementation Workgroup Communication II: Memo from W.H. Farland 
dated June 14, 2006. http://epa.gov/osa/spc/pdfs/
CGIWGCommunication_II.pdf.
    \11\ U.S. EPA, 2005. Supplemental Guidance for Assessing Early-
Life Exposure to Carcinogens. EPA/630/R-03/003F. http://www.epa.gov/
ttn/atw/childrens_supplement_final.pdf.
    \12\ Only one of these mutagenic compounds, benzo[a]pyrene, is 
emitted by any of the sources covered by this proposal.
    \13\ U.S. EPA, 2005. Science Policy Council Cancer Guidelines 
Implementation Workgroup Communication I: Memo from W.H. Farland 
dated October 4, 2005, to Science Policy Council. http://
www.epa.gov/osa/spc/pdfs/canguid1.pdf.
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    Incremental individual lifetime cancer risks associated with 
emissions from the source category were estimated as the sum of the 
risks for each of the carcinogenic HAP (including those classified as 
carcinogenic to humans, likely to be carcinogenic to humans, and 
suggestive evidence of carcinogenic potential \14\) emitted by the 
modeled source. Cancer incidence and the distribution of individual 
cancer risks for the population within 50 km of any source were also 
estimated for the source category as part of these assessments by 
summing individual risks. A distance of 50 km is consistent with both 
the analysis supporting the 1989 Benzene NESHAP (54 FR 38044) and the 
limitations of Gaussian dispersion modeling.
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    \14\ These classifications also coincide with the terms ``known 
carcinogen, probable carcinogen, and possible carcinogen,'' 
respectively, which are the terms advocated in the EPA's previous 
Guidelines for Carcinogen Risk Assessment, published in 1986 (51 FR 
33992, September 24, 1986). Summing the risks of these individual 
compounds to obtain the cumulative cancer risks is an approach that 
was recommended by the EPA's SAB in their 2002 peer review of EPA's 
NATA entitled, NATA--Evaluating the National-scale Air Toxics 
Assessment 1996 Data--an SAB Advisory, available at: http://
yosemite.epa.gov/sab/sabproduct.nsf/
214C6E915BB04E14852570CA007A682C/$File/ecadv02001.pdf.
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    To assess risk of non-cancer health effects from chronic exposures, 
we summed the HQ for each of the HAP that affects a common target organ 
system to obtain the HI for that target organ system (or target organ-
specific HI, TOSHI). The HQ is the estimated exposure divided by the 
chronic reference level, which is either the U.S. EPA RfC, defined as 
``an estimate (with uncertainty spanning perhaps an order of magnitude) 
of a continuous inhalation exposure to the human population (including 
sensitive subgroups) that is likely to be without an appreciable risk 
of deleterious effects during a lifetime,'' or, in cases where an RfC 
is not available, the CalEPA Chronic Reference Exposure Level (REL), 
defined as ``the concentration level at or below which no adverse 
health effects are anticipated for a specified exposure duration.'' As 
noted above, in cases where new, scientifically credible dose-response 
values have been developed in a manner consistent with EPA guidelines 
and have undergone a peer review process similar to that used by EPA, 
we may use those dose-response values in place of, or in addition to, 
other values.
    Screening estimates of acute exposures and risks were also 
evaluated for each of the HAP at the point of highest off-site exposure 
for each facility (i.e., not just the census block centroids) assuming 
that a person is located at this spot at a time when both the peak 
(hourly) emission rate and hourly dispersion conditions (1991 calendar 
year data) occur. In each case, acute HQ values were calculated using 
best available, short-term health threshold values. These acute 
threshold values include REL, Acute Exposure Guideline Levels (AEGL), 
and Emergency Response Planning Guidelines (ERPG) for 1-hour exposure 
durations. As discussed below, we used conservative assumptions for 
emission rates, meteorology, and exposure location for our acute 
analysis.
    As described in the CalEPA's Air Toxics Hot Spots Program Risk 
Assessment Guidelines, Part I, The Determination of Acute Reference 
Exposure Levels for Airborne Toxicants, an acute REL value (http://
www.oehha.ca.gov/air/pdf/acuterel.pdf) is defined as ``the 
concentration level at or below which no adverse health effects are 
anticipated for a specified exposure duration is termed the REL. REL 
values are based on the most sensitive, relevant, adverse health effect 
reported in the medical and toxicological literature. REL values are 
designed to protect the most sensitive individuals in the population by 
the inclusion of margins of safety. Since margins of safety are 
incorporated to address data gaps and uncertainties, exceeding the REL 
value does not automatically indicate an adverse health impact.''
    AEGL values were derived in response to recommendations from the 
National Research Council (NRC). As described in ``Standing Operating 
Procedures (SOP) of the National Advisory Committee on Acute Exposure 
Guideline Levels for Hazardous Substances'' (http://www.epa.gov/
opptintr/aegl/pubs/sop.pdf),\15\ ``the NRC's previous name for acute 
exposure levels--community emergency exposure levels (CEEL)-- was 
replaced by the term AEGL to reflect the broad application of these 
values to planning, response, and prevention in the community, the 
workplace, transportation, the military, and the remediation of 
Superfund sites.'' This document also states that AEGL values 
``represent threshold exposure limits for the general public and are 
applicable to emergency exposures ranging from 10 minutes to 8 hours.'' 
The document lays out the purpose and objectives of AEGL by stating 
(page 21) that ``the primary purpose of the AEGL program and the NAC/
AEGL Committee is to develop guideline levels for once-in-a-lifetime, 
short-term exposures to airborne concentrations of acutely toxic, high-
priority chemicals.'' In detailing the intended application of AEGL 
values, the document states (page 31) that ''[i]t is anticipated that 
the AEGL values will be used for regulatory and nonregulatory purposes 
by United States Federal and State agencies, and possibly the 
international community in conjunction with chemical emergency 
response, planning, and prevention programs. More specifically, the 
AEGL values will be used for conducting various risk assessments to aid 
in the development of emergency preparedness and prevention plans, as 
well as real-time emergency response actions, for accidental chemical 
releases at fixed facilities and from transport carriers.''
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    \15\ NAS, 2001. Standing Operating Procedures for Developing 
Acute Exposure Levels for Hazardous Chemicals, page 2.

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[[Page 65079]]

    The AEGL-1 value is then specifically defined as ``the airborne 
concentration of a substance above which it is predicted that the 
general population, including susceptible individuals, could experience 
notable discomfort, irritation, or certain asymptomatic nonsensory 
effects. However, the effects are not disabling and are transient and 
reversible upon cessation of exposure.'' The document also notes (page 
3) that, ``Airborne concentrations below AEGL-1 represent exposure 
levels that can produce mild and progressively increasing but transient 
and nondisabling odor, taste, and sensory irritation or certain 
asymptomatic, nonsensory effects.'' Similarly, the document defines 
AEGL-2 values as ``the airborne concentration (expressed as ppm or mg/
m\3\) of a substance above which it is predicted that the general 
population, including susceptible individuals, could experience 
irreversible or other serious, long-lasting adverse health effects or 
an impaired ability to escape.''
    ERPG values are derived for use in emergency response, as described 
in the American Industrial Hygiene Association's document entitled, 
Emergency Response Planning Guidelines (ERPG) Procedures and 
Responsibilities (http://www.aiha.org/1documents/committees/
ERPSOPs2006.pdf), which states that, ``Emergency Response Planning 
Guidelines were developed for emergency planning and are intended as 
health-based guideline concentrations for single exposures to 
chemicals.'' \16\ The ERPG-1 value is defined as ``the maximum airborne 
concentration below which it is believed that nearly all individuals 
could be exposed for up to 1 hour without experiencing other than mild 
transient adverse health effects or without perceiving a clearly 
defined, objectionable odor.'' Similarly, the ERPG-2 value is defined 
as ``the maximum airborne concentration below which it is believed that 
nearly all individuals could be exposed for up to 1 hour without 
experiencing or developing irreversible or other serious health effects 
or symptoms which could impair an individual's ability to take 
protective action.''
---------------------------------------------------------------------------

    \16\ ERP Committee Procedures and Responsibilities. 1 November 
2006. American Industrial Hygiene Association.
---------------------------------------------------------------------------

    As can be seen from the definitions above, the AEGL and ERPG values 
include the similarly-defined severity levels 1 and 2. For many 
chemicals, a severity level 1 value AEGL or ERPG has not been 
developed; in these instances, higher severity level AEGL-2 or ERPG-2 
values are compared to our modeled exposure levels to screen for 
potential acute concerns.
    Acute REL values for 1-hour exposure durations are typically lower 
than their corresponding AEGL-1 and ERPG-1 values. Even though their 
definitions are slightly different, AEGL-1 values are often the same as 
the corresponding ERPG-1 values, and AEGL-2 values are often equal to 
ERPG-2 values. Maximum HQ values from our acute screening risk 
assessments typically result when basing them on the acute REL value 
for a particular pollutant. In cases where our maximum acute HQ value 
exceeds 1, we also report the HQ value based on the next highest acute 
threshold (usually the AEGL-1 and/or the ERPG-1 value).
    To develop screening estimates of acute exposures, we developed 
estimates of maximum hourly emission rates by multiplying the average 
actual annual hourly emission rates by a factor to cover routinely 
variable emissions. We chose the factor to use based on process 
knowledge and engineering judgment and with awareness of a Texas study 
of short-term emissions variability, which showed that most peak 
emission events, in a heavily-industrialized 4-county area (Harris, 
Galveston, Chambers, and Brazoria Counties, Texas), were less than 
twice the annual average hourly emission rate, and the highest peak 
emission event was 8.5 times the annual average hourly emission 
rate.\17\ This analysis is provided in Appendix 4 of the Draft Residual 
Risk Assessment for Source Categories Report and is available in the 
docket for this action. Considering this analysis, unless specific 
process knowledge provided an alternate value, a conservative screening 
multiplication factor of 10 was applied to the average annual hourly 
emission rate in these acute exposure screening assessments.
---------------------------------------------------------------------------

    \17\ See http://www.tceq.state.tx.us/compliance/field_ops/eer/
index.html or docket to access the source of these data.
---------------------------------------------------------------------------

    In cases where all acute HQ values from the screening step were 
less than or equal to 1, acute impacts were deemed negligible and no 
further analysis was performed. In the cases where an acute HQ from the 
screening step was greater than 1, additional site-specific data were 
considered to develop a more refined estimate of the potential for 
acute impacts of concern. The data refinements considered included 
using a peak-to-mean hourly emissions ratio based on source category-
specific knowledge or data (rather than the default factor of 10) and 
using the site-specific facility layout to distinguish facility 
property from an area where the public could be exposed. Ideally, we 
would prefer to have continuous measurements over time to see how the 
emissions vary by each hour over an entire year. Having a frequency 
distribution of hourly emission rates over a year would allow us to 
perform a probabilistic analysis to estimate potential threshold 
exceedances and their frequency of occurrence. Such an evaluation could 
include a more complete statistical treatment of the key parameters and 
elements adopted in this screening analysis. However, we recognize that 
having this level of data is rare, hence our use of the multiplier 
approach.
4. Conducting Multipathway Exposure and Risk Modeling
    The potential for significant human health risks due to exposures 
via routes other than inhalation (i.e., multipathway exposures) and the 
potential for adverse environmental impacts were evaluated in a three-
step process. In the first step, we determined whether any facilities 
emitted any HAP known to be persistent and bio-accumulative in the 
environment (PB-HAP). There are 14 PB-HAP compounds or compound classes 
identified for this screening in EPA's Air Toxics Risk Assessment 
Library (available at http://www.epa.gov/ttn/fera/risk_atra_
vol1.html). They are cadmium compounds, chlordane, chlorinated 
dibenzodioxins and furans, dichlorodiphenyldichloroethylene, 
heptachlor, hexachlorobenzene, hexachlorocyclohexane, lead compounds, 
mercury compounds, methoxychlor, polychlorinated biphenyls, POM, 
toxaphene, and trifluralin.
    In the second step of the screening process, we determined whether 
the facility-specific emission rates of each of the emitted PB-HAP were 
large enough to create the potential for significant non-inhalation 
risks. To facilitate this step, we have developed emission rate 
thresholds for each PB-HAP using a hypothetical screening exposure 
scenario developed for use in conjunction with the TRIM.FaTE model. The 
hypothetical screening scenario was subjected to a sensitivity analysis 
to ensure that its key design parameters were established such that 
environmental media concentrations were not underestimated (i.e., to 
minimize the occurrence of false negatives, or results that suggest 
that risks might be acceptable when, in fact, actual risks are high), 
and to also minimize the occurrence of false positives for human health 
endpoints.

[[Page 65080]]

We call this application of the TRIM.FaTE model TRIM-Screen. The 
facility-specific emission rates of each of the PB-HAP in each source 
category were compared to the emission threshold values for each of the 
PB-HAP identified in the source category data sets.
    For all of the facilities in the source categories addressed in 
this proposal, all of the PB-HAP emission rates were less than the 
emission threshold values. As a result of this, multi-pathway exposures 
and environmental risks were deemed negligible and no further analysis 
was performed. If the emission rates of the PB-HAP had been above the 
emission threshold values, the source categories would have been 
further evaluated for potential non-inhalation risks and adverse 
environmental effects in a third step through site-specific refined 
assessments using EPA's TRIM.FaTE model.
    For further information on the multi-pathway analysis approach, see 
the residual risk documentation as referenced in section IV.A of this 
preamble.
5. Assessing Risks Considering Emissions Control Options
    In addition to assessing baseline inhalation risks and screening 
for potential multi-pathway risks, for some source categories, where 
appropriate, we also estimated risks considering the potential emission 
reductions that would be achieved by the particular control options 
under consideration. The inhalation and multi-pathway risks estimated, 
as described above, at the actual and MACT-allowable levels represent 
the actual and maximum allowable operating conditions of the facilities 
in the source categories analyzed. For source categories where emission 
reduction options were available, we estimated risk based on the 
expected emissions reductions that would be realized with those 
additional emissions controls. In these cases, the expected emissions 
reductions were applied to the specific HAP and emissions sources in 
the source category data set. The results of the risk analyses 
considering the application of emissions controls are included in the 
residual risk documentation as referenced in section IV.A of this 
preamble, which is available in the docket for this action.
6. Conducting Other Risk-Related Analyses, Including Facility-Wide 
Assessments and Demographic Analyses
a. Facility-Wide Risk
    To put the source category risks in context, we also examined the 
risks from the entire ``facility,'' where the facility includes all 
HAP-emitting operations within a contiguous area and under common 
control. In other words, for each facility that includes one or more 
sources from one of the source categories under review, we examined the 
HAP emissions not only from the source category of interest, but also 
emissions of HAP from all other emission sources at the facility. The 
emissions data for generating these ``facility-wide'' risks were 
obtained from the 2005 NEI (available at http://www.epa.gov/chief/net/
2005inventory.html). We analyzed risks due to the inhalation of HAP 
that are emitted ``facility-wide'' for the populations residing within 
50 km of each facility, consistent with the methods used for the source 
category analysis described above. For these facility-wide risk 
analyses, the modeled source category risks were compared to the 
facility-wide risks to determine the portion of facility-wide risks 
that could be attributed to each of the six source categories being 
addressed in this proposal, we specifically examined the facility that 
was associated with the highest estimate of risk and determined the 
percentage of that risk attributable to the source category of 
interest. The risk documentation available through the docket for this 
action provides all the facility-wide risks and the percentage of 
source category contribution for all source categories assessed.
    The methodology and the results of the facility-wide analyses for 
each source category are included in the residual risk documentation as 
referenced in section IV.A of this preamble, which is available in the 
docket for this action.
b. Demographic Analysis
    To examine the potential for any environmental justice issues that 
might be associated with each source category, we evaluated the 
distributions of HAP-related cancer and non-cancer risks across 
different social, demographic, and economic groups within the 
populations living near the facilities where these source categories 
are located. The development of demographic analyses to inform the 
consideration of environmental justice issues in EPA rulemakings is an 
evolving science. The EPA offers the demographic analyses in this 
rulemaking as examples of how such analyses might be developed to 
inform such consideration, and invites public comment on the approaches 
used and the interpretations made from the results, with the hope that 
this will support the refinement and improve utility of such analyses 
for future rulemakings.
    For this analysis, we analyzed risks due to the inhalation of HAP 
in two separate ways. In the first approach, we focus the analysis on 
the total populations residing within 5 km of each facility (source 
category and facility-wide), regardless of their estimated risks, and 
examine the distributions of estimated risk across the various 
demographic groups within those 5 km circles. The distance of 5 km was 
chosen for the first approach to be consistent with previous 
demographic analyses performed at EPA, such as the one which was 
performed in support of the recent proposal for the Boilers NESHAP. In 
the second approach, we focus the analysis only on the populations 
within 5 km \18\ of any facility estimated to have exposures to HAP 
which result in cancer risks of 1-in-1 million or greater or non-cancer 
hazard indices of 1 or greater (based on the emissions of the source 
category or the facility, respectively). Once again, we examine the 
distributions of those risks across various demographic groups. In each 
approach, we compare the percentages of particular demographic groups 
to the total number of people in those demographic groups nationwide. 
In this preamble, we only present the results of the second approach 
since it focuses on the significant risks from either the source 
category or the facility-wide emissions. The results of both approaches 
including other risk metrics such as average risks for the exposed 
populations are documented in source category-specific technical 
reports in the docket for each of the source categories covered in this 
proposal.\19\
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    \18\ Generally, we have found that using a 5 km radius in the 
analysis will capture more than 90 percent of all the individuals 
with cancer risks above 1-in-1 million. In the future, we plan to 
extend these analyses to cover the entire modeled domain for a 
facility (50 km radius) to capture all individuals with risks above 
1-in-1 million from the affected facilities.
    \19\ For example, the report pertaining to the Hard Chromium 
Electroplating source category is entitled Risk and Technology 
Review--Analysis of Socio-Economic Factors for Populations Living 
Near Hard Chromium Electroplating Facilities.
---------------------------------------------------------------------------

    The basis for the risk values used in these analyses were the 
modeling results obtained from the HEM-3 model described above. The 
risk values for each census block were linked to a database of 
information from the 2000 Decennial census that includes data on race 
and ethnicity, age distributions, poverty status, household incomes, 
and education level. The Census Department Landview [supreg] database 
was the source of the data on race and ethnicity, and the

[[Page 65081]]

data on age distributions, poverty status, household incomes, and 
education level was obtained from the 2000 Census of Population and 
Housing Summary File 3 (SF3) Long Form. While race and ethnicity census 
data are available at the block group level, the age and income census 
data are only available at the census block level (which includes an 
average of 26 blocks or an average of 1,350 people). Where census data 
are available at the block group level but not the block level, we 
assumed that all blocks within the block group have the same 
distribution of ages and incomes as the block group.
    For each source category, the analysis results include the 
distribution of estimated lifetime inhalation cancer and chronic non-
cancer risks for different racial and ethnic groups, different age 
groups, adults with and without a high school diploma, people living in 
households below the national median income, and for people living 
below the poverty line among the population living near these 
facilities. The specific census population categories studied include:
     Total population.
     White.
     African American (or Black).
     Native Americans.
     Other races and multiracial.
     Hispanic or Latino.
     Children 18 years of age and under.
     Adults 19 to 64 years of age.
     Adults 65 years of age and over.
     Adults without a high school diploma.
     Households earning under the national median income.
     People living below the poverty line.
    It should be noted that these categories overlap in some instances, 
resulting in some populations being counted in more than one category 
(e.g., other races and multiracial and Hispanic). In addition, while 
not a specific census population category, we also examined risks to 
the category ``Minorities,'' which is defined as all race population 
categories except white. Since these demographic analysis methods are 
still evolving, EPA specifically solicits comment on the inclusion of 
other demographic categories (e.g., ``Hispanic and Non-white'') in our 
future analyses.
    For further information about risks to the populations local to the 
facilities in these source categories, we also evaluated the estimated 
distribution of inhalation cancer and chronic non-cancer risks 
associated with the HAP emissions from all the emissions sources at the 
facility (i.e., facility-wide). This analysis used the facility-wide 
RTR modeling results and the census data described above.
    The methodology and the results of the demographic analyses for 
each source category are included in the residual risk documentation as 
referenced in section IV.A of this preamble, which is available in the 
docket for this action.
7. Considering Uncertainties in Risk Assessment
    Uncertainty and the potential for bias are inherent in all risk 
assessments, including those performed for the source categories 
addressed in this proposal. Although uncertainty exists, we believe the 
approach that we took, which used conservative tools and assumptions, 
ensures that our decisions are health-protective. A brief discussion of 
the uncertainties in the emissions data sets, dispersion modeling, 
inhalation exposure estimates, and dose-response relationships follows 
below. A more thorough discussion of these uncertainties is included in 
the Draft Residual Risk Assessment for the Steel Pickling Source 
Category (July 2010), Draft Residual Risk Assessment for the Chromium 
Electroplating Source Category (July 2010), Draft Residual Risk 
Assessment for 9 Source Categories (August 2008), and the Risk and 
Technology Review (RTR) Assessment Plan (November 2006), each of which 
are available in the docket for this action.
a. Uncertainties in the Emissions Data Sets
    Although the development of the RTR data sets involved quality 
assurance/quality control processes, the accuracy of emissions values 
will vary depending on the source of the data, the degree to which data 
is incomplete or missing, the degree to which assumptions made to 
complete the data sets are inaccurate, errors in estimating emissions 
values, and other factors. The emission values considered in this 
analysis generally are annual totals that do not reflect short-term 
fluctuations during the course of a year or variations from year to 
year. In contrast, the estimates of peak hourly emission rates for the 
acute effects screening assessment were based on multiplication factors 
applied to the average annual hourly emission rates (the default factor 
is 10), which are intended to account for emission fluctuations due to 
normal facility operations. In some cases, more refined estimates were 
used for source categories where the screening estimates did not 
``screen out'' all sources and more specific information was available. 
Additionally, for some source categories our estimate of the number of 
facilities may not represent the number of facilities that we have in 
our notice of proposed rulemaking data set. There is also significant 
uncertainty for some source categories in the identification of sources 
as major or area in the NEI.
b. Uncertainties in Dispersion Modeling
    While the analysis employed EPA's recommended regulatory dispersion 
model, AERMOD, we recognize that there is uncertainty in ambient 
concentration estimates associated with any model, including AERMOD. 
Where possible, model options (e.g., rural/urban, plume depletion, 
chemistry) were selected to provide an overestimate of ambient air 
concentrations of the HAP. However, because of practicality and data 
limitation reasons, some factors (e.g., meteorology, building downwash) 
have the potential in some situations to overestimate or underestimate 
ambient impacts. For example, meteorological data were taken from a 
single year (1991), and facility locations can be a significant 
distance from the site where these data were taken. Despite these 
uncertainties, we believe that at off-site locations and census block 
centroids, the approach considered in the dispersion modeling analysis 
should generally yield overestimates of ambient HAP concentrations.
c. Uncertainties in Inhalation Exposure
    The effects of human mobility on exposures were not included in the 
assessment. Specifically, short-term mobility and long-term mobility 
between census blocks in the modeling domain were not considered.\20\ 
As a result, this simplification will likely bias the assessment toward 
overestimating the highest exposures. In addition, the assessment 
predicted the chronic exposures at the centroid of each populated 
census block as surrogates for the exposure concentrations for all 
people living in that block. Using the census block centroid to predict 
chronic exposures tends to over-predict exposures for people in the 
census block who live further from the facility and under-predict 
exposures for people in the census block who live closer to the 
facility. Thus, using the census block centroid to predict chronic 
exposures may lead to a potential understatement or overstatement of 
the true maximum

[[Page 65082]]

impact, but is an unbiased estimate of average risk and incidence.
---------------------------------------------------------------------------

    \20\ Short-term mobility is movement from one microenvironment 
to another over the course of hours or days. Long-term mobility is 
movement from one residence to another over the course of a 
lifetime.
---------------------------------------------------------------------------

    The assessments evaluate the cancer inhalation risks associated 
with pollutant exposures over a 70-year period, which is the assumed 
lifetime of an individual. In reality, both the length of time that 
modeled emissions sources at facilities actually operate (i.e., more or 
less than 70 years), and the domestic growth or decline of the modeled 
industry (i.e., the increase or decrease in the number or size of 
United States facilities), will influence the risks posed by a given 
source category. Depending on the characteristics of the industry, 
these factors will likely result in an overestimate (or possibly an 
underestimate in the extreme case where a facility maintains or 
increases its emission levels beyond 70 years and residents live beyond 
70 years at the same location) both in individual risk levels and in 
the total estimated number of cancer cases. Annual cancer incidence 
estimates from exposures to emissions from these sources would not be 
affected by uncertainty in the length of time emissions sources 
operate.
    The exposure estimates used in these analyses assume chronic 
exposures to ambient levels of pollutants. Because most people spend 
the majority of their time indoors, actual exposures may not be as 
high, depending on the characteristics of the pollutants modeled. For 
many HAP, indoor levels are roughly equivalent to ambient levels, but 
for very reactive pollutants or larger particles, these levels are 
typically lower. This factor has the potential to result in an 
overstatement of 25 to 30 percent of exposures.\21\
---------------------------------------------------------------------------

    \21\ U.S. EPA. National-Scale Air Toxics Assessment for 1996. 
(EPA 453/R-01-003; January 2001; page 85.)
---------------------------------------------------------------------------

    In addition to the uncertainties highlighted above, there are 
several factors specific to the acute exposure assessment that should 
be highlighted. The accuracy of an acute inhalation exposure assessment 
depends on the simultaneous occurrence of independent factors that may 
vary greatly, such as hourly emissions rates, meteorology, and human 
activity patterns. In this assessment, we assume that individuals 
remain for 1 hour at the point of maximum ambient concentration as 
determined by the co-occurrence of peak emissions and worst-case 
meteorological conditions. These assumptions would tend to overestimate 
actual exposures since it is unlikely that a person would be located at 
the point of maximum exposure during the time of worst-case impact.
d. Uncertainties in Dose-Response Relationships
    There are uncertainties inherent in the development of the 
reference values used in our risk assessments for cancer effects from 
chronic exposures and non-cancer effects from both chronic and acute 
exposures. Some uncertainties may be considered quantitatively, and 
others generally are expressed in qualitative terms. We note as a 
preface to this discussion a point on dose-response uncertainty that is 
brought out in EPA's 2005 Cancer Guidelines; namely, that ``the primary 
goal of EPA actions is protection of human health; accordingly, as an 
Agency policy, risk assessment procedures, including default options 
that are used in the absence of scientific data to the contrary, should 
be health protective.'' (EPA 2005 Cancer Guidelines, pages 1-7.) This 
is the approach followed here as summarized in the next several 
paragraphs. A complete detailed discussion of uncertainties and 
variabilities in dose-response relationships is given in the residual 
risk documentation as referenced in section IV.A of this preamble, 
which is available in the docket for this action.
    Cancer URE values used in our risk assessments are those that have 
been developed to generally provide an upper bound estimate of risk. 
That is, they represent a ``plausible upper limit to the true value of 
a quantity'' (although this is usually not a true statistical 
confidence limit).\22\ In some circumstances, the true risk could be as 
low as zero; however, in other circumstances the risk could also be 
greater.\23\ When developing an upper bound estimate of risk and to 
provide risk values that do not underestimate risk, health-protective 
default approaches are generally used. To err on the side of ensuring 
adequate health-protection, EPA typically uses the upper bound 
estimates rather than lower bound or central tendency estimates in our 
risk assessments, an approach that may have limitations for other uses 
(e.g., priority-setting or expected benefits analysis).
---------------------------------------------------------------------------

    \22\ IRIS glossary (http://www.epa.gov/NCEA/iris/help_
gloss.htm).
    \23\ An exception to this is the URE for benzene, which is 
considered to cover a range of values, each end of which is 
considered to be equally plausible, and which is based on maximum 
likelihood estimates.
---------------------------------------------------------------------------

    Chronic non-cancer reference (RfC and RfD) values represent chronic 
exposure levels that are intended to be health-protective levels. 
Specifically, these values provide an estimate (with uncertainty 
spanning perhaps an order of magnitude) of daily oral exposure (RfD) or 
of a continuous inhalation exposure (RfC) to the human population 
(including sensitive subgroups) that is likely to be without an 
appreciable risk of deleterious effects during a lifetime. To derive 
values that are intended to be ``without appreciable risk,'' the 
methodology relies upon an uncertainty factor (UF) approach (U.S. EPA, 
1993, 1994) which includes consideration of both uncertainty and 
variability. When there are gaps in the available information, UF are 
applied to derive reference values that are intended to protect against 
appreciable risk of deleterious effects. UF are commonly default 
values,\24\ e.g., factors of 10 or 3, used in the absence of compound-
specific data; where data are available, UF may also be developed using 
compound-specific information. When data are limited, more assumptions 
are needed and more UF are used. Thus, there may be a greater tendency 
to overestimate risk in the sense that further study might support 
development of reference values that are higher (i.e., less potent) 
because fewer default assumptions are needed. However, for some 
pollutants it is possible that risks may be underestimated.
---------------------------------------------------------------------------

    \24\ According to the NRC report, Science and Judgment in Risk 
Assessment (NRC, 1994) ``[Default] options are generic approaches, 
based on general scientific knowledge and policy judgment, that are 
applied to various elements of the risk assessment process when the 
correct scientific model is unknown or uncertain.'' The 1983 NRC 
report, Risk Assessment in the Federal Government: Managing the 
Process, defined default option as ``the option chosen on the basis 
of risk assessment policy that appears to be the best choice in the 
absence of data to the contrary'' (NRC, 1983a, p. 63). Therefore, 
default options are not rules that bind the Agency; rather, the 
Agency may depart from them in evaluating the risks posed by a 
specific substance when it believes this to be appropriate. In 
keeping with EPA's goal of protecting public health and the 
environment, default assumptions are used to ensure that risk to 
chemicals is not underestimated (although defaults are not intended 
to overtly overestimate risk). See EPA 2004, An examination of EPA 
Risk Assessment Principles and Practices, EPA/100/B-04/001 available 
at: http://www.epa.gov/osa/pdfs/ratf-final.pdf.
---------------------------------------------------------------------------

    While collectively termed ``UF,'' these factors account for a 
number of different quantitative considerations when using observed 
animal (usually rodent) or human toxicity data in the development of 
the RfC. The UF are intended to account for: (1) Variation in 
susceptibility among the members of the human population (i.e., inter-
individual variability); (2) uncertainty in extrapolating from 
experimental animal data to humans (i.e., interspecies differences); 
(3) uncertainty in extrapolating from data obtained in a study with 
less-than-lifetime exposure

[[Page 65083]]

(i.e., extrapolating from sub-chronic to chronic exposure); (4) 
uncertainty in extrapolating the observed data to obtain an estimate of 
the exposure associated with no adverse effects; and (5) uncertainty 
when the database is incomplete or there are problems with the 
applicability of available studies. Many of the UF used to account for 
variability and uncertainty in the development of acute reference 
values are quite similar to those developed for chronic durations, but 
they more often use individual UF values that may be less than 10. UF 
are applied based on chemical-specific or health effect-specific 
information (e.g., simple irritation effects do not vary appreciably 
between human individuals, hence a value of 3 is typically used), or 
based on the purpose for the reference value (see the following 
paragraph). The UF applied in acute reference value derivation include: 
(1) Heterogeneity among humans; (2) uncertainty in extrapolating from 
animals to humans; (3) uncertainty in lowest observable adverse effect 
(exposure) level to no observable effect (exposure) level adjustments; 
and (4) uncertainty in accounting for an incomplete database on toxic 
effects of potential concern. Additional adjustments are often applied 
to account for uncertainty in extrapolation from observations at one 
exposure duration (e.g., 4 hours) to derive an acute reference value at 
another exposure duration (e.g., 1 hour).
    Not all acute reference values are developed for the same purpose 
and care must be taken when interpreting the results of an acute 
assessment of human health effects relative to the reference value or 
values being exceeded. Where relevant to the estimated exposures, the 
lack of threshold values at different levels of severity should be 
factored into the risk characterization as potential uncertainties.
    Although every effort is made to identify peer-reviewed reference 
values for cancer and non-cancer effects for all pollutants emitted by 
the sources included in this assessment, some pollutants have no peer-
reviewed reference values for cancer or chronic non-cancer or acute 
effects. Since exposures to these pollutants cannot be included in a 
quantitative risk estimate, an understatement of risk for these 
pollutants at environmental exposure levels is possible.
    Additionally, chronic reference values for several of the compounds 
included in this assessment are currently under EPA IRIS review and 
revised assessments may determine that these pollutants are more or 
less potent than the current value. We may re-evaluate residual risks 
for the final rulemaking if, as a result of these reviews, a dose-
response metric changes enough to indicate that the risk assessment 
supporting this notice may significantly understate human health risk.
e. Uncertainties in the Multipathway and Environmental Effects 
Assessment
    We generally assume that when exposure levels are not anticipated 
to adversely affect human health, they also are not anticipated to 
adversely affect the environment. We generally rely on the facility-
specific levels of PB-HAP emissions to determine whether a full 
assessment of the multi-pathway and environmental effects is necessary. 
Because facility-specific PB-HAP emission levels were so far below 
levels which would trigger a refined assessment of multi-pathway 
impacts, we are confident that these types of impacts are insignificant 
for these source categories.
f. Uncertainties in the Facility-Wide Risk Assessment
    The same uncertainties discussed above exist with regard to the 
facility-wide risk assessments. Additionally, the degree of uncertainty 
associated with facility-wide emissions and risks is generally greater 
because we have not completed our review of emissions data for source 
categories not currently undergoing an RTR review.
g. Uncertainties in the Demographic Analysis
    Our analysis of the distribution of risks across various 
demographic groups is subject to the typical uncertainties associated 
with census data (e.g., errors in filling out and transcribing census 
forms), as well as the additional uncertainties associated with the 
extrapolation of census-block group data (e.g., income level and 
education level) down to the census block level.

B. How did we perform the technology review?

    Our technology review is focused on the identification and 
evaluation of ``developments in practices, processes, and control 
technologies.'' If a review of available information identifies such 
developments, then we conduct an analysis of the technical feasibility 
of requiring the implementation of these developments, along with the 
impacts (costs, emission reductions, risk reductions, etc.). We then 
make a decision on whether it is necessary to amend the regulation to 
require these developments.
    Based on specific knowledge of each source category, we began by 
identifying known developments in practices, processes, and control 
technologies. For the purpose of this exercise, we considered any of 
the following to be a ``development'':
     Any add-on control technology or other equipment that was 
not identified and considered during MACT development;
     Any improvements in add-on control technology or other 
equipment (that was identified and considered during MACT development) 
that could result in significant additional emission reduction;
     Any work practice or operational procedure that was not 
identified and considered during MACT development; and
     Any process change or pollution prevention alternative 
that could be broadly applied that was not identified and considered 
during MACT development.
    In addition to looking back at practices, processes, or control 
technologies reviewed at the time we developed the MACT standard, we 
reviewed a variety of sources of data to aid in our evaluation of 
whether there were additional practices, processes, or controls to 
consider. One of these sources of data was subsequent air toxics rules. 
Since the promulgation of the MACT standards for the source categories 
addressed in this proposal, EPA has developed air toxics regulations 
for a number of additional source categories. In these subsequent air 
toxic regulatory actions, we consistently evaluated any new practices, 
processes, and control technologies. We reviewed the regulatory 
requirements and/or technical analyses associated with these subsequent 
regulatory actions to identify any practices, processes, and control 
technologies considered in these efforts that could possibly be applied 
to emission sources in the source categories under this current RTR 
review.
    We also consulted EPA's RACT/BACT/LAER Clearinghouse (RBLC). The 
terms ``RACT,'' ``BACT,'' and ``LAER'' are acronyms for different 
program requirements under the CAA provisions addressing the national 
ambient air quality standards. Control technologies, classified as RACT 
(Reasonably Available Control Technology), BACT (Best Available Control 
Technology), or LAER (Lowest Achievable Emission Rate) apply to 
stationary sources depending on whether the sources are existing or 
new, and on the size, age, and location of the facility. BACT and

[[Page 65084]]

LAER (and sometimes RACT) are determined on a case-by-case basis, 
usually by State or local permitting agencies. EPA established the RBLC 
to provide a central data base of air pollution technology information 
(including technologies required in source-specific permits) to promote 
the sharing of information among permitting agencies and to aid in 
identifying future possible control technology options that might apply 
broadly to numerous sources within a category or apply only on a 
source-by-source basis. The RBLC contains over 5,000 air pollution 
control permit determinations that can help identify appropriate 
technologies to mitigate many air pollutant emission streams. We 
searched this database to determine whether any practices, processes, 
or control technologies are included for the types of processes used 
for emission sources (e.g., tanks or vents) in the source categories 
under consideration in this proposal.
    We also requested information from industry regarding developments 
in practices, processes, or control technology. Finally, we reviewed 
other information sources, such as State or local permitting agency 
databases and industry-supported databases.

C. How did we perform the analyses for the other actions being 
proposed?

    For several of the source categories considered in this proposal, 
we identified significant emission points that were not previously 
regulated under MACT. For these emission points, consistent with the 
requirements of CAA sections 112(d)(2) and (3), we identified the MACT 
floor for existing and new sources and considered beyond-the-floor 
options.
    We also reviewed the SSM provisions of each of the six MACT 
standards in light of Sierra Club v. EPA, 551 F.3d 1019. As part of 
this review, we evaluated available information and engaged industry 
concerning the type of activities and emissions that occur during 
periods of startup or shutdown.
    Finally, we identified potential revisions to these MACT standards 
to correct or clarify regulatory requirements. In the years since 
promulgation and compliance with the MACT standards, EPA has received 
comments and suggestions for improving the clarity of the MACT 
standards in general, as well as rule-specific comments for some 
individual MACT standards. These comments include such things as 
identification of editorial errors in the rule, clarification of 
existing rule text, regulatory obstacles to effective implementation of 
or compliance with the rule provisions. EPA has also independently 
identified these types of issues. We are proposing rule changes where 
appropriate.

V. Analyses Results and Proposed Decisions

    This section of the preamble provides background information on the 
MACT standards and source categories, the results of our RTR for each 
source category, our proposed actions to address significant 
unregulated emission points for a number of source categories, our 
proposed decisions concerning the SSM provisions in each of the six 
MACT standards, and the specific clarifications we are proposing for 
selected MACT standards.

A. What are the results and proposed decisions for the Chromium 
Electroplating source categories?

1. Overview of the Source Categories and MACT Standard
    National Emission Standards for Chromium Emissions from Hard and 
Decorative Chromium Electroplating and Chromium Anodizing Tanks 
(Chromium Electroplating MACT standards) were promulgated on January 
25, 1995 (60 FR 4963), and codified at 40 CFR part 63, subpart N. The 
Chromium Electroplating MACT standards regulate emissions of chromium 
compounds from three related source categories: Hard Chromium 
Electroplating, Decorative Chromium Electroplating, and Chromium 
Anodizing. Within these source categories, the MACT standards apply to 
all plants, both major and area sources, regardless of size.
    The Hard Chromium Electroplating source category consists of 
facilities that plate base metals with a relatively thick layer of 
chromium using an electrolytic process. Hard chromium electroplating 
provides a finish that is resistant to wear, abrasion, heat, and 
corrosion. These facilities plate large cylinders and industrial rolls 
used in construction equipment and printing presses, hydraulic 
cylinders and rods, zinc die castings, plastic molds, engine 
components, and marine hardware.
    The Decorative Chromium Electroplating source category consists of 
facilities that plate base materials such as brass, steel, aluminum, or 
plastic with layers of copper and nickel, followed by a relatively thin 
layer of chromium to provide a bright, tarnish- and wear-resistant 
surface. Decorative chromium electroplating is used for items such as 
automotive trim, metal furniture, bicycles, hand tools, and plumbing 
fixtures.
    The Chromium Anodizing source category consists of facilities that 
use chromic acid to form an oxide layer on aluminum to provide 
resistance to corrosion. The chromium anodizing process is used to coat 
aircraft parts (such as wings and landing gears), as well as 
architectural structures that are subject to high stress and corrosive 
conditions.
    The HAP emission sources subject to the Chromium Electroplating 
NESHAP are the tanks in which the chromium deposition takes place. For 
hard chromium and decorative chromium electroplating facilities, the 
emission sources are electroplating tanks. For the Chromium Anodizing 
source category, the emission sources are anodizing tanks.
    The primary emission controls used by the facilities in these 
source categories include packed bed scrubbers, mesh pad mist 
eliminators, composite mesh pad (CMP) systems, high efficiency 
particulate air (HEPA) filters, and wetting agent/fume suppressants 
(WAFS). Most decorative chromium electroplating plants comply with the 
MACT standards by using WAFS in the tank bath to control surface 
tension, which in turn reduces emissions. Some plants use a combination 
of WAFS and add-on control to meet the MACT emission limits. If a 
facility controls emissions using an add-on control device, the tank is 
generally equipped with a hood and duct work to exhaust emissions 
through the control device and out the stack. However, when WAFS are 
used as the only means of emission control, the tanks often are not 
equipped with exhaust hoods. In such cases, emissions from the tank are 
fugitive and are exhausted to the outside using wall-mounted exhaust 
fans.
    We estimate that there are approximately 1,770 plants that are 
currently subject to the Chromium Electroplating MACT standards. Of 
these, we estimate that there are 790 hard chromium electroplating 
plants, 740 decorative chromium electroplating plants, and 240 chromium 
anodizing plants. A detailed description of how the number of each type 
of plant was estimated can be found in the Estimated Number of Chromium 
Electroplating Plants document available in the docket for this action. 
Some facilities perform more than one type of chromium electroplating 
or anodizing. For purposes of our estimates, we classified facilities 
as hard chromium, decorative chromium, or chromium anodizing based on 
the primary type of electroplating operation performed at the facility. 
Some chromium

[[Page 65085]]

electroplating facilities electroplate items that are used internally 
in the manufacturing process at the same facility or within the same 
company. For example, some large printing facilities electroplate their 
printing rollers in house, and the chromium electroplating processes 
are located at the same site as the printing and publishing processes.
2. What data were used in our risk analyses?
    For the Chromium Electroplating source categories, we compiled a 
preliminary data set using data in the 2005 NEI. A review of the NEI 
resulted in the identification of data for 122 chromium electroplating 
facilities. These data were reviewed and the data for eight hard 
chromium and six decorative chromium electroplating plants were revised 
based on information in the facilities' permits or permit applications. 
Additional data were available for 44 facilities through responses to a 
CAA section 114 information request that was sent to facilities for the 
Plating and Polishing Area Source rule. The data for these facilities 
were added to the NEI data set, and, as with the original data, 
represent actual emission levels for these electroplating and anodizing 
facilities. Most of these facilities have low emissions, which are 
generally less than 2 pounds per year (lbs/yr). These 166 facilities 
now included in the 2005 NEI comprise approximately 9 percent of the 
estimated 1,770 facilities covered by the MACT standards, and include 
63 hard chromium electroplating, 96 decorative chromium electroplating, 
and 7 chromium anodizing facilities.\25\ This data set of 166 
facilities was modeled to determine the maximum individual cancer risk, 
the population cancer risk, the cancer incidence, and the maximum 
chronic non-cancer risk for the three source categories based on actual 
emissions. The maximum individual cancer risk and the maximum chronic 
non-cancer risk estimated from this data set were also compared to the 
maximum individual cancer risk and the maximum chronic non-cancer risk 
estimated from MACT-allowable emissions for the three source 
categories.\26\
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    \25\ The National Association of Surface Finishers provided OMB 
with data for 15 plants. We have placed this information in the 
docket for this rulemaking.
    \26\ The Occupational Safety and Health Administration adopted a 
lower permissible exposure limit for hexavalent chromium in 2006.
---------------------------------------------------------------------------

    To address the possibility that the small number of facilities 
included in the 166-facility data set might not be fully representative 
of the source categories and their risks, we developed an additional 
data set. In the development of this data set, we used ``model plants'' 
developed for the original MACT standard to represent the individual 
facilities. For hard and decorative chromium electroplating, we used 
three model plants (large, medium, and small) that represent average 
characteristics for each of these groups. For each of these plant 
sizes, there is an annual emissions rate (lbs/yr) that is derived from 
the design and operating parameters, and is specific to the size and 
type of model plant. For chromium anodizing, we have two model plants 
(large and small). The model plants were based on data collected during 
development of the original MACT standards from 1988 to 1993 from more 
than 100 facilities that responded to an Information Collection Request 
(ICR) for the chromium electroplating and anodizing industry. Data from 
site visits and other information also were used in developing the 
model plants. A complete description of the model plants developed for 
the MACT standard is provided in the Background Information Document 
(BID) for the original MACT standard (Chromium Electroplating BID).
    The basis for this additional data set is 1,629 chromium 
electroplating facilities with known addresses.\27\ For about half of 
these facilities, the type of electroplating performed is known, but 
the size of the facility is not known. For the remaining facilities, 
neither the type of chromium electroplating process or processes, nor 
the facility size is known.
---------------------------------------------------------------------------

    \27\ There is some overlap between the 1,629 facilities with 
known addresses and the 166 facilities for which we have emissions 
data based on the NEI and the data collection request.
---------------------------------------------------------------------------

    For use in the risk analysis, the limited available data were used 
to divide these facilities into six groups. Facilities in three of the 
six groups were assigned to be hard chromium electroplating facilities. 
Those groups include: hard chromium facilities; facilities with 
combined hard chromium operations and other electroplating or 
anodizing; and facilities with unknown processes. Together, these three 
groups yielded a total of 1,219 plants, all of which we modeled as hard 
chromium electroplating facilities. This total, in addition to the 63 
hard chromium electroplating facilities in the 2005 NEI data set, 
yields a total of 1,282 facilities, which is substantially higher than 
the 790 hard chromium facilities that we estimate exist in the United 
States. However, because hard chromium facilities have the highest 
emissions among the three source categories, we made these selections 
as a conservative or health-protective assumption.
    To represent the decorative chromium electroplating facilities, we 
combined two of the six groups of facilities; decorative chromium 
facilities and facilities that perform both decorative chromium and 
chromium anodizing. This results in 319 decorative chromium facilities 
in this data set, which, even when combined with the 96 decorative 
chromium electroplating facilities in the 2005 NEI data set, is less 
than the 740 facilities that we believe exist in the industry. Because 
we modeled all of the unknown electroplating type facilities as the 
highest-emitting hard chromium electroplating facilities, we consider 
this assessment to be conservative, even though it appears to under-
represent decorative chromium facilities.
    Similarly, the last of the six groups are all known chromium 
anodizing facilities. This group includes 73 facilities, and, when 
combined with the 7 chromium anodizing facilities in the 2005 NEI data 
set, still represents only about a third of the 240 facilities chromium 
anodizing facilities. Again, we believe this is conservative because 
those facilities not modeled as chromium anodizing plants were modeled 
as the higher emitting hard chromium facilities in the analysis.
    To estimate the risks for this assessment, we needed to establish 
estimated emissions for each of the electroplating and anodizing types. 
To ensure that we did not underestimate cancer risk to the most exposed 
individual, we originally planned to use the large plant emission 
factors that we had developed for the original MACT standard to 
represent all model plants for each type of chromium electroplating 
processing. In reviewing available emissions data, we found that, while 
the large plant emission factors adequately represent the average 
chromium emissions from known large decorative chromium electroplating 
and large chromium anodizing facilities, they are not representative of 
the average chromium emissions from large hard chromium electroplating 
facilities.
    The emission factor for large hard chromium electroplating 
developed for the original MACT standard was 35.3 lbs/yr. However, in 
comparing this emission factor to available emissions data for 
individual facilities, we find that this emissions factor is 
unrealistically high and does not represent the average level of 
emissions for large facilities as we would expect to see under the 
current MACT standard. As explained more fully in the Model Plant Data 
Used to Estimate Risk from

[[Page 65086]]

Chromium Electroplating Sources document available in the docket for 
this action, based on the large model plant design flow rate and 
operating hours, a large hard chromium model plant operating at the 
MACT emission limit of 0.015 milligrams per dry standard cubic meter 
(mg/dscm) would emit a maximum of only 23.6 lbs/yr of chromium 
compounds. Moreover, the available data on actual emissions for hard 
chromium electroplating plants indicate there are only 4 plants with 
annual emissions greater than 10 lbs/yr. As a result, we determined 
that the large size model plant emissions factor, as defined for the 
original MACT standard, is not representative of existing large hard 
chromium electroplating facilities on a nationwide basis. On the other 
hand, the emission factor associated with a medium size hard chromium 
electroplating model plant (9.26 lbs/yr) falls between the 90th 
percentile (8.04 lbs/yr) and the 95th percentile (11.6 lbs/yr) of the 
available emissions data for hard chromium electroplating facilities. 
Because this emission factor, which was originally developed for medium 
sized facilities at the time the MACT standard was developed, is 
representative of the emissions from large facilities, the emissions 
factor of 9.26 lbs/yr was used to represent current large hard chromium 
electroplating facilities. Thus, for purposes of this residual risk 
review, we refer to 9.26 lbs/yr as the emissions factor for a ``large'' 
hard chromium electroplating facility.
    We believe the approach of using the ``large'' facility emissions 
factor to represent all facility sizes is reasonable to ensure that we 
did not underestimate maximum individual cancer risk. Although we 
believe that only a small percentage of the facilities are large, we 
recognize that we do not have emissions data for approximately 90 
percent of the sources. Thus, by assuming all sources are large, we 
have ensured that we will not underestimate the maximum individual 
risk.
    For hard chromium electroplating, the model plant emission factors 
for small, medium, and large facilities range from 0.55 to 9.26 lbs/yr. 
While we expect only 10 percent of the facilities to be large, based on 
the distribution of model plant sizes developed for the MACT standard, 
we used the emissions factor for a large facility (9.26 lbs/yr) for all 
of the 1,219 facilities that we considered as hard chromium 
electroplating facilities. Similarly, for decorative chromium 
electroplating, the emission factors for small, medium, and large 
facilities are 0.065, 0.27, and 2.65 lbs/yr, respectively, and the 
large facility emissions factor was used in the risk assessment for 
decorative chromium. For the Decorative Chromium category, we estimate 
that only 5 percent of the facilities are large, based upon the 
distribution of decorative chromium plants nationwide when the original 
NESHAP were developed. Finally, for chromium anodizing, the emission 
factor for small facilities is 0.036 lb/yr, and for large facilities, 
is 0.44 lb/yr. The large facility emissions factor (0.44 lb/yr) was 
used in the conservative analysis for all of the anodizing facilities 
even though we estimate that only 25 percent are large.
    Population risk indicators can be greatly overstated when highly 
conservative emission estimates are applied to every facility in the 
source category. Recognizing this fact, we performed a supplemental 
analysis to better address nationwide average emission levels and 
assess the sensitivity of our population risk estimates. Thus, as 
described further below, the supplemental analysis was performed to 
understand the degree to which the risk might be overstated, and, thus, 
how much weight to attach to the conservative analysis. The 
conservatism of this risk assessment is one factor that we consider in 
determining whether the risk is acceptable within the meaning of the 
Benzene NESHAP.
    For the supplemental analysis, we assigned unique emission factors 
to each of the 6 groups of facilities in our 1,629 facility data set. 
These emission factors were developed to better estimate the average 
emissions for all of the sources within each group. The new emission 
factors are:
     2.24 lbs/yr for known hard chromium electroplating 
facilities,
     0.225 lb/yr for known decorative chromium electroplating 
facilities,
     0.137 lb/yr for known chromium anodizing facilities,
     1.23 lbs/yr for facilities with combinations of hard 
chromium electroplating and either decorative electroplating or 
anodizing,
     0.181 lb/yr for facilities with combinations of decorative 
electroplating and anodizing, and
     1.11 lbs/yr for facilities where the type of process 
(electroplating or anodizing) is unknown.
    A detailed explanation for how these emission factors were derived 
can be found in the Model Plant Data Used to Estimate Risk from 
Chromium Electroplating Sources available in the docket for this 
action. These weighted average emission factors account for the plant 
type (hard chromium electroplating, decorative chromium electroplating, 
or chromium anodizing) and the distribution of plant sizes (large, 
medium, or small). For example, the average emissions factor for hard 
chromium electroplating (2.24 lbs/yr) is the weighted average of the 
model plant emission factors for large plants (10 percent of plants at 
9.26 lbs/yr per plant), medium plants (20 percent of plants at 4.63 
lbs/yr per plant, and small plants (70 percent of plants at 0.55 lb/yr 
per plant). This distribution of plant sizes is based on actual data 
collected during development of the original MACT rule. We have no 
reason to believe the distribution of facility sizes has changed 
significantly since then.
    The uncertainties associated with both the conservative analysis 
and the supplemental analysis include the estimated distribution of 
plant types and sizes as well as the facility emissions factors. 
Although the type of plants used in the NEI analysis is based on a 
variety of reliable sources, including ICR responses for the Plating 
and Polishing NESHAP, trade association data, data from State agencies, 
and information from Web sites, we were unable to identify the plant 
type for nearly half of the data set. For those plants of unknown type, 
we used the highest emissions factor, which corresponds to a large hard 
chromium plant, in the conservative analysis. For the supplemental 
analysis, we developed an emissions factor using a weighted average 
across all plant types and sizes. For all plants that were modeled, we 
are soliciting additional information on actual and MACT-allowable 
emissions, plant type, and plant size. More information about the 
development of the model plants can be found in the Model Plant Data 
Used to Estimate Risk from Chromium Electroplating Sources document 
available in the docket for this action.
    In all the data sets, chromium compounds account for all the HAP 
emissions from the Chromium Electroplating and Chromium Anodizing 
source categories. For the Hard Chromium Electroplating source 
category, in the NEI-based data set, chromium VI compounds account for 
98 percent of the emissions, with chromium III and chromium trioxide 
compounds comprising the remaining HAP. In both the NEI and model plant 
emission estimates, we made the conservative assumption that 100 
percent of the emissions are chromium VI compounds. For the Decorative 
Chromium Electroplating source category, in the NEI-based data set, 
chromium VI compounds account for 94 percent of the emissions, with 
chromium III and chromium trioxide compounds comprising the remaining 
HAP. In both emission estimates, we

[[Page 65087]]

made the conservative assumption that 100 percent of the emissions are 
chromium VI compounds. For the Chromium Anodizing source category, in 
the NEI-based data set, chromium VI compounds account for 99 percent of 
the emissions with chromium III compounds comprising the remaining HAP. 
In both emission estimates, we made the conservative assumption that 
100 percent of the emissions are chromium VI compounds.
3. What are the results of the risk assessments and analyses?
    We conducted an inhalation risk assessment for each of the three 
source categories: Hard Chromium Electroplating, Decorative Chromium 
Electroplating, and Chromium Anodizing. Also, for each source category, 
we conducted an assessment of facility-wide risk, and performed a 
demographic analysis of population risks. As noted above, we developed 
two data sets for these source categories, one based primarily on NEI 
data for 166 sources, and one based on model plant data for 1,629 
sources.
    The following tables present the combined results from the data 
sets. Table A.1 provides an overall summary of the maximum individual 
inhalation risk assessment results, and Table A.2 provides population 
risk assessment results for the Hard Chromium Electroplating, 
Decorative Chromium Electroplating, and Chromium Anodizing source 
categories.

                         Table A.1--Chromium Electroplating and Anodizing Maximum Individual Inhalation Risk Assessment Results*
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                             Maximum individual     Maximum chronic non-cancer
                                                              cancer risk (in 1              TOSHI \3\
                                              Number of         million) \2\       ----------------------------
              Source category                 facilities --------------------------                             Maximum off-site acute non-cancer HQ \4\
                                              (NEI/model     Actual     Allowable      Actual       Allowable
                                              plant) \1\   emissions    emissions     emissions     emissions
                                                             level        level         level         level
--------------------------------------------------------------------------------------------------------------------------------------------------------
Hard Chromium Electroplating...............     63/1,219           70           90         0.06          0.09   Not applicable \5\.
Decorative Chromium Electroplating.........       96/337           70           70         0.06          0.06   Not applicable \5\.
Chromium Anodizing.........................         7/73            5            5         0.004         0.004  Not applicable \5\.
--------------------------------------------------------------------------------------------------------------------------------------------------------
* All results are for impacts out to 50 km from each source in the categories.
\1\ Number of facilities evaluated in the risk analysis: the first number refers to the NEI data set, and the second number applies to the conservative
  emission estimate.
\2\ Maximum individual excess lifetime cancer risk.
\3\ Maximum TOSHI. The target organ with the highest TOSHI for the Hard Chromium Electroplating, Decorative Chromium Electroplating, and Chromium
  Anodizing source categories 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 threshold. See section IV.A. of this preamble for explanation of acute threshold values.
\5\ NA = not applicable. There are no HAP with acute dose-response benchmark values, so no acute HQ were calculated for these source categories. See
  section IV.A of this preamble for an explanation of acute threshold values.

                           Table A.2--Chromium Electroplating and Anodizing Population Risk Inhalation Risk Assessment Results
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                              Conservative assessment      Conservative       Supplemental assessment      Supplemental
                                             Number of          population at risk         annual cancer        population at risk         annual cancer
             Source category                facilities   --------------------------------    incidence   --------------------------------    incidence
                                            (NEI/model       >= 1-in-1      >= 10-in-1      (cases per       >= 1-in-1      >= 10-in-1       (case per
                                              plant)          million         million          year)          million         million          year)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Hard Chromium Electroplating............        63/1,219      14,200,000          71,000           0.8           360,000           5,100           0.1
Decorative Chromium Electroplating......          96/337         390,000           4,000           0.08           30,000           1,300           0.01
Chromium Anodizing......................            7/73           2,700               0           0.003             540               0           0.001
--------------------------------------------------------------------------------------------------------------------------------------------------------

    As shown in Table A.1, the results of the inhalation risk 
assessment for the Hard Chromium Electroplating source category 
indicate the maximum lifetime individual cancer risk could be as high 
as 70-in-1 million, based on actual emissions, and as high as 90-in-1 
million based on allowable emissions. This maximum individual cancer 
risk is based on the highest risk facility out of the 63 actual 
facilities and the 1,219 model plants. The highest risk facility is one 
for which we have design and operating data, and we believe it is also 
both the largest and highest emitting hard chromium electroplating 
facility in the United States. Thus, we believe this level accurately 
reflects the maximum individual exposure. The maximum chronic non-
cancer TOSHI value could be 0.06, based on the actual emissions level, 
and up to 0.09 based on allowables. This value is also based on known 
emission levels from the largest facility in the nation. A non-cancer 
TOSHI of one or less is not of human health concern.
    The total estimated national cancer incidence from hard chromium 
electroplating facilities based on actual emission levels is 0.8 excess 
cancer cases per year, or one case in every 1.25 years for the 
conservative assessment. Our risk assessment shows 14.2 million people 
exposed to a cancer risk greater than 1-in-1 million and 71,000 people 
exposed to a cancer risk of at least 10-in-1 million.
    As noted above, we conducted a supplemental analysis to determine 
the weight to give to the conservative risk analysis. That supplemental 
analysis estimates 0.1 excess cancer cases per year, or one case in 
every 10 years. Additionally, it estimates a population exposure of 
360,000 people at 1-in-1 million cancer risk. For a cancer risk of at 
least 10-in-1 million, the population exposed decreases to 5,100.
    Based on the 2005 NEI data set for the Decorative Chromium 
Electroplating

[[Page 65088]]

source category, the maximum lifetime individual cancer risk could be 
as high as 70-in-1 million, and the maximum chronic non-cancer TOSHI 
value could be up to 0.06, based on the actual emissions level.\28\ We 
do not believe the maximum lifetime individual cancer risk and the 
maximum chronic non-cancer TOSHI value would be any higher than this 
based on allowable emissions. The total estimated population risks from 
the conservative risk assessment of the decorative chromium 
electroplating facilities based on actual emission levels is 390,000 
people exposed to a cancer risk greater than 1-in-1 million and 0.08 
excess cancer cases per year, or one case in every 12 years.\29\
---------------------------------------------------------------------------

    \28\ There is uncertainty regarding the operating status of the 
facility (reported to be closed) associated with the maximum 
lifetime individual cancer risk. Prior to any final rulemaking 
action, we will investigate this situation and revise the risk 
analysis and results accordingly.
    \29\ Based on our conservative risk assessment, we believe the 
risks are low, and, as explained further below, are proposing that 
the risks are acceptable for the Decorative Chromium source 
category. Although we did not need to consider the supplemental 
analysis that we conducted for Decorative Chromium to help guide our 
conclusion about the uncertainty of the risk assessment results, we 
note that the supplemental assessment shows 30,000 people exposed to 
a cancer risk greater than 1-in-1 million and 0.01 excess cancer 
case per year, or one case in every 100 years.
---------------------------------------------------------------------------

    Based on the 2005 NEI data set for the Chromium Anodizing source 
category, the maximum lifetime individual cancer risk could be as high 
as 5-in-1 million and the maximum chronic non-cancer TOSHI value could 
be up to 0.004, based on the actual emissions level. The total 
estimated population risks from the conservative assessment of the 
chromium anodizing facilities based on actual emission levels is 2,700 
people exposed to a cancer risk greater than 1-in-1 million and 0.003 
excess cancer cases per year, or one case in every 333 years.\30\
---------------------------------------------------------------------------

    \30\ Based on our conservative risk assessment, we believe the 
risks are low, and, as explained further below, are proposing that 
the risks are acceptable for the Chromium Anodizing source category. 
Although we did not need to consider the supplemental analysis that 
we conducted for Chromium Anodizing to help guide our conclusion 
about the uncertainty of the risk assessment results, we note that 
the supplemental assessment shows 540 people exposed to a cancer 
risk greater than 1-in-1 million and 0.001 excess cancer case per 
year, or one case in every 1,000 years.
---------------------------------------------------------------------------

    Also, as there were no reported emissions of PB-HAP for these three 
source categories, we do not expect the potential for human health 
multipathway risks or adverse environmental impacts.
    Our analyses of potential differences between actual emission 
levels and emissions allowable under the MACT standards are based on 
emissions test data from specific facilities. A comparison of these 
test results to allowable emissions at these facilities indicates that 
the ratio of MACT-allowable to actual emissions varies considerably 
from facility to facility. As a result, a uniform factor was not 
available to apply to all facilities. However, for the Hard Chromium 
Electroplating source category, we did evaluate the facility that was 
modeled as having the highest maximum individual lifetime cancer risk 
(70-in-1 million) based on actual emissions. Our analysis indicates 
that this facility, if operated at the allowable emissions limit, could 
have a maximum individual lifetime cancer risk as high as 90-in-1 
million. Furthermore, the available data indicate that no other hard 
chromium electroplating facility would have a cancer risk that high if 
operated at the allowable emissions limit.
    For the Decorative Chromium Electroplating source category, we 
performed a similar analysis of the available data and concluded that 
the maximum individual lifetime cancer risk would not exceed 70-in-1 
million for any facility that operated at the allowable emissions 
limit. As stated earlier, because most chromium anodizing facilities 
use WAFS, we believe actual emissions are essentially the same as 
allowable emissions. Thus, we believe that the MIR based on allowable 
emissions would be the same as that based on actual emissions, i.e., 5-
in-1 million.
    Table A.3 displays the results of the facility-wide risk assessment 
for actual emissions of all sources at the facility as reported in the 
NEI. We did not perform a facility-wide risk assessment based on 
allowable emissions, as explained in the documentation referenced in 
section IV.A of this preamble, which is available in the docket for 
this action.

             Table A.3--Chromium Electroplating and Anodizing Facility-Wide Risk Assessment Results
----------------------------------------------------------------------------------------------------------------
                                                                     Source                           Source
                                                                    category                         category
                                                     Maximum      contribution                     contribution
                                                  facility-wide      to this         Maximum          to this
                Source category                    individual        maximum      facility-wide       maximum
                                                   cancer risk    facility-wide    chronic non-    facility-wide
                                                 (in 1 million)    individual      cancer TOSHI    chronic non-
                                                                   cancer risk                     cancer TOSHI
                                                                       \1\                              \1\
----------------------------------------------------------------------------------------------------------------
Hard Chromium Electroplating...................              90            < 1%              2              < 1%
Decorative Chromium Electroplating.............              90              7%              0.8            < 1%
Chromium Anodizing.............................              20             75%              0.2            < 1%
----------------------------------------------------------------------------------------------------------------
\1\ Percentage shown reflects source category contribution to the maximum facility-wide risks at the facility
  with the maximum risk value shown.

    As shown in Table A.3, the maximum individual cancer risks from all 
HAP emissions at facilities that perform hard chromium electroplating, 
decorative chromium electroplating, and chromium anodizing are 
estimated to be 90-in-1 million, 90-in-1 million, and 20-in-1 million, 
respectively. For the facilities where these maximum risk values occur, 
the estimated proportion of the cancer risk attributable to the hard 
chromium electroplating, decorative chromium electroplating, and 
chromium anodizing processes is less than 1 percent, 7 percent, and 75 
percent, respectively. The highest facility-wide cancer risk for a 
facility that includes a hard chromium electroplating source is 
primarily driven by chemical production processes. We are currently 
developing a chemical manufacturing sector project \31\ and plan to 
address risk from these chemical production processes as part of that 
action. The highest facility-wide cancer risk for a facility that 
includes a decorative chromium electroplating

[[Page 65089]]

source is primarily driven by aerospace processes that will be 
addressed in a future residual risk review for the Aerospace 
Manufacturing and Rework Facilities source category. The highest 
facility-wide cancer risk for a facility that includes a chromium 
anodizing source is primarily driven by the chromium anodizing 
processes. The facility-wide maximum chronic non-cancer TOSHI values 
for facilities that include Hard Chromium Electroplating, Decorative 
Chromium Electroplating, and Chromium Anodizing source category 
processes are estimated to be 2, 0.8, and 0.2, respectively. At the 
facilities where these maximum risk values occur, the estimated 
proportion of the non-cancer risk attributable to the Hard Chromium 
Electroplating, Decorative Chromium Electroplating, and Chromium 
Anodizing source category processes is less than 1 percent for each 
source category.
---------------------------------------------------------------------------

    \31\ This is one of several projects EPA is undertaking to 
establish and implement national emission-control measures for 
specific sectors of the economy by taking an integrated 
multipollutant approach to assessing and implementing additional 
emission controls using our existing regulatory frameworks.
---------------------------------------------------------------------------

    The results of the demographic analyses performed to investigate 
the distribution of risks above 1-in-1 million, based on actual 
emissions levels for the population living within 5 km of the 
facilities, among various demographic groups are provided in a report 
available in the docket for this action and summarized in Tables A.4, 
A.5, and A.6 below. These estimates of total population with risk 
exceeding 1-in-1 million differ from the risk estimates presented above 
because the demographic analysis uses a 5 km radius and the risk 
assessment results provided above reflect use of a 50 km radius around 
all chromium electroplating facilities.

                                         Table A.4--Hard Chrome Electroplating Demographic Risk Analysis Results
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                             Population with risk greater than 1-in-1 million
                                       Maximum   -------------------------------------------------------------------------------------------------------
          Emissions basis            risk  (in 1                                          Other and                              Below the   Over 25  w/
                                       million)      Total     Minority  %    African    multiracial  Hispanic or     Native      poverty      o a  HS
                                                   (millions)                American %       %         Latino %    American %    level %     diploma %
--------------------------------------------------------------------------------------------------------------------------------------------------------
Nationwide.........................          n/a          285           25           12           12           14          0.9           13           13
Source Category....................           70         13.1           52           23           29           34          0.6           22           20
Facility-wide......................           90         13.1           52           23           29           34          0.6           22           20
--------------------------------------------------------------------------------------------------------------------------------------------------------

                                     Table A.5--Decorative Chromium Electroplating Demographic Risk Analysis Results
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                             Population with risk greater than 1-in-1 million
                                       Maximum   -------------------------------------------------------------------------------------------------------
          Emissions basis            risk  (in 1                                          Other and                              Below the   Over 25  w/
                                       million)      Total      Minority %    African    multiracial  Hispanic or     Native      poverty      o a  HS
                                                   (millions)                American %       %         Latino %    American %    level %     diploma %
--------------------------------------------------------------------------------------------------------------------------------------------------------
Nationwide.........................          n/a          285           25           12           12           14          0.9           13           13
Source Category....................           70         0.35           50           18           32           47          0.8           24           23
Facility-wide......................           90         0.43           54           21           32           48          0.7           24           25
--------------------------------------------------------------------------------------------------------------------------------------------------------

                                             Table A.6--Chromium Anodizing Demographic Risk Analysis Results
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                             Population with risk greater than 1-in-1 million
                                       Maximum   -------------------------------------------------------------------------------------------------------
          Emissions basis            risk  (in 1                                          Other and                              Below the   Over 25  w/
                                       million)      Total      Minority %    African    multiracial  Hispanic or     Native      poverty      o a  HS
                                                   (millions)                American %       %         Latino %    American %    level %     diploma %
--------------------------------------------------------------------------------------------------------------------------------------------------------
Nationwide.........................          n/a          285           25           12           12           14          0.9           13           13
Source Category....................            5       0.0027           36           16            0            0          0.4           25           19
Facility-wide......................           20       0.0079           22           10           12           13          0.8           19           16
--------------------------------------------------------------------------------------------------------------------------------------------------------

    The results of the demographic analysis show that, for the 
population located within 5 km of Hard Chromium Electroplating source 
category, there are about 13.1 million people with cancer risks greater 
than 1-in-1 million for both the source category and facility-wide. Of 
this population at risk, 52 percent could be classified as a 
``Minority,'' 34 percent are included in the ``Hispanic or Latino'' 
demographic group, 29 percent are included in the ``Other and 
Multiracial'' demographic group, 23 percent are included in the 
``African-American'' demographic group, 22 percent are included in the 
``Below Poverty Level'' demographic group, and 20 percent are included 
in the ``Over 25 Without a High School Diploma'' demographic group. The 
percentage of the population within 5 km of a hard chromium 
electroplating facility and with a cancer risk greater than 1-in-1 
million is higher than the typical distribution of these demographic 
groups across the United States. These demographic analyses are based 
on the conservative assessment results.
    For the Decorative Chromium Electroplating source category, there 
are about 350,000 people with cancer risks greater than 1-in-1 million 
for the source category and 430,000 people with

[[Page 65090]]

cancer risks greater than 1-in-1 million facility-wide. Of this 
population at risk, 50 percent could be classified as a ``Minority,'' 
47 percent are included in the ``Hispanic or Latino'' demographic 
group, 32 percent are included in the ``Other and Multiracial,'' 
demographic group, 18 percent are included in the ``African-American'' 
demographic group, 24 percent are included in the ``Below Poverty 
Level'' demographic group, and 23 percent are included in the ``Over 25 
Without a High School Diploma'' demographic group. The percentage of 
the population within 5 km of a decorative chromium electroplating 
facility and with a cancer risks greater than 1-in-1 million is higher 
than the typical distribution of these demographic groups across the 
United States. The results of the demographic analysis for facility-
wide emissions are similar to the results for the source category.
    For the Chromium Anodizing source category, there are about 2,700 
people with cancer risks greater than 1-in-1 million and 7,900 people 
with cancer risks greater than 1-in-1 million facility-wide. Of the 
population with cancer risks greater than 1-in-1 million, 36 percent 
could be classified as a ``Minority,'' 16 percent are included in the 
``African-American'' demographic group, 25 percent are included in the 
``Below Poverty Level'' demographic group, and 19 percent are included 
in the ``Over 25 Without a High School Diploma'' demographic group. The 
percentage of the population within 5 km of a chromium anodizing 
facility and with a cancer risk greater than 1-in-1 million is higher 
than the typical distribution of these demographic groups across the 
United States. The results of the facility-wide demographic analysis 
are higher than the typical distribution of risks to the demographic 
groups across the United States, for the ``Below Poverty Level'' and 
the ``Over 25 Without a High School Diploma'' demographic groups, but 
are lower than these levels for the other demographic groups.
    Details of these assessments and analyses can be found in the 
residual risk documentation as referenced in section IV.A of this 
preamble, which is available in the docket for this action.
4. What are our proposed decisions on risk acceptability and ample 
margin of safety?
a. Risk Acceptability
    The risk analysis we performed for this proposal indicates that for 
the Hard Chromium Electroplating source category, the cancer risks to 
the individual most exposed is 70-in-1 million based on actual 
emissions and 90-in-1 million based on MACT-allowable emissions. The 
maximum non-cancer risk level, which is low, is a TOSHI of 0.06 based 
on actual emissions and 0.09 based on allowable emissions. These risks 
are due to estimated emissions of hexavalent chromium, which EPA 
describes as a known human carcinogen by the inhalation route of 
exposure. As explained above, both the MIR and the maximum non-cancer 
risk levels are based on emissions from what we believe is the highest 
risk hard chromium facility operating in the United States.
    We further estimate that the excess cancer incidence could be as 
high as 0.8 cases per year, and that over 14 million people could be 
exposed to a cancer risk of 1-in-1 million or greater. These risk 
levels are based on a highly conservative risk assessment as described 
above. In summary, in this assessment we used (1) actual emissions data 
for 63 facilities and (2) emissions estimates that are reflective of 
average emissions for the highest emitting facilities for each one of 
an additional 1,219 facilities not in the original dataset. Because 
there are only 790 hard chromium facilities, and because only ten 
percent of the facilities would have this high an emissions rate, we 
believe that these conservative risk assessment results overstate 
cancer incidence and population exposure.
    As noted above, we performed a supplemental analysis to assess the 
degree to which the conservative risk assessment may overstate risks, 
and, thus, to determine how heavily to weigh those risks in determining 
whether to find the risks acceptable. In this supplemental analysis we 
assessed these risks based on (1) the emissions data used in the 
conservative assessment for the 63 facilities for which we have actual 
facility emission information, and (2) revised emission data that 
better represent nationwide average emission levels for the 1,219 
facilities. The supplemental assessment indicates that the excess 
cancer risks from hard chromium electroplating facilities is 0.1 cancer 
cases per year and 360,000 people exposed to a cancer risk of 1-in-1 
million or more, which is substantially less than we found with the 
conservative assessment. These results indicate that the estimated 
risks are uncertain and are highly sensitive to input assumptions and 
that the conservative assessment may substantially overstate risks.
    The results of our demographic analysis indicate that minorities 
face disproportionate risks \32\ from exposure to emissions from this 
category (Tables A.4-A.6). Although the demographic analysis was based 
on our conservative risk assessment modeling, we have no reason to 
believe that the results would be substantially different were we to 
re-run that analysis using the assumptions underlying the supplemental 
assessment. This is because the disparate impacts identified through 
our demographic analysis are reflective of the fact that many chrome 
facilities are located in inner city urban areas, and in or near 
residential neighborhoods more likely to be inhabited by minority and 
low income persons. We are concerned about the potential 
disproportionate health risks from these urban facilities on minorities 
and those below the poverty level. We solicit comment on whether there 
may be pollution prevention efforts or other HAP emission reduction 
approaches that could mitigate the impacts that these facilities have 
on their immediate surroundings. We also recognize that, in addition to 
whatever controls are required in the final rulemaking for the Hard 
Chromium Electroplating source category, there may be other approaches, 
such as facility-specific compliance assistance, that could mitigate 
the impacts that these facilities have on their immediate surroundings. 
We solicit comment and supporting information to assist EPA in 
identifying measures to mitigate these disproportionate risks.
---------------------------------------------------------------------------

    \32\ Using census data on race and ethnicity, we estimated the 
percentage of people in the United States that are minority. We also 
estimated the percentage of people that live within 5 km of each 
facility and have cancer risks greater than 1-in-1 million that are 
minority. Where the percentage of people at risk is higher than the 
percentage nationwide, those minorities face disproportionate risks.
---------------------------------------------------------------------------

    In accordance with the approach established in the Benzene NESHAP, 
EPA weighed all health risk measures and information, including the 
maximum individual cancer risk, the cancer incidence, the number of 
people exposed to a risk greater than 1-in-1 million, the distribution 
of risks in the exposed population, and the uncertainty of our risk 
calculations in determining whether the risk posed by emissions from 
hard chromium facilities is acceptable.
    As an initial matter, we note that the 90-in-1 million risk based 
on allowable emissions is approaching the ``presumptive limit on 
maximum individual lifetime risk of approximately 1-in-10 thousand 
[100-in-1 million]'' recognized in the Benzene NESHAP (54 FR 38045). We 
also note

[[Page 65091]]

that, based on our conservative analysis, there is a high level of 
cancer incidence of 0.8 excess cancer cases per year nationwide, and a 
very large number (14.2 million) of people potentially exposed to a 
cancer risk greater than 1-in-1 million.\33\ However, we also recognize 
that our supplemental assessment based on alternative input assumptions 
concerning emissions (that better represent nationwide average 
emissions) indicate that the results of the conservative assessments 
are substantially overstated. Thus, there is great uncertainty about 
both the cancer incidence and the number of people exposed.
---------------------------------------------------------------------------

    \33\ These comparisons refer to estimates of incidence and 
populations from risk assessments performed for other source 
categories previously covered by RTR risk assessments.
---------------------------------------------------------------------------

    On the one hand, we acknowledge that the cancer incidence and 
number of people exposed to cancer risks of 1-in-1 million or greater 
are high based on our conservative analysis. On the other hand, we 
recognize the significant uncertainty of these risk estimates and the 
likelihood that they are overstated, based on the conservative nature 
of the assessment. The supplemental analysis highlights the sensitivity 
of our risk analysis to highly uncertain input assumptions and supports 
a determination that the population exposure and cancer incidence risk 
numbers are overstated. It shows substantially lower cancer incidence 
(0.1 excess cases per year nationwide as opposed to 0.8) and number of 
people potentially exposed to a cancer risk of 1-in-1 million or more 
(360 thousand as opposed to 14.2 million). In addition, the 
distribution of risks in the exposed population shows the number of 
people exposed to a cancer risk greater than 10-in-1 million is 71,000 
for the conservative assessment and 5,100 for the supplemental 
analysis.
    In determining whether risk is acceptable, we focus on the results 
of all aspects of the risk assessment. Because the MIR is less than 
100-in-1 million, and because of the significant uncertainty of the 
cancer incidence and number of people exposed, which we believe are 
overstated based on the fact that our risk analysis was highly 
conservative, at this time, we are proposing that the risks from the 
Hard Chromium Electroplating source category are acceptable. We are 
proposing that the risks are acceptable, in large part, because we 
believe that the assumptions underlying the supplemental analysis may 
present a more realistic estimate of the emissions from hard chromium 
facilities.
    However, we are very concerned by the results of our conservative 
risk analysis, especially the large number of people (including 
disproportionately affected populations) estimated to be exposed at a 
cancer risk above 1-in-1 million. We are also concerned about the level 
of uncertainty with our analysis given that we have very limited 
information as to the number (and size) of the facilities. While our 
current proposal is supported by recognizing the uncertainty associated 
with the high risk levels from our conservative assessment and, as 
explained above, that uncertainty (as demonstrated by the supplemental 
analysis) points in the direction of an overstatement of risk, we would 
prefer to base a final rule on more complete and reliable information. 
The purpose of the residual risk standards under CAA section 112(f) is 
to ensure protection of public health and the environment. Thus, we 
believe it is important to develop a conservative risk analysis and err 
on the side of potential overestimation of risk analyses where we are 
missing data. In this case, we recognize that the assessment may be 
overly conservative, and we are considering additional methods for 
performing a conservative analysis. However, we believe additional 
information and data regarding the location, type and size of 
facilities will be important to performing any additional analysis that 
would err on the side of protectiveness without being overly 
conservative. At this time, we are not certain that we would take final 
action finding the risk to be acceptable based on the limited 
information currently available to the Agency.
    The comments and information that we receive on this proposal will 
be critical in making a final decision on acceptability. We are 
soliciting comment and data to help the Agency make an informed 
decision as it moves forward with this rulemaking. Specifically, with 
regard to each of the facilities listed in Appendix A to this preamble, 
we are seeking to identify (1) the actual annual emissions, if known; 
(2) which of the three source categories it falls within; and (3) 
whether, for hard chromium, it is a ``large'' or ``small'' facility 
within the definitions in 40 CFR 63.341(a). In particular, we are 
encouraging the States to provide EPA with better inventory data for 
sources within their States. Moreover, we are encouraging States to 
help identify sources that may be located near sensitive populations or 
other populations of concern, such as located near schools or that may 
be located in communities with a significant minority population. To 
feel comfortable with a final decision finding the risk acceptable, we 
believe it is important to reduce the level of uncertainty associated 
with our current analyses. Thus, in light of the comments and any 
additional data (or lack thereof) that we receive during the comment 
period, we may determine that it is appropriate to issue a supplemental 
proposal in which we propose to find the risk unacceptable. If we issue 
a supplemental proposal in which we propose to find the risk 
unacceptable, we would be required to propose emissions standards or 
work practices that reduce risk to a level that is acceptable and 
provides an ample margin of safety.
    For the Decorative Chromium Electroplating source category, the 
cancer risks to the individual most exposed is 70-in-1 million, based 
on both actual and MACT-allowable emissions. Based on this cancer risk 
level and in consideration of other health measures and factors, 
including the cancer incidence (one case in every 12.5 years) and the 
low maximum non-cancer risk level (TOSHI of 0.06 based on both actual 
and MACT-allowable emissions), we propose that the risks from the 
Decorative Chromium Electroplating source category are acceptable.
    For the Chromium Anodizing source category, the cancer risks to the 
individual most exposed is 5-in-1 million, based on both actual and 
allowable emissions. Based on this low cancer risk level and in 
consideration of other health measures and factors, including the 
cancer incidence (one case in every 250 years) and the low maximum non-
cancer risk level (TOSHI of 0.004 based on actual emissions), we 
propose that the risks from the Chromium Anodizing source category are 
acceptable.
b. Ample Margin of Safety
    Although we are proposing that the risks from these source 
categories are acceptable, risk estimates for individuals in the 
exposed population are above 1-in-1 million. Consequently, we 
considered whether the MACT standard provides an ample margin of 
safety. As part of this analysis, we investigated available emissions 
control options that might reduce the risk associated with chromium 
compound emissions from the nationwide estimated 1,770 hard chromium 
electroplating, decorative chromium electroplating, and chromium 
anodizing operations. Once we identified the available emissions 
control options, we estimated the cost of these options and

[[Page 65092]]

estimated the emission reduction associated with each control option. 
To determine controlled baseline emissions nationwide, assumptions were 
made about the numbers and types of emission control technologies in 
use, and the control efficiencies achieved by those technologies. The 
distribution of emission control methods among the various types of 
chromium electroplating plants and plant sizes was estimated based on 
general knowledge of the industry. Table A.7 summarizes the nationwide 
costs and cost-effectiveness of these regulatory control options.

                                             Table A.7--Costs of Control Options for Chromium Electroplating
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                  Annualized      Cost-
                                                                           Number of     Emission     Capital       costs     effectiveness   MIR after
           Type of facility                      Control option             affected    reduction      costs      ($million/    ($million/   control (in-
                                                                           facilities     (TPY)      ($million)      yr)           ton)       1-million)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Large hard chromium electroplating....  HEPA filter retrofit............          132          1.0         35.1         18.4          36.3             6
Small hard chromium electroplating....  HEPA filter retrofit............          658          0.4         66.0         33.9          59.3             6
                                        CMP retrofit....................          392          0.2         36.6         11.1          33.1            10
Decorative chromium electroplating....  HEPA filter retrofit............          740          0.1        109.0         47.8           486             4
                                        CMP retrofit....................          644     \1\ 0.05         63.1         17.1           367            10
Chromium anodizing....................  HEPA filter retrofit............          240         0.02         43.9         17.9           895           < 1
                                        CMP retrofit....................          198    \1\ 0.009         22.9          5.6           649             2
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Based on an estimated control efficiency of 99.9 percent.

    For large hard chromium electroplating facilities, we evaluated the 
costs and emissions reductions associated with retrofitting existing 
tanks with HEPA filters. For small hard chromium electroplating 
facilities, we evaluated the same HEPA filter retrofit option, and also 
the option of retrofitting CMP systems on all tanks currently 
controlled with packed bed scrubbers. Retrofitting HEPA filters on 
existing tanks at large hard chromium electroplating plants would 
reduce nationwide emissions of chromium compounds by an estimated 1.0 
TPY from the estimated baseline level of 1.10 TPY. The estimated 
capital and annualized costs for this option would be $35,100,000 and 
$18,430,000, respectively. The cost-effectiveness would be $36,300,000 
per ton of HAP emissions reduced. Retrofitting HEPA filters on existing 
tanks at small hard chromium electroplating plants would reduce 
nationwide emissions of chromium compounds by an estimated 0.40 TPY 
from the estimated baseline level of 0.42 TPY. The estimated capital 
and annualized costs for this option would be $65,980,000 and 
$33,860,000, respectively. The cost-effectiveness would be $59,300,000 
per ton of HAP emissions reduced. Retrofitting CMP systems on all tanks 
currently controlled with packed bed scrubbers at small hard chromium 
electroplating plants would reduce nationwide emissions of chromium 
compounds by an estimated 0.19 TPY from the estimated baseline level of 
0.37 TPY. The estimated capital and annualized costs for this option 
would be $36,640,000 and $11,050,000, respectively. The cost-
effectiveness would be $33,100,000 per ton of HAP emissions reduced. 
The Benzene NESHAP emphasize the need to consider ``costs and the 
economic impacts of control,'' which implies some knowledge of 
affordability (54 FR 38046). The cost of the control options for hard 
chromium electroplating would impact over half of these facilities with 
estimated cost to sales ratios ranging from 8 percent to 22 percent. A 
cost to sales ratio greater than 3 percent may have a significant 
impact, including plant closure for many of these facilities.
    These additional control requirements would reduce the maximum 
lifetime individual cancer risk from the Hard Chromium Electroplating 
source category to approximately 4-in-1 million, based on actual 
emissions. We estimate that, considering MACT-allowable emissions 
levels, the maximum lifetime individual cancer risk from the Hard 
Chromium Electroplating source category would be reduced to 
approximately 6-in-1 million. The cancer incidence would be reduced to 
approximately 0.05 and the estimated number of people exposed higher 
than 1-in-1 million would be about 1 million.
    For decorative chromium electroplating, we evaluated the options of 
retrofitting HEPA filters on all existing tanks and the option of 
retrofitting CMP systems on the existing tanks that currently are not 
equipped with add-on control devices. Retrofitting HEPA filters on all 
existing decorative chromium electroplating tanks would reduce 
nationwide emissions of chromium compounds by an estimated 0.098 TPY 
from the estimated baseline level of 0.10 TPY. The estimated capital 
and annualized costs for this option would be $108,970,000 and 
$47,800,000, respectively. The cost-effectiveness would be $486,000,000 
per ton of HAP emissions reduced. Retrofitting CMP systems on all 
decorative chromium electroplating tanks that currently do not have 
add-on controls would reduce nationwide emissions of chromium compounds 
by an estimated 0.05 TPY from the estimated baseline level of 0.10 TPY. 
The estimated capital and annualized costs for this option would be 
$63,100,000 and $17,100,000, respectively. The cost-effectiveness for 
this option would be $367 million per ton of HAP emissions reduced. The 
additional control requirements for HEPA filters would reduce the 
maximum lifetime individual cancer risk from the Decorative Chromium 
Electroplating source category to approximately 4-in-1 million, based 
on actual emissions. Because we believe the actual emissions are 
essentially the same as the MACT-allowable emissions for the Decorative 
Chromium Electroplating source category, we estimate no difference 
between the risks from the allowable emission level and the actual 
emission level.
    For chromium anodizing, we evaluated the options of retrofitting 
HEPA filters on all existing tanks and the option of retrofitting CMP 
systems on the existing tanks that currently are not equipped with add-
on control devices. Retrofitting HEPA filters on all existing chromium 
anodizing tanks

[[Page 65093]]

would reduce nationwide emissions of chromium compounds by an estimated 
0.020 TPY from the estimated baseline level of 0.021 TPY. The estimated 
capital and annualized costs for this option would be $43,860,000 and 
$17,900,000, respectively. The cost- effectiveness would be 
$895,000,000 per ton of HAP emissions reduced. Retrofitting CMP systems 
on all chromium anodizing tanks that currently do not have add-on 
controls would not significantly reduce emissions. The estimated 
capital and annualized costs for this option would be $22,900,000 and 
$5,600,000, respectively. The cost-effectiveness for this option would 
be $649 million per ton of HAP emissions reduced. The additional 
control requirements for HEPA filters would reduce the maximum lifetime 
individual cancer risk from the Chromium Anodizing source category to 
less than 1-in-1 million, based on actual emissions. Because we believe 
the actual emissions are essentially the same as the MACT-allowable 
emissions for the Chromium Anodizing source category, we estimate the 
risk reduction based on allowable emissions to be the same as that for 
the actual emissions.
    Our risk analysis results show cancer risks to the individual most 
exposed of 70-in-1 million and 5-in-1 million based on actual and MACT-
allowable emissions, respectively, for the Decorative Chromium 
Electroplating and Chromium Anodizing source categories. For both of 
these categories, the cancer incidence is less than 0.01 cases per 
year. For decorative chromium electroplating, the number of people 
exposed to a cancer risk of 1-in-1 million or more is approximately 
390,000. For chromium anodizing, the number of people exposed to a 
cancer risk of 1-in-1 million or more is approximately 2,700.
    For the Hard Chromium Electroplating source category, our risk 
analysis shows cancer risks to the individual most exposed are 70-in-1 
million based on actual emissions levels and 90-in-1 million based on 
MACT-allowable emissions. The cancer incidence for this source category 
could be as high as 0.8 cases per year, and could be over 14 million 
people exposed to cancer risks of 1-in-1 million or greater due to 
emissions from hard chromium electroplating sources using highly 
conservative assumptions. As we stated previously, we believe we 
overestimated hard chromium electroplating emissions, the number of 
plants that perform hard chromium electroplating, and, therefore, that 
the risks from the resulting analyses are also overstated. Our 
supplemental risk analysis for this source category indicates a cancer 
incidence of 0.1 cases per year and 360,000 people exposed to cancer 
risks of greater than 1-in-1-million. This analysis indicates that the 
risk levels in the assessment are highly uncertain and err on the side 
of being conservative.
    Our analyses also show that, for these source categories, there is 
no potential for an adverse environmental effect or human health 
multipathway effects, and that acute and chronic non-cancer health 
impacts are unlikely. Our additional analysis of facility-wide risks 
showed that the maximum facility-wide cancer risk is 90-in-1 million, 
and that the maximum chronic non-cancer risks are unlikely to cause 
health impacts. Our additional analysis of the demographics of the 
exposed population shows that minorities face disproportionate risk 
from exposure to emissions from this category
    We do not believe there is a significant risk reduction from the 
housekeeping measures we are proposing under CAA section 112(d)(6). 
However, we are requesting information on any risk reductions from 
these housekeeping practices and whether we should consider adopting 
these practices under CAA section 112(f)(2).
    We considered all these factors in our ample margin of safety 
decision, and concluded that the costs of the options analyzed are not 
reasonable considering the emissions reductions and cancer health 
benefits potentially achievable with the controls. As a result, we 
propose that the existing MACT standard provides an ample margin of 
safety (considering cost, technical feasibility, and other factors) to 
protect public health for all three of these source categories. Thus, 
we are proposing to re-adopt the existing MACT standard to satisfy 
section 112(f) of the CAA.
    While we propose that the existing MACT standard for the Hard 
Chromium Electroplating source category is acceptable and provides an 
ample margin of safety, we are proposing additional requirements under 
CAA section 112(d)(6), as discussed below. Notwithstanding our proposal 
that the risks are acceptable, we remain concerned that up to 14.2 
million people may be exposed to cancer risks of 1-in-1 million or 
greater, and that there are disparities in risks for some demographic 
groups. While we are rejecting the option of adding HEPA filters or CMP 
as not cost-effective, we are specifically requesting comment on 
whether there are any cost-effective controls that may be able to 
reduce these risks. In particular, we are requesting States to identify 
any controls they have already required for these facilities, any 
controls they are currently considering, or any other controls of which 
they may be aware. We are also soliciting comment on whether our cost 
estimates for these options are accurate and whether these controls may 
be more cost-effective.
    In summary, we propose that the risks posed by these source 
categories are acceptable. We are also proposing that the current MACT 
standard provides an ample margin of safety to protect public health 
based on our conclusion that the controls available are not cost-
effective in light of the additional health protection the controls 
would provide. Thus, we are proposing to re-adopt the existing MACT 
standard to satisfy section 112(f) of the CAA.
5. What is our proposed decision on the technology review?
    To evaluate developments in practices, processes, and control 
technologies for the chromium electroplating source categories, several 
activities were performed. Public comments received on the proposed 
2002 amendments to the Chromium Electroplating MACT standards (67 FR 
38810, June 5, 2002) were reviewed to determine whether they identified 
any developments in practices, processes, or control technologies that 
warrant further consideration. A review was performed of the supporting 
documentation for the 2007 amendments to California's Airborne Toxic 
Control Measure (ATCM) for Chromium Plating and Chromium Anodizing 
Facilities. Finally, searches of the RBLC and the Internet were 
conducted to identify other practices, processes, or control 
technologies that could be applied to chromium electroplating.
    The 2004 amendments to the Chromium Electroplating MACT standards 
addressed three specific technology developments that occurred 
following promulgation of the original MACT standard: The use of WAFS 
for hard chromium electroplating emission control; instrumental 
differences in surface tension measurements for demonstrating 
compliance with electroplating bath surface tension limits; and 
enclosing hoods for electroplating tanks. Because those technology 
developments have already been addressed and we are not aware of any 
improvements to them, they are not discussed further. The following 
paragraphs describe all developments in practices, processes, and 
control technologies that we identified and that

[[Page 65094]]

were thus considered for the technology review, along with our 
conclusions.
a. Emission Elimination Device
    An emission elimination device (EED), which is also referred to as 
a ``Merlin cover,'' consists of a tank cover that includes a porous 
membrane that allows gases to escape, but captures droplets and mist 
emanating from the electroplating tank. While these tank covers are 
available, we do not believe any chromium electroplating or anodizing 
facilities are currently using an EED due to the impracticality of 
covering the electroplating tank while plating is underway. Because 
these devices are not known to be used in this industry and because it 
is unclear that they are feasible for these operations, we concluded 
that it is not necessary to revise the MACT standard to require this 
control under section 112(d)(6). However, we request comment on tanks 
or processes in which an EED could practicably be used by chromium 
electroplating or anodizing facilities.
b. HEPA Filters
    Although HEPA filters have been on the market for decades, they 
were not considered to be a practical control method for electroplating 
tank emissions when the MACT standards were developed due to potential 
problems with clogging and the availability of several other types of 
mist eliminator technologies that had been proven to be effective in 
reducing emissions from electroplating tanks. However, in the past 
decade, facilities in California have increasingly used HEPA filters to 
meet the emission limits of the State's ATCM for Chromium Plating and 
Chromic Acid Anodizing Facilities. In October 2007, the California Air 
Resources Board (CARB) amended the ATCM to further tighten emission 
limits and to require HEPA filters on all new chromium electroplating 
and anodizing tanks. In those applications, HEPA filters act as a 
second stage of control, with the first stage generally consisting of a 
mesh pad mist eliminator or other device that removes large particles 
from the exhaust stream prior to the HEPA filter. Discussions with 
State and local agency staff in California indicate no technological 
problems with using HEPA filters for chromium electroplating emissions 
control. As part of this technology review, HEPA filters have been 
considered as a possible control option for sources subject to the 
Chromium Electroplating MACT standards. The costs of requiring HEPA 
filters were estimated, and are discussed above in section V.A.4.b of 
this preamble. In light of the high cost of this option as compared 
with the risk reductions it would achieve, we are proposing that it is 
not necessary to revise the MACT standard under section 112(d)(6) to 
require HEPA filters. However, we request comment on whether we should 
require HEPA filters for new source MACT.
c. Wetting Agent Fume Suppressants (WAFS)
    The MACT standard allows the use of WAFS as a compliance 
alternative for meeting the applicable emission limit. WAFS are used in 
most decorative chromium electroplating and chromium anodizing tanks 
and in many hard chromium electroplating tanks for emission control. 
Historically, the most effective types of WAFS have been based on 
perfluorooctyl sulfonate (PFOS). The PFOS-based WAFS used in the 
chromium electroplating industry are part of a family of chemical 
compounds categorized as long-chain perfluorinated chemicals (PFC). As 
noted in a 2010 California Office of Health Hazard Assessment report, 
Perfluorooctane sulfonate (PFOS) and Its Salts and Transformation and 
Degradation Precursors,\34\ these compounds have persistent, 
bioaccumulative, and toxic characteristics and are a particular concern 
for children's health.
---------------------------------------------------------------------------

    \34\ This report is available at http://www.oehha.org/prop65/
CRNR_notices/pdf_zip/070910_PFOS_CIC.pdf.
---------------------------------------------------------------------------

    Over the last several years there have been developments associated 
with the use of WAFS as a compliance alternative. There are now several 
types of WAFS on the market that do not include PFOS chemicals and have 
been proven effective for use in hard chromium and decorative chromium 
electroplating baths that we believe are cost-effective. Furthermore, 
these non-PFOS WAFS are not associated with any known adverse health 
effects. Although the non-PFOS WAFS have not been used extensively in 
the chromium anodizing industry, we are not aware of any technical 
reasons to preclude their use and effectiveness for chromium anodizing 
baths. However, we seek comment on this, as well as on our assessment 
that their use is cost-effective. Because of the adverse non-air 
quality health and environmental impacts associated with using PFOS-
based WAFS (i.e., the increasing concern over the presence of long-
chain PFC in the environment), we are proposing under CAA section 
112(d)(6) to revise the scope of the compliance alternative to no 
longer allow the addition of PFOS-based WAFS to tanks as a control 
method for these source categories. We solicit comment on all aspects 
of this change, including the non-air quality health and environmental 
impacts associated with using PFOS based WAFS.
    For new sources, we are proposing that no PFOS-based WAFS could be 
used upon startup. For existing sources, we are proposing that no PFOS-
based WAFS could be added to the electroplating or anodizing tanks 
beginning 3 years after promulgation of the final amendments; however, 
the tanks may continue operating with the remaining PFOS-based WAFS in 
them after that date until it is depleted. Under these amendments, 
these requirements would be specified in 40 CFR 63.342(c)(1)(iv) and 
(2)(vi) for hard chromium electroplating tanks, 40 CFR 63.342(d)(3) for 
decorative chromium electroplating and chromium anodizing tanks, and 40 
CFR 63.342(e)(2) for decorative chromium electroplating tanks that use 
a trivalent chromium bath. A definition of PFOS-based fume suppressants 
also would be added to 40 CFR 63.341.
d. Housekeeping Procedures
    We are also proposing under CAA section 112 (d)(6) to incorporate 
several housekeeping requirements into 40 CFR 63.342(f). In our review 
of the 2007 amendments to California's ATCM for Chromium Plating and 
Chromic Acid Anodizing Facilities, we found this rule required several 
housekeeping procedures that were not included in the housekeeping 
procedures required by the Chromium Electroplating MACT standards. 
These measures would potentially reduce fugitive chromium emissions 
from chromium electroplating and anodizing operations. In view of the 
implementation of these procedures in California and the potential for 
fugitive emissions reductions, we are proposing to add these procedures 
to the Chromium Electroplating MACT standards. The proposed 
housekeeping procedures would include storage requirements for any 
substance that contains hexavalent chromium as a primary ingredient; 
controls for the dripping of bath solution resulting from dragout; 
splash guards to minimize overspray and return bath solution to the 
electroplating or anodizing tank; a requirement to promptly clean up or 
contain all spills of any substance containing hexavalent chromium; 
requirements for the routine cleaning or stabilizing of storage and 
work surfaces, walkways, and other surfaces potentially contaminated 
with hexavalent chromium; a requirement to

[[Page 65095]]

install a barrier between all buffing, grinding, or polishing 
operations and electroplating or anodizing operations; and requirements 
for the storage, disposal, recovery, or recycling of chromium-
containing wastes. The proposed housekeeping procedures would be listed 
in a new Table 2 to 40 CFR 63.342. In addition, this proposed action 
would require owners and operators to incorporate these housekeeping 
procedures in the facility Operation and Maintenance Plan specified in 
section 40 CFR 63.342(f)(3) and implement them, and a new definition 
would be added to 40 CFR 63.341(a) to clarify what is meant by the term 
``contains hexavalent chromium as a primary ingredient.'' The proposed 
compliance date for implementing the housekeeping procedures would be 6 
months after promulgation of the final amendments.
6. What are the other actions we are proposing?
a. SSM Provisions
    Consistent with Sierra Club v. EPA, EPA is proposing that standards 
in this rule would apply at all times. The existing MACT standards for 
these three source categories already specifies that the emission 
limitations apply ``during periods of startup and shutdown'' but not 
during malfunctions. We are proposing to revise this paragraph to 
remove the sentence indicating that the emission limitations do not 
apply during malfunctions. We are maintaining the malfunction-
associated reporting and recordkeeping requirements in 40 CFR 63.346 
and 40 CFR 63.347 with minor revisions. We are proposing to add 
language to 40 CFR 63.344(a) to clarify the conditions during which 
performance tests shall be conducted and to specify in Table 1 that the 
performance test specifications in 40 CFR 63.7(e)(1) of the General 
Provisions do not apply. We are also proposing to add a general duty 
provision to minimize emissions into 40 CFR 63.342(a)(1). In addition, 
we are proposing to promulgate an affirmative defense against civil 
penalties for exceedances of emission standards caused by malfunctions, 
as well as criteria for establishing the affirmative defense. EPA has 
attempted to ensure that we have not incorporated into the proposed 
regulatory language any provisions that are inappropriate, unnecessary, 
or redundant in the absence of the SSM exemption. We are specifically 
seeking comment on whether there are any such provisions that we have 
inadvertently incorporated or overlooked.
b. Rule Improvements
    In addition, we identified the need for revisions of the standards 
to correct editorial errors, make clarifications, or address issues 
with implementation or determining compliance with the rule provisions.
    Monitoring and Testing Requirements. We are proposing to revise 40 
CFR 63.344(e), which addresses compliance provisions for multiple 
sources controlled by a common add-on air pollution control device. 
This section of the MACT standard references testing by Method 306, 
without any mention of Method 306A. Since Method 306A is an alternative 
to Method 306, we are proposing to revise section 40 CFR 63.344(e) to 
clarify that testing can be performed by either Method 306 or Method 
306A.
    To correct inconsistencies between the amendments made to 40 CFR 
part 63, subpart N in 2004 (69 FR 42885) and Method 306B, we are 
proposing to revise Method 306B, which specifies procedures for 
measuring the surface tension of chromium electroplating and anodizing 
baths. In addition, the proposed amendments would help to ensure that 
surface tension measurements made using stalagmometers are accurate. 
Under the proposed amendments, section 1.2 of Method 306B would be 
revised to clarify that the method also applies to hard chromium 
electroplating tanks. Section 11.1 would be revised to include 
procedures for checking the accuracy of, and cleaning, a stalagmometer 
before using the stalagmometer to measure surface tension. The proposed 
revisions to section 11.1 are consistent with the CARB ATCM for 
Hexavalent Chromium for Decorative and Hard Chrome plating and Chromic 
Acid Anodizing Facilities. Maintaining surface tension measuring 
devices is critical for obtaining accurate measurements. Method 306B 
currently references standard procedures for the use of tensiometers 
(ASTM Method D 1331-89), but not for the use of stalagmometers. The 
proposed amendment to section 11.1 would help to ensure that 
stalagmometers used to demonstrate compliance with surface tension 
limits are maintained and used properly. Finally, section 11.2 would be 
revised to account for the differences in surface tension limits, 
depending on the type of instrument used (tensiometer or 
stalagmometer).
    Rule Corrections. To eliminate a discrepancy between the Chromium 
Electroplating MACT standards in subpart N of part 63 and the General 
Provisions in subpart A of part 63, this proposed action would also 
revise the trigger for semiannual compliance reports specified in 40 
CFR 63.347(h)(2)(A) to be consistent with the trigger specified in the 
General Provisions. Subpart N currently provides that a semiannual 
report must be submitted if both the duration of excess emissions 
exceeds 1 percent of the source operating time and the duration of air 
pollution control device malfunctions exceeds 5 percent of the source 
operating time during the reporting period; however, 40 CFR 
63.10(e)(3)(viii) of the General Provisions requires submitting a 
semiannual report if either condition occurs. We are proposing to 
revise 40 CFR part 63, subpart N to require semiannual reports to be 
submitted if either condition occurs.

B. What are the results and proposed decisions for the Group I Polymers 
and Resins Production source categories?

    The National Emission Standards for Hazardous Air Pollutant 
Emissions: Group I Polymers and Resins were promulgated on September 5, 
1996 (62 FR 46925), and codified at 40 CFR part 63, subpart U. The 
Polymers and Resins I MACT standard applies to major sources and 
regulates HAP emissions from nine source categories: Butyl Rubber 
Production, Epichlorohydrin Elastomers Production, Ethylene Propylene 
Rubber Production, Hypalon\TM\ Production, Neoprene Production, Nitrile 
Butadiene Rubber Production, Polybutadiene Rubber Production, 
Polysulfide Rubber Production, and Styrene Butadiene Rubber and Latex 
Production.
    The Polymers and Resins I MACT standards regulate HAP emissions 
resulting from the production of elastomers (i.e., synthetic rubber). 
An elastomer is a synthetic polymeric material that can stretch to at 
least twice its original length and then return rapidly to 
approximately its original length when released. Elastomers are 
produced via a polymerization/copolymerization process, in which 
monomers undergo intermolecular chemical bond formation to form a very 
large polymer molecule. Generally, the production of elastomers entails 
four processes: (1) Raw material (i.e., solvent) storage and refining; 
(2) polymer formation in a reactor (either via the solution process, 
where monomers are dissolved in an organic solvent, or the emulsion 
process, where monomers are dispersed in water using a soap solution); 
(3) stripping and material recovery; and (4) finishing (i.e., blending, 
aging, coagulation, washing, and drying).

[[Page 65096]]

    Sources of HAP emissions from elastomers production include raw 
material storage vessels, front-end process vents, back-end process 
operations, wastewater operations, and equipment leaks. The ``front-
end'' processes include pre-polymerization, reaction, stripping, and 
material recovery operations; and the ``back-end'' process includes all 
operations after stripping (predominately drying and finishing). 
Typical control devices used to reduce organic HAP emissions from 
front-end process vents include flares, incinerators, absorbers, carbon 
adsorbers, and condensers. In addition, hydrochloric acid formed when 
chlorinated organic compounds are combusted are controlled using 
scrubbers. Emissions from storage vessels are controlled by floating 
roofs or by routing them to a control device.
    While emissions from back-end process operations can be controlled 
with control devices such as incinerators, the most common method of 
reducing these emissions is the pollution prevention method of reducing 
the amount of residual HAP that is contained in the raw product going 
to the back-end operations. Emissions from wastewater are controlled by 
a variety of methods, including equipment modifications (e.g., fixed 
roofs on storage vessels and oil water separators; covers on surface 
impoundments, containers, and drain systems), treatment to remove the 
HAP (steam stripping, biological treatment), control devices, and work 
practices.
    Emissions from equipment leaks are typically reduced by leak 
detection and repair work practice programs, and in some cases, by 
equipment modifications. Each of the seven Group I Polymers and Resins 
Production source categories addressed in this proposal are discussed 
further below.
1. Epichlorohydrin Elastomers Production
    Epichlorohydrin Elastomers Production is one of the source 
categories for which we proposed RTR decisions on October 10, 2008.
a. Overview of the Source Category
    Epichlorohydrin elastomers are prepared from the polymerization or 
copolymerization of epichlorohydrin or other monomers. Epichlorohydrin 
elastomers are produced by a solution polymerization process, typically 
using toluene as the solvent in the reaction. The main epichlorohydrin 
elastomers are polyepichlorohydrin, epi-ethylene oxide (EO) copolymer, 
epi-allyl glycidyl ether (AGE) copolymer, and epi-EOAGE terpolymer. 
Epichlorohydrin elastomers are widely used in the automotive industry.
    We identified one currently operating epichlorohydrin elastomers 
production facility subject to the Polymers and Resins I MACT standard. 
Toluene accounts for the majority of the HAP emissions from the 
epichlorohydrin elastomers production processes at this facility 
(approximately 44 TPY and 99 percent of the total HAP emissions by 
mass). This facility also reported relatively small emissions of 
epichlorohydrin and ethylene oxide. The majority of HAP emissions are 
from back-end process vents (approximately 82 percent of the total HAP 
by mass). We estimate that the MACT-allowable emissions (i.e., the 
maximum emission levels allowed if in compliance with the MACT 
standard) from this source category are approximately equal to the 
reported, actual emissions. For more detail about this estimate of the 
ratio of actual to MACT-allowable emissions, see the memo in the docket 
for this action describing the estimation of MACT-allowable emission 
levels and associated risks and impacts.
b. What data were used in our risk analyses?
    We initially created a preliminary data set for the Epichlorohydrin 
Elastomers Production source category using information we collected 
directly from industry on emissions data and emissions release 
characteristics. We also reviewed the emissions and other data to 
identify data anomalies that could affect risk estimates. On March 29, 
2007, we published an ANPRM (72 FR 29287) for the express purpose of 
requesting comments on and updates to this data set, as well as to the 
data sets for the other source categories addressed in that ANPRM. 
Comments received in response to the ANPRM were reviewed and 
considered, and we made adjustments to the data set where we concluded 
the comments supported such adjustment. After making appropriate 
changes to the data set based on this public data review process, the 
data set on which we based the initial proposal was created. This data 
set was used to conduct the risk assessment and other analyses for the 
Epichlorohydrin Elastomers Production source category that formed the 
basis for the proposed RTR included in the October 10, 2008, proposal.
    We have continued to scrutinize the existing data set and have 
evaluated any additional data that became available subsequent to the 
October 10, 2008, proposal. Specific questions we had concerning 
current operations led us to develop a questionnaire and ask for 
updated emissions and emissions release characteristics information. 
This information was requested from the facility in May 2010 using the 
authority of section 114 of the CAA. We updated our data set for this 
source category based on the information received through this request.
c. What are the results of the risk assessments and analyses?
    We have conducted a revised inhalation risk assessment for the 
Epichlorohydrin Elastomers Production source category. We have also 
conducted an assessment of facility-wide risk, and performed a 
demographic analysis of population risks. Table B.1.1 provides an 
overall summary of the results of the revised inhalation risk 
assessment.

                             Table B.1.1--Epichlorohydrin Elastomers Production Revised Inhalation Risk Assessment Results *
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                               Maximum individual                                 Maximum chronic non-
                                                cancer risk (in 1                     Annual        cancer TOSHI \3\
                                                  million) \2\         Population     cancer   --------------------------
          Number of facilities\1\          --------------------------  at risk >=   incidence                               Maximum off-site acute non-
                                               Actual     Allowable      1-in-1     (cases per     Actual     Allowable            cancer HQ \4\
                                             emissions    emissions     million       year)      emissions    emissions
                                               level        level                                  level        level
--------------------------------------------------------------------------------------------------------------------------------------------------------
1.........................................           10           10          800       0.0001          0.1          0.1  HQREL = 0.2 epichlorohydrin
--------------------------------------------------------------------------------------------------------------------------------------------------------
* All results are for impacts out to 50 km from every source in the category.
\1\ Number of facilities evaluated in the risk analysis.
\2\ Maximum individual excess lifetime cancer risk.

[[Page 65097]]

\3\ Maximum TOSHI. The target organ with the highest TOSHI for the Epichlorohydrin Elastomer Production 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 threshold. See section IV.A. of this preamble for explanation of acute threshold values.

    The inhalation risk modeling was performed using actual emissions 
level data. As shown in Table B.1.1, the results of the revised 
inhalation risk assessment indicated the maximum lifetime individual 
cancer risk could be as high as 10-in-1 million, the maximum chronic 
non-cancer TOSHI value could be as high as 0.1, and the maximum off-
facility-site acute HQ value could be as high as 0.2, based on the 
actual emissions level and the REL value for epichlorohydrin. The total 
estimated national cancer incidence from these facilities based on 
actual emission levels is 0.0001 excess cancer cases per year, or one 
case in every 10,000 years.
    Based on our analysis, we believe that actual emissions approximate 
emissions allowable under the MACT standard. Therefore, the risk 
results for MACT-allowable emissions are approximately equal to those 
for actual emissions. For more detail about the estimate of the ratio 
of actual to MACT-allowable emissions, see the memo in the docket for 
this action describing the estimation of MACT-allowable emission levels 
and associated risks and impacts.
    There were no reported emissions of PB-HAP; therefore, we do not 
expect potential for human health multipathway risks or adverse 
environmental impacts.
    Table B.1.2 displays the results of the facility-wide risk 
assessment. This assessment was conducted based on actual emission 
levels.

  Table B.1.2--Epichlorohydrin Elastomers Production Facility-Wide Risk
                           Assessment Results
------------------------------------------------------------------------

------------------------------------------------------------------------
Maximum facility-wide individual cancer risk (in 1                    10
 million)............................................
    Epichlorohydrin Elastomer Production source                     100%
     category contribution to this maximum facility-
     wide individual cancer risk \1\.................
Maximum facility-wide chronic non-cancer TOSHI.......                0.1
    Epichlorohydrin Elastomer Production source                     100%
     category contribution to this maximum facility-
     wide non-cancer TOSHI \1\.......................
------------------------------------------------------------------------
\1\ Percentage shown reflects Epichlorohydrin Elastomer Production
  source category contribution to the maximum facility-wide risks at the
  facility with the maximum risk value shown.

    As shown in Table B.1.2, the maximum individual cancer risk from 
all HAP emissions at the one facility that contains epichlorohydrin 
elastomers production processes subject to the Group I Polymers and 
Resins MACT standard is estimated to be 10-in-1 million, and the 
maximum chronic non-cancer TOSHI value is estimated to be 0.1. The 
estimated proportion of the risk attributable to Epichlorohydrin 
Elastomers Production source category processes at this facility is 
approximately 100 percent for cancer risks and 100 percent for chronic 
non-cancer risk.
    The results of the demographic analyses performed to investigate 
the distribution of risks above 1-in-1 million, based on actual 
emissions levels for the population living within 5 km of the 
facilities, among various demographic groups are provided in a report 
available in the docket for this action and summarized in Table B.1.3 
below.

                                        Table B.1.3--Epichlorohydrin Elastomers Demographic Risk Analysis Results
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                 Population with risk greater than 1-in-1 million
                                              Maximum   ------------------------------------------------------------------------------------------------
              Emissions basis               risk  (in 1                                       Other and    Hispanic                Below the  Over 25 W/
                                              million)      Total    Minority %    African   multiracial   or Latino    Native      poverty     O a HS
                                                         (millions)              American %       %            %      American %    level %    diploma %
--------------------------------------------------------------------------------------------------------------------------------------------------------
Nationwide................................          n/a         285          25          12           12          14         0.9          13          13
Source Category...........................           10      0.0008          54          53            1           1         0.4          20          11
Facility-wide.............................           10        0.01          52          50            2           1         0.2          23          14
--------------------------------------------------------------------------------------------------------------------------------------------------------

    The results of the demographic analysis show that, for the 
Epichlorohydrin Elastomers Production source category, of the 
population of 800 people with cancer risk greater than 1-in-1 million, 
54 percent could be classified as a ``Minority,'' 53 percent are 
included the ``African-American'' demographic group, and 20 percent are 
included the ``Below Poverty Level,'' demographic group. The percentage 
of the population within 5 km of a epichlorohydrin elastomers 
production facility and with a cancer risk greater than 1-in-1 million 
is higher than expected for these demographic categories based on the 
typical distribution of these demographic groups across the United 
States. The table also shows that the results of the demographic 
analysis for the facility-wide emissions are similar to the results for 
the source category.
    Details of these assessments and analyses can be found in the 
residual risk documentation as referenced in section IV.A. of this 
preamble, which is available in the docket for this action.
d. What are our proposed decisions on risk acceptability and ample 
margin of safety?
    October 2008 Proposed Decision. In our October 10, 2008, proposal, 
we proposed that the risks 0f 30-in-1 million were acceptable because 
the risks results indicated that cancer risks to the individual most 
exposed to emissions from the category were greater than 1-in-1 
million, but less than 100-in-1 million. We then analyzed other risk 
factors in the ample margin of safety determination. In this analysis, 
we proposed that emissions from the source category posed no potential 
for

[[Page 65098]]

an adverse environmental effect, did not pose potential for human 
health multipathway risks, and were unlikely to cause acute or chronic 
non-cancer health impacts. We also identified one emissions control 
option that would reduce risks. We proposed that such control was not 
necessary to protect public health with an ample margin of safety in 
light of the high cost and limited addition health protection it would 
provide. Therefore, we proposed that the existing standard provided an 
ample margin of safety and proposed to re-adopt the existing MACT 
standard to satisfy section 112(f) of the CAA.
    Risk Acceptability. The revised risk analysis we performed for this 
proposal indicates that the cancer risks to the individual most exposed 
is 10-in-1 million based on both actual and MACT-allowable emissions. 
The cancer incidence and the number of people exposed to cancer risks 
of 1-in-1 million or greater are not significantly changed from the 
risk identified in the October 2008 proposal. Similarly, the risk 
analysis continued to show no potential for an adverse environmental 
effect or human health multipathway effects, and that acute or chronic 
non-cancer health impacts are unlikely. Our additional analysis of 
facility-wide risks showed that the maximum facility-wide cancer risk 
is 10-in-1 million and that the maximum chronic non-cancer risks are 
unlikely to cause health impacts. Our additional analysis of the 
demographics of the exposed population shows disparities in risks 
between demographic groups for the 800 people exposed at risks of 1-in-
1 million. Based on this low cancer risk level and in consideration of 
other health measures and factors, including the low cancer incidence 
(one case in every 10,000 years) and the low maximum non-cancer risk 
level (TOSHI of 0.1), we propose that the risks from the 
Epichlorohydrin Elastomers Production are acceptable.
    Ample Margin of Safety. Because we are proposing that the risks are 
acceptable, but still above 1-in-1 million, we then reconsidered our 
2008 ample margin of safety decision. We have not identified any 
additional control options or any changes to the previously analyzed 
control option. Our analysis does not indicate a change in the 
emissions reductions that could be achieved or the cost of control for 
the control option considered in the October 2008 proposal. Therefore, 
we continue to propose that the current MACT standard provides an ample 
margin of safety to protect public health and the environment, and we 
are proposing to re-adopt the existing MACT standard to satisfy section 
112(f) of the CAA.
e. What are our proposed decisions on the technology review?
    In the October 10, 2008 proposal, we identified no advancements in 
practices, processes, and control technologies applicable to the 
emission sources in the Group I Polymers and Resins Production source 
categories in our technology review, and we proposed to re-adopt the 
existing MACT standard to satisfy section 112(d)(6) of the CAA. In that 
review, we examined the regulatory requirements and/or technical 
analyses for subsequently promulgated air toxics regulations with 
similar types of emissions sources as those in the Group I Polymers and 
Resins Production source categories, and we conducted a search of the 
RBLC for controls for VOC- and HAP-emitting processes in the Group I 
Polymers and Resins Production source categories. We have not 
identified any additional developments in practices, processes, and 
control technologies since the proposal date for the Epichlorohydrin 
Elastomers Production source category. Thus, we are proposing that it 
is not necessary to revise the MACT standard pursuant to section 
112(d)(6) of the CAA.
f. What other actions are we proposing?
    SSM Provisions. We are proposing to eliminate the SSM exemption in 
the Group 1 Polymers and Resins MACT standard. Consistent with Sierra 
Club v. EPA, EPA is proposing that standards in this rule would apply 
at all times. We are proposing several revisions to 40 CFR part 63, 
subpart U. Specifically, we are proposing to revise Table 1 to indicate 
that the requirements of 40 CFR 63.6(e) of the General Provisions do 
not apply. The 40 CFR 63.6(e) requires owner or operators to act 
according to the general duty to ``operate and maintain any affected 
source, including associated air pollution control equipment and 
monitoring equipment, in a manner consistent with safety and good air 
pollution control practices for minimizing emissions.'' We are 
separately proposing to incorporate this general duty to minimize into 
40 CFR 63.483(a). The 40 CFR 63.6(e) also requires the owner or 
operator of an affected source to develop a written SSM plan. We are 
proposing to remove the SSM plan requirement. We are proposing to 
remove the explanation of applicability of emissions standards during 
periods SSM in 40 CFR 63.480(j); remove the malfunction plan from 40 
CFR 63.482 and revise the definition of initial start-up to remove 
references to malfunctions in this section; clarify that representative 
conditions do not include periods of SSM throughout the rule; remove 
references to periods of SSM in monitoring; and revise the SSM-
associated recordkeeping and reporting requirements in 40 CFR 63.506 to 
require reporting and recordkeeping for periods of malfunction. We are 
also proposing to revise Table 1 to indicate that SSM-related 
provisions in 40 CFR 63.6(f)(1), 40 CFR 63.7(e)(1), and 40 CFR 
63.10(d)(5)(i) of the General Provisions do not apply. In addition, we 
are proposing to promulgate an affirmative defense against civil 
penalties for exceedances of emission standards caused by malfunctions, 
as well as criteria for establishing the affirmative defense.
    EPA has attempted to ensure that we have not incorporated into 
proposed regulatory language any provisions that are inappropriate, 
unnecessary, or redundant in the absence of the SSM exemption. We are 
specifically seeking comment on whether there are any such provisions 
that we have inadvertently incorporated or overlooked.
    Significant Emission Points Not Previously Regulated Review. We 
identified the absence of a limit for a significant emissions source 
within the provisions of the Group I Polymers and Resins MACT standard 
that apply to the Epichlorohydrin Elastomers Production source 
category. Specifically, there are no back-end process operation 
emission limits for this source category.\35\ As these processes are 
major sources of emissions for the one facility in the source category, 
we are proposing to set standards for back-end process operations under 
CAA section 112(d)(2) and (d)(3) in this action.
---------------------------------------------------------------------------

    \35\ Note that these uncontrolled emissions were included in the 
baseline risk assessment.
---------------------------------------------------------------------------

    As there is only one facility in the source category, the emissions 
level currently being achieved by this facility represents the MACT 
floor. The annual HAP emissions from the back-end process operations at 
this facility are approximately 36 TPY of toluene. There are two 
separate dryer vents, one emitting around 24 TPY of toluene, and the 
other emitting around 12 TPY of toluene. Neither of these vents is 
controlled. Therefore, we have determined that the MACT floor for these 
processes is 36 TPY based on the current level of HAP stripping and 
recovery, given current production levels, but which would fluctuate 
proportionally with an increase or decrease in production levels.
    As part of our beyond-the-floor analysis, we considered 
alternatives

[[Page 65099]]

more stringent than the MACT floor option. We identified one option 
using add-on emission controls that would require the ducting of 
emissions from the back-end process operations to a control device, 
such as an incinerator. This option would also require an initial 
performance test of the incinerator and continuous parameter monitoring 
averaged daily. The capital costs of this option are estimated to be 
approximately $600,000 and the total annual costs are estimated to be 
approximately $1,100,000. We estimate that an incinerator would achieve 
an emissions reduction of 98 percent, resulting in a HAP decrease of 
approximately 35 TPY, with a cost- effectiveness of approximately 
$31,000/ton. Table B.2.4 summarizes the cost and emission reduction 
impacts of the proposed options. Because the reduction in HAP would be 
due to toluene, no reduction of cancer risk would result from this 
control option.

               Table B.1.4--Epichlorohydrin Elastomer Production Facility Back-End Options Impacts
----------------------------------------------------------------------------------------------------------------
                                                                                                      Cost-
                                                                                                effectiveness as
                                                                                                   compared to
         Regulatory alternatives            HAP emissions     Capital cost       Annual cost        baseline
                                              (TPY HAP)        ($million)       ($million/yr)  -----------------
                                                                                                    $/Ton HAP
                                                                                                     Removed
----------------------------------------------------------------------------------------------------------------
Baseline................................                36  ................  ................  ................
1 (MACT floor)..........................                36                 0                 0  ................
2 (Beyond-the-floor)....................                 1               0.6               1.1            31,000
----------------------------------------------------------------------------------------------------------------

    In addition to the cost and emission reduction impacts shown in 
Table B.1.4, we estimate that the beyond-the-floor option would result 
in increases in criteria pollutant and carbon dioxide emissions (PM-0.2 
TPY, SO2-0.03 TPY, NOX-12 TPY, CO-2 TPY, and 
CO2-7,000 TPY), and an increase in energy use of 
approximately 117,000 million British thermal units (BTU)/year at a 
cost of approximately $33,000/year.
    We believe that the costs and other impacts of this beyond-the-
floor option are not reasonable, given the level of emission reduction. 
Therefore, we are proposing an emission standard that reflects the MACT 
floor option. We are requesting comment on this analysis and these 
options.
    As noted above, we are proposing that the MACT standard, prior to 
the implementation of the proposed emission limitation to the back-end 
process operations discussed in this section, provides an ample margin 
of safety to protect public health. Therefore, we maintain that after 
the new standard's implementation, the rule will continue to provide an 
ample margin of safety to protect public health. Consequently, we do 
not believe it will be necessary to conduct another residual risk 
review under CAA section 112(f) for this source category 8 years 
following promulgation of new back-end process limitations, merely due 
to the addition of this new MACT requirement.
2. Polybutadiene Rubber Production
    Polybutadiene Rubber Production is one of the source categories for 
which we proposed RTR decisions on October 10, 2008.
a. Overview of the Source Category
    Polybutadiene rubber is a homopolymer of 1,3-butadiene (i.e., 1,3-
butadiene is the only monomer used in the production of this polymer). 
While both the solution and emulsion polymerization processes can be 
used to produce polybutadiene rubber, all currently operating 
facilities in the United States use a solution process. In the solution 
process, the reaction is conducted in an organic solvent (hexane, 
toluene, or a non-HAP organic solvent), which helps to dissipate heat 
generated by the reaction and control the reaction rate. While 
polybutadiene rubber is the primary product at these facilities, 
styrene-butadiene rubber can also be produced as a minor product by 
adding styrene as a monomer. Most of the polybutadiene rubber 
manufactured in the United States is used in the production of tires in 
the construction of the tread and sidewalls. Polybutadiene rubber is 
also used as a modifier in the production of other polymers and resins 
(e.g., polystyrene).
    We identified five currently operating polybutadiene rubber 
production facilities subject to the Polymers and Resins I MACT 
standard. Some of these facilities are located at plant sites that also 
have other HAP-emitting sources regulated under separate MACT 
standards, which have been or will be addressed in separate regulatory 
actions. Three of the polybutadiene rubber production facilities use 
hexane as the solvent in their solution process, one facility uses 
toluene as its solvent, and the fifth uses a non-HAP organic solvent. 
Overall, hexane and toluene account for the majority of the HAP 
emissions from this source category (approximately 1,600 TPY hexane, 
which represents 70 percent of the total HAP emissions by mass, and 500 
TPY toluene, which represents 23 percent). The facilities in this 
source category also reported emissions of styrene, 1,3-butadiene, 
ethylbenzene, and relatively minor quantities of other HAP. The 
majority of HAP emissions are from back-end process operations 
(approximately 70 percent of the total HAP by mass). For all emission 
sources except the back-end process operations, the actual emissions 
level is representative of the MACT-allowable level. For back-end 
process operations, we estimate that MACT-allowable emissions from this 
source category could be as high as seven times the actual emissions. 
Because these back-end limitations are production-based, this estimate 
was made by comparing the actual emissions levels to the emissions 
calculated using the limitations and production levels. For more detail 
about the estimate of the ratio of actual to MACT-allowable emissions, 
see the memo in the docket for this action describing the estimation of 
MACT-allowable emission levels and associated risks and impacts.
b. What data were used in our risk analyses?
    We initially created a preliminary data set for the Polybutadiene 
Rubber Production source category using information we collected 
directly from industry on emissions data and emissions release 
characteristics. We also reviewed the emissions and other data to 
identify data anomalies that could affect risk estimates. On March 29, 
2007, we published an ANPRM (72 FR 29287) for the express purpose of 
requesting comments on, and updates

[[Page 65100]]

to, this data set, as well as to the data sets for the other source 
categories addressed in that ANPRM. Comments received in response to 
the ANPRM were reviewed and considered. We made adjustments to the data 
set where we concluded the comments supported such adjustment. After 
making appropriate changes to the data set based on this public data 
review process, the data set on which we based the initial proposal was 
created. This data set was used to conduct the risk assessment and 
other analyses for the Polybutadiene Rubber Production source category 
that formed the basis for the proposed actions included in the October 
10, 2008, proposal. We have continued to scrutinize the data set and 
any additional data that have become available since the October 10, 
2008, proposal.
c. What are the results of the risk assessments and analyses?
    We have conducted a revised inhalation risk assessment for the 
Polybutadiene Rubber Production source category. We have also conducted 
an assessment of facility-wide risk and performed a demographic 
analysis of population risks. Table B.2.1 provides an overall summary 
of the results of the revised inhalation risk assessment.

                                                         Table B.2.1--Polybutadiene Rubber Revised Inhalation Risk Assessment Results *
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                 Maximum individual cancer risk                                     Maximum chronic non-cancer TOSHI
                                                       (in 1 million) \2\                           Annual cancer                  \3\
                                               ----------------------------------  Population at      incidence    ----------------------------------
           Number of  facilities\1\                                 Allowable      risk >= 1-in-1     (cases per         Actual         Allowable      Maximum off-site acute  non-cancer HQ \4\
                                                     Actual         emissions         million           year)          emissions        emissions
                                                emissions level       level                                              level            level
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
5.............................................              30               30           24,000            0.003              0.3              0.3   HQREL = 1 toluene
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
* All results are for impacts out to 50 km from every source in the category.
\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 Polybutadiene Rubber Production source category is the reproductive 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 threshold. See section IV.A. of this preamble for
  explanation of acute threshold values.

    The inhalation risk modeling was performed using actual emissions 
level data. As shown in Table B.2.1, the results of the revised 
inhalation risk assessment indicated the maximum lifetime individual 
cancer risk could be as high as 30-in-1 million, the maximum chronic 
non-cancer TOSHI value could be up to 0.3, and the maximum off-
facility-site acute HQ value could be as high as 1, based on the actual 
emissions level and the REL value for toluene. The total estimated 
national cancer incidence from these facilities based on actual 
emission levels is 0.003 excess cancer cases per year, or one case in 
every 333 years.
    Our analysis of potential differences between actual emission 
levels and emissions allowable under the MACT standard indicated that 
MACT-allowable emission levels are equal to actual emissions for all 
emissions sources other than back-end process operations and may be up 
to seven times greater than actual emission levels for back-end process 
operations. When these ratios of actual to MACT-allowable emissions are 
applied to each emission source type, the result is that the cancer 
risks at the MACT-allowable level are equal to those at the actual 
level shown in Table B.2.1.
    There were no reported emissions of PB-HAP; therefore, we do not 
expect potential for human health multipathway risks or adverse 
environmental impacts.
    Table B.2.2 displays the results of the facility-wide risk 
assessment. This assessment was conducted based on actual emission 
levels.

     Table B.2.2--Polybutadiene Rubber Production Facility-Wide Risk
                           Assessment Results
------------------------------------------------------------------------

------------------------------------------------------------------------
Maximum facility-wide individual cancer risk (in 1 million)..         30
    Polybutadiene Rubber Production source category                 100%
     contribution to this maximum facility-wide individual
     cancer risk) \1\........................................
Maximum facility-wide chronic non-cancer TOSHI...............        0.3
    Polybutadiene Rubber Production source category                 100%
     contribution to this maximum facility-wide non-cancer
     TOSHI \1\...............................................
------------------------------------------------------------------------
\1\ Percentage shown reflects Polybutadiene Rubber Production source
  category contribution to the maximum facility-wide risks at the
  facility with the maximum risk value shown.

    The maximum individual cancer risk from all HAP emissions at a 
facility that contains polybutadiene rubber production processes 
subject to the Group I Polymers and Resins MACT standard is estimated 
to be 30-in-1 million, and the maximum chronic non-cancer TOSHI value 
is estimated to be 0.3. At the facilities where these maximum risk 
values occur, the estimated proportion of the risk attributable to the 
Polybutadiene Rubber Production source category processes is 100 
percent for both cancer and non-cancer risk.
    The results of the demographic analyses performed to investigate 
the distribution of risks above 1-in-1 million, based on actual 
emissions levels for the population living within 5 km of the 
facilities, among various demographic groups are provided in a report 
available in the docket for this action and summarized in Table B.2.3 
below.

[[Page 65101]]

                                           Table B.2.3--Polybutadiene Rubber Demographic Risk Analysis Results
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                 Population with risk greater than 1-in-1 million
                                              Maximum   ------------------------------------------------------------------------------------------------
              Emissions basis                risk (in 1                            African    Other and    Hispanic                Below the  Over 25 W/
                                              million)      Total     Minority    American   multiracial   or Latino    Native      poverty     O a HS
                                                         (millions)       %           %           %            %      American %    level %    diploma %
--------------------------------------------------------------------------------------------------------------------------------------------------------
Nationwide................................          n/a         285          25          12           12          14         0.9          13          13
Source Category...........................           30       0.017          11           6            4           4         0.5          11          13
Facility-wide.............................           30        0.02          12           7            5           4         0.5          12          14
--------------------------------------------------------------------------------------------------------------------------------------------------------

    The results of the Polybutadiene Rubber Production source category 
demographic analysis show that the percentage of the population within 
5 km of a polybutadiene rubber production facility and with a cancer 
risk greater than 1-in-1 million is less than the distribution of these 
demographic groups across the United States as displayed in Table 
B.2.3, with the exception of those ``Over 25 Without a High School 
Diploma'', where the levels are equal to the distribution of these 
demographic groups across the United States. The table also shows that 
the facility-wide emissions demographic analysis shows similar results.
    Details of these assessments and analyses can be found in the 
residual risk documentation as referenced in section IV.A of this 
preamble, which is available in the docket for this action.
d. What are our proposed decisions on risk acceptability and ample 
margin of safety?
    October 2008 Proposed Decision. In our October 10, 2008 proposal, 
we proposed that the risks were acceptable because the risks results 
indicated that cancer risks to the individual most exposed to emissions 
from the category were 10-in-1 million which is greater than 1-in-1 
million but less than 100-in-1 million. We then analyzed other risk 
factors in the ample margin of safety determination. In this analysis, 
we proposed that emissions from the source category posed no potential 
for an adverse environmental effect, did not pose potential for human 
health multipathway risks, and were unlikely to cause acute or chronic 
non-cancer health impacts. We also identified two emissions control 
options that would reduce risks. We proposed that these controls were 
not necessary to protect public health with an ample margin of safety 
in light of the high cost and limited addition health protection they 
would provide. Therefore, we proposed that the existing standard 
provided an ample margin of safety and proposed to re-adopt the 
existing MACT standard to satisfy section 112(f) of the CAA.
    Risk Acceptability. The revised risk analysis we performed for this 
proposal indicates that the cancer risks to the individual most exposed 
is 30-in-1 million based on both actual and MACT-allowable emissions. 
The cancer incidence and the number of people exposed to cancer risks 
of 1-in-1 million or greater are not significantly changed from the 
risk identified in the October 2008 proposal. Similarly, the risk 
analysis continued to show no potential for an adverse environmental 
effect or human health multipathway effects, and that chronic non-
cancer health impacts are unlikely. The revised assessment did indicate 
that an acute non-cancer HQ as high as 1 could occur, based on the REL 
value at an area adjacent to the facility fenceline. Our additional 
analysis of facility-wide risks showed that the maximum facility-wide 
cancer risk is 30-in-1 million and that the maximum chronic non-cancer 
risks are unlikely to cause health impacts. Our additional analysis of 
the demographics of the exposed population suggests there are no 
disparities in risks for the various demographic groups. Based on this 
low cancer risk level and in consideration of other health measures and 
factors, including the low cancer incidence (one case in every 333 
years) and the low maximum non-cancer risk level (TOSHI of 0.3), we 
propose that the risks from the Polybutadiene Rubber Production source 
category are acceptable.
    Ample Margin of Safety. Because we are proposing that the risks are 
acceptable, but still above 1-in-1 million, we then re-considered our 
2008 ample margin of safety decision. We have not identified any 
additional control options or any changes to the previously analyzed 
control option. Our analysis does not indicate a change in the 
emissions reductions that could be achieved or the cost of control for 
the control option considered in the October 2008 proposal. Therefore, 
we continue to propose that the current MACT standard provides an ample 
margin of safety to protect public health and the environment, and we 
are proposing to re-adopt the existing MACT standard to satisfy section 
112(f) of the CAA.
e. What are our proposed decisions on the technology review?
    In the October 10, 2008 proposal, we identified no advancements in 
practices, processes, and control technologies applicable to the 
emission sources in the Group I Polymers and Resins Production source 
categories in our technology review, and we proposed to re-adopt the 
existing MACT standard to satisfy section 112(d)(6) of the CAA. In that 
review we examined the regulatory requirements and/or technical 
analyses for subsequently promulgated air toxics regulations with 
similar types of emissions sources as those in the Group I Polymers and 
Resins Production source categories, and we conducted a search of the 
RBLC for controls for VOC- and HAP-emitting processes in the Group I 
Polymers and Resins Production source categories. We have not 
identified any additional developments in practices, processes, and 
control technologies since the proposal date for the Polybutadiene 
Rubber Production source category. In addition, we have not identified 
the need for revisions of the standards to correct editorial errors, 
make clarifications, or address issues with implementation or 
determining compliance with the rule provisions. Thus, we are 
continuing to propose to re-adopt the existing MACT standard to satisfy 
section 112(d)(6) of the CAA.
f. What other actions are we proposing?
    The proposed changes to the SSM provisions for the Group I Polymers 
and Resins MACT, which apply to the Polybutadiene Rubber Production 
source category, are discussed above in section V.B.1.f.
3. Styrene Butadiene Rubber and Latex Production
    Styrene Butadiene Rubber and Latex Production is one of the source 
categories for which we proposed RTR decisions on October 10, 2008.

[[Page 65102]]

a. Overview of the Source Category
    Styrene butadiene rubber and latex are elastomers prepared from 
styrene and butadiene monomer units. The source category is divided 
into three subcategories due to technical process and HAP emission 
differences: (1) The production of styrene butadiene rubber by 
emulsion, (2) the production of styrene butadiene rubber by solution, 
and (3) the production of styrene butadiene latex. Styrene butadiene 
rubber is coagulated and dried to produce a solid product, while latex 
is a liquid product. For both styrene butadiene rubber processes, the 
monomers used are styrene and butadiene; either process can be 
conducted as a batch or a continuous process. These elastomers are 
commonly used in tires and tire-related products. We identified three 
currently operating styrene butadiene rubber production facilities 
using the emulsion process and three styrene butadiene rubber latex 
production facilities subject to the Polymers and Resins I MACT 
standard. Other than the polybutadiene plants that produce styrene 
butadiene rubber as a minor product, we did not identify any styrene 
butadiene rubber produced in a solution process. Some of these 
facilities are located at plant sites that also have other HAP-emitting 
sources regulated under separate MACT standards, for which we have 
addressed or will address in future rulemaking actions. Overall, 
styrene accounts for the majority of the HAP emissions from these 
facilities (approximately 276 TPY and 90 percent of the total HAP 
emissions by mass). These facilities also reported relatively small 
emissions of other HAP. The majority of HAP emissions are from back-end 
process operations (approximately 78 percent of the total HAP by mass). 
For all emission sources except the back-end process operations, the 
actual emissions level is representative of the MACT-allowable level. 
For back-end process operations, we estimate that MACT-allowable 
emissions from this source category could be as high as four times the 
actual emissions. Since these back-end limitations are production-
based, this estimate was made by comparing the actual emissions levels 
to the emissions calculated using the limitations and production 
levels. For more detail about the estimate of the ratio of actual to 
MACT-allowable emissions, see the memo in the docket for this action 
describing the estimation of MACT-allowable emission levels and 
associated risks and impacts.
b. What data were used in our risk analyses?
    We initially created a preliminary data set for the Styrene 
Butadiene Rubber and Latex Production source category using information 
we collected directly from industry on emissions data and emissions 
release characteristics. We also reviewed the emissions and other data 
to identify data anomalies that could affect risk estimates. On March 
29, 2007, we published an ANPRM (72 FR 29287) for the express purpose 
of requesting comments on and updates to this data set, as well as to 
the data sets for the other source categories addressed in that ANPRM. 
Comments received in response to the ANPRM were reviewed and 
considered, and we made adjustments to the data set where we concluded 
the comments supported such adjustment. After making appropriate 
changes to the data set based on this public data review process, the 
data set on which we based the initial proposal was created. This data 
set was used to conduct the risk assessment and other analyses for the 
Styrene Butadiene Rubber and Latex Production source category, which 
formed the basis for the proposed RTR actions included in the October 
10, 2008 proposal.
    We have continued to scrutinize the existing data set and have 
evaluated any additional data that became available subsequent to the 
October 2008 proposal. Specific questions we had concerning current 
operations led us to develop a questionnaire and ask for updated 
emissions and emissions release characteristics information. This 
information was requested from the facilities in May 2010 using the 
authority of section 114 of the CAA. We updated our data set for this 
source category based on the information received through this request.
c. What are the results of the risk assessments and analyses?
    We have conducted a revised inhalation risk assessment for the 
Styrene Butadiene Rubber and Latex Production source category. We have 
also conducted an assessment of facility-wide risk and performed a 
demographic analysis of population risks. Table B.3.1 provides an 
overall summary of the results of the revised inhalation risk 
assessment.

                                             Table B.3.1--Styrene Butadiene Rubber and Latex Production Revised Inhalation Risk Assessment Results *
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                Maximum individual cancer risk                                     Maximum chronic non-cancer TOSHI
                                                      (in 1 million) \2\          Population at    Annual cancer                  \3\
           Number of facilities \1\           ----------------------------------  risk >= 1-in-1     incidence    ----------------------------------   Maximum off-site acute non-cancer HQ \4\
                                                    Actual         Allowable         million         (cases per         Actual         Allowable
                                               emissions level  emissions level                        year)       emissions level  emissions level
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
6............................................              10               10           25,000            0.004              0.2              0.2   HQREL = 0.4 styrene.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
* All results are for impacts out to 50 km from every source in the category.
\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 Styrene Butadiene Rubber and Latex Production source category is the reproductive 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 threshold. See section IV.A. of this preamble for
  explanation of acute threshold values.

    The inhalation risk modeling was performed using actual emissions 
level data. As shown in Table B.3.1, the results of the revised 
inhalation risk assessment indicated the maximum lifetime individual 
cancer risk could be as high as 10-in-1 million, the maximum chronic 
non-cancer TOSHI value could be up to 0.2, and the maximum off-
facility-site acute HQ value could be as high as 0.4, based on the 
actual emissions level and the REL value for styrene. The total 
estimated national cancer incidence from these facilities based on 
actual emission levels is 0.004 excess cancer cases per year, or one 
case in every 250 years.
    Our analysis of potential differences between actual emission 
levels and emissions allowable under the MACT standard indicated that 
MACT-

[[Page 65103]]

allowable emission levels are equal to actual emissions for all 
emissions sources other than back-end process operations. While the 
emissions may be up to four times greater than actual emission levels 
for back-end process operations, the compounds emitted do not have 
cancer potency values so this potential increase in emissions does not 
effect risk. When these ratios of actual to MACT-allowable emissions 
are applied to each emission source type, the result is that the cancer 
risks at the MACT-allowable level are equal to those at the actual 
level shown in Table B.3.1.
    There were no reported emissions of PB-HAP; therefore, we do not 
expect potential for human health multipathway risks or adverse 
environmental impacts.
    Table B.3.2 displays the results of the facility-wide risk 
assessment. This assessment was conducted based on actual emission 
levels.

Table B.3.2--Styrene Butadiene Rubber and Latex Production Facility-Wide
                         Risk Assessment Results
------------------------------------------------------------------------

------------------------------------------------------------------------
Maximum facility-wide individual cancer risk (in 1                    70
 million).............................................
  Styrene Butadiene Rubber and Latex Production source                5%
   category contribution to this maximum facility-wide
   individual cancer risk \1\.........................
Maximum facility-wide chronic non-cancer TOSHI........                 1
  Styrene Butadiene Rubber and Latex Production source               10%
   category contribution to this maximum facility-wide
   non-cancer TOSHI \1\...............................
------------------------------------------------------------------------
\1\ Percentage shown reflects the Styrene Butadiene Rubber Production
  source category contribution to the maximum facility-wide risks at the
  facility with the maximum risk value shown.

    As shown in Table B.3.2, the maximum individual cancer risk from 
all HAP emissions at a facility that contains styrene butadiene rubber 
and latex production processes subject to the Group I Polymers and 
Resins MACT standard is estimated to be 70-in-1 million, and the 
maximum chronic non-cancer TOSHI value is estimated to be 1. At the 
facilities where these maximum risk values occur, the estimated 
proportion of the risk attributable to Styrene Butadiene Rubber and 
Latex Production source category processes is approximately 5 percent 
for cancer risks and 10 percent for chronic non-cancer risk. Both the 
cancer and non-cancer risks at this facility are primarily due to a 
nitrile butadiene rubber process, which has recently closed.
    The results of the demographic analyses performed to investigate 
the distribution of risks above 1-in-1 million, based on actual 
emissions levels for the population living within 5 km of the 
facilities, among various demographic groups are provided in a report 
available in the docket for this action and summarized in Table B.3.3 
below.

                              Table B.3.3--Styrene Butadiene Rubber and Latex Production Demographic Risk Analysis Results
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                 Population with risk greater than 1-in-1 million
                                              Maximum   ------------------------------------------------------------------------------------------------
              Emissions basis               risk  (in 1                                       Other and    Hispanic                Below the  Over 25  W/
                                              million)      Total    Minority %    African   multiracial   or Latino    Native      poverty     O a HS
                                                         (millions)              American %       %            %      American %    level %    diploma %
--------------------------------------------------------------------------------------------------------------------------------------------------------
Nationwide................................          n/a         285          25          12           12          14         0.9          13          13
Source Category...........................           10        0.02          40           3           36          54         0.6          18          24
Facility-wide.............................           70         0.1          50          29           20          32         0.5          23          20
--------------------------------------------------------------------------------------------------------------------------------------------------------

    The results of the Styrene Butadiene Rubber and Latex Production 
source category demographic analysis show that of the population with 
cancer risk greater than 1-in-1 million, 40 percent could be classified 
as a ``Minority,'' 54 percent are included in the ``Hispanic or 
Latino'' demographic group, 36 percent are included in the ``Other and 
Multiracial,'' demographic group, 18 percent are included in the 
``Below Poverty Level,'' and 24 percent are included in the ``Over 25 
Without a High School Diploma'' demographic group. These percentages of 
the population within 5 km of a styrene butadiene rubber and latex 
production facility and with a cancer risk greater than 1-in-1 million 
is higher than the percentages for these demographic categories based 
on the distribution of these demographic groups across the United 
States. The table also shows that the results of the facility-wide 
demographic analysis are higher than the national percentages for the 
those that could be classified as a ``Minority'' and for those included 
in the ``Hispanic or Latino,'' ``African American,'' ``Other and 
Multiracial,'' ``Below Poverty Level,'' and the ``Over 25 Without a 
High School Diploma'' demographic groups.
    Details of these assessments and analyses can be found in the 
residual risk documentation as referenced in section IV.A of this 
preamble, which is available in the docket for this action.
d. What are our proposed decisions on risk acceptability and ample 
margin of safety?
    October 2008 Proposed Decision. In our October 10, 2008 proposal, 
we proposed that the risks were acceptable because the risks results of 
7-in-1 million indicated that cancer risks to the individual most 
exposed to emissions from the category were greater than 1-in-1 million 
but less than 100-in-1 million. We then analyzed other risk factors in 
the ample margin of safety determination. In this analysis, we proposed 
that emissions from the source category posed no potential for an 
adverse environmental effect, did not pose potential for human health 
multipathway risks, and were unlikely to cause acute or chronic non-
cancer health impacts. We also identified one emissions control option 
that would reduce risks. We proposed that such control was not 
necessary to protect public health with an ample margin of safety in 
light of the high cost and limited addition health protection it would 
provide. Therefore, we proposed that the existing standard provided an

[[Page 65104]]

ample margin of safety and proposed to re-adopt the existing MACT 
standard to satisfy section 112(f) of the CAA.
    Risk Acceptability. The revised risk analysis we performed for this 
proposal indicates that the cancer risks to the individual most exposed 
is 10-in-1 million based on both actual and MACT-allowable emissions. 
The cancer incidence and the number of people exposed to cancer risks 
of 1-in-1 million or greater are not significantly changed from the 
risk identified in the October 2008 proposal. Similarly, the risk 
analysis continued to show no potential for an adverse environmental 
effect or human health multipathway effects, and that chronic non-
cancer health impacts are unlikely. The revised assessment indicated 
that an acute non-cancer HQ as high as 0.4 could occur, based on the 
REL value. Our additional analysis of facility-wide risks showed that 
the maximum facility-wide cancer risk is 70-in-1 million and the 
maximum facility-wide non-cancer TOSHI is 1. It also showed that the 
styrene butadiene rubber production processes located at the facilities 
with these maximum risk values contribute approximately 5 and 10 
percent to such risks, respectively. Our additional analysis of the 
demographics of the exposed population may show disparities in risks 
between demographic groups. Based on this low cancer risk level and in 
consideration of other health measures and factors, including the low 
cancer incidence (one case in every 250 years) and the low maximum non-
cancer risk level (TOSHI of 0.2), we propose that the risks from the 
Styrene Butadiene Rubber and Latex Production source category are 
acceptable.
    Ample Margin of Safety. Because we are proposing that the risks are 
acceptable, but still above 1-in-1 million, we then re-considered our 
2008 ample margin of safety decision.
    We have not identified any additional control options or any 
changes to the previously analyzed control option to reduce risks. Our 
analysis does not indicate a change in the emissions reductions that 
could be achieved or the cost of control for the control option 
considered in the October 2008 proposal. Therefore, we continue to 
propose that the current MACT standard provides an ample margin of 
safety to protect public health and the environment, and we are 
proposing to re-adopt the existing MACT standard to satisfy section 
112(f) of the CAA.
e. What are our proposed decisions on the technology review?
    In the October 10, 2008 proposal, we identified no advancements in 
practices, processes, and control technologies applicable to the 
emission sources in the Group I Polymers and Resins Production source 
categories in our technology review, and we proposed to re-adopt the 
existing MACT standard to satisfy section 112(d)(6) of the CAA. In that 
review we examined the regulatory requirements and/or technical 
analyses for subsequently promulgated air toxics regulations with 
similar types of emissions sources as those in the Group I Polymers and 
Resins I Production source categories, and we conducted a search of the 
RBLC for controls for VOC- and HAP-emitting processes in the Group I 
Polymers and Resins Production source categories. We have not 
identified any additional developments in practices, processes, and 
control technologies since the proposal date for the Styrene Butadiene 
Rubber and Latex Production source category. Thus, we are continuing to 
propose to re-adopt the existing MACT standard to satisfy section 
112(d)(6) of the CAA.
f. What other actions are we proposing?
    The proposed changes to the SSM provisions for the Group I Polymers 
and Resins MACT, which apply to the Styrene Butadiene Rubber and Latex 
Production source category, are discussed above in section V.B.1.f.
4. Nitrile Butadiene Rubber Production
    Nitrile Butadiene Rubber Production is one of the source categories 
for which we proposed RTR decisions on October 10, 2008.
a. Overview of the Source Category
    Nitrile butadiene rubber is a copolymer of 1,3-butadiene and 
acrylonitrile, and the Nitrile Butadiene Rubber Production source 
category includes any facility that polymerizes 1,3-butadiene and 
acrylonitrile. While nitrile butadiene rubber is the primary product at 
these facilities, styrene-butadiene rubber can also be produced as a 
minor product by substituting styrene for acrylonitrile as a monomer. 
Depending on its specific composition, nitrile butadiene rubber can be 
resistant to oil and chemicals, a property that facilitates its use in 
disposable gloves, hoses, seals, and a variety of automotive 
applications.
    We identified one nitrile butadiene rubber production facility 
currently subject to the Polymers and Resins I MACT standard. This 
facility is at a plant site that also has other HAP-emitting sources 
that are regulated under separate MACT standards, for which we have 
addressed or will address in future rulemaking actions. Acrylonitrile 
and 1,3-butadiene account for the HAP emissions from this source 
category (approximately 2 TPY). The majority of HAP emissions are from 
back-end process operations (approximately 97 percent of the total HAP 
by mass) for this source category. We estimate that MACT-allowable 
emissions from this source category are approximately equal to 
reported, actual emissions. For more detail about this estimate of the 
ratio of actual to MACT-allowable emissions, see the memo in the docket 
for this action describing the estimation of MACT-allowable emission 
levels and associated risks and impacts.
b. What data were used in our risk analyses?
    We initially created a preliminary data set for the Nitrile 
Butadiene Rubber Production source category using information we 
collected directly from industry on emissions data and emissions 
release characteristics. We also reviewed the emissions and other data 
to identify data anomalies that could affect risk estimates. On March 
29, 2007, we published an ANPRM (72 FR 29287) for the express purpose 
of requesting comments and updates to this data set, as well as to the 
data sets for the other source categories addressed in that ANPRM. 
Comments received in response to the ANPRM were reviewed and 
considered, and we made adjustments to the data set where we concluded 
the comments supported such adjustment. After making appropriate 
changes to the data set based on this public data review process, the 
data set on which we based the initial proposal was created. This data 
set was used to conduct the risk assessment and other analyses for the 
Nitrile Butadiene Rubber Production source category, which formed the 
basis for the proposed RTR actions included in the October 10, 2008 
proposal.
    Since the proposal, we have continued to scrutinize the existing 
data set and have evaluated any additional data that became available 
subsequent to the October 10, 2008 proposal. Specific questions we had 
concerning current operations led us to develop a questionnaire and ask 
for updated emissions and emissions release characteristics 
information. This information was requested from the facility in May 
2010 using the authority of section 114 of the CAA. We updated our data 
set for this source category based on the information received through 
this request.

[[Page 65105]]

c. What are the results of the risk assessments and analyses?
    We have conducted a revised inhalation risk assessment for the 
Nitrile Butadiene Rubber Production source category. We have also 
conducted an assessment of facility-wide risk and performed a 
demographic analysis of population risks. Table B.4.1 provides an 
overall summary of the results of the revised inhalation risk 
assessment.

                                                  Table B.4.1--Nitrile Butadiene Rubber Production Revised Inhalation Risk Assessment Results *
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                Maximum individual cancer risk                                        Maximum chronic non-cancer
                                                      (in 1 million) \2\                           Annual cancer               TOSHI \3\
                                              ----------------------------------  Population at      incidence    ----------------------------------
           Number of facilities \1\                 Actual         Allowable      risk >= 1-in-1     (cases per         Actual         Allowable       Maximum off-site acute non-cancer HQ \4\
                                                  emissions        emissions         million           year)          emissions        emissions
                                                    level            level                                              level            level
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
1............................................               2                2               70           0.0004            0.009            0.009   HQAEGL	1 = 0.002 acrylonitrile
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
* All results are for impacts out to 50 km from every source in the category.
\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 Nitrile Butadiene Rubber Production source category is the reproductive 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 threshold. See section III.A of this preamble for
  explanation of acute threshold values.

    The inhalation risk modeling was performed using actual emissions 
level data. As shown in Table B.4.1, the results of the revised 
inhalation risk assessment indicated the maximum lifetime individual 
cancer risk could be as high as 2-in-1 million, the maximum chronic 
non-cancer TOSHI value could be up to 0.009, and the maximum off-
facility-site acute HQ value could be as high as 0.002, based on the 
actual emissions level and the AEGL-1 value for acrylonitrile. The 
total estimated national cancer incidence from these facilities based 
on actual emission levels is 0.0004 excess cancer cases per year, or 
one case in every 2,500 years.
    Our analysis of potential differences between actual emission 
levels and emissions allowable under the MACT standard indicate that 
actual and allowable emissions are approximately the same. Therefore, 
the risk results for MACT-allowable emissions are equal to those for 
actual emissions.
    There were no reported emissions of PB-HAP; therefore, we do not 
expect potential for human health multipathway risks or adverse 
environmental impacts.
    Table B.4.2 displays the results of the facility-wide risk 
assessment. This assessment was conducted based on actual emission 
levels.

   Table B.4.2--Nitrile Butadiene Rubber Production Facility-Wide Risk
                           Assessment Results
------------------------------------------------------------------------

------------------------------------------------------------------------
Maximum facility-wide individual cancer risk (in 1                     5
 million).............................................
    Nitrile Butadiene Rubber Production source                       33%
     category contribution to this maximum facility-
     wide individual cancer risk \1\..................
Maximum facility-wide chronic non-cancer TOSHI........              0.03
    Nitrile Butadiene Rubber Production source                       30%
     category contribution to this maximum facility-
     wide non-cancer TOSHI \1\........................
------------------------------------------------------------------------
\1\ Percentage shown reflects Nitrile Butadiene Rubber Production source
  category contribution to the maximum facility-wide risks at the
  facility with the maximum risk value shown.

    The maximum individual cancer risk from all HAP emissions at a 
facility that contains nitrile butadiene rubber production processes 
subject to the Group I Polymers and Resins MACT standard is estimated 
to be 5-in-1 million, and the maximum chronic non-cancer TOSHI value is 
estimated to be 0.03. The estimated proportion of the risk attributable 
to Nitrile Butadiene Rubber Production source category processes at 
this facility is approximately 33 percent for cancer risks and 30 
percent for chronic non-cancer risk. This facility also has processes 
subject to the Group IV Polymers and Resins MACT standard, 40 CFR part 
63, subpart JJJ.
    The results of the demographic analyses performed to investigate 
the distribution of risks above 1-in-1 million, based on actual 
emissions levels for the population living within 5 km of the 
facilities, among various demographic groups are provided in a report 
available in the docket for this action and summarized in Table B.4.3 
below.

                                   Table B.4.3--Nitrile Butadiene Rubber Production Demographic Risk Analysis Results
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                 Population with risk greater than 1-in-1 million
                                              Maximum   ------------------------------------------------------------------------------------------------
             Emissions  basis               risk  (in 1                                       Other and    Hispanic                Below the  Over 25 W/
                                              million)      Total    Minority %    African   multiracial   or Latino    Native      poverty     O a HS
                                                         (millions)              American %       %            %      American %    level %    diploma %
--------------------------------------------------------------------------------------------------------------------------------------------------------
Nationwide................................          n/a         285          25          12           12          14         0.9          13          13
Source Category...........................            2     0.00007          94          94            0           0           0          33          14
Facility-wide.............................            5       0.006          95          93            2         0.4         0.1          23          17
--------------------------------------------------------------------------------------------------------------------------------------------------------

[[Page 65106]]

    The results of the demographic analysis show that, for the Nitrile 
Butadiene Rubber Production source category, of the population of 70 
people with cancer risk greater than 1-in-1 million, 94 percent could 
be classified as a ``Minority,'' 94 percent are included in the 
``African-American'' demographic group, 33 percent are included in the 
``Below Poverty Level'' demographic group, and 14 percent are included 
in the ``Over 25 Without a High School Diploma'' demographic group. The 
percentage of the population for these demographic categories within 5 
km of a nitrile butadiene rubber production facility and with a cancer 
risk greater than 1-in-1 million is higher than distribution of these 
demographic groups across the United States. The table also shows that 
the results of the demographic analysis for the 6,000 people at cancer 
risk greater than 1-in-1 million from facility-wide emissions are 
similar to the results for the source category.
    Details of these assessments and analyses can be found in the 
residual risk documentation as referenced in section IV.A of this 
preamble, which is available in the docket for this action.
d. What are our proposed decisions on risk acceptability and ample 
margin of safety?
    October 2008 Proposed Decision. In our October 2008 proposal, we 
proposed that the risks were acceptable because the risks results 
indicated that cancer risks to the individual most exposed to emissions 
from the category of 60-in-1 million were greater than 1-in-1 million 
but less than 100-in-1 million. We then analyzed other risk factors in 
the ample margin of safety determination. In this analysis, we proposed 
that emissions from the source category posed no potential for an 
adverse environmental effect, did not pose potential for human health 
multipathway risks, and were unlikely to cause acute or chronic non-
cancer health impacts. We also identified one emissions control option 
that would reduce risks. We proposed that such control was not 
necessary to protect public health with an ample margin of safety in 
light of the high cost and limited addition health protection it would 
provide. Therefore, we proposed that the existing standard provided an 
ample margin of safety and proposed to re-adopt the existing MACT 
standard to satisfy section 112(f) of the CAA.
    Risk Acceptability. The revised risk analysis we performed for this 
proposal indicates that the cancer risks to the individual most exposed 
is 2-in-1 million based on both actual and MACT-allowable emissions. 
The cancer incidence and the number of people exposed to cancer risks 
of 1-in-1 million or greater are much less than the risk identified in 
the October 2008 proposal. Similarly, the risk analysis continued to 
show no potential for an adverse environmental effect or human health 
multipathway effects, and that acute or chronic non-cancer health 
impacts are unlikely. Our additional analysis of facility-wide risks 
showed that the maximum facility-wide cancer risk is 5-in-1 million and 
that the maximum chronic non-cancer risks are unlikely to cause health 
impacts. Our additional analysis of the demographics of the exposed 
population may show disparities in risks between demographic groups, 
but only for the 60 people at cancer risk greater than 1-in-1 million. 
Based on this low cancer risk level and in consideration of other 
health measures and factors, including the low cancer incidence (one 
case in every 2,500 years) and the low maximum non-cancer risk level 
(TOSHI of 0.009), we propose that the risks from the Nitrile Butadiene 
Rubber Production source category are acceptable.
    Ample Margin of Safety. Because we are proposing that the risks are 
acceptable, but still above 1-in-1 million, we then re-considered our 
October 2008 ample margin of safety decision.
    We have not identified any additional control options or any 
changes to the previously analyzed control option. Our analysis does 
not indicate a change in the emissions reductions that could be 
achieved or the cost of control for the control option considered in 
the October 2008 proposal. Therefore, we continue to propose that the 
current MACT standard provides an ample margin of safety to protect 
public health and the environment, and we are proposing to re-adopt the 
existing MACT standard to satisfy section 112(f) of the CAA.
e. What are our proposed decisions on the technology review?
    In the October 10, 2008 proposal, we identified no advancements in 
practices, processes, and control technologies applicable to the 
emission sources in the Group I Polymers and Resins Production source 
categories in our technology review, and we proposed to re-adopt the 
existing MACT standard to satisfy section 112(d)(6) of the CAA. In that 
review we examined the regulatory requirements and/or technical 
analyses for subsequently promulgated air toxics regulations with 
similar types of emissions sources as those in the Group I Polymers and 
Resins Production source categories, and we conducted a search of the 
RBLC for controls for VOC- and HAP-emitting processes in the Group I 
Polymers and Resins Production source categories. We have not 
identified any additional developments in practices, processes, and 
control technologies since the proposal date for the Nitrile Butadiene 
Rubber Production source category. Thus, we are continuing to propose 
to re-adopt the existing MACT standard to satisfy section 112(d)(6) of 
the CAA.
f. What other actions are we proposing?
    SSM Provisions. The proposed changes to the Group I Polymers and 
Resins MACT, which apply to the Nitrile Butadiene Rubber Production 
source category, are discussed above in section V.B.1.f.
    Significant Emission Points Not Previously Regulated. We identified 
the absence of a standard for a significant emissions source in the 
category in the provisions of the Group I Polymers and Resins MACT 
standard that apply to the Nitrile Butadiene Rubber Production source 
category. Specifically, there are no back-end process operation 
emission limits for this source category.\36\ As these processes are 
major sources of emissions for the one facility in the source category, 
we are proposing to set standards for back-end process operations under 
CAA section 112(d)(2) and (d)(3) in this action.
---------------------------------------------------------------------------

    \36\ Note that these uncontrolled emissions were included in the 
baseline risk assessment.
---------------------------------------------------------------------------

    The emission limit we are proposing today represents the MACT floor 
level of control. As there is only one facility in the source category, 
the emissions limitation achieved by this facility is the MACT floor. 
The annual emissions from the back-end process operations at this 
facility are approximately 2 TPY. There are 11 separate dryer vents; 
one is controlled, while the others are uncontrolled. The controlled 
vent emits around 0.003 TPY of 1,3-butadiene and 0.002 TPY of 
acrylonitrile. The regenerative thermal oxidizer used on this vent 
achieves approximately 96 percent control of the acrylonitrile 
emissions, but no control of 1,3-butadiene. The collection of 10 
uncontrolled vents emit around 0.8 TPY of 1,3-butadiene and 0.9 TPY of 
acrylonitrile.
    As part of our beyond-the-floor analysis, we considered 
alternatives more stringent than the MACT floor option. We identified 
one option using add-on emission controls that would require the 
ducting of emissions from the currently uncontrolled back-end process 
operations emission source to a control device, such as an incinerator.

[[Page 65107]]

This option would also require an initial performance test of the 
incinerator and continuous parameter monitoring averaged daily. The 
capital costs of this option are estimated to be approximately 
$1,600,000 and the total annual costs are estimated to be approximately 
$11,400,000/year. We estimate that an incinerator would achieve an 
emissions reduction of 98 percent, resulting in a HAP decrease of 
approximately 1.7 TPY, with a cost-effectiveness of approximately 
$6,700,000/ton. Table B.4.4 summarizes the cost and emission reduction 
impacts of the proposed options.

                Table B.4.4--Nitrile Butadiene Rubber Production Facility Back-End Option Impacts
----------------------------------------------------------------------------------------------------------------
                                                                                                      Cost-
                                                                                                effectiveness as
                                            HAP emissions     Capital cost       Annual cost       compared to
         Regulatory alternatives                (TPY)          (million $)     (million $/yr)       baseline
                                                                                                 (million $/ton
                                                                                                  HAP removed)
----------------------------------------------------------------------------------------------------------------
Baseline................................               1.7  ................  ................  ................
1 (MACT floor)..........................               1.7                 0                 0  ................
2 (Beyond-the-floor)....................              0.04               1.6              11.4               6.7
----------------------------------------------------------------------------------------------------------------

    In addition to the cost and emission reduction impacts shown in 
Table B.4.4, we estimate that the beyond-the-floor option will result 
in increases in criteria pollutant and carbon dioxide emissions (PM-2 
TPY, SO2-0.4 TPY, NOX-133 TPY, CO-23 TPY, and 
CO2-80,000 TPY) and an increase in energy use of 
approximately 1,400,000 BTU/year at a cost of approximately $385,000/
year.
    We believe that the costs and other impacts of this beyond-the-
floor option are not reasonable, given the level of emission reduction. 
Therefore, we are proposing Option 1, the MACT floor option. We are 
requesting comment on this analysis and these options.
    As noted above, we are proposing that the MACT standard, prior to 
the implementation of the proposed emission limitation to the back-end 
process operations discussed in this section, provides an ample margin 
of safety to protect public health. Since the proposed emission 
limitation represents the existing level of control for the single 
plant in the source category, this proposed emission limitation will 
not have an impact on risk. Therefore, we maintain that after its 
implementation, the rule will continue to provide an ample margin of 
safety to protect public health. Consequently, we do not believe it 
will be necessary to conduct another residual risk review under CAA 
section 112(f) for this source category 8 years following promulgation 
of new back-end process limitations, merely due to the addition of this 
new MACT requirement.
5. Neoprene Rubber Production
    Neoprene Rubber Production is one of the source categories for 
which we proposed and finalized RTR decisions on December 12, 2007 (72 
FR 70543) and December 16, 2008 (73 FR 76220), respectively.
a. Overview of the Source Category
    Neoprene is a polymer of chloroprene. Neoprene was originally 
developed as an oil-resistant substitute for natural rubber, and its 
properties allow its use in a wide variety of applications, including 
wetsuits, gaskets and seals, hoses and tubing, plumbing fixtures, 
adhesives, and other products. We have identified one neoprene rubber 
production facility currently subject to the Polymers and Resins I MACT 
standards.
    For the Neoprene Rubber Production source category, we have 
proposed and finalized a decision not to revise the standards for those 
source categories based on our RTR. As noted above, this decision was 
proposed on December 12, 2007 and finalized on December 16, 2008. Since 
the Neoprene Production source category was determined to be ``low 
risk'' (maximum lifetime cancer risk less than 1-in-1 million), we did 
not believe it was necessary to conduct a facility-wide or demographic 
risk analysis. Therefore, we are not addressing the RTR in today's 
notice for this source category.
b. What other actions are we proposing?
    SSM Provisions. The proposed changes to the Group I Polymers and 
Resins MACT, which apply to the Neoprene Rubber Production source 
category, are discussed above in section V.B.1.f.
    Significant Emission Points Not Previously Regulated. We identified 
in the provisions of the Group I Polymers and Resins MACT standard that 
apply to the Neoprene Rubber Production source category the absence of 
a standard for a significant emissions source in the category. 
Specifically, there are no back-end process operation emission limits 
for this source category. As these processes are major sources of 
emissions for the one facility in the source category, we are proposing 
to set standards for back-end process operations under CAA sections 
112(d)(2) and (3) in this action.
    As there is only one facility in the source category, the emissions 
level currently being achieved by this facility represents the MACT 
floor. The annual emissions from the back-end process operations at 
this facility are approximately 14 TPY. There are 11 separate dryer 
vents collectively emitting around 14 TPY of toluene. None of the vents 
are controlled. Therefore, we have determined that the MACT floor for 
the back-end process is 14 TPY based on stripping and HAP recovery, 
given current production levels, but which would fluctuate 
proportionally with an increase or decrease in production levels.
    As part of our beyond-the-floor analysis, we considered 
alternatives more stringent than the MACT floor option. We identified 
one option using add-on emission controls that would require the 
ducting of emissions from the back-end process operations to a control 
device, such as an incinerator. This option would also require an 
initial performance test of the incinerator and continuous parameter 
monitoring averaged daily. The capital costs of this option are 
estimated to be approximately $1,300,000 and the total annual costs are 
estimated approximately $4,800,000 per year. We estimate that an 
incinerator would achieve an emissions reduction of 98 percent, 
resulting in a HAP decrease of approximately 22.6 TPY, with a cost-
effectiveness of approximately $213,000 per ton. Table B.5.1 summarizes 
the impacts of the proposed options.

[[Page 65108]]

                    Table B.5.1--Neoprene Rubber Production Facility Back-End Option Impacts
----------------------------------------------------------------------------------------------------------------
                                                                                                      Cost-
                                                                                                effectiveness as
         Regulatory alternatives           HAP  emissions     Capital cost       Annual cost       compared to
                                                (TPY)          (million $)      (million$/yr)    baseline ($/ton
                                                                                                  HAP removed)
----------------------------------------------------------------------------------------------------------------
Baseline................................                23  ................  ................  ................
1 (MACT floor)..........................                23                 0                 0  ................
2 (Beyond-the-floor)....................               0.5               1.3               4.8           213,000
----------------------------------------------------------------------------------------------------------------

    In addition to the cost and emission reduction impacts shown in 
Table B.5.1, we estimate that the beyond-the-floor option will result 
in increases in criteria pollutant and carbon dioxide emissions (PM - 
0.8, SO2 - 0.2 TPY, NOX - 55 TPY, CO - 10 TPY, 
and CO2 - 33,000 TPY) and an increase in energy use of 
approximately 560,000 million BTU/year at a cost of approximately 
$159,000/year.
    We believe that the costs and other impacts of this beyond-the-
floor option are not reasonable, given the level of emission reduction. 
Therefore, we are proposing Option 1, the MACT floor option. We are 
requesting comment on this analysis and these options.
    As noted above, we have proposed and finalized a decision that the 
MACT standard for neoprene rubber production, prior to the 
implementation of the proposed emission limitation to the back-end 
process operations discussed in this section, provides an ample margin 
of safety to protect public health. Since this source category was 
``low risk'' prior to this proposed emission limitation, we maintain 
that after their implementation, the rule will continue to provide an 
ample margin of safety to protect public health. Consequently, we do 
not believe it will be necessary to conduct another residual risk 
review under CAA section 112(f) for this source category 8 years 
following promulgation of new back-end process limitations, merely due 
to the addition of this new MACT requirement.
6. Ethylene Propylene Rubber Production
    Ethylene Propylene Rubber Production is one of the source 
categories for which we proposed and finalized RTR decisions on 
December 12, 2007 (72 FR 70543) and December 16, 2008 (73 FR 76220), 
respectively.
a. Overview of the Source Category
    Ethylene propylene rubber is an elastomer prepared from ethylene 
and propylene monomers. Common uses for these elastomers include 
radiator and heater hoses, weather stripping, door and window seals for 
cars, construction plastics blending, wire and cable insulation and 
jackets, and single-ply roofing membranes.
    For the Ethylene Propylene Rubber Production source category, we 
have proposed and finalized a decision not to revise the standards for 
this source category based on our RTR. As noted above, this decision 
was proposed on December 12, 2007 and finalized on December 16, 2008. 
Since the Ethylene Propylene Rubber Production source category was 
determined to be ``low risk'' (maximum lifetime cancer risk less than 
1-in-1 million), we did not believe it was necessary to conduct a 
facility-wide or demographic risk analysis. Therefore, we are not 
addressing the RTR in this notice for this source category.
b. What other actions are we proposing?
    SSM Provisions. The proposed changes to the SSM provisions for the 
Group I Polymers and Resins MACT, which apply to the Ethylene Propylene 
Rubber Production source category, are discussed above in section 
V.B.1.f.
    Significant Emission Points Not Previously Regulated. We identified 
in the provisions of the Group I Polymers and Resins MACT standard that 
apply to the Ethylene Propylene Rubber Production source category the 
absence of a standard for a significant emissions source in the 
category. Specifically, the rule requires that emissions from Group 1 
front-end process vents be routed to a control device that achieves 98 
percent reduction in organic HAP emissions but does not require the 
control of hydrogen halides and halogens from the outlet of combustion 
devices. All three currently-operating facilities in this source 
category control the organic HAP emissions in accordance with the 
requirements in the rule (i.e., reduce organic HAP emissions by 98 
percent). This represents the MACT floor for this source category. 
However, one facility routes a chlorinated organic compound to a flare, 
which results in emissions of HCl that are not regulated by the current 
MACT requirements. When chlorinate organics are burned in a flare, 
there are variations in the combustion which likely results in the 
formation of combustion by-products. These combustion by-products could 
include trace chlorinated compounds such as dioxins and furans. Due to 
the level of HCl emissions resulting from the combustion of chlorinated 
organic compounds in Group 1 streams, we are proposing to require 
control of these HCl emissions for the Ethylene Propylene Rubber 
Production source category.
    As part of our beyond-the-floor analysis, we considered 
alternatives to reduce these HCl emissions, which are more stringent 
than the MACT floor option. We identified the option of eliminating the 
exemption from the requirement to control hydrogen halides and halogens 
from the outlet of combustion devices. The one facility reports around 
20 TPY of HCl emissions resulting from the combustion of chlorinated 
organic compounds in a flare. The other two facilities indicated that 
they do not emit any HCl emissions resulting from the combustion of 
chlorinated organic compounds. We estimated that the capital costs for 
the facility to replace the flare with an incinerator followed by a 
scrubber to reduce the HCl would be approximately $985,000 and the 
total annual costs are estimated to be approximately $446,000 per year. 
While there would be no additional reduction in organic HAP from this 
requirement, the HCl emissions would be reduced by 99 percent, or 19.6 
TPY. The cost-effectiveness of this option would be approximately 
$21,000 per ton. However, this ethylene propylene rubber process is co-
located with the halobutyl rubber process, which also vents a vent 
stream containing chlorinated organic compounds to a flare, resulting 
in HCl emissions. We estimated the costs of a single incinerator and 
scrubber to control the streams containing chlorinated organics from 
both the ethylene propylene rubber and halobutyl rubber processes. The 
estimated capital cost of this control scenario is $1,100,000 and the 
annual cost is $640,000 per year. This would still achieve the same HCl 
emission reduction from the ethylene propylene

[[Page 65109]]

rubber process (19.6 TPY), and the overall cost-effectiveness 
considering the reductions from the ethylene propylene rubber and 
halobutyl rubber would be around $6,700 per ton. Table B.6.1 summarizes 
the impacts of the proposed options.

              Table B.6.1--Ethylene Propylene Rubber Production Facility Front-End Options Impacts
----------------------------------------------------------------------------------------------------------------
                                                                                                      Cost-
                                                                                                effectiveness as
         Regulatory alternatives            HAP emissions     Capital cost       Annual cost       compared to
                                              (TPY HAP)        ($million)       ($million/yr)    baseline ($/ton
                                                                                                  HAP  removed)
----------------------------------------------------------------------------------------------------------------
Baseline................................                20  ................  ................  ................
1 (MACT floor)..........................                20                 0                 0  ................
2 (Beyond-the-floor)....................               0.2             * 1.1             * 0.6           * 6,700
----------------------------------------------------------------------------------------------------------------
* Assuming a shared control incinerator/scrubber combination is used for both the ethylene propylene rubber and
  halobutyl rubber processes.

    In addition to the cost and emission reduction impacts shown in 
Table B.6.1, we estimate that the beyond-the-floor option will result 
in increases in criteria pollutant and carbon dioxide emissions (PM - 
0.03 TPY, SO2 - 0.006 TPY, NOX - 2 TPY, CO - 0.4 
TPY, and CO2 - 1,200 TPY), the generation of approximately 
29 million gallons/year of wastewater, and an increase in energy use of 
approximately 21,000 million BTU/year at a cost of approximately 
$7,000/year.
    We believe that the costs and other impacts of this beyond-the-
floor option are reasonable, given the level of emission reduction. 
Therefore, we are proposing Option 2, the beyond-the-floor option. We 
are requesting comment on this analysis and these options.
    As noted above, we have proposed and finalized a decision that the 
MACT standard for ethylene propylene rubber production, prior to the 
implementation of the proposed emission limitation discussed in this 
section, provides an ample margin of safety to protect public health. 
Since this source category was ``low risk'' prior to this proposed 
emission limitation, we maintain that after its implementation, which 
will only further reduce HAP emissions, the rule will continue to 
provide an ample margin of safety to protect public health. 
Consequently, we do not believe it will be necessary to conduct another 
residual risk review under CAA section 112(f) for this source category 
8 years following promulgation of new limitations, merely due to the 
addition of this new MACT requirement.
7. Butyl Rubber Production
    Butyl Rubber Production is one of the source categories for which 
we proposed and finalized RTR decisions on December 12, 2007 (72 FR 
70543) and December 16, 2008 (73 FR 76220), respectively.
a. Overview of the Source Category
    The Butyl Rubber Production source category includes any facility 
that manufactures copolymers of isobutylene and isoprene. A typical 
composition of butyl rubber is approximately 97 percent isobutylene and 
3 percent isoprene. Modified, derivative, and halogenated copolymers 
and latexes are also included in this source category. Butyl rubber is 
typically made by a precipitation (slurry) polymerization process in 
which isobutylene and isoprene are copolymerized in methyl chloride 
solvent. Butyl rubber is very impermeable to common gases and resists 
oxidation. Uses for butyl rubber include tires, tubes, and tire 
products; automotive mechanical goods; adhesives, caulks, and sealants; 
and pharmaceutical uses. A specialty group of butyl rubbers are 
halogenated butyl rubbers, which are produced commercially by 
dissolving butyl rubber in hydrocarbon solvent and contacting the 
solution with gaseous or liquid elemental halogens such as chlorine or 
bromine. For the purpose of the MACT standards, this source category is 
divided into two subcategories: butyl rubber and halobutyl rubber.
    For the Butyl Rubber Production source category, we have proposed 
and finalized a decision not to revise the standards for this source 
category based on our RTR. As noted above, this decision was proposed 
on December 12, 2007 and finalized on December 16, 2008. Since the 
Butyl Rubber Production source category was determined to be ``low 
risk'' (maximum lifetime cancer risk less than 1-in-1 million), we did 
not believe it was necessary to conduct a facility-wide or demographic 
risk analysis. Therefore, we are not addressing the RTR in this notice 
for this source category.
b. What other actions are we proposing?
    SSM Provisions. The proposed SSM changes to the Group I Polymers 
and Resins MACT, which apply to the Butyl Rubber Production source 
category, are discussed above in section V.B.1.f.
    Significant Emission Points Not Previously Regulated. We identified 
in the provisions of the Group I Polymers and Resins MACT standard that 
apply to both Butyl Rubber Production subcategories the absence of 
standards for two significant emissions sources in each of the Butyl 
Rubber Production subcategories. Specifically, these situations are HCl 
emissions from front-end process vents and emissions from back-end 
process operations.
    The rule requires that emissions from Group 1 front-end process 
vents be routed to a control device that achieves 98 percent reduction 
in organic HAP emissions but does not require the control of hydrogen 
halides and halogens from the outlet of combustion devices. Both 
facilities in these subcategories control the organic HAP emissions in 
accordance with the requirements in the rule (i.e., reduce organic HAP 
emissions by 98 percent). This represents the MACT floor for these 
subcategories. However, these facilities route a chlorinated organic 
compound to a flare, which results in emissions of HCl that are 
exempted from the current MACT requirements. Due to the level of HCl 
emissions resulting from the combustion of chlorinated organic 
compounds in Group 1 streams, we are proposing to require control of 
these HCl emissions for both the Butyl Rubber Production and Halobutyl 
Rubber Production subcategories.
    As there is only one facility in each subcategory, the existing 
level of control for organic HAP emissions represents the MACT floor. 
As part of our beyond-the-floor analysis, we considered alternatives to 
reduce the HCl emissions, which are more stringent than the MACT floor 
option. For front-end process vents, we identified the option of 
eliminating the exemption

[[Page 65110]]

from the requirement to control hydrogen halides and halogens from the 
outlet of combustion devices. The butyl rubber facility reported HCl 
emissions of 30.1 TPY, while the halobutyl rubber facility reported 
76.8 TPY. Since scrubbers could not be installed on the outlet of these 
combustion devices to reduce the HCl emissions by 99 percent, the butyl 
rubber facility and the halobutyl rubber facility would need to install 
new incinerators followed by scrubbers to comply with this beyond-the-
floor requirement. We estimate that the capital costs for this would be 
$669,000 for the butyl rubber facility and $984,000 for the halobutyl 
rubber facility. The total annual costs would be around $235,000 per 
year for the butyl rubber facility and $424,000 per year for the 
halobutyl rubber facility. Since there would be no additional reduction 
in organic HAP emissions from what is being achieved by the current 
controls, the only emission reduction would a 99 percent reduction in 
HCl emissions, or 29.8 TPY for the butyl rubber facility and 76 TPY for 
the halobutyl rubber facility. Thus, the cost-effectiveness of these 
beyond-the-floor options would be approximately $7,900 per ton for 
butyl rubber and $6,000 per ton for halobutyl rubber. However, this 
halobutyl rubber process is co-located with an ethylene propylene 
rubber process, which also vents a vent stream containing chlorinated 
organic compounds to a flare, resulting in HCl emissions. As these 
streams could be controlled using the same equipment at this facility, 
we estimated the costs of a single incinerator and scrubber to control 
the streams containing chlorinated organics from both the ethylene 
propylene rubber and halobutyl rubber processes. The estimated capital 
cost of this control scenario is $1,100,000 and the annual cost is 
$640,000 per year. This would still achieve the same HCl emission 
reduction from the halobutyl rubber process (76 TPY), and the overall 
cost-effectiveness considering the reductions from the ethylene 
propylene rubber and halobutyl rubber would be around $6,700 per ton. 
Tables B.7.1 and B.7.2 summarize the impacts of the proposed options.

                     Table B.7.1--Butyl Rubber Production Facility Front-End Options Impacts
----------------------------------------------------------------------------------------------------------------
                                                                                                      Cost-
                                                     HAP                                        effectiveness as
            Regulatory alternatives               emissions    Capital cost      Annual cost       compared to
                                                  (TPY HAP)     ($million)      ($million/yr)    baseline ($/ton
                                                                                                  HAP removed)
----------------------------------------------------------------------------------------------------------------
Baseline.......................................         30.1  ..............  ................  ................
1 (MACT floor).................................         30.1               0                 0  ................
2 (Beyond-the-floor)...........................          0.3             0.6               0.2            $7,900
----------------------------------------------------------------------------------------------------------------

                   Table B.7.2--Halobutyl Rubber Production Facility Front-End Options Impacts
----------------------------------------------------------------------------------------------------------------
                                                                                                      Cost-
                                                                                                effectiveness as
         Regulatory alternatives           HAP  emissions     Capital cost       Annual cost       compared to
                                              (TPY HAP)        ($million)       ($million/yr)    baseline ($/ton
                                                                                                  HAP removed)
----------------------------------------------------------------------------------------------------------------
Baseline................................              76.8  ................  ................  ................
1 (MACT floor)..........................              76.8                 0                 0  ................
2 (Beyond-the-floor)....................               0.8             * 1.1             * 0.6          * $6,700
----------------------------------------------------------------------------------------------------------------
* Assuming a shared control incinerator/scrubber combination is used for both the ethylene propylene rubber and
  halobutyl rubber processes.

    In addition to the cost and emission reduction impacts shown in 
Table B.7.1 for butyl rubber production, we estimate that the beyond-
the-floor option will result in increases in criteria pollutant and 
carbon dioxide emissions (PM - 0.004 TPY, SO2 - 0.001 TPY, 
NOX - 2 TPY, CO - 0.05 TPY, and CO2 - 160 TPY), 
the generation of approximately 31 million gallons/year of wastewater, 
and an increase in energy use of around 3,000 million BTU/year at a 
cost of approximately $3,000/year.
    In addition to the cost and emission reduction impacts shown in 
Table B.6.2 for halobutyl rubber production, we estimate that the 
beyond-the-floor option will result in increases in criteria pollutant 
and carbon dioxide emissions (PM - 0.03 TPY, SO2 - 0.006 
TPY, NOX - 2 TPY, CO - 0.4 TPY, and CO2 - 1,200 
TPY), the generation of approximately 29 million gallons/year of 
wastewater, and an increase in energy use of around 21,000 million BTU/
year at a cost of approximately $7,000/year.
    We believe that the costs and other impacts of these beyond-the-
floor options are reasonable, given the level of emission reduction. 
Therefore, we are proposing Option 2, the beyond-the-floor option, for 
both the Butyl Rubber Production and Halobutyl Rubber Production 
subcategories. We are requesting comment on this analysis and these 
options.
    We also noted that there are no back-end process operation emission 
limits for either the Butyl Rubber Production or Halobutyl Rubber 
Production subcategories. As there is only one facility in each 
subcategory, the back-end process operations emissions level currently 
being achieved by these facilities represents the MACT floor. The 
annual emissions from the uncontrolled back-end process operations at 
the butyl rubber facility are approximately 26 TPY, and 35 TPY at the 
halobutyl facility. There are two separate dryer vent streams at the 
butyl rubber facility, with one stream controlled. The controlled 
stream emits around 28 TPY of hexane. The regenerative thermal oxidizer 
used to control emissions achieves approximately 98-percent control. 
There are four separate dryer vents at the halobutyl facility and one 
vent is controlled. The controlled vent emits around 18 TPY of hexane. 
The regenerative thermal oxidizer used to control emissions achieves 
approximately 97-percent control of the hexane emissions. The four 
uncontrolled vents collectively emit around 35 TPY of hexane. 
Therefore, we have determined that the MACT floors

[[Page 65111]]

for these processes are these emission levels, given current production 
levels, but which would fluctuate proportionally with an increase or 
decrease in production levels.
    As part of our beyond-the-floor analysis, we considered 
alternatives more stringent than the MACT floor option. We identified 
one option using add-on emission controls that would require the 
ducting of emissions from the uncontrolled back-end process operations 
to a control device, such as an incinerator. This option would also 
require an initial performance test of the incinerator and continuous 
parameter monitoring averaged daily. For the Butyl Rubber Production 
subcategory, the capital costs of this option are estimated to be 
approximately $235,000 and the total annual costs are estimated to be 
approximately $181,000. For the Halobutyl Rubber Production 
subcategory, the capital costs of this option are estimated to be 
approximately $950,000 and the total annual costs are estimated to be 
approximately $1,600,000 per year. We estimate that an incinerator 
would achieve an emissions reduction of 98 percent, resulting in a HAP 
decrease of approximately 26 TPY for the Butyl Rubber Production 
subcategory and 34 for Halobutyl Rubber Production subcategory. The 
associated cost-effectiveness values would be approximately $7,000 per 
ton for Butyl Rubber Production subcategory and $47,000/ton for 
Halobutyl Rubber Production subcategory. Tables B.7.3 and B.7.4 
summarize the impacts of the proposed options.

                Table B.7.3--Butyl Rubber Production Subcategory Facility Back-End Option Impacts
----------------------------------------------------------------------------------------------------------------
                                                                                                      Cost-
                                                                                                effectiveness as
        Regulatory alternatives           HAP emissions      Capital cost       Annual cost        compared to
                                            (TPY HAP)         ($million)       ($million/yr)     baseline ($/ton
                                                                                                  HAP removed)
----------------------------------------------------------------------------------------------------------------
Baseline..............................                54  .................  .................  ................
1 (MACT floor)........................                54                0                  0    ................
2 (Beyond-the-floor)..................                28                0.2                0.2            $7,000
----------------------------------------------------------------------------------------------------------------

              Table B.7.4--Halobutyl Rubber Production Subcategory Facility Back-End Option Impacts
----------------------------------------------------------------------------------------------------------------
                                                                                                      Cost-
                                                     HAP                                        effectiveness as
            Regulatory alternatives               Emissions    Capital cost      Annual cost       compared to
                                                  (TPY HAP)     ($million)      ($million/yr)    baseline ($/ton
                                                                                                  HAP removed)
----------------------------------------------------------------------------------------------------------------
Baseline.......................................           53  ..............  ................  ................
1 (MACT floor).................................           53               0                 0  ................
2 (Beyond-the-floor)...........................           19               1               1.6           $47,000
----------------------------------------------------------------------------------------------------------------

    In addition to the cost and emission reduction impacts shown in 
Table B.7.3 for Butyl Rubber Production subcategory, we estimate that 
the beyond-the-floor option will result in increases in criteria 
pollutant and carbon dioxide emissions (PM - 0.01, SO2 - 
0.003 TPY, NOX - 8 TPY, CO - 0.2 TPY, and CO2 - 
600 TPY) and an increase in energy use of approximately 10,000 million 
BTU/year at a cost of approximately $6,000/year.
    In addition to the cost and emission reduction impacts shown in 
Table B.7.4 for Halobutyl Rubber Production subcategory, we estimate 
that the beyond-the-floor option will result in increases in criteria 
pollutant and carbon dioxide emissions (PM -0.25, SO2 -0.05 
TPY, NOX -17 TPY, CO -3 TPY, and CO2 -10,500 TPY) 
and an increase in energy use of approximately 170,000 million BTU/year 
at a cost of approximately $49,000/year.
    We believe that the costs and other impacts of the beyond-the-floor 
option for back-end process operations for the Butyl Rubber Production 
subcategory are reasonable, given the level of emission reduction. 
Therefore, we are proposing Option 2 for the Butyl Rubber Production 
subcategory, the beyond-the-floor option. We are requesting comment on 
this analysis and these options.
    We believe that the costs and other impacts of the beyond-the-floor 
option for the Halobutyl Rubber Production subcategory back-end process 
operations are not reasonable, given the level of emission reduction. 
Therefore, we are proposing Option 1, the MACT floor option. We are 
requesting comment on this analysis and these options.
    As noted above, we have proposed and finalized a decision that the 
MACT standard for the Butyl Rubber Production source category, prior to 
the implementation of the proposed emission limitations to the front-
end process vent and back-end process operations discussed in this 
section, provides an ample margin of safety to protect public health. 
Since both subcategories of this source category were ``low risk'' 
prior to these proposed emission limitations, we maintain that after 
their implementation, which will only further reduce HAP emissions, the 
rule will continue to provide an ample margin of safety to protect 
public health. Consequently, we do not believe it will be necessary to 
conduct another residual risk review under CAA section 112(f) for this 
source category 8 years following promulgation of new front-end process 
vent and back-end process limitations, merely due to the addition of 
these new MACT requirements.

C. What are the results and proposed decisions for the Marine Tank 
Vessel Loading Operations source category?

1. Overview of the Source Category and MACT Standards
    The NESHAP for MTVLO were promulgated on September 19, 1995 (60 FR 
48388), and codified at 40 CFR part 63, subpart Y. The MTVLO MACT-based 
standards apply to major sources and regulate HAP emissions from: Land-
based terminals, off-shore terminals, and the Alyeska Pipeline Service 
Company's Valdez Marine Terminal.

[[Page 65112]]

    MTVLO are conducted at terminals that load liquid commodities in 
bulk, such as crude oil, gasoline, and other fuels, and some chemicals 
and solvent mixtures. The cargo is pumped from the terminal's large, 
above-ground storage tanks through a network of pipes into a storage 
compartment (tank) on the vessel. Emissions occur as vapors are 
displaced from the tank as it is being filled. Most MTVLO facilities 
are either independent terminals or are associated with petroleum 
refineries or synthetic organic chemical manufacturers.
    For purposes of the MTVLO analysis, we considered only emissions 
from those sources that are part of the MTVLO source category. We 
recognize that there are additional sources of emissions at these 
facilities that are not part of the MTVLO source category. Those 
emission sources include emissions from hatch leaks or J tubes during 
transit, lightering operations, ballasting wastewater from non-
segregated ballasting, cleaning of the cargo tank (especially when 
changing products), and ventilating the cargo tank prior to loading. We 
are investigating these sources to understand their emissions and any 
controls used to reduce those emissions and request information about 
these sources that are currently not part of the MTVLO source category.
    The primary emission sources of displaced vapors associated with 
MTVLO activities include open tank hatches and overhead vent systems. 
Other possible emission points are hatch covers or domes, pressure or 
vacuum relief valves, seals, and vents. The MACT standards require 
control of all displaced vapors that result from product loading at 
affected sources irrespective of the point from which those vapors are 
emitted. Typical control devices used to reduce HAP emissions at 
affected facilities include vapor collection systems routed to either 
combustion or recovery devices, such as flares, incinerators, 
absorbers, carbon adsorbers, and condensers.
    When we developed the MTVLO MACT, we estimated that approximately 
300 major source facilities with MTVLO would be subject to the MACT 
standards. However, data in the 2005 NEI were only available for 152 
facilities subject to the MACT standards and the analyses discussed in 
this section are based on these 152 facilities. We believe the 152 
facilities emit HAP that are representative of HAP emissions within the 
source category because, based on available information, we expect that 
the rest of the facilities in the source category generally emit the 
same HAP as do the 152 modeled facilities. In addition, we expect that 
these 152 terminals represent the larger-emitting terminals, based on 
the specific terminals included in the 2005 NEI and the average 
reported emissions from these terminals (2.8 TPY of HAP on average).
    Marine terminals with MTVLO located at petroleum refineries are not 
part of the MTVLO source category, but are subject to the MTVLO MACT-
based standards because the Refinery NESHAP, 40 CFR part 63, subpart 
CC, incorporate those requirements by reference. However, marine 
terminals that are part of the Petroleum Refineries source category 
were not included in this risk assessment because they are not in the 
MTVLO source category. For these reasons, we are proposing to exclude 
refineries from the additional control requirements that are being 
proposed in this action. Loading operations at marine terminals that 
are part of the Petroleum Refineries source category will be addressed 
in a separate RTR rulemaking action.
2. What data were used in our risk analyses?
    We initially created a preliminary data set for the source category 
using data in the 2002 NEI Final Inventory, Version 1 (made publicly 
available on February 26, 2006), which we reviewed and changed where 
necessary to ensure that the proper facilities were included and that 
emissions from the proper processes were allocated to the MTVLO source 
category. We also reviewed the emissions and other data to identify 
data anomalies that could affect risk estimates. On March 29, 2007, we 
published an ANPRM (72 FR 29287) requesting comments on and updates to 
this data set, as well as the data sets for the other source categories 
included in the notice. Comments received in response to the ANPRM were 
reviewed and considered, and adjustments were made to the data set 
where we concluded the comments supported such adjustment. After making 
appropriate changes to the data set based on this public data review 
process, we created the data set on which we based the initial 
proposal. This data set was used to conduct the risk assessment and 
other analyses for the MTVLO source category that formed the basis for 
the actions included in the October 2008, proposal.
    Since the initial October 2008 proposal, we have continued to 
scrutinize the existing data set and have evaluated all additional data 
that became available subsequent to the proposal. Uncertainty about 
possible changes in the industry led us to extract more recent data 
from the NEI and, ultimately, to replace the entire 2002 NEI-based 
MTVLO data set with a data set based on the 2005 NEI. Additionally, we 
continue to work with industry representatives to resolve data issues 
found with facilities modeled with a MIR above 1-in-1 million 
(discussed in the next section) using the 2005 NEI data. The industry's 
review to date is provided in the docket for public review and comment.
    The 2005 NEI-based data set shows 420 TPY of total HAP emissions 
from the 152 modeled facilities in the data set. Hexane, methyl 
tertiary butyl ether, toluene, methanol, benzene, and xylenes account 
for the majority of the HAP emissions from loading operations included 
in the MTVLO source category at the 152 facilities in the data set 
(approximately 350 TPY, or 79 percent of the total HAP emissions by 
mass). These facilities also reported relatively small emissions of 56 
other HAP.
3. What are the results of the risk assessments and analyses?
    We have conducted a revised inhalation risk assessment for the 
MTVLO source category. We have also conducted an assessment of 
facility-wide risks and performed a demographic analysis of population 
risks. Table C.1 provides an overall summary of the results of the 
revised inhalation risk assessment.

[[Page 65113]]

                              Table C.1--Marine Tank Vessel Loading Operations Revised Inhalation Risk Assessment Results *
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                          Maximum individual                                 Maximum chronic non-
                                           cancer risk (in 1                     Annual        cancer TOSHI \3\
                                             million) \2\         Population     cancer   --------------------------
       Number of facilities \1\       --------------------------  at risk >=   incidence                              Maximum off-site acute non-cancer
                                          Actual     Allowable      1-in-1     (cases per     Actual     Allowable                  HQ \4\
                                        emissions    emissions     million       year)      emissions    emissions
                                          level        level                                  level        level
--------------------------------------------------------------------------------------------------------------------------------------------------------
152 Modeled Facilities...............           20           60       71,000         0.01          0.3          0.9  HQREL = 1 benzene
300 Major Source Facilities Subject             20           60      140,000         0.02          0.3          0.9  HQREL = 1 benzene
 to the MTVLO MACT Standard.
--------------------------------------------------------------------------------------------------------------------------------------------------------
* All results are for impacts out to 50 km from every source in the category.
\1\ There were 152 facilities in the data set that were modeled. We believe that these facilities are representative of the entire source category and
  that the maximum risks arising from any individual facility in the source category are properly characterized. The population risks were scaled up
  based on a linear relationship.
\2\ Maximum individual excess lifetime cancer risk.
\3\ Maximum TOSHI. The target organ with the highest TOSHI for the MTVLO source category is the reproductive 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 threshold. See section IV.A of this preamble for explanation of acute threshold values.

    The inhalation risk modeling was performed using actual emissions 
level data. As shown in Table C.1, the results of the revised 
inhalation risk assessment indicate the maximum lifetime individual 
cancer risk could be as high as 20-in-1 million, the maximum chronic 
non-cancer TOSHI value could be up to 0.3. The total estimated national 
cancer incidence from these facilities based on actual emission levels 
at the 152 modeled facilities is 0.01 excess cancer cases per year or 
one case in every 100 years. The total estimated cancer incidence for 
the MTVLO source category could, however, be as high as 0.02, or one 
case in every 50 years, considering that there may be 300 facilities in 
the source category. The maximum off-facility-site acute HQ value could 
be as high as 1, based on the actual emissions level and the REL value 
for benzene.
    In evaluating potential differences between actual emission levels 
and emissions allowable under the MACT-based standards, we investigated 
the specific controls in use at facilities associated with cancer risks 
greater than 1-in-1 million and determined that the highest factor for 
one of these facilities was 3.0, based on the ability of these 
facilities to achieve 98-percent control of emissions where only 97-
percent emissions control is required by the MACT standards for another 
facility, they could, under MACT, increase emissions by a factor of 3. 
Therefore, the maximum individual cancer risk based on MACT-allowable 
emissions is estimated to be up to 60-in-1 million, and the maximum 
chronic non-cancer TOSHI value is up to 0.9.
    Table C.2 displays the results of the facility-wide risk 
assessment. This assessment was conducted based on actual emission 
levels for the 152 modeled facilities.

   Table C.2--Marine Tank Vessel Loading Operations Facility-Wide Risk
                           Assessment Results
------------------------------------------------------------------------

------------------------------------------------------------------------
Maximum facility-wide individual cancer risk (in 1 million)..        200
    MTVLO source category contribution to this maximum               10%
     facility-wide individual cancer risk \1\................
Maximum facility-wide chronic non-cancer TOSHI...............          4
    MTVLO source category contribution to this maximum               20%
     facility-wide non-cancer TOSHI \1\......................
------------------------------------------------------------------------
\1\ Percentage shown reflects MTVLO source category contribution to the
  maximum facility-wide risks at the facility with the maximum risk
  value shown.

    The maximum individual cancer risk from all HAP emissions at a 
facility that contains sources subject to the MTVLO MACT standards is 
estimated to be 200-in-1 million, and the maximum chronic non-cancer 
TOSHI value is estimated to be 4. The highest facility-wide cancer risk 
for a facility that includes a MTVLO source is primarily driven by 
emissions associated with sources subject to the organic liquids 
distribution (OLD) NESHAP, 40 CFR part 63, subpart EEEE, and the 
highest facility-wide non-cancer risk is primarily driven by chemical 
manufacturing processes. The OLD and chemical manufacturing process 
emissions will be addressed as part of our effort to develop integrated 
requirements for the chemical manufacturing sector. We intend to 
develop integrated rules for the chemical manufacturing sector over the 
next 2 years.
    The results of the demographic analyses performed to investigate 
the distribution of risks above 1-in-1 million, based on actual 
emissions levels for the population living within 5 km of the 
facilities, among various demographic groups are provided in a report 
available in the docket for this action and summarized in Table C.3 
below.

[[Page 65114]]

                                   Table C.3--Marine Tank Vessel Loading Operations Demographic Risk Analysis Results
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                 Population with risk greater than 1-in-1 million
                                               Maximum   -----------------------------------------------------------------------------------------------
              Emissions basis                risk  (in 1                                       Other and   Hispanic                Below the  Over 25 W/
                                               million)      Total    Minority %    African     multi-    or  Latino    Native      poverty     O a HS
                                                          (millions)              American %   racial %        %      American %    level %    diploma %
--------------------------------------------------------------------------------------------------------------------------------------------------------
Nationwide.................................          n/a         285          25          12          12          14         0.9          13          13
Source Category............................           20        0.06          29           7          21          38         0.6          15          19
Facility-wide..............................          200         0.8          38          18          39          14         0.5          18          18
--------------------------------------------------------------------------------------------------------------------------------------------------------

    The results of the demographic analysis show that, for the MTVLO 
source category, of the 60,000 people with cancer risk greater than 1-
in-1 million, 29 percent could be classified as a ``Minority,'' 38 
percent are included in the ``Hispanic or Latino'' demographic group, 
21 percent are included in the ``Other and Multiracial'' demographic 
group, 15 percent are included in the ``Below Poverty Level'' 
demographic group, and 19 percent are included in the ``Over 25 Without 
a High School Diploma'' demographic group. The percentage of the 
population within 5 km of the terminal and with a cancer risk greater 
than 1-in-1 million is higher than the typical distribution of these 
demographic groups across the United States. The facility-wide 
demographic analysis shows that many more people (800,000) are at 
cancer risk greater than 1-in-1 million. As with the MTVLO analysis, 
many of the demographic groups have disparate impacts compared to the 
distribution across the United States.
    Details of these assessments and analyses can be found in the 
residual risk documentation referenced in section IV.A of this 
preamble, which is available in the docket for this action.
4. What are our proposed decisions on risk acceptability and ample 
margin of safety?
a. October 2008 Proposed Decision
    In October 2008, we proposed that the risks were acceptable because 
the risk results indicated that cancer risks to the individual most 
exposed to emissions from the category were greater than 1-in-1 
million, but less than 100-in-1 million, and there were no other 
significant health impacts. We identified one emissions control option 
that would reduce risks in the ample margin of safety determination. We 
proposed that such control was not necessary to protect public health 
with an ample margin of safety in light of the high costs and limited 
additional health protection it would provide. We also proposed that 
emissions from the source category posed no potential for adverse 
environmental effects, did not pose potential for human health 
multipathway risks, and were unlikely to cause acute or chronic non-
cancer health impacts. Therefore, we proposed that the existing 
standards provided an ample margin of safety and proposed to re-adopt 
the existing MACT standards to satisfy section 112(f) of the CAA.
b. Risk Acceptability
    The revised risk analysis we performed for this proposal indicates 
that the cancer risks to the individual most exposed is 20-in-1 million 
based on actual emissions and 30-in-1 million based on MACT-allowable 
emissions. The cancer incidence and the number of people exposed to 
cancer risks of 1-in-1 million or greater are relatively low, based on 
actual emissions. The analyses show no potential for adverse 
environmental effects or human health multipathway effects, and that 
chronic, non-cancer health impacts are unlikely. The revised assessment 
did indicate that an acute non-cancer HQ as high as 1 could occur, 
based on the REL value. Our additional analysis of facility-wide risks 
shows that the maximum facility-wide cancer risk is 200-in-1 millions 
and the maximum facility-wide non-cancer TOSHI is 4. It also shows that 
the MTVLO processes located at the facilities with these maximum risk 
values contribute approximately 10 and 20 percent to such risks, 
respectively. Our additional analyses of the demographics of the 
exposed population show disparities in risks between demographic 
groups, but MTVLO represent a small portion of the population at risk. 
Based on this low cancer risk level and in consideration of other 
health measures and factors, including the low cancer incidence (one 
case in every 100 years) and the low maximum non-cancer risk level 
(TOSHI of 0.3 based on actual emissions and 0.5 based on MACT-allowable 
emissions), we propose that the risks from the MTVLO source category 
are acceptable.
c. Ample Margin of Safety
    Because we are proposing that the risks are acceptable, but still 
above 1-in-1 million, we then reconsidered our 2008 ample margin of 
safety decision.
    We have not identified any additional control options or any 
changes to the previously-analyzed control option that would further 
reduce risks from MTVLO that have cancer risks above 1-in-1 million. 
Our analysis does not indicate a change in the emissions reductions 
that could be achieved or in the cost of control for the control option 
considered, but ultimately rejected, in the October 2008 proposal. 
Therefore, we continue to propose that the current MACT-based standards 
provide an ample margin of safety to protect public health and the 
environment, and we are proposing to re-adopt the existing MACT 
standards to satisfy section 112(f) of the CAA.
5. What are our proposed decisions on the technology review?
    In the October 10, 2008 proposal, as part of our technology review, 
we stated that we had not identified any advancements in practices, 
processes, and control technologies applicable to the emission sources 
in the MTVLO source category that would result in decreased emissions, 
and, on that basis, proposed to re-adopt the existing MACT standards to 
satisfy section 112(d)(6) of the CAA. In that review, we examined the 
regulatory requirements and/or technical analyses for subsequently-
promulgated air toxics regulations applicable to source categories with 
emission sources similar to those in the MTVLO source category, and we 
searched the RBLC for controls applicable to VOC- and HAP-emitting 
processes in the MTVLO source category that might further reduce HAP 
emissions. In addition to reviewing subsequent regulatory actions 
applicable to similar types of emissions, such as those from loading 
racks or transfer operations, we also conducted a review for other VOC 
and organic HAP-emitting processes that would have similar, technology-
transferable controls.
    We conducted a further review in conjunction with this proposed 
rulemaking. The existing MACT

[[Page 65115]]

standards require collection and control for MTVLO facilities that load 
at least 10 million barrels per year (bbl/yr) of gasoline. As part of 
our technology review, we identified vapor collection and processors 
(recovery), as a possible control for additional gasoline loading MTLVO 
facilities. Recovery technology is appropriate for controlling mixtures 
of compounds and gasoline is the highest-quantity commodity loaded, 
based on our review of the Waterborne Commerce Statistics Center (WCSC) 
database for the United States. The WCSC database contains detailed 
information on the types and quantities of commodities loaded and 
unloaded at United States ports, harbors, waterways, and canals.
    As part of our technology review, we evaluated gasoline loading 
thresholds of 0.5, 1.0, and 5 million bbl/yr gasoline loaded. 
Specifically, we found that MTVLO facilities loading 5 million bbl/yr 
have approximately 25 tons per year of HAP emissions. Facilities with 
this level of HAP emissions are subject to the control requirements 
under the existing rule. Therefore, loading in excess of 5 million bbl/
yr of gasoline is already required to be controlled under the current 
standard.
    We estimated the cost-effectiveness and overall impacts of the 
vapor collection and recovery options as shown in Table C.4. As 
discussed earlier, the 5 million bbl/yr threshold would not achieve any 
HAP or VOC reductions beyond those required under the current rule. For 
the 1 million bbl/yr threshold, we estimate an additional 190 TPY of 
HAP emissions and 2,600 TPY of VOC emission reduction can be achieved. 
The cost-effectiveness of these controls is $74,000 per ton of HAP 
emission reduction and $5,500 per ton of VOC emission reduction. While 
the HAP cost-effectiveness is higher than our historical values, the 
VOC cost-effectiveness is within the range of acceptability. For the 
0.5 million bbl/yr option, the additional costs of controls is 
disproportionate to the additional emission reduction. As such, we are 
proposing to reduce the threshold in the current rule from 10 million 
bbl/yr to 1 million bbl/yr.

            Table C.4--Cost-Effectiveness and Nationwide Impacts for Vapor Collection and Recovery Controls for Sources With Gasoline Loading
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                          Total                        Net
  Gasoline loading threshold (million   Capital cost   annualized     Recovery     annualized   HAP emission    HAP cost-    VOC emission    VOC cost-
                bbl/yr)                  (million $)      cost         credit         cost        reduction   effectiveness    reduction   effectiveness
                                                       (million $)   (million $)   (million $)      (TPY)        ($/ton)         (TPY)        ($/ton)
--------------------------------------------------------------------------------------------------------------------------------------------------------
5.....................................             0             0             0             0             0  .............             0  .............
1.....................................            22            16             1            14           190         74,000         2,600          5,500
0.5...................................            36            22             2            20           240         85,000         3,200          6,300
--------------------------------------------------------------------------------------------------------------------------------------------------------

    The current rule requires a 97 percent HAP reduction for those 
facilities with a loading of 10 million bbl/yr. To foster the use of 
vapor recovery rather than combustion of the vapors, we considered 
additional formats for the standard. We looked to similar MACT 
standards for gasoline loading of tank trucks and rail cars. Based on 
our review of these standards, we believe that vapor recovery is 
capable of achieving an emission limit of less than or equal to 10 
milligrams of total organic compound emissions per liter of gasoline 
loaded (mg/l). The 10 mg/l emission limit also approximates the 97-
percent control that is required for the larger-emitting, existing 
MTVLO subcategories. Thus, we propose to provide facilities the option 
of either meeting the 97-percent control requirement or the equivalent 
emission limit of 10 mg/l.
    In summary, as a result of the technology review under section 
112(d)(6) of the CAA, we are proposing to lower the existing threshold 
for control of emissions from gasoline loading from 10 million bbl/yr 
to 1 million bbl/yr and to provide facilities the option of either 
meeting the 97-percent control requirement or the equivalent emission 
limit of 10 mg/l.
6. What other actions are we proposing?
a. SSM Provisions
    We reviewed the SSM provisions of the MTVLO NESHAP. The MTVLO 
NESHAP do contain an SSM exemption because they specify in 40 CFR 
63.560, Table 1 that 40 CFR 63.6(f)(1) applies. Consistent with Sierra 
Club v. EPA, EPA is proposing that standards in this rule would apply 
at all times. We determined that there are currently several cross-
references in the MTVLO NESHAP that could cause some confusion 
regarding periods of SSM. We also determined that the NESHAP do not 
specifically address recordkeeping and reporting requirements during 
periods of malfunction. We are, therefore, proposing several revisions 
to 40 CFR part 63, subpart Y to address these issues. We are also 
proposing to add language to 40 CFR 63.563(b)(1) to clarify the 
conditions during which performance tests shall be conducted. We are 
further proposing to revise 40 CFR 63.560, Table 1 to specify that the 
SSM included provisions in 40 CFR 63.6(f)(1), 40 CFR 63.7(e)(1), and 40 
CFR 63.10(c)(10)-(11) of the General Provisions do not apply. Finally, 
we are proposing to promulgate an affirmative defense against civil 
penalties for exceedances of emission standards caused by malfunctions, 
as well as criteria for establishing the affirmative defense.
    EPA has attempted to ensure that we have removed any provisions in 
the regulatory text that are inappropriate, unnecessary, or redundant 
in the absence of the SSM exemption. We are specifically seeking 
comment on whether there are any such provisions that we have 
inadvertently overlooked.
b. Significant Emission Points Not Previously Regulated
    We also conducted a review of the MTVLO NESHAP to determine whether 
there were significant emissions sources for which standards were not 
previously developed. In this review, we identified two subcategories, 
those facilities emitting less than 10/25 TPY of HAP, and those 
facilities located more than 0.5 miles from shore, for which the 
current NESHAP do not include emission standards. As discussed below, 
we considered two levels of control (submerged fill and vapor recovery) 
for these two subcategories.
    Submerged fill reduces the amount of emissions generated from the 
loading of vessels by reducing turbulence and misting. Use of this 
technique results in a 60-percent reduction in emissions compared to 
splash loading. We have determined that submerged fill is currently 
used by most, if not all, of the facilities. We reached this conclusion

[[Page 65116]]

based on information obtained through contact with industry 
representatives and the Coast Guard about submerged filling. Existing 
Coast Guard rules (46 CFR 153.282) require that ``the discharge point 
of a cargo tank filling line must be not higher above the bottom of the 
cargo tank or sump than 10 centimeters (approximately 4 inches) or the 
radius of the filling line, whichever is greater.'' According to Coast 
Guard representatives, the radius of the fill lines can be up to 6 
inches. We are proposing that the submerged fill technique is the MACT 
floor.
    We next undertook an evaluation of potential beyond-the-floor 
options for the two identified subcategories. The only option beyond 
the floor is the application of vapor collection and processors, which 
were the basis for the emissions standards applicable to other MTVLO, 
at existing facilities in two subcategories of the MTVLO NESHAP (60 FR 
48388). We examined the use of these controls by sources in the two 
subcategories in the context of the original MACT standards, but 
rejected their use as a beyond the floor option because they were not 
cost effective. As described above under the technology review, we are 
proposing to lower the threshold for using vapor collection and 
processing at MTVLO facilities loading gasoline from 10 million bbl/yr 
to 1 million bbl/yr. We are also proposing to provide facilities the 
option of either meeting the 97-percent control requirement or the 
equivalent emission limit of 10 mg/l. For the reasons set forth above, 
we are proposing these same requirements as a beyond the floor measure 
for these two subcategories. As for those facilities that do not load 1 
million bbl/yr, we are proposing no additional controls as part of our 
beyond the floor analysis.
    In conclusion, we are proposing in this action to set submerged 
fill as the floor level of control for these two MTVLO subcategories. 
Additionally, we are proposing vapor recovery as a beyond-the-floor 
option for those two MTVLO subcategories if they load 1 million bbl/yr 
or more of gasoline.
    As noted above, we are proposing that the MACT standards, prior to 
the implementation of the proposed emission limitations discussed in 
this section, provide an ample margin of safety to protect public 
health. Therefore, we maintain that after implementation, which will 
further reduce HAP emissions, the rule will continue to provide an 
ample margin of safety to protect public health. Consequently, we do 
not believe it will be necessary to conduct another residual risk 
review under CAA section 112(f) for this source category 8 years 
following promulgation of these limitations.

D. What are the results and proposed decisions for the Pharmaceuticals 
Production source category?

1. Overview of the Source Category and MACT Standard
    The National Emission Standards for Pharmaceuticals Production were 
promulgated on September 21, 1998 (63 FR 50280) and codified at 40 CFR 
part 63, subpart GGG. The Pharmaceuticals Production MACT standards 
apply to major sources of HAP. We identified 27 facilities currently 
subject to the Pharmaceuticals Production MACT standards.
    The pharmaceutical manufacturing process consists of chemical 
production operations that produce drugs and medication. These 
operations include chemical synthesis (deriving a drug's active 
ingredient) and chemical formulation (producing a drug in its final 
form).
    Emission sources at pharmaceutical production facilities include 
breathing and withdrawal losses from chemical storage tanks, venting of 
process vessels, leaks from piping and equipment used to transfer HAP 
compounds (equipment leaks), and volatilization of HAP from wastewater 
streams.
    Typical control devices used to reduce HAP emissions from process 
vents include flares, incinerators, scrubbers, carbon adsorbers, and 
condensers. Emissions from storage vessels are controlled by floating 
roofs or by routing them to a control device. Emissions from wastewater 
are controlled by a variety of methods, including equipment 
modifications (e.g., fixed roofs on storage vessels and oil water 
separators; covers on surface impoundments containers, and drain 
systems), treatment to remove the HAP (steam stripping, biological 
treatment), control devices, and work practices. Emissions from 
equipment leaks typically are reduced by leak detection and repair work 
practice programs, and in some cases, by equipment modifications.
2. What data were used in our risk analyses?
    We initially created a preliminary data set for the source category 
using data in the 2002 NEI Final Inventory, Version 1 (made publicly 
available on February 26, 2006). We reviewed the NEI data set and made 
changes where necessary to ensure the proper facilities were included 
and to ensure the proper processes were allocated to the 
Pharmaceuticals Production source category. We also reviewed the 
emissions and other data to identify data anomalies that could affect 
risk estimates. On March 29, 2007, we published an ANPRM (72 FR 29287) 
for the express purpose of requesting comments and updates to this data 
set, as well as to the data sets for the other source categories 
addressed in that ANPRM. Comments received in response to the ANPRM 
were reviewed and considered, and we made adjustments to the data set 
where we concluded the comments supported such adjustment. After making 
appropriate changes to the data set based on this public data review 
process, the data set on which we based the initial proposal was 
created. This data set was used to conduct the risk assessment and 
other analyses for the Pharmaceuticals Production source category that 
formed the basis for the proposed RTR review actions included in the 
October 10, 2008 proposal.
    We have continued to scrutinize the existing data set and have 
evaluated any additional data that has become available since the 
October 10, 2008 proposal. Since the time of the proposal, we 
identified an error in the latitude/longitude coordinates of one 
emission point at one facility. This error has been corrected in the 
data set, and no other changes have been made to it since the proposal.
    Methylene chloride, methanol, acetonitrile, and toluene account for 
the majority of the HAP emissions from these facilities (approximately 
890 TPY, or 85 percent of the total HAP emissions by mass). These 
facilities also reported relatively small emissions of 54 other HAP. 
For more detail, see the memo in the docket for this action describing 
the risk assessment inputs and models for the Pharmaceuticals 
Production source category.
    We estimate that MACT-allowable emissions from this source category 
could be up to 25 percent greater than the actual emissions, primarily 
from process vents, as it is possible that the control devices used at 
some facilities achieve greater emission reductions from these emission 
sources than what is required by the MACT standard. For more detail 
about this estimate of the ratio of actual to MACT-allowable emissions, 
see the memo in the docket for this action describing the estimation of 
MACT-allowable emission levels and associated risks and impacts.
3. What are the results of the risk assessments and analyses?
    We have conducted a revised inhalation risk assessment for the

[[Page 65117]]

Pharmaceuticals Production source category. We have also conducted an 
assessment of facility-wide risk and performed a demographic analysis 
of population risks. Table D.1 provides an overall summary of the 
results of the revised inhalation risk assessment.

                                   Table D.1--Pharmaceuticals Production Revised Inhalation Risk Assessment Results *
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                            Maximum individual                                 Maximum chronic non-
                                             cancer risk (in 1                     Annual        cancer TOSHI \3\
                                               million) \2\         Population     cancer   --------------------------
       Number of  facilities \1\        --------------------------  at risk >=   incidence                             Maximum off-site acute non-cancer
                                            Actual     Allowable      1-in-1     (cases per     Actual     Allowable                 HQ \4\
                                          emissions    emissions     million       year)      emissions    emissions
                                            level        level                                  level        level
--------------------------------------------------------------------------------------------------------------------------------------------------------
27.....................................            3            4        2,000       0.0008          0.2          0.4  HQREL = 2 glycol ethers,
                                                                                                                        chloroform
                                                                                                                       HQAEGL	1 = 0.001 chloroform
--------------------------------------------------------------------------------------------------------------------------------------------------------
* All results are for impacts out to 50 km from every source in the category.
\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 Pharmaceutical Production source category is the nervous 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 threshold. See section IV.A of this preamble for explanation of acute threshold values.

    The inhalation risk modeling was performed using actual emissions 
level data. As shown in Table D.1, the results of the revised 
inhalation risk assessment indicate the maximum lifetime individual 
cancer risk could be as high as 3-in-1 million, the maximum chronic 
non-cancer TOSHI value could be up to 0.2. The total estimated national 
cancer incidence from these facilities based on actual emission levels 
is 0.0008 excess cancer cases per year, or one case in every 1,250 
years. The maximum off-facility-site acute HQ value could be as high as 
2, based on the actual emissions level and the REL value for 
chloroform. The HQ value at this level occurs at a location adjacent to 
one facility fenceline for only a few (13) hours per year. This maximum 
exceedance of the REL value corresponds to an HQAEGL-2 equal 
to 0.001. We also note a possible exceedance of the short-term REL 
value for glycol ethers at one other facility (HQREL = 2). 
There are no other appropriate acute threshold values available for 
glycol ethers on which to base a comparison of potential risk.
    Our analysis of potential differences between actual emission 
levels and emissions allowable under the MACT standards indicated that 
MACT-allowable emission levels may be up to 25 percent greater than 
actual emission levels. Considering this difference, the risk results 
from the revised inhalation risk assessment indicate the maximum 
lifetime individual cancer risk could be as high as 4-in-1 million, and 
the maximum chronic non-cancer TOSHI value could be up to 0.4 at the 
MACT-allowable emissions level.
    Table D.2 displays the results of the facility-wide risk 
assessment. This assessment was conducted based on actual emission 
levels.

   Table D.2--Pharmaceuticals Production Facility-Wide Risk Assessment
                                 Results
------------------------------------------------------------------------

------------------------------------------------------------------------
Maximum facility-wide individual cancer risk (in 1 million)..         40
    Pharmaceuticals Production source category contribution          <1%
     to this maximum facility-wide individual cancer risk \1\
Maximum facility-wide chronic non-cancer TOSHI...............        0.8
    Pharmaceuticals Production source category contribution          <1%
     to this maximum facility-wide chronic non-cancer TOSHI
     \1\.....................................................
------------------------------------------------------------------------
\1\ Percentage shown reflects Pharmaceuticals Production source category
  contribution to the maximum facility-wide risks at the facility with
  the maximum risk value shown.

    The maximum individual cancer risk from all HAP emissions at a 
facility that contains sources subject to the Pharmaceuticals 
Production MACT standards is estimated to be 40-in-1 million, and the 
maximum chronic non-cancer TOSHI value is estimated to be 0.8. At the 
facility where these maximum risk values occur, the estimated 
proportion of the risk attributable to the Pharmaceuticals Production 
source category processes is less than one percent for both cancer and 
non-cancer risk. The highest facility-wide cancer risk for a facility 
that includes a pharmaceuticals production source is primarily driven 
by acrylonitrile-butadiene-styrene (ABS) resin production processes, 
and the highest facility-wide non-cancer risk is primarily driven by 
pesticide manufacturing processes. These ABS resin and pesticide 
manufacturing processes will be addressed in future residual risk and 
technology reviews.
    The results of the demographic analyses performed to investigate 
the distribution of risks above 1-in-1 million, based on actual 
emissions levels for the population living within 5 km of the 
facilities, among various demographic groups are provided in a report 
available in the docket for this action and summarized in Table D.3 
below.

[[Page 65118]]

                                         Table D.3--Pharmaceuticals Production Demographic Risk Analysis Results
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                 Population with risk greater than 1-in-1 million
                                              Maximum   ------------------------------------------------------------------------------------------------
              Emissions basis               risk  (in 1                                       Other and    Hispanic                Below the  Over 25 W/
                                              million)      Total    Minority %    African   multiracial   or Latino    Native      poverty     O a HS
                                                         (millions)              American %       %            %      American %    level %    diploma %
--------------------------------------------------------------------------------------------------------------------------------------------------------
Nationwide................................          n/a         285          25          12           12          14         0.9          13          13
Source category...........................            3       0.002          12           4            8          34         0.5          32          25
Facility-wide.............................           40        0.03          18          14            4          12         0.3          21          15
--------------------------------------------------------------------------------------------------------------------------------------------------------

    The results of the demographic analysis show that, for the 
Pharmaceuticals Production source category, of the population of 2,000 
people with cancer risk greater than 1-in-1 million, 34 percent are 
included in the ``Hispanic or Latino'' demographic group, 32 percent 
are included in the ``Below Poverty Level'' demographic group, and 25 
percent are included in the ``Over 25 Without a High School Diploma'' 
demographic group. The percentage of the population within 5 km of a 
pharmaceuticals production facility and with a cancer risk greater than 
1-in-1 million is higher than seen for these demographic categories 
based on the distribution of these demographic groups across the United 
States. The table also shows that the results of the facility-wide 
demographic analysis are higher than seen across the U.S, for the those 
included in the ``African American,'' ``Below Poverty Level,'' and the 
``Over 25 Without a High School Diploma'' demographic groups, but the 
risks are lower than these levels for the other demographic groups.
    Details of these assessments and analyses can be found in the 
residual risk documentation referenced in section IV.A of this 
preamble, which is available in the docket for this action.
4. What are our proposed decisions on risk acceptability and ample 
margin of safety?
a. October 2008 Proposed Decision
    In our October 10, 2008 proposal, we stated that the risks were 
acceptable because the risk results indicated that cancer risks to the 
individual most exposed to emissions from the category of 10-in-1 
million were greater than 1-in-1 million but less than 100-in-1 
million. We then analyzed other risk factors and emissions control 
options in the ample margin of safety determination. In this analysis, 
we found emissions from the source category posed no potential for an 
adverse environmental effect, did not pose potential for human health 
multi-pathway risks, and were unlikely to cause acute or chronic non-
cancer health impacts. We also identified one emissions control option 
that would reduce risks. We proposed that such control was not 
necessary to protect public health with an ample margin of safety in 
light of the high cost and limited additional health protection it 
would provide. Therefore, we proposed that the existing standard 
provided an ample margin of safety, and we proposed to re-adopt the 
existing MACT standard to satisfy section 112(f) of the CAA.
b. Risk Acceptability
    The revised inhalation risk analysis we performed for this proposal 
indicates that the cancer risks to the individual most exposed is 3-in-
1 million based on actual emissions and up to 4-in-1 million based on 
MACT-allowable emissions. The cancer incidence and the number of people 
exposed to cancer risks of 1-in-1 million or greater are not 
significantly changed from the risk identified in the October 2008 
proposal. Similarly, the risk analysis continued to show no potential 
for an adverse environmental effect or human health multi-pathway 
effects, and that chronic non-cancer health impacts are unlikely. The 
revised assessment did indicate that an acute non-cancer HQ as high as 
2 could occur, based on the REL value at a location adjacent to the 
facility fenceline for only a few (13) hours per year. However, we do 
not believe this situation warrants additional control considering the 
overall health effects. While our additional analysis of facility-wide 
risks showed that the maximum facility-wide cancer risk is 40-in-1 
million, it also showed that pharmaceutical sources located at such 
facilities contributed less than 1 percent to such risk. The facility-
wide analysis indicates that the maximum chronic non-cancer risks are 
unlikely to cause health impacts. Our additional analysis of the 
demographics of the exposed population may show disparities in risks 
between demographic groups. Based on this low cancer risk level and in 
consideration of other health measures and factors, including the low 
cancer incidence (one case in every 1,250 years) and the low maximum 
non-cancer risk level (TOSHI of 0.2 based on actual emissions and 0.4 
based on MACT-allowable emissions), we propose that the risks from the 
Pharmaceuticals Production source category are acceptable.
c. Ample Margin of Safety
    Because we are proposing that the risks are acceptable, but still 
above 1-in-1 million, we then re-considered our 2008 ample margin of 
safety decision.
    We have not identified any additional control options or any 
changes to the previously-analyzed control option that would affect 
emissions reductions or the costs of control. Therefore, we continue to 
propose that the current MACT standards provide an ample margin of 
safety to protect public health and the environment, and we are 
proposing to re-adopt the existing MACT standards to satisfy section 
112(f) of the CAA.
5. What are our proposed decisions on the technology review?
    In the October 10, 2008 proposal, we identified no developments in 
practices, processes, and control technologies applicable to the 
emission sources and thus we did not propose any additional controls as 
necessary under CAA section 112(d)(6). In that review, we examined the 
regulatory requirements and/or technical analyses for subsequently 
promulgated air toxics regulations with similar types of emissions 
sources as those in the Pharmaceuticals Production source category, and 
we conducted a search of the RBLC for controls for VOC- and HAP-
emitting processes in the Pharmaceuticals Production source category. 
We have not identified any additional developments in practices, 
processes, and control technologies since the proposal date. Thus, we 
are again proposing that it is not necessary to revise the existing 
MACT standards pursuant to section 112(d)(6).
6. What other actions are we proposing?
a. SSM Provisions
    We propose to eliminate the SSM exemption in the Pharmaceuticals

[[Page 65119]]

Production MACT standards. Consistent with Sierra Club v. EPA, EPA 
proposes that standards in this rule would apply at all times. We are 
proposing several revisions to 40 CFR part 63, subpart GGG. 
Specifically, we are proposing to revise Table 1 to indicate that the 
requirements in 40 CFR 63.6(e) of the General Provisions do not apply. 
The 40 CFR 63.6(e) requires owner or operators to act according to the 
general duty to ``operate and maintain any affected source, including 
associated air pollution control equipment and monitoring equipment, in 
a manner consistent with safety and good air pollution control 
practices for minimizing emissions.'' We are separately proposing to 
incorporate this general duty to minimize into 40 CFR 63.1250(g)(3). 
The 40 CFR 63.6(e) also requires the owner or operator of an affected 
source to develop a written SSM plan. We are proposing to remove the 
SSM plan requirement. We are proposing to remove the exemption 
provisions for periods of SSM in 40 CFR 63.1250(g), require that delay 
of equipment leak repair plans be contained in a separate document in 
40 CFR 63.1255(g)(4), revise 40 CFR 63.1257(a) to specify the 
conditions for performance tests, and revise the SSM associated 
monitoring, recordkeeping, and reporting requirements in 40 CFR 
63.1258(b)(8), 40 CFR 63.1259(a), and 40 CFR 63.1260(i) to require 
reporting and recordkeeping for periods of malfunction. We are also 
proposing to revise Table 1 to specify that 40 CFR 63.6(f)(1), 40 CFR 
63.7(e)(1), the last sentence of 40 CFR 63.8(d)(3), 40 CFR 
63.10(c)(10), (11), and (15), and 40 CFR 63.10(d)(5) of the General 
Provisions do not apply. In addition, we are proposing to promulgate an 
affirmative defense against civil penalties for exceedances of emission 
standards caused by malfunctions, as well as criteria for establishing 
the affirmative defense. EPA has attempted to ensure that we have not 
incorporated into proposed regulatory language any provisions that are 
inappropriate, unnecessary, or redundant in the absence of the SSM 
exemption. We are specifically seeking comment on whether there are any 
such provisions that we have inadvertently incorporated or overlooked.
b. Rule Improvements Review
    We are proposing to correct an editorial error in 40 CFR 
63.1257(e)(2)(iii)(A)(6)(ii). That section specifies several criteria 
under which the inlet to the equalization tank may be considered as the 
inlet to the biological treatment process for the purposes of 
performance tests to show compliance with the standards in 40 CFR 
63.1256(a)(2)(i). This section incorrectly provides that only one of 
the listed criteria must be met for the inlet to the equalization tank 
to be considered the inlet to the biological treatment process. 
Instead, it should specify that all of the criteria must be met. Thus, 
we are proposing to revise this section by changing the ``or'' before 
each clause to ``and,'' to clarify that all the criteria of 40 CFR 
63.1256(e)(2)(iii)(A)(6)(ii) must be met for the inlet to the 
equalization tank to be considered as the inlet to the biological 
treatment process.

E. What are the results and proposed decisions for the Printing and 
Publishing Industry source category?

1. Overview of the Source Category and MACT Standard
    The National Emission Standards for the Printing and Publishing 
Industry were promulgated on May 30, 1996 (61 FR 27132) and codified at 
40 CFR part 63, subpart KK. The Printing and Publishing Industry MACT 
standards apply to major sources of HAP. We identified 172 facilities 
currently subject to the Printing and Publishing Industry MACT 
standards.
    Printing and publishing facilities are those facilities that use 
rotogravure, flexography, and other methods, such as lithography, 
letterpress, and screen printing, to print on a variety of substrates, 
including paper, plastic film, metal foil, and vinyl. The Printing and 
Publishing Industry MACT standards include two subcategories: (1) 
Publication rotogravure printing and (2) product and packaging 
rotogravure and wide-web flexographic printing. Emissions at printing 
and publishing facilities result from the evaporation of solvents in 
the inks and from cleaning solvents. The emission points include 
printing presses and associated dryers and ink and solvent storage. 
Control techniques include recovery devices, combustion devices, and 
the use of non-HAP/low-HAP inks and cleaning solvents.
2. What data were used in our risk analyses?
    We initially created a preliminary data set for the source category 
using data in the 2002 NEI Final Inventory, Version 1 (made publicly 
available on February 26, 2006). We reviewed the NEI data and made 
changes where necessary to ensure the proper facilities were included 
and to ensure the proper processes were allocated to the Printing and 
Publishing Industry source category. We also reviewed the emissions and 
other data to identify data anomalies that could affect risk estimates. 
On March 29, 2007, we published an ANPRM (72 FR 29287) for the express 
purpose of requesting comments on and updates to this data set, as well 
as to the data sets for the other source categories addressed in that 
ANPRM. Comments received in response to the ANPRM were reviewed and 
considered, and we made adjustments to the data set where we concluded 
the comments supported such adjustment. After making appropriate 
changes to the data set based on this public data review process, the 
data set on which we based the initial proposal was created. This data 
set was used to conduct the risk assessment and other analyses for the 
Printing and Publishing Industry source category that formed the basis 
for the proposed RTR actions included in the October 2008 proposal.
    We have continued to scrutinize the existing data set and have 
evaluated any additional data that became available since the October 
2008 proposal. Since the time of the proposal, we identified errors in 
some HAP that were reported to be emitted and several facilities that 
were included have permanently closed. The data set was updated to 
correct the errors and remove the facilities that have closed.
    Toluene accounts for the majority of the HAP emissions from these 
facilities (approximately 7,105 TPY, or 83 percent of the total HAP 
emissions by mass). These facilities also reported relatively small 
emissions of 58 other HAP. These emissions are primarily from the 
evaporation of HAP present in the inks and other materials applied with 
rotogravure and flexographic processes.
    We estimate that MACT-allowable emissions from emission points 
within this source category could be up to five times greater than the 
actual emissions because some capture systems and control devices used 
on printers at some facilities could achieve greater emission 
reductions (in the range of 98 to possibly 100 percent) than what is 
required by the MACT standard (92 percent). For more detail about this 
estimate of the ratio of actual to MACT-allowable emissions, see the 
memo in the docket for this action describing the estimation of MACT-
allowable emission levels and associated risks and impacts.
3. What are the results of the risk assessments and analyses?
    We have conducted a revised inhalation risk assessment for the 
Printing and Publishing Industry source category. We have also 
conducted an assessment of facility-wide risk, and performed a 
demographic analysis of

[[Page 65120]]

population risks. Table E.1 provides an overall summary of the results 
of the revised inhalation risk assessment.

                                Table E.1--Printing and Publishing Industry Revised Inhalation Risk Assessment Results *
--------------------------------------------------------------------------------------------------------------------------------------------------------
                         Maximum individual cancer                                 Maximum chronic  non-
                          risk (in 1 million) \2\                    Annual          cancer TOSHI \3\
 Number of facilities  ----------------------------  Population      cancer    ----------------------------
          \1\              Actual       Allowable   at risk >= 1-   incidence      Actual       Allowable     Maximum off-site acute non-cancer HQ \4\
                          emissions     emissions   in-1 million   (cases per     emissions     emissions
                            level         level                       year)         level         level
--------------------------------------------------------------------------------------------------------------------------------------------------------
172...................            4            20           300        0.0006          0.08           0.4   HQREL = 10 toluene
                                                                                                            HQAEGL-1 = 0.6 toluene
--------------------------------------------------------------------------------------------------------------------------------------------------------
* All results are for impacts out to 50 km from every source in the category.
\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 Printing and Publishing Industry source category is the reproductive 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 threshold. See section IV.A. of this preamble for explanation of acute threshold values.

    The inhalation risk modeling was performed using actual emissions 
level data. As shown in Table E.1, the risks based on these actual 
emission levels indicate the maximum lifetime individual cancer risk 
could be as high as 4-in-1 million, the maximum chronic non-cancer 
TOSHI value could be up to 0.08. The total estimated national cancer 
incidence from these facilities based on the actual emission levels is 
0.0006 excess cancer cases per year, or one case in every 1,666 years. 
The maximum off-facility-site acute HQ value could be as high as 10, 
based on the actual emissions level and the REL value for toluene. The 
HQ value at this level occurs at a location adjacent to one facility 
fenceline for only a few (90) hours per year. This maximum exceedance 
of the REL value corresponds to an HQAEGL-1 equal to 0.6.
    Our analysis of potential differences between actual emission 
levels and emissions allowable under the MACT standard indicated that 
MACT-allowable emission levels may be up to five times greater than 
actual emission levels. Assuming this worst case difference occurred at 
the highest risk facility, the scaled risk results from the revised 
inhalation risk assessment would indicate the maximum lifetime 
individual cancer risk could be as high as 20-in-1 million, and the 
maximum chronic non-cancer TOSHI value could be up to 0.4.
    Table E.2 displays the results of the facility-wide risk 
assessment. This assessment was conducted based on actual emission 
levels.

     Table E.2--Printing and Publishing Industry Facility-Wide Risk
                           Assessment Results
------------------------------------------------------------------------

------------------------------------------------------------------------
Maximum facility-wide individual cancer risk (in 1 million)..         20
    Printing and Publishing Industry source category                < 1%
     contribution to this maximum facility-wide individual
     cancer risk \1\.........................................
Maximum facility-wide chronic non-cancer TOSHI...............     \1\ 20
    Printing and Publishing Industry source category            \3\ < 1%
     contribution to this maximum facility-wide chronic non-
     cancer TOSHI \2\........................................
------------------------------------------------------------------------
\1\ After risk modeling was complete, EPA received data that identified
  an error in emissions that caused this highest TOSHI value. After
  revising the emissions value, the highest facility-wide TOSHI is 2
  from a different facility.
\2\ Percentage shown reflects Printing and Publishing Industry source
  category contribution to the maximum facility-wide risks at the
  facility with the maximum risk value shown.
\3\ This percentage reflects the Printing and Publishing Industry source
  category contribution to the highest facility-wide TOSHI of 2, as
  noted in footnote 1 to this table.

The maximum individual cancer risk from all HAP emissions at a facility 
that contains sources subject to the Printing and Publishing Industry 
MACT standards is estimated to be 20-in-1 million, and the maximum 
chronic non-cancer TOSHI value is estimated to be 20. At the facilities 
where these maximum risk values occur, the estimated proportion of the 
risk attributable to the Printing and Publishing Industry source 
category processes is less than one percent for both cancer and non-
cancer risk.
    The results of the demographic analyses performed to investigate 
the distribution of risks above 1-in-1 million, based on actual 
emissions levels for the population living within 5 km of the 
facilities, among various demographic groups are provided in a report 
available in the docket for this action and summarized in Table E.3 
below.

                                      Table E.3--Printing and Publishing Industry Demographic Risk Analysis Results
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                 Population with risk greater than 1-in-1 million
                                              Maximum   ------------------------------------------------------------------------------------------------
              Emissions basis               risk  (in 1                                       Other and    Hispanic                Below the  Over 25 W/
                                              million)      Total    Minority %    African   multiracial   or Latino    Native      poverty     O a HS
                                                         (millions)              American %       %            %      American %    level %    diploma %
--------------------------------------------------------------------------------------------------------------------------------------------------------
Nationwide................................          n/a         285          25          12           12          14         0.9          13          13
Source Category...........................            4     0.00005           0           0            0           0           0          11           5

[[Page 65121]]

Facility-wide.............................           20        0.05          14           8            5           5         0.3           9          11
--------------------------------------------------------------------------------------------------------------------------------------------------------

    The results of the Printing and Publishing Industry source category 
demographic analysis show that for the 50 people living within 5 km of 
a printing and publishing industry facility and with a cancer risk 
greater than 1-in-1 million is less than the national averages for the 
demographic categories displayed in Table E.3, based on the typical 
distribution of these demographic groups across the United States. The 
table also shows that the results of the demographic analysis for the 
facility-wide emissions are similarly less than the national averages 
for these demographic groups. This means the emissions from these 
sources do not create any significant disparate risk impacts.
    Details of these assessments and analyses can be found in the 
residual risk documentation as referenced in section IV.A of this 
preamble, which is available in the docket for this action.
4. What are our proposed decisions on risk acceptability and ample 
margin of safety?
a. October 2008 Proposed Decision
    In our October 10, 2008 proposal, the risk results indicated that 
cancer risk to the individual most exposed to emissions from the 
category was 0.05-in-1 million, which is less than 1-in-1 million 
(i.e., were ``low risk''). Therefore, we did not conduct an additional 
ample margin of safety analysis for the proposed rule.
b. Risk Acceptability
    While at the time of the October 10, 2008 proposal this source 
category showed low risks (cancer risks to the individual most exposed 
to emissions from the category were less than 1-in-1 million), in our 
revised analysis we found that cancer risks to the individual most 
exposed to emissions from the category were 4-in-1 million based on 
actual emissions and as high as 20-in-1 million based on MACT-allowable 
emissions. This change in risk is primarily the result of a cancer 
health benchmark value becoming available for ethyl benzene. The cancer 
incidence and the number of people exposed to cancer risks of 1-in-1 
million or greater are relatively low, based on actual emissions. The 
analyses show no potential for an adverse environmental effect or human 
health multi-pathway effects, and that chronic non-cancer health 
impacts are unlikely. The revised assessment did indicate that an acute 
non-cancer HQ as high as 10 could occur, based on the REL value for 
toluene at a location adjacent to the facility fenceline for up to 90 
hours per year. However, given the fact that this potential impact does 
not exceed the AEGL-1 value for toluene (HQAEGL-1 = 0.6) we 
do not believe this situation warrants additional control considering 
the overall health effects. Our additional analysis of facility-wide 
risks showed that the maximum facility-wide cancer risk is 20-in-1 
million and the maximum facility-wide non-cancer TOSHI is 20. It also 
showed that the printing and publishing processes located at the 
facilities with these maximum risk values contribute less than 1 
percent to such risks. As previously mentioned, our additional analysis 
of the demographics of the exposed population suggests there are not 
large disparities in risks between demographic groups.
    Based on this low cancer risk level and in consideration of other 
health measures and factors, including the low cancer incidence (one 
case in every 1,666 years), the low maximum non-cancer risk level 
(TOSHI of 0.08 based on actual emissions and 0.4 based on MACT-
allowable emissions), relatively low facility-wide risks which are not 
attributable to the printing and publishing category, and the lack of 
disparate impacts in the demographic analysis, we propose that the 
risks from the Printing and Publishing Industry source category are 
acceptable.
c. Ample Margin of Safety
    Because we are proposing that the risks are acceptable, but still 
above 1-in-1 million, we then re-considered our 2008 ample margin of 
safety decision. Based on these analyses, we continue to propose that 
the current MACT standards provide an ample margin of safety to protect 
public health and the environment, and we are proposing to re-adopt the 
existing MACT standards to satisfy section 112(f) of the CAA.
5. What are our proposed decisions on the technology review?
    In the October 2008 proposal, we identified no advancements in 
practices, processes, and control technologies applicable to the 
emission sources in the Printing and Publishing Industry source 
category in our technology review, and thus we proposed that it was not 
necessary to revise the existing MACT standards pursuant to section 
112(d)(6) of the CAA. In that review we examined the regulatory 
requirements and/or technical analyses for subsequently promulgated air 
toxics regulations with similar types of emissions sources as those in 
the Printing and Publishing Industry source category, and we conducted 
a search of the RBLC for controls for VOC- and HAP-emitting processes 
in the Printing and Publishing Industry source category. We re-examined 
these same sources of information to identify any new developments 
since the time of the October 2008 proposal. For the purposes of this 
proposal, we examined the option of retrofitting permanent total 
enclosures onto those controlled presses that do not already have 
permanent total enclosures. A permanent total enclosure improves the 
capture of solvent HAP from inks and delivers the additional captured 
solvent HAP to a control device. We estimate the cost-effectiveness of 
this retrofit to be over $50,000 per additional ton of HAP controlled. 
We find the cost of this retrofit to be disproportionate to the 
emission reduction that would be achieved. Thus, we are proposing that 
it is not necessary to revise the existing MACT standards pursuant to 
section 112(d)(6) of the CAA.
6. What other actions are we proposing?
    We propose to eliminate the SSM exemption in the Printing and 
Publishing Industry MACT standard. Consistent with Sierra Club v. EPA, 
EPA proposes that standards in this rule would apply at all times. We 
are proposing several revisions to 40 CFR part 63, subpart KK regarding 
the standards that apply during periods of

[[Page 65122]]

SSM. Specifically, we are proposing to revise Table 1 to indicate that 
the requirements of 40 CFR 63.6(e) of the General Provisions do not 
apply. Section 63.6(e) requires owners or operators to act according to 
the general duty to ``operate and maintain any affected source, 
including associated air pollution control equipment and monitoring 
equipment, in a manner consistent with safety and good air pollution 
control practices for minimizing emissions.'' We are separately 
proposing to incorporate this general duty to minimize emissions into 
40 CFR 63.823. The 40 CFR 63.6(e) also requires the owner or operator 
of an affected source to develop a written SSM plan. We are proposing 
to remove the SSM plan requirement. We are also proposing to revise 40 
CFR 63.827 to specify the conditions for performance tests and to 
revise 40 CFR 63.829 and 40 CFR 63.830 to require reporting and 
recordkeeping for periods of malfunction. We are proposing to revise 
Table 1 to specify that 40 CFR 63.6(f)(1), 40 CFR 63.7(e)(1), the last 
sentence of 40 CFR 63.8(d)(3), 40 CFR 63.10(b)(2)(i), (ii), (iv), and 
(v), 40 CFR 63.10(c)(10), (11), and (15), and 40 CFR 63.10(d)(5) of the 
General Provisions do not apply. In addition, we are proposing to 
promulgate an affirmative defense against civil penalties for 
exceedances of emission standards caused by malfunctions, as well as 
criteria for establishing the affirmative defense. EPA has attempted to 
ensure that we have not incorporated into proposed regulatory language 
any provisions that are inappropriate, unnecessary, or redundant in the 
absence of the SSM exemption. We are specifically seeking comment on 
whether there are any such provisions that we have inadvertently 
incorporated or overlooked.

F. What are the results and proposed decisions for Steel Pickling--HCl 
Process Facilities and Hydrochloric Acid Regeneration Plants source 
category?

1. Overview of the Source Category and MACT Standard
    The National Emission Standards for Steel Pickling--HCl Process 
Facilities and Hydrochloric Acid Regeneration Plants were promulgated 
on June 22, 1999 (64 FR 33202) and codified at 40 CFR part 63, subpart 
CCC. The Steel Pickling--HCl Process Facilities and Hydrochloric Acid 
Regeneration Plants MACT standards (i.e., Steel Pickling MACT standard) 
apply to major sources of HAP. We estimate that there are approximately 
80 facilities subject to the MACT standards that are currently 
performing steel pickling and/or acid regeneration. Many of these 
facilities are located adjacent to integrated iron and steel 
manufacturing plants or electric arc furnace steelmaking facilities 
(mini-mills) that produce steel from scrap. Facilities that regenerate 
HCl may or may not be located at steel pickling operations.
    The Steel Pickling source category consists of facilities that 
pickle steel, using HCl as the pickling acid, and facilities that 
regenerate the HCl after use, but does not include facilities which 
pickle steel using acids other than HCl.
    Steel pickling is a treatment process in which the heavy oxide 
crust or mill scale that develops on the steel surface during hot 
forming or heat treating is removed chemically in a bath of aqueous 
acid solution. Pickling is a process applied to metallic substances 
that removes surface impurities, stains, or crusts to prepare the metal 
for subsequent plating (e.g., with chromium) or other treatment, such 
as galvanization or painting.
    The HAP emission points from the steel pickling and acid 
regeneration processes include spray roasters, steel pickling baths, 
steel pickling sprays, and tank vents.
    Typical control devices used to reduce HAP emissions from steel 
pickling facilities include a packed tower scrubber, sieve tray 
scrubber, or horizontal packed bed scrubber. Each type of scrubber is 
coupled with a demister. The general trend in scrubber installations at 
steel pickling facilities is to replace older scrubbers with sieve tray 
scrubbers, which generate less scrubber effluent (blowdown). For acid 
regeneration roasters, a cyclone or a Venturi pre-concentrator is 
generally used before the emissions are scrubbed in one or two counter-
current packed tower absorbers.
2. What data were used in our risk analyses?
    For the Steel Pickling source category, we compiled preliminary 
data sets using data in the 2005 NEI. We reviewed these data and made 
changes where necessary. We also contacted several facilities to verify 
the emissions and emissions release characteristic data, and we made 
updates to the data set based on the information received from these 
communications. This updated data set comprises the data set that was 
used to conduct the risk assessments and other analyses that form the 
basis for this proposed action. Hydrochloric acid and chlorine account 
for all of the HAP emissions from the Steel Pickling source category 
(approximately 248 and 164 TPY, respectively).
    Our analysis of potential differences between actual emission 
levels and emissions allowable under the MACT standards indicate that 
actual emissions and allowable emissions are approximately the same as 
allowable emissions. The available data indicate that pickling 
processes throughout the industry are equipped with controls that 
achieve the HCl and chlorine emission limits required by the MACT 
standards. For more detail about this estimate of the ratio of actual 
to MACT-allowable emissions, see the memo in the docket for this action 
describing the estimation of MACT-allowable emission levels and 
associated risks and impacts.
3. What are the results of the risk assessments and analyses?
    We have conducted an inhalation risk assessment for the Steel 
Pickling source category. We have also conducted an assessment of 
facility-wide risk and performed a demographic analysis of population 
risks. Table F.1 provides an overall summary of the inhalation risk 
assessment results.

                         Table F.1--Steel Pickling Inhalation Risk Assessment Results *
----------------------------------------------------------------------------------------------------------------
                                    Maximum chronic non-cancer
                                             TOSHI \2\
                                 --------------------------------  Population at    Maximum off-site acute non-
    Number of facilities \1\          Actual         Allowable    risk from HI >           cancer HQ \3\
                                     emissions       emissions           1
                                       level           level
----------------------------------------------------------------------------------------------------------------
51 Modeled Facilities...........               2               2              30  HQREL = 0.4 chlorine

[[Page 65123]]

80 Major Source Facilities                     2               2              50  HQREL = 0.4 chlorine
 Subject to the MACT Standard.
----------------------------------------------------------------------------------------------------------------
* All results are for impacts out to 50 km from every source in the category.
\1\ There are 51 facilities in the data set that were modeled. It is believed that these facilities are
  representative of the entire source category and that the maximum risks are characterized. The population
  risks were scaled up based on a linear relationship.
\2\ Maximum TOSHI. The target organ with the highest TOSHI for the Steel Pickling source category is the
  neurological system.
\3\ 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
  threshold. See section IV.A of this preamble for explanation of acute threshold values.

    The results of the inhalation risk assessment indicated there are 
no cancer risks or incidences attributable to emissions from the Steel 
Pickling source category because there were no emissions of any HAP 
with cancer dose-response values (i.e., no known carcinogens are 
emitted from these sources). As shown in Table F.1, the maximum chronic 
non-cancer TOSHI value could be as high as 2. The maximum off-facility-
site acute HQ value could be as high as 0.4, based on the actual 
emissions level and the REL value for chlorine. As our analysis of 
potential differences between actual emission levels and emissions 
allowable under the MACT standards indicate, actual emissions are 
approximately the same as MACT-allowable emissions, and the risk 
results for actual emissions are approximately the same as those for 
MACT-allowable emissions.
    Table F.2 displays the results of the facility-wide risk 
assessment. This assessment was conducted based on actual emission 
levels for the 51 modeled facilities.

     Table F.2--Steel Pickling Facility-Wide Risk Assessment Results
------------------------------------------------------------------------

------------------------------------------------------------------------
Maximum Facility-Wide Individual Cancer Risk (in 1 million)..        100
    Steel Pickling source category contribution to this           \1\ NA
     maximum facility-wide individual cancer risk............
Maximum Facility-Wide Chronic Non-cancer TOSHI...............         10
    Steel Pickling source category contribution to this             < 1%
     maximum facility-wide chronic non-cancer TOSHI \2\......
------------------------------------------------------------------------
\1\ The Steel Pickling source category does not contribute to the
  facility-wide cancer risks, as the facilities in this source category
  do not report emissions of any HAP with cancer dose-response values.
\2\ Percentage shown reflects Steel Pickling source category
  contribution to the maximum facility-wide risks at the facility with
  the maximum risk value shown.

    The maximum individual cancer risk from all HAP emissions at a 
facility that contains sources subject to the Steel Pickling--HCl 
Process Facilities and Hydrochloric Acid Regeneration Plants MACT 
standards is estimated to be 100-in-1 million, and the maximum chronic 
non-cancer TOSHI value is estimated to be 10. As noted previously, 
there were no emissions of any HAP with cancer dose-response values 
from the Steel Pickling source category; therefore, this source 
category does not contribute to the maximum facility-wide cancer risk 
of 100-in-1 million. At the facility where the maximum TOSHI risk value 
occurs, the estimated proportion of the risk attributable to the Steel 
Pickling source category processes is less than one percent. The 
highest facility-wide cancer risk for a facility that includes a steel 
pickling or HCL regeneration source is primarily driven by iron and 
steel processes and coke oven emissions. The iron and steel processes 
will be addressed in a future residual risk review, some coke oven 
processes (charging, top side, and door leaks) have been addressed in a 
previous rulemaking action (70 FR 19992), and other coke oven processes 
(pushing, quenching, and battery stacks) will be addressed in a future 
residual risk review.
    The results of the demographic analyses performed to investigate 
the distribution of TOSHI greater than 1, based on actual emissions 
levels for the population living within 5 km of the facilities, among 
various demographic groups are provided in a report available in the 
docket for this action and summarized in Table F.3 below.

                                               Table F.3--Steel Pickling Demographic Risk Analysis Results
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                Population with TOSHI greater than 1-in-1 million
                                              Maximum   ------------------------------------------------------------------------------------------------
              Emissions basis               respiratory                                       Other and    Hispanic                Below the  Over 25  W/
                                               hazard       Total    Minority %    African   multiracial   or Latino    Native      poverty     O a HS
                                               index     (millions)              American %       %            %      American %    level %    diploma %
--------------------------------------------------------------------------------------------------------------------------------------------------------
Nationwide................................          n/a         175          32          16           15          16         0.6          13          13
Source Category...........................            2    0.000045           0           0            0           9           0           6           9
Facility-wide.............................           10      0.0017          41          34            6           1         0.2          11          13
--------------------------------------------------------------------------------------------------------------------------------------------------------

[[Page 65124]]

    The results of the Steel Pickling source category demographic 
analysis show that there are 45 people exposed to an HI of one or 
greater from the source category and 1,700 people exposed to an HI of 
one or greater for the facility-wide emissions. Of this relatively 
small number of people for the source category, none of the groups 
shows a disparate impact compared to the national distribution of non-
cancer risk. The facility-wide analysis shows a higher percentage 
population with an HI of one or more only for those that could be 
classified as a ``Minority'' and for those included in the ``African 
American'' demographic group.
    Details of these assessments and analyses can be found in the 
residual risk documentation as referenced in section IV.A of this 
preamble, which is available in the docket for this action.
4. What are our proposed decisions on risk acceptability and ample 
margin of safety?
a. Risk Acceptability
    The Steel Pickling source category does not emit HAP that are 
known, probable, or possible carcinogens; therefore, based on actual 
and MACT-allowable emission levels, cancer risks are less than 1-in-1 
million to the individual most exposed. The analyses we performed for 
this proposal show no potential for an adverse environmental effect or 
human health multi-pathway effects, and that acute non-cancer health 
impacts are unlikely. We determined that emissions from the Steel 
Pickling source category would result in chronic non-cancer TOSHI 
approximately equal to 2 for the individual most exposed based on 
either actual emissions or MACT-allowable emissions. This HI value is 
for one facility, which has had compliance issues with the MACT 
standards. The emissions data used in our analysis include emissions 
that are in excess of what is allowed by the MACT standards. Work is 
underway between this facility, OECA at EPA, and the State to improve 
compliance. The next highest HI from any facility in the source 
category is 0.1. Based on this, we do not anticipate that MACT-
allowable emissions for the sources in this category, or actual 
emissions when a source is in compliance with the MACT standards, would 
result in adverse chronic non-cancer health effects. Our additional 
analysis of facility-wide risks showed that the maximum facility-wide 
cancer risk is 100-in-1 million and the maximum facility-wide non-
cancer TOSHI is 10. It also showed that the steel pickling processes 
located at the facilities with these maximum risk values did not 
contribute to the cancer risk and contributed less than 1 percent to 
these non-cancer risks. Our additional analysis of the demographics of 
the exposed population may show disparities in risks between 
demographic groups. Based on this cancer risk level and in 
consideration of other health measures and factors, including the 
cancer incidence (no cases) and the low maximum non-cancer risk level 
(TOSHI of 0.2), the lack of disparate impacts in the demographic 
analysis, and the small contribution to the facility-wide risks, we 
propose that the risks from the Steel Pickling source category are 
acceptable.
b. Ample Margin of Safety
    We are proposing that the risks are acceptable, and while cancer 
risks were not above 1-in-1 million (the level at which we generally 
perform an ample margin of safety analysis), we decided to consider 
other factors before making a decision regarding the need for standards 
to reduce risks.
    Based on these analyses, we continue to propose that the current 
MACT standards provide an ample margin of safety to protect public 
health and the environment, and we are proposing to re-adopt the 
existing MACT standards to satisfy section 112(f) of the CAA.
5. What are our proposed decisions on the technology review?
    We evaluated developments in practices, processes, and control 
technologies applicable to the Steel Pickling source category. This 
included a search of the RBLC and the internet. The only advancement 
that we identified was one technology that is being used instead of 
steel pickling for some applications which is called the smooth clean 
surface (SCS) process. The SCS process uses patented roller brushes to 
remove scale from steel sheets and coils. However, this technology 
leaves the last layer of scale, resulting in a product that is rust-
resistant, but is not conducive to in-line galvanizing, painting, 
enameling or electrolytic plating. Additionally, some types of forming, 
including hydroforming, cold reduction and deep draw cannot be used 
with SCS treated steel. It is therefore not a viable replacement for 
steel pickling operations. Another technology, eco pickled surface 
(EPS), could potentially become a low-emission alternative for steel 
pickling. EPS blasts steel with an acid-free slurry which, like steel 
pickling, removes all layers of scale. However, EPS only became 
commercially available in 2009 and it is not yet a proven technology. 
Thus, it is premature to consider it as a replacement for steel 
pickling operations.
    Because we determined that the only identified development is not 
technologically feasible at this time, we are proposing that it is not 
necessary to revise the MACT standards pursuant to section 112(d)(6).
6. What other actions are we proposing?
    We propose to eliminate the SSM exemption in the Steel Pickling 
MACT standards. Consistent with Sierra Club v. EPA, EPA proposes that 
standards in this rule would apply at all times. We are proposing 
several revisions to 40 CFR part 63, subpart CCC regarding the 
standards that apply during periods of SSM. Specifically, we are 
proposing to revise Table 1 to indicate that the requirements in 40 CFR 
63.6(e) of the General Provisions do not apply. The 40 CFR 63.6(e) 
requires owner or operators to act according to the general duty to 
``operate and maintain any affected source, including associated air 
pollution control equipment and monitoring equipment, in a manner 
consistent with safety and good air pollution control practices for 
minimizing emissions.'' We are separately proposing to incorporate this 
general duty to minimize emissions into 40 CFR 63.1159(c). The 40 CFR 
63.6(e) also requires the owner or operator of an affected source to 
develop a written SSM plan. We are proposing to remove the SSM plan 
requirement. We are also proposing to revise 40 CFR 63.1161 to specify 
the conditions for performance tests, to revise the SSM-associated 
reporting and recordkeeping requirements in 40 CFR 63.1164 and 40 CFR 
63.1165 to require reporting and recordkeeping for periods of 
malfunction, and to revise Table 1 to specify that 40 CFR 63.6(f)(1), 
40 CFR 63.7(e)(1), the last sentence of 40 CFR 63.8(d)(3), 40 CFR 
63.10(b)(2)(i),(ii), (vi), and (v), 40 CFR 63.10(c)(10), (11), and 
(15), and 40 CFR 63.10(d)(5) of the General Provisions do not apply. In 
addition, we are proposing to promulgate an affirmative defense against 
civil penalties for exceedances of emission standards caused by 
malfunctions, as well as criteria for establishing the affirmative 
defense. EPA has attempted to ensure that we have not incorporated into 
proposed regulatory language any provisions that are inappropriate, 
unnecessary, or redundant in the absence of the SSM exemption. We are 
specifically seeking comment on whether there are any such provisions 
that we have inadvertently incorporated or overlooked.

[[Page 65125]]

VI. Summary of Proposed Actions

A. What actions are we proposing as a result of the technology reviews?

    For the technology review for the chromium electroplating and 
anodizing source categories, we are proposing to amend the rules to 
prohibit the addition of PFOS-based WAFS to the electroplating or 
anodizing tanks. For these source categories, we are also proposing to 
require several housekeeping requirements to minimize emissions of 
chromium-laden fugitive dust from chromium electroplating operations 
and for owners and operators to incorporate these housekeeping 
procedures in the facility operation and maintenance plan. For MTVLO, 
we are proposing to lower the existing threshold for control of 
emissions from gasoline loading from 10 million bbl/yr to 1 million 
bbl/yr.
    For the Group I Polymers and Resins, Pharmaceuticals Production, 
and Printing and Publishing Industry MACT standards, which were 
addressed in the October 10, 2008 proposal, we have reaffirmed our 
previous determinations that there have been no developments in 
practices, processes, or control technologies. Thus, we are continuing 
to propose that it is not necessary to revise the existing MACT 
requirements based on our CAA section 112(d)(6) review.
    For the Steel Pickling--HCl Process Facilities and Hydrochloric 
Acid Regeneration Plants source category, we have determined that there 
have been no developments in practices, processes, or control 
technologies since the promulgation of the MACT standards, and we are 
proposing that it is not necessary to revise the existing MACT 
requirements based on our CAA section 112(d)(6) review.

B. What actions are we proposing as a result of the residual risk 
reviews?

    For the Epichlorohydrin Elastomers Production, Hypalon\TM\ 
Production, Nitrile Butadiene Rubber Production, Polybutadiene Rubber 
Production, Styrene-Butadiene Rubber and Latex Production, MTVLO, 
Pharmaceuticals Production, and Printing and Publishing Industry MACT 
standards source categories, which were addressed in the October 10, 
2008 proposal, we have reaffirmed our proposed determinations that the 
MACT standards for these source categories provide an ample margin of 
safety to protect public health and prevent adverse environmental 
effects. Thus, we are continuing to propose to re-adopt each of these 
standards for purposes of meeting the requirements of CAA sections 
112(f)(2).
    For the Hard Chromium Electroplating, Decorative Chromium 
Electroplating, Chromium Anodizing, and Steel Pickling--HCl Process 
Facilities and Hydrochloric Acid Regeneration Plants MACT standards 
source categories, we propose that the MACT standards provide an ample 
margin of safety to protect public health and prevent adverse 
environmental effects. Thus, we are proposing to re-adopt these 
standards for the purpose of meeting the requirements of CAA section 
112(f)(2).

C. What other actions are we proposing?

    We propose to amend the Hard and Decorative Chromium Electroplating 
and Chromium Anodizing Tanks, Group I Polymers and Resins, MTVLO, 
Pharmaceuticals Production, Printing and Publishing Industry, and Steel 
Pickling--HCl Process Facilities and Hydrochloric Acid Regeneration 
Plants MACT standards to remove the language that exempts facilities 
from the emissions standards that would otherwise be applicable during 
periods of SSM, and to add an affirmative defense against civil 
penalties for exceedances of emission standards caused by malfunctions. 
These changes are being made to ensure these rules are consistent with 
the court's ruling in Sierra Club v. EPA, 551 F.3d 1019, which 
addressed similar provisions in the General Provisions that apply to 
many MACT standards.
    We are also proposing requirements for two MACT standards under the 
authority of section 112(d)(2) and (3) of the CAA to address emission 
points for which emission standards were previously not developed. For 
the MTVLO MACT standard, we are proposing to add the requirement to 
perform submerged fill for existing facilities for two subcategories, 
those emitting less than 10/25 tons of HAP, and those located more than 
0.5 miles from shore. For the Group I Polymers and Resins MACT standard 
source categories, we propose to add MACT standards limiting emissions 
from the back-end process operations from the Butyl Rubber Production 
subcategory, the Halobutyl Rubber Production subcategory, the 
Epichlorohydrin Rubber Production source category, the Nitrile 
Butadiene Rubber Production source category, and the Neoprene Rubber 
Production source category. We also propose to revise the MACT 
standards for front-end process vents from the Butyl Rubber Production 
subcategory, the Halobutyl Rubber Production subcategory, and the 
Ethylene Propylene Rubber Production source category by requiring 
control of HCl emissions resulting from the combustion of chlorinated 
organic compounds.
    In addition, we are proposing minor changes to two MACT standards 
to improve compliance and correct errors. For the Chromium 
Electroplating MACT standard source categories, we are proposing to 
clarify that testing can be performed by either Method 306 or Method 
306A, and we are proposing to revise Method 306B to correct 
inconsistencies between the amendments made to subpart N in 2004 (69 FR 
42885) and Method 306B. In addition, to eliminate a discrepancy between 
the Chromium Electroplating MACT standard and the General Provisions to 
part 63, we are also proposing to revise the trigger for semiannual 
compliance reports to be consistent with General Provisions to part 63. 
For the Pharmaceuticals Production MACT standards, we are proposing to 
correct one typographical error.

VII. Request for Comments

    We are soliciting comments on all aspects of this proposed action. 
All comments received during the comment period will be considered. In 
addition to general comments on the proposed actions, we are also 
interested in any additional data that may help to reduce the 
uncertainties inherent in the risk assessments. Such data should 
include supporting documentation in sufficient detail to allow 
characterization of the quality and representativeness of the data or 
information. Please see the following section for more information on 
submitting data.

VIII. Submitting Data Corrections

    The facility-specific data used in the source category risk 
analyses, facility-wide analyses, and demographic analyses for each 
source category subject to this action are available for download on 
the RTR Web page at http://www.epa.gov/ttn/atw/rrisk/rtrpg.html. These 
data files include detailed information for each HAP emissions release 
point at each facility included in the source category and all other 
HAP emissions sources at these facilities (facility-wide emissions 
sources). However, it is important to note that the source category 
risk analysis included only those emissions tagged with the MACT code 
associated with the source category subject to the risk analysis.
    If you believe the data are not representative or are inaccurate, 
please identify the data in question, provide your reason for concern, 
and provide any ``improved'' data that you have, if

[[Page 65126]]

available. When you submit data, we request that you provide 
documentation of the basis for the revised values to support your 
suggested changes. To submit comments on the data downloaded from the 
RTR Web page, complete the following steps:
    1. Within this downloaded file, enter suggested revisions to the 
data fields appropriate for that information. The data fields that may 
be revised include the following:

------------------------------------------------------------------------
         Data element                          Definition
------------------------------------------------------------------------
Control Measure..............  Are control measures in place? (yes or
                                no).
Control Measure Comment......  Select control measure from list
                                provided, and briefly describe the
                                control measure.
Delete.......................  Indicate here if the facility or record
                                should be deleted.
Delete Comment...............  Describes the reason for deletion.
Emission Calculation Method    Code description of the method used to
 Code For Revised Emissions.    derive emissions. For example, CEM,
                                material balance, stack test, etc.
Emission Process Group.......  Enter the general type of emission
                                process associated with the specified
                                emission point.
Fugitive Angle...............  Enter release angle (clockwise from true
                                North); orientation of the y-dimension
                                relative to true North, measured
                                positive for clockwise starting at 0
                                degrees (maximum 89 degrees).
Fugitive Length..............  Enter dimension of the source in the east-
                                west (x-) direction, commonly referred
                                to as length (ft).
Fugitive Width...............  Enter dimension of the source in the
                                north-south (y-) direction, commonly
                                referred to as width (ft).
Malfunction Emissions........  Enter total annual emissions due to
                                malfunctions (TPY).
Malfunction Emissions Max      Enter maximum hourly malfunction
 Hourly.                        emissions here (lb/hr).
North American Datum.........  Enter datum for latitude/longitude
                                coordinates (NAD27 or NAD83); if left
                                blank, NAD83 is assumed.
Process Comment..............  Enter general comments about process
                                sources of emissions.
REVISED Address..............  Enter revised physical street address for
                                MACT facility here.
REVISED City.................  Enter revised city name here.
REVISED County Name..........  Enter revised county name here.
REVISED Emission Release       Enter revised Emission Release Point Type
 Point Type.                    here.
REVISED End Date.............  Enter revised End Date here.
REVISED Exit Gas Flow Rate...  Enter revised Exit Gas Flowrate here
                                (ft\3\/sec).
REVISED Exit Gas Temperature.  Enter revised Exit Gas Temperature here
                                (F).
REVISED Exit Gas Velocity....  Enter revised Exit Gas Velocity here (ft/
                                sec).
REVISED Facility Category      Enter revised Facility Category Code
 Code.                          here, which indicates whether facility
                                is a major or area source.
REVISED Facility Name........  Enter revised Facility Name here.
REVISED Facility Registry      Enter revised Facility Registry
 Identifier.                    Identifier here, which is an ID assigned
                                by the EPA Facility Registry System.
REVISED HAP Emissions          Enter revised HAP Emissions Performance
 Performance Level Code.        Level here.
REVISED Latitude.............  Enter revised Latitude here (decimal
                                degrees).
REVISED Longitude............  Enter revised Longitude here (decimal
                                degrees).
REVISED MACT Code............  Enter revised MACT Code here.
REVISED Pollutant Code.......  Enter revised Pollutant Code here.
REVISED Routine Emissions....  Enter revised routine emissions value
                                here (TPY).
REVISED SCC Code.............  Enter revised SCC Code here.
REVISED Stack Diameter.......  Enter revised Stack Diameter here (ft).
REVISED Stack Height.........  Enter revised Stack Height here (ft).
REVISED Start Date...........  Enter revised Start Date here.
REVISED State................  Enter revised State here.
REVISED Tribal Code..........  Enter revised Tribal Code here.
REVISED Zip Code.............  Enter revised Zip Code here.
Shutdown Emissions...........  Enter total annual emissions due to
                                shutdown events (TPY).
Shutdown Emissions Max Hourly  Enter maximum hourly shutdown emissions
                                here (lb/hr).
Stack Comment................  Enter general comments about emission
                                release points.
Startup Emissions............  Enter total annual emissions due to
                                startup events (TPY).
Startup Emissions Max Hourly.  Enter maximum hourly startup emissions
                                here (lb/hr).
Year Closed..................  Enter date facility stopped operations.
------------------------------------------------------------------------

    2. Fill in the commenter information fields for each suggested 
revision (i.e., commenter name, commenter organization, commenter e-
mail address, commenter phone number, and revision comments).
    3. Gather documentation for any suggested emissions revisions 
(e.g., performance test reports, material balance calculations, etc.).
    4. Send the entire downloaded file with suggested revisions in 
Microsoft[supreg] Access format and all accompanying documentation to 
Docket ID No. EPA-HQ-OAR-2010-0600 (through one of the methods 
described in the ADDRESSES section of this preamble). To expedite 
review of the revisions, it would also be helpful if you submitted a 
copy of your revisions to the EPA directly at RTR@epa.gov in addition 
to submitting them to the docket.
    5. If you are providing comments on a facility with multiple source 
categories, you need only submit one file for that facility, which 
should contain all suggested changes for all source categories at that 
facility. We request that all data revision comments be submitted in 
the form of updated Microsoft[supreg] Access files, which are provided 
on the http://www.epa.gov/ttn/atw/rrisk/rtrpg.html Web page.

[[Page 65127]]

IX. Statutory and Executive Order Reviews

A. Executive Order 12866: Regulatory Planning and Review

    Under Executive Order 12866 (58 FR 51735, October 4, 1993), this 
action is a significant regulatory action because it raises novel legal 
and policy issues. Accordingly, EPA submitted this action to OMB for 
review under Executive Order 12866 and any changes made in response to 
OMB recommendations have been documented in the docket for this action.

B. Paperwork Reduction Act

    The information collection requirements in this rule have been 
submitted for approval to OMB under the Paperwork Reduction Act, 44 
U.S.C. 3501, et seq.
    The proposed revisions to the SSM provisions for all of the 
standards being amended with this proposed rule will reduce the 
reporting burden associated with having to prepare and submit an SSM 
report. We are not proposing any new paperwork requirements to the 
Pharmaceuticals Production, Printing and Publishing Industry, and Steel 
Pickling--HCl Process Facilities and Hydrochloric Acid Regeneration 
Plants MACT standards. Revisions and burden associated with amendments 
to the Hard and Decorative Chromium Electroplating and Chromium 
Anodizing Tanks; Group I Polymers and Resins; and MTVLO MACT standards 
are discussed in the following paragraphs. The OMB has previously 
approved the information collection requirements contained in the 
existing regulations being amended with this proposed rule (i.e., 40 
CFR part 63, subparts N, U, Y, KK, CCC, and GGG) under the provisions 
of the Paperwork Reduction Act, 44 U.S.C. 3501, et seq. The OMB control 
numbers for EPA's regulations in 40 CFR are listed in 40 CFR part 9. 
Burden is defined at 5 CFR 1320.3(b).
1. Hard and Decorative Chromium Electroplating and Chromium Anodizing 
Tanks MACT Standard
    The ICR document prepared by EPA for the amendments to the Hard and 
Decorative Chromium Electroplating and Chromium Anodizing Tanks MACT 
standards has been assigned EPA ICR number 1611.08. Burden changes 
associated with these amendments would result from new recordkeeping 
and reporting requirements associated with the new housekeeping 
requirements being proposed with today's action. The estimated average 
burden per response is 11 hours; the frequency of response is annual 
for all respondents that must comply with the rule's reporting 
requirements and the estimated average number of likely respondents per 
year is 590. The cost burden to respondents resulting from the 
collection of information includes the total capital cost annualized 
over the equipment's expected useful life (about $171,000), a total 
operation and maintenance component (about $534,000 per year), and a 
labor cost component (about $500,000 per year).
2. Group I Polymers and Resins MACT Standard
    The ICR document prepared by EPA for the amendments to the Group I 
Polymers and Resins MACT standards has been assigned EPA ICR number 
2410.01. Burden changes associated with these amendments would result 
from new recordkeeping and reporting requirements associated with the 
new back-end process operation emission limits for epichlorohydrin, 
neoprene, nitrile butadiene rubber, and butyl rubber and the HCl 
emission limits from the front-end process vents for ethylene propylene 
rubber and butyl rubber being proposed with this action. The estimated 
average burden per response is 237 hours; the frequency of response is 
annual for all respondents that must comply with the rule's reporting 
requirements and the estimated average number of likely respondents per 
year is 19. The cost burden to respondents resulting from the 
collection of information includes the total capital cost annualized 
over the equipment's expected useful life (averaging $2,800), a total 
operation and maintenance component (averaging $1,000 per year), and a 
labor cost component (averaging $1.1 million per year).
3. Marine Tank Vessel Loading Operations MACT Standard
    The ICR document prepared by EPA for the amendments to the MTVLO 
MACT standards has been assigned EPA ICR number 1679.08. Burden changes 
associated with these amendments would result from new recordkeeping 
and reporting requirements associated with the vapor recovery 
requirements being proposed with today's action. The estimated average 
burden per response is 46 hours; the frequency of response is annual 
for all respondents that must comply with the rule's reporting 
requirements and the estimated average number of likely respondents per 
year is 18. The cost burden to respondents resulting from the 
collection of information includes the total capital cost annualized 
over the equipment's expected useful life (averaging $3,780), a total 
operation and maintenance component (averaging $108 per year), and a 
labor cost component (averaging $165,000 per year).
    An agency may not conduct or sponsor, and a person is not required 
to respond to a collection of information unless it displays a 
currently valid OMB control number.
    To comment on the Agency's need for this information, the accuracy 
of the provided burden estimates, and any suggested methods for 
minimizing respondent burden, EPA has established a public docket for 
this rule, which includes these ICR, under Docket ID number EPA-HQ-OAR-
2010-0600. Submit any comments related to the ICR to EPA and OMB. See 
ADDRESSES section at the beginning of this notice for where to submit 
comments to EPA. Send comments to OMB at the Office of Information and 
Regulatory Affairs, Office of Management and Budget, 725 17th Street, 
NW., Washington, DC 20503, Attention: Desk Office for EPA. Since OMB is 
required to make a decision concerning the ICR between 30 and 60 days 
after October 21, 2010, a comment to OMB is best assured of having its 
full effect if OMB receives it by November 22, 2010. The final rule 
will respond to any OMB or public comments on the information 
collection requirements contained in this proposal.

C. Regulatory Flexibility Act

    The Regulatory Flexibility Act (RFA) generally requires an agency 
to prepare a regulatory flexibility analysis of any rule subject to 
notice and comment rulemaking requirements under the Administrative 
Procedure Act or any other statute unless the agency certifies that the 
rule will not have a significant economic impact on a substantial 
number of small entities. Small entities include small businesses, 
small organizations, and small governmental jurisdictions. For purposes 
of assessing the impacts of this proposed rule on small entities, small 
entity is defined as: (1) A small business that is a small industrial 
entity as defined by the Small Business Administration's regulations at 
13 CFR 121.201; (2) a small governmental jurisdiction that is a 
government of a city, county, town, school district or special district 
with a population of less than 50,000; and (3) a small organization 
that is any not-for-profit enterprise which is independently owned and 
operated and is not dominant in its field.
    This proposed rule will not impose emission measurements or 
reporting requirements on small entities beyond those specified in 
existing regulations, nor does it change the level of any

[[Page 65128]]

emission standard for amendments to all of the MACT standards proposed 
today, with the exception of the proposed amendments to the hard and 
decorative chromium electroplating and chromium anodizing tanks MACT 
standard. The new housekeeping requirements and PFOS use restrictions 
proposed by these amendments to the hard and decorative chromium 
electroplating and chromium anodizing tanks MACT standard may impact 
small entities, but those impacts have been estimated to be nominal.
    After considering the economic impacts of this proposed rule on 
small entities, I certify that this action will not have a significant 
economic impact on a substantial number of small entities.
    We continue to be interested in the potential impacts of the 
proposed rule on small entities and welcome comments on issues related 
to such impacts.

D. Unfunded Mandates Reform Act

    This proposed rule does not contain a Federal mandate under the 
provisions of Title II of the Unfunded Mandates Reform Act of 1995 
(UMRA), 2 U.S.C. 1531-1538 for State, local, or tribal governments or 
the private sector. The proposed rule would not result in expenditures 
of $100 million or more for State, local, and tribal governments, in 
aggregate, or the private sector in any 1 year. The proposed rule 
imposes no enforceable duties on any State, local, or tribal 
governments or the private sector. Thus, this proposed rule is not 
subject to the requirements of sections 202 or 205 of the UMRA.
    This proposed rule is also not subject to the requirements of 
section 203 of UMRA because it contains no regulatory requirements that 
might significantly or uniquely affect small governments because it 
contains no requirements that apply to such governments nor does it 
impose obligations upon them.

E. Executive Order 13132: Federalism

    This proposed rule does not have federalism implications. It will 
not have substantial direct effects on the States, on the relationship 
between the national government and the States, or on the distribution 
of power and responsibilities among the various levels of government, 
as specified in Executive Order 13132. None of the facilities subject 
to this action are owned or operated by State governments, and, because 
no new requirements are being promulgated, nothing in this proposal 
will supersede State regulations. Thus, Executive Order 13132 does not 
apply to this proposed rule.
    In the spirit of Executive Order 13132, and consistent with EPA 
policy to promote communications between EPA and State and local 
governments, EPA specifically solicits comment on this proposed rule 
from State and local officials.

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

    Subject to the Executive Order 13175 (65 FR 67249, November 9, 
2000), EPA may not issue a regulation that has tribal implications, 
that imposes substantial direct compliance costs, and that is not 
required by statute, unless the Federal government provides the funds 
necessary to pay the direct compliance costs incurred by tribal 
governments, or EPA consults with tribal officials early in the process 
of developing the proposed regulation and develops a tribal summary 
impact statement. EPA has concluded that this proposed rule will not 
have tribal implications, as specified in Executive Order 13175. It 
will not have substantial direct effect on tribal governments, on the 
relationship between the Federal government and Indian tribes, or on 
the distribution of power and responsibilities between the Federal 
government and Indian tribes, as specified in Executive Order 13175. 
Thus, Executive Order 13175 does not apply to this action.
    EPA specifically solicits additional comment on this proposed 
action from tribal officials.

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

    This proposed rule is not subject to Executive Order 13045 (62 FR 
19885, April 23, 1997) because it is not economically significant as 
defined in Executive Order 12866, and because the Agency does not 
believe the environmental health or safety risks addressed by this 
action present a disproportionate risk to children. This action would 
not relax the control measures on existing regulated sources, and EPA's 
risk assessments (included in the docket for this proposed rule) 
demonstrate that the existing regulations are health protective.

H. Executive Order 13211: Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution, or Use

    This action is not a ``significant energy action'' as defined under 
EO 13211, ``Actions Concerning Regulations That Significantly Affect 
Energy Supply, Distribution, or Use'' (66 FR 28355, May 22, 2001), 
because it is not likely to have significant adverse effect on the 
supply, distribution, or use of energy. This action will not create any 
new requirements for sources in the energy supply, distribution, or use 
sectors.

I. National Technology Transfer and Advancement Act

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

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

    Executive Order 12898 (59 FR 7629, February 16, 1994) establishes 
Federal executive policy on environmental justice. Its main provision 
directs Federal agencies, to the greatest extent practicable and 
permitted by law, to make environmental justice part of their mission 
by identifying and addressing, as appropriate, disproportionately high 
and adverse human health or environmental effects of their programs, 
policies, and activities on minority populations and low-income 
populations in the United States.
    To examine the potential for any environmental justice issues that 
might be associated with each source category, we evaluated the 
distributions of HAP-related cancer and non-cancer risks across 
different social, demographic, and economic groups within the 
populations living near the facilities where these source categories 
are located. The methods used to conduct demographic analyses for this 
rule are described in section IV.A of the preamble for this rule. The 
development of demographic analyses to inform the consideration of 
environmental justice issues in EPA rulemakings is an evolving science. 
The EPA offers the demographic analyses in this rulemaking as examples 
of how such analyses might be developed to inform such consideration, 
and invites public

[[Page 65129]]

comment on the approaches used and the interpretations made from the 
results, with the hope that this will support the refinement and 
improve utility of such analyses for future rulemakings.
    For this analysis, we analyzed risks due to the inhalation of HAP 
in two separate ways. In the first approach, we focus the analysis on 
the total populations residing within 5 km of each facility (source 
category and facility-wide), regardless of their estimated risks, and 
examine the distributions of estimated risk across the various 
demographic groups within those 5 km circles. In the other, we focus 
the analysis only on the populations within 5 km of any facility who 
are estimated to have HAP exposures which result in cancer risks of 1-
in-1 million or greater or non-cancer HI of 1 or greater (based on the 
emissions of the source category or the facility, respectively), once 
again examining the distributions of those risks across various 
demographic groups. In each approach, we compare the percentages of 
particular demographic groups to the total number of people in those 
demographic groups. In this preamble, we only present the results of 
the second approach since it focuses on the significant risks from 
either the source category or the facility-wide emissions. The results 
of both approaches are documented in memos to the docket for each of 
the source categories covered in this proposal.
    As described in the preamble, for the Epichlorohydrin Elastomers 
Production, Hypalon \TM\ Production, Nitrile Butadiene Rubber 
Production, Polybutadiene Rubber Production, Styrene-Butadiene Rubber 
and Latex Production, MTVLO, Pharmaceuticals Production, and Printing 
and Publishing Industry MACT standard source categories, which were 
addressed in the October 10, 2008, proposal, we have reaffirmed our 
proposed determinations that the MACT standards for these source 
categories provide an ample margin of safety to protect public health 
and prevent adverse environmental effects. For the Hard Chromium 
Electroplating, Decorative Chromium Electroplating, Chromium Anodizing, 
and Steel Pickling--HCl Process Facilities and Hydrochloric Acid 
Regeneration Plants MACT standard source categories, we propose the 
MACT standards provide an ample margin of safety to protect public 
health and prevent adverse environmental effects.
    Our analyses also show that, for all the source categories 
evaluated, there is no potential for an adverse environmental effect or 
human health multipathway effects, and that acute and chronic non-
cancer health impacts are unlikely. Our additional analysis of 
facility-wide risks showed that the maximum facility-wide cancer risks 
for all source categories are within the range of acceptable risks, and 
that the maximum chronic non-cancer risks are unlikely to cause health 
impacts. Our additional analysis of the demographics of the exposed 
population may show disparities in risks between demographic groups for 
all three categories; EPA has determined that, although there may be a 
disparity in risks between demographic groups, no group is exposed to 
unacceptable level of risk. The proposed rule would not relax the 
control measures on sources regulated by the rule, and, therefore, 
would not increase risks to any populations exposed to these sources.

List of Subjects in 40 CFR Part 63

    Environmental protection, Air pollution control, Reporting and 
recordkeeping requirements, Volatile organic compounds.

    Dated: September 14, 2010.
Lisa P. Jackson,
Administrator.

    For the reasons stated in the preamble, the Environmental 
Protection Agency proposes to amend title 40, chapter I of the Code of 
Federal Regulations as follows:

PART 63--[AMENDED]

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

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

Subpart N--[Amended]

    2. Section 63.341 is amended by:
    a. Adding, in alphabetical order in paragraph (a), definitions for 
``affirmative defense,'' ``contains hexavalent chromium,'' and 
``perfluorooctyl sulfonate (PFOS)-based fume suppressant''; and
    b. Revising paragraph (b)(10) to read as follows:

Sec.  63.341  Definitions and nomenclature.

    (a) * * *
    Affirmative defense means, in the context of an enforcement 
proceeding, a response or a defense put forward by a defendant, 
regarding which the defendant has the burden of proof, and the merits 
of which are independently and objectively evaluated in a judicial or 
administrative proceeding.
* * * * *
    Contains hexavalent chromium means, the substance consists of, or 
contains 0.1 percent or greater by weight, chromium trioxide, chromium 
(VI) oxide, chromic acid, or chromic anhydride.
* * * * *
    Perfluorooctyl sulfonate (PFOS)-based fume suppressant means a fume 
suppressant that contains 1 percent or greater PFOS by weight.
* * * * *
    (b) * * *
    (10) VRtot = the average total ventilation rate for the 
three test runs as determined at the outlet by means of the Method 306 
or 306A testing specified in appendix A of this part in dscm/min.
    3. Section 63.342 is amended by:
    a. Revising paragraph (a);
    b. Revising paragraph (b)(1);
    c. Adding paragraph (c)(1)(iv);
    d. Adding paragraph (c)(2)(vi);
    e. Adding paragraph (d)(3);
    f. Redesignating paragraphs (e)(2) and (e)(3) as paragraphs (e)(3) 
and (e)(4);
    g. Adding new paragraph (e)(2);
    h. Revising newly designated paragraph (e)(4);
    i. Adding paragraph (f)(3)(i)(F); and
    j. Adding Table 2 to read as follows:

Sec.  63.342  Standards.

    (a)(1) At all times, each owner or operator must operate and 
maintain any affected source subject to the requirements of this 
subpart, including associated air pollution control equipment and 
monitoring equipment, in a manner consistent with safety and good air 
pollution control practices for minimizing emissions. The general duty 
to minimize emissions does not require the owner or operator to make 
any further efforts to reduce emissions if levels required by this 
standard have been achieved. Determination of whether such operation 
and maintenance procedures are being used will be based on information 
available to the Administrator which may include, but is not limited 
to, monitoring results, review of operation and maintenance procedures, 
review of operation and maintenance records, and inspection of the 
source.
    (2) Each owner or operator of an affected source subject to the 
provisions of this subpart shall comply with these requirements in this 
section on and after the compliance dates specified in Sec.  63.343(a). 
All affected sources are regulated by applying maximum achievable 
control technology.
* * * * *
    (b) * * *
    (1) The emission limitations in this section apply during tank 
operation as defined in Sec.  63.341, and during periods of startup and 
shutdown as these are

[[Page 65130]]

routine occurrences for affected sources subject to this subpart. In 
response to an action to enforce the standards set forth in this 
subpart, you may assert a civil defense to a claim for civil penalties 
for exceedances of such standards that are caused by a malfunction, as 
defined in 40 CFR 63.2. Appropriate penalties may be assessed, however, 
if the respondent fails to meet its burden of proving all the 
requirements in the affirmative defense. The affirmative defense shall 
not be available for claims for injunctive relief.
    (i) To establish the affirmative defense in any action to enforce 
such a limit, the owners or operators of facilities must timely meet 
the notification requirements of paragraph (b)(1)(ii) of this section, 
and must prove by a preponderance of evidence that:
    (A) The excess emissions were caused by a sudden, short, 
infrequent, and unavoidable failure of air pollution control and 
monitoring equipment, or of a process to operate in a normal an usual 
manner; and could not have been prevented through careful planning, 
proper design or better operation and maintenance practices; and did 
not stem from any activity or event that could have been foreseen and 
avoided, or planned for; and were not part of a recurring pattern 
indicative of inadequate design, operation, or maintenance; and
    (B) Repairs were made as expeditiously as possible when the 
applicable emission limitations were being exceeded. Off-shift and 
overtime labor were used, to the extent practicable to make these 
repairs; and
    (C) The frequency, amount and duration of the excess emissions 
(including any bypass) were minimized to the maximum extent practicable 
during periods of such emissions; and
    (D) If the excess emissions resulted from a bypass of control 
equipment or a process, then the bypass was unavoidable to prevent loss 
of life, severe personal injury, or severe property damage; and
    (E) All possible steps were taken to minimize the impact of the 
excess emissions on ambient air quality, the environment, and human 
health; and
    (F) All emissions monitoring and control systems were kept in 
operation if at all possible; and
    (G) Your actions in response to the excess emissions were 
documented by properly signed, contemporaneous operating logs; and
    (H) At all times, the facility was operated in a manner consistent 
with good practices for minimizing emissions; and
    (I) The owner or operator has prepared a written root cause 
analysis to determine, correct and eliminate the primary causes of the 
malfunction and the excess emissions resulting from the malfunction 
event at issue. The analysis shall also specify, using the best 
monitoring methods and engineering judgment, the amount of excess 
emissions that were the result of the malfunction.
    (ii) Notification. The owner or operator of the facility 
experiencing an exceedance of its emission limit(s) during a 
malfunction shall notify the Administrator by telephone or facsimile 
(FAX) transmission as soon as possible, but no later than two business 
days after the initial occurrence of the malfunction, if it wishes to 
avail itself of an affirmative defense to civil penalties for that 
malfunction. The owner or operator seeking to assert an affirmative 
defense shall also submit a written report to the Administrator within 
30 days of the initial occurrence of the exceedance of the standard in 
this subpart to demonstrate, with all necessary supporting 
documentation, that it has met the requirements set forth in paragraph 
(b)(1)(i) of this section.
* * * * *
    (c)(1) * * *
    (iv) After 3 years from date of publication of the final rule 
amendments in the Federal Register, the owner or operator of an 
affected open surface hard chromium electroplating tank shall not add 
PFOS-based fume suppressants to any affected open surface hard chromium 
electroplating tank.
* * * * *
    (2) * * *
    (vi) After 3 years from date of publication of the final rule 
amendments in the Federal Register, the owner or operator of an 
affected enclosed hard chromium electroplating tank shall not add PFOS-
based fume suppressants to any affected enclosed hard chromium 
electroplating tank.
* * * * *
    (d) * * *
    (3) After 3 years from date of publication of the final rule 
amendments in the Federal Register, the owner or operator of an 
affected decorative chromium electroplating tank or an affected 
chromium anodizing tank shall not add PFOS-based fume suppressants to 
any affected decorative chromium electroplating tank or chromium 
anodizing tank.
    (e) * * *
    (2) After 3 years from date of publication of the final rule 
amendments in the Federal Register, the owner or operator of an 
affected decorative chromium electroplating tank using a trivalent 
chromium bath shall not add PFOS-based fume suppressants to any 
affected decorative chromium electroplating tank.
* * * * *
    (4) Each owner or operator of an existing, new, or reconstructed 
decorative chromium electroplating tank that had been using a trivalent 
chromium bath that incorporated a wetting agent and ceases using this 
type of bath must fulfill the reporting requirements of Sec.  
63.347(i)(3) and comply with the applicable emission limitation within 
the timeframe specified in Sec.  63.343(a)(7).
    (f) * * *
    (3) * * *
    (i) * * *
    (F) The plan shall include housekeeping procedures, as specified in 
Table 2 of this section.
* * * * *

                                Table 2 to Sec.   63.342--Housekeeping Practices
----------------------------------------------------------------------------------------------------------------
                 For                                You must:                     At this minimum frequency
----------------------------------------------------------------------------------------------------------------
1. Any substance that contains        (a) Store the substance in a closed   At all times.
 hexavalent chromium.                  container in an enclosed storage
                                       area; AND
                                      (b) Use a closed container when       Whenever transporting substance.
                                       transporting the substance from the
                                       enclosed storage area.
2. Each affected tank, to minimize    (a) Install drip trays that collect   Prior to operating the tank.
 spills of bath solution that result   and return to the tank any bath
 from dragout.                         solution that drips or drains from
                                       parts as the parts are removed from
                                       the tank; OR

[[Page 65131]]

                                      (b) Contain and return to the tank    Whenever removing parts from an
                                       all solution that drains or drips     affected tank.
                                       from parts as the parts are removed
                                       from the tank.
3. Each spraying operation for        Install a splash guard to minimize    Prior to any such spraying
 removing excess chromic acid from     overspray and to ensure that any      operation.
 parts removed from an affected        hexavalent chromium laden liquid is
 tank.                                 returned to the electroplating or
                                       anodizing tank.
4. Each operation that involves the   Clean up, or otherwise contain, all   Within 1 hour of the spill.
 handling or use of any substance      spills of the substance.
 that contains hexavalent chromium.
5. All surfaces within the enclosed   (a) Clean the surfaces using one or   At least once every 7 days.
 storage area, open floor area,        more of the following methods:
 walkways around affected tanks, or   (i) HEPA vacuuming;
 any surface potentially              (ii) Hand-wiping with a damp cloth;
 contaminated with hexavalent         (iii) Wet mopping;
 chromium that accumulates or         (iv) Other cleaning method approved
 potentially accumulates dust.         by the permitting agency; OR
                                      (b) Apply a non-toxic chemical dust   According to manufacturer's
                                       suppressant to the surfaces.          recommendations.
6. All buffing, grinding, or          Separate the operation from any       Prior to beginning the buffing,
 polishing operations.                 affected electroplating or            grinding, or polishing operation.
                                       anodizing operation by installing a
                                       physical barrier; the barrier may
                                       take the form of plastic strip
                                       curtains.
7. All chromium or chromium-          Store, dispose, recover, or recycle   At all times.
 containing wastes generated from      the wastes using practices that do
 housekeeping activities.              not lead to fugitive dust and in
                                       accordance with hazardous waste
                                       requirements.
----------------------------------------------------------------------------------------------------------------

    4. Section 63.343 is amended by adding paragraph (a)(8) to read as 
follows:

Sec.  63.343  Compliance provisions.

    (a) * * *
    (8) No later than 6 months from date of publication of the final 
amendments in the Federal Register, the owner or operator of an 
affected source that is subject to the standards in paragraphs Sec.  
63.342(c) or (d) shall implement the housekeeping procedures specified 
in Table 2 of Sec.  63.342.
* * * * *
    5. Section 63.344 is amended by:
    a. Revising paragraph (a);
    b. Revising paragraphs (e)(3)(iii), (e)(3)(iv), and (e)(3)(v); and
    c. Revising paragraphs (e)(4)(ii) and (e)(4)(iv) to read as 
follows:

Sec.  63.344  Performance test requirements and test methods.

    (a) Performance test requirements. Performance tests shall be 
conducted using the test methods and procedures in this section. 
Performance tests shall be conducted under such conditions as the 
Administrator specifies to the owner or operator based on 
representative performance of the affected source for the period being 
tested. Upon request, the owner or operator shall make available to the 
Administrator such records as may be necessary to determine the 
conditions of performance tests. Performance test results shall be 
documented in complete test reports that contain the information 
required by paragraphs (a)(1) through (9) of this section. The test 
plan to be followed shall be made available to the Administrator prior 
to the testing, if requested.
* * * * *
    (e) * * *
    (3) * * *
    (iii) Perform Method 306 or 306A testing and calculate an outlet 
mass emission rate.
    (iv) Determine the total ventilation rate from the affected sources 
(VRinlet) by using equation 1:
[GRAPHIC] [TIFF OMITTED] TP21OC10.000

where VRtot is the average total ventilation rate in 
dscm/min for the three test runs as determined at the outlet by 
means of the Method 306 or 306A testing; IDAi is the 
total inlet area for all ducts associated with affected sources; 
[sum]IAtotal is the sum of all inlet duct areas from both 
affected and nonaffected sources; and VRinlet is the 
total ventilation rate from all inlet ducts associated with affected 
sources.

    (v) Establish the allowable mass emission rate of the system 
(AMRsys) in milligrams of total chromium per hour (mg/hr) 
using equation 2:
[GRAPHIC] [TIFF OMITTED] TP21OC10.001

where [sum] VRinlet is the total ventilation rate in 
dscm/min from the affected sources, and EL is the applicable 
emission limitation from Sec.  63.342 in mg/dscm. The allowable mass 
emission rate (AMRsys) calculated from equation 2 should 
be equal to or

[[Page 65132]]

more than the outlet three-run average mass emission rate determined 
from Method 306 or 306A testing in order for the source to be in 
compliance with the standard.

    (4) * * *
    (ii) Determine the total ventilation rate for each type of affected 
source (VRinlet,a) using equation 3:
[GRAPHIC] [TIFF OMITTED] TP21OC10.002

where VRtot is the average total ventilation rate in 
dscm/min for the three test runs as determined at the outlet by 
means of the Method 306 or 306A testing; IDAi,a is the 
total inlet duct area for all ducts conveying chromic acid from each 
type of affected source performing the same operation, or each type 
of affected source subject to the same emission limitation; 
[sum]IAtotal is the sum of all duct areas from both 
affected and nonaffected sources; and 
VRinlet,a is the total ventilation rate from 
all inlet ducts conveying chromic acid from each type of affected 
source performing the same operation, or each type of affected 
source subject to the same emission limitation.

* * * * *
    (iv) Establish the allowable mass emission rate of the system 
(AMRsys) in milligrams of total chromium per hour (mg/hr) 
using equation 8, including each type of affected source as 
appropriate:
[GRAPHIC] [TIFF OMITTED] TP21OC10.003

The allowable mass emission rate calculated from equation 8 should be 
equal to or more than the outlet three-run average mass emission rate 
determined from Method 306 or 306A testing in order for the source to 
be in compliance with the standards.
* * * * *
    6. Section 63.346 is amended by revising paragraphs (b)(4) and 
(b)(13) to read as follows:

Sec.  63.346  Recordkeeping requirements.

* * * * *
    (b) * * *
    (4) Records of actions taken during periods of malfunction to 
minimize emissions in accordance with Sec.  63.342(a)(1), including 
corrective actions to restore malfunctioning process and air pollution 
control and monitoring equipment to its normal or usual manner of 
operation;
* * * * *
    (13) For sources using fume suppressants to comply with the 
standards, records of the date and time that fume suppressants are 
added to the electroplating or anodizing bath and records of the fume 
suppressant manufacturer and product name;
* * * * *
    7. Section 63.347 is amended by:
    a. Redesignating paragraphs (g)(3)(xii) and (g)(3)(xiii) as 
(g)(3)(xiii) and (g)(3)(xiv), respectively, and adding a new paragraph 
(g)(3)(xii);
    c. Revising paragraphs (h)(2)(i) introductory text and (h)(2)(i)(A) 
to read as follows:

Sec.  63.347  Reporting requirements.

* * * * *
    (g) * * *
    (3) * * *
    (xii) The number, duration, and a brief description for each type 
of malfunction which occurred during the reporting period and which 
caused or may have caused any applicable emission limitation to be 
exceeded. The report must also include a description of actions taken 
by an owner or operator during a malfunction of an affected source to 
minimize emissions in accordance with Sec.  63.342(a)(1), including 
actions taken to correct a malfunction.
* * * * *
    (h) * * *
    (2) * * *
    (i) If either of the following conditions is met, semiannual 
reports shall be prepared and submitted to the Administrator:
    (A) The total duration of excess emissions (as indicated by the 
monitoring data collected by the owner or operator of the affected 
source in accordance with Sec.  63.343(c)) is 1 percent or greater of 
the total operating time for the reporting period; or
* * * * *
    8. Table 1 to Subpart N is amended by:
    a. Removing entry 63.7(e);
    b. Adding entries 63.7(e)(1) and 63.7(e)(2)-(4) to read as follows:

                 Table 1 to Subpart N of Part 63--General Provisions Applicability to Subpart N
----------------------------------------------------------------------------------------------------------------
      General provisions reference            Applies to Subpart N                      Comment
----------------------------------------------------------------------------------------------------------------

                                                  * * * * * * *
63.7(e)(1)..............................  No.........................  See Sec.   63.344(a). Any cross reference
                                                                        to Sec.   63.7(e)(1) in any other
                                                                        general provision incorporated by
                                                                        reference shall be treated as a cross-
                                                                        reference to Sec.   63.344(a).
63.7(e)(2)-(4)..........................  Yes........................  Subpart N also contains test methods
                                                                        specific to affected sources covered by
                                                                        that subpart.
                                                  * * * * * * *
----------------------------------------------------------------------------------------------------------------

Subpart U--[Amended]

    9. Section 63.480 is amended by revising paragraph (j) to read as 
follows:

Sec.  63.480  Applicability and designation of affected sources.

* * * * *
    (j) Applicability of this subpart. Paragraphs (j)(1) through (4) of 
this section shall be followed during periods of non-operation of the 
affected source or any part thereof.
    (1) The emission limitations set forth in this subpart and the 
emission limitations referred to in this subpart shall apply at all 
times except during periods of non-operation of the affected source (or 
specific portion thereof) resulting in cessation of the emissions to 
which this subpart applies. However, if a period of non-operation of 
one portion of an affected source does not affect the ability of a 
particular emission point to comply with the emission limitations to 
which it is subject, then that emission

[[Page 65133]]

point shall still be required to comply with the applicable emission 
limitations of this subpart during period of non-operation.
    (2) The emission limitations set forth in subpart H of this part, 
as referred to in Sec.  63.502, shall apply at all times except during 
periods of non-operation of the affected source (or specific portion 
thereof) in which the lines are drained and depressurized resulting in 
cessation of the emissions to which Sec.  63.502 applies.
    (3) The owner or operator shall not shut down items of equipment 
that are required or utilized for compliance with this subpart during 
times when emissions (or, where applicable, wastewater streams or 
residuals) are being routed to such items of equipment if the shutdown 
would contravene requirements of this subpart applicable to such items 
of equipment.
    (4) In response to an action to enforce the standards set forth in 
this subpart, you may assert a civil defense to a claim for civil 
penalties for exceedances of such standards that are caused by a 
malfunction, as defined in 40 CFR 63.2. Appropriate penalties may be 
assessed, however, if the respondent fails to meet its burden of 
proving all the requirements in the affirmative defense. The 
affirmative defense shall not be available for claims for injunctive 
relief.
    (i) To establish the affirmative defense in any action to enforce 
such a limit, the owners or operators of facilities must timely meet 
the notification requirements of paragraph (j)(4)(ii) of this section, 
and must prove by a preponderance of evidence that:
    (A) The excess emissions were caused by a sudden, short, 
infrequent, and unavoidable failure of air pollution control and 
monitoring equipment, or a process to operate in a normal and usual 
manner; and could not have been prevented through careful planning, 
proper design, or better operation and maintenance practices; and did 
not stem from any activity or event that could have been foreseen and 
avoided, or planned for; and were not part of a recurring pattern 
indicative of inadequate design, operation, or maintenance; and
    (B) Repairs were made as expeditiously as possible when the 
applicable emission limitations were being exceeded. Off-shift and 
overtime labor were used, to the extent practicable to make these 
repairs; and
    (C) The frequency, amount, and duration of the excess emissions 
(including any bypass) were minimized to the maximum extent practicable 
during periods of such emissions; and
    (D) If the excess emissions resulted from a bypass of control 
equipment or a process, then the bypass was unavoidable to prevent loss 
of life, severe personal injury, or severe property damage; and
    (E) All possible steps were taken to minimize the impact of the 
excess emissions on ambient air quality, the environment, and human 
health; and
    (F) All emissions monitoring and control systems were kept in 
operation if at all possible; and
    (G) Your actions in response to the excess emissions were 
documented by properly signed, contemporaneous operating logs; and
    (H) At all times, the facility was operated in a manner consistent 
with good practices for minimizing emissions; and
    (I) The owner or operator has prepared a written root cause 
analysis to determine, correct, and eliminate the primary causes of the 
malfunction and the excess emissions resulting from the malfunction 
event at issue. The analysis shall also specify, using the best 
monitoring methods and engineering judgment, the amount of excess 
emissions that were the result of the malfunction.
    (ii) Notification. The owner or operator of the facility 
experiencing an exceedance of its emission limit(s) during a 
malfunction shall notify the Administrator by telephone or facsimile 
(FAX) transmission as soon as possible, but no later than 2 business 
days after the initial occurrence of the malfunction, if it wishes to 
avail itself of an affirmative defense to civil penalties for that 
malfunction. The owner or operator seeking to assert an affirmative 
defense shall also submit a written report to the Administrator within 
30 days of the initial occurrence of the exceedance of the standard in 
this subpart to demonstrate, with all necessary supporting 
documentation, that it has met the requirements set forth in paragraph 
(j)(4)(i) of this section.
    10. Section 63.481 is amended by revising paragraph (c) to read as 
follows:

Sec.  63.481  Compliance dates and relationship of this subpart to 
existing applicable rules.

* * * * *
    (c) With the exceptions provided in paragraphs (c)(1) through (4) 
of this section, existing affected sources shall be in compliance with 
this subpart no later than June 19, 2001, as provided in Sec.  63.6(c), 
unless an extension has been granted as specified in paragraph (e) of 
this section.
    (1) Existing affected sources producing epichlorohydrin elastomer, 
halobutyl rubber, neoprene rubber, and nitrile butadiene rubber shall 
be in compliance with the applicable emission limitation in Sec.  
63.494(a)(4) no later than 1 year from date of publication of the final 
rule amendments in the Federal Register.
    (2) Existing affected sources producing butyl rubber shall be in 
compliance with Sec.  63.494(a)(4)(i) no later than 3 years from date 
of publication of the final rule amendments in the Federal Register.
    (3) Existing affected sources producing butyl rubber, halobutyl 
rubber, and ethylene propylene rubber shall be in compliance with Sec.  
63.485(q)(1) no later than 3 years from date of publication of the 
final rule amendments in the Federal Register.
    (4) Compliance with Sec.  63.502 is covered by paragraph (d) of 
this section.
* * * * *
    11. Section 63.482 is amended by adding in alphabetical order a 
definition for ``affirmative defense,'' and revising the definition of 
``initial start-up'' in paragraph (b) to read as follows:

Sec.  63.482  Definitions.

* * * * *
    (b) * * *
    Affirmative defense means, in the context of an enforcement 
proceeding, a response or a defense put forward by a defendant, 
regarding which the defendant has the burden of proof, and the merits 
of which are independently and objectively evaluated in a judicial or 
administrative proceeding.
* * * * *
    Initial start-up means the first time a new or reconstructed 
affected source begins production of an elastomer product, or, for 
equipment added or changed as described in Sec.  63.480(i), the first 
time the equipment is put into operation to produce an elastomer 
product. Initial start-up does not include operation solely for testing 
equipment. Initial start-up does not include subsequent start-ups of an 
affected source or portion thereof following shutdowns or following 
changes in product for flexible operation units or following recharging 
of equipment in batch operation.
* * * * *
    12. Section 63.483 is amended by revising paragraph (a) to read as 
follows:

Sec.  63.483  Emission standards.

    (a) At all times, each owner or operator must operate and maintain 
any affected source subject to the requirements of this subpart, 
including associated air pollution control equipment and monitoring 
equipment,

[[Page 65134]]

in a manner consistent with safety and good air pollution control 
practices for minimizing emissions. The general duty to minimize 
emissions does not require the owner or operator to make any further 
efforts to reduce emissions if levels required by this standard have 
been achieved. Determination of whether such operation and maintenance 
procedures are being used will be based on information available to the 
Administrator which may include, but is not limited to, monitoring 
results, review of operation and maintenance procedures, review of 
operation and maintenance records, and inspection of the source. Except 
as allowed under paragraphs (b) through (d) of this section, the owner 
or operator of an existing or new affected source shall comply with the 
provisions in:
    (1) Section 63.484 for storage vessels;
    (2) Section 63.485 for continuous front-end process vents;
    (3) Sections 63.486 through 63.492 for batch front-end process 
vents;
    (4) Sections 63.493 through 63.500 for back-end process operations;
    (5) Section 63.501 for wastewater;
    (6) Section 63.502 for equipment leaks;
    (7) Section 63.504 for additional test methods and procedures;
    (8) Section 63.505 for monitoring levels and excursions; and
    (9) Section 63.506 for general reporting and recordkeeping 
requirements.
* * * * *
    13. Section 63.484 is amended by revising paragraph (b)(4) to read 
as follows:

Sec.  63.484  Storage vessel provisions.

* * * * *
    (b) * * *
    (4) Storage vessels located downstream of the stripping operations 
at affected sources subject to the back-end residual organic HAP 
limitation located in Sec.  63.494(a)(1) through (3), that are 
complying through the use of stripping technology, as specified in 
Sec.  63.495;
* * * * *
    14. Section 63.485 is amended by revising paragraphs (q) 
introductory text and (q)(1) introductory text to read as follows:

Sec.  63.485  Continuous front-end process vent provisions.

* * * * *
    (q) Group 1 halogenated continuous front-end process vents must 
comply with the provisions of Sec.  63.113(a)(1)(ii) and Sec.  
63.113(c), with the exceptions noted in paragraphs (q)(1) and (2) of 
this section.
    (1) All Group 1 and Group 2 halogenated continuous front-end 
process vents at existing affected sources producing butyl rubber, 
halobutyl rubber, or ethylene propylene rubber using a solution 
process, must comply with Sec.  63.113(a)(1)(ii) and Sec.  63.113(c).
* * * * *
    15. Section 63.489 is amended by revising paragraph (b)(4)(ii)(C) 
to read as follows:

Sec.  63.489  Batch front-end process vents--monitoring equipment.

* * * * *
    (b) * * *
    (4) * * *
    (ii) * * *
    (C) The owner or operator may prepare and implement a gas stream 
flow determination plan that documents an appropriate method which will 
be used to determine the gas stream flow. The plan shall require 
determination of gas stream flow by a method which will at least 
provide a value for either a representative or the highest gas stream 
flow anticipated in the scrubber during representative operating 
conditions. The plan shall include a description of the methodology to 
be followed and an explanation of how the selected methodology will 
reliably determine the gas stream flow, and a description of the 
records that will be maintained to document the determination of gas 
stream flow. The owner or operator shall maintain the plan as specified 
in Sec.  63.506(a).
* * * * *
    16. Section 63.491 is amended by revising paragraph (e)(2)(ii) to 
read as follows:

Sec.  63.491  Batch front-end process vents--recordkeeping 
requirements.

* * * * *
    (e) * * *
    (2) * * *
    (ii) Monitoring data recorded during periods of monitoring system 
breakdowns, repairs, calibration checks, and zero (low-level) and high-
level adjustments shall not be included in computing the batch cycle 
daily averages. In addition, monitoring data recorded during periods of 
non-operation of the EPPU (or specific portion thereof) resulting in 
cessation of organic HAP emissions shall not be included in computing 
the batch cycle daily averages.
* * * * *
    17. Section 63.493 is revised to read as follows:

Sec.  63.493  Back-end process provisions.

    Owners and operators of new and existing affected sources shall 
comply with the requirements in Sec. Sec.  63.494 through 63.500. 
Owners and operators of affected sources whose only elastomer products 
are latex products, liquid rubber products, or products produced in a 
gas-phased reaction process are not subject to the provisions of 
Sec. Sec.  63.494 through 63.500. If latex or liquid rubber products 
are produced in an affected source that also produces another elastomer 
product, the provisions of Sec. Sec.  63.494 through 63.500 do not 
apply to the back-end operations dedicated to the production of one or 
more latex products or to the back-end operations during the production 
of a latex product.
    18. Section 63.494 is amended by:
    a. Revising the section heading;
    b. Revising paragraph (a) introductory text;
    c. Revising paragraph (a)(4) and the introductory text of paragraph 
(a)(5);
    d. Adding paragraph (a)(6);
    e. Revising paragraph (b);
    f. Revising paragraph (c); and
    g. Revising paragraph (d) to read as follows:

Sec.  63.494  Back-end process provisions--residual organic HAP and 
emission limitations.

    (a) The monthly weighted average residual organic HAP content of 
all grades of styrene butadiene rubber produced by the emulsion 
process, polybutadiene rubber and styrene butadiene rubber produced by 
the solution process, and ethylene-propylene rubber produced by the 
solution process that is processed, shall be measured after the 
stripping operation [or the reactor(s), if the plant has no 
stripper(s)] as specified in Sec.  63.495(d), and shall not exceed the 
limits provided in paragraphs (a)(1) through (3) of this section, as 
applicable. Owners or operators of these affected sources shall comply 
with the requirements of paragraphs (a)(1) through (3) of this section 
using either stripping technology or control or recovery devices. The 
organic HAP emissions from all back-end process operations at affected 
sources producing butyl rubber, epichlorohydrin elastomer, halobutyl 
rubber, neoprene, and nitrile butadiene rubber shall not exceed the 
limits determined in accordance with paragraph (a)(4) of this section, 
as applicable.
* * * * *
    (4) The organic HAP emissions from back-end processes at affected 
sources producing butyl rubber, epichlorohydrin elastomer, halobutyl

[[Page 65135]]

rubber, neoprene, and nitrile butadiene rubber shall not exceed the 
limits determined in accordance with paragraphs (a)(4)(i) through (v) 
of this section for any consecutive 12-month period. The specific 
limitation for each elastomer type shall be determined based on the 
emissions level provided in paragraphs (a)(4)(i) through (v) of this 
section divided by the base year production level. The limitation shall 
be calculated and submitted in accordance with Sec.  63.499(f)(1).
    (i) For butyl rubber, the organic HAP emission limitation, in units 
of Mg organic HAP emissions per Mg of butyl rubber produced, shall be 
calculated by dividing 28 Mg/yr by the mass of butyl rubber produced in 
2009, in Mg.
    (ii) For epichlorohydrin elastomer, the organic HAP emission 
limitation, in units of Mg organic HAP emissions per Mg of 
epichlorohydrin elastomer produced, shall be calculated by dividing 36 
Mg/yr by the mass of epichlorohydrin elastomer produced in 2009, in Mg.
    (iii) For halobutyl rubber, the organic HAP emission limitation, in 
units of Mg organic HAP emissions per Mg of halobutyl rubber produced, 
shall be calculated by dividing 53 Mg/yr by the mass of halobutyl 
rubber produced in 2006, in Mg.
    (iv) For neoprene, the organic HAP emission limitation, in units of 
Mg organic HAP emissions per Mg of neoprene produced, shall be 
calculated by dividing 23 Mg/yr by the mass of neoprene produced in 
2009, in Mg.
    (v) For nitrile butadiene rubber, the organic HAP emission 
limitation, in units of Mg organic HAP emissions per Mg of nitrile 
butadiene rubber produced, shall be calculated by dividing 1.7 Mg/yr by 
the mass of nitrile butadiene rubber produced in 2009, in Mg.
    (5) For EPPU that produce both an elastomer product with a residual 
organic HAP limitation listed in paragraphs (a)(1) through (3) of this 
section, and a product listed in paragraphs (a)(5)(i) through (iv) of 
this section, only the residual HAP content of the elastomer product 
with a residual organic HAP limitation shall be used in determining the 
monthly average residual organic HAP content.
* * * * *
    (6) There are no back-end process operation residual organic HAP or 
emission limitations for HypalonTM and polysulfide rubber 
production. There are also no back-end process operation residual 
organic HAP limitations for latex products, liquid rubber products, 
products produced in a gas-phased reaction process, styrene butadiene 
rubber produced by any process other than a solution or emulsion 
process, polybutadiene rubber produced by any process other than a 
solution process, or ethylene-propylene rubber produced by any process 
other than a solution process.
    (b) If an owner or operator complies with the residual organic HAP 
limitations in paragraph (a)(1) through (3) of this section using 
stripping technology, compliance shall be demonstrated in accordance 
with Sec.  63.495. The owner or operator shall also comply with the 
recordkeeping provisions in Sec.  63.498, and the reporting provisions 
in Sec.  63.499.
    (c) If an owner or operator complies with the residual organic HAP 
limitations in paragraph (a)(1) through (3) of this section using 
control or recovery devices, compliance shall be demonstrated using the 
procedures in Sec.  63.496. The owner or operator shall also comply 
with the monitoring provisions in Sec.  63.497, the recordkeeping 
provisions in Sec.  63.498, and the reporting provisions in Sec.  
63.499.
    (d) If the owner or operator complies with the residual organic HAP 
limitations in paragraph (a)(1) through (3) of this section using a 
flare, the owner or operator of an affected source shall comply with 
the requirements in Sec.  63.504(c).
    19. Section 63.495 is amended by:
    a. Revising the section heading;
    b. Revising paragraph (a);
    c. Revising paragraph (b)(5); and
    d. Adding paragraph (g) to read as follows:

Sec.  63.495  Back-end process provisions--procedures to determine 
compliance with residual organic HAP limitations using stripping 
technology and organic HAP emissions limitations.

    (a) If an owner or operator complies with the residual organic HAP 
limitations in Sec.  63.494(a)(1) through (3) using stripping 
technology, compliance shall be demonstrated using the periodic 
sampling procedures in paragraph (b) of this section, or using the 
stripper parameter monitoring procedures in paragraph (c) of this 
section. The owner or operator shall determine the monthly weighted 
average residual organic HAP content for each month in which any 
portion of the back-end of an elastomer production process is in 
operation. A single monthly weighted average shall be determined for 
all back-end process operations at the affected source.
    (b) * * *
    (5) The monthly weighted average shall be determined using the 
equation in paragraph (f) of this section. All representative samples 
taken and analyzed during the month shall be used in the determination 
of the monthly weighted average.
* * * * *
    (g) Compliance with the organic HAP emission limitations determined 
in accordance with Sec.  63.494(a)(4) shall be demonstrated in 
accordance with paragraphs (g)(1) through (5) of this section.
    (1) Calculate your organic HAP emission limitation in accordance 
with Sec.  63.494(a)(4)(i) through (v), as applicable, record it, and 
submit it in accordance with Sec.  63.499(f)(1).
    (2) Each month, calculate and record the organic HAP emissions from 
all back end process operations using engineering assessment. 
Engineering assessment includes, but is not limited to, the following:
    (i) Previous test results, provided the test was representative of 
current operating practices.
    (ii) Bench-scale or pilot-scale test data obtained under conditions 
representative of current process operating conditions.
    (iii) Design analysis based on accepted chemical engineering 
principles, measurable process parameters, or physical or chemical laws 
or properties. Examples of analytical methods include, but are not 
limited to:
    (A) Use of material balances;
    (B) Estimation of flow rate based on physical equipment design, 
such as pump or blower capacities;
    (C) Estimation of organic HAP concentrations based on saturation 
conditions; and
    (D) Estimation of organic HAP concentrations based on grab samples 
of the liquid or vapor.
    (3) Each month, record the mass of elastomer product produced.
    (4) Each month, calculate and record the sums of the organic HAP 
emissions and the mass of elastomer produced for the month and the 
previous 11 months.
    (5) Each month, divide the total mass of organic HAP emitted for 
the 12-month period by the total mass of elastomer produced during the 
12-month period. This value must be recorded in accordance with Sec.  
63.498(e) and reported in accordance with Sec.  63.499(f)(2).
    20. Section 63.496 is amended by:
    a. Revising the section heading;
    b. Revising paragraph (a);
    c. Revising paragraph (c)(2); and
    d. Revising paragraph (d) to read as follows:

[[Page 65136]]

Sec.  63.496  Back-end process provisions--procedures to determine 
compliance with residual organic HAP limitations using control or 
recovery devices.

    (a) If an owner or operator complies with the residual organic HAP 
limitations in Sec.  63.494(a)(1) through (3) using control or recovery 
devices, compliance shall be demonstrated using the procedures in 
paragraphs (b) and (c) of this section. Previous test results conducted 
in accordance with paragraphs (b)(1) through (6) of this section may be 
used to determine compliance in accordance with paragraph (c) of this 
section.
* * * * *
    (c) * * *
    (2) A facility is in compliance if the average of the organic HAP 
contents calculated for all three test runs is below the residual 
organic HAP limitations in Sec.  63.494(a)(1) through (3).
    (d) An owner or operator complying with the residual organic HAP 
limitations in Sec.  63.494(a)(1) through (3) using a control or 
recovery device, shall redetermine the compliance status through the 
requirements described in paragraph (b) of this section whenever 
process changes are made. The owner or operator shall report the 
results of the redetermination in accordance with Sec.  63.499(d). For 
the purposes of this section, a process change is any action that would 
reasonably be expected to impair the performance of the control or 
recovery device. For the purposes of this section, the production of an 
elastomer with a residual organic HAP content greater than the residual 
organic HAP content of the elastomer used in the compliance 
demonstration constitutes a process change, unless the overall effect 
of the change is to reduce organic HAP emissions from the source as a 
whole. Other examples of process changes may include changes in 
production capacity or production rate, or removal or addition of 
equipment. For the purposes of this paragraph, process changes do not 
include: Process upsets; unintentional, temporary process changes; or 
changes that reduce the residual organic HAP content of the elastomer.
    21. Section 63.497 is amended by:
    a. Revising the section heading to Sec.  63.497;
    b. Revising paragraph (a) introductory text; and
    c. Revising paragraph (d) introductory text to read as follows:

Sec.  63.497  Back-end process provisions--monitoring provisions for 
control and recovery devices used to comply with residual organic HAP 
limitations.

    (a) An owner or operator complying with the residual organic HAP 
limitations in Sec.  63.494(a)(1) through (3) using control or recovery 
devices, or a combination of stripping and control or recovery devices, 
shall install the monitoring equipment specified in paragraphs (a)(1) 
through (6) of this section, as appropriate.
* * * * *
    (d) The owner or operator of an affected source with a controlled 
back-end process vent using a vent system that contains bypass lines 
that could divert a vent stream away from the control or recovery 
device used to comply with Sec.  63.494(a)(1) through (3) shall comply 
with paragraph (d)(1) or (2) of this section. Equipment such as low leg 
drains, high point bleeds, analyzer vents, open-ended valves or lines, 
and pressure relief valves needed for safety purposes are not subject 
to this paragraph.
* * * * *
    22. Section 63.498 is amended by:
    a. Revising paragraph (a) introductory text;
    b. Revising paragraph (a)(3);
    c. Adding paragraph (a)(4);
    d. Revising paragraph (b) introductory text;
    e. Revising paragraph (b)(3);
    f. Revising paragraph (c) introductory text;
    g. Revising paragraph (d) introductory text;
    h. Revising paragraph (d)(5)(ii)(B);
    i. Revising paragraph (d)(5)(ii)(E); and
    j. Adding paragraph (e) to read as follows:

Sec.  63.498  Back-end process provisions--recordkeeping.

    (a) Each owner or operator shall maintain the records specified in 
paragraphs (a)(1) through (3), and paragraphs (b) through (d) of this 
section, as appropriate.
* * * * *
    (3) If the back-end process operation is subject to a residual 
organic HAP limitation in Sec.  63.494(a)(1) through (3), whether 
compliance will be achieved by stripping technology, or by control or 
recovery devices.
    (4) If the back-end process operation is subject to an emission 
limitation in Sec.  63.494(a)(4), the organic HAP emission limitation 
calculated in accordance with Sec.  63.494(a)(4)(i) through (v), as 
applicable.
    (b) Each owner or operator of a back-end process operation using 
stripping technology to comply with a residual organic HAP limitation 
in Sec.  63.494(a)(1) through (3), and demonstrating compliance using 
the periodic sampling procedures in Sec.  63.495(b), shall maintain the 
records specified in paragraph (b)(1), and in paragraph (b)(2) or 
paragraph (b)(3) of this section, as appropriate.
* * * * *
    (3) If the organic HAP contents for all samples analyzed during a 
month are below the appropriate level in Sec.  63.494(a), the owner or 
operator may record that all samples were in accordance with the 
residual organic HAP limitations in Sec.  63.494(a)(1) through (3), 
rather than calculating and recording a monthly weighted average.
    (c) Each owner or operator of a back-end process operation using 
stripping technology to comply with a residual organic HAP limitation 
in Sec.  63.494(a)(1) through (3), and demonstrating compliance using 
the stripper parameter monitoring procedures in Sec.  63.495(c), shall 
maintain the records specified in paragraphs (c)(1) through (3) of this 
section.
* * * * *
    (d) Each owner or operator of a back-end process operation using 
control or recovery devices to comply with a residual organic HAP 
limitation in Sec.  63.494(a)(1) through (3) shall maintain the records 
specified in paragraphs (d)(1) through (5) of this section. The 
recordkeeping requirements contained in paragraphs (d)(1) through (4) 
pertain to the results of the testing required by Sec.  63.496(b), for 
each of the three required test runs.
* * * * *
    (5) * * *
    (ii) * * *
    (B) Monitoring data recorded during periods of monitoring system 
breakdowns, repairs, calibration checks, and zero (low-level) and high-
level adjustments shall not be included in computing the hourly or 
daily averages. In addition, monitoring data recorded during periods of 
non-operation of the EPPU (or specific portion thereof) resulting in 
cessation of organic HAP emissions shall not be included in computing 
the hourly or daily averages. Records shall be kept of the times and 
durations of all such periods and any other periods of process or 
control device operation when monitors are not operating.
* * * * *
    (E) For flares, records of the times and duration of all periods 
during which the pilot flame is absent shall be kept rather than daily 
averages. The records specified in this paragraph are not required 
during periods when emissions are not routed to the flare.
* * * * *
    (e) If the back-end process operation is subject to an organic HAP 
emission limitation in Sec.  63.494(a)(4), the records

[[Page 65137]]

specified in paragraphs (e)(1) through (4) of this section.
    (1) The applicable organic HAP emission limitation determined in 
accordance with Sec.  63.494(a)(4)(i) through (v).
    (2) The organic HAP emissions from all back-end process operations 
for each month, along with documentation of all calculations and other 
information used in the engineering assessment to estimate these 
emissions.
    (3) The mass of elastomer product produced each month.
    (4) The total mass of organic HAP emitted for each 12-month period 
divided by the total mass of elastomer produced during the 12-month 
period, determined in accordance with Sec.  63.495(g)(5).
    23. Section 63.499 is amended by:
    a. Revising paragraph (a)(3);
    b. Revising paragraph (b) introductory text;
    c. Revising paragraph (c) introductory text;
    d. Revising paragraph (d) introductory text; and
    e. Adding paragraph (f) to read as follows:

Sec.  63.499  Back-end process provisions--reporting.

    (a) * * *
    (3) If the back-end process operation is subject to a residual 
organic HAP limitation in Sec.  63.494(a)(1) through (3), whether 
compliance will be achieved by stripping technology, or by control or 
recovery devices.
    (b) Each owner or operator of a back-end process operation using 
stripping to comply with a residual organic HAP limitation in Sec.  
63.494(a)(1) through (3), and demonstrating compliance by stripper 
parameter monitoring, shall submit reports as specified in paragraphs 
(b)(1) and (2) of this section.
* * * * *
    (c) Each owner or operator of an affected source with a back-end 
process operation control or recovery device that shall comply with a 
residual organic HAP limitation in Sec.  63.494(a)(1) through (3) shall 
submit the information specified in paragraphs (c)(1) through (3) of 
this section as part of the Notification of Compliance Status specified 
in Sec.  63.506(e)(5).
* * * * *
    (d) Whenever a process change, as defined in Sec.  63.496(d), is 
made that causes the redetermination of the compliance status for the 
back-end process operations subject to a residual organic HAP 
limitation in Sec.  63.494(a)(1) through (3), the owner or operator 
shall submit a report within 180 days after the process change, as 
specified in Sec.  63.506(e)(7)(iii). The report shall include:
* * * * *
    (f) If the back-end process operation is subject to an organic HAP 
emission limitation in Sec.  63.494(a)(4), the owner and operator must 
submit the information specified in paragraphs (f)(1) and (2) of this 
section.
    (1) The applicable organic HAP emission limitation determined in 
accordance with Sec.  63.494(a)(4)(i) through (v) shall be submitted no 
later than 180 days from the date of publication of the final rule 
amendments in the Federal Register.
    (2) In the periodic report required to be submitted by Sec.  
63.506(e)(6), the total mass of organic HAP emitted for each of the 
rolling 12-month periods in the reporting period divided by the total 
mass of elastomer produced during the corresponding 12-month period, 
determined in accordance with Sec.  63.495(g)(5).
    24. Section 63.501 is amended by revising paragraph (c)(2) to read 
as follows:

Sec.  63.501  Wastewater provisions.

* * * * *
    (c) * * *
    (2) Back-end streams at affected sources that are subject to a 
residual organic HAP limitation in Sec.  63.494(a)(1) through (3) and 
that are complying with these limitations through the use of stripping 
technology.
    25. Section 63.502 is amended by revising paragraph (b)(4) to read 
as follows:

Sec.  63.502  Equipment leak and heat exchange system provisions.

* * * * *
    (b) * * *
    (4) Surge control vessels and bottoms receivers located downstream 
of the stripping operations at affected sources subject to the back-end 
residual organic HAP limitation located in Sec.  63.494(a)(1) through 
(3), that are complying through the use of stripping technology, as 
specified in Sec.  63.495;
* * * * *

Sec.  63.503  [Amended]

    26. Section 63.503 is amended by removing and reserving paragraph 
(f)(1).
    27. Section 63.504 is amended by revising paragraph (a)(1) 
introductory text to read as follows:

Sec.  63.504  Additional requirements for performance testing.

    (a) * * *
    (1) Performance tests shall be conducted at maximum representative 
operating conditions achievable during one of the time periods 
described in paragraph (a)(1)(i) of this section, without causing any 
of the situations described in paragraph (a)(1)(ii) of this section to 
occur. Upon request, the owner or operator shall make available to the 
Administrator such records as may be necessary to determine the 
conditions of performance tests.
* * * * *
    28. Section 63.505 is amended by:
    a. Revising paragraph (e)(4);
    b. Revising paragraph (g)(1)(v)(A);
    c. Revising paragraph (g)(1)(v)(B);
    d. Removing paragraphs (g)(1)(v)(C) through (g)(1)(v)(E);
    e. Revising paragraph (g)(2)(ii)(B); and
    f. Adding paragraph (j) to read as follows:

Sec.  63.505  Parameter monitoring levels and excursions.

* * * * *
    (e) * * *
    (4) An owner or operator complying with the residual organic HAP 
limitations in paragraphs (a)(1) through (3) of Sec.  63.494 using 
stripping, and demonstrating compliance by stripper parameter 
monitoring, shall redetermine the residual organic HAP content for all 
affected grades whenever process changes are made. For the purposes of 
this section, a process change is any action that would reasonably be 
expected to impair the performance of the stripping operation. For the 
purposes of this section, examples of process changes may include 
changes in production capacity or production rate, or removal or 
addition of equipment. For purposes of this paragraph, process changes 
do not include: Process upsets; unintentional, temporary process 
changes; or changes that reduce the residual organic HAP content of the 
elastomer.
* * * * *
    (g) * * *
    (1) * * *
    (v) * * *
    (A) Monitoring system breakdowns, repairs, calibration checks, and 
zero (low-level) and high-level adjustments; or
    (B) Periods of non-operation of the affected source (or portion 
thereof), resulting in cessation of the emissions to which the 
monitoring applies.
    (2) * * *
    (ii) * * *
    (B) Subtract the time during the periods of monitoring system 
breakdowns, repairs, calibration checks, and zero (low-level) and high-
level adjustments from the total amount of time determined in paragraph 
(g)(2)(ii)(A) of this section, to obtain the

[[Page 65138]]

operating time used to determine if monitoring data are insufficient.
* * * * *
    (j) Excursion definition for back-end operations subject to Sec.  
63.494(a)(4). An excursion means when the total mass of organic HAP 
emitted for any consecutive 12-month period divided by the total mass 
of elastomer produced during the 12-month period, determined in 
accordance with Sec.  63.495(g), is greater than the applicable 
emission limitation, determined in accordance with Sec.  
63.494(a)(4)(i) through (v) and submitted in accordance with Sec.  
63.499(f)(1).
    29. Section 63.506 is amended by:
    a. Revising paragraph (b)(1);
    b. Revising paragraph (d)(7);
    c. Revising paragraph (e)(3) introductory text;
    d. Removing and reserving paragraph (e)(3)(viii);
    e. Revising paragraph (e)(3)(ix)(B);
    f. Revising paragraph (e)(6)(iii)(E);
    g. Revising paragraph (h)(1)(i);
    h. Revising paragraph (h)(1)(ii)(C);
    i. Revising paragraph (h)(1)(iii);
    j. Revising paragraph (h)(2)(iii); and
    k. Removing and reserving paragraph (h)(2)(iv)(A) to read as 
follows:

Sec.  63.506  General recordkeeping and reporting provisions.

* * * * *
    (b) * * *
    (1) Malfunction records. Each owner or operator of an affected 
source subject to this subpart shall maintain records of the occurrence 
and duration of each malfunction of operation (i.e., process 
equipment), air pollution control equipment, or monitoring equipment. 
Each owner or operator shall maintain records of actions taken during 
periods of malfunction to minimize emissions in accordance with Sec.  
63.483(a)(1), including corrective actions to restore malfunctioning 
process and air pollution control and monitoring equipment to its 
normal or usual manner of operation.
* * * * *
    (d) * * *
    (7) Monitoring data recorded during periods identified in 
paragraphs (d)(7)(i) and (ii) of this section shall not be included in 
any average computed under this subpart. Records shall be kept of the 
times and durations of all such periods and any other periods during 
process or control device or recovery device operation when monitors 
are not operating.
    (i) Monitoring system breakdowns, repairs, calibration checks, and 
zero (low-level) and high-level adjustments; or
    (ii) Periods of non-operation of the affected source (or portion 
thereof), resulting in cessation of the emissions to which the 
monitoring applies.
* * * * *
    (e) * * *
    (3) Precompliance Report. Owners or operators of affected sources 
requesting an extension for compliance; requesting approval to use 
alternative monitoring parameters, alternative continuous monitoring 
and recordkeeping, or alternative controls; requesting approval to use 
engineering assessment to estimate emissions from a batch emissions 
episode, as described in Sec.  63.488(b)(6)(i); wishing to establish 
parameter monitoring levels according to the procedures contained in 
Sec.  63.505(c) or (d); shall submit a Precompliance Report according 
to the schedule described in paragraph (e)(3)(i) of this section. The 
Precompliance Report shall contain the information specified in 
paragraphs (e)(3)(ii) through (vii) of this section, as appropriate.
* * * * *
    (viii) [Reserved]
    (ix) * * *
    (B) Supplements to the Precompliance Report may be submitted to 
request approval to use alternative monitoring parameters, as specified 
in paragraph (e)(3)(iii) of this section; to use alternative continuous 
monitoring and recordkeeping, as specified in paragraph (e)(3)(iv) of 
this section; to use alternative controls, as specified in paragraph 
(e)(3)(v) of this section; to use engineering assessment to estimate 
emissions from a batch emissions episode, as specified in paragraph 
(e)(3)(vi) of this section; or to establish parameter monitoring levels 
according to the procedures contained in Sec.  63.505(c) or (d), as 
specified in paragraph (e)(3)(vii) of this section.
* * * * *
    (6) * * *
    (iii) * * *
    (E) The number, duration, and a brief description for each type of 
malfunction which occurred during the reporting period and which caused 
or may have caused any applicable emission limitation to be exceeded. 
The report must also include a description of actions taken by an owner 
or operator during a malfunction of an affected source to minimize 
emissions in accordance with Sec.  63.483(a)(1), including actions 
taken to correct a malfunction.
* * * * *
    (h) * * *
    (1) * * *
    (i) The monitoring system is capable of detecting unrealistic or 
impossible data during periods of normal operation (e.g., a temperature 
reading of -200 [deg]C on a boiler), and will alert the operator by 
alarm or other means. The owner or operator shall record the 
occurrence. All instances of the alarm or other alert in an operating 
day constitute a single occurrence.
    (ii) * * *
    (C) The running average reflects a period of normal operation.
    (iii) The monitoring system is capable of detecting unchanging data 
during periods of normal operation, except in circumstances where the 
presence of unchanging data is the expected operating condition based 
on past experience (e.g., pH in some scrubbers), and will alert the 
operator by alarm or other means. The owner or operator shall record 
the occurrence. All instances of the alarm or other alert in an 
operating day constitute a single occurrence.
* * * * *
    (2) * * *
    (iii) The owner or operator shall retain the records specified in 
paragraphs (h)(1)(i) through (iii) of this section, for the duration 
specified in paragraph (h) of this section. For any calendar week, if 
compliance with paragraphs (h)(1)(i) through (iii) of this section does 
not result in retention of a record of at least one occurrence or 
measured parameter value, the owner or operator shall record and retain 
at least one parameter value during a period of normal operation.
    (iv) * * *
    (A) [Reserved]
* * * * *
    30. Table 1 to Subpart U of part 63 is amended by:
    a. Removing entry 63.6(e);
    b. Revising entries 63.6(e)(1)(i) and 63.6(e)(1)(ii);
    c. Revising entry 63.6(e)(2);
    d. Adding entry 63.6(e)(3);
    e. Removing entries 63.6(e)(3)(i) through 63.6(e)(3)(ix);
    f. Revising entry 63.6(f)(1); and
    e. Revising entries 63.7(e)(1) and 63.10(d)(5)(i) to read as 
follows:

[[Page 65139]]

       Table 1 to Subpart U of Part 63--Applicability of General Provisions to Subpart U Affected Sources
----------------------------------------------------------------------------------------------------------------
                Reference                               Applies to Subpart U                    Explanation
----------------------------------------------------------------------------------------------------------------

                                                  * * * * * * *
Sec.   63.6(e)(1)(i)....................  No.............................................  See Sec.
                                                                                            63.483(a)(1) for
                                                                                            general duty
                                                                                            requirement. Any
                                                                                            cross reference to
                                                                                            Sec.   63.6(e)(1)(i)
                                                                                            in any other general
                                                                                            provision
                                                                                            incorporated by
                                                                                            reference shall be
                                                                                            treated as a cross
                                                                                            reference to Sec.
                                                                                            63.483(a)(1).
Sec.   63.6(e)(1)(ii)...................  No.............................................

                                                  * * * * * * *
Sec.   63.6(e)(2).......................  No.............................................  [Reserved.]
Sec.   63.6(e)(3).......................  No.............................................
Sec.   63.6(f)(1).......................  No.............................................

                                                  * * * * * * *
Sec.   63.7(e)(1).......................  No.............................................  See Sec.
                                                                                            63.504(a)(1). Any
                                                                                            cross-reference to
                                                                                            Sec.   63.7(e)(1) in
                                                                                            any other general
                                                                                            provision
                                                                                            incorporated by
                                                                                            reference shall be
                                                                                            treated as a cross-
                                                                                            reference to Sec.
                                                                                            63.504(a)(1).

                                                  * * * * * * *
63.10(d)(5)(i)..........................  No.............................................

                                                  * * * * * * *
----------------------------------------------------------------------------------------------------------------

Subpart Y--[Amended]

    31-32. Section 63.560 is amended by:
    a. Revising paragraphs (a)(1), (a)(2), and (a)(3);
    b. Revising paragraph (d)(6);
    c. Adding paragraph (e)(1)(iv);
    d. Amending Table 1 to Sec.  63.560 as follows:
    i. Revising entry 63.6(f)(1);
    ii. Removing entry 63.7(e);
    iii. Adding entries 63.7(e)(1) and 63.7(e)(2)-(4);
    iv. Removing entries 63.10(b)(2)(i) and (b)(2)(ii)-(iii);
    v. Adding entries 63.10(b)(2)(i)-(ii) and (b)(2)(iii);
    vi. Removing entry 63.10(c)(10)-(13); and
    vii. Adding entries 63.10(c)(10)-(11) and 63.10(c)(12)-(13) to read 
as follows:

Sec.  63.560  Applicability and designation of affected source.

    (a) * * *
    (1) The provisions of this subpart pertaining to the MACT standards 
in Sec.  63.562(b) and (d) of this subpart are applicable to existing 
and new sources with emissions of 10 or 25 tons, as that term is 
defined in Sec.  63.561, except as specified in paragraph (d) of this 
section, and are applicable to new sources with emissions less than 10 
and 25 tons, as that term is defined in Sec.  63.561, except as 
specified in paragraphs (d) and (f) of this section.
    (2) Existing sources with emissions less than 10 and 25 tons are 
not subject to the emissions standards in Sec.  63.562(b) and (d), 
except as specified in paragraph (f) of this section.
    (3) The recordkeeping requirements of Sec.  63.567(j)(4) and the 
emission estimation requirements of Sec.  63.565(l) apply to existing 
sources with emissions less than 10 and 25 tons, except as specified in 
paragraph (f) of this section.
* * * * *
    (d) * * *
    (6) The provisions of this subpart do not apply to marine tank 
vessel loading operations at existing offshore loading terminals, as 
that term is defined in Sec.  63.561, except existing offshore loading 
terminals must meet paragraphs (d)(6)(i) and (ii) of this section.
    (i) The submerged fill standards of 46 CFR 153.282, and
    (ii) The provisions of Sec.  63.562(f)(1) or Sec.  63.562(f)(2), if 
the terminal loads more than 1 million barrels (M barrels) of gasoline.
* * * * *
    (e) * * *
    (1) * * *
    (iv) New and existing sources with emissions less than 10 or 25 
tons, that load more than 1 M barrels of gasoline shall comply with the 
provisions of Sec.  63.562(f) by [DATE 3 YEARS FROM DATE OF PUBLICATION 
OF THE FINAL RULE IN THE FEDERAL REGISTER].
* * * * *

                     Table 1 of Sec.   63.560--General Provisions Applicability to Subpart Y
----------------------------------------------------------------------------------------------------------------
                Reference                     Applies to affected sources in subpart Y            Comment
----------------------------------------------------------------------------------------------------------------

                                                  * * * * * * *
63.6(f)(1)..............................  No.                                              .....................

                                                  * * * * * * *
63.7(e)(1)..............................  No.                                              See 63.563(b)(1). Any
                                                                                            cross reference to
                                                                                            63.7(e)(1) in any
                                                                                            other general
                                                                                            provision
                                                                                            incorporated by
                                                                                            reference shall be
                                                                                            treated as a cross-
                                                                                            reference to
                                                                                            63.563(b)(1).
63.7(e)(2)-(4)..........................  Yes.                                             .....................

                                                  * * * * * * *
63.10 (b)(2)(i)-(ii)....................  No.                                              .....................

[[Page 65140]]

                                                  * * * * * * *
63.10(b)(2)(iii)........................  Yes.                                             .....................

                                                  * * * * * * *
63.10(c)(10)-(11).......................  No.                                              See 63.567(m)(1) for
                                                                                            reporting
                                                                                            malfunctions. Any
                                                                                            cross-reference to
                                                                                            63.10(c)(10) or
                                                                                            63.10(c)(11) in any
                                                                                            other general
                                                                                            provision
                                                                                            incorporated by
                                                                                            reference shall be
                                                                                            treated as a cross-
                                                                                            reference to
                                                                                            63.567(m)(1).
63.10(c)(12)-(13).......................  Yes.                                             .....................

                                                  * * * * * * *
----------------------------------------------------------------------------------------------------------------

    33. Section 63.561 is amended by adding in alphabetical order a 
definition for ``affirmative defense'' to read as follows:

Sec.  63.561  Definitions.

* * * * *
    Affirmative defense means, in the context of an enforcement 
proceeding, a response or a defense put forward by a defendant, 
regarding which the defendant has the burden of proof, and the merits 
of which are independently and objectively evaluated in a judicial or 
administrative proceeding.
* * * * *
    34. Section 63.562 is amended by:
    a. Revising paragraph (a);
    b. Revising paragraph (b)(1);
    c. Revising paragraph (e) introductory text;
    d. Adding paragraph (e)(7); and
    e. Adding paragraph (f) to read as follows:

Sec.  63.562  Standards.

    (a) The emissions limitations in paragraphs (b), (c), (d) and (f) 
of this section apply during marine tank vessel loading operations.
    (b) MACT standards, except for the VMT source--(1)(i) Vapor 
collection system of the terminal. The owner or operator of a new 
source with emissions less than 10 and 25 tons, an existing or new 
source with emissions of 10 or 25 tons, and an existing source with 
emissions less than 10 and 25 tons that loads more than 1 M barrels of 
gasoline shall equip each terminal with a vapor collection system that 
is designed to collect HAP vapors displaced from marine tank vessels 
during marine tank vessel loading operations and to prevent HAP vapors 
collected at one loading berth from passing through another loading 
berth to the atmosphere, except for those commodities exempted under 
Sec.  63.560(d).
    (ii) Ship-to-shore compatibility. The owner or operator of a new 
source with emissions less than 10 and 25 tons, an existing or new 
source with emissions of 10 or 25 tons, and an existing source with 
emissions less than 10 and 25 tons that loads more than 1 million bbl/
yr of gasoline shall limit marine tank vessel loading operations to 
those vessels that are equipped with vapor collection equipment that is 
compatible with the terminal's vapor collection system, except for 
those commodities exempted under Sec.  63.560(d).
    (iii) Vapor tightness of marine vessels. The owner or operator of a 
new source with emissions less than 10 and 25 tons, an existing or new 
source with emissions of 10 or 25 tons, and an existing source with 
emissions less than 10 and 25 tons that loads more than 1 million bbl/
yr of gasoline shall limit marine tank vessel loading operations to 
those vessels that are vapor tight and to those vessels that are 
connected to the vapor collection system, except for those commodities 
exempted under Sec.  63.560(d).
* * * * *
    (e) Operation and maintenance requirements for air pollution 
control equipment and monitoring equipment for affected sources. At all 
times, owners or operators of affected sources shall operate and 
maintain a source, including associated air pollution control 
equipment, in a manner consistent with safety and good air pollution 
control practices for minimizing emissions. Determination of whether 
acceptable operation and maintenance procedures are being used will be 
based on information available to the Administrator which may include, 
but is not limited to, monitoring results, review of operation and 
maintenance procedures, review of operation and maintenance records, 
and inspection of the source.
* * * * *
    (7) In response to an action to enforce the standards set forth in 
this subpart, you may assert a civil defense to a claim for civil 
penalties for exceedances of such standards that are caused by a 
malfunction, as defined in Sec.  63.2. Appropriate penalties may be 
assessed, however, if the respondent fails to meet its burden of 
proving all the requirements in the affirmative defense. The 
affirmative defense shall not be available for claims for injunctive 
relief.
    (i) To establish the affirmative defense in any action to enforce 
such a limit, the owners or operators of facilities must timely meet 
the notification requirements of paragraph (e)(7)(ii) of this section, 
and must prove by a preponderance of evidence that:
    (A) The excess emissions were caused by a sudden, short, 
infrequent, and unavoidable failure of air pollution control and 
monitoring equipment, or a process to operate in a normal and usual 
manner; and could not have been prevented through careful planning, 
proper design or better operation and maintenance practices; and did 
not stem from any activity or event that could have been foreseen and 
avoided, or planned for; and were not part of a recurring pattern 
indicative of inadequate design, operation, or maintenance; and
    (B) Repairs were made as expeditiously as possible when the 
applicable emission limitations were being exceeded. Off-shift and 
overtime labor were used, to the extent practicable to make these 
repairs; and
    (C) The frequency, amount and duration of the excess emissions 
(including any bypass) were minimized to the maximum extent practicable 
during periods of such emissions; and
    (D) If the excess emissions resulted from a bypass of control 
equipment or a process, then the bypass was unavoidable to prevent loss 
of life, severe personal injury, or severe property damage; and
    (E) All possible steps were taken to minimize the impact of the 
excess emissions on ambient air quality, the environment, and human 
health; and
    (F) All emissions monitoring and control systems were kept in 
operation if at all possible; and

[[Page 65141]]

    (G) Your actions in response to the excess emissions were 
documented by properly signed, contemporaneous operating logs; and
    (H) At all times, the facility was operated in a manner consistent 
with good practices for minimizing emissions; and
    (I) The owner or operator has prepared a written root cause 
analysis to determine, correct and eliminate the primary causes of the 
malfunction and the excess emissions resulting from the malfunction 
event at issue. The analysis shall also specify, using the best 
monitoring methods and engineering judgment, the amount of excess 
emissions that were the result of the malfunction.
    (ii) Notification. The owner or operator of the facility 
experiencing an exceedance of its emission limit(s) during a 
malfunction shall notify the Administrator by telephone or facsimile 
(FAX) transmission as soon as possible, but no later 2 business days 
after the initial occurrence of the malfunction, if it wishes to avail 
itself of an affirmative defense to civil penalties for that 
malfunction. The owner or operator seeking to assert an affirmative 
defense shall also submit a written report to the Administrator within 
30 days of the initial occurrence of the exceedance of the standard in 
this subpart to demonstrate, with all necessary supporting 
documentation, that it has met the requirements set forth in paragraph 
(e)(7)(i) of this section.
    (f) The owner or operator of an existing source, that is not 
located at a petroleum refinery, with emissions less than 10 and 25 
tons that loads more than 1 million bbl/yr of gasoline shall:
    (1) Limit emissions to not more than 10 mg of total organic 
compounds per liter of gasoline loaded; or
    (2) Reduce captured emissions by at least 97 percent by weight.
    35. Section 63.563 is amended by revising paragraphs (a) 
introductory text and (b)(1) to read as follows:

Sec.  63.563  Compliance and performance testing.

    (a) The following procedures shall be used to determine compliance 
with the emissions limits under Sec.  63.562(b)(1), (c)(2), (d)(1), and 
(f):
* * * * *
    (b) * * *
    (1) Initial performance test. An initial performance test shall be 
conducted using the procedures listed in Sec.  63.7 of subpart A of 
this part according to the applicability in Table 1 of Sec.  63.560, 
the procedures listed in this section, and the test methods listed in 
Sec.  63.565. The initial performance test shall be conducted within 
180 days after the compliance date for the specific affected source. 
During this performance test, sources subject to MACT standards under 
Sec.  63.562(b)(2), (3), (4), and (5), and (d)(2) shall determine the 
reduction of HAP emissions, as VOC, for all combustion or recovery 
devices other than flares. Performance tests shall be conducted under 
such conditions as the Administrator specifies to the owner or operator 
based on representative performance of the affected source for the 
period being tested. Upon request, the owner or operator shall make 
available to the Administrator such records as may be necessary to 
determine the conditions of performance tests. Sources subject to RACT 
standards under Sec.  63.562(c)(3), (4), and (5), and (d)(2) shall 
determine the reduction of VOC emissions for all combustion or recovery 
devices other than flares.
* * * * *

Subpart KK--[Amended]

    36. Section 63.820 is amended by adding paragraph (c) to read as 
follows:

Sec.  63.820  Applicability.

* * * * *
    (c) In response to an action to enforce the standards set forth in 
this subpart, you may assert a civil defense to a claim for civil 
penalties for exceedances of such standards that are caused by a 
malfunction, as defined in Sec.  63.2. Appropriate penalties may be 
assessed, however, if the respondent fails to meet its burden of 
proving all the requirements in the affirmative defense. The 
affirmative defense shall not be available for claims for injunctive 
relief.
    (1) To establish the affirmative defense in any action to enforce 
such a limit, the owners or operators of facilities must timely meet 
the notification requirements of paragraph (c)(2) of this section, and 
must prove by a preponderance of evidence that:
    (i) The excess emissions were caused by a sudden, short, 
infrequent, and unavoidable failure of air pollution control and 
monitoring equipment, or a process to operate in a normal an usual 
manner; and could not have been prevented through careful planning, 
proper design or better operation and maintenance practices; and did 
not stem from any activity or event that could have been foreseen and 
avoided, or planned for; and were not part of a recurring pattern 
indicative of inadequate design, operation, or maintenance; and
    (ii) Repairs were made as expeditiously as possible when the 
applicable emission limitations were being exceeded. Off-shift and 
overtime labor were used, to the extent practicable to make these 
repairs; and
    (iii) The frequency, amount, and duration of the excess emissions 
(including any bypass) were minimized to the maximum extent practicable 
during periods of such emissions; and
    (iv) If the excess emissions resulted from a bypass of control 
equipment or a process, then the bypass was unavoidable to prevent loss 
of life, severe personal injury, or severe property damage; and
    (v) All possible steps were taken to minimize the impact of the 
excess emissions on ambient air quality, the environment, and human 
health; and
    (vi) All emissions monitoring and control systems were kept in 
operation if at all possible; and
    (vii) Your actions in response to the excess emissions were 
documented by properly signed, contemporaneous operating logs; and
    (viii) At all times, the facility was operated in a manner 
consistent with good practices for minimizing emissions; and
    (ix) The owner or operator has prepared a written root cause 
analysis to determine, correct and eliminate the primary causes of the 
malfunction and the excess emissions resulting from the malfunction 
event at issue. The analysis shall also specify, using the best 
monitoring methods and engineering judgment, the amount of excess 
emissions that were the result of the malfunction.
    (2) Notification. The owner or operator of the facility 
experiencing an exceedance of its emission limit(s) during a 
malfunction shall notify the Administrator by telephone or facsimile 
(FAX) transmission as soon as possible, but no later 2 business days 
after the initial occurrence of the malfunction, if it wishes to avail 
itself of an affirmative defense to civil penalties for that 
malfunction. The owner or operator seeking to assert an affirmative 
defense shall also submit a written report to the Administrator within 
30 days of the initial occurrence of the exceedance of the standard in 
this subpart to demonstrate, with all necessary supporting 
documentation, that it has met the requirements set forth in paragraph 
(c)(1) of this section.
    37. Section 63.822 is amended by adding in alphabetical order a 
definition for ``affirmative defense'' to paragraph (a) to read as 
follows:

Sec.  63.822  Definitions.

    (a) * * *

[[Page 65142]]

    Affirmative defense means, in the context of an enforcement 
proceeding, a response or a defense put forward by a defendant, 
regarding which the defendant has the burden of proof, and the merits 
of which are independently and objectively evaluated in a judicial or 
administrative proceeding.
* * * * *
    38. Section 63.823 is revised to read as follows:

Sec.  63.823  Standards: General.

    (a) Table 1 to this subpart provides cross references to the 40 CFR 
part 63, subpart A, general provisions, indicating the applicability of 
the general provisions requirements to this subpart KK.
    (b) Each owner or operator of an affected source subject to this 
subpart must at all times operate and maintain that affected source, 
including associated air pollution control equipment and monitoring 
equipment, in a manner consistent with safety and good air pollution 
control practices for minimizing emissions. Determination of whether 
such operation and maintenance procedures are being used will be based 
on information available to the Administrator, which may include, but 
is not limited to, monitoring results, review of operation and 
maintenance procedures, review of operation and maintenance records, 
and inspection of the source.
    39. Section 63.827 is amended by adding introductory text to read 
as follows:

Sec.  63.827  Performance test methods.

    Performance tests shall be conducted under such conditions as the 
Administrator specifies to the owner or operator based on 
representative performance of the affected source for the period being 
tested. Upon request, the owner or operator shall make available to the 
Administrator such records as may be necessary to determine the 
conditions of performance tests.
* * * * *
    40. Section 63.829 is amended by adding paragraphs (g) and (h) to 
read as follows:

Sec.  63.829  Recordkeeping requirements.

* * * * *
    (g) Each owner or operator of an affected source subject to this 
subpart shall maintain records of the occurrence and duration of each 
malfunction of operation (i.e., process equipment), air pollution 
control equipment, or monitoring equipment.
    (h) Each owner or operator of an affected source subject to this 
subpart shall maintain records of actions taken during periods of 
malfunction to minimize emissions in accordance with Sec.  63.823(b), 
including corrective actions to restore malfunctioning process and air 
pollution control and monitoring equipment to its normal or usual 
manner of operation.
    41. Section 63.830 is amended by:
    a. Removing and reserving paragraph (b)(5); and
    b. Adding paragraph (b)(6)(v) to read as follows:

Sec.  63.830  Reporting requirements.

* * * * *
    (b) * * *
    (5) [Reserved]
    (6) * * *
    (v) The number, duration, and a brief description for each type of 
malfunction which occurred during the reporting period and which caused 
or may have caused any applicable emission limitation to be exceeded. 
The report must also include a description of actions taken by an owner 
or operator during a malfunction of an affected source to minimize 
emissions in accordance with Sec.  63.823(b), including actions taken 
to correct a malfunction.
    42. Table 1 to Subpart KK of part 63 is amended by:
    a. Removing entry 63.6(e);
    b. Adding entries 63.6(e)(1)(i), 63.6(e)(1)(ii); 63.6(e)(1)(iii), 
63.6(e)(2), and 63.6(e)(3);
    c. Removing entry 63.6(f);
    d. Adding entries 63.6(f)(1) and 63.6(f)(2)-(f)(3);
    e. Removing entry 63.7;
    f. Adding entries 63.7(a)-(d), 63.7(e)(1), and 63.7(e)(2)-(e)(4);
    g. Removing entry 63.8(d)-(f);
    h. Adding entries 63.8(d)(1)-(2), 63.8(d)(3), and 63.8(e)-(f);
    i. Removing entries 63.10(b)(1)-(b)(3), 63.10(c)(10)-(c)(15), and 
63.10(d)(4)-(d)(5);
    j. Adding entries 63.10(b)(1), 63.10(b)(2)(i), 63.10(b)(2)(ii), 
63.10(b)(2)(iii), 63.10(b)(2)(iv)-(b)(2)(v), 63.10(b)(2)(vi)-
(b)(2)(xiv), 63.10(b)(3), 63.10(c)(10), 63.10(c)(11), 63.10(c)(12)-
(c)(14), 63.10(c)(15), 63.10(d)(4), and 63.10(d)(5) to read as follows:

               Table 1 to Subpart KK of Part 63--Applicability of General Provisions to Subpart KK
----------------------------------------------------------------------------------------------------------------
      General provisions reference                    Applicable to Subpart KK                    Comment
----------------------------------------------------------------------------------------------------------------

                                                  * * * * * * *
Sec.   63.6(e)(1)(i)....................  No.............................................  See 63.823(b) for
                                                                                            general duty
                                                                                            requirement. Any
                                                                                            cross-reference to
                                                                                            63.6(e)(1)(i) in any
                                                                                            other general
                                                                                            provision
                                                                                            incorporated by
                                                                                            reference shall be
                                                                                            treated as a cross-
                                                                                            reference to
                                                                                            63.823(b).
Sec.   63.6(e)(1)(ii)...................  No.............................................
Sec.   63.6(e)(1)(iii)..................  Yes............................................
Sec.   63.6(e)(2).......................  No.............................................  Section reserved.
Sec.   63.6(e)(3).......................  No.............................................
Sec.   63.6(f)(1).......................  No.............................................
Sec.   63.6(f)(2)-(f)(3)................  Yes............................................

                                                  * * * * * * *
Sec.   63.7(a)-(d)......................  Yes............................................
Sec.   63.7(e)(1).......................  No.............................................  See 63.827
                                                                                            introductory text.
                                                                                            Any cross-reference
                                                                                            to 63.7(e)(1) in any
                                                                                            other general
                                                                                            provision
                                                                                            incorporated by
                                                                                            reference shall be
                                                                                            treated as a cross-
                                                                                            reference to 63.827
                                                                                            introductory text.
Sec.   63.7(e)(2)-(e)(4)................  Yes............................................

                                                  * * * * * * *
Sec.   63.8(d)(1)-(2)...................  Yes............................................
Sec.   63.8(d)(3).......................  Yes, except for last sentence..................
Sec.   63.8(e)-(f)......................  Yes............................................

[[Page 65143]]

                                                  * * * * * * *
Sec.   63.10(b)(1)......................  Yes............................................
Sec.   63.10(b)(2)(i)...................  No.............................................
Sec.   63.10(b)(2)(ii)..................  No.............................................  See 63.829(g) for
                                                                                            recordkeeping of
                                                                                            occurrence and
                                                                                            duration of
                                                                                            malfunctions. See
                                                                                            63.829(h) for
                                                                                            recordkeeping of
                                                                                            actions taken during
                                                                                            malfunction. Any
                                                                                            cross-reference to
                                                                                            63.10(b)(2)(ii) in
                                                                                            any other general
                                                                                            provision
                                                                                            incorporated by
                                                                                            reference shall be
                                                                                            treated as a cross-
                                                                                            reference to
                                                                                            63.829(g).
Sec.   63.10(b)(2)(iii).................  Yes............................................
Sec.   63.10(b)(2)(iv)-(b)(2)(v)........  No.............................................
Sec.   63.10(b)(2)(vi)-(b)(2)(xiv)......  Yes............................................
Sec.   63.10(b)(3)......................  Yes............................................

                                                  * * * * * * *
Sec.   63.10(c)(10).....................  No.............................................  See 63.830(b)(6)(v)
                                                                                            for reporting
                                                                                            malfunctions. Any
                                                                                            cross-reference to
                                                                                            63.10(c)(10) in any
                                                                                            other general
                                                                                            provision
                                                                                            incorporated by
                                                                                            reference shall be
                                                                                            treated as a cross-
                                                                                            reference to
                                                                                            63.830(b)(6)(v).
Sec.   63.10(c)(11).....................  No.............................................  See 63.830(b)(6)(v)
                                                                                            for reporting
                                                                                            malfunctions. Any
                                                                                            cross-reference to
                                                                                            63.10(c)(11) in any
                                                                                            other general
                                                                                            provision
                                                                                            incorporated by
                                                                                            reference shall be
                                                                                            treated as a cross-
                                                                                            reference to
                                                                                            63.830(b)(6)(v).
Sec.   63.10(c)(12)-(c)(14).............  Yes............................................
Sec.   63.10(c)(15).....................  No.............................................

                                                  * * * * * * *
Sec.   63.10(d)(4)......................  Yes............................................
Sec.   63.10(d)(5)......................  No.............................................

                                                  * * * * * * *
----------------------------------------------------------------------------------------------------------------

Subpart CCC--[Amended]

    43. Section 63.1155 is amended by adding paragraph (d) to read as 
follows:

Sec.  63.1155  Applicability.

* * * * *
    (d) In response to an action to enforce the standards set forth in 
this subpart, you may assert a civil defense to a claim for civil 
penalties for exceedances of such standards that are caused by a 
malfunction, as defined in Sec.  63.2. Appropriate penalties may be 
assessed, however, if the respondent fails to meet its burden of 
proving all the requirements in the affirmative defense. The 
affirmative defense shall not be available for claims for injunctive 
relief.
    (1) To establish the affirmative defense in any action to enforce 
such a limit, the owners or operators of facilities must timely meet 
the notification requirements of paragraph (d)(2) of this section, and 
must prove by a preponderance of evidence that:
    (i) The excess emissions were caused by a sudden, short, 
infrequent, and unavoidable failure of air pollution control and 
monitoring equipment, or a process to operate in a normal an usual 
manner; and could not have been prevented through careful planning, 
proper design, or better operation and maintenance practices; and did 
not stem from any activity or event that could have been foreseen and 
avoided, or planned for; and were not part of a recurring pattern 
indicative of inadequate design, operation, or maintenance; and
    (ii) Repairs were made as expeditiously as possible when the 
applicable emission limitations were being exceeded. Off-shift and 
overtime labor were used, to the extent practicable to make these 
repairs; and
    (iii) The frequency, amount, and duration of the excess emissions 
(including any bypass) were minimized to the maximum extent practicable 
during periods of such emissions; and
    (iv) If the excess emissions resulted from a bypass of control 
equipment or a process, then the bypass was unavoidable to prevent loss 
of life, severe personal injury, or severe property damage; and
    (v) All possible steps were taken to minimize the impact of the 
excess emissions on ambient air quality, the environment, and human 
health; and
    (vi) All emissions monitoring and control systems were kept in 
operation if at all possible; and
    (vii) Your actions in response to the excess emissions were 
documented by properly signed, contemporaneous operating logs; and
    (viii) At all times, the facility was operated in a manner 
consistent with good practices for minimizing emissions; and
    (ix) The owner or operator has prepared a written root cause 
analysis to determine, correct, and eliminate the primary causes of the 
malfunction and the excess emissions resulting from the malfunction 
event at issue. The analysis shall also specify, using the best 
monitoring methods and engineering judgment, the amount of excess 
emissions that were the result of the malfunction.
    (2) Notification. The owner or operator of the facility 
experiencing an exceedance of its emission limit(s) during a 
malfunction shall notify the Administrator by telephone or facsimile 
(FAX) transmission as soon as possible, but no later 2 business days 
after the initial occurrence of the malfunction, if it wishes to avail 
itself of an affirmative defense to civil penalties for that 
malfunction. The owner or operator seeking to assert an affirmative 
defense shall also submit a written report to the Administrator within 
30 days of the initial occurrence of the exceedance of the standard in 
this subpart to demonstrate, with all necessary supporting 
documentation, that it has met the requirements set forth in paragraph 
(d)(1) of this section.
    44. Section 63.1156 is amended by adding in alphabetical order a 
definition for ``affirmative defense'' to read as follows:

[[Page 65144]]

Sec.  63.1156  Definitions.

* * * * *
    Affirmative defense means, in the context of an enforcement 
proceeding, a response or a defense put forward by a defendant, 
regarding which the defendant has the burden of proof, and the merits 
of which are independently and objectively evaluated in a judicial or 
administrative proceeding.
* * * * *
    45. Section 63.1159 is amended by adding paragraph (c) to read as 
follows:

Sec.  63.1159  Operational and equipment standards for existing, new, 
or reconstructed sources.

* * * * *
    (c) At all times, each owner or operator must operate and maintain 
any affected source subject to the requirements of this subpart, 
including associated air pollution control equipment and monitoring 
equipment, in a manner consistent with safety and good air pollution 
control practices for minimizing emissions. The general duty to 
minimize emissions does not require the owner or operator to make any 
further efforts to reduce emissions if levels required by this standard 
have been achieved. Determination of whether such operation and 
maintenance procedures are being used will be based on information 
available to the Administrator which may include, but is not limited 
to, monitoring results, review of operation and maintenance procedures, 
review of operation and maintenance records, and inspection of the 
source.
    46. Section 63.1160 is amended by revising paragraph (b) to read as 
follows:

Sec.  63.1160  Compliance dates and maintenance requirements.

* * * * *
    (b) Maintenance requirements. (1) The owner or operator shall 
prepare an operation and maintenance plan for each emission control 
device to be implemented no later than the compliance date. The plan 
shall be incorporated by reference into the source's title V permit. 
All such plans must be consistent with good maintenance practices, and, 
for a scrubber emission control device, must at a minimum:
    (i) Require monitoring and recording the pressure drop across the 
scrubber once per shift while the scrubber is operating in order to 
identify changes that may indicate a need for maintenance;
    (ii) Require the manufacturer's recommended maintenance at the 
recommended intervals on fresh solvent pumps, recirculating pumps, 
discharge pumps, and other liquid pumps, in addition to exhaust system 
and scrubber fans and motors associated with those pumps and fans;
    (iii) Require cleaning of the scrubber internals and mist 
eliminators at intervals sufficient to prevent buildup of solids or 
other fouling;
    (iv) Require an inspection of each scrubber at intervals of no less 
than 3 months with:
    (A) Cleaning or replacement of any plugged spray nozzles or other 
liquid delivery devices;
    (B) Repair or replacement of missing, misaligned, or damaged 
baffles, trays, or other internal components;
    (C) Repair or replacement of droplet eliminator elements as needed;
    (D) Repair or replacement of heat exchanger elements used to 
control the temperature of fluids entering or leaving the scrubber; and
    (E) Adjustment of damper settings for consistency with the required 
air flow.
    (v) If the scrubber is not equipped with a viewport or access hatch 
allowing visual inspection, alternate means of inspection approved by 
the Administrator may be used.
    (vi) The owner or operator shall initiate procedures for corrective 
action within 1 working day of detection of an operating problem and 
complete all corrective actions as soon as practicable. Procedures to 
be initiated are the applicable actions that are specified in the 
maintenance plan. Failure to initiate or provide appropriate repair, 
replacement, or other corrective action is a violation of the 
maintenance requirement of this subpart.
    (vii) The owner or operator shall maintain a record of each 
inspection, including each item identified in paragraph (b)(2)(iv) of 
this section, that is signed by the responsible maintenance official 
and that shows the date of each inspection, the problem identified, a 
description of the repair, replacement, or other corrective action 
taken, and the date of the repair, replacement, or other corrective 
action taken.
    (2) The owner or operator of each hydrochloric acid regeneration 
plant shall develop and implement a written maintenance program. The 
program shall require:
    (i) Performance of the manufacturer's recommended maintenance at 
the recommended intervals on all required systems and components;
    (ii) Initiation of procedures for appropriate and timely repair, 
replacement, or other corrective action within 1 working day of 
detection; and
    (iii) Maintenance of a daily record, signed by a responsible 
maintenance official, showing the date of each inspection for each 
requirement, the problems found, a description of the repair, 
replacement, or other action taken, and the date of repair or 
replacement.
    47. Section 63.1161 is amended by revising paragraph (a) 
introductory text to read as follows:

Sec.  63.1161  Performance testing and test methods.

    (a) Demonstration of compliance. The owner or operator shall 
conduct an initial performance test for each process or emission 
control device to determine and demonstrate compliance with the 
applicable emission limitation according to the requirements in Sec.  
63.7 of subpart A of this part and in this section. Performance tests 
shall be conducted under such conditions as the Administrator specifies 
to the owner or operator based on representative performance of the 
affected source for the period being tested. Upon request, the owner or 
operator shall make available to the Administrator such records as may 
be necessary to determine the conditions of performance tests.
* * * * *
    48. Section 63.1164 is amended by revising paragraph (c) to read as 
follows:

Sec.  63.1164  Reporting requirements.

* * * * *
    (c) The number, duration, and a brief description for each type of 
malfunction which occurred during the reporting period and which caused 
or may have caused any applicable emission limitation to be exceeded 
shall be stated in a semiannual report. The report must also include a 
description of actions taken by an owner or operator during a 
malfunction of an affected source to minimize emissions in accordance 
with Sec.  63.1159(c), including actions taken to correct a 
malfunction. The report, to be certified by the owner or operator or 
other responsible official, shall be submitted semiannually and 
delivered or postmarked by the 30th day following the end of each 
calendar half.
    49. Section 63.1165 is amended by:
    a. Revising paragraph (a)(1);
    b. Revising paragraph (a)(4);
    c. Removing paragraph (a)(5) and redesignating paragraphs (a)(6) 
through (a)(11) as paragraphs (a)(5) through (a)(10) to read as 
follows:

Sec.  63.1165  Recordkeeping requirements.

    (a) * * *
    (1) The occurrence and duration of each malfunction of operation 
(i.e., process equipment);
* * * * *

[[Page 65145]]

    (4) Actions taken during periods of malfunction to minimize 
emissions in accordance with Sec.  63.1259(c) and the dates of such 
actions (including corrective actions to restore malfunctioning process 
and air pollution control equipment to its normal or usual manner of 
operation);
* * * * *
    50. Table 1 to Subpart CCC is amended by:
    a. Removing entry 63.6(a)-(g);
    b. Adding entries 63.6(a)-(d), 63.6(e)(1)(i), 63.6(e)(1)(ii), 
63.6(e)(1)(iii), 63.6(e)(2), 63.6(e)(3), 63.6(f)(1), 63.6(f)(2)-(3), 
63.6(g);
    c. Removing entry 63.7-63.9;
    d. Adding entries 63.7, 63.8(a)-(c), 63.8(d)(1)-(2), 63.8(d)(3), 
and 63.8(e)-(f);
    e. Removing entry 63.10(a)-(c);
    f. Adding entries 63.10(a), 63.10(b)(1), 63.10(b)(2)(i), 
63.10(b)(2)(ii), 63.10(b)(2)(iii), 63.10(b)(2)(iv)-(v), 
63.10(b)(2)(vi)-(xvi), 63.10(b)(3), 63.10(c)(1)-(9), 63.10(c)(10), 
63.10(c)(11), 63.10(c)(12)-(14), and 63.10(c)(15);
    g. Removing entry 63.10(d)(4)-(5);
    h. Adding entries 63.10(d)(4) and 63.10(d)(5) to read as follows:

  Table 1 to Subpart CCC of Part 63--Applicability of General Provisions (40 CFR Part 63, Subpart A) to Subpart
                                                       CCC
----------------------------------------------------------------------------------------------------------------
                Reference                              Applies to Subpart CCC                   Explanation
----------------------------------------------------------------------------------------------------------------

                                                  * * * * * * *
63.6 (a)-(d)............................  Yes............................................
63.6(e)(1)(i)...........................  No.............................................  See Sec.   63.1259(c)
                                                                                            for general duty
                                                                                            requirement. Any
                                                                                            cross-reference to
                                                                                            Sec.   63.6(e)(1)(i)
                                                                                            in any other general
                                                                                            provision
                                                                                            incorporated by
                                                                                            reference shall be
                                                                                            treated as a cross-
                                                                                            reference to Sec.
                                                                                            63.1259(c).
63.6(e)(1)(ii)..........................  No.............................................
63.6(e)(1)(iii).........................  Yes............................................
63.6(e)(2)..............................  No.............................................  Section reserved.
63.6(e)(3)..............................  No.............................................
63.6(f)(1)..............................  No.............................................
63.6(f)(2)-(3)..........................  Yes............................................
63.6(g).................................  Yes............................................

                                                  * * * * * * *
63.7....................................  Yes............................................
63.8(a)-(c).............................  Yes............................................
63.8(d)(1)-(2)..........................  Yes............................................
63.8(d)(3)..............................  Yes, except for last sentence..................
63.8(e)-(f).............................  Yes............................................

                                                  * * * * * * *
63.10(a)................................  Yes............................................
63.10(b)(1).............................  Yes............................................
63.10(b)(2)(i)..........................  No.............................................
63.10(b)(2)(ii).........................  No.............................................  See Sec.
                                                                                            63.1265(a)(1) for
                                                                                            recordkeeping of
                                                                                            occurrence and
                                                                                            duration of
                                                                                            malfunctions. See
                                                                                            Sec.   63.1265(a)(4)
                                                                                            for recordkeeping of
                                                                                            actions taken during
                                                                                            malfunction. Any
                                                                                            cross-reference to
                                                                                            Sec.
                                                                                            63.10(b)(2)(ii) in
                                                                                            any other general
                                                                                            provision
                                                                                            incorporated by
                                                                                            reference shall be
                                                                                            treated as a cross-
                                                                                            reference to Sec.
                                                                                            63.1265(a)(1).
63.10(b)(2)(iii)........................  Yes............................................
63.10(b)(2)(iv)-(v).....................  No.............................................
63.10(b)(2)(vi)-(xiv)...................  Yes............................................
63.10(b)(3).............................  Yes............................................

                                                  * * * * * * *
63.10(c)(1)-(9).........................  Yes............................................
63.10(c)(10)............................  No.............................................  See Sec.   63.1164(c)
                                                                                            for reporting
                                                                                            malfunctions. Any
                                                                                            cross-reference to
                                                                                            Sec.   63.10(c)(10)
                                                                                            in any other general
                                                                                            provision
                                                                                            incorporated by
                                                                                            reference shall be
                                                                                            treated as a cross-
                                                                                            reference to Sec.
                                                                                            63.1164(c).
63.10(c)(11)............................  No.............................................  See Sec.   63.1164(c)
                                                                                            for reporting
                                                                                            malfunctions. Any
                                                                                            cross-reference to
                                                                                            Sec.   63.10(c)(11)
                                                                                            in any other general
                                                                                            provision
                                                                                            incorporated by
                                                                                            reference shall be
                                                                                            treated as a cross-
                                                                                            reference to Sec.
                                                                                            63.1164(c).
63.10(c)(12)-(c)(14)....................  Yes............................................
63.10(c)(15)............................  No.............................................
63.10(d)(4).............................  Yes............................................
63.10(d)(5).............................  No.............................................

                                                  * * * * * * *
----------------------------------------------------------------------------------------------------------------

Subpart GGG--[Amended]

    51. Section 63.1250 is amended by revising paragraph (g) to read as 
follows:

Sec.  63.1250  Applicability.

* * * * *
    (g) Applicability of this subpart. (1) Each provision set forth in 
this subpart shall apply at all times, except that the provisions set 
forth in Sec.  63.1255 of this subpart shall not apply during periods 
of nonoperation of the PMPU (or specific portion thereof) in which the 
lines are drained and depressurized

[[Page 65146]]

resulting in the cessation of the emissions to which Sec.  63.1255 of 
this subpart applies.
    (2) The owner or operator shall not shut down items of equipment 
that are required or utilized for compliance with the emissions 
limitations of this subpart during times when emissions (or, where 
applicable, wastewater streams or residuals) are being routed to such 
items of equipment, if the shutdown would contravene emissions 
limitations of this subpart applicable to such items of equipment. This 
paragraph does not apply if the owner or operator must shut down the 
equipment to avoid damage to a PMPU or portion thereof.
    (3) At all times, each owner or operator must operate and maintain 
any affected source subject to the requirements of this subpart, 
including associated air pollution control equipment and monitoring 
equipment, in a manner consistent with safety and good air pollution 
control practices for minimizing emissions. The general duty to 
minimize emissions does not require the owner or operator to make any 
further efforts to reduce emissions if levels required by this standard 
have been achieved. Determination of whether such operation and 
maintenance procedures are being used will be based on information 
available to the Administrator which may include, but is not limited 
to, monitoring results, review of operation and maintenance procedures, 
review of operation and maintenance records, and inspection of the 
source.
    (4) In response to an action to enforce the standards set forth in 
this subpart, you may assert a civil defense to a claim for civil 
penalties for exceedances of such standards that are caused by a 
malfunction, as defined in Sec.  63.2. Appropriate penalties may be 
assessed, however, if the respondent fails to meet its burden of 
proving all the requirements in the affirmative defense. The 
affirmative defense shall not be available for claims for injunctive 
relief.
    (i) To establish the affirmative defense in any action to enforce 
such a limit, the owners or operators of facilities must timely meet 
the notification requirements of paragraph (g)(4)(ii) of this section, 
and must prove by a preponderance of evidence that:
    (A) The excess emissions were caused by a sudden, short, 
infrequent, and unavoidable failure of air pollution control and 
monitoring equipment, or a process to operate in a normal and usual 
manner; and could not have been prevented through careful planning, 
proper design, or better operation and maintenance practices; and did 
not stem from any activity or event that could have been foreseen and 
avoided, or planned for; and were not part of a recurring pattern 
indicative of inadequate design, operation, or maintenance; and
    (B) Repairs were made as expeditiously as possible when the 
applicable emission limitations were being exceeded. Off-shift and 
overtime labor were used, to the extent practicable to make these 
repairs; and
    (C) The frequency, amount, and duration of the excess emissions 
(including any bypass) were minimized to the maximum extent practicable 
during periods of such emissions; and
    (D) If the excess emissions resulted from a bypass of control 
equipment or a process, then the bypass was unavoidable to prevent loss 
of life, severe personal injury, or severe property damage; and
    (E) All possible steps were taken to minimize the impact of the 
excess emissions on ambient air quality, the environment, and human 
health; and
    (F) All emissions monitoring and control systems were kept in 
operation if at all possible; and
    (G) Your actions in response to the excess emissions were 
documented by properly signed, contemporaneous operating logs; and
    (H) At all times, the facility was operated in a manner consistent 
with good practices for minimizing emissions; and
    (I) The owner or operator has prepared a written root cause 
analysis to determine, correct, and eliminate the primary causes of the 
malfunction and the excess emissions resulting from the malfunction 
event at issue. The analysis shall also specify, using the best 
monitoring methods and engineering judgment, the amount of excess 
emissions that were the result of the malfunction.
    (ii) Notification. The owner or operator of the facility 
experiencing an exceedance of its emission limit(s) during a 
malfunction shall notify the Administrator by telephone or facsimile 
(FAX) transmission as soon as possible, but no later 2 business days 
after the initial occurrence of the malfunction, if it wishes to avail 
itself of an affirmative defense to civil penalties for that 
malfunction. The owner or operator seeking to assert an affirmative 
defense shall also submit a written report to the Administrator within 
30 days of the initial occurrence of the exceedance of the standard in 
this subpart to demonstrate, with all necessary supporting 
documentation, that it has met the requirements set forth in paragraph 
(g)(4)(i) of this section.
* * * * *
    52. Section 63.1251 is amended by adding in alphabetical order a 
definition for ``affirmative defense'' to read as follow:

Sec.  63.1251  Definitions.

* * * * *
    Affirmative defense means, in the context of an enforcement 
proceeding, a response or a defense put forward by a defendant, 
regarding which the defendant has the burden of proof, and the merits 
of which are independently and objectively evaluated in a judicial or 
administrative proceeding.
* * * * *
    53. Section 63.1255 is amended by revising paragraph (g)(4)(v)(A) 
to read as follow:

Sec.  63.1255  Standards: Equipment leaks.

* * * * *
    (g) * * *
    (4) * * *
    (v) * * *
    (A) The owner or operator may develop a written procedure that 
identifies the conditions that justify a delay of repair. The written 
procedures shall be included in a document that is maintained at the 
plant site. Reasons for delay of repair may be documented by citing the 
relevant sections of the written procedure.
* * * * *
    54. Section 63.1256 is amended by revising paragraph (a)(4)(i) 
introductory text, and removing paragraphs (a)(4)(iii) and (iv) to read 
as follows:

Sec.  63.1256  Standards: Wastewater.

* * * * *
    (a) * * *
    (4) * * *
    (i) The owner or operator shall prepare a description of 
maintenance procedures for management of wastewater generated from the 
emptying and purging of equipment in the process during temporary 
shutdowns for inspections, maintenance, and repair (i.e., a maintenance 
turnaround) and during periods which are not shutdowns (i.e., routine 
maintenance). The descriptions shall be included in a document that is 
maintained at the plant site and shall:
* * * * *
    55. Section 63.1257 is amended by revising paragraph (a) 
introductory text and the first sentence of paragraph 
(e)(2)(iii)(A)(6)(ii) to read as follows:

Sec.  63.1257  Test methods and compliance procedures.

    (a) General. Except as specified in paragraph (a)(5) of this 
section, the procedures specified in paragraphs (c), (d), (e), and (f) 
of this section are

[[Page 65147]]

required to demonstrate initial compliance with Sec. Sec.  63.1253, 
63.1254, 63.1256, and 63.1252(e), respectively. The provisions in 
paragraphs (a)(2) through (3) apply to performance tests that are 
specified in paragraphs (c), (d), and (e) of this section. The 
provisions in paragraph (a)(5) of this section are used to demonstrate 
initial compliance with the alternative standards specified in 
Sec. Sec.  63.1253(d) and 63.1254(c). The provisions in paragraph 
(a)(6) of this section are used to comply with the outlet concentration 
requirements specified in Sec. Sec.  63.1253(c), 63.1254(a)(2)(i), and 
(a)(3)(ii)(B), 63.1254(b)(i), and 63.1256(h)(2). Performance tests 
shall be conducted under such conditions as the Administrator specifies 
to the owner or operator based on representative performance of the 
affected source for the period being tested. Upon request, the owner or 
operator shall make available to the Administrator such records as may 
be necessary to determine the conditions of performance tests.
* * * * *
    (e) * * *
    (2) * * *
    (iii) * * *
    (A) * * *
    (6) * * *
    (ii) The owner or operator may consider the inlet to the 
equalization tank as the inlet to the biological treatment process if 
the wastewater is conveyed by hard-piping from either the last previous 
treatment process or the point of determination to the equalization 
tank; and the wastewater is conveyed from the equalization tank 
exclusively by hard-piping to the biological treatment process and no 
treatment processes or other waste management units are used to store, 
handle, or convey the wastewater between the equalization tank and the 
biological treatment process; and the equalization tank is equipped 
with a fixed roof and a closed-vent system that routes emissions to a 
control device that meets the requirements of Sec.  63.1256(b)(1)(i) 
through (iv) and Sec.  63.1256(b)(2)(i). * * *
* * * * *

Sec.  63.1258  [Amended]

    56. Section 63.1258 is amended by removing paragraph (b)(8)(iv).
    57. Section 63.1259 is amended by revising paragraph (a)(3) to read 
as follows:

Sec.  63.1259  Recordkeeping requirements.

* * * * *
    (a) * * *
    (3) Malfunction records. Each owner or operator of an affected 
source subject to this subpart shall maintain records of the occurrence 
and duration of each malfunction of operation (i.e., process 
equipment), air pollution control equipment, or monitoring equipment. 
Each owner or operator shall maintain records of actions taken during 
periods of malfunction to minimize emissions in accordance with Sec.  
63.1250(g)(3), including corrective actions to restore malfunctioning 
process and air pollution control and monitoring equipment to its 
normal or usual manner of operation.
* * * * *
    58. Section 63.1260 is amended by revising paragraph (i) to read as 
follows:

Sec.  63.1260  Reporting requirements.

* * * * *
    (i) The number, duration, and a brief description for each type of 
malfunction which occurred during the reporting period and which caused 
or may have caused any applicable emission limitation to be exceeded. 
The report must also include a description of actions taken by an owner 
or operator during a malfunction of an affected source to minimize 
emissions in accordance with Sec.  63.1250(g)(3), including actions 
taken to correct a malfunction.
* * * * *
    59. Table 1 to Subpart GGG is amended by:
    a. Removing entry 63.6(e);
    b. Adding entries 63.6(e)(1)(i), 63.6(e)(1)(ii), 63.6(e)(1)(iii), 
63.6(e)(2), and 63.6(e)(3);
    c. Removing entry 63.6(f)-(g);
    d. Adding entries 63.6(f)(1), 63.6(f)(2)-(3), 63.6(g);
    e. Removing entry 63.7(e);
    f. Adding entries 63.7(e)(1) and 63.7(e)(2)-(4);
    g. Removing entry 63.8(d);
    h. Adding entries 63.8(d)(1)-(2) and 63.8(d)(3).
    i. Removing entry 63.10(c)-(d)(2);
    j. Adding entries 63.10(c)(1)-(9), 63.10(c)(10), 63.10(c)(11), 
63.10(c)(12)-(14), 63.10(c)(15), and 63.10(d)(1)-(2);
    k. Removing entry 63.10(d)(4-5); and
    l. Adding entries 63.10(d)(4) and 63.10(d)(5) to read as follows:

               Table 1 to Subpart GGG of Part 63--General Provisions Applicability to Subpart GGG
----------------------------------------------------------------------------------------------------------------
 General provisions reference    Summary of requirements      Applies to Subpart GGG             Comments
----------------------------------------------------------------------------------------------------------------

                                                  * * * * * * *
Sec.   63.6(e)(1)(i)..........  Requirements during       No...........................  See 63.1250(g)(3) for
                                 periods of startup,                                      general duty
                                 shutdown, and                                            requirement. Any cross-
                                 malfunction.                                             reference to
                                                                                          63.6(e)(1)(i) in any
                                                                                          other general
                                                                                          provision incorporated
                                                                                          by reference shall be
                                                                                          treated as a cross-
                                                                                          reference to
                                                                                          63.1250(g)(3).
Sec.   63.6(e)(1)(ii).........  Malfunction correction    No...........................
                                 requirements.
Sec.   63.6(e)(1)(iii)........  Enforceability of         Yes..........................
                                 operation and
                                 maintenance
                                 requirements.
Sec.   63.6(e)(2).............  Reserved................  No...........................  Section reserved.
Sec.   63.6(e)(3).............  Startup, shutdown, and    No...........................
                                 malfunction plan
                                 requirements.

                                                  * * * * * * *
63.6(f)(1)....................  Applicability of          No...........................
                                 nonopacity emission
                                 standards.
63.6(f)(2)-(3)................  Methods of determining    Yes..........................
                                 compliance and findings
                                 compliance.
63.6(g).......................  Use of an alternative     Yes..........................
                                 nonopacity emission
                                 standard.

[[Page 65148]]

                                                  * * * * * * *
63.7(e)(1)....................  Conduct of performance    No...........................  See 63.1257(a) text.
                                 tests.                                                   Any cross-reference to
                                                                                          63.7(e)(1) in any
                                                                                          other general
                                                                                          provision incorporated
                                                                                          by reference shall be
                                                                                          treated as a cross-
                                                                                          reference to
                                                                                          63.1257(a).
63.7 (e)(2)-(4)...............  Performance tests         Yes..........................
                                 requirements.

                                                  * * * * * * *
63.8(d)(1)-(2)................  CMS quality control       Yes..........................
                                 program requirements.
63.8(d)(3)....................  CMS quality control       Yes, except for last sentence
                                 program recordkeeping
                                 requirements.

                                                  * * * * * * *
63.10(c)(1)-(9)...............  Additional recordkeeping  Yes..........................
                                 requirements for
                                 sources with continuous
                                 monitoring systems.
63.10(c)(10)..................  Malfunction               No...........................  Subpart GGG specifies
                                 recordkeeping                                            recordkeeping
                                 requirement.                                             requirements.
63.10(c)(11)..................  Malfunction corrective    No...........................  Subpart GGG specifies
                                 action recordkeeping                                     recordkeeping
                                 requirement.                                             requirements.
63.10(c)(12)-(14).............  Additional recordkeeping  Yes..........................
                                 requirements for
                                 sources with continuous
                                 monitoring systems.
63.10(c)(15)..................  Additional SSM            No...........................
                                 recordkeeping
                                 requirements.

                                                  * * * * * * *
63.10(d)(1)-(2)...............  General reporting         Yes..........................
                                 requirements.

                                                  * * * * * * *
63.10(d)(4)...................  Progress report           Yes..........................
                                 requirements.
63.10(d)(5)...................  Startup, shutdown, and    No...........................  Subpart GGG specifies
                                 malfunction report                                       reporting
                                 requirements.                                            requirements.

                                                  * * * * * * *
----------------------------------------------------------------------------------------------------------------

    60. Appendix A to part 63, Method 306-B is amended by:
    a. Revising paragraph 1.2;
    b. Revising paragraph 6.1;
    c. Revising paragraph 11.1;
    d. Adding paragraphs 11.1.1 through 11.1.4.10; and
    e. Revising paragraph 11.2.2 to read as follows:

Appendix A to Part 63--Test Methods

Method 306B--Surface Tension Measurement for Tanks Used at Decorative 
Chromium Electroplating and Chromium Anodizing Facilities

* * * * *
    1.2 Applicability. This method is applicable to all chromium 
electroplating and chromium anodizing operations, and continuous 
chromium plating at iron and steel facilities where a wetting agent 
is used in the tank as the primary mechanism for reducing emissions 
from the surface of the plating solution.
* * * * *
    6.1 Stalagmometer. Any commercially available stalagmometer or 
equivalent surface tension measuring device may be used to measure 
the surface tension of the plating or anodizing tank liquid provided 
the procedures specified in Section 11.1.2 are followed.
* * * * *
    11.1 Procedure. The surface tension of the tank bath may be 
measured using a tensiometer, stalagmometer, or any other equivalent 
surface tension measuring device for measuring surface tension in 
dynes per centimeter.
    11.1.1 If a tensiometer is used, the procedures specified in 
ASTM Method D 1331-89 must be followed.
    11.1.2 If a stalagmometer is used, the procedures specified in 
Sections 11.1.2.1 through 11.1.2.3 must be followed.
    11.1.2.1 Check the stalagmometer for visual signs of damage. If 
the stalagmometer appears to be chipped, cracked, or otherwise in 
disrepair, the instrument shall not be used.
    11.1.2.2 Using distilled or deionized water and following the 
procedures provided by the manufacturer, count the number of drops 
corresponding to the distilled/deionized water liquid volume between 
the upper and lower etched marks on the stalagmometer. If the number 
of drops for the distilled/deionized water is not within 1 drop of the number indicated on the instrument, the 
stalagmometer must be cleaned, using the procedures specified in 
Sections 11.1.4.1 through 11.1.4.10 of this method, before using the 
instrument to measure the surface tension of the tank liquid.
    11.1.2.2.1 If the stalagmometer must be cleaned, as indicated in 
Section 11.1.2.2, repeat the procedure specified in Section 11.1.2.2 
before proceeding.
    11.1.2.2.2 If, after cleaning and performing the procedure in 
Section 11.1.2.2, the number of drops indicated for the distilled/
deionized water is not within 1 drop of the number 
indicated on the instrument, either use the number of drops 
corresponding to the distilled/deionized water volume as the 
reference number of drops, or replace the instrument.
    11.1.3 Determine the surface tension of the tank liquid using 
the procedures specified by the manufacturer of the stalagmometer.
    11.1.4 Stalagmometer cleaning procedures. The procedures 
specified in Sections 11.1.4.1 through 11.1.4.10 shall be used for 
cleaning a stalagmometer, as required by Section 11.1.2.2.
    11.1.4.1 Set up the stalagmometer on its stand in a fume hood.
    11.1.4.2 Place a clean 150 (mL) beaker underneath the 
stalagmometer and fill the beaker with reagent grade concentrated 
nitric acid.
    11.1.4.3 Immerse the bottom tip of the stalagmometer 
(approximately 1 centimeter (0.5 inches)) into the beaker.
    11.1.4.4 Squeeze the rubber bulb and pinch at the arrow up (1) 
position to collapse.
    11.1.4.5 Place the bulb end securely on top end of stalagmometer 
and carefully draw the nitric acid by pinching the arrow up (1) 
position until the level is above the top etched line.
    11.1.4.6 Allow the nitric acid to remain in stalagmometer for 5 
minutes, then

[[Page 65149]]

carefully remove the bulb, allowing the acid to completely drain.
    11.1.4.7 Fill a clean 150 mL beaker with distilled or deionized 
water.
    11.1.4.8 Using the rubber bulb per the instructions in Sections 
11.1.4.4 and 11.1.4.5, rinse and drain stalagmometer with deionized 
or distilled water.
    11.1.4.9 Fill a clean 150 mL beaker with isopropyl alcohol.
    11.1.4.10 Again using the rubber bulb per the instructions in 
Sections 11.1.4.4 and 11.1.4.5, rinse and drain stalagmometer twice 
with isopropyl alcohol and allow the stalagmometer to dry 
completely.
* * * * *
    11.2.2 If a measurement of the surface tension of the solution 
is above the 45 dynes per centimeter limit when measured using a 
stalagmometer, above 35 dynes per centimeter when measured using a 
tensiometer, or above an alternate surface tension limit established 
during the performance test, the time interval shall revert back to 
the original monitoring schedule of once every 4 hours. A subsequent 
decrease in frequency would then be allowed according to Section 
11.2.1.
* * * * *
[FR Doc. 2010-23839 Filed 10-20-10; 8:45 am]
BILLING CODE 6560-50-P