Document ID: EPA-HQ-OAR-2014-0741-0001
Agency: epa
Document Type: Proposed Rule
Title: National Emission Standards: Hazardous Air Pollutants for Chemical Recovery Combustion Sources at Kraft, Soda, Sulfite, and Stand-Alone Semichemical Pulp Mills
Posted Date: 2016-12-30T05:00Z

[Federal Register Volume 81, Number 251 (Friday, December 30, 2016)]
[Proposed Rules]
[Pages 97046-97095]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2016-30758]

[[Page 97045]]

Vol. 81

Friday,

No. 251

December 30, 2016

Part V

 Environmental Protection Agency

-----------------------------------------------------------------------

40 CFR Part 63

National Emission Standards for Hazardous Air Pollutants for Chemical 
Recovery Combustion Sources at Kraft, Soda, Sulfite, and Stand-Alone 
Semichemical Pulp Mills; Proposed Rule

  Federal Register / Vol. 81 , No. 251 / Friday, December 30, 2016 / 
Proposed Rules  

[[Page 97046]]

-----------------------------------------------------------------------

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 63

[EPA-HQ-OAR-2014-0741; FRL-9957-07-OAR]
RIN 2060-AS46

National Emission Standards for Hazardous Air Pollutants for 
Chemical Recovery Combustion Sources at Kraft, Soda, Sulfite, and 
Stand-Alone Semichemical Pulp Mills

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

-----------------------------------------------------------------------

SUMMARY: The Environmental Protection Agency (EPA) is proposing 
amendments to the National Emission Standards for Hazardous Air 
Pollutants (NESHAP) for Chemical Recovery Combustion Sources at Kraft, 
Soda, Sulfite, and Stand-Alone Semichemical Pulp Mills to address the 
results of the residual risk and technology review (RTR) that the EPA 
is required to conduct under the Clean Air Act (CAA). These proposed 
amendments include revisions to the opacity monitoring provisions; 
addition of electrostatic precipitator (ESP) parameter monitoring 
provisions; a requirement for 5-year periodic emissions testing; 
revisions to provisions addressing periods of startup, shutdown, and 
malfunction (SSM); and technical and editorial changes. The EPA is 
proposing these amendments to improve the effectiveness of the rule.

DATES: Comments. Comments must be received on or before February 28, 
2017. Under the Paperwork Reduction Act (PRA), comments on the 
information collection provisions are best assured of consideration if 
the Office of Management and Budget (OMB) receives a copy of your 
comments on or before January 30, 2017.
    Public Hearing. A public hearing will be held if requested by 
January 4, 2017.

ADDRESSES: Comments. Submit your comments, identified by Docket ID No. 
EPA-HQ-OAR-2014-0741, at http://www.regulations.gov. Follow the online 
instructions for submitting comments. Once submitted, comments cannot 
be edited or removed from Regulations.gov. The EPA may publish any 
comment received to its public docket. Do not submit electronically any 
information you consider to be Confidential Business Information (CBI) 
or other information whose disclosure is restricted by statute. 
Multimedia submissions (audio, video, etc.) must be accompanied by a 
written comment. The written comment is considered the official comment 
and should include discussion of all points you wish to make. The EPA 
will generally not consider comments or comment contents located 
outside of the primary submission (i.e., on the Web, cloud, or other 
file sharing system). For additional submission methods, the full EPA 
public comment policy, information about CBI or multimedia submissions, 
and general guidance on making effective comments, please visit http://www2.epa.gov/dockets/commenting-epa-dockets.
    Instructions. Direct your comments to Docket ID No. EPA-HQ-OAR-
2014-0741. The EPA's policy is that all comments received will be 
included in the public docket without change and may be made available 
online at http://www.regulations.gov, including any personal 
information provided, unless the comment includes information claimed 
to be 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 email. The 
http://www.regulations.gov Web site is an ``anonymous access'' system, 
which means the EPA will not know your identity or contact information 
unless you provide it in the body of your comment. If you send an email 
comment directly to the EPA without going through http://www.regulations.gov, your email address will be automatically captured 
and included as part of the comment that is placed in the public docket 
and made available on the Internet. If you submit an electronic 
comment, the EPA recommends that you include your name and other 
contact information in the body of your comment and with any disk or 
CD-ROM you submit. If the EPA cannot read your comment due to technical 
difficulties and cannot contact you for clarification, the EPA may not 
be able to consider your comment. Electronic files should not include 
special characters or any form of encryption and be free of any defects 
or viruses. For additional information about the EPA's public docket, 
visit the EPA Docket Center homepage at http://www.epa.gov/dockets.
    Docket. The EPA has established a docket for this rulemaking under 
Docket ID No. EPA-HQ-OAR-2014-0741. All documents in the docket are 
listed in the 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 Regulations.gov or in 
hard copy at the EPA Docket Center, Room 3334, EPA WJC West Building, 
1301 Constitution Ave. NW., Washington, DC. The Public Reading Room is 
open from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding 
legal holidays. The telephone number for the Public Reading Room is 
(202) 566-1744, and the telephone number for the EPA Docket Center is 
(202) 566-1742.
    Public Hearing. A public hearing will be held, if requested by 
January 4, 2017, to accept oral comments on this proposed action. If a 
hearing is requested, it will be held at the EPA's Washington, DC 
campus located at 1201 Constitution Avenue NW., Washington, DC. The 
hearing, if requested, will begin at 9:00 a.m. (local time) and will 
conclude at 5:00 p.m. (local time) on January 17, 2017. To request a 
hearing, to register to speak at a hearing, or to inquire if a hearing 
will be held, please contact Ms. Aimee St. Clair at (919) 541-1063 or 
by email at stclair.aimee@epa.gov. The last day to pre-register to 
speak at a hearing, if one is held, will be January 12, 2017.
    Additionally, requests to speak will be taken the day of the 
hearing at the hearing registration desk, although preferences on 
speaking times may not be able to be fulfilled. Please note that 
registration requests received before the hearing will be confirmed by 
the EPA via email. The EPA will make every effort to accommodate all 
speakers who arrive and register. Because the hearing will be held at a 
United States governmental facility, individuals planning to attend the 
hearing should be prepared to show valid picture identification to the 
security staff in order to gain access to the meeting room. Please note 
that the REAL ID Act, passed by Congress in 2005, established new 
requirements for entering federal facilities. If your driver's license 
is issued by Alaska, American Samoa, Arizona, Kentucky, Louisiana, 
Maine, Massachusetts, Minnesota, Montana, New York, Oklahoma or the 
state of Washington, you must present an additional form of 
identification to enter the federal building. Acceptable alternative 
forms of identification include: Federal employee badges, passports, 
enhanced driver's licenses and military identification cards. In 
addition, you will need to obtain a property pass for any personal 
belongings you bring with you. Upon leaving the building, you will be 
required to return this property pass to

[[Page 97047]]

the security desk. No large signs will be allowed in the building, 
cameras may only be used outside of the building and demonstrations 
will not be allowed on federal property for security reasons.
    Please note that any updates made to any aspect of the hearing, 
including whether or not a hearing will be held, will be posted online 
at https://www.epa.gov/stationary-sources-air-pollution/kraft-soda-sulfite-and-stand-alone-semichemical-pulp-mills-mact-ii. We ask that 
you contact Ms. Aimee St. Clair at (919) 541-1063 or by email at 
stclair.aimee@epa.gov or monitor our Web site to determine if a hearing 
will be held. The EPA does not intend to publish a notice in the 
Federal Register announcing any such updates. Please go to https://www.epa.gov/stationary-sources-air-pollution/kraft-soda-sulfite-and-stand-alone-semichemical-pulp-mills-mact-ii for more information on the 
public hearing.

FOR FURTHER INFORMATION CONTACT: For questions about this proposed 
action, contact Dr. Kelley Spence, Sector Policies and Programs 
Division (Mail Code: E143-03), Office of Air Quality Planning and 
Standards, U.S. Environmental Protection Agency, Research Triangle 
Park, North Carolina 27711; telephone number: (919) 541-3158; fax 
number: (919) 541-3470; and email address: spence.kelley@epa.gov. For 
specific information regarding the risk modeling methodology, contact 
Mr. James Hirtz, Health and Environmental Impacts Division (Mail Code: 
C539-02), Office of Air Quality Planning and Standards, U.S. 
Environmental Protection Agency, Research Triangle Park, North Carolina 
27711; telephone number: (919) 541-0881; fax number: (919) 541-0840; 
and email address: hirtz.james@epa.gov. For information about the 
applicability of the NESHAP to a particular entity, contact Ms. Sara 
Ayres, Office of Enforcement and Compliance Assurance, U.S. 
Environmental Protection Agency, USEPA Region 5 (Mail Code: E-19J), 77 
West Jackson Boulevard, Chicago IL 60604; telephone number: (312) 353-
6266; and email address: ayres.sara@epa.gov.

SUPPLEMENTARY INFORMATION: 
    Preamble Acronyms and Abbreviations. We use multiple acronyms and 
terms in this preamble. While this list may not be exhaustive, to ease 
the reading of this preamble and for reference purposes, the EPA 
defines the following terms and acronyms here:

AEGL acute exposure guideline levels
AERMOD air dispersion model used by the HEM-3 model
ANSI American National Standards Institute
ASME American Society of Mechanical Engineers
ASTM American Society for Testing and Materials
ATSDR Agency for Toxic Substances and Disease Registry
BACT best available control technology
BAT best available technology
BLO black liquor oxidation
BLS black liquor solids
CAA Clean Air Act
CaCO3 calcium carbonate
CalEPA California EPA
CBI Confidential Business Information
CEDRI Compliance and Emissions Data Reporting Interface
CFR Code of Federal Regulations
CMS continuous monitoring system
COMS continuous opacity monitoring system
CPMS continuous parameter monitoring system
DCE direct contact evaporator
EJ environmental justice
EPA Environmental Protection Agency
ERPG Emergency Response Planning Guidelines
ERT Electronic Reporting Tool
ESP electrostatic precipitator
FR Federal Register
gr/dscf grains per dry standard cubic foot
HAP hazardous air pollutant
HCCPD hexachlorocyclopentadiene
HCl hydrochloric acid
HEM-3 Human Exposure Model, Version 1.1.0
HF hydrogen fluoride
HI hazard index
HQ hazard quotient
IBR incorporation by reference
ICR Information Collection Request
IRIS Integrated Risk Information System
km kilometer
LAER lowest achievable emission rate
lb/hr pounds per hour
lb/ton pounds per ton
LOAEL lowest-observed-adverse-effect level
MACT maximum achievable control technology
mg/kg-day milligrams per kilogram per day
mg/m\3\ milligrams per cubic meter
MIR maximum individual risk
Na2CO3 sodium carbonate
Na2S sodium sulfide
NAAQS National Ambient Air Quality Standards
NAC National Advisory Committee
NAICS North American Industry Classification System
NaOH sodium hydroxide
NAS National Academy of Sciences
NATA National Air Toxics Assessment
NCASI National Council for Air and Stream Improvement
NDCE nondirect contact evaporator
NEI National Emissions Inventory
NESHAP National Emission Standards for Hazardous Air Pollutants
NH3 ammonia
NOAA National Oceanic and Atmospheric Administration
NOAEL no-observed-adverse-effect level
NRC National Research Council
NRDC Natural Resources Defense Council
NSPS New Source Performance Standards
NTTAA National Technology Transfer and Advancement Act
O&M operation and maintenance
O2 oxygen
OAQPS Office of Air Quality Planning and Standards
OMB Office of Management and Budget
PAH polycyclic aromatic hydrocarbons
PB-HAP hazardous air pollutant known to be persistent and bio-
accumulative in the environment
PDF portable document format
PEL probable effects level
PM particulate matter
PM2.5 fine particles (particulate matter with particles 
less than 2.5 micrometers in diameter)
POM polycyclic organic matter
ppm parts per million
PRA Paperwork Reduction Act
PTC Performance Test Code
QA quality assurance
RACT reasonably available control technology
RBLC RACT/BACT/LAER Clearinghouse
REL reference exposure level
RFA Regulatory Flexibility Act
RfC reference concentration
RfD reference dose
RTO regenerative thermal oxidizer
RTR residual risk and technology review
SAB Science Advisory Board
SCC source classification code
SDT smelt dissolving tank
SOP standard operating procedure
SSM startup, shutdown, and malfunction
STAPPA/ State and Territorial Air Pollution Program
ALAPCO Administrators/Association of Local Air Pollution Control 
Officers
TEQ toxic equivalent
THC total hydrocarbon
TOSHI target organ-specific hazard index
tpy tons per year
TRIM.FaTE Total Risk Integrated Methodology.Fate, Transport, and 
Ecological Exposure model
TRS total reduced sulfur
UF uncertainty factor
[mu]g/m3 micrograms per cubic meter
UMRA Unfunded Mandates Reform Act
URE unit risk estimate
yr year

    Organization of this Document. The information in this preamble is 
organized as follows:

I. General Information
    A. Executive Summary
    B. Does this action apply to me?
    C. Where can I get a copy of this document and other related 
information?
    D. What should I consider as I prepare my comments for the EPA?
II. Background
    A. What is the statutory authority for this action?
    B. What is this source category and how does the current NESHAP 
regulate its HAP emissions?
    C. What data collection activities were conducted to support 
this action?
    D. What other relevant background information and data are 
available?
III. Analytical Procedures

[[Page 97048]]

    A. How did we estimate post-MACT risks posed by the source 
category?
    B. How did we consider the risk results in making decisions for 
this proposal?
    C. How did we perform the technology review?
IV. Analytical Results and Proposed Decisions
    A. What are the results of the risk assessment and analyses?
    B. What are our proposed decisions regarding risk acceptability, 
ample margin of safety, and adverse environmental effects?
    C. What are the results and proposed decisions based on our 
technology review?
    D. What other actions are we proposing?
    E. What compliance dates are we proposing?
V. Summary of Cost, Environmental, and Economic Impacts
    A. What are the affected sources?
    B. What are the air quality impacts?
    C. What are the cost impacts?
    D. What are the economic impacts?
    E. What are the benefits?
VI. Request for Comments
VII. Submitting Data Corrections
VIII. Statutory and Executive Order Reviews
    A. Executive Order 12866: Regulatory Planning and Review and 
Executive Order 13563: Improving Regulation and Regulatory Review
    B. Paperwork Reduction Act (PRA)
    C. Regulatory Flexibility Act (RFA)
    D. Unfunded Mandates Reform Act (UMRA)
    E. Executive Order 13132: Federalism
    F. Executive Order 13175: Consultation and Coordination with 
Indian Tribal Governments
    G. Executive Order 13045: Protection of Children from 
Environmental Health Risks and Safety Risks
    H. Executive Order 13211: Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution, or Use
    I. National Technology Transfer and Advancement Act (NTTAA) and 
1 CFR part 51
    J. Executive Order 12898: Federal Actions to Address 
Environmental Justice in Minority Populations and Low-Income 
Populations

I. General Information

A. Executive Summary

1. Purpose of the Regulatory Action
    Section 112(f)(2) of the CAA requires the EPA to analyze and 
address the residual risk associated with hazardous air pollutant 
emissions from source categories subject to maximum achievable control 
technology (MACT) standards. This review, known as the residual risk 
review, is a one-time review that the statute provides will be done 
within 8 years of issuance of the MACT standard. Section 112(d)(6) of 
the CAA requires the EPA to review and revise CAA section 112 emissions 
standards, as necessary, taking into account developments in practices, 
processes, and control technologies. Emission standards promulgated 
under CAA section 112 are to be reviewed no less often than every 8 
years. The EPA issued the NESHAP for Chemical Recovery Combustion 
Sources at Kraft, Soda, Sulfite, and Stand-Alone Semichemical Mills (40 
Code of Federal Regulations (CFR) part 63, subpart MM) in 2001. The 
2001 emission standards are due for review under CAA sections 112(d)(6) 
and 112(f)(2). In addition to conducting the RTR for subpart MM, we are 
evaluating the SSM provisions in the rule in light of the United States 
Court of Appeals for the District of Columbia Circuit decision in 
Sierra Club v. EPA, 551 F.3d 1019 (D.C. Cir. 2008). As explained in 
section IV of this preamble, in the Sierra Club case, the D.C. Circuit 
vacated the SSM exemption provisions in the General Provisions for 
nonopacity and opacity standards. Finally, the EPA evaluated the rule 
to determine if additional amendments were warranted or necessary to 
ensure continuous compliance with the standard and to promote 
consistency with other standards.
2. Summary of the Major Proposed Revisions
    The EPA is not proposing to make any changes pursuant to 112(f)(2) 
as a result of its residual risk review. The EPA is proposing to reduce 
opacity limits as a result of the technology review under CAA section 
112(d)(6). In addition, we are proposing the following as part of the 
technology review: Revising the opacity monitoring provisions, 
requiring ESP parameter monitoring for processes equipped with ESPs, 
clarifying the monitoring for combined ESP/wet scrubber controls, and 
providing alternative monitoring for smelt dissolving tank (SDT) wet 
scrubbers.
    As an additional action, we are proposing to improve the compliance 
provisions of the subpart by proposing to require periodic air 
emissions performance testing once every 5 years for facilities subject 
to the standards for Chemical Recovery Combustion Sources at Kraft, 
Soda, Sulfite, and Stand-Alone Semichemical Pulp Mills. To address the 
SSM exemptions, we are proposing amendments to subpart MM that will (1) 
require facilities to meet the standard at all times, including during 
periods of SSM, and (2) provide alternative monitoring parameters for 
wet scrubbers and ESPs during these periods. We are also proposing 
changes to the subpart MM NESHAP and the General Provisions 
applicability table to eliminate the SSM exemption. To increase the 
ease and efficiency of data submittal and improve data accessibility, 
we are proposing to require mills to submit electronic copies of 
compliance reports, which includes performance test reports.
    We are also proposing a number of technical and editorial changes. 
These changes include the following: Clarifying the location in 40 CFR 
part 60 of applicable EPA test methods; updating the facility name for 
Cosmo Specialty Fibers; revising the definitions section in 40 CFR 
63.861; corrected misspelling in 40 CFR 63.862(c), revising multiple 
sections to remove reference to former smelters and former black liquor 
gasification system at Georgia-Pacific's facility in Big Island, 
Virginia; revising the monitoring requirements section; revising the 
performance test requirements section to specify the conditions for 
conducting performance tests and to revise the ambient O2 concentration 
in Equations 7 and 8; revising the recordkeeping requirements section 
in 40 CFR 63.866 to include the requirement to record information on 
failures to meet the applicable standard; revising the terminology in 
the delegation of authority section in 40 CFR 63.868 to match the 
definitions in 40 CFR 63.90; and revising the General Provisions 
applicability table (Table 1 to subpart MM of part 63) to align with 
those sections of the General Provisions that have been amended or 
reserved over time.
3. Costs and Benefits
    Table 1 summarizes the costs of this action. See section V of this 
preamble for further discussion.

          Table 1--Summary of the Costs of This Proposed Action
------------------------------------------------------------------------
                                           Capital cost,  Annual cost, $
               Requirement                   $ million        million
------------------------------------------------------------------------
Change in opacity monitoring provisions               42             8.8
 for recovery furnaces and lime kilns...
ESP parameter monitoring................             5.7             1.4

[[Page 97049]]

 
Periodic emissions testing..............  ..............             1.1
Incremental reporting/recordkeeping.....            0.50             1.9
                                         -------------------------------
    Total nationwide....................              48              13
------------------------------------------------------------------------

    The EPA estimates that the proposed changes to the opacity limits 
and monitoring allowances will reduce PM emissions by approximately 235 
(tons per year) tpy and fine particle (PM2.5) emissions by 
approximately 112 tpy. Periodic testing will tend to reduce emissions 
by providing incentive for facilities to maintain their control systems 
and make periodic adjustments to ensure peak performance. Eliminating 
the SSM exemption will reduce emissions by requiring facilities to meet 
the applicable standard during SSM periods. See section V of this 
preamble for further discussion.

B. Does this action apply to me?

    Table 2 of this preamble lists the NESHAP and associated regulated 
industrial source categories that are the subject of this proposal. 
Table 2 is not intended to be exhaustive, but rather provides a guide 
for readers regarding the entities that this proposed action is likely 
to affect. The proposed standards, once promulgated, will be directly 
applicable to the affected sources. Federal, state, local, and tribal 
government entities would not be affected by this proposed action. As 
defined in the Initial List of Categories of Sources Under Section 
112(c)(1) of the Clean Air Act Amendments of 1990 (see 57 FR 31576, 
July 16, 1992), the ``Pulp and Paper Production'' source category is 
any facility engaged in the production of pulp and/or paper. The EPA 
developed the NESHAPs for the source category in phases. This NESHAP, 
40 CFR part 63, subpart MM, regulates chemical recovery combustion 
sources at kraft, soda, sulfite, and stand-alone semichemical pulp 
mills. The NESHAP for non-combustion sources (40 CFR part 63, subpart 
S) regulates non-combustion processes at mills that (1) chemically pulp 
wood fiber (using kraft, sulfite, soda, and semichemical methods), (2) 
mechanically pulp wood fiber (e.g., groundwood, thermomechanical, 
pressurized), (3) pulp secondary fibers (deinked and non-deinked), (4) 
pulp non-wood material, and (5) manufacture paper. This proposal only 
addresses the RTR for subpart MM, and does not propose any amendments 
to subpart S.

                Table 2--NESHAP and Industrial Source Categories Affected by This Proposed Action
----------------------------------------------------------------------------------------------------------------
                Source category                                  NESHAP                       NAICS code \a\
----------------------------------------------------------------------------------------------------------------
Pulp and Paper Production......................  Chemical Recovery Combustion Sources        32211, 32212, 32213
                                                  at Kraft, Soda, Sulfite, and Stand-
                                                  Alone Semichemical Pulp Mills.
----------------------------------------------------------------------------------------------------------------
\a\ North American Industry Classification System.

C. 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 action is available on the Internet through the EPA's Stationary 
Sources of Air Pollution Web site, a forum for information and 
technology exchange in various areas of air pollution control. A 
redline version of the regulatory language that incorporates the 
proposed changes in this action is available in the docket for this 
action (Docket ID No. EPA-HQ-OAR-2014-0741). Following signature by the 
EPA Administrator, the EPA will post a copy of this proposed action at: 
https://www.epa.gov/stationary-sources-air-pollution/kraft-soda-sulfite-and-stand-alone-semichemical-pulp-mills-mact-ii. Following 
publication in the Federal Register, the EPA will post the Federal 
Register version of the proposal and key technical documents at this 
same Web site. Information on the overall RTR program is available at 
http://www3.epa.gov/ttn/atw/rrisk/rtrpg.html.

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

    Submitting CBI. Do not submit information containing CBI to the EPA 
through http://www.regulations.gov or email. 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 the EPA, mark the outside of the disk 
or CD-ROM as CBI and then identify electronically within the disk or 
CD-ROM the specific information that is claimed as CBI. In addition to 
one complete version of the comments that includes information claimed 
as CBI, you must submit a copy of the comments that does not contain 
the information claimed as CBI 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 the 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: OAQPS Document Control Officer (C404-
02), OAQPS, U.S. Environmental Protection Agency, Research Triangle 
Park, North Carolina 27711, Attention Docket ID No. EPA-HQ-OAR-2014-
0741.

II. Background

A. What is the statutory authority for this action?

    Section 112 of the CAA establishes a two-stage regulatory process 
to address emissions of hazardous air pollutants (HAPs) from stationary 
sources. In the first stage, after the EPA has identified categories of 
sources emitting one or more of the HAPs listed in CAA section 112(b), 
CAA section 112(d) requires the Agency to promulgate technology-based 
NESHAPs for those sources. ``Major sources'' are those that emit or 
have the potential to emit 10 tpy or more of a single HAP or 25 tpy or 
more of any combination of HAPs. For major sources, the technology-
based NESHAP must reflect the maximum degree of

[[Page 97050]]

emission reductions of HAPs achievable (after considering cost, energy 
requirements, and non-air quality health and environmental impacts) and 
are commonly referred to as MACT standards.
    MACT standards must reflect the maximum degree of emissions 
reduction achievable through the application of measures, processes, 
methods, systems, or techniques, including, but not limited to, 
measures that: (1) Reduce the volume of or eliminate pollutants through 
process changes, substitution of materials, or other modifications; (2) 
enclose systems or processes to eliminate emissions; (3) capture or 
treat pollutants when released from a process, stack, storage, or 
fugitive emissions point; (4) are design, equipment, work practice, or 
operational standards (including requirements for operator training or 
certification); or (5) are a combination of the above. CAA section 
112(d)(2)(A)-(E). The MACT standards may take the form of design, 
equipment, work practice, or operational standards where the EPA first 
determines either that: (1) 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 (2) the application of measurement 
methodology to a particular class of sources is not practicable due to 
technological and economic limitations. CAA section 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 emissions control that is achieved in practice by 
the best-controlled similar source. The MACT floor for existing sources 
can be less stringent than floors for new sources, but not less 
stringent than the average emissions 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, the EPA must also consider control options that are more 
stringent than the floor. We may establish standards more stringent 
than the floor based on considerations of the cost of achieving the 
emission reductions, any non-air quality health and environmental 
impacts, and energy requirements.
    The EPA is then required to review these technology-based standards 
and revise them ``as necessary (taking into account developments in 
practices, processes, and control technologies)'' no less frequently 
than every 8 years. CAA section 112(d)(6). In conducting this review, 
the EPA is not required to recalculate the MACT floor. Natural 
Resources Defense Council (NRDC) v. EPA, 529 F.3d 1077, 1084 (D.C. Cir. 
2008). Association of Battery Recyclers, Inc. v. EPA, 716 F.3d 667 
(D.C. Cir. 2013).
    The second stage in standard-setting focuses on reducing any 
remaining (i.e., ``residual'') risk according to CAA section 112(f). 
Section 112(f)(1) of the CAA required that the EPA prepare a report to 
Congress discussing (among other things) methods of calculating the 
risks posed (or potentially posed) by sources after implementation of 
the MACT standards, the public health significance of those risks, and 
the EPA's recommendations as to legislation regarding such remaining 
risk. The EPA prepared and submitted the Residual Risk Report to 
Congress, EPA-453/R-99-001 (Risk Report) in March 1999. Section 
112(f)(2) of the CAA then provides that if Congress does not act on any 
recommendation in the Risk Report, the EPA must analyze and address 
residual risk for each category or subcategory of sources 8 years after 
promulgation of such standards pursuant to CAA section 112(d).
    Section 112(f)(2) of the CAA requires the EPA to determine for 
source categories subject to MACT standards whether promulgation of 
additional standards is needed to provide an ample margin of safety to 
protect public health. Section 112(f)(2)(B) of the CAA expressly 
preserves the EPA's use of the two-step process for developing 
standards to address any residual risk and the Agency's interpretation 
of ``ample margin of safety'' developed in the National Emissions 
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 EPA notified Congress in 
the Risk Report that the Agency intended to use the Benzene NESHAP 
approach in making CAA section 112(f) residual risk determinations 
(EPA-453/R-99-001, p. ES-11). The EPA subsequently adopted this 
approach in its residual risk determinations and, in a challenge to the 
risk review for the Synthetic Organic Chemical Manufacturing source 
category, the United States Court of Appeals for the District of 
Columbia Circuit upheld as reasonable the EPA's interpretation that CAA 
section 112(f)(2) incorporates the approach established in the Benzene 
NESHAP. See NRDC v. EPA, 529 F.3d 1077, 1083 (D.C. Cir. 2008) 
(``[S]ubsection 112(f)(2)(B) expressly incorporates the EPA's 
interpretation of the Clean Air Act from the Benzene standard, complete 
with a citation to the Federal Register.''); see also, A Legislative 
History of the Clean Air Act Amendments of 1990, vol. 1, p. 877 (Senate 
debate on Conference Report).
    The first step in the process of evaluating residual risk is the 
determination of acceptable risk. If risks are unacceptable, the EPA 
cannot consider cost in identifying the emissions standards necessary 
to bring risks to an acceptable level. The second step is the 
determination of whether standards must be further revised in order to 
provide an ample margin of safety to protect public health. The ample 
margin of safety is the level at which the standards must be set, 
unless an even more stringent standard is necessary to prevent, taking 
into consideration costs, energy, safety, and other relevant factors, 
an adverse environmental effect.
1. Step 1--Determination of Acceptability
    The Agency in the Benzene NESHAP concluded that ``the acceptability 
of risk under section 112 is best judged on the basis of a broad set of 
health risk measures and information'' and that the ``judgment on 
acceptability cannot be reduced to any single factor.'' Benzene NESHAP 
at 38046. 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'' (Risk Report at 178, quoting NRDC v. EPA, 824 F. 2d 
1146, 1165 (D.C. Cir. 1987) (en banc) (``Vinyl Chloride''), 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 one in 10 thousand, that risk level is considered 
acceptable.'' 54 FR at 38045, September 14, 1989. We discussed the 
maximum individual lifetime cancer risk (or maximum individual risk 
(MIR)) 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

[[Page 97051]]

acknowledged 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 
the MIR as a metric for determining acceptability, we acknowledged in 
the 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. Further, in the 
Benzene NESHAP, we noted that:

    ``[p]articular attention will also be accorded to the weight of 
evidence presented in the risk assessment of potential 
carcinogenicity or other health effects of a pollutant. While the 
same numerical risk may be estimated for an exposure to a pollutant 
judged to be a known human carcinogen, and to a pollutant considered 
a possible human carcinogen based on limited animal test data, the 
same weight cannot be accorded to both estimates. In considering the 
potential public health effects of the two pollutants, the Agency's 
judgment on acceptability, including the MIR, will be influenced by 
the greater weight of evidence for the known human carcinogen.''

    Id. at 38046. The Agency also explained in the Benzene NESHAP that:

    ``[i]n establishing a presumption for MIR, 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 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. at 38045. 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 noted earlier, in NRDC v. EPA, the court held that CAA section 
112(f)(2) ``incorporates the EPA's interpretation of the Clean Air Act 
from the Benzene Standard.'' The court further held that Congress' 
incorporation of the Benzene standard applies equally to carcinogens 
and non-carcinogens. 529 F.3d at 1081-82. Accordingly, we also consider 
non-cancer risk metrics in our determination of risk acceptability and 
ample margin of safety.
2. Step 2--Determination of Ample Margin of Safety
    Section 112(f)(2) of the CAA requires the EPA to determine, for 
source categories subject to MACT standards, whether those standards 
provide an ample margin of safety to protect public health. As 
explained in the Benzene NESHAP, ``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 . . . . 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 section 112.'' 54 FR at 38046, September 14, 1989.
    According to CAA section 112(f)(2)(A), 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 
one in one million,'' the 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, the EPA 
may adopt standards equal to existing MACT standards if the EPA 
determines that the existing standards (i.e., the MACT standards) are 
sufficiently protective. NRDC v. EPA, 529 F.3d 1077, 1083 (D.C. Cir. 
2008) (``If EPA determines that the existing technology-based standards 
provide an `ample margin of safety,' then the Agency is free to readopt 
those standards during the residual risk rulemaking.'') The 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 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. CAA section 112(a)(7).
---------------------------------------------------------------------------

    The CAA does not specifically define the terms ``individual most 
exposed,'' ``acceptable level,'' and ``ample margin of safety.'' In the 
Benzene NESHAP, 54 FR at 38044-38045, September 14, 1989, the Agency 
stated as an overall objective:

    In protecting public health with an ample margin of safety under 
section 112, EPA strives 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 
plant would have if he or she were exposed to the maximum pollutant 
concentrations for 70 years.

    The Agency further stated that ``[t]he 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 risks 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.'' Id. at 38045.
    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, including the incremental risk reduction 
associated with standards more stringent than the MACT standard or a 
more stringent standard that the EPA has determined is necessary to 
ensure risk is acceptable. In the ample margin of safety analysis, the 
Agency considers additional factors, 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, September 14, 1989.

B. What is this source category and how does the current NESHAP 
regulate its HAP emissions?

    The ``Pulp and Paper Production'' source category includes any 
facility engaged in the production of pulp and/or paper. The EPA 
developed the NESHAPs for the source category in two phases. The first 
phase, 40 CFR part 63, subpart S, regulates pulping and paper 
production processes, and was

[[Page 97052]]

originally promulgated in 1998. The second phase, 40 CFR part 63, 
subpart MM, regulates chemical recovery combustion sources at kraft, 
soda, sulfite, and stand-alone semichemical pulp mills, and was 
originally promulgated in 2001. Another separate NESHAP, 40 CFR part 
63, subpart DDDDD, covers other combustion sources located at pulp 
mills, such as industrial boilers. This proposal focuses exclusively on 
the RTR for subpart MM. The EPA is not proposing any amendments to 
Subpart DDDDD or subpart S in this notice.
    Subpart MM of 40 CFR part 63 was promulgated on January 12, 2001 
(66 FR 3180). As promulgated in 2001, the subpart MM MACT standard 
applies to major sources of HAP emissions from chemical recovery 
combustion sources at kraft, soda, sulfite, and stand-alone 
semichemical pulp mills. The chemical recovery combustion sources 
include kraft and soda recovery furnaces, SDTs, and lime kilns; kraft 
black liquor oxidation (BLO) units; sulfite combustion units; and 
semichemical combustion units. Subpart S was promulgated on April 15, 
1998 (63 FR 18504), and underwent a RTR, with final amendments to 
subpart S promulgated on September 11, 2012 (77 FR 55698).
    This proposal includes both a risk assessment and a technology 
review of the emission sources in 40 CFR part 63, subpart MM, as well 
as a risk assessment of the whole facility. The whole facility risk 
assessment includes emissions from all sources of HAP at the facility, 
including sources covered by other NESHAP (e.g., boilers covered under 
40 CFR part 63, subpart DDDDD; pulp and paper production processes 
covered under 40 CFR part 63, subpart S; paper coating operations 
covered under 40 CFR part 63, subpart JJJJ).
    According to results of the EPA's 2011 pulp and paper information 
collection request (ICR), and updates based on more recent information, 
there are a total of 108 major sources in the United States that 
conduct chemical recovery combustion operations, including 97 kraft 
pulp mills, 1 soda pulp mill, 3 sulfite pulp mills, and 7 stand-alone 
semichemical pulp mills.
    Subpart MM of 40 CFR part 63 includes numerical emission limits for 
recovery furnaces, SDTs, lime kilns, and sulfite and semichemical 
combustion units. The control systems used by most mills to meet the 
subpart MM emission limits are as follows:
     Recovery furnaces: ESPs, wet scrubbers, and nondirect 
contact evaporator (NDCE) furnace design with dry-bottom ESP, and dry 
particulate matter (PM) return system.
     Smelt dissolving tanks: Wet scrubbers, mist eliminators, 
and venting to recovery furnace.
     Lime kilns: ESPs and wet scrubbers.
     Sulfite combustion units: Wet scrubbers and mist 
eliminators.
     Semichemical combustion units: Wet scrubbers, ESPs, and 
regenerative thermal oxidizers (RTOs).

C. What data collection activities were conducted to support this 
action?

    In February 2011, the EPA issued an ICR, pursuant to CAA section 
114, to United States pulp and paper manufacturers to gather 
information needed to conduct the regulatory reviews required under CAA 
sections 112(d)(6) and (f)(2). The EPA divided the ICR into three 
parts. Part I requested available information regarding 40 CFR part 63, 
subpart S process equipment, control devices, pulp and paper 
production, bleaching, and other aspects of facility operations to 
support the subpart S technology review and the review of the Kraft 
Pulp Mills New Source Performance Standards (NSPS) under 40 CFR part 
60, subpart BB. Part II requested updated inventory data for all pulp 
and paper emission sources to support the residual risk assessment for 
the pulp and paper sector (including 40 CFR part 63, subparts S and MM) 
and to supplement the National Emissions Inventory (NEI) for the source 
category for purposes of detailed residual risk modeling. Part III 
requested available information on subpart MM chemical recovery 
combustion equipment, control devices, and other pertinent information, 
to support the subpart MM technology review and the subpart BB NSPS 
review. The response rate for the ICR was 100 percent.

D. What other relevant background information and data are available?

    In addition to ICR responses, the EPA reviewed a number of other 
information sources to determine if there have been developments in 
practices, processes, or control technologies by chemical recovery 
combustion sources. These include:
     Permit limits from permits submitted with ICR responses 
and collected from state agencies.
     Information on air pollution control options in the pulp 
and paper industry from the RACT/BACT/LAER Clearinghouse (RBLC).
     Information on best available techniques in the pulp and 
paper industry from a 2015 European Commission document, titled Best 
Available Techniques (BAT) Reference Document for the Production of 
Pulp, Paper and Board.
     Information on the most effective ways to control 
emissions of PM2.5 and PM2.5 precursors from 
sources in various industries, including the pulp and paper industry, 
from a 2006 State and Territorial Air Pollution Program Administrators/
Association of Local Air Pollution Control Officers (STAPPA/ALAPCO) 
document, titled Controlling Fine Particulate Matter under the Clean 
Air Act: A Menu of Options.
     Stack test data submitted with ICR responses.
     Emissions factors from technical bulletins prepared by the 
National Council for Air and Stream Improvement, Inc. (NCASI), a major 
source of environmental data affecting the pulp and paper industry.

III. Analytical Procedures

    In this section, we describe the analyses performed to support the 
proposed decisions for the RTR and other issues addressed in this 
proposal.

A. How did we estimate post-MACT risks posed by the source category?

    The EPA conducted a risk assessment that provides estimates of the 
MIR posed by the HAP emissions from each source in the source category, 
the hazard index (HI) for chronic exposures to HAPs with the potential 
to cause non-cancer health effects, and the hazard quotient (HQ) for 
acute exposures to HAPs with the potential to cause non-cancer health 
effects. The assessment also provides estimates of the distribution of 
cancer risks within the exposed populations, cancer incidence, and an 
evaluation of the potential for adverse environmental effects. The 
seven sections that follow this paragraph describe how we estimated 
emissions and conducted the risk assessment. The docket for this 
rulemaking contains the following document which provides more 
information on the risk assessment inputs and models: Residual Risk 
Assessment for Pulp Mill Combustion Sources in Support of the December 
2016 Risk and Technology Review Proposed Rule. The methods used to 
assess risks (as described in the seven primary steps below) are 
consistent with those peer-reviewed by a panel of the EPA's Science 
Advisory Board (SAB) in 2009 and described in their peer review report 
issued in 2010; \2\ they are also consistent with the key

[[Page 97053]]

recommendations contained in that report.
---------------------------------------------------------------------------

    \2\ U.S. EPA SAB. Risk and Technology Review (RTR) Risk 
Assessment Methodologies: For Review by the EPA's Science Advisory 
Board with Case Studies--MACT I Petroleum Refining Sources and 
Portland Cement Manufacturing, May 2010.
---------------------------------------------------------------------------

1. How did we estimate actual emissions and identify the emissions 
release characteristics?
    As discussed in section II.C of this preamble, we used data from 
Part II of the Pulp and Paper Sector ICR as the basis for the risk 
assessments for the pulp and paper sector (including 40 CFR part 63, 
subparts S and MM). Part II of the ICR, which concluded in June 2011, 
targeted facilities that are major sources of HAP emissions and 
involved an update of pre-populated NEI data spreadsheets (or creation 
of new datasets). The NEI is a database that contains information about 
sources that emit criteria air pollutants, their precursors and HAPs. 
The NEI database includes estimates of actual annual air pollutant 
emissions from point and volume sources; emission release 
characteristic data such as emission release height, temperature, 
diameter, velocity, and flow rate; and locational latitude/longitude 
coordinates. We asked pulp and paper mills to refine (or create new) 
inventories based on their NEI datasets for purposes of detailed 
residual risk modeling. Refinements included providing additional 
details for HAP emission sources, providing more specific information 
on the location and characteristics of emission points (e.g., updating 
emission release coordinates and parameters), and adding or updating 
HAP emissions data for each emission release point. We compiled the 
updated datasets for each individual mill into a pulp and paper Part II 
emissions database to create the whole facility and MACT source 
category residual risk modeling files.
    The actual annual emissions data in the pulp and paper emissions 
database include limited data from actual emissions tests and, in most 
cases, estimates of actual emissions (based on emissions factors) 
provided by sources surveyed in Part II of the ICR. We received a 
comprehensive set of emissions test data and emissions estimates that 
enabled us to conduct risk modeling of detectable HAP emissions for all 
major source facilities in the MACT source category.
    We conducted two substantial quality assurance (QA) efforts on the 
Part II data in order to create the modeling files needed for the 40 
CFR part 63, subpart S residual risk assessment, which included: (1) QA 
of the updated inventory spreadsheets submitted by each mill prior to 
import into the compiled database; and (2) QA and standardization of 
the compiled database.\3\ We needed modeling files for both the subpart 
S category and the whole facility, so our QA efforts focused on data 
for all emission sources at pulp and paper facilities, including 40 CFR 
part 63, subpart MM emission sources.
---------------------------------------------------------------------------

    \3\ These QA efforts are discussed in a November 11, 2011 
memorandum in the docket, titled Inputs to the Pulp and Paper 
Industry October 2011 Residual Risk Modeling.
---------------------------------------------------------------------------

    We reviewed the Part II datasets to ensure that the major pulp and 
paper processes and pollutants were included and properly identified, 
to ensure that emissions from the various processes were allocated to 
the correct source category, and to identify emissions and other data 
anomalies. We also standardized the various codes (e.g., source 
classification codes (SCCs), pollutant codes), eliminated duplicate 
records, and checked geographic coordinates. We reviewed emissions 
release parameters for data gaps and errors, assigned the proper 
default parameters where necessary, assigned emission process groups to 
distinguish between processes with related SCCs, and ensured that 
fugitive release dimensions were specified or given default values 
where necessary.
    We requested comments on the inventory in the preamble to the 
December 27, 2011, 40 CFR part 63, subpart S proposal. We requested 
further updates to the mill-specific HAP emissions data used in the 
risk modeling, if needed. In 2012, we received revisions to inventories 
for 81 facilities following proposal of the subpart S residual risk 
review.\4\
---------------------------------------------------------------------------

    \4\ Review of the inventory revisions performed prior to 
promulgation of 40 CFR part 63, subpart S is documented in a May 8, 
2012, memorandum in the subpart S docket (EPA-HQ-OAR-2007-0544), 
titled Recommendations Concerning Residual Risk Remodeling for the 
Pulp and Paper Industry.
---------------------------------------------------------------------------

    While most of the inventory revisions that we received after the 
proposal made additional refinements to emissions levels and release 
point details for 40 CFR part 63, subpart S sources, some inventory 
revisions also made refinements to data for 40 CFR part 63, subpart MM 
sources. We incorporated revisions to all process types into the 
inventory to remodel facility-wide risk and perform the complete scope 
of residual risk modeling for subpart MM emissions sources. We checked 
the 81 individual revision files to ensure they were incorporated into 
the main database correctly, and then further reviewed the entire 
database.
    We began compiling an initial draft residual risk modeling input 
file for use in the 40 CFR part 63, subpart MM residual risk review in 
September 2014.\5\ We made updates to the mill list to account for 
facilities that recently closed or reopened, and to mill equipment 
configurations for facilities that recently upgraded equipment. We 
reviewed the inventory to ensure that each record contained a facility 
ID, emission unit ID, process ID, and emission release point ID. We 
cross-walked regulatory codes, SCCs, and emission process groups to 
identify and correct any inconsistencies that may have been introduced 
with the inventory updates.
---------------------------------------------------------------------------

    \5\ For more information, see the September 30, 2014 memorandum 
in the docket, titled Preparation of Residual Risk Modeling Input 
File for Subpart MM. The September 2014 memorandum describes the 
source of the inventory data, discusses quality assurance of the 40 
CFR part 63, subpart MM data, provides actual versus allowable and 
acute risk multipliers for subpart MM sources, and identifies 
potential outliers and suspect data for further review.
---------------------------------------------------------------------------

    In addition to retaining the emission process groups used in the 
previous 40 CFR part 63, subpart S modeling effort, we added new 
emission process groups for 40 CFR part 63, subpart MM sources where 
necessary. We compared the subpart MM emission process groups with the 
Part III ICR database to ensure that we included all known recovery 
furnaces and lime kilns in the inventory for the residual risk 
modeling. In addition, we reviewed the presence or absence of BLO 
systems (i.e., because BLO systems are only expected to be present at 
mills with direct contact evaporator (DCE) recovery furnaces). Finally, 
we checked the mills to ensure emission process groups included SDTs 
and sulfite and semichemical recovery equipment, as expected.
    We reviewed the pollutant codes in the inventory to ensure the 
codes and descriptions matched the latest NEI lookup table used by the 
EPA for risk model input files. We performed extensive QA of the 
pollutant codes prior to the 40 CFR part 63, subpart S risk modeling, 
so few updates were required.
    We speciated data for a number of HAPs, including chromium, 
mercury, radionuclides, polycyclic organic matter (POM), and dioxins/
furans to facilitate risk modeling. We speciated chromium emissions as 
hexavalent chromium (chromium VI) and trivalent chromium (chromium 
III).\6\ We speciated mercury emissions as particulate divalent 
mercury, gaseous divalent mercury, and gaseous elemental mercury. We 
speciated total POM emissions differently for each emission unit type

[[Page 97054]]

based on the most common POM compounds emitted from that unit. We 
speciated dioxin/furan emissions based on published emissions data in 
the EPA's dioxin/furan inventory report \7\ or, if no speciation 
profile was available, recalculated the emissions using published 
emissions factors.\8\ Where needed, we added/replaced emissions 
estimates that were omitted, outdated, out-of-scope, or inconsistent 
with changes to mill equipment configurations.
---------------------------------------------------------------------------

    \6\ For more information on pollutant speciation, see the 
September 30, 2014 memorandum in the docket, titled Preparation of 
Residual Risk Modeling Input File for Subpart MM.
    \7\ U.S. Environmental Protection Agency. An Inventory of 
Sources and Environmental Releases of Dioxin-Like Compounds in the 
United States for the Years 1987, 1995, and 2000. Publication No. 
EPA/600/P-03/002F. Available at: http://www.epa.gov/ncea/pdfs/dioxin/2006/dioxin.pdf. November 2006. Tables 4-14, 4-25, and 5-13.
    \8\ National Council for Air and Stream Improvement (NCASI). 
Compilation of `Air Toxic' and Total Hydrocarbon Emissions Data for 
Pulp and Paper Mill Sources--A Second Update. Technical Bulletin No. 
973. February 2010. Table 9.9.
---------------------------------------------------------------------------

    We reviewed all records for consistency with respect to the 
emission release point to ensure each record was characterized by one 
set of coordinates (latitude and longitude) and one set of stack or 
fugitive parameters. We checked fugitive parameters to ensure there 
were no blanks and that the values provided were reasonable and 
consistent with the required national defaults or other criteria. We 
reviewed emission points labeled as stacks to ensure no fugitive 
parameters were identified. We checked exit gas flow rate values 
against the stack velocity provided to ensure there were no 
inconsistencies. We mapped the emission point coordinates for each 
facility to determine if they were properly placed on the mill site. We 
also added control information from the Part III ICR database or mills' 
title V permits to the input file for 40 CFR part 63, subpart MM 
sources.
    The emissions inventory for 40 CFR part 63, subpart MM sources 
identifies emissions of the following HAP known to be persistent and 
bio-accumulative in the environment (PB-HAPs): Cadmium compounds, lead 
compounds, mercury compounds, POM, dioxins/furans, and 
hexachlorobenzene. Risk-based screening levels are available for Tier 1 
screening for all of the above PB-HAPs, with the exception of 
hexachlorobenzene.
    Consistent with the EPA's standard practice in conducting risk 
assessments for source categories, we conducted a two-step process to 
determine: (1) Whether PB-HAPs are being emitted; and (2) whether they 
are being released above screening levels. If these releases are 
significantly above the screening levels and the EPA has detailed 
information on the releases and the site, a complete multipathway 
analysis of the site is conducted to estimate pathway risks for the 
source category.
    We considered actual emissions of the ecological HAPs emitted from 
the 40 CFR part 63, subpart MM source category in the ecological HAP 
analysis. In addition to the PB-HAPs emitted from the subpart MM source 
category (except hexachlorobenzene), we considered hydrochloric acid 
(HCl) and hydrogen fluoride (HF) for ecological HAP modeling. Further 
information about the multipathway analysis performed for this category 
follows in section III.B.4 of this preamble.
    In 2015, we posted the initial draft risk model input file on our 
Technology Transfer Network for additional review by interested 
parties. This review resulted in the submittal of additional mill-
specific inventory and receptor revisions. As part of the review, we 
identified potential outliers and suspect data for 40 CFR part 63, 
subpart MM sources in the emission inventory and notified facilities to 
provide an opportunity to review and revise their emissions data, if 
needed. A total of 40 mills reviewed their emissions data, with 38 of 
those mills submitting inventory revisions to the EPA.\9\
---------------------------------------------------------------------------

    \9\ For further information, see the October 16, 2015 memorandum 
in the docket, titled Review of Pulp Mill Inventory Revisions 
Received in 2015.
---------------------------------------------------------------------------

    Inventory revisions primarily included mill name changes; revisions 
to HAP metal, POM, and dioxin/furan inventory data; and requests for 
removal of hexachlorocyclopentadiene (HCCPD) data from inventories, 
particularly for SDTs, since HCCPD is not expected from pulp mill 
sources. Where necessary, we speciated the revised chromium, mercury, 
and POM data that the mills provided, using the approaches described 
above. As part of the review, we identified risk modeling receptors 
improperly located on mill property for correction in the Human 
Exposure Model (Community and Sector HEM-3 version 1.1.0) input files 
before we performed risk modeling for 40 CFR part 63, subpart MM.
    After we incorporated the revisions into the input file, we 
conducted an additional review of the file, which included the 
following:
     Identified non-40 CFR part 63, subpart MM mills in the 
inventory and removed them.
     Identified additional mill name changes and incorporated 
them in the inventory.
     Reviewed fugitive parameters for missing data.
     Identified missing speciated mercury and chromium data and 
restored the data to the inventory.
     Reviewed location data for mills that submitted inventory 
revisions and corrected coordinates, as needed.
     Identified records for emissions points with zero 
emissions for a given pollutant and removed those records from the 
inventory.
     Conducted emission process group checks, resulting in a 
revision to an emission process group that reflects a change in SCC, 
and removal of records with an emission process group no longer 
applicable (specifically a BLO unit for a mill that no longer operates 
any DCE recovery furnaces that require a BLO unit).
     Checked mills to ensure they had the expected 40 CFR part 
63, subpart MM equipment, comparing the number of recovery furnaces, 
lime kilns, and SDTs to Part III ICR data to ensure each emission unit 
was represented in the inventory.
     Reviewed each emission unit for the presence of an 
emissions value for key expected pollutants (e.g., HAP metals, HCl, 
methanol, dioxins/furans, POM) and added emissions estimates for those 
pollutants where needed.\10\
---------------------------------------------------------------------------

    \10\ For further information, see the February 16, 2016 
memorandum in the docket, titled Approach for Populating Missing and 
Erroneous Emissions Estimates for Key HAP in the Subpart MM Residual 
Risk Modeling Inventory.
---------------------------------------------------------------------------

     Replaced obviously errant emissions data (particularly 
dioxins/furans) with revised estimates calculated based on ICR-reported 
throughput and emissions factors.
     Rechecked IDs, SCCs, regulatory codes, pollutant codes, 
duplicate pollutants, and HCCPD deletions.
2. How did we estimate MACT-allowable emissions?
    The available emissions data in the RTR emissions dataset include 
estimates of the mass of HAPs emitted during the specified annual time 
period. In some cases, these ``actual'' emission levels are lower than 
the emission levels required to comply with the current MACT standards. 
The emissions level allowed to be emitted by the MACT standards is 
referred to as the ``MACT-allowable'' emissions level. We discussed the 
use of both MACT-allowable and actual emissions in the final Coke Oven 
Batteries RTR (70 FR 19998-19999, April 15, 2005) and in the proposed 
and final Hazardous Organic NESHAP RTRs (71 FR 34428, June 14, 2006, 
and 71 FR 76609, December 21, 2006, respectively). In those actions, we 
noted that assessing the risks at the MACT-allowable level is 
inherently reasonable

[[Page 97055]]

since these risks reflect the maximum level facilities could emit and 
still comply with national emission standards. 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 approach. (54 FR 38044, September 14, 1989.) It is 
reasonable to consider actual emissions because sources typically seek 
to perform better than required by emissions standards to provide an 
operational margin to accommodate the variability in manufacturing 
processes and control device performance. Facilities' actual emissions 
may also be significantly lower than MACT-allowable emissions for other 
reasons such as state requirements, better performance of control 
devices than required by the MACT standards, or reduced production.
    We estimated actual emissions based on the Part II emissions 
inventory and subsequent site-specific inventory revisions provided by 
mills. To estimate emissions at the MACT-allowable level, we developed 
a ratio of MACT-allowable emissions to actual emissions for each source 
type for the facilities in the 40 CFR part 63, subpart MM source 
category. We developed this ratio based on the level of control 
required by the subpart MM MACT standards compared to the level of 
reported actual emissions from stack test reports provided with Part 
III survey responses. For example, stack test data indicated that SDTs 
achieve PM levels of 0.108 pounds per ton (lb/ton) black liquor solids 
(BLS), on average, while the PM emission limit for existing SDTs is 
0.20 lb/ton BLS, so we estimated that MACT-allowable emissions of HAP 
metals from SDTs (where PM is used as a surrogate) could be as much as 
1.8 times higher, and the ratio of MACT-allowable to actual emissions 
used was 1.8:1 for SDTs.\11\
---------------------------------------------------------------------------

    \11\ For more information, see the September 30, 2014 memorandum 
in the docket, titled Preparation of Residual Risk Modeling Input 
File for Subpart MM.
---------------------------------------------------------------------------

    After developing these ratios for each emission point type in this 
source category, we next applied these ratios on an emission unit basis 
to the Part II actual emissions data to obtain risk estimates based on 
MACT-allowable emissions.
3. How did we conduct dispersion modeling, determine inhalation 
exposures and estimate individual and population inhalation risks?
    Both long-term and short-term inhalation exposure concentrations 
and health risks from the source category addressed in this proposal 
were estimated using HEM-3. The HEM-3 performs three primary risk 
assessment activities: (1) Conducting dispersion modeling to estimate 
the concentrations of HAPs in ambient air, (2) estimating long-term and 
short-term inhalation exposures to individuals residing within 50 
kilometers (km) of the modeled sources,\12\ and (3) estimating 
individual and population-level inhalation risks using the exposure 
estimates and quantitative dose-response information.
---------------------------------------------------------------------------

    \12\ This metric comes from the Benzene NESHAP. See 54 FR 38046.
---------------------------------------------------------------------------

    The air dispersion model used by the HEM-3 model (AERMOD) is one of 
the EPA's preferred models for assessing pollutant concentrations from 
industrial facilities.\13\ 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 (2014) of 
hourly surface and upper air observations for more than 800 
meteorological stations, selected to provide coverage of the United 
States and Puerto Rico. A second library of United States Census Bureau 
census block \14\ internal point locations and populations provides the 
basis of human exposure calculations (U.S. Census, 2010). In addition, 
for each census block, the census library includes the elevation and 
controlling hill height, 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 the EPA for 
HAPs and other toxic air pollutants. These values are available at 
https://www.epa.gov/fera/dose-response-assessment-assessing-health-risks-associated-exposure-hazardous-air-pollutants and are discussed in 
more detail later in this section.
---------------------------------------------------------------------------

    \13\ 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).
    \14\ A census block is the smallest geographic area for which 
census statistics are tabulated.
---------------------------------------------------------------------------

    In developing the risk assessment for chronic exposures, we used 
the estimated annual average ambient air concentrations of each 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 continuous lifetime (24 hours per day, 7 days per week, and 52 weeks 
per year for a 70-year period) exposure to the maximum concentration at 
the centroid of inhabited census blocks. Individual cancer risks were 
calculated by multiplying the estimated lifetime exposure to the 
ambient concentration of each of the HAP (in micrograms per cubic meter 
([mu]g/m\3\)) by its unit risk estimate (URE). The URE 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 the EPA's Integrated Risk Information 
System (IRIS). For carcinogenic pollutants without IRIS values, we look 
to other reputable sources of cancer dose-response values, often using 
California EPA (CalEPA) URE values, where available. In cases where 
new, scientifically credible dose response values have been developed 
in a manner consistent with the EPA guidelines and have undergone a 
peer review process similar to that used by the EPA, we may use such 
dose-response values in place of, or in addition to, other values, if 
appropriate.
    The EPA estimated incremental individual lifetime cancer risks 
associated with emissions from the facilities in the source category 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 \15\) emitted 
by the modeled sources. Cancer incidence and the distribution of 
individual cancer risks for the population within 50 km of the

[[Page 97056]]

sources were also estimated for the source category as part of this 
assessment by summing individual risks. A distance of 50 km is 
consistent with both the analysis supporting the 1989 Benzene NESHAP 
(54 FR 38044, September 14, 1989) and the limitations of Gaussian 
dispersion models, including AERMOD.
---------------------------------------------------------------------------

    \15\ These classifications also coincide with the terms ``known 
carcinogen, probable carcinogen, and possible carcinogen,'' 
respectively, which are the terms advocated in the EPA's Guidelines 
for Carcinogen Risk Assessment, published in 1986 (51 FR 33992, 
September 24, 1986). In August 2000, the document Supplemental 
Guidance for Conducting Health Risk Assessment of Chemical Mixtures 
(EPA/630/R-00/002) was published as a supplement to the 1986 
document. Copies of both documents can be obtained from https://cfpub.epa.gov/ncea/risk/recordisplay.cfm?deid=20533&CFID=70315376&CFTOKEN=71597944. 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 the EPA's National Air Toxics Assessment 
(NATA) titled, 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.
---------------------------------------------------------------------------

    To assess the 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 value, which is a value selected from 
one of several sources. First, the chronic reference level can be the 
EPA reference concentration (RfC) (https://iaspub.epa.gov/sor_internet/registry/termreg/searchandretrieve/glossariesandkeywordlists/search.do?details=&vocabName=IRIS%20Glossary), 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.'' Alternatively, in cases 
where an RfC from the EPA's IRIS database is not available or where the 
EPA determines that using a value other than the RfC is appropriate, 
the chronic reference level can be a value from the following 
prioritized sources: (1) The Agency for Toxic Substances and Disease 
Registry (ATSDR) Minimum Risk Level (http://www.atsdr.cdc.gov/mrls/index.asp), which is defined as ``an estimate of daily human exposure 
to a hazardous substance that is likely to be without an appreciable 
risk of adverse non-cancer health effects (other than cancer) over a 
specified duration of exposure''; (2) the CalEPA Chronic Reference 
Exposure Level (REL) (http://oehha.ca.gov/air/crnr/notice-adoption-air-toxics-hot-spots-program-guidance-manual-preparation-health-risk-0), 
which is defined as ``the concentration level (that is expressed in 
units of micrograms per cubic meter ([mu]g/m\3\) for inhalation 
exposure and in a dose expressed in units of milligram per kilogram-day 
(mg/kg-day) for oral exposures), at or below which no adverse health 
effects are anticipated for a specified exposure duration''; or (3), as 
noted above, a scientifically credible dose-response value that has 
been developed in a manner consistent with the EPA guidelines and has 
undergone a peer review process similar to that used by the EPA, in 
place of or in concert with other values.
    As mentioned above, in order to characterize non-cancer chronic 
effects, and in response to key recommendations from the SAB, the EPA 
selects dose-response values that reflect the best available science 
for all HAPs included in RTR risk assessments.\16\ More specifically, 
for a given HAP, the EPA examines the availability of inhalation 
reference values from the sources included in our tiered approach 
(e.g., IRIS first, ATSDR second, CalEPA third) and determines which 
inhalation reference value represents the best available science. Thus, 
as new inhalation reference values become available, the EPA will 
typically evaluate them and determine whether they should be given 
preference over those currently being used in RTR risk assessments.
---------------------------------------------------------------------------

    \16\ The SAB peer review of RTR Risk Assessment Methodologies is 
available at http://yosemite.epa.gov/sab/sabproduct.nsf/
4AB3966E263D943A8525771F00668381/$File/EPA-SAB-10-007-unsigned.pdf.
---------------------------------------------------------------------------

    The EPA also evaluated screening estimates of acute exposures and 
risks for each of the HAP (for which appropriate acute dose-response 
values are available) at the point of highest potential off-site 
exposure for each facility. To do this, the EPA estimated the risks 
when both the peak (hourly) emissions rate and worst-case dispersion 
conditions occur. We also assume that a person is located at the point 
of highest impact during that same time. In accordance with our mandate 
in section 112 of the CAA, we use the point of highest off-site 
exposure to assess the potential risk to the maximally exposed 
individual. The acute HQ is the estimated acute exposure divided by the 
acute dose-response value. In each case, the EPA calculated acute HQ 
values using best available, short-term dose-response values. These 
acute dose-response values, which are described below, include the 
acute 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 emissions rates, 
meteorology, and exposure location.
    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://oehha.ca.gov/air/general-info/oehha-acute-8-hour-and-chronic-reference-exposure-level-rel-summary) is defined as ``the concentration level at 
or below which no adverse health effects are anticipated for a 
specified exposure duration.'' Id. at page 2. Acute REL values are 
based on the most sensitive, relevant, adverse health effect reported 
in the peer-reviewed medical and toxicological literature. Acute REL 
values are designed to protect the most sensitive individuals in the 
population through the inclusion of margins of safety. Because margins 
of safety are incorporated to address data gaps and uncertainties, 
exceeding the REL does not automatically indicate an adverse health 
impact.
    Acute exposure guideline level values were derived in response to 
recommendations from the National Research Council (NRC). The National 
Advisory Committee (NAC) for the Development of Acute Exposure 
Guideline Levels for Hazardous Substances--usually referred to as the 
AEGL Committee or the NAC/AEGL committee developed AEGL values for at 
least 273 of the 329 chemicals on the AEGL priority chemical list. The 
last meeting of the NAC/AEGL Committee was in April 2010, and its 
charter expired in October 2011. The NAC/AEGL Committee ended in 
October 2011, but the AEGL program continues to operate at the EPA and 
works with the National Academies to publish final AEGLs (https://www.epa.gov/aegl).
    As described in Standing Operating Procedures (SOP) for Developing 
Acute Exposure Guideline Levels for Hazardous Substances, ``The NRC's 
previous name for acute exposure levels--community emergency exposure 
levels--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'' (https://www.epa.gov/aegl/process-developing-acute-exposure-guideline-levels-aegls) Id. at 2.\17\ The AEGL values 
represent threshold exposure limits for the general public and are 
applicable to emergency exposures ranging from 10 minutes to 8 hours. 
``The primary purpose of the AEGL program is to develop guideline 
levels for once-in-a-lifetime, short-term exposures to airborne 
concentrations of acutely toxic, high-priority chemicals.'' Id. at 21. 
``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

[[Page 97057]]

emergency response actions, for accidental chemical releases at fixed 
facilities and from transport carriers.'' Id. at 31.
---------------------------------------------------------------------------

    \17\ National Academy of Sciences (NAS), 2001. Standing 
Operating Procedures for Developing Acute Exposure Levels for 
Hazardous Chemicals, page 2.
---------------------------------------------------------------------------

    The AEGL-1 value is then specifically defined as ``the airborne 
concentration (expressed as ppm (parts per million) or mg/m3 
(milligrams per cubic meter)) 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.'' Id. at 3. The document also notes 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.'' Id. Similarly, the document defines AEGL-2 values as ``the 
airborne concentration (expressed as parts per million or milligrams 
per cubic meter) 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.'' Id.
    Emergency response planning guideline values are derived for use in 
emergency response, as described in the American Industrial Hygiene 
Association's Emergency Response Planning (ERP) Committee document 
titled, ERPGS Procedures and Responsibilities (https://www.aiha.org/get-involved/AIHAGuidelineFoundation/EmergencyResponsePlanningGuidelines/Documents/ERPG%20Committee%20Standard%20Operating%20Procedures%20%20-%20March%202014%20Revision%20%28Updated%2010-2-2014%29.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.'' \18\ Id. at 1. The 
ERPG-1 value is defined as ``the maximum airborne concentration below 
which nearly all individuals could be exposed for up to 1 hour without 
experiencing more than mild, transient health effects or without 
perceiving a clearly defined, objectionable odor.'' Id. at 2. 
Similarly, the ERPG-2 value is defined as ``the maximum airborne 
concentration below which nearly all individuals could be exposed for 
up to 1 hour without experiencing or developing irreversible or other 
serious adverse health effects or symptoms that could impair an 
individual's ability to take protective action.'' Id. at 1.
---------------------------------------------------------------------------

    \18\ ERP Committee Procedures and Responsibilities. November 1, 
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 
because the types of effects for these chemicals are not consistent 
with the AEGL-1/ERPG-1 definitions; in these instances, we compare 
higher severity level AEGL-2 or ERPG-2 values to our modeled exposure 
levels to screen for potential acute concerns. When AEGL-1/ERPG-1 
values are available, they are used in our acute risk assessments.
    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 
dose-response value (usually the AEGL-1 and/or the ERPG-1 value).
    To develop screening estimates of acute exposures in the absence of 
hourly emissions data, generally we first develop estimates of maximum 
hourly emissions rates by multiplying the average actual annual hourly 
emissions rates by a default factor to cover routinely variable 
emissions. We choose the factor to use partially based on process 
knowledge and engineering judgment. The factor chosen also reflects a 
Texas study of short-term volatile organic compound (VOC) emissions 
variability, which showed that most peak emission events in a heavily-
industrialized four-county area (Harris, Galveston, Chambers, and 
Brazoria Counties, Texas) were less than twice the annual average 
hourly emissions rate. The highest peak emissions event was 74 times 
the annual average hourly emissions rate, and the 99th percentile ratio 
of peak hourly emissions rate to the annual average hourly emissions 
rate was 9.\19\ Considering this analysis, to account for more than 99 
percent of the peak hourly emissions, we apply a conservative screening 
multiplication factor of 10 to the average annual hourly emissions rate 
in our acute exposure screening assessments as our default approach. 
However, we use a factor other than 10 if we have information that 
indicates that a different factor is appropriate for a particular 
source category. For this source category, median peak-to-mean 
multipliers ranging from 1.1 to 4.7 were developed for 40 CFR part 63, 
subpart MM emission process groups based on the routine annual 
emissions data and peak hourly emissions data obtained from Part II 
survey data. A further discussion of why these factors were chosen can 
be found in the memorandum, Preparation of Residual Risk Modeling Input 
File for Subpart MM, available in the docket for this rulemaking.
---------------------------------------------------------------------------

    \19\ Allen, et al., 2004. Variable Industrial VOC Emissions and 
their impact on ozone formation in the Houston Galveston Area. Texas 
Environmental Research Consortium. https://www.researchgate.net/publication/237593060_Variable_Industrial_VOC_Emissions_and_their_Impact_on_Ozone_Formation_in_the_Houston_Galveston_Area.
---------------------------------------------------------------------------

    As part of our acute risk assessment process, for cases where acute 
HQ values from the screening step were less than or equal to 1 (even 
under the conservative assumptions of the screening analysis), acute 
impacts were deemed negligible and no further analysis was performed 
for these HAPs. See the Residual Risk Assessment for Pulp Mill 
Combustion Sources in Support of the December 2016 Risk and Technology 
Review Proposed Rule for more details. 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 
emissions 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. Recognizing that this level of data 
is rarely available, we instead rely on the multiplier approach.
    To better characterize the potential health risks associated with 
estimated acute exposures to HAPs, and in response to a key 
recommendation from the SAB's peer review of the EPA's RTR risk 
assessment methodologies,\20\ we generally examine a wider range of 
available acute health metrics (e.g., RELs, AEGL) than we do for our 
chronic risk assessments. This is in response to

[[Page 97058]]

the SAB's acknowledgement that there are generally more data gaps and 
inconsistencies in acute reference values than there are in chronic 
reference values. In some cases, when Reference Value Arrays \21\ for 
HAPs have been developed, we consider additional acute values (i.e., 
occupational and international values) to provide a more complete risk 
characterization.
---------------------------------------------------------------------------

    \20\ The SAB peer review of RTR Risk Assessment Methodologies is 
available at http://yosemite.epa.gov/sab/sabproduct.nsf/
4AB3966E263D943A8525771F00668381/$File/EPA-SAB-10-007-unsigned.pdf.
    \21\ U.S. EPA. (2009) Chapter 2.9, Chemical Specific Reference 
Values for Formaldehyde in Graphical Arrays of Chemical-Specific 
Health Effect Reference Values for Inhalation Exposures (Final 
Report). U.S. Environmental Protection Agency, Washington, DC, EPA/
600/R-09/061, 2009, and available online at http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=211003.
---------------------------------------------------------------------------

4. How did we conduct the multipathway exposure and risk screening?
    The EPA conducted a screening analysis examining the potential for 
significant human health risks due to exposures via routes other than 
inhalation (i.e., ingestion). We first determined whether any sources 
in the source category emitted PB-HAP. The PB-HAP compounds or compound 
classes are identified for the screening from the EPA's Air Toxics Risk 
Assessment Library (available at http://www2.epa.gov/fera/risk-assessment-and-modeling-air-toxics-risk-assessment-reference-library).
    For the 40 CFR part 63, subpart MM source category, we identified 
emissions of cadmium compounds, lead compounds, mercury compounds, POM, 
dioxins/furans, and hexachlorobenzene. Because one or more of these PB-
HAPs are emitted by at least one facility in the subpart MM source 
category, we proceeded to the next step of the evaluation. In this 
step, we determined whether the facility-specific emissions rates of 
the emitted PB-HAP were large enough to create the potential for 
significant non-inhalation human health risks under reasonable worst-
case conditions. To facilitate this step, we have developed emissions 
rate screening levels for several PB-HAPs using a hypothetical upper-
end screening exposure scenario developed for use in conjunction with 
the EPA's Total Risk Integrated Methodology Fate, Transport, and 
Ecological Exposure (TRIM.FaTE) model. The PB-HAPs with emissions rate 
screening levels are: Lead, cadmium, dioxins/furans, mercury compounds, 
and POM. We conducted a sensitivity analysis on the screening scenario 
to ensure that its key design parameters would represent the upper end 
of the range of possible values, such that it would represent a 
conservative, but not impossible, scenario. The facility-specific 
emissions for each PB-HAP were compared to the emission rate screening 
levels for these PB-HAPs to assess the potential for significant human 
health risks via non-inhalation pathways. We call this application of 
the TRIM.FaTE model the Tier 1 TRIM-screen or Tier 1 screen.
    For the purpose of developing emission rate screening values for 
our Tier 1 TRIM-screen, we derived emission levels for these PB-HAPs 
(other than lead compounds) at which the maximum excess lifetime cancer 
risk would be 1-in-1 million (i.e., for dioxins/furans and POM) or, for 
HAPs that cause non-cancer health effects (i.e., cadmium compounds and 
mercury compounds), the maximum HQ would be 1. If the emissions rate of 
any PB-HAP included in the Tier 1 screen exceeds the Tier 1 screening 
emissions level for any facility, we conduct a second screen, which we 
call the Tier 2 TRIM-screen or Tier 2 screen.
    In the Tier 2 screen, the location of each facility that exceeded 
the Tier 1 emission level is used to refine the assumptions associated 
with the environmental scenario while maintaining the exposure scenario 
assumptions. A key assumption that is part of the Tier 1 screen is that 
a lake is located near the facility; we confirm the existence of lakes 
near the facility as part of the Tier 2 screen. We then adjust the 
risk-based Tier 1 screening value for each PB-HAP for each facility 
based on an understanding of how exposure concentrations estimated for 
the screening scenario change with meteorology and environmental 
assumptions. PB-HAP emissions that do not exceed these new Tier 2 
screening levels are considered to pose no unacceptable risks. If the 
PB-HAP emissions for a facility exceed the Tier 2 screening levels and 
data are available, we may decide to conduct a more refined Tier 3 
multipathway assessment. There are several analyses that can be 
included in a Tier 3 screen depending upon the extent of refinement 
warranted, including validating that the lake is fishable and 
considering plume-rise to estimate emissions lost above the mixing 
layer. If the Tier 3 screen is exceeded, the EPA may further refine the 
assessment.
    In evaluating the potential multipathway risk from emissions of 
lead compounds, rather than developing a screening emissions rate for 
them, we compared maximum estimated chronic inhalation exposures with 
the level of the current National Ambient Air Quality Standard (NAAQS) 
for lead.\22\ Values below the level of the primary (health-based) lead 
NAAQS were considered to have a low potential for multipathway risk.
---------------------------------------------------------------------------

    \22\ In doing so, the EPA notes that the legal standard for a 
primary NAAQS--that a standard is requisite to protect public health 
and provide an adequate margin of safety (CAA section 109(b))--
differs from the CAA section 112(f) standard (requiring among other 
things that the standard provide an ``ample margin of safety''). 
However, the primary lead NAAQS is a reasonable measure of 
determining risk acceptability (i.e., the first step of the Benzene 
NESHAP analysis) since it is designed to protect the most 
susceptible group in the human population--children, including 
children living near major lead emitting sources. 73 FR 67002/3; 73 
FR 67000/3; 73 FR 67005/1. In addition, applying the level of the 
primary lead NAAQS at the risk acceptability step is conservative, 
since that primary lead NAAQS reflects an adequate margin of safety.
---------------------------------------------------------------------------

    For further information on the multipathway analysis approach, see 
the document titled Residual Risk Assessment for Pulp Mill Combustion 
Sources in Support of the December 2016 Risk and Technology Review 
Proposed Rule, which is available in the docket for this action.
5. How did we conduct the environmental risk screening assessment?
a. Adverse Environmental Effect
    The EPA conducts a screening assessment to examine the potential 
for adverse environmental effects as required under section 
112(f)(2)(A) of the CAA. Section 112(a)(7) of the CAA defines ``adverse 
environmental effect'' as ``any significant and widespread adverse 
effect, which may reasonably be anticipated, to wildlife, aquatic life, 
or other natural resources, including adverse impacts on populations of 
endangered or threatened species or significant degradation of 
environmental quality over broad areas.''
b. Environmental HAPs
    The EPA focuses on seven HAPs, which we refer to as ``environmental 
HAPs,'' in its screening analysis: Five PB-HAPs and two acid gases. The 
five PB-HAPs are cadmium, dioxins/furans, POM, mercury (both inorganic 
mercury and methyl mercury) and lead compounds. The two acid gases are 
HCl and HF. The rationale for including these seven HAPs in the 
environmental risk screening analysis is presented below.
    The HAPs that persist and bioaccumulate are of particular 
environmental concern because they accumulate in the soil, sediment, 
and water. The PB-HAPs are taken up, through sediment, soil, water, 
and/or

[[Page 97059]]

ingestion of other organisms, by plants or animals (e.g., small fish) 
at the bottom of the food chain. As larger and larger predators consume 
these organisms, concentrations of the PB-HAPs in the animal tissues 
increases as does the potential for adverse effects. The five PB-HAPs 
we evaluate as part of our screening analysis account for 99.8 percent 
of all PB-HAP emissions nationally from stationary sources (on a mass 
basis from the 2005 EPA NEI).
    In addition to accounting for almost all of the mass of PB-HAPs 
emitted, we note that the TRIM.FaTE model that we use to evaluate 
multipathway risk allows us to estimate concentrations of cadmium 
compounds, dioxins/furans, POM, and mercury in soil, sediment and 
water. For lead compounds, we currently do not have the ability to 
calculate these concentrations using the TRIM.FaTE model. Therefore, to 
evaluate the potential for adverse environmental effects from lead 
compounds, we compare the estimated exposures from the source category 
emissions of lead with the level of the secondary NAAQS for lead.\23\ 
We consider values below the level of the secondary lead NAAQS to be 
unlikely to cause adverse environmental effects.
---------------------------------------------------------------------------

    \23\ The Secondary Lead NAAQS is a reasonable measure of 
determining whether there is an adverse environmental effect since 
it was established considering ``effects on soils, water, crops, 
vegetation, man-made materials, animals, wildlife, weather, 
visibility and climate, damage to and deterioration of property, and 
hazards to transportation, as well as effects on economic values and 
on personal comfort and well-being.''
---------------------------------------------------------------------------

    Due to their well-documented potential to cause direct damage to 
terrestrial plants, we include two acid gases, HCl and HF, in the 
environmental screening analysis. According to the 2005 NEI, HCl and HF 
account for about 99 percent (on a mass basis) of the total acid gas 
HAPs emitted by stationary sources in the United States. In addition to 
the potential to cause direct damage to plants, high concentrations of 
HF in the air have been linked to fluorosis in livestock. Air 
concentrations of these HAPs are already calculated as part of the 
human multipathway exposure and risk screening analysis using the HEM3-
AERMOD air dispersion model, and we are able to use the air dispersion 
modeling results to estimate the potential for an adverse environmental 
effect.
    The EPA acknowledges that other HAPs beyond the seven HAPs 
discussed above may have the potential to cause adverse environmental 
effects. Therefore, the EPA may include other relevant HAPs in its 
environmental risk screening in the future, as modeling science and 
resources allow. The EPA invites comment on the extent to which other 
HAPs emitted by the source category may cause adverse environmental 
effects. Such information should include references to peer-reviewed 
ecological effects benchmarks that are of sufficient quality for making 
regulatory decisions, as well as information on the presence of 
organisms located near facilities within the source category that such 
benchmarks indicate could be adversely affected.
c. Ecological Assessment Endpoints and Benchmarks for PB-HAP
    An important consideration in the development of the EPA's 
screening methodology is the selection of ecological assessment 
endpoints and benchmarks. Ecological assessment endpoints are defined 
by the ecological entity (e.g., aquatic communities including fish and 
plankton) and its attributes (e.g., frequency of mortality). Ecological 
assessment endpoints can be established for organisms, populations, 
communities or assemblages, and ecosystems.
    For PB-HAPs (other than lead compounds), we evaluated the following 
community-level ecological assessment endpoints to screen for organisms 
directly exposed to HAPs in soils, sediment, and water:
     Local terrestrial communities (i.e., soil invertebrates, 
plants) and populations of small birds and mammals that consume soil 
invertebrates exposed to PB-HAPs in the surface soil;
     Local benthic (i.e., bottom sediment dwelling insects, 
amphipods, isopods, and crayfish) communities exposed to PB-HAPs in 
sediment in nearby water bodies; and
     Local aquatic (water-column) communities (including fish 
and plankton) exposed to PB-HAP in nearby surface waters.
    For PB-HAPs (other than lead compounds), we also evaluated the 
following population-level ecological assessment endpoint to screen for 
indirect HAP exposures of top consumers via the bioaccumulation of HAPs 
in food chains:
     Piscivorous (i.e., fish-eating) wildlife consuming PB-HAP-
contaminated fish from nearby water bodies.
    For cadmium compounds, dioxins/furans, POM, and mercury, we 
identified the available ecological benchmarks for each assessment 
endpoint. An ecological benchmark represents a concentration of HAPs 
(e.g., 0.77 [mu]g of HAP per liter of water) that has been linked to a 
particular environmental effect level through scientific study. For PB-
HAPs we identified, where possible, ecological benchmarks at the 
following effect levels:
     Probable effect levels (PEL): Level above which adverse 
effects are expected to occur frequently;
     Lowest-observed-adverse-effect level (LOAEL): The lowest 
exposure level tested at which there are biologically significant 
increases in frequency or severity of adverse effects; and
     No-observed-adverse-effect levels (NOAEL): The highest 
exposure level tested at which there are no biologically significant 
increases in the frequency or severity of adverse effect.
    We established a hierarchy of preferred benchmark sources to allow 
selection of benchmarks for each environmental HAP at each ecological 
assessment endpoint. In general, the EPA sources that are used at a 
programmatic level (e.g., Office of Water, Superfund Program) were used 
in the analysis, if available. If unavailable, the EPA benchmarks used 
in regional programs (e.g., Superfund) were used. If benchmarks were 
not available at a programmatic or regional level, we used benchmarks 
developed by other federal agencies (e.g., National Oceanic and 
Atmospheric Administration (NOAA)) or state agencies.
    Benchmarks for all effect levels are not available for all PB-HAPs 
and assessment endpoints. In cases where multiple effect levels were 
available for a particular PB-HAP and assessment endpoint, we use all 
of the available effect levels to help us to determine whether 
ecological risks exist and, if so, whether the risks could be 
considered significant and widespread.
d. Ecological Assessment Endpoints and Benchmarks for Acid Gases
    The environmental screening analysis also evaluated potential 
damage and reduced productivity of plants due to direct exposure to 
acid gases in the air. For acid gases, we evaluated the following 
ecological assessment endpoint:
     Local terrestrial plant communities with foliage exposed 
to acidic gaseous HAPs in the air.
    The selection of ecological benchmarks for the effects of acid 
gases on plants followed the same approach as for PB-HAPs (i.e., we 
examine all of the available chronic benchmarks). For HCl, the EPA 
identified chronic benchmark concentrations. We note that the benchmark 
for chronic HCl exposure

[[Page 97060]]

to plants is greater than the reference concentration for chronic 
inhalation exposure for human health. This means that where the EPA 
includes regulatory requirements to prevent an exceedance of the 
reference concentration for human health, additional analyses for 
adverse environmental effects of HCl would not be necessary.
    For HF, the EPA identified chronic benchmark concentrations for 
plants and evaluated chronic exposures to plants in the screening 
analysis. High concentrations of HF in the air have also been linked to 
fluorosis in livestock. However, the HF concentrations at which 
fluorosis in livestock occur are higher than those at which plant 
damage begins. Therefore, the benchmarks for plants are protective of 
both plants and livestock.
e. Screening Methodology
    For the environmental risk screening analysis, the EPA first looked 
at whether any facilities in the 40 CFR part 63, subpart MM source 
category emitted any of the seven environmental HAPs. Because we found 
that one or more of the seven environmental HAPs evaluated are emitted 
by at least one facility in the source category, we proceeded to the 
second step of the evaluation.
f. PB-HAP Methodology
    For cadmium, mercury, POM, and dioxins/furans, the environmental 
screening analysis consists of two tiers, while lead compounds are 
analyzed differently as discussed earlier. In the first tier, we 
determined whether the maximum facility-specific emission rates of each 
of the emitted environmental HAPs were large enough to create the 
potential for adverse environmental effects under reasonable worst-case 
environmental conditions. These are the same environmental conditions 
used in the human multipathway exposure and risk screening analysis.
    To facilitate this step, TRIM.FaTE was run for each PB-HAP under 
hypothetical environmental conditions designed to provide 
conservatively high HAP concentrations. The model was set to maximize 
runoff from terrestrial parcels into the modeled lake, which in turn, 
maximized the chemical concentrations in the water, the sediments, and 
the fish. The resulting media concentrations were then used to back-
calculate a screening level emission rate that corresponded to the 
relevant exposure benchmark concentration value for each assessment 
endpoint. To assess emissions from a facility, the reported emission 
rate for each PB-HAP was compared to the screening level emission rate 
for that PB-HAP for each assessment endpoint. If emissions from a 
facility do not exceed the Tier 1 screening level, the facility 
``passes'' the screen, and, therefore, is not evaluated further under 
the screening approach. If emissions from a facility exceed the Tier 1 
screening level, we evaluate the facility further in Tier 2.
    In Tier 2 of the environmental screening analysis, the emission 
rate screening levels are adjusted to account for local meteorology and 
the actual location of lakes in the vicinity of facilities that did not 
pass the Tier 1 screen. The modeling domain for each facility in the 
Tier 2 analysis consists of 8 octants. Each octant contains 5 modeled 
soil concentrations at various distances from the facility (5 soil 
concentrations x 8 octants = total of 40 soil concentrations per 
facility) and 1 lake with modeled concentrations for water, sediment 
and fish tissue. In the Tier 2 environmental risk screening analysis, 
the 40 soil concentration points are averaged to obtain an average soil 
concentration for each facility for each PB-HAP. For the water, 
sediment, and fish tissue concentrations, the highest value for each 
facility for each pollutant is used. If emission concentrations from a 
facility do not exceed the Tier 2 screening level, the facility passes 
the screen, and typically is not evaluated further. If emissions from a 
facility exceed the Tier 2 screening level, the facility does not pass 
the screen and, therefore, may have the potential to cause adverse 
environmental effects. Such facilities are evaluated further to 
investigate factors such as the magnitude and characteristics of the 
area of exceedance.
g. Acid Gas Methodology
    The environmental screening analysis evaluates the potential 
phytotoxicity and reduced productivity of plants due to chronic 
exposure to acid gases. The environmental risk screening methodology 
for acid gases is a single-tier screen that compares the average off-
site ambient air concentration over the modeling domain to ecological 
benchmarks for each of the acid gases. Because air concentrations are 
compared directly to the ecological benchmarks, emission-based 
screening levels are not calculated for acid gases as they are in the 
ecological risk screening methodology for PB-HAPs.
    For purposes of ecological risk screening, the EPA identifies a 
potential for adverse environmental effects to plant communities from 
exposure to acid gases when the average concentration of the HAP around 
a facility exceeds the LOAEL ecological benchmark. In such cases, we 
further investigate factors such as the magnitude and characteristics 
of the area of exceedance (e.g., land use of exceedance area, size of 
exceedance area) to determine if there is an adverse environmental 
effect. For further information on the environmental screening analysis 
approach, see the Residual Risk Assessment for Pulp Mill Combustion 
Sources in Support of the December 2016 Risk and Technology Review 
Proposed Rule, which is available in the docket for this action.
6. How did we conduct facility-wide assessments?
    To put the source category risks in context, we typically examine 
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, we examine the HAP emissions not only from the 
source category emission points of interest, but also emissions of HAPs 
from all other emission sources at the facility for which we have data. 
There are currently 108 major sources subject to the 40 CFR part 63, 
subpart MM source category which includes chemical recovery combustion 
sources (e.g., recovery furnace, SDT, lime kiln). Nearly all major 
sources also have boilers on site. These facilities engage in chemical 
or mechanical pulping, papermaking, paper coating, landfills, petroleum 
storage and transfer, and other operations. Therefore, where data were 
available, we performed a facility-wide risk assessment for these major 
sources as part of this action. For this source category, we conducted 
the facility-wide assessment using the data from Part II of the Pulp 
and Paper Sector ICR.
    We analyzed risks due to the inhalation of HAPs 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 the source category 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 document titled 
Residual Risk Assessment for Pulp Mill Combustion Sources in Support of 
the December 2016 Risk and Technology Review

[[Page 97061]]

Proposed Rule, available in the docket for this action, provides the 
methodology and results of the facility-wide analyses, including all 
facility-wide risks and the percentage of source category contribution 
to facility-wide risks.
7. How did we consider uncertainties in risk assessment?
    In the Benzene NESHAP, the Agency concluded that risk estimation 
uncertainty should be considered in our decision-making under the ample 
margin of safety framework. Uncertainty and the potential for bias are 
inherent in all risk assessments, including those performed for this 
proposal. Although uncertainty exists, we believe that our approach, 
which used conservative tools and assumptions, ensures that our 
decisions are health-protective and environmentally protective. A brief 
discussion of the uncertainties in the RTR emissions dataset, 
dispersion modeling, inhalation exposure estimates, and dose-response 
relationships follows below. Where relevant to the estimated exposures, 
the lack of short-term dose-response values at different levels of 
severity should be factored into the risk characterization as potential 
uncertainties. A more thorough discussion of these uncertainties is 
included in the document titled Residual Risk Assessment for Pulp Mill 
Combustion Sources in Support of the December 2016 Risk and Technology 
Review Proposed Rule, which is available in the docket for this action.
a. Uncertainties in the RTR Emissions Dataset
    Although the development of the RTR emissions dataset involved 
quality assurance/quality control processes, various uncertainties 
exist. Thus, the accuracy of emissions values will vary depending on 
the source of the data, the degree to which data are incomplete or 
missing, the degree to which assumptions made to complete the datasets 
are accurate, errors in emission estimates, and other factors. The 
emission estimates considered in this analysis generally are annual 
totals for certain years, and they do not reflect short-term 
fluctuations during the course of a year or variations from year to 
year. The estimates of peak hourly emission rates for the acute effects 
screening assessment were based on an emission adjustment factor 
applied to the average annual hourly emission rates, which are intended 
to account for emission fluctuations due to normal facility operations.
b. Uncertainties in Dispersion Modeling
    We recognize there is uncertainty in ambient concentration 
estimates associated with any model, including the EPA's recommended 
regulatory dispersion model, AERMOD. In using a model to estimate 
ambient pollutant concentrations, the user chooses certain options to 
apply. For RTR assessments, we select some model options that have the 
potential to overestimate ambient air concentrations (e.g., not 
including plume depletion or pollutant transformation). We select other 
model options that have the potential to underestimate ambient impacts 
(e.g., not including building downwash). Other options that we select 
have the potential to either under- or overestimate ambient levels 
(e.g., meteorology and receptor locations). On balance, considering the 
directional nature of the uncertainties commonly present in ambient 
concentrations estimated by dispersion models, the approach we apply in 
the RTR assessments should yield unbiased estimates of ambient HAP 
concentrations.
c. Uncertainties in Inhalation Exposure
    The EPA did not include the effects of human mobility on exposures 
in the assessment. Specifically, short-term mobility and long-term 
mobility between census blocks in the modeling domain were not 
considered.\24\ The approach of not considering short or long-term 
population mobility does not bias the estimate of the theoretical MIR 
(by definition), nor does it affect the estimate of cancer incidence 
because the total population number remains the same. It does, however, 
affect the shape of the distribution of individual risks across the 
affected population, shifting it toward higher estimated individual 
risks at the upper end and reducing the number of people estimated to 
be at lower risks, thereby increasing the estimated number of people at 
specific high risk levels (e.g., 1-in-10 thousand or 100-in-1 million).
---------------------------------------------------------------------------

    \24\ Short-term mobility is movement from one micro-environment 
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.
---------------------------------------------------------------------------

    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 farther 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 impact, but is an unbiased estimate 
of average risk and incidence. We reduce this uncertainty by analyzing 
large census blocks near facilities using aerial imagery and adjusting 
the location of the block centroid to better represent the population 
in the block, as well as adding additional receptor locations where the 
block population is not well represented by a single location.
    The assessment evaluates 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 emission 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 
domestic facilities) will influence the future risks posed by a given 
source or source category. Depending on the characteristics of the 
industry, these factors will, in most cases, result in an overestimate 
both in individual risk levels and in the total estimated number of 
cancer cases. However, in the unlikely scenario where a facility 
maintains, or even increases, its emissions levels over a period of 
more than 70 years, residents live beyond 70 years at the same 
location, and the residents spend most of their days at that location, 
then the cancer inhalation risks could potentially be underestimated. 
However, annual cancer incidence estimates from exposures to emissions 
from these sources would not be affected by the length of time an 
emissions source operates.
    The exposure estimates used in these analyses assume chronic 
exposures to ambient (outdoor) 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 of the HAPs, indoor levels are roughly equivalent to 
ambient levels, but for very reactive pollutants or larger particles, 
indoor levels are typically lower. This factor has the potential to 
result in an overestimate of 25 to 30 percent of exposures.\25\
---------------------------------------------------------------------------

    \25\ 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

[[Page 97062]]

assessment that the EPA conducts as part of the risk review under 
section 112 of the CAA 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 the present of humans at the location 
of the maximum concentration. In the acute screening assessment that we 
conduct under the RTR program, we assume that peak emissions from the 
source category and worst-case meteorological conditions co-occur, 
thus, resulting in maximum ambient concentrations. These two events are 
unlikely to occur at the same time, making these assumptions 
conservative. We then include the additional assumption that a person 
is located at this point during this same time period. For this source 
category, these assumptions would tend to be worst-case actual 
exposures, as it is unlikely that a person would be located at the 
point of maximum exposure during the time when peak emissions and 
worst-case meteorological conditions occur simultaneously.
d. Uncertainties in Dose-Response Relationships
    There are uncertainties inherent in the development of the dose-
response 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 the 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's 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 variability in dose-response relationships is given 
in the Residual Risk Assessment for Pulp Mill Combustion Sources in 
Support of the December 2016 Risk and Technology Review Proposed Rule, 
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).\26\ In some circumstances, the true risk could be as 
low as zero; however, in other circumstances the risk could be 
greater.\27\ 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, the 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).
---------------------------------------------------------------------------

    \26\ IRIS glossary (https://iaspub.epa.gov/sor_internet/registry/termreg/searchandretrieve/glossariesandkeywordlists/search.do?details=&vocabName=IRIS%20Glossary).
    \27\ 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 RfC and reference dose (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 a continuous 
inhalation exposure (i.e., the RfC) or a daily oral exposure (i.e., the 
RfD) 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 and 1994) which considers uncertainty, 
variability and gaps in the available data. The UFs are applied to 
derive reference values that are intended to protect against 
appreciable risk of deleterious effects. The UFs are commonly default 
values,\28\ e.g., factors of 10 or 3, used in the absence of compound-
specific data; where data are available, UFs may also be developed 
using compound-specific information. When data are limited, more 
assumptions are needed and more UFs 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.
---------------------------------------------------------------------------

    \28\ 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 the 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 U.S. EPA, An Examination of EPA 
Risk Assessment Principles and Practices, EPA/100/B-04/001, 2004 
available at: https://training.fws.gov/resources/course-resources/pesticides/Risk%20Assessment/Risk%20Assessment%20Principles%20and%20Practices.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 UFs 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 (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 UFs 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. The UFs 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 UFs applied in acute 
reference value derivation include: (1) Heterogeneity among humans; (2) 
uncertainty in extrapolating from animals to humans; (3) uncertainty in 
lowest observed adverse effect (exposure) level to no observed adverse 
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

[[Page 97063]]

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 short-term dose-response values at different levels of severity 
should be factored into the risk characterization as potential 
uncertainties.
    For a group of compounds that are unspeciated (e.g., glycol 
ethers), we conservatively use the most protective reference value of 
an individual compound in that group to estimate risk. Similarly, for 
an individual compound in a group (e.g., ethylene glycol diethyl ether) 
that does not have a specified reference value, we also apply the most 
protective reference value from the other compounds in the group to 
estimate risk.
e. Uncertainties in the Multipathway Assessment
    For each source category, we generally rely on site-specific levels 
of PB-HAP emissions to determine whether a refined assessment of the 
impacts from multipathway exposures is necessary. This determination is 
based on the results of a three-tiered screening analysis that relies 
on the outputs from models that estimate environmental pollutant 
concentrations and human exposures for four PB-HAPs. Two important 
types of uncertainty associated with the use of these models in RTR 
risk assessments and inherent to any assessment that relies on 
environmental modeling are model uncertainty and input uncertainty.\29\
---------------------------------------------------------------------------

    \29\ In the context of this discussion, the term ``uncertainty'' 
as it pertains to exposure and risk encompasses both variability in 
the range of expected inputs and screening results due to existing 
spatial, temporal, and other factors, as well as uncertainty in 
being able to accurately estimate the true result.
---------------------------------------------------------------------------

    Model uncertainty concerns whether the selected models are 
appropriate for the assessment being conducted and whether they 
adequately represent the actual processes that might occur for that 
situation. An example of model uncertainty is the question of whether 
the model adequately describes the movement of a pollutant through the 
soil. This type of uncertainty is difficult to quantify. However, based 
on feedback received from previous EPA SAB reviews and other reviews, 
we are confident that the models used in the screen are appropriate and 
state-of-the-art for the multipathway risk assessments conducted in 
support of RTR.
    Input uncertainty is concerned with how accurately the models have 
been configured and parameterized for the assessment at hand. For Tier 
1 of the multipathway screen, we configured the models to avoid 
underestimating exposure and risk. This was accomplished by selecting 
upper-end values from nationally-representative datasets for the more 
influential parameters in the environmental model, including selection 
and spatial configuration of the area of interest, lake location and 
size, meteorology, surface water and soil characteristics, and 
structure of the aquatic food web. We also assume an ingestion exposure 
scenario and values for human exposure factors that represent 
reasonable maximum exposures.
    In Tier 2 of the multipathway assessment, we refine the model 
inputs to account for meteorological patterns in the vicinity of the 
facility versus using upper-end national values, and we identify the 
actual location of lakes near the facility rather than the default lake 
location that we apply in Tier 1. By refining the screening approach in 
Tier 2 to account for local geographical and meteorological data, we 
decrease the likelihood that concentrations in environmental media are 
overestimated, thereby increasing the usefulness of the screen. The 
assumptions and the associated uncertainties regarding the selected 
ingestion exposure scenario are the same for Tier 1 and Tier 2.
    For both Tiers 1 and 2 of the multipathway assessment, our approach 
to addressing model input uncertainty is generally cautious. We choose 
model inputs from the upper end of the range of possible values for the 
influential parameters used in the models, and we assume that the 
exposed individual exhibits ingestion behavior that would lead to a 
high total exposure. This approach reduces the likelihood of not 
identifying high risks for adverse impacts.
    Despite the uncertainties, when individual pollutants or facilities 
do screen out, we are confident that the potential for adverse 
multipathway impacts on human health is very low. On the other hand, 
when individual pollutants or facilities do not screen out, it does not 
mean that multipathway impacts are significant, only that we cannot 
rule out that possibility and that a refined multipathway analysis for 
the site might be necessary to obtain a more accurate risk 
characterization for the source category.
    For further information on uncertainties and the Tier 1 and 2 
screening methods, refer to the risk document, Appendix 6, Technical 
Support Document for TRIM-Based Multipathway Tiered Screening 
Methodology for RTR.
f. Uncertainties in the Environmental Risk Screening Assessment
    For each source category, we generally rely on site-specific levels 
of environmental HAP emissions to perform an environmental screening 
assessment. The environmental screening assessment is based on the 
outputs from models that estimate environmental HAP concentrations. The 
same models, specifically the TRIM.FaTE multipathway model and the 
AERMOD air dispersion model, are used to estimate environmental HAP 
concentrations for both the human multipathway screening analysis and 
for the environmental screening analysis. Therefore, both screening 
assessments have similar modeling uncertainties.
    Two important types of uncertainty associated with the use of these 
models in RTR environmental screening assessments (and inherent to any 
assessment that relies on environmental modeling) are model uncertainty 
and input uncertainty.\30\
---------------------------------------------------------------------------

    \30\ In the context of this discussion, the term 
``uncertainty,'' as it pertains to exposure and risk assessment, 
encompasses both variability in the range of expected inputs and 
screening results due to existing spatial, temporal, and other 
factors, as well as uncertainty in being able to accurately estimate 
the true result.
---------------------------------------------------------------------------

    Model uncertainty concerns whether the selected models are 
appropriate for the assessment being conducted and whether they 
adequately represent the movement and accumulation of environmental HAP 
emissions in the environment. For example, does the model adequately 
describe the movement of a pollutant through the soil? This type of 
uncertainty is difficult to quantify. However, based on feedback 
received from previous EPA SAB reviews and other reviews, we are 
confident that the models used in the screen are appropriate and state-
of-the-art for the environmental risk assessments conducted in support 
of our RTR analyses.
    Input uncertainty is concerned with how accurately the models have 
been configured and parameterized for the assessment at hand. For Tier 
1 of the environmental screen for PB-HAPs, we configured the models to 
avoid underestimating exposure and risk to reduce the likelihood that 
the results

[[Page 97064]]

indicate the risks are lower than they actually are. This was 
accomplished by selecting upper-end values from nationally-
representative datasets for the more influential parameters in the 
environmental model, including selection and spatial configuration of 
the area of interest, the location and size of any bodies of water, 
meteorology, surface water and soil characteristics, and structure of 
the aquatic food web. In Tier 1, we used the maximum facility-specific 
emissions for the PB-HAPs (other than lead compounds, which were 
evaluated by comparison to the Secondary Lead NAAQS) that were included 
in the environmental screening assessment and each of the media when 
comparing to ecological benchmarks. This is consistent with the 
conservative design of Tier 1 of the screen. In Tier 2 of the 
environmental screening analysis for PB-HAPs, we refine the model 
inputs to account for meteorological patterns in the vicinity of the 
facility versus using upper-end national values, and we identify the 
locations of water bodies near the facility location. By refining the 
screening approach in Tier 2 to account for local geographical and 
meteorological data, we decrease the likelihood that concentrations in 
environmental media are overestimated, thereby increasing the 
usefulness of the screen. To better represent widespread impacts, the 
modeled soil concentrations are averaged in Tier 2 to obtain one 
average soil concentration value for each facility and for each PB-HAP. 
For PB-HAP concentrations in water, sediment, and fish tissue, the 
highest value for each facility for each pollutant is used.
    For the environmental screening assessment for acid gases, we 
employ a single-tiered approach. We use the modeled air concentrations 
and compare those with ecological benchmarks.
    For both Tiers 1 and 2 of the environmental screening assessment, 
our approach to addressing model input uncertainty is generally 
cautious. We choose model inputs from the upper end of the range of 
possible values for the influential parameters used in the models, and 
we assume that the exposed individual exhibits ingestion behavior that 
would lead to a high total exposure. This approach reduces the 
likelihood of not identifying potential risks for adverse environmental 
impacts.
    Uncertainty also exists in the ecological benchmarks for the 
environmental risk screening analysis. We established a hierarchy of 
preferred benchmark sources to allow selection of benchmarks for each 
environmental HAP at each ecological assessment endpoint. In general, 
EPA benchmarks used at a programmatic level (e.g., Office of Water, 
Superfund Program) were used if available. If unavailable, we used EPA 
benchmarks used in regional programs (e.g., Superfund Program). If 
benchmarks were not available at a programmatic or regional level, we 
used benchmarks developed by other agencies (e.g., NOAA) or by state 
agencies.
    In all cases (except for lead compounds, which were evaluated 
through a comparison to the NAAQS), we searched for benchmarks at the 
following three effect levels, as described in section III.A.5 of this 
preamble:
    1. A no-effect level (i.e., NOAEL).
    2. Threshold-effect level (i.e., LOAEL).
    3. Probable effect level (i.e., PEL).
    For some ecological assessment endpoint/environmental HAP 
combinations, we could identify benchmarks for all three effect levels, 
but for most, we could not. In one case, where different agencies 
derived significantly different numbers to represent a threshold for 
effect, we included both. In several cases, only a single benchmark was 
available. In cases where multiple effect levels were available for a 
particular PB-HAP and assessment endpoint, we used all of the available 
effect levels to help us to determine whether risk exists and if the 
risks could be considered significant and widespread.
    The EPA evaluates the following seven HAPs in the environmental 
risk screening assessment: cadmium, dioxins/furans, POM, mercury (both 
inorganic mercury and methyl mercury), lead compounds, HCl, and HF, 
where applicable. These seven HAPs represent pollutants that can cause 
adverse impacts for plants and animals either through direct exposure 
to HAPs in the air or through exposure to HAPs that is deposited from 
the air onto soils and surface waters. These seven HAPs also represent 
those HAPs for which we can conduct a meaningful environmental risk 
screening assessment. For other HAPs not included in our screening 
assessment, the model has not been parameterized such that it can be 
used for that purpose. In some cases, depending on the HAP, we may not 
have appropriate multipathway models that allow us to predict the 
concentration of that pollutant. The EPA acknowledges that other HAPs 
beyond the seven HAPs that we are evaluating may have the potential to 
cause adverse environmental effects and, therefore, the EPA may 
evaluate other relevant HAPs in the future, as modeling science and 
resources allow.
    Further information on uncertainties and the Tier 1 and 2 
environmental screening methods is provided in Appendix 6 of the 
document, Technical Support Document for TRIM-Based Multipathway Tiered 
Screening Methodology for RTR. Also, see the document titled Residual 
Risk Assessment for Pulp Mill Combustion Sources in Support of the 
December 2016 Risk and Technology Review Proposed Rule, available in 
the docket for this action.
B. How did we consider the risk results in making decisions for this 
proposal?
    As discussed in section II.A of this preamble, in evaluating and 
developing standards under CAA section 112(f)(2), we apply a two-step 
process to address residual risk. In the first step, the EPA determines 
whether 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) 
\31\ of approximately [1-in-10 thousand] [i.e., 100-in-1 million].'' 54 
FR 38045, September 14, 1989. If risks are unacceptable, the EPA must 
determine the emissions standards necessary to bring risks to an 
acceptable level without considering costs. In the second step of the 
process, the EPA considers whether the emissions standards provide 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 feasibility, and 
other factors relevant to each particular decision.'' Id. The EPA must 
promulgate emission standards necessary to provide an ample margin of 
safety. After conducting the ample margin of safety analysis, we 
consider whether a more stringent standard is necessary to prevent, 
taking into consideration, costs, energy, safety, and other relevant 
factors, an adverse environmental effect.
---------------------------------------------------------------------------

    \31\ 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 
ofa pollutant for a lifetime.
---------------------------------------------------------------------------

    In past residual risk actions, the EPA considered a number of human 
health risk metrics associated with emissions from the categories under 
review, including the MIR, the number of persons in various risk 
ranges, cancer incidence, the maximum non-cancer HI and the maximum 
acute non-cancer hazard. See, e.g., 72 FR 25138, May 3,

[[Page 97065]]

2007; and 71 FR 42724, July 27, 2006. The EPA considered this health 
information for both actual and allowable emissions. See, e.g., 75 FR 
65068, October 21, 2010; 75 FR 80220, December 21, 2010; 76 FR 29032, 
May 19, 2011. The EPA also discussed risk estimation uncertainties and 
considered the uncertainties in the determination of acceptable risk 
and ample margin of safety in these past actions. The EPA considered 
this same type of information in support of this action.
    The Agency is considering these various measures of health 
information to inform our determinations of risk acceptability and 
ample margin of safety under CAA section 112(f). 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 [previous] section 112 is 
best judged on the basis of a broad set of health risk measures and 
information.'' 54 FR 38046, September 14, 1989. Similarly, with regard 
to the ample margin of safety determination, ``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 Benzene NESHAP approach provides flexibility regarding factors 
the EPA may consider in making determinations and how the EPA may weigh 
those factors for each source category. In responding to comment on our 
policy under the Benzene NESHAP, the EPA explained that:

    ``[t]he 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'.''

See 54 FR at 38057, September 14, 1989. Thus, the level of the MIR is 
only one factor to be weighed in determining acceptability of risks. 
The Benzene NESHAP explained that ``an MIR of approximately one 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 EPA stated in the Benzene NESHAP 
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. We also consider the uncertainties associated with the various 
risk analyses, as discussed earlier in this preamble, in our 
determinations of acceptability and ample margin of safety.
    The EPA notes that it has not considered certain health information 
to date in making residual risk determinations. At this time, we do not 
attempt to quantify those HAP risks that may be associated with 
emissions from other facilities that do not include the source 
categories in question, mobile source emissions, natural source 
emissions, persistent environmental pollution, or atmospheric 
transformation in the vicinity of the sources in these categories.
    The Agency understands the potential importance of considering an 
individual's total exposure to HAPs in addition to considering exposure 
to HAP emissions from the source category and facility. We recognize 
that such consideration may be particularly important when assessing 
non-cancer risks, where pollutant-specific exposure health reference 
levels (e.g., RfCs) 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 SAB advised 
the EPA ``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.'' \32\
---------------------------------------------------------------------------

    \32\ The EPA's responses to this and all other key 
recomendations 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 memorandum to this rulemaking 
docket from David Guinnup titled, EPA's Actions in Response to the 
Key Recommendations of the SAB Review of RTR Risk Assessment 
Methodologies.
---------------------------------------------------------------------------

    In response to the SAB recommendations, the EPA is incorporating 
cumulative risk analyses into its RTR risk assessments, including those 
reflected in this proposal. The Agency is: (1) Conducting facility-wide 
assessments, which include source category emission points as well as 
other emission points within the facilities; (2) considering sources in 
the same category whose emissions result in exposures to the same 
individuals; and (3) for some persistent and bioaccumlative pollutants, 
analyzing the ingestion route of exposure. In addition, the RTR risk 
assessments have always considered aggregate cancer risk from all 
carcinogens and aggregate non-cancer HI from all non-carcinogens 
affecting the same target organ system.
    Although 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. Because of the contribution to total HAP 
risk from emission sources other than those that we have studied in 
depth during this RTR review, such estimates of total HAP risks would 
have significantly greater associated uncertainties than the source 
category or facility-wide estimates. Such aggregate or cumulative 
assessments would compound those uncertainties, making the assessments 
too unreliable.
C. How did we perform the technology review?
    Our technology review focused on the identification and evaluation 
of developments in practices, processes, and control technologies that 
have occurred since the MACT standards were promulgated. Where we 
identified such developments, in order to inform

[[Page 97066]]

our decision of whether it is ``necessary'' to revise the emissions 
standards, we analyzed the technical feasibility of applying these 
developments and the estimated costs, energy implications, non-air 
environmental impacts, as well as considering the emission reductions. 
We also considered the appropriateness of applying controls to new 
sources versus retrofitting existing sources.
    Based on our analyses of the available data and information, we 
identified potential developments in practices, processes, and control 
technologies. For this exercise, a ``development'' was considered to be 
any of the following that was not considered during the development of 
the promulgated subpart MM standards that could result in significant 
additional reductions of regulated HAP emissions:
     Add-on control technology or other equipment not 
previously identified;
     Improvements in add-on control technology or other 
equipment;
     Work practices or operational procedures that were not 
previously identified;
     Process change or pollution prevention alternative that 
could be broadly applied to further reduce HAP emissions; and
     Improvements in work practices, operational procedures, 
process changes, or pollution prevention alternatives.
    In addition to reviewing the practices, processes, and control 
technologies that were considered at the time we originally developed 
the NESHAP, we reviewed a variety of data sources in our investigation 
of potential practices, processes, or controls to consider. Among the 
sources we reviewed were the practices, processes and control 
technologies considered in the NESHAP for various industries that were 
promulgated since the MACT standards being reviewed in this action. We 
requested information from facilities regarding developments in 
practices, processes or control technology through Part III of the Pulp 
and Paper Sector ICR. The ICR data provided information on the process 
and emission controls currently in use on chemical recovery combustion 
sources, and provided emissions data to assess the performance of 
current emissions controls. We reviewed continuous opacity monitoring 
data for ESP-controlled recovery furnaces and lime kilns. We also 
consulted the EPA's RBLC to determine whether it contained any 
practices, processes or control technologies for the types of processes 
covered by the 40 CFR part 63, subpart MM source category.\33\ We 
conducted a general search of the Internet for information on control 
technologies applicable to pulp mill combustion sources. We also 
reviewed information from other sources, such as state and/or local 
permitting agency databases.
---------------------------------------------------------------------------

    \33\ See the memorandum in the docket titled, Summary of RBLC 
and Other Findings to Suppport the Residual Risk and Technology 
Review of Chemical Recovery Combustion Sources NESHAP.
---------------------------------------------------------------------------

    Each of the evaluations listed above considered and reviewed the 
technologies suitable to demonstrate compliance with the requirements 
listed in 40 CFR 63.860 through 63.868 (subpart MM).\34\
---------------------------------------------------------------------------

    \34\ See the memorandum in the docket titled, Section 112(d)(6) 
Technology Review fo the NESHAP for Chemical Recovery Combustion 
Sourcces at Kraft, Soda, Sulfite, and Stand-Alone Semichemical Pulp 
Mills.
---------------------------------------------------------------------------

IV. Analytical Results and Proposed Decisions

A. What are the results of the risk assessment and analyses?

1. Inhalation Risk Assessment Results
    The inhalation risk modeling performed to estimate risks based on 
actual and allowable emissions relied primarily on emissions data from 
the ICR. The results of the chronic baseline inhalation cancer risk 
assessment indicate that, based on estimates of current actual and 
allowable emissions under 40 CFR part 63, subpart MM, the MIR posed by 
the MACT source category was 4-in-1 million. The total estimated cancer 
incidence from the MACT source category based on actual emission levels 
is 0.01 excess cancer cases per year, or 1 case every 100 years, while 
the cancer incidence for allowable emissions is 0.02 excess cancer 
cases per year, or 1 case every 50 years. Air emissions of chromium VI, 
formaldehyde, and naphthalene contributed 31 percent, 18 percent, and 
13 percent, respectively, to this cancer incidence. We estimated 
approximately 7,600 people to have cancer risks greater than or equal 
to 1-in-1 million considering actual and allowable emissions from 
subpart MM sources, refer to Table 3.

                       Table 3--Inhalation Risk Assessment Summary for Pulp Mill Combustion Sources Source Category--(Subpart MM)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                         Cancer MIR (in-1 million)                                          Population
                                 ----------------------------------------     Cancer        Population     with risk of     Max chronic     Max chronic
                                                                             incidence    with risk of 1-     10-in-1      noncancer HI    noncancer HI
                                    Based on actual   Based on allowable    (cases per     in-1 million     million or       (actuals)     (allowables)
                                       emissions           emissions           year)          or more          more
--------------------------------------------------------------------------------------------------------------------------------------------------------
Source Category.................  4 (naphthalene,     4 (naphthalene,               0.01           7,600               0          HI < 1          HI < 1
                                   acetaldehyde).      acetaldehyde).
Whole Facility..................  20 (arsenic,        ..................            0.05         440,000             280          HI = 1          HI = 1
                                   chromium VI).
--------------------------------------------------------------------------------------------------------------------------------------------------------

    We estimated the maximum modeled chronic non-cancer HI (TOSHI) 
value for the source category based on actual and allowable emissions 
to be 0.3, with acrolein emissions from lime kilns accounting for 92 
percent of the HI.
2. Acute Risk Results
    Our screening analysis for worst-case acute impacts based on actual 
emissions did not identify impacts associated with any pollutants that 
exceeded an HQ value of 1 based upon the REL. For the acute risk 
screening analysis, we calculated acute hourly multipliers based on the 
median of peak-to-mean ratio for 14 emission process groups ranging 
from 1.3 to 4.7, with emissions from the semichemical recovery process 
having the highest hourly peak emissions with a multiplier of 4.7. For 
more information on how we calculated the acute hourly multipliers, 
refer to the

[[Page 97067]]

risk document, Appendix 1, Preparation of Residual Risk Modeling Input 
File for Subpart MM dated September 30, 2014.
3. Multipathway Risk Screening Results
    Results of the worst-case Tier 1 screening analysis identified 
emissions (based on estimates of actual emissions) exceeding the PB-HAP 
emission cancer screening rates for dioxin/furans and polycyclic 
aromatic hydrocarbons (PAH) and the non-cancer screening threshold for 
mercury. For the compounds and facilities that did not screen out at 
Tier 1, we conducted a Tier 2 screen. The Tier 2 screen replaces some 
of the assumptions used in Tier 1 with site-specific data, including 
the location of fishable lakes and local precipitation, wind direction 
and speed. The Tier 2 screen continues to rely on high-end assumptions 
about consumption of local fish and locally grown or raised foods 
(adult female angler at 99th percentile consumption for fish for the 
subsistence fisherman scenario and 90th percentile consumption for 
locally grown or raised foods for the farmer scenario). For facilities 
for which the Tier 2 screening value(s) indicate a potential health 
risk to the public, we can conduct a Tier 3 multipathway screen. Tier 3 
has three individual stages: (1) Lake assessment to assess fishability 
and accessibility; (2) plume-rise calculations to estimate the 
emissions exiting the mixing layer and resulting in no ground-level 
exposures; (3) TRIMFaTE hourly screening runs using the layout for the 
farm and/or fish location that best characterizes the facility being 
modeled. We progress through Tier 3 stages until the facility's 
screening values indicate that emissions are unlikely to pose health 
risks to the public, or until all three stages are complete. A Tier 3 
screen was required for one facility that exceeded the Tier 2 screen 
for mercury. It is important to note that, even with the inclusion of 
some site-specific information in the Tier 2 and 3 analysis, the 
multipathway screening analysis is still a very conservative, health-
protective assessment (i.e., upper-bound consumption of local fish and 
locally grown and/or raised foods) and in all likelihood yields results 
that serve as an upper-bound multipathway risk associated with a 
facility.
    While the screening analysis is not designed to produce a 
quantitative risk result, the factor by which the emissions exceed the 
threshold serves as a rough gauge of the ``upper-limit'' risks we would 
expect from a facility. Thus, for example, if a facility emitted a PB-
HAP carcinogen at a level 2 times the screening threshold, we can say 
with a high degree of confidence that the actual maximum cancer risks 
will be less than 2-in-1 million. Likewise, if a facility emitted a 
noncancer PB-HAP at a level 2 times the screening threshold, the 
maximum noncancer hazard would represent an HQ less than 2. The high 
degree of confidence comes from the fact that the screens are developed 
using the very conservative (health-protective) assumptions that we 
describe above.
a. Cancer Risk Screening
    Results of the worst-case Tier 1 screening analysis indicate that 
85 of the 108 facilities with pulp mill combustion sources exceeded the 
PB-HAP emission cancer screening rates (based on estimates of actual 
emissions) for dioxin/furans and PAH. The EPA conducted a Tier 2 cancer 
screening analysis of the 85 facilities that were found to exceed the 
Tier 1 screening value. Nineteen of these facilities with subpart MM 
MACT source category sources emitted dioxin/furans and PAH above a 
cancer screening value of 1 for the subsistence fisher and farmer 
scenarios. In the Tier 2 analysis, the individual dioxin/furan congener 
emissions are all scaled based on their toxicity relative to 2,3,7,8-
tetrachlorodibenzo-p-dioxin and are reported as toxic equivalents 
(TEQs), and all PAH congener emissions are scaled based on their 
toxicity relative to benzo(a)pyrene and are reported as TEQs. The 
maximum Tier 2 cancer screening value for the subsistence fisher 
scenario and the farmer scenario for this source category was equal to 
10, which represents a maximum cancer risks that would be less than 10-
in-1 million. The EPA did not conduct further cancer screening for this 
source category and considered this result along with all the risk 
results as part of determining whether the risks are acceptable (as 
discussed in section B).
b. Non-Cancer Risk Screening
    Results of the worst-case Tier 1 screening analysis indicate that 
59 of the 108 plants sources exceeded the Tier 1 non-cancer screen 
value for mercury. The EPA conducted a Tier 2 chronic non-cancer 
screening analysis of the 59 facilities, resulting in 9 facilities 
emitting divalent mercury above the non-cancer screening value of 1 for 
the subsistence fisher scenario. The highest exceedance of the Tier 2 
non-cancer mercury screen value for pulp mill combustion sources under 
40 CFR part 63, subpart MM was equal to 5. The risk associated with 
divalent mercury is based on its ability to transform into the most 
toxic form of mercury as methyl mercury.
    The Tier 2 non-cancer screening analysis for the 9 facilities 
indicated potential risks greater than or equal to 2 but less than 5 
times the non-cancer screening level for the subsistence fisher 
scenario. More refined screening using Tier 3 was conducted for the 9 
facilities flagged in Tier 2. The Tier 3 screen examined the set of 
lakes from which the fisher might ingest fish (Stage 1). Any lakes that 
appeared to not be fishable or not publicly accessible were removed 
from the assessment, and the screening assessment was repeated. After 
we made the determination that the critical lakes were fishable, we 
analyzed plume rise data for each of the sites (Stage 2). The results 
of the Tier 3 screen (Stage 2) showed one facility with a non-cancer 
screen value of 2.
    We conducted the final screening stage of Tier 3 for this single 
facility utilizing a time-series assessment (Stage 3). In this stage, 
we conducted a new mercury run using TRIM.FaTE for each relevant lake 
that represents a risk concern based upon the Tier 3 plume-rise 
assessment. For these model runs, we started with the screening 
configuration corresponding to the lake location, but instead of the 
static meteorology and stack parameters used in previous screening 
tiers and stages, we used site-specific hourly meteorology and the 
hourly plume-rise values calculated in the Tier 3 plume-rise 
assessment. Allowing TRIM.FaTE to model chemical fate and transport 
with hour-by-hour changes in meteorology and plume rise produces a more 
accurate estimate of chemical concentrations in media of interest, as 
compared to the static values used in Tier 2 and the post-processing 
adjustments made in the Tier 3 plume-rise assessment. If the potential 
risk (estimated using this Tier 3 time-series approach) associated with 
a facility's PB-HAP emissions are lower than the screening value, we 
consider the emissions to pose no significant risk. This Tier 3 screen 
resulted in lowering the maximum exceedance of the screen value for the 
highest site from 2 to 1. Further details on the refined multipathway 
screening analysis are in Appendix 10, Attachment 1 of the risk report, 
``Residual Risk Assessment for Pulp Mill Combustion Sources in Support 
of the December 2016 Risk and Technology Review Proposed Rule''.
4. Environmental Risk Screening Results
    As described in section III.A of this document, we conducted an 
environmental risk screening assessment for the 40 CFR part 63, subpart 
MM source category for the following seven HAPs: PAH, mercury

[[Page 97068]]

(methyl mercury and mercuric chloride), cadmium, lead, dioxin/furans, 
HCl, and HF.
    In the Tier 1 screening analysis for PB-HAPs (other than lead, 
which we evaluated differently), one modeled soil parcel for one 
facility in the source category exceeded a surface soil--threshold 
level benchmark (invertebrates) for mercuric chloride by 2. There were 
no Tier 1 exceedances of any benchmarks for the other pollutants; PAH, 
cadmium and dioxins/furans. Therefore, we conducted a Tier 2 screen for 
mercuric chloride only. In the Tier 2 screen for mercuric chloride, 
none of the individual modeled concentrations for any facility in the 
source category exceeded any of the ecological benchmarks.
    For lead, we did not estimate any exceedances of the secondary lead 
NAAQS. For HCl and HF, the average modeled concentration around each 
facility (i.e., the average concentration of all off-site data points 
in the modeling domain) did not exceed any ecological benchmark. In 
addition, each individual modeled concentration of HCl and HF (i.e., 
each off-site data point in the modeling domain) was below the 
ecological benchmarks for all facilities.
5. Facility-Wide Risk Results
    Considering facility-wide emissions at the 108 plants, we estimated 
the MIR to be 20-in-1 million driven by arsenic and chromium VI 
emissions, and calculated the chronic non-cancer TOSHI value to be 1 
driven by emissions of acrolein (refer to Table 3). The above cancer 
and non-cancer risks are driven by emissions from the industrial 
boilers.
    We estimated approximately 440,000 people to have cancer risks 
greater than or equal to 1-in-1 million considering whole facility 
emissions from 81 of the 108 facilities modeled from the pulp and paper 
production industry (refer to Table 3). From these 81, 2 facilities 
have cancer risks greater than or equal to 10-in-1 million (but less 
than 20-in-1 million) with approximately 300 being exposed at these 
levels.
6. What demographic groups might benefit from this regulation?
    To determine whether or not to conduct a demographics analysis, 
which is an assessment of risks to individual demographic groups, we 
look at a combination of factors, including the MIR, non-cancer TOSHI, 
population around the facilities in the source category, and other 
relevant factors. For the 40 CFR part 63, subpart MM source category, 
we examined the potential for any environmental justice (EJ) issues 
that might be associated with the source category, by performing a 
demographic analysis of the population close to the facilities. In this 
analysis, we evaluated the distribution of HAP-related cancer and non-
cancer risks from the subpart MM source category across different 
social, demographic, and economic groups within the populations living 
near facilities identified as having the highest risks. The methodology 
and the results of the demographic analyses are included in a technical 
report, Risk and Technology Review--Analysis of Socio-Economic Factors 
For Populations Living Near Pulp Mill Combustion Sources, available in 
the docket for this action.
    The results of the demographic analysis are summarized in Table 4 
below. These results, for various demographic groups, are based on the 
estimated risks from actual emissions levels for the population living 
within 50 km of the facilities.

                      Table 4--Subpart MM Source Category Demographic Risk Analysis Results
----------------------------------------------------------------------------------------------------------------
                                                                                    Population
                                                                                    with cancer     Population
                                                                    Nationwide      risk at or     with chronic
                                                                                   above 1-in-1    hazard index
                                                                                      million         above 1
----------------------------------------------------------------------------------------------------------------
Total Population................................................     312,861,265           7,600               0
----------------------------------------------------------------------------------------------------------------
                                                 Race by Percent
----------------------------------------------------------------------------------------------------------------
White...........................................................              72              67               0
All Other Races.................................................              28              33               0
----------------------------------------------------------------------------------------------------------------
                                                 Race by Percent
----------------------------------------------------------------------------------------------------------------
White...........................................................              72              67               0
African American................................................              13              28               0
Native American.................................................             1.1             0.4               0
Other and Multiracial...........................................              14               5               0
----------------------------------------------------------------------------------------------------------------
                                              Ethnicity by Percent
----------------------------------------------------------------------------------------------------------------
Hispanic........................................................              17               3               0
Non-Hispanic....................................................              83              97               0
----------------------------------------------------------------------------------------------------------------
                                                Income by Percent
----------------------------------------------------------------------------------------------------------------
Below Poverty Level.............................................              14              16               0
Above Poverty Level.............................................              86              84               0
----------------------------------------------------------------------------------------------------------------
                                              Education by Percent
----------------------------------------------------------------------------------------------------------------
Over age 25 and without High School Diploma.....................              15              18               0
Over age 25 and with a High School Diploma......................              85              82               0
----------------------------------------------------------------------------------------------------------------

    The results of the 40 CFR part 63, subpart MM source category 
demographic analysis indicate that emissions from the source category 
expose approximately 7,600 people to a cancer risk at or above 1-in-1 
million

[[Page 97069]]

and no one exposed to a chronic non-cancer TOSHI greater than 1. The 
specific demographic results indicate that the percentage of the 
population potentially impacted by emissions is greater than its 
corresponding national percentage for the minority population (33 
percent for the source category compared to 28 percent nationwide), the 
African American population (28 percent for the source category 
compared to 13 percent nationwide) and for the population over age 25 
without a high school diploma (18 percent for the source category 
compared to 15 percent nationwide). The proximity results (irrespective 
of risk) indicate that the population percentages for certain 
demographic categories within 5 km of source category emissions are 
greater than the corresponding national percentage for those same 
demographics. The following demographic percentages for populations 
residing within close proximity to facilities with chemical recovery 
combustion sources are higher than the corresponding nationwide 
percentage: African American, ages 65 and up, over age 25 without a 
high school diploma, and below the poverty level.
    The risks due to HAP emissions from this source category are low 
for all populations (e.g., inhalation cancer risks are less than 4-in-1 
million for all populations and non-cancer hazard indices are less than 
1). Furthermore, we do not expect this proposal to achieve significant 
reductions in HAP emissions. Section IV.C of this preamble addresses 
opportunities as part of the technology review to further reduce HAP 
emissions. These technologies were found not to be cost-effective. 
Therefore, we conclude that this proposal will not have 
disproportionately high and adverse human health or environmental 
effects on minority or low-income populations because it does not 
affect the level of protection provided to human health or the 
environment. However, this proposal, if finalized, will provide 
additional benefits to these demographic groups by improving the 
compliance, monitoring, and implementation of the NESHAP.

B. What are our proposed decisions regarding risk acceptability, ample 
margin of safety, and adverse environmental effects?

1. Risk Acceptability
    As noted in section II.A of this preamble, the EPA sets standards 
under CAA section 112(f)(2) using ``a two-step standard-setting 
approach, with an analytical first step to determine an 'acceptable 
risk' that considers all health information, including risk estimation 
uncertainty, and includes a presumptive limit on MIR of approximately 
1-in-10 thousand.'' (54 FR 38045, September 14, 1989).
    In this proposal, the EPA estimated risks based on both actual and 
allowable emissions from pulp mill combustion sources. As discussed 
above, in determining acceptability, we considered risks based on both 
actual and allowable emissions. Based on the risk assessment results 
described above, the EPA is proposing that the risks are acceptable.
    The baseline inhalation cancer risk from the source category was 4-
in-1-million for the most exposed individual based on actual and 
allowable emissions. The total estimated incidence of cancer for this 
source category due to inhalation exposures is 0.02 excess cancer cases 
per year, or 1 case in 50 years. The Agency estimates that the maximum 
chronic non-cancer TOSHI from inhalation exposure for this source 
category has an HI equal to 0.3 based upon both actual and allowable 
emissions. Lime kilns account for a large portion (92 percent) of the 
HI.
    The multipathway screening analysis, based upon actual emissions, 
indicates the excess cancer risk from this source category is less than 
10-in-1 million based on dioxins/furans and PAH emissions, with PAH 
emissions accounting for 99 percent of these potential risks from the 
fisher and the farmer scenarios. There were no facilities within this 
source category with a multipathway non-cancer screen value greater 
than 1 for cadmium or mercury. In evaluating the potential for 
multipathway effects from emissions of lead, we compared modeled 
maximum annual lead concentrations to the secondary NAAQS for lead 
(0.15 [mu]g/m3). Results of this analysis estimate that the NAAQS for 
lead would not be exceeded at any off-site locations.
    To put the risks from the source category in context, we also 
evaluated facility-wide risk. Our facility-wide assessment, based on 
actual emissions, estimated the MIR to be 20-in-1 million driven by 
arsenic and chromium VI emissions, and estimated the chronic non-cancer 
TOSHI value to be 1 driven by emissions of acrolein. We estimated 
approximately 440,000 people to have cancer risks greater than or equal 
to 1-in-1 million considering facility-wide emissions from the pulp and 
paper production industry (see Table 3). The above cancer and non-
cancer risks are driven by emissions from industrial boilers, 
representing 62 percent of the cancer risks and 95 percent of the non-
cancer risks. Emissions from the 40 CFR part 63, subpart MM sources 
represent only 6 percent of the total facility-wide cancer risk of 20-
in-1 million.
    The screening assessment of worst-case acute inhalation impacts 
indicates no pollutants exceeding an HQ value of 1 based on the REL, 
with an estimated worst-case maximum acute HQ of 0.3 for acrolein based 
on the 1-hour REL.
    A review of the uncertainties in the risk assessment identified one 
additional key consideration, and that is the quality of data 
associated with the whole-facility emissions. The data provided from 
the power boilers were collected in 2009 and represent pre-MACT 
emissions before any controls. The uncertainty introduced by using pre-
MACT boiler emissions data may result in an overestimated risk estimate 
for the whole-facility analysis for both cancer and non-cancer impacts.
    Considering all of the available health risk information, we 
propose that risks from the source category are acceptable.
2. Ample Margin of Safety Analysis
    As directed by section 112(f)(2), we conducted an additional 
analysis to determine whether additional standards are needed to 
provide an ample margin of safety to protect public health. Under this 
ample margin of safety analysis, we evaluated the cost and feasibility 
of available control technologies and other measures that could be 
applied in this source category to further reduce the risks (or 
potential risks) due to emissions of HAPs identified in our risk 
assessment, along with all of the health risks and other health 
information considered in our determination of risk acceptability.
    Although we are proposing that the risks from the subpart MM source 
category are acceptable, inhalation risk estimates are above 1-in-1 
million at the actual and MACT-allowable emission levels for 
approximately 7,600 individuals in the exposed population. The HAP risk 
drivers contributing to the inhalation risks in excess of 1-in-1 
million include primarily the gaseous organic HAPs acetaldehyde and 
naphthalene. Additional gaseous organic HAPs contributing to the risk 
includes benzene, chloroprene, formaldehyde, 2-methylnaphthalene, 7,12-
dimethylbenz[a]anthracene, acenaphthene, acenaphthylene, and 
fluoranthene. More than 80-percent of the mass emissions of these 
compounds originate from NDCE recovery furnaces, and DCE recovery 
furnaces (including BLO systems). We considered options for further 
reducing gaseous organic HAP emissions from NDCE and DCE

[[Page 97070]]

recovery furnaces. The greatest reduction in gaseous organic HAP 
emissions that could be achieved for DCE recovery furnaces would result 
from DCE-to-NDCE furnace conversions or replacements of DCE furnaces 
with NDCE systems. We estimated furnace emissions to be reduced when a 
DCE furnace is converted (or replaced with NDCE design). Conversion or 
replacement of a DCE system with an NDCE system results in removal of 
the BLO system and elimination of 100 percent of the BLO emissions. For 
NDCE recovery furnaces with wet ESP systems, conversion of the wet ESP 
system to a dry system can further reduce gaseous organic HAPs. Section 
IV.C.1 of this preamble discusses the costs and impacts associated with 
DCE conversions (or replacements) and wet-to-dry ESP conversions for 
NDCE recovery furnaces. The overall cost of these options is an 
estimated $1.4 billion to $3.7 billion in capital cost and $120 million 
to $440 million in annualized cost. Application of this option would 
achieve an estimated emission reduction of 2,920 tpy of gaseous organic 
HAPs (including risk drivers and other gaseous organic HAPs), and the 
corresponding cost-effectiveness ranges from $45,000 to $153,000 per 
ton of emissions reduced. The non-air environmental impacts, energy 
impacts, and secondary air emissions associated with the options 
described above are discussed in a memorandum in the docket. Due to the 
low level of current risk and the substantial costs associated with 
these options, we are proposing that additional emission reductions 
from the source category are not necessary to provide an ample margin 
of safety.
3. Adverse Environmental Effects
    Based on the results of our environmental risk screening 
assessment, we propose to conclude that there is not an adverse 
environmental effect as a result of HAP emissions from the 40 CFR part 
63, subpart MM source category.\35\ Thus, we are proposing that it is 
not necessary to set a more stringent standard to prevent an adverse 
environmental effect.
---------------------------------------------------------------------------

    \35\ The environmental screening analysis is documented in 
Residual Risk Assessment for Pulp Mill Combustion Sources in Support 
of the December 2016 Risk and Technology Review Proposed Rule, in 
the docket for this action.
---------------------------------------------------------------------------

C. What are the results and proposed decisions based on our technology 
review?

1. Kraft and Soda Recovery Furnaces
    The ability to recover pulping chemicals is imperative to the kraft 
and soda process, and is achieved by burning spent pulping liquor 
(i.e., black liquor) in a recovery furnace. The recovery furnace is 
easily identified at a pulp mill because it is typically the tallest 
equipment on site. The purpose of the recovery furnace is to: (1) 
Recover inorganic pulping chemicals (e.g., sodium sulfide 
(Na2S) and sodium hydroxide (NaOH) in kraft mills and NaOH 
in soda mills); and (2) produce steam. The recovered inorganic pulping 
chemicals are reused in the process, and the steam is used to generate 
electricity and for process heating. Prior to being fired in the 
recovery furnace, black liquor recovered from pulp washing is 
concentrated using an NDCE or DCE. The NDCE is an indirect, steam-
heated black liquor concentrator. The DCE uses the hot combustion gases 
exiting the furnace to increase the solids content of the black liquor. 
A BLO system precedes the DCE to reduce malodorous total reduced sulfur 
(TRS) emissions that can be stripped in the DCE when hot flue gases 
from the recovery furnace come in contact with the black liquor. The 
BLO system uses molecular oxygen (O2) or air to oxidize 
Na2S to nonvolatile sodium thiosulfate 
(Na2S2O3) to reduce the potential for 
stripping. Outputs from recovery furnaces include molten smelt 
(primarily Na2S and sodium carbonate 
(Na2CO3)), flue gases, and steam. The smelt exits 
from the bottom of the furnace into an SDT, where the recovery of kraft 
pulping chemicals continues. Particulate matter (primarily sodium 
sulfate (Na2SO4) [salt cake] and 
Na2CO3) entrained in the flue gases is also 
recovered using an ESP, which deposits the collected material into a 
chemical ash tank or salt cake mix tank for subsequent addition into 
the concentrated black liquor.
    We reviewed ICR data on recovery furnace design and emissions 
controls for purposes of the technology review. There are currently 148 
kraft and soda recovery furnaces in the United States, including 36 
existing DCE furnaces, 108 existing NDCE furnaces, and 4 recovery 
furnaces subject to the new source limits under 40 CFR part 63, subpart 
MM. The vast majority (96 percent) of recovery furnaces have ESP 
control, including the 4 NDCE recovery furnaces subject to the new 
source limits under subpart MM. Three of the DCE furnaces and one of 
the NDCE furnaces have an ESP followed by a wet scrubber. Two NDCE 
furnaces have a wet scrubber alone. The one remaining soda recovery 
furnace is a subpart MM new source with ESP control. As we noted in 
2001, when subpart MM was promulgated, we project no new DCE recovery 
furnaces to be installed in the future, because more energy-efficient 
NDCE technology is now prevalent.
    Recovery furnace ESPs can be further characterized as wet- or dry-
bottom ESPs having either a wet or dry PM return system. A wet-bottom 
ESP uses either oxidized or unoxidized black liquor to collect the PM 
and carry it to the salt cake mix tank via a wet PM return system. A 
dry-bottom ESP routes the captured PM to the mix tank via a screw 
conveyor or drag chain without the use of liquid, typically with a dry 
PM return system. However, there are some dry-bottom ESPs with a wet PM 
return system that use black liquor or other process liquids to 
transport the dry collected PM to the mix tank. Approximately 60 
percent of recovery furnaces in the United States (or 90 recovery 
furnaces) have a dry-bottom ESP with a dry PM return system (including 
two furnaces with a dry-bottom ESP followed by a scrubber).
    Recovery furnace gaseous organic HAP. Subpart MM of 40 CFR part 63 
contains a gaseous organic HAP limit of 0.025 lb/ton BLS (measured as 
methanol) for new recovery furnaces based on use of an NDCE recovery 
furnace with a dry-bottom ESP and a dry PM return system. Recovery 
furnace system design impacts gaseous organic HAP emissions. Non-direct 
contact evaporator recovery furnaces emit less gaseous organic HAPs 
because there is no contact between the incoming black liquor and hot 
flue gases in the evaporator and there is no BLO system. Replacement of 
DCE recovery furnace systems with a new NDCE recovery furnace or 
conversion of an existing DCE furnace to an NDCE design (referred to as 
a ``low-odor conversion''), along with removal of the associated BLO 
system, provides the greatest reduction in gaseous organic HAP 
emissions. Use of a dry-bottom ESP system with a dry PM return also 
reduces gaseous organic HAP emissions.
    Analysis of ICR data for our technology review revealed that the 
number of DCE recovery furnaces in the United States continues to 
decrease as facilities with older DCE furnaces either close or, where 
feasible, replace aging DCE furnaces or convert them to NDCE systems. 
When subpart MM was proposed in 1998, 39 percent of recovery furnaces 
(82 units) were DCE systems. Today, only 36 DCE recovery furnaces 
remain, which is 24 percent of

[[Page 97071]]

the recovery furnace population (including 2 DCE recovery furnaces that 
are only used as backup systems for times when other NDCE furnaces 
onsite are not operating).
    We analyzed the costs and environmental impacts of replacement or 
conversion of the remaining DCE recovery furnaces as part of our 
technology review. High capital costs of an estimated $1.3 to $3.7 
billion and annualized costs of an estimated $120 to $440 million are 
associated with recovery furnace installation (or conversion) projects 
due to the integral nature of the recovery furnace within the pulp mill 
and the number of upstream and downstream equipment components that 
must be removed, replaced, or reengineered along with the recovery 
furnace itself. These costs would be borne by 21 facilities that 
continue to operate DCE recovery furnaces and are not already projected 
to replace these systems in the absence of any regulatory action. The 
cost effectiveness of recovery furnace conversions or replacements is 
also high, at an estimated $44,000 to $159,000 per ton of gaseous 
organic HAPs reduced. We estimated a range of costs based on multiple 
information sources.
    We also considered the costs and impacts associated with converting 
the remaining NDCE recovery furnace wet-bottom ESPs in the industry to 
dry-bottom ESPs. Capital costs are an estimated $56.1 million for wet-
to-dry bottom ESP conversions at 11 mills with NDCE recovery furnaces, 
with cost effectiveness of $54,000 per ton of gaseous organic HAPs 
removed.
    The total costs of the gaseous organic HAP options we considered 
are an estimated $1.4 to $3.7 billion in capital cost borne by 32 
facilities, to achieve an estimated emission reduction of 2,920 tpy of 
gaseous organic HAP at a cost effectiveness of $45,000 to $153,000 per 
ton of gaseous organic HAPs removed. Collateral TRS emission reductions 
are an estimated 1,250 tpy at a cost effectiveness of $104,000 to 
$357,000 per ton of TRS reduced. Given the high capital costs and high 
cost per ton of emissions reduced, we are not proposing additional 
regulation of recovery furnace gaseous organic HAP emissions as a 
result of the technology review.
    Recovery furnace PM. Under the current 40 CFR part 63, subpart MM, 
PM is a surrogate for HAP metal emissions. Subpart MM requires existing 
recovery furnaces to meet a PM emission limit of 0.044 grains per dry 
standard cubic foot (gr/dscf) at 8 percent O2 and requires 
new recovery furnaces to meet a PM limit of 0.015 gr/dscf at 8-percent 
O2. We recently analyzed PM emissions test data collected 
with the 2011 Pulp and Paper Sector ICR for purposes of the Kraft Pulp 
Mill NSPS review promulgated on April 4, 2014 (79 FR 18952). We 
reviewed the PM data tabulated for the NSPS review in the context of 
the existing and new source PM limits for the subpart MM NESHAP 
technology review. The dataset included more than 200 filterable PM 
stack tests, including some repeat tests, on nearly all of the recovery 
furnaces in the United States using a variety of PM emission controls 
(ESP, ESP and wet scrubber combinations, and wet scrubbers). The PM 
stack test data revealed little or no distinction between DCE and NDCE 
recovery furnaces for PM emissions. Nearly all of the recovery furnaces 
tested met the current existing source limit (0.044 gr/dscf),\36\ and 
several met the new source limit (0.015 gr/dscf), though there was a 
considerable scatter of emission test results between 0.015 and 0.044 
gr/dscf, including variability in test results for the same units 
tested multiple times. There was also variability in the performance of 
the different types of ESP or ESP and scrubber systems such that no one 
type of control system seemed to perform better than another. Based on 
the data, wet scrubbing of recovery furnace exhaust gases (either alone 
or in conjunction with an ESP) does not necessarily improve filterable 
PM removal. After reviewing the recovery furnace PM emissions data, we 
concluded that the current subpart MM emission limits of 0.044 gr/dscf 
and 0.015 gr/dscf continue to represent the performance of existing and 
new recovery furnaces, respectively. The technology review did not 
reveal any developments in practices, processes, and control 
technologies for reducing PM emissions from recovery furnaces that have 
occurred since promulgation of subpart MM. Therefore, we are not 
proposing any changes to the PM emission limits for purposes of the 
technology review. As discussed below, we estimated incidental 
incremental improvements in PM emissions as part of our analysis of the 
opacity monitoring limit for recovery furnaces.
---------------------------------------------------------------------------

    \36\ Exceptions included a few stack tests that were repeated, 
or recovery furnaces that participate in the PM bubble compliance 
option under 40 CFR part 63, subpart MM.
---------------------------------------------------------------------------

2. Kraft and Soda Lime Kilns
    In kraft and soda pulp mills, the lime kiln is part of the 
causticizing process in which green liquor from the SDT is converted to 
white liquor. The function of the lime kiln is to oxidize lime mud 
(calcium carbonate, CaCO3) to reburned lime (calcium oxide, 
CaO) in a process known as calcining. Lime kiln air pollution control 
devices include wet scrubbers, ESPs, or a combination system including 
an ESP followed by a wet scrubber. The 2011 ICR data indicate that, of 
130 lime kilns in the United States, 89 kilns have wet scrubbers, 30 
kilns have ESPs, and 11 kilns have ESP-wet scrubber combinations.
    Subpart MM, 40 CFR part 63, includes a PM limit of 0.064 gr/dscf at 
10-percent O2 (which is a surrogate limit for HAP metals) 
for existing lime kilns. For new or reconstructed lime kilns, the 
subpart MM limit is 0.010 gr/dscf at 10-percent O2 based on 
use of a high-efficiency ESP. Subpart MM does not distinguish between 
fuel types. Lime kilns typically burn natural gas, fuel oil, petroleum 
coke, or a combination of these fuels. They may also burn 
noncondensable gases (NCGs) or pulp mill byproducts such as tall oil.
    The EPA recently reviewed PM stack test data from more than 250 
filterable PM stack tests (including several repeat tests) on 110 lime 
kilns in the United States for purposes of the Kraft Pulp Mill NSPS 
review. The EPA interpreted this same dataset in the context of 
conducting the technology review of the subpart MM PM limits for lime 
kilns. The tests included lime kilns with scrubbers, ESPs and ESP-wet 
scrubber combination controls. Most of the scrubber-controlled kilns 
achieved the subpart MM existing source limit (0.064 gr/dscf at 10-
percent O2) with the exception of kilns that participate in 
the PM bubble compliance alternative. The data suggested that scrubber-
controlled kilns would not be expected to meet the subpart MM new 
source limit of 0.010 gr/dscf at 10-percent O2. The EPA 
found that ESP and ESP-wet scrubber controls typically reduce PM to 
lower levels than wet scrubbers alone. The ESP-wet scrubber systems did 
not necessarily perform better on filterable PM than the ESPs alone. 
Several existing ESP and ESP-wet scrubber controlled kilns consistently 
met the 0.064 gr/dscf existing source limit, and often met the new 
source limit of 0.010 gr/dscf at 10-percent O2. The EPA 
observed test results between the existing and new source limit for 
existing sources with ESP and ESP-wet scrubber systems. Our review of 
the PM emissions test data for lime kilns suggests that the subpart MM 
limits for lime kilns are appropriate. For purposes of the subpart MM 
technology review, the EPA has identified no practices, processes, or 
controls for PM emissions from lime kilns beyond those

[[Page 97072]]

identified when subpart MM was developed. Therefore, the EPA is not 
proposing any changes to the existing PM limits of 0.064 gr/dscf at 10-
percent O2 for existing lime kilns and 0.010 gr/dscf at 10-
percent O2 for new and reconstructed lime kilns.
3. Recovery Furnace and Lime Kiln Monitoring
    This subsection discusses our review of the opacity and ESP 
monitoring provisions for recovery furnaces and lime kilns with ESPs or 
combined ESP and wet scrubber systems.
    Continuous opacity monitoring. Subpart MM of 40 CFR part 63 
requires continuous monitoring of opacity to demonstrate ongoing 
compliance with the PM concentration limits for ESP-controlled recovery 
furnaces and lime kilns. The current PM opacity limits under subpart MM 
are 35-percent opacity for existing recovery furnaces and 20-percent 
opacity for existing lime kilns, new lime kilns, and new recovery 
furnaces. Subpart MM contains an opacity monitoring allowance for 
existing sources where 6 percent of the 6-minute opacity averages 
during a quarter (excluding periods of SSM and periods when the 
facility is not operating) may exceed the 35-percent recovery furnace 
or 20-percent lime kiln opacity limit without being considered a 
violation. Subpart MM currently contains a corrective action threshold 
of 10 consecutive 6-minute averages above 20-percent opacity for new 
and existing recovery furnaces and lime kilns.
    The EPA reviewed recovery furnace and lime kiln continuous opacity 
monitoring system (COMS) data for purposes of the technology review to 
evaluate the current 40 CFR part 63, subpart MM opacity limits and 6-
percent monitoring allowance. The EPA performed a similar review of the 
COMS data for the subpart BBa NSPS review promulgated April 4, 2014 (79 
FR 18952). The EPA's analysis of the recovery furnace COMS data for 
subpart MM is included in a memorandum in the docket.\37\ Our 
conclusions from reviewing the opacity data in the context of subpart 
MM are consistent with the conclusions reached for the 2014 NSPS 
review.
---------------------------------------------------------------------------

    \37\ See memorandum titled, Review of the Continuous Opacity 
Monitoring Data from the Pulp and Paper ICR Responses for Subpart MM 
Sources, in the docket.
---------------------------------------------------------------------------

    The COMS data for 135 recovery furnaces show that the majority of 
existing recovery furnaces, regardless of design (DCE or NDCE), and 
with most controls, are meeting a 20-percent opacity limit based on a 
6-minute average, with fewer than 2 percent of averaging periods 
exceeding 20-percent opacity, including periods of startup and 
shutdown. The EPA also reviewed state permits and found many recovery 
furnaces with permit limits of 20-percent opacity. Therefore, the EPA 
concludes that this information is evidence that there has been a 
development in existing recovery furnace operating practices that 
supports reducing the existing source opacity limit from 35-percent to 
20-percent and revising the monitoring allowance for the 20-percent 
opacity limit from 6 percent to a 2-percent monitoring allowance as 
part of the 40 CFR part 63, subpart MM technology review process.
    The COMS data for 28 ESP-controlled lime kilns show that all of the 
existing lime kilns are meeting the 20-percent opacity limit based on a 
6-minute average, with nearly all performing at a 1-percent monitoring 
allowance, including periods of startup and shutdown. The EPA considers 
this information as evidence that there has been a development in 
existing lime kiln operating practices and that this development 
supports revising the monitoring allowance from 6 percent to a 1-
percent monitoring allowance for opacity as part of the 40 CFR part 63, 
subpart MM technology review process.
    Subpart MM of 40 CFR part 63 currently requires that the opacity 
allowance be calculated based on the percent of the operating time in a 
quarter in which excess emissions are recorded. The Agency is proposing 
to change the reporting requirement frequency, as discussed in section 
IV.D.4, and, therefore, analyzed both quarterly and semiannual 
averaging periods when reviewing the proposed monitoring allowance 
discussed above.
    The EPA considered the impacts of various opacity monitoring 
options as part of the technology review. The opacity regulatory 
options considered for kraft and soda recovery furnaces were:
    Baseline Option 1: 35-percent opacity (existing) or 20-percent 
opacity (new), 20-percent corrective action level, 6-percent monitoring 
allowance, quarterly reporting.
    Option 2: 35-percent opacity, 20-percent corrective action level, 
2-percent monitoring allowance, semiannual reporting.
    Option 3: 20-percent opacity, 6-percent monitoring allowance, 
quarterly reporting.
    Option 4: 20-percent opacity, 2-percent monitoring allowance, 
semiannual reporting.
    Option 5: 20-percent opacity, 2-percent monitoring allowance, 
quarterly reporting.

The opacity regulatory options considered for kraft and soda ESP-
controlled lime kilns were:
    Baseline Option 1: 20-percent opacity and corrective action level 
with 6-percent allowance, quarterly reporting.
    Option 2: 20-percent opacity with a 1-percent monitoring allowance, 
semiannual reporting.
    Option 3: 20-percent opacity with a 1-percent monitoring allowance, 
quarterly reporting.
    For purposes of estimating costs and impacts of the regulatory 
options, we assumed that recovery furnaces and ESP-controlled lime 
kilns that did not meet the regulatory options in our COMS analysis 
would require ESP maintenance and testing to improve opacity 
performance, or an ESP upgrade. The EPA also reviewed PM performance 
levels (based on PM stack test data) for emission units not meeting the 
opacity limits under consideration in at least one reporting period. If 
the PM performance level achieved met the PM performance expected from 
an upgraded ESP (0.015 gr/dscf at 8-percent O2 for recovery 
furnaces or 0.010 gr/dscf at 10-percent O2 for lime kilns), 
then we assumed that the ESP would only require improved annual 
maintenance and testing to achieve the opacity options. Otherwise, we 
assumed that units would require an ESP upgrade to meet the opacity 
options.
    Although we are not proposing any changes to the PM metal HAP 
limits as part of the technology review, ESP upgrades to meet a tighter 
opacity monitoring limit would have the effect of reducing PM 
emissions. We estimated recovery furnace upgrade costs for adding two 
parallel fields to an existing ESP resulting in a PM performance level 
of 0.015 gr/dscf at 8-percent O2. For lime kilns, we 
estimated costs based on adding one field to the existing ESP to 
achieve a PM performance level of 0.01 gr/dscf at 10-percent 
O2. For each emission unit expected to require an ESP 
upgrade, we estimated the potential reduction in PM emissions by 
subtracting the PM limit expected to be achieved by the upgraded ESP 
from the lower of the current PM permit limit or the actual PM 
performance level for the emission unit.
    The EPA's full analysis of the cost and impacts associated with the 
regulatory options for opacity (including energy and secondary air 
impacts) is presented

[[Page 97073]]

in a memorandum in the docket.\38\ Table 5 summarizes the number of 
impacted facilities, estimated cost, PM reductions, and cost 
effectiveness of the opacity regulatory options.
---------------------------------------------------------------------------

    \38\ See memorandum titled, Costs/Impacts of the Subpart MM 
Residual Risk and Technology Review, in the docket.

                                                Table 5--Costs and Impacts of Opacity Regulatory Options
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                         2015$
                                                           --------------------------------                                                    Cost
                  Option                       Number of                      Annualized          Incremental  HAP reduction,  tpy         effectiveness
                                            mills impacted  Capital costs,      costs,                                                      $/ton PM\1\
                                                               $million       $million/yr
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                   Recovery Furnaces Opacity Monitoring Limit Options
--------------------------------------------------------------------------------------------------------------------------------------------------------
Baseline Option 1: No change. 35% opacity,               0               0               0  0...........................................              NA
 20% corrective action level (CAL), 6%
 monitoring allowance (MA), quarterly (Q)
 reporting.
Option 2: 35% opacity, 20% CAL, 2% MA,                   1               0           0.087  0...........................................              NA
 semiannual (SA) reporting.
Option 3: 20% opacity, 6% MA, Q reporting.               7              27             5.4  188 (PM), 85 (PM2.5)........................          28,400
Option 4: 20% opacity, 2% MA, SA reporting              12              42             8.7  235 (PM), 112 (PM2.5).......................          36,800
Option 5: 20% opacity, 2% MA, Q reporting.              19              74              15  364 (PM), 170 (PM2.5).......................          41,000
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                       Lime Kiln Opacity Monitoring Limit Options
--------------------------------------------------------------------------------------------------------------------------------------------------------
Option 1: No change. 20% opacity, 6% MA, Q               0               0               0  0...........................................              NA
 reporting.
Option 2: 20% opacity, 1% MA, SA reporting               2               0           0.068  0...........................................              NA
                                           -------------------------------------------------------------------------------------------------------------
Option 3: 20% opacity, 1% MA, Q reporting.                                                Same as option 2
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ HAP metals comprise less than 0.5-percent of the PM emissions (0.03-percent for recovery furnaces or 0.48-percent for lime kilns). Thus, the cost
  effectiveness specifically for HAP metals is orders of magnitude greater than that shown for PM (>$5.5 million per ton HAP metals).

    After considering the costs and impacts of the regulatory options 
for opacity, we are proposing recovery furnace option 4 and lime kiln 
option 2 for opacity monitoring. These options are representative of 
the actual performance of 40 CFR part 63, subpart MM emission units 
based on our analysis of the COMS data, and also align closely with the 
opacity limits, monitoring allowances, and semiannual reporting 
requirements established for new sources through the 2014 NSPS review. 
The EPA is proposing to reduce the opacity limit for existing recovery 
furnaces from 35-percent to 20-percent opacity. Lowering the recovery 
furnace opacity limit to 20 percent eliminates the need for the 20-
percent corrective action level. Specifying a 20-percent corrective 
action level is redundant where the opacity limit is already set at 20-
percent; therefore, we are proposing to eliminate the subpart MM 
corrective action level in 40 CFR 63.864(k)(1)(i) by reserving this 
section. We are proposing a monitoring allowance of 2-percent for 
existing and new recovery furnaces. We are proposing to retain the 20-
percent opacity limit and are proposing a monitoring allowance of 1 
percent for opacity monitoring for lime kilns. We are also proposing to 
reduce the reporting frequency from quarterly to semiannually, as 
discussed in section IV.D.4 of this preamble. The proposed semiannual 
averaging period would be used for calculating the opacity monitoring 
allowance, providing flexibility for startup and shutdown periods. The 
cost effectiveness of recovery furnace option 4, $36,800 per ton PM, is 
within the range of other recent EPA regulations. There is no cost 
effectiveness value for lime kiln option 2 because no incremental HAP 
reductions were estimated. In addition to proposing the revisions 
described above, the EPA is requesting comment on all of the options 
presented in Table 5.
    ESP parameter monitoring. The EPA is proposing to add an ESP 
parameter monitoring requirement for recovery furnaces and lime kilns 
equipped with ESPs. The purpose of this is to provide another indicator 
of ESP performance and enable affected sources to show continuous 
compliance with the HAP metal standards (surrogate PM emission limit) 
at all times, including periods when the opacity monitoring allowance 
is used. The EPA is proposing that these sources monitor the secondary 
voltage and secondary current (or, alternatively, total secondary 
power) of each ESP collection field. These ESP parameter monitoring 
requirements are in addition to opacity monitoring for recovery 
furnaces equipped with ESPs alone. The EPA is proposing that these ESP 
parameters be monitored, recorded every successive 15 minutes, and 
averaged over the same semiannual period as the opacity monitoring 
allowance. The semiannual average of the ESP parameters must remain 
above the minimum limits established during the PM performance test 
(i.e., above the minimum secondary current and secondary voltage or 
above minimum total secondary power).
    The EPA estimates that the nationwide costs associated with adding 
the proposed ESP parameter monitoring requirements would be $5.7 
million capital and $1.4 million annualized costs for ESP parameter 
monitors. All mills with ESP-controlled recovery furnaces and lime 
kilns are estimated to be impacted.
    Monitoring of ESPs followed by wet scrubbers. Because moisture in 
wet stacks interferes with opacity readings, opacity is not a suitable 
monitoring requirement for recovery furnaces or lime kilns with wet 
scrubber stacks. The EPA is therefore proposing to require ESP and wet 
scrubber parameter monitoring for emission units equipped with an ESP 
followed by a wet scrubber. The ESP parameters to be monitored are

[[Page 97074]]

secondary voltage and secondary current (or, alternatively, total 
secondary power), and the wet scrubber parameters are pressure drop and 
scrubber liquid flow rate. The EPA is proposing that ESP and wet 
scrubber parameters be recorded at least once every successive 15-
minute period and reduced to 3-hour averages. The EPA estimates no 
incremental costs to be associated specifically with the proposed 
monitoring requirements for combined ESP-wet scrubber systems because 
the ESP parameter monitoring costs estimated above include ESPs in 
combined control systems, and wet scrubber parameter monitoring is 
already required under 40 CFR part 63, subpart MM.
4. Kraft and Soda Smelt Dissolving Tanks
    Smelt dissolving tanks are covered vessels located below the 
recovery furnace to collect molten smelt, one of the main products from 
the combustion of black liquor. Smelt is comprised predominantly of 
Na2S and Na2CO3 and is formed in the 
bottom of the recovery furnace. The smelt is continuously discharged 
through water-cooled smelt spouts into the SDT where it is mixed with 
weak wash water from the pulp mill recausticizing area to form green 
liquor, an aqueous solution of Na2CO3 and 
Na2S. The green liquor is subsequently transferred to the 
recausticizing area for reprocessing into pulping liquor (i.e., white 
liquor). In the soda pulping process, the molten smelt and green liquor 
is predominantly Na2CO3 because soda pulping is a 
non-sulfur process. Based on the 2011 Pulp and Paper Sector ICR data, 
there are 161 kraft and soda SDTs in the United States. Nearly all of 
the SDTs have wet scrubbers that control the particulate emissions, 
including HAP metals, from this process. A small number of SDTs use 
mist eliminators as the only means of emissions control. Some new 
sources were designed to vent emissions through the recovery furnace as 
an alternative to using wet scrubber control alone, but also have a wet 
scrubber for backup periods when venting to the recovery furnace is not 
feasible.
    SDT PM. The current 40 CFR part 63, subpart MM PM emission limit 
(which is a surrogate for HAP metals) for existing SDTs is 0.20 lb/ton 
BLS. The subpart MM PM limit for new and reconstructed sources with 
initial startup in 2001 or later is 0.12 lb/ton BLS based on the use of 
a high-efficiency wet scrubber.
    The EPA analyzed SDT PM stack test data collected with the 2011 
Pulp and Paper Sector ICR for the NSPS review promulgated on April 4, 
2014 (79 FR 18952). We reviewed this same dataset in the context of 
subpart MM for purposes of the 40 CFR part 63, subpart MM technology 
review. The stack test data show that nearly all SDTs have achieved the 
subpart MM existing source limit of 0.20 lb/ton BLS (with the exception 
of a few SDTs with mist eliminators and SDTs included in the PM bubble 
compliance option under subpart MM). There were many existing scrubber-
controlled SDTs with emissions between the new source limit of 0.12 lb/
ton BLS and the existing source limit of 0.20 lb/ton BLS. The practice 
of routing SDT emissions through the recovery furnace has an 
unquantified effect on PM emissions because no emission test data are 
available to differentiate SDT emissions from the recovery furnace 
emissions in these systems. The EPA has identified no practices, 
processes, or controls for SDTs beyond those identified at the time of 
subpart MM development, nor any incremental improvements in the ability 
of wet scrubbers to reduce PM. Therefore, the EPA is not proposing any 
changes to the current existing and new source PM limits in subpart MM 
for kraft and soda mill SDTs. The EPA has identified no regulatory 
options for SDTs for further consideration under the subpart MM 
technology review.
    SDT parameter monitoring. Subpart MM specifies monitoring of 
scrubber liquid flow rate and pressure drop for SDTs equipped with wet 
scrubbers. Facilities may have difficulty meeting the minimum pressure 
drop requirement during startup and shutdown, as expected due to the 
reduced (and changing) volumetric flow of stack gases during startup 
and shutdown. The EPA is proposing to consider only scrubber liquid 
flow rate during these periods (i.e., excess emissions would include 
any 3-hour period when BLS are fired that the scrubber flow rate does 
not meet the minimum parameter limits set in the initial performance 
test). This is discussed further in section IV.D.1.
    Based on previous alternative monitoring requests for SDTs, the EPA 
is also proposing to allow operators to use SDT scrubber fan amperage 
as an alternative to pressure drop measurement for SDT dynamic 
scrubbers operating at ambient pressure or for low-energy entrainment 
scrubbers on SDTs where the fan speed does not vary.
5. Sulfite Combustion Units
    When subpart MM was proposed in 1998, there were 15 sulfite pulp 
mills. Today there are only three sulfite mills, including one using 
the magnesium-based sulfite process and two mills using the ammonia 
(NH3)-based sulfite process. The EPA projects no new sulfite mills to 
come online in the United States in the next 5 years. Based on a review 
of permits and ICR data that the EPA has collected for these three 
sulfite mills, we determined that there are a total of eight sulfite 
combustion units currently operating in the United States.
    Sulfite combustion unit PM. Subpart MM of 40 CFR part 63 requires 
existing sulfite combustion units to meet a PM emission limit of 0.040 
gr/dscf at 8-percent O2, based on the use of a fiber-bed 
demister system. Subpart MM requires new sulfite combustion units to 
meet a PM limit of 0.020 gr/dscf at 8-percent O2, based on 
the combined use of a wet scrubber and fiber-bed demister system.\39\ 
The PM emission limits are a surrogate for HAP metals.
---------------------------------------------------------------------------

    \39\ Although any control system could be used to meet the 
emission limits for sulfite combustion units, the existing source 
limit is consistent with the performance of a fiber-bed demister 
system and the new source limit is consistent with the performance 
of a wet scrubber with a fiber-bed demister.
---------------------------------------------------------------------------

    For the 40 CFR part 63 subpart MM technology review, the EPA 
reviewed ICR data on sulfite processes and controls, title V permit 
limits, and PM stack test data for the three sulfite pulp mills 
currently operating in the United States. Each sulfite mill has a 
unique configuration of sulfite combustion units and corresponding 
site-specific limits. Two facilities with sulfite combustion units 
subject to a PM permit limit of 0.04 gr/dscf achieved this limit based 
on actual measurement data submitted (with the exception of one test 
above the limit that was superseded by a more recent test). Another 
facility (Cosmo Specialty Fibers in Cosmopolis, Washington) has a site-
specific PM permit limit of 0.10 gr/dscf for its chemical recovery 
combustion units, and instead reduces PM emissions from the hog fuel 
dryer at the plant site. The chemical recovery combustion units (which 
have a combined stack) have achieved average PM emissions of 0.054 gr/
dscf. The hog fuel dryer is permitted at 10 pounds per hour (lb/hr) of 
PM and has achieved PM emissions of 1.2 and 1.5 lb/hr in two tests. The 
EPA's technology review found no developments in practices, processes, 
or controls since the promulgation of subpart MM for PM emissions from 
sulfite combustion units. The EPA is proposing to retain the 0.040 and 
0.020 gr/dscf at 8-percent O2 PM limits for existing and new 
sulfite combustion units. The EPA has identified no

[[Page 97075]]

regulatory options for sulfite combustion units for further 
consideration under the subpart MM technology review.
    Sulfite combustion unit parameter monitoring. Subpart MM of 40 CFR 
part 63 specifies monitoring of scrubber liquid flow rate and pressure 
drop for sulfite combustion units equipped with wet scrubbers. 
Facilities may have difficulty meeting the minimum pressure drop 
requirement during startup and shutdown, as expected due to the reduced 
(and changing) volumetric flow of stack gases during startup and 
shutdown. The EPA is proposing to consider only scrubber liquid flow 
rate during startup and shutdown periods (i.e., excess emissions would 
include any 3-hour period when spent pulping liquor is fired that the 
scrubber flow rate does not meet the minimum parameter limits set in 
the initial performance test). The EPA is proposing no changes for 
parameter monitoring of the fiber-bed demister system, which is 
addressed under the alternative monitoring provisions of subpart MM.
6. Semichemical Combustion Units
    When 40 CFR part 63, subpart MM, was originally proposed in 1998, 
there were 14 semichemical combustion units at 14 stand-alone 
semichemical pulp mills. Today, there are seven semichemical combustion 
units at seven mills in the United States, at six of which combustion 
units and mills are operating.\40\ Semichemical combustion unit design 
types include: Fluidized-bed reactor (two units, one operating), 
recovery furnace (four units), and rotary liquor kiln (one unit).
---------------------------------------------------------------------------

    \40\ One additional stand-alone semichemical pump mill ceased 
operation in late 2015.
---------------------------------------------------------------------------

    Semichemical combustion unit total hydrocarbon (THC). The current 
40 CFR part 63, subpart MM standards require existing and new 
semichemical combustion units to reduce total gaseous organic HAP 
emissions (measured as THC) by 90 percent or meet a total gaseous 
organic HAP emission limit (measured as THC) of 2.97 lb/ton of BLS 
fired.
    For the 40 CFR part 63, subpart MM RTR, the EPA reviewed ICR data 
on processes and control configurations, title V permit limits, and THC 
stack test data for the stand-alone semichemical pulp mills currently 
operating in the United States. The review of permit limits indicated 
that all semichemical combustion units are subject to the 2.97 lb/ton 
BLS THC limit specified in subpart MM for existing and new units. 
Performance of the different semichemical combustion units varies 
considerably for THC. While most units achieve the 2.97 lb/ton BLS THC 
limit, at least one unit relied on the 90-percent reduction compliance 
option included in subpart MM to address variability. The EPA has 
identified no regulatory options for semichemical combustion units for 
purposes of the subpart MM RTR, given that no practices, processes, or 
controls beyond those considered during the original rule development 
have emerged.
    Semichemical combustion unit parameter monitoring. Subpart MM of 40 
CFR part 63 requires semichemical combustion units using RTOs to 
measure and record RTO operating temperature to demonstrate compliance 
with the standard for gaseous organic HAP (measured as THC). As noted 
previously, no practices, processes, or controls beyond those 
considered during the original rule development have emerged. 
Consequently, the EPA is proposing no changes for the current parameter 
monitoring requirements.
D. What other actions are we proposing?
    In addition to the proposed actions described above, we are 
proposing additional revisions. We are proposing revisions to the SSM 
provisions of the MACT rule in order to ensure that they are consistent 
with the court decision in Sierra Club v. EPA, 551 F.3d 1019 (D.C. Cir. 
2008), which vacated two provisions that exempted sources from the 
requirement to comply with otherwise applicable CAA section 112(d) 
emission standards during periods of SSM. We also are proposing various 
other changes, including 5-year periodic emissions testing for selected 
process equipment, semiannual electronic reporting for all excess 
emissions reports, electronic submittal of compliance reports (which 
include performance test reports), incorporation by reference, and 
various technical and editorial changes. Our analyses and proposed 
changes related to these issues are discussed in sections IV.D.1 
through 6 of this preamble.
1. Startup, Shutdown, and Malfunction
    In its 2008 decision in Sierra Club v. EPA, 551 F.3d 1019 (D.C. 
Cir. 2008), the United States Court of Appeals for the District of 
Columbia Circuit vacated portions of two provisions in the EPA's CAA 
section 112 regulations governing the emissions of HAPs during periods 
of SSM. Specifically, the Court vacated the SSM exemption contained in 
40 CFR 63.6(f)(1) and 40 CFR 63.6(h)(1), holding that under section 
302(k) of the CAA, emissions standards or limitations must be 
continuous in nature and that the SSM exemption violates the CAA's 
requirement that some CAA section 112 standards apply continuously.
    We are proposing the elimination of the SSM exemption in this rule. 
Consistent with Sierra Club v. EPA, we are proposing standards in this 
rule that apply at all times. We are also proposing several revisions 
to Table 1 (the General Provisions Applicability Table) as is explained 
in more detail below. For example, we are proposing to eliminate the 
incorporation of the General Provisions' requirement that the source 
develop an SSM plan. We also are proposing to eliminate and revise 
certain recordkeeping and reporting requirements related to the SSM 
exemption as further described below.
    The EPA has attempted to ensure that the provisions we are 
proposing to eliminate are inappropriate, unnecessary, or redundant in 
the absence of the SSM exemption. We are specifically seeking comment 
on whether we have successfully done so.
    Periods of startup and shutdown. In reviewing the standards in this 
rule, the EPA has taken into account startup and shutdown periods and, 
for the reasons explained below, is not proposing alternate standards 
for those periods.
    Subpart MM of 40 CFR part 63 requires continuous opacity monitoring 
to indicate ongoing compliance with the PM emission limits. In 
developing proposed standards for subpart MM, the EPA reviewed numerous 
continuous opacity monitoring datasets that included periods of startup 
and shutdown, and concluded that the affected units will be able to 
comply with the proposed standards at all times. The proposed subpart 
MM also requires RTO operating temperature and ESP and wet scrubber 
parameter monitoring. Parameter limits apply at all times, including 
during startup and shutdown. The proposed subpart MM requires RTO 
operating temperature and wet scrubber and ESP operating parameters to 
be recorded at least once every 15 minutes. Subpart MM specifies 
corrective action levels in 40 CFR 63.864(k)(1) and violation levels in 
40 CFR 63.864(k)(2) which would be reported as excess emissions under 
40 CFR 63.867(c). For RTO temperature, subpart MM requires corrective 
action when any 1-hour temperature falls below the average temperature 
established during the performance test. Subpart MM considers any 3-
hour RTO temperature that falls below the average established during 
the performance test to be a violation. Subpart MM requires the ESP and 
scrubber parameters to be averaged over a 3-hour block, except for ESPs 
with COMS, which would have

[[Page 97076]]

ESP parameters averaged semiannually. The corrective action level for 
wet scrubber and ESP operating parameters (when opacity is not also 
measured) is triggered when any 3-hour average is outside of the limit 
established during the performance test. A violation would occur when 
six or more of the 3-hour average parameter values within a 6-month 
period are outside of the limits established during the performance 
test. Violations based on opacity would be considered over a semiannual 
period. For new or existing kraft or soda recovery furnaces, a 
violation would occur when any opacity is greater than 20 percent for 2 
percent or more of the operating time when spent liquor is fired within 
a semiannual period. For new or existing lime kilns, a violation would 
occur when any opacity is greater than 20 percent for 1 percent or more 
of the operating time when lime mud is fired in a semiannual period. A 
violation would also occur when the recovery furnace or lime kiln ESP 
secondary voltage and secondary current (or total secondary power) 
averaged over the semiannual period are below the minimum operating 
limits established during the performance test, with the exception of 
secondary current (or total secondary power) during periods of startup 
and shutdown.
    To address the need for ESPs to warm to a specified temperature 
(typically above 200[emsp14][deg]F) before full power is applied to the 
transformer-rectifier set, the EPA is proposing to define excess 
emissions (i.e., the corrective action and violation levels) as opacity 
and ESP parameter measurements below the minimum requirements during 
times when BLS or lime mud is fired (as applicable), based on several 
responses to the ICR indicating that mills with ESP minimum temperature 
requirements bring the ESP online before introducing BLS or lime mud 
into the recovery furnace or lime kiln, respectively. The EPA is also 
proposing language that would allow affected units to use wet scrubber 
liquid flow rate to demonstrate compliance during periods of startup 
and shutdown because pressure drop is difficult to achieve during these 
periods.
    Periods of malfunction. Periods of startup, normal operations, and 
shutdown are all predictable and routine aspects of a source's 
operations. Malfunctions, in contrast, are neither predictable nor 
routine. Instead they are, by definition, sudden, infrequent, and not 
reasonably preventable failures of emissions control, process or 
monitoring equipment. (40 CFR 63.2) (Definition of malfunction). The 
EPA interprets CAA section 112 as not requiring emissions that occur 
during periods of malfunction to be factored into development of CAA 
section 112 standards. Under CAA section 112, emissions standards for 
new sources must be no less stringent than the level ``achieved'' by 
the best controlled similar source and for existing sources generally 
must be no less stringent than the average emission limitation 
``achieved'' by the best performing 12 percent of sources in the 
category. There is nothing in CAA section 112 that directs the Agency 
to consider malfunctions in determining the level ``achieved'' by the 
best performing sources when setting emission standards. As the 
District of Columbia Circuit Court has recognized, the phrase ``average 
emissions limitation achieved by the best performing 12 percent of'' 
sources ``says nothing about how the performance of the best units is 
to be calculated.'' Nat'l Ass'n of Clean Water Agencies v. EPA, 734 
F.3d 1115, 1141 (D.C. Cir. 2013). While the EPA accounts for 
variability in setting emissions standards, nothing in CAA section 112 
requires the Agency to consider malfunctions as part of that analysis. 
A malfunction should not be treated in the same manner as the type of 
variation in performance that occurs during routine operations of a 
source. A malfunction is a failure of the source to perform in a 
``normal or usual manner'' and no statutory language compels the EPA to 
consider such events in setting section CAA 112 standards.
    Further, accounting for malfunctions in setting emission standards 
would be difficult, if not impossible, given the myriad of different 
types of malfunctions that can occur across all sources in the category 
and given the difficulties associated with predicting or accounting for 
the frequency, degree, and duration of various malfunctions that might 
occur. As such, the performance of units that are malfunctioning is not 
``reasonably'' foreseeable. See, e.g., Sierra Club v. EPA, 167 F.3d 
658, 662 (D.C. Cir. 1999) (``The EPA typically has wide latitude in 
determining the extent of data-gathering necessary to solve a problem. 
We generally defer to an agency's decision to proceed on the basis of 
imperfect scientific information, rather than to `invest the resources 
to conduct the perfect study.' '') See also, Weyerhaeuser v. Costle, 
590 F.2d 1011, 1058 (D.C. Cir. 1978) (``In the nature of things, no 
general limit, individual permit, or even any upset provision can 
anticipate all upset situations. After a certain point, the 
transgression of regulatory limits caused by `uncontrollable acts of 
third parties,' such as strikes, sabotage, operator intoxication or 
insanity, and a variety of other eventualities, must be a matter for 
the administrative exercise of case-by-case enforcement discretion, not 
for specification in advance by regulation.''). In addition, emissions 
during a malfunction event can be significantly higher than emissions 
at any other time of source operation. For example, if an air pollution 
control device with 99-percent removal goes off-line as a result of a 
malfunction (as might happen if, for example, the bags in a baghouse 
catch fire) and the emission unit is a steady state type unit that 
would take days to shut down, the source would go from 99-percent 
control to zero control until the control device was repaired. The 
source's emissions during the malfunction would be 100 times higher 
than during normal operations. As such, the emissions over a 4-day 
malfunction period would exceed the annual emissions of the source 
during normal operations. As this example illustrates, accounting for 
malfunctions could lead to standards that are not reflective of (and 
significantly less stringent than) levels that are achieved by a well-
performing non-malfunctioning source. It is reasonable to interpret CAA 
section 112 to avoid such a result. The EPA's approach to malfunctions 
is consistent with CAA section 112 and is a reasonable interpretation 
of the statute.
    In the event that a source fails to comply with the applicable CAA 
section 112(d) standards as a result of a malfunction event, the EPA 
would determine an appropriate response based on, among other things, 
the good faith efforts of the source to minimize emissions during 
malfunction periods, including preventative and corrective actions, as 
well as root cause analyses to ascertain and rectify excess emissions. 
The EPA would also consider whether the source's failure to comply with 
the CAA section 112(d) standard was, in fact, sudden, infrequent, not 
reasonably preventable, and was not instead caused in part by poor 
maintenance or careless operation. 40 CFR 63.2 (definition of 
malfunction).
    If the EPA determines in a particular case that an enforcement 
action against a source for violation of an emission standard is 
warranted, the source can raise any and all defenses in that 
enforcement action and the Federal District Court will determine what, 
if any, relief is appropriate. The same is true for citizen enforcement 
actions. Similarly, the presiding officer in an administrative 
proceeding can consider any defense raised and determine

[[Page 97077]]

whether administrative penalties are appropriate.
    In summary, the EPA interpretation of the CAA and, in particular, 
CAA section 112 is reasonable and encourages practices that will avoid 
malfunctions. Administrative and judicial procedures for addressing 
exceedances of the standards fully recognize that violations may occur 
despite good faith efforts to comply and can accommodate those 
situations.
a. General Duty
    We are proposing to revise the General Provisions table (Table 1) 
entry for 40 CFR 63.6(e) by re-designating it as 40 CFR 63.6(e)(1)(i) 
and changing the ``yes'' in column 3 to a ``no.'' Section 63.6(e)(1)(i) 
describes the general duty to minimize emissions. Some of the language 
in that section is no longer necessary or appropriate in light of the 
elimination of the SSM exemption. We are proposing instead to add 
general duty regulatory text at 40 CFR 63.860(d) that reflects the 
general duty to minimize emissions while eliminating the reference to 
periods covered by an SSM exemption. The current language in 40 CFR 
63.6(e)(1)(i) characterizes what the general duty entails during 
periods of SSM. With the elimination of the SSM exemption, there is no 
need to differentiate between normal operations and SSM events in 
describing the general duty. Therefore, the language the EPA is 
proposing for 40 CFR 63.860(d) does not include that language from 40 
CFR 63.6(e)(1).
    We are also proposing to revise the General Provisions table (Table 
1) to add an entry for 40 CFR 63.6(e)(1)(ii) and include a ``no'' in 
column 3. Section 63.6(e)(1)(ii) imposes requirements that are not 
necessary with the elimination of the SSM exemption or are redundant 
with the general duty requirement being added at 40 CFR 63.860(d).
b. SSM Plan
    We are proposing to revise the General Provisions table (Table 1) 
to add an entry for 40 CFR 63.6(e)(3) and include a ``no'' in column 3. 
Generally, the paragraphs under 40 CFR 63.6(e)(3) require development 
of an SSM plan and specify SSM recordkeeping and reporting requirements 
related to the SSM plan. As noted, the EPA is proposing to remove the 
SSM exemptions. Therefore, affected units will be subject to an 
emission standard during such events. The applicability of a standard 
during such events will ensure that sources have ample incentive to 
plan for and achieve compliance and, thus, the SSM plan requirements 
are no longer necessary.
c. Compliance With Standards
    We are proposing to revise the General Provisions table (Table 1) 
entries for 40 CFR 63.6(f) and (h) by re-designating these sections as 
40 CFR 63.6(f)(1) and (h)(1) and including a ``no'' in column 3. The 
current language of 40 CFR 63.6(f)(1) and (h)(1) exempts sources from 
non-opacity and opacity standards during periods of SSM. As discussed 
above, the court in Sierra Club vacated the exemptions contained in 
this provision and held that the CAA requires that some CAA section 112 
standard apply continuously. Consistent with Sierra Club, the EPA is 
proposing to revise standards in this rule to apply at all times.
d. Performance Testing
    We are proposing to revise the General Provisions table (Table 1) 
entry for 40 CFR 63.7(e) by re-designating it as 40 CFR 63.7(e)(1) and 
including a ``no'' in column 3. Section 63.7(e)(1) describes 
performance testing requirements. The EPA is instead proposing to add a 
performance testing requirement at 40 CFR 63.865. The proposed 
performance testing provisions require testing under representative 
operating conditions, excluding periods of startup and shutdown. As in 
40 CFR 63.7(e)(1), performance tests conducted under this subpart 
should not be conducted during malfunctions because conditions during 
malfunctions are often not representative of normal operating 
conditions. The EPA is proposing to add language that requires the 
owner or operator to record the process information that is necessary 
to document operating conditions during the test and include in such 
record an explanation to support that such conditions represent normal 
operation. Section 63.7(e) requires that the owner or operator make 
available to the Administrator such records ``as may be necessary to 
determine the condition of the performance test'' available to the 
Administrator upon request, but does not specifically require the 
information to be recorded. The regulatory text the EPA is proposing to 
add to this provision builds on that requirement and makes explicit the 
requirement to record the information.
e. Monitoring
    We are proposing to revise the General Provisions table (Table 1) 
by re-designating 40 CFR 63.8(c) as 40 CFR 63.8(c)(1), adding entries 
for 40 CFR 63.8(c)(1)(i) through (iii) and including ``no'' in column 3 
for paragraphs (i) and (iii). The cross-references to the general duty 
and SSM plan requirements in those subparagraphs are not necessary in 
light of other requirements of 40 CFR 63.8 that require good air 
pollution control practices (40 CFR 63.8(c)(1)) and that set out the 
requirements of a quality control program for monitoring equipment (40 
CFR 63.8(d)).
    We are also proposing to revise the General Provisions table (Table 
1) by adding an entry for 40 CFR 63.8(d)(3) and including a ``no'' in 
column 3. The final sentence in 40 CFR 63.8(d)(3) refers to the General 
Provisions' SSM plan requirement which is no longer applicable. The EPA 
is proposing to add to the rule at 40 CFR 63.864(f) text that is 
identical to 40 CFR 63.8(d)(3) except that the final sentence is 
replaced with the following sentence: ``The program of corrective 
action should be included in the plan required under 40 CFR 
63.8(d)(2).''
f. Recordkeeping
    We are proposing to revise the General Provisions table (Table 1) 
by adding an entry for 40 CFR 63.10(b)(2)(i) and including a ``no'' in 
column 3. Section 63.10(b)(2)(i) describes the recordkeeping 
requirements during startup and shutdown. These recording provisions 
are no longer necessary because the EPA is proposing that recordkeeping 
and reporting applicable to normal operations will apply to startup and 
shutdown. Special provisions applicable to startup and shutdown, such 
as a startup and shutdown plan, have been removed from the rule (with 
exceptions discussed below) thereby reducing the need for additional 
recordkeeping for startup and shutdown periods.
    Records of startup and shutdown periods are proposed to be required 
under 40 CFR 63.866(c)(8) to help characterize minor exceptions to 
reporting. The EPA is proposing no reporting of wet scrubber pressure 
drop or ESP secondary current (or total secondary power) during periods 
of startup and shutdown because it is not feasible to meet operating 
limits established under normal operation for these parameters during 
startup and shutdown. Instead, the EPA is proposing that wet scrubber 
liquid flow rate (or fan amperage) and ESP secondary voltage be 
monitored during startup and shutdown.
    We are also proposing to revise the General Provisions table (Table 
1) by adding an entry for 40 CFR 63.10(b)(2)(ii) and including a ``no'' 
in column 3. Section 63.10(b)(2)(ii) describes the recordkeeping 
requirements during a malfunction. The EPA is proposing to add such

[[Page 97078]]

requirements to 40 CFR 63.866(d). The regulatory text we are proposing 
to add differs from the General Provisions it is replacing in that the 
General Provisions requires the creation and retention of a record of 
the occurrence and duration of each malfunction of process, air 
pollution control, and monitoring equipment. The EPA is proposing that 
this requirement apply to any failure to meet an applicable standard 
and is requiring that the source record the date, time, and duration of 
the failure rather than the ``occurrence.'' The EPA is also proposing 
to add to 40 CFR 63.866(d) a requirement that sources keep records that 
include a list of the affected source or equipment and actions taken to 
minimize emissions, an estimate of the quantity of each regulated 
pollutant emitted over the emission limit for which the source failed 
to meet the standard, and a description of the method used to estimate 
the emissions. Examples of such methods would include product-loss 
calculations, mass balance calculations, measurements when available, 
or engineering judgment based on known process parameters. The EPA is 
proposing to require that sources keep records of this information to 
ensure that there is adequate information to allow the EPA to determine 
the severity of any failure to meet a standard, and to provide data 
that may document how the source met the general duty to minimize 
emissions when the source has failed to meet an applicable standard.
    We are also proposing to revise the General Provisions table (Table 
1) by adding an entry for 40 CFR 63.10(b)(2)(iv) and (v) and including 
a ''no'' in column 3. When applicable, the provision requires sources 
to record actions taken during SSM events when actions were 
inconsistent with their SSM plan. The requirement is no longer 
appropriate because SSM plans will no longer be required. The 
requirement previously applicable under 40 CFR 63.10(b)(2)(iv)(B) to 
record actions to minimize emissions and record corrective actions is 
now applicable by reference to 40 CFR 63.866(d).
    We are also proposing to revise the General Provisions table (Table 
1) by adding an entry for 40 CFR 63.10(c)(15) and including a ``no'' in 
column 3. The EPA is proposing that 40 CFR 63.10(c)(15) no longer 
apply. When applicable, the provision allows an owner or operator to 
use the affected source's SSM plan or records kept to satisfy the 
recordkeeping requirements of the SSM plan, specified in 40 CFR 
63.6(e), to also satisfy the requirements of 40 CFR 63.10(c)(10) 
through (12). The EPA is proposing to eliminate this requirement 
because SSM plans would no longer be required, and, therefore, 40 CFR 
63.10(c)(15) no longer serves any useful purpose for affected units.
g. Reporting
    We are proposing to revise the General Provisions table (Table 1) 
entry for 40 CFR 63.10(d)(5) by re-designating it as 40 CFR 
63.10(d)(5)(i) and changing the ``yes'' in column 3 to a ``no.'' 
Section 63.10(d)(5)(i) describes the periodic reporting requirements 
for startups, shutdowns, and malfunctions. To replace the General 
Provisions reporting requirement, the EPA is proposing to add reporting 
requirements to 40 CFR 63.867(c). The replacement language differs from 
the General Provisions requirement in that it eliminates periodic SSM 
reports as a stand-alone report. We are proposing language that 
requires sources that fail to meet an applicable standard at any time 
to report the information concerning such events in the semiannual 
report to be required under the proposed rule. We are proposing that 
the report must contain the number, date, time, duration, and the cause 
of such events (including unknown cause, if applicable), a list of the 
affected source or equipment, an estimate of the quantity of each 
regulated pollutant emitted over any emission limit, and a description 
of the method used to estimate the emissions.
    Examples of such methods would include product-loss calculations, 
mass balance calculations, measurements when available, or engineering 
judgment based on known process parameters. The EPA is proposing this 
requirement to ensure that there is adequate information to determine 
compliance, to allow the EPA to determine the severity of the failure 
to meet an applicable standard, and to provide data that may document 
how the source met the general duty to minimize emissions during a 
failure to meet an applicable standard.
    We will no longer require owners or operators to determine whether 
actions taken to correct a malfunction are consistent with an SSM plan, 
because plans would no longer be required. The proposed amendments, 
therefore, eliminate the cross reference to 40 CFR 63.10(d)(5)(i) that 
contains the description of the previously required SSM report format 
and submittal schedule from this section. These specifications are no 
longer necessary because the events will be reported in otherwise 
required reports with similar format and submittal requirements.
    We are also proposing to revise the General Provisions table (Table 
1) to add an entry for 40 CFR 63.10(d)(5)(ii) and include a ``no'' in 
column 3. Section 63.10(d)(5)(ii) describes an immediate report for 
startups, shutdown, and malfunctions when a source failed to meet an 
applicable standard, but did not follow the SSM plan. We will no longer 
require owners and operators to report when actions taken during a 
startup, shutdown, or malfunction were not consistent with an SSM plan, 
because plans would no longer be required.
2. 5-Year Periodic Emissions Testing
    As part of an ongoing effort to improve compliance with various 
federal air emission regulations, the EPA reviewed the testing and 
monitoring requirements of 40 CFR part 63, subpart MM and is proposing 
the following change. The EPA is proposing to require facilities 
complying with the standards for chemical recovery combustion sources 
at kraft, soda, sulfite, and stand-alone semichemical pulp mills to 
conduct periodic air emissions performance testing, with the first of 
the periodic performance tests to be conducted within 3 years of the 
effective date of the revised standards and thereafter before the 
facilities renew their 40 CFR part 70 operating permits, but no longer 
than 5 years following the previous performance test. Periodic 
performance tests are already required by permitting authorities for 
some facilities. Further, the EPA believes that requiring periodic 
performance tests will help to ensure that control systems are properly 
maintained over time, thereby reducing the potential for acute 
emissions episodes. This proposal would require periodic air emissions 
testing for filterable PM once every 5 years for existing and new kraft 
and soda recovery furnaces, SDTs, and lime kilns and sulfite combustion 
units. In addition, this proposal would require air emissions testing 
for methanol once every 5 years for new kraft and soda recovery 
furnaces. This proposal would also require periodic air emissions 
testing for THC for existing and new semichemical combustion units.
3. Continuous Parameter Monitoring System (CPMS) Operating Limits
    We are proposing to specify procedures for establishing operating 
limits based on data recorded by CPMS. The 40 CFR part 63, subpart MM 
emission standards are comprised of numerical emission limits, with 
compliance demonstrated through periodic performance tests, and 
operating limits such as opacity limits or continuously monitored 
parameter limits used to demonstrate ongoing compliance in between 
performance

[[Page 97079]]

tests. Currently, the subpart MM regulatory text refers extensively to 
operating parameter ranges and is not as specific as more recent 
NESHAPs in specifying how operating limits are to be determined. 
Therefore, we are proposing language to clarify the procedures for 
establishing parameter limits.
    As noted previously, we are proposing ESP parameter monitoring 
requirements for recovery furnaces and lime kilns with ESPs or combined 
ESP and wet scrubber controls. This proposal would require ESP 
parameters be recorded at least once every successive 15-minute period, 
and the recorded readings be reduced to semiannual averages for ESPs 
(i.e., where opacity monitoring requirements also apply) or 3-hour 
averages for ESPs followed by a wet scrubber. Similarly, this proposal 
would require wet scrubber parameters, including pressure drop across 
the scrubber (or fan amperage for certain SDT scrubbers) and scrubbing 
liquid flow rate, be recorded at least every 15-minutes and reduced to 
3-hour averages. This proposal would require RTO temperature be 
recorded every 15 minutes and reduced to a 1-hour average for purposes 
of assessing when corrective action is required under 40 CFR 
63.864(k)(1), and reduced to a 3-hour average under 40 CFR 63.864(k)(2) 
for purposes of assessing violations.
    We are proposing that the ESP and wet scrubber operating limits be 
established as the average of the parameter values associated with each 
performance test run. For example, the proposal would require the 
recorded readings during each test run be averaged to arrive at the 
parameter value associated with three test runs, and the three values 
be averaged to arrive at the operating limit. The proposal would 
require these revised procedures be used beginning with the first 
periodic performance test proposed to be required under 40 CFR 63.865. 
Wet scrubbers and ESPs have minimum operating limits, such that the EPA 
would consider 3-hour average values below the minimum operating limit 
to be a monitoring exceedance to be reported under 40 CFR 63.867(c). 
Also, in the spirit of ensuring continuous compliance, we are proposing 
to eliminate the language in 40 CFR 63.864(k)(3) that allowed no more 
than one non-opacity monitoring exceedance to be attributed to any 24-
hour period.
4. Reporting Frequency
    Subpart MM of 40 CFR part 63 currently requires owners and 
operators of subpart MM facilities to submit quarterly excess emissions 
reports for monitoring exceedances and periods of noncompliance and 
semiannual reports when no excess emissions have occurred during the 
reporting period. These excess emission reports are typically submitted 
as a hard copy to the delegated authority, and reports in this form 
usually are not readily available for the EPA and public to analyze. 
The Agency is proposing that semiannual electronic reporting would 
provide ample data to assess a facility's performance with regard to 
the emission standards in subpart MM. The EPA is proposing that all 
excess emissions reports be submitted on a semiannual basis, to conform 
to the semiannual reporting frequency employed by the electronic 
reporting system discussed in the following section. The EPA requests 
comment on maintaining quarterly reporting for reports of monitoring 
exceedances and periods of noncompliance.
5. Electronic Reporting
    The EPA is proposing that owners and operators of 40 CFR part 63, 
subpart MM facilities submit electronic copies of compliance reports, 
which include performance test reports, semiannual reports, and 
notifications, through the EPA's Central Data Exchange (CDX) using the 
Compliance and Emissions Data Reporting Interface (CEDRI). 
Specifically, we are proposing that owners and operators submit 
performance test reports through the Electronic Reporting Tool (ERT) 
and submit notifications and semiannual reports through CEDRI. The EPA 
believes that the electronic submittal of the reports addressed in this 
proposed rulemaking will increase the usefulness of the data contained 
in those reports, is in keeping with current trends in data 
availability, will further assist in the protection of public health 
and the environment, and will ultimately result in less burden on the 
regulated community. Under current requirements, paper reports are 
often stored in filing cabinets or boxes, which make the reports more 
difficult to obtain and use for data analysis and sharing. Electronic 
storage of such reports would make data more accessible for review, 
analyses, and sharing. Electronic reporting can also eliminate paper-
based, manual processes, thereby saving time and resources, simplifying 
data entry, eliminating redundancies, minimizing data reporting errors 
and providing data quickly and accurately to the affected facilities, 
air agencies, the EPA, and the public.
    In 2011, in response to Executive Order 13563, the EPA developed a 
plan \41\ to periodically review its regulations to determine if they 
should be modified, streamlined, expanded, or repealed in an effort to 
make regulations more effective and less burdensome. The plan includes 
replacing outdated paper reporting with electronic reporting. In 
keeping with this plan and the White House's Digital Government 
Strategy,\42\ in 2013 the EPA issued an agency-wide policy specifying 
that new regulations will require reports to be electronic to the 
maximum extent possible. By requiring electronic submission of 
specified reports in this proposed rule, the EPA is taking steps to 
implement this policy.
---------------------------------------------------------------------------

    \41\ Improving Our Regulations: Final Plan for Periodic 
Retrospective Reviews of Existing Regulations, August 2011. 
Available at https://www.epa.gov/sites/roduction/files/2015-09-/documents/eparetroreviewplan-aug2011_0.pdf.
    \42\ Digital Government: Buildiing a 21st Century Platform to 
Better Serve the American People, May 2012. Available at http://www.whitehouse.gov/sites/default/files/omb/egov/digital-government/digital-government-strategy/pdf.
---------------------------------------------------------------------------

    The EPA Web site that stores the submitted electronic data, 
WebFIRE, will be easily accessible to everyone and will provide a user-
friendly interface that any stakeholder could access. By making data 
readily available, electronic reporting increases the amount of data 
that can be used for many purposes. One example is the development of 
emissions factors. An emissions factor is a representative value that 
attempts to relate the quantity of a pollutant released to the 
atmosphere with an activity associated with the release of that 
pollutant (e.g., kilograms of particulate emitted per megagram of coal 
burned). Such factors facilitate the estimation of emissions from 
various sources of air pollution and are an important tool in 
developing emissions inventories, which in turn are the basis for 
numerous efforts, including trends analysis, regional, and local scale 
air quality modeling, regulatory impact assessments, and human exposure 
modeling. Emissions factors are also widely used in regulatory 
applicability determinations and in permitting decisions.
    The EPA has received feedback from stakeholders asserting that many 
of the EPA's emissions factors are outdated or not representative of a 
particular industry emission source. While the EPA believes that the 
emissions factors are suitable for their intended purpose, we recognize 
that the quality of emissions factors varies based on the extent and 
quality of underlying data. We also recognize that emissions profiles 
on different pieces of equipment can change over time due to

[[Page 97080]]

a number of factors (fuel changes, equipment improvements, industry 
work practices), and it is important for emissions factors to be 
updated to keep up with these changes. The EPA is currently pursuing 
emissions factor development improvements that include procedures to 
incorporate the source test data that we are proposing be submitted 
electronically. By requiring the electronic submission of the reports 
identified in this proposed action, the EPA would be able to access and 
use the submitted data to update emissions factors more quickly and 
efficiently, creating factors that are characteristic of what is 
currently representative of the relevant industry sector. Likewise, an 
increase in the number of test reports used to develop the emissions 
factors will provide more confidence that the factor is of higher 
quality and representative of the whole industry sector.
    Additionally, by making the records, data and reports addressed in 
this proposed rulemaking readily available, the EPA, the regulated 
community and the public will benefit when the EPA conducts periodic 
reviews of its rules. As a result of having performance test reports 
and air emission reports readily accessible, our ability to carry out 
comprehensive reviews will be increased and achieved within a shorter 
period of time. These data will provide useful information on control 
efficiencies being achieved and maintained in practice within a source 
category and across source categories for regulated sources and 
pollutants. These reports can also be used to inform the technology-
review process by providing information on improvements to add-on 
control technology and new control technology.
    Under an electronic reporting system, the EPA's Office of Air 
Quality Planning and Standards (OAQPS) would have air emissions and 
performance test data in hand; OAQPS would not have to collect these 
data from the EPA Regional offices or from delegated authorities or 
industry sources in cases where these reports are not submitted to the 
EPA Regional offices. Thus, we anticipate fewer or less substantial 
ICRs in conjunction with prospective CAA-required technology and risk-
based reviews may be needed. We expect this to result in a decrease in 
time spent by industry to respond to data collection requests. We also 
expect the ICRs to contain less extensive stack testing provisions, as 
we will already have stack test data electronically. Reduced testing 
requirements would be a cost savings to industry. The EPA should also 
be able to conduct these required reviews more quickly, as OAQPS will 
not have to include the ICR collection time in the process or spend 
time collecting reports from the EPA Regional Offices. While the 
regulated community may benefit from a reduced burden of ICRs, the 
general public benefits from the Agency's ability to provide these 
required reviews more quickly, resulting in increased public health and 
environmental protection.
    Electronic reporting could minimize submission of unnecessary or 
duplicative reports in cases where facilities report to multiple 
government agencies and the agencies opt to rely on the EPA's 
electronic reporting system to view report submissions. Where delegated 
authorities continue to require a paper copy of these reports and will 
accept a hard copy of the electronic report, facilities will have the 
option to print paper copies of the electronic reporting forms to 
submit to the delegated authorities, and, thus, minimize the time spent 
reporting to multiple agencies. Additionally, maintenance and storage 
costs associated with retaining paper records could likewise be 
minimized by replacing those records with electronic records of 
electronically submitted data and reports.
    Delegated authorities could benefit from more streamlined and 
automated review of the electronically submitted data. For example, 
because the performance test data would be readily-available in a 
standard electronic format, delegated authorities would be able to 
review reports and data electronically rather than having to conduct a 
review of the reports and data manually. Having reports and associated 
data in electronic format will facilitate review through the use of 
software ``search'' options, as well as the downloading and analyzing 
of data in spreadsheet format. Additionally, delegated authorities 
would benefit from the reported data being accessible to them through 
the EPA's electronic reporting system wherever and whenever they want 
or need access (as long as they have access to the Internet). The 
ability to access and review air emission report information 
electronically will assist delegated authorities to more quickly and 
accurately determine compliance with the applicable regulations, 
potentially allowing a faster response to violations which could 
minimize harmful air emissions. This benefits both delegated 
authorities and the general public.
    The proposed electronic reporting of data is consistent with 
electronic data trends (e.g., electronic banking and income tax 
filing). Electronic reporting of environmental data is already common 
practice in many media offices at the EPA. The changes being proposed 
in this rulemaking are needed to continue the EPA's transition to 
electronic reporting.
    As noted above, we are proposing that 40 CFR part 63, subpart MM 
performance test reports be submitted through the EPA's ERT. All of the 
test methods listed under subpart MM are currently supported by the 
ERT, with the exception of Method 308 in 40 CFR part 63, appendix A. 
The proposal would require that performance test results collected 
using test methods that are not supported by the ERT as listed on the 
EPA's ERT Web site at the time of the test be submitted in portable 
document format (PDF) using the attachment module of the ERT.
    In addition to electronically reporting the results of performance 
tests, we are proposing the requirement to electronically submit 
notifications and the semiannual excess emissions report and/or summary 
report required in 40 CFR 63.867. The proposal would require the owner 
or operator use the appropriate electronic form or spreadsheet template 
in CEDRI for the subpart or an alternate electronic file format 
consistent with the form's extensible markup language (XML) schema. If 
neither the reporting form nor the spreadsheet template specific to the 
subpart are available at the time that the report is due, the owner or 
operator would upload an electronic copy of the report in CEDRI. The 
owner or operator would begin submitting reports electronically using 
the reporting form or spreadsheet template with the next report that is 
due, once the electronic form or template has been available for at 
least 90 days. The EPA is currently working to develop the forms and a 
spreadsheet template for subpart MM. We are specifically taking comment 
on the content, layout, and overall design of the forms and spreadsheet 
template, which are discussed in a memorandum in the docket titled 
Electronic Reporting for Subpart MM Excess Emission Reports.
    As part of this review, we have specified in 40 CFR 63.867 the 
reporting requirements from the 40 CFR part 63 General Provisions for 
the excess emissions and summary reports. We believe that specifying 
the General Provision reporting requirements for the proposed 
semiannual reports in 40 CFR part 63, subpart MM, will help eliminate 
confusion as to which report is submitted (e.g., full excess emissions 
report or summary report) and the content of the required report. Based 
on the criteria specified in the General Provisions, subpart MM 
requires a full

[[Page 97081]]

excess emissions report under any of the following three conditions: 
(1) The total duration of monitoring exceedances is one percent or more 
of the total reporting period operating time, or (2) the total 
continuous monitoring system (CMS) downtime is five percent or more of 
the total reporting period operating time, or (3) any violations 
according to 40 CFR 63.864(k)(2) occurred. Subpart MM requires only an 
abbreviated summary report when none of the three conditions apply for 
the semiannual reporting period.
    As stated in 40 CFR 63.867(a), the proposal also requires that 
notifications be reported electronically though CEDRI. Currently, there 
are no templates for notifications in CEDRI for this subpart. 
Therefore, the owner or operator must submit their notifications in 
PDF. Examples of such notifications include (but are not limited to) 
the following: Initial notifications, notifications of compliance 
status, notifications of a performance test, notifications of CMS 
performance evaluation, and notifications of opacity and visible 
emissions observations.
6. Incorporation by Reference Under 1 CFR part 51
    The EPA is proposing regulatory text that includes incorporation by 
reference (IBR). In accordance with requirements of 1 CFR 51.5, the EPA 
is proposing to incorporate by reference the following document 
described in the amendments to 40 CFR 63.14:
     EPA-454/R-98-015, Office of Air Quality Planning and 
Standards (OAQPS), Fabric Filter Bag Leak Detection Guidance, September 
1997, IBR approved for 40 CFR 63.864(e).
    This document provides guidance on the use of triboelectric 
monitors as fabric filter bag leak detectors. The document includes 
fabric filter and monitoring system descriptions; guidance on monitor 
selection, installation, setup, adjustment, and operation; and quality 
assurance procedures. The EPA has made, and will continue to make, this 
document generally available electronically through http://www.regulations.gov and/or in hard copy at the appropriate EPA office 
(see the ADDRESSES section of this preamble for more information). In 
addition, this document is available on the EPA Technical Air Pollution 
Resources Emission Measurement Center Web page (https://www.epa.gov/emc) under Continuous Emission Monitoring.
7. Technical and Editorial Changes
    The following lists additional changes that address technical and 
editorial corrections:
     Made revisions throughout 40 CFR part 63, subpart MM, to 
clarify the location in 40 CFR part 60 of applicable EPA test methods;
     Made revisions throughout 40 CFR part 63, subpart MM, to 
update the facility name for Cosmo Specialty Fibers;
     Revised the definitions section in 40 CFR 63.861 to:
    [cir] Remove the definition for ``black liquor gasification'' and 
remove reference to black liquor gasification in the definitions for 
``kraft recovery furnace,'' ``recovery furnace,'' ``semichemical 
combustion unit,'' and ``soda recovery furnace'';
    [cir] Remove the SSM exemption from the definition for 
``modification'';
    [cir] Clarify that the definition for ``particulate matter'' refers 
to filterable PM;
    [cir] Removed reference to use of one-half of the method detection 
limit for non-detect Method 29 measurements within the definition of 
``hazardous air pollutant (HAP) metals'' because the full detection 
limit in emission measurements is now typically used for compliance 
determination in NESHAPs, with the limited exception of TEQ 
determination for dioxins and furans; and
    [cir] Remove the definition for ``startup'' that pertains to the 
former black liquor gasification system at Georgia-Pacific's facility 
in Big Island, Virginia.
     Corrected misspelling in 40 CFR 63.862(c).
     Revised multiple sections (40 CFR 63.863, 63.866, and 
63.867) to remove reference to the former smelters and former black 
liquor gasification system at Georgia-Pacific's facility in Big Island, 
Virginia.
     Revised the monitoring requirements section in 40 CFR 
63.864 to:
    [cir] Add reference to Performance Specification 1 (PS-1) in COMS 
monitoring provisions;
    [cir] Add IBR for bag leak detection systems;
    [cir] Specify written procedures for CMS recording frequency and 
reducing data into averages; and
    [cir] Clarify ongoing compliance provisions to address startup and 
shutdown periods when certain parameters cannot be met.
     Revised the performance test requirements section in 40 
CFR 63.865 to specify the conditions for conducting performance tests 
and to revise the ambient O2 concentration in Equations 7 
and 8 from 21 percent to 20.9 percent to bring 40 CFR part 63, subpart 
MM, in line with the rest of the NESHAPs.
     Revised the recordkeeping requirements section in 40 CFR 
63.866 to include the requirement to record information on failures to 
meet the applicable standard.
     Revised the terminology in the delegation of authority 
section in 40 CFR 63.868 to match the definitions in 40 CFR 63.90.
     Revised the General Provisions applicability table (Table 
1 to subpart MM of part 63) to align with those sections of the General 
Provisions that have been amended or reserved over time.

E. What compliance dates are we proposing?

    The compliance date for the revisions we are proposing here is 1 
year after the date of publication of the final rule in the Federal 
Register, with the exception of the following: (1) Facilities must 
conduct the first of the 5-year periodic performance tests within 3 
years of the effective date of the standards (that is, the date 3 years 
after the date of publication of the final rule in the Federal 
Register), and must conduct the subsequent periodic performance tests 
before renewing the facility's 40 CFR part 70 operating permit, but no 
longer than 5 years following the previous performance test; and (2) 
facilities must submit performance test data through the ERT within 60 
days after the date of completing each performance test.

V. Summary of Cost, Environmental, and Economic Impacts

A. What are the affected sources?

    There are currently 108 major source pulp and paper mills operating 
in the United States that conduct chemical recovery combustion 
operations, including 97 kraft pulp mills, 1 soda pulp mill, 3 sulfite 
pulp mills, and 7 stand-alone semichemical pulp mills. The 40 CFR part 
63, subpart MM, affected source regulated at kraft or soda pulp mills 
is each existing chemical recovery system, defined as all existing DCE 
and NDCE recovery furnaces, SDTs, and lime kilns. The DCE recovery 
furnace system is defined as the DCE recovery furnace and any BLO 
system, if present, at the pulp mill. New affected sources at kraft or 
soda pulp mills include each new NDCE or DCE recovery furnace and 
associated SDT, and each new lime kiln. Subpart MM affected sources 
also include each new or existing chemical recovery combustion unit 
located at a sulfite pulp

[[Page 97082]]

mill or at a stand-alone semichemical pulp mill.

B. What are the air quality impacts?

    At the current level of control, emissions of HAPs (HAP metals, 
acid gases, and gaseous organic HAP) are approximately 11,600 tpy. 
Current emissions of PM (a surrogate pollutant for HAP metals) and TRS 
(emitted by the same mechanism as gaseous organic HAP) are 
approximately 23,200 tpy and 3,600 tpy, respectively.
    The proposed amendments will require an estimated 108 mills to 
conduct periodic testing for their chemical recovery combustion 
operations, 96 mills equipped with ESP controls to meet more stringent 
opacity limits and monitoring allowances and conduct ESP parameter 
monitoring, and all 108 major sources with equipment subject to the 40 
CFR part 63, subpart MM standards to operate without the SSM exemption. 
The EPA estimates that the proposed changes to the opacity limits and 
monitoring allowances will reduce PM emissions by approximately 235 tpy 
and PM2.5 emissions by approximately 112 tpy. We were unable 
to quantify the specific emissions reductions associated with periodic 
emissions testing or eliminating the SSM exemption, and we expect no 
emissions reductions with ESP parameter monitoring. However, periodic 
testing will tend to reduce emissions by providing incentive for 
facilities to maintain their control systems and make periodic 
adjustments to ensure peak performance. Eliminating the SSM exemption 
will reduce emissions by requiring facilities to meet the applicable 
standard during SSM periods.
    Indirect or secondary air emissions impacts are impacts that would 
result from the increased electricity usage associated with the 
operation of control devices (i.e., increased secondary emissions of 
criteria pollutants from power plants). Energy impacts consist of the 
electricity and steam needed to operate control devices and other 
equipment that would be required under this proposed rule. The EPA 
estimates that the proposed changes to the opacity limits and 
monitoring allowances will result in energy impacts of 106,000 million 
British thermal units per year and criteria pollutant emissions of 29 
tpy (which includes PM, carbon monoxide, nitrogen oxides, and sulfur 
dioxide). The EPA expects no secondary air emissions impacts or energy 
impacts from the other proposed requirements.
    Section IV.C of this preamble presents estimates of the air quality 
impacts associated with the regulatory options that were not selected 
for inclusion in this proposed rule. For further information, see the 
memorandum titled, Costs/Impacts of the Subpart MM Residual Risk and 
Technology Review, in the docket for this action.

C. What are the cost impacts?

    Subpart MM of 40 CFR part 63 mills will incur costs to meet more 
stringent opacity limits and monitoring allowances, conduct periodic 
testing, and perform new ESP parameter monitoring. Costs associated 
with elimination of the startup and shutdown exemption were estimated 
as part of the reporting and recordkeeping costs and include time for 
re-evaluating previously developed SSM record systems. The EPA 
estimates the nationwide capital costs associated with the new testing 
and monitoring requirements to be $48 million. The EPA estimates the 
total nationwide annualized costs associated with these new 
requirements to be $13 million per year. Section IV.C of this preamble 
presents cost estimates associated with the regulatory options that 
were not selected for inclusion in this rule. For further information, 
see the memorandum titled Costs/Impacts of the Subpart MM Residual Risk 
and Technology Review, in the docket for this action.

D. What are the economic impacts?

    The economic impact analysis is designed to inform decision makers 
about the potential economic consequences of a regulatory action. For 
the current proposal, the EPA performed a partial-equilibrium analysis 
of national pulp and paper product markets to estimate potential paper 
product market and consumer and producer welfare impacts of the 
proposed regulatory options.
    Across proposed regulatory options, the EPA estimates market-level 
changes in the paper and paperboard markets to be insignificant. For 
the proposed option, the EPA predicts national-level weighted average 
paper and paperboard prices to increase about 0.01 percent, but 
predicts total quantities to decrease less than 0.01 percent.
    In addition, the EPA performed a screening analysis for impacts on 
small businesses by comparing estimated annualized engineering 
compliance costs at the firm-level to firm sales. The screening 
analysis found that the ratio of compliance cost to firm revenue falls 
below 1-percent for the three small companies likely to be affected by 
the proposal. For small firms, the minimum and maximum cost-to-sales 
ratios are less than 1 percent.
    More information and details of this analysis is provided in the 
technical document titled Economic Impact Analysis for Proposed 
Revisions to the National Emissions Standards for Hazardous Air 
Pollutants, Subpart MM, for the Pulp and Paper Industry, which is 
available in the docket for this proposed rule (Docket ID No. EPA-HQ-
OAR-2014-0741).

E. What are the benefits?

    The EPA estimates the proposed changes to the opacity limits and 
monitoring allowances at the 16 impacted mills will reduce PM emissions 
by approximately 235 tpy and PM2.5 emissions by 
approximately 112 tpy. Because these proposed amendments are not 
considered economically significant, as defined by Executive Order 
12866, we did not monetize the benefits of reducing these emissions. 
This does not mean that there are no benefits associated with the 
reduction in metal HAPs from this rule. We expect that these avoided 
emissions will reduce health effects associated with exposure to air 
pollution, and we provide below a qualitative description of benefits 
associated with reducing PM2.5. In addition, we anticipate 
the specific control technologies associated with these proposed 
amendments will result in minor disbenefits from additional energy 
consumption.
    Directly emitted particles are precursors to secondary formation of 
PM2.5. Controls installed to reduce HAP emissions would also 
reduce ambient concentrations of PM2.5. Reducing exposure to 
PM2.5 is associated with significant human health benefits, 
including avoiding mortality and morbidity from cardiovascular and 
respiratory illnesses. Researchers have associated PM2.5 
exposure with adverse health effects in numerous toxicological, 
clinical, and epidemiological studies (U.S. EPA, 2009).\43\ When 
adequate data and resources are available and a regulatory impact 
analysis is required, the EPA generally quantifies several health 
effects associated with exposure to PM2.5 (e.g., U.S. EPA, 
2012).\44\ These

[[Page 97083]]

health effects include premature mortality for adults and infants, 
cardiovascular morbidities such as heart attacks, hospital admissions, 
and respiratory morbidities such as asthma attacks, acute bronchitis, 
hospital and emergency department visits, work loss days, restricted 
activity days, and respiratory symptoms. The scientific literature also 
suggests that exposure to PM2.5 is associated with adverse 
effects on birth weight, pre-term births, pulmonary function, and other 
cardiovascular and respiratory effects (U.S. EPA, 2009), but the EPA 
has not quantified these impacts in its benefits analyses.
---------------------------------------------------------------------------

    \43\ U.S. Environmental Protection agency (U.S. EPA). 2009. 
Integrated Science Assessment for Particulate Matter (Final Report). 
EPA-600-R-08-139F. National Center for Environmental Assessment--RTP 
Division. Available on the Internet at https://cfpub.epa.gov/ncea/risk/recordisplay.cfm?deid=216546.
    \44\ U.S. Environmental Protection Agency (U.S. EPA). 2012. 
Regulatory Impact Analysis for the Final Revisions to the National 
Ambient Air Quality Standards for Particulate Matter. Office of Air 
and Radiation, Research Triange Park, NC. Available on the Internet 
at https://www3.epa.gov/thn/ecas/regdata/RIAs/finalria.pdf and 
https://www3.epa.gov/ttnecas1/regdata/RIAs/PMRIACombinedFile_Bookmarked.pdf.
---------------------------------------------------------------------------

VI. Request for Comments

    We solicit comments on all aspects of this proposed action. In 
addition to general comments on this proposed action, we are also 
interested in additional data that may improve the risk assessments and 
other analyses. We are specifically interested in receiving any 
improvements to the data used in the site-specific emissions profiles 
used for risk modeling. Such data should include supporting 
documentation in sufficient detail to allow characterization of the 
quality and representativeness of the data or information. Section VII 
of this preamble provides more information on submitting data.

VII. Submitting Data Corrections

    The site-specific emissions profiles used in the source category 
risk and demographic analyses and instructions are available for 
download on the RTR Web site at: http://www3.epa.gov/ttn/atw/rrisk/rtrpg.html. The data files include detailed information for each HAP 
emissions release point for the facilities in the source category.
    If you believe that 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 
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 site, complete the following steps:
    1. Within this downloaded file, enter suggested revisions to the 
data fields appropriate for that information.
    2. Fill in the commenter information fields for each suggested 
revision (i.e., commenter name, commenter organization, commenter email 
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-2014-0741 (through one of the methods 
described in the ADDRESSES section of this preamble).
    5. If you are providing comments on a single facility or multiple 
facilities, you need only submit one file for all facilities. The file 
should contain all suggested changes for all sources at that facility. 
We request that all data revision comments be submitted in the form of 
updated Microsoft[supreg] Excel files that are generated by the 
Microsoft[supreg] Access file. These files are provided on the RTR Web 
site at: http://www3.epa.gov/ttn/atw/rrisk/rtrpg.html.

VIII. Statutory and Executive Order Reviews

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

A. Executive Order 12866: Regulatory Planning and Review and Executive 
Order 13563: Improving Regulation and Regulatory Review

    This action is not a significant regulatory action and was 
therefore not submitted to OMB for review.

B. Paperwork Reduction Act (PRA)

    The information collection activities in this proposed rule have 
been submitted for approval to OMB under the PRA. The ICR document that 
the EPA prepared has been assigned EPA ICR number 1805.08. You can find 
a copy of the ICR in the docket for this rule, and it is briefly 
summarized here.
    The information collection requirements are not enforceable until 
OMB approves them. The information requirements are based on 
notification, recordkeeping, and reporting requirements in the NESHAP 
General Provisions (40 CFR part 63, subpart A), which are essential in 
determining compliance and mandatory for all operators subject to 
national emissions standards. These recordkeeping and reporting 
requirements are specifically authorized by CAA section 114 (42 U.S.C. 
7414). All information submitted to the EPA pursuant to the 
recordkeeping and reporting requirements for which a claim of 
confidentiality is made is safeguarded according to Agency policies set 
forth in 40 CFR part 2, subpart B.
    We are proposing changes to the paperwork requirements for 40 CFR 
part 63, subpart MM, in the form of eliminating the SSM reporting and 
SSM plan requirements, adding periodic emissions testing for selected 
process equipment, revising opacity monitoring provisions, adding 
parameter monitoring for ESPs, changing the frequency of all excess 
emissions reports to semiannual, and requiring electronic submittal of 
all compliance reports (including performance test reports).
    Respondents/affected entities: Respondents include chemical pulp 
mills operating equipment subject to 40 CFR part 63, subpart MM.
    Respondent's obligation to respond: Mandatory (authorized by 
section 114 of the CAA).
    Estimated number of respondents: 108.
    Frequency of response: The frequency of responses varies depending 
on the burden item. Responses include initial notifications, reports of 
periodic performance tests, and semiannual compliance reports.
    Total estimated burden: The annual recordkeeping and reporting 
burden for this information collection, averaged over the first 3 years 
of this ICR, is estimated to total 139,600 labor hours per year. Burden 
is defined at 5 CFR 1320.3(b).
    Total estimated cost: $17.7 million per year, including $14.4 
million per year in labor costs and $3.29 million per year in 
annualized capital and operation and maintenance costs.
    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. The OMB control numbers for the 
EPA's regulations in 40 CFR are listed in 40 CFR part 9.
    Submit your comments on the Agency's need for this information, the 
accuracy of the provided burden estimates, and any suggested methods 
for minimizing respondent burden, to the EPA using the docket 
identified at the beginning of this rule. You may also send your ICR-
related comments to OMB's Office of Information and Regulatory Affairs 
via email to OIRA_submission@omb.eop.gov, Attention: Desk Officer for 
the EPA. Since OMB is required to make a decision concerning the ICR 
between 30 and 60 days after receipt, OMB must receive comments no 
later than January 30, 2017. The EPA will respond to any ICR-related 
comments in the final rule.

[[Page 97084]]

C. Regulatory Flexibility Act (RFA)

    I certify that this action will not have a significant economic 
impact on a substantial number of small entities under the RFA. In 
making this determination, the impact of concern is any significant 
adverse economic impact on small entities. An agency may certify that a 
rule will not have a significant economic impact on a substantial 
number of small entities if the rule relieves regulatory burden, has no 
net burden or otherwise has a positive economic effect on the small 
entities subject to the rule. The EPA estimates that all affected small 
entities will have annualized costs of less than 1 percent of their 
sales. We have, therefore, concluded that this action will have no net 
regulatory burden for all directly regulated small entities. For more 
information on the small entity impacts associated with this proposed 
rule, please refer to the Economic Impact and Small Business Analyses 
in the public docket.

D. Unfunded Mandates Reform Act (UMRA)

    This action does not contain an unfunded mandate of $100 million or 
more as described in UMRA, 2 U.S.C. 1531-1538, and does not 
significantly or uniquely affect small governments. The action imposes 
no enforceable duty on any state, local, or tribal governments or the 
private sector.

E. Executive Order 13132: Federalism

    This action does not have federalism implications. It will not have 
substantial direct effects on the states, on the relationship between 
the national government and the states, or on the distribution of power 
and responsibilities among the various levels of government.

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

    This action does not have tribal implications as specified in 
Executive Order 13175. It will not have substantial direct effects on 
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. This rule imposes requirements on owners and 
operators of kraft, soda, sulfite, and stand-alone semichemical pulp 
mills and not tribal governments. The EPA does not know of any pulp 
mills owned or operated by Indian tribal governments, or located within 
tribal lands. However, if there are any, the effect of this rule on 
communities of tribal governments would not be unique or 
disproportionate to the effect on other communities. Thus, Executive 
Order 13175 does not apply to this action.

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

    This action is not subject to Executive Order 13045 because it is 
not economically significant as defined in Executive Order 12866, and 
because the EPA does not believe the environmental health or safety 
risks addressed by this action present a disproportionate risk to 
children. This action's health and risk assessments are contained in 
sections III and IV of this preamble and further documented in the risk 
report, titled Residual Risk Assessment for Pulp Mill Combustion 
Sources in Support of the December 2016 Risk and Technology Review 
Proposed Rule, in the docket for this action.

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

    This action is not subject to Executive Order 13211, because it is 
not a significant regulatory action under Executive Order 12866.

I. National Technology Transfer and Advancement Act (NTTAA) and 1 CFR 
part 51

    This action involves technical standards. While the EPA identified 
ASTM D6784-02 (Reapproved 2008), ``Standard Test Method for Elemental, 
Oxidized, Particle-Bound and Total Mercury Gas Generated from Coal-
Fired Stationary Sources (Ontario Hydro Method)'' as being potentially 
applicable, the Agency does not propose to use it. The use of this 
voluntary consensus standard would be impractical because this standard 
is only acceptable as an alternative to the portion of Method 29 for 
mercury, and mercury is not regulated under 40 CFR part 63, subpart MM.

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

    The EPA believes that this action will not have potential 
disproportionately high and adverse human health or environmental 
effects on minority populations, low-income populations, and/or 
indigenous peoples, as specified in Executive Order 12898 (59 FR 7629, 
February 16, 1994). The documentation for this decision is contained in 
section IV.B of this preamble and the technical report titled Risk and 
Technology Review--Analysis of Socio-Economic Factors for Populations 
Living Near Pulp Mill Combustion Sources, which is located in the 
public docket for this action.
    We examined the potential for any EJ issues that might be 
associated with the source category, by performing a demographic 
analysis of the population close to the facilities. In this analysis, 
we evaluated the distribution of HAP-related cancer and non-cancer 
risks from the 40 CFR part 63, subpart MM source category across 
different social, demographic, and economic groups within the 
populations living near facilities identified as having the highest 
risks. The methodology and the results of the demographic analyses are 
included in a technical report, Risk and Technology Review--Analysis of 
Socio-Economic Factors for Populations Living Near Pulp Mill Combustion 
Sources, available in the docket for this action.
    The results of the 40 CFR part 63, subpart MM source category 
demographic analysis indicate that emissions from the source category 
expose approximately 7,600 people to a cancer risk at or above 1-in-1 
million and no one exposed to a chronic non-cancer TOSHI greater than 
1. The specific demographic results indicate that the percentage of the 
population potentially impacted by emissions is greater than its 
corresponding national percentage for the minority population (33 
percent for the source category compared to 28 percent nationwide), the 
African American population (28 percent for the source category 
compared to 13 percent nationwide) and for the population over age 25 
without a high school diploma (18 percent for the source category 
compared to 15 percent nationwide). The proximity results (irrespective 
of risk) indicate that the population percentages for certain 
demographic categories within 5 km of source category emissions are 
greater than the corresponding national percentage for those same 
demographics. The following demographic percentages for populations 
residing within close proximity to facilities with pulp mill combustion 
sources are higher than the corresponding nationwide percentage: 
African American, ages 65 and up, over age 25 without a high school 
diploma, and below the poverty level.
    The risks due to HAP emissions from this source category are low 
for all populations (e.g., inhalation cancer risks are less than 4-in-1 
million for all populations and non-cancer hazard indices are less than 
1). Furthermore, we do not expect this proposal to

[[Page 97085]]

achieve significant reductions in HAP emissions. Therefore, we conclude 
that this proposal will not have disproportionately high and adverse 
human health or environmental effects on minority or low-income 
populations because it does not affect the level of protection provided 
to human health or the environment. However, this proposal, if 
finalized, will provide additional benefits to these demographic groups 
by improving the compliance, monitoring, and implementation of the 
NESHAP.

List of Subjects in 40 CFR Part 63

    Environmental protection, Administrative practice and procedure, 
Air pollution control, Hazardous substances, Incorporation by 
reference, Intergovernmental relations, Pulp and paper mills, Reporting 
and recordkeeping requirements.

    Dated: December 13, 2016.
Gina McCarthy,
Administrator.
    For the reasons set out in the preamble, title 40, chapter I, part 
63 of the Code of Federal Regulations is proposed to be amended as 
follows:

PART 63--[AMENDED]

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

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

Subpart A--[Amended]

0
2. Section 63.14 is amended by revising paragraph (m)(3) to read as 
follows:

Sec.  63.14   Incorporations by reference.

* * * * *
    (m) * * *
    (3) EPA-454/R-98-015, Office of Air Quality Planning and Standards 
(OAQPS), Fabric Filter Bag Leak Detection Guidance, September 1997, IBR 
approved for Sec. Sec.  63.548(e), 63.864(e), 63.7525(j), 63.8450(e), 
63.8600(e), and 63.11224(f).

Subpart MM--[Amended]

0
3. Section 63.860 is amended by revising paragraphs (b)(5) and (7) and 
adding paragraph (d) to read as follows:

Sec.  63.860   Applicability and designation of affected source.

* * * * *
    (b) * * *
    (5) Each new or existing sulfite combustion unit located at a 
sulfite pulp mill, except such existing units at Cosmo Specialty 
Fibers' Cosmopolis, Washington facility (Emission Unit no. AP-10).
* * * * *
    (7) The requirements of the alternative standard in Sec.  63.862(d) 
apply to the hog fuel dryer at Cosmo Specialty Fibers' Cosmopolis, 
Washington facility (Emission Unit no. HD-14).
* * * * *
    (d) At all times, the owner or operator must 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. 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 the applicable standard have been achieved. Determination 
of whether a source is operating in compliance with operation and 
maintenance requirements 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.
0
4. Section 63.861 is amended by:
0
a. Removing the definitions for ``Black liquor gasification'' and 
``Startup'';
0
b. Revising the definitions for ``Hazardous air pollutants (HAP) 
metals,'' ``Hog fuel dryer,'' ``Kraft recovery furnace,'' 
``Modification,'' ``Particulate matter (PM),'' ``Recovery furnace,'' 
``Semichemical combustion unit,'' ``Soda recovery furnace,'' and 
``Total hydrocarbons (THC).''
    The revisions read as follows:

Sec.  63.861   Definitions.

* * * * *
    Hazardous air pollutants (HAP) metals means the sum of all 
emissions of antimony, arsenic, beryllium, cadmium, chromium, cobalt, 
lead, manganese, mercury, nickel, and selenium as measured by EPA 
Method 29 (40 CFR part 60, appendix A-8).
    Hog fuel dryer means the equipment that combusts fine particles of 
wood waste (hog fuel) in a fluidized bed and directs the heated exhaust 
stream to a rotary dryer containing wet hog fuel to be dried prior to 
combustion in the hog fuel boiler at Cosmo Specialty Fibers' 
Cosmopolis, Washington facility. The hog fuel dryer at Cosmo Specialty 
Fibers' Cosmopolis, Washington facility is Emission Unit no. HD-14.
* * * * *
    Kraft recovery furnace means a recovery furnace that is used to 
burn black liquor produced by the kraft pulping process, as well as any 
recovery furnace that burns black liquor produced from both the kraft 
and semichemical pulping processes, and includes the direct contact 
evaporator, if applicable.
* * * * *
    Modification means, for the purposes of Sec.  
63.862(a)(1)(ii)(E)(1), any physical change (excluding any routine part 
replacement or maintenance) or operational change that is made to the 
air pollution control device that could result in an increase in PM 
emissions.
* * * * *
    Particulate matter (PM) means total filterable particulate matter 
as measured by EPA Method 5 (40 CFR part 60, appendix A-3), EPA Method 
17 (Sec.  63.865(b)(1)) (40 CFR part 60, appendix A-6), or EPA Method 
29 (40 CFR part 60, appendix A-8).
* * * * *
    Recovery furnace means an enclosed combustion device where 
concentrated black liquor produced by the kraft or soda pulping process 
is burned to recover pulping chemicals and produce steam.
* * * * *
    Semichemical combustion unit means any equipment used to combust or 
pyrolyze black liquor at stand-alone semichemical pulp mills for the 
purpose of chemical recovery.
* * * * *
    Soda recovery furnace means a recovery furnace used to burn black 
liquor produced by the soda pulping process and includes the direct 
contact evaporator, if applicable.
* * * * *
    Total hydrocarbons (THC) means the sum of organic compounds 
measured as carbon using EPA Method 25A (40 CFR part 60, appendix A-7).
0
5. Section 63.862 is amended by revising paragraphs (c)(1) and (d) to 
read as follows:

Sec.  63.862   Standards.

* * * * *
    (c) Standards for gaseous organic HAP. (1) The owner or operator of 
any new recovery furnace at a kraft or soda pulp mill must ensure that 
the concentration or gaseous organic HAP, as measured by methanol, 
discharged to the atmosphere is no greater than 0.012 kg/Mg (0.025 lb/
ton) of black liquor solids fired.
* * * * *
    (d) Alternative standard. As an alternative to meeting the 
requirements of paragraph (a)(2) of this section, the owner or operator 
of the existing hog

[[Page 97086]]

fuel dryer at Cosmo Specialty Fibers' Cosmopolis, Washington facility 
(Emission Unit no. HD-14) must ensure that the mass of PM in the 
exhaust gases discharged to the atmosphere from the hog fuel dryer is 
less than or equal to 4.535 kilograms per hour (kg/hr) (10.0 pounds per 
hour (lb/hr)).
0
6. Section 63.863 is amended by revising paragraph (c) to read as 
follows:

Sec.  63.863   Compliance dates.

* * * * *
    (c) The owner or operator of an existing or new affected source or 
process unit must comply with the revised requirements published on 
[insert date of publication of final rule in the Federal Register] no 
later than [insert date 1 year after date of publication of final rule 
in the Federal Register], with the exception of the following:
    (1) The first of the 5-year periodic performance tests must be 
conducted within 3 years of the effective date of the revised 
standards, by [insert date 3 years after date of publication of final 
rule in the Federal Register], and thereafter before renewing the 
facility's 40 CFR part 70 operating permit, but no longer than 5 years 
following the previous performance test; and
    (2) The date to submit performance test data through the ERT is 
within 60 days after the date of completing each performance test.
0
7. Section 63.864 is revised to read as follows:

Sec.  63.864   Monitoring requirements.

    (a)-(c) [Reserved]
    (d) Continuous opacity monitoring system (COMS). The owner or 
operator of each affected kraft or soda recovery furnace or lime kiln 
equipped with an ESP must install, calibrate, maintain, and operate a 
COMS in accordance with Performance Specification 1 (PS-1) in appendix 
B to 40 CFR part 60 and the provisions in Sec. Sec.  63.6(h) and 63.8 
and paragraphs (d)(1) through (5) of this section.
    (1)-(2) [Reserved]
    (3) As specified in Sec.  63.8(c)(4)(i), each COMS must complete a 
minimum of one cycle of sampling and analyzing for each successive 10-
second period and one cycle of data recording for each successive 6-
minute period.
    (4) As specified in Sec.  63.8(g)(2), each 6-minute COMS data 
average must be calculated as the average of 36 or more data points, 
equally spaced over each 6-minute period.
    (5) As specified in Sec.  63.8(g)(4), each 6-minute COMS data 
average should be rounded to the nearest 1-percent opacity.
    (e) Continuous parameter monitoring system (CPMS). For each CPMS 
required in this section, the owner or operator of each affected source 
or process unit must meet the requirements in paragraphs (e)(1) through 
(14) of this section.
    (1) For any kraft or soda recovery furnace or lime kiln using an 
ESP emission control device, the owner or operator must use the 
continuous parameter monitoring devices specified in paragraphs 
(e)(1)(i) and (ii) of this section to determine and record parameters 
at least once every successive 15-minute period.
    (i) A monitoring device for the continuous measurement of the 
secondary voltage of each ESP collection field.
    (ii) A monitoring device for the continuous measurement of the 
secondary current of each ESP collection field.
    (iii) Total secondary power may be calculated as the product of the 
secondary voltage and secondary current measurements for each ESP 
collection field and used to demonstrate compliance as an alternative 
to the secondary voltage and secondary current measurements.
    (2) For any kraft or soda recovery furnace or lime kiln using an 
ESP followed by a wet scrubber, the owner or operator must use the 
continuous parameter monitoring devices specified in paragraphs (e)(1) 
and (10) of this section. The opacity monitoring system specified in 
paragraph (d) of this section is not required for combination ESP/wet 
scrubber control device systems.
    (3)-(9) [Reserved]
    (10) The owner or operator of each affected kraft or soda recovery 
furnace, kraft or soda lime kiln, sulfite combustion unit, or kraft or 
soda smelt dissolving tank equipped with a wet scrubber must install, 
calibrate, maintain, and operate a CPMS that can be used to determine 
and record the pressure drop across the scrubber and the scrubbing 
liquid flow rate at least once every successive 15-minute period using 
the procedures in Sec.  63.8(c), as well as the procedures in 
paragraphs (e)(10)(i) and (ii) of this section:
    (i) A monitoring device used for the continuous measurement of the 
pressure drop of the gas stream across the scrubber must be certified 
by the manufacturer to be accurate to within a gage pressure of 500 pascals (2 inches of water gage pressure); and
    (ii) A monitoring device used for continuous measurement of the 
scrubbing liquid flow rate must be certified by the manufacturer to be 
accurate within 5 percent of the design scrubbing liquid 
flow rate.
    (iii) As an alternative to pressure drop measurement under 
paragraph (e)(3)(i) of this section, a monitoring device for 
measurement of fan amperage may be used for smelt dissolving tank 
dynamic scrubbers that operate at ambient pressure or for low-energy 
entrainment scrubbers where the fan speed does not vary.
    (11) The owner or operator of each affected semichemical combustion 
unit equipped with an RTO must install, calibrate, maintain, and 
operate a CPMS that can be used to determine and record the operating 
temperature of the RTO at least once every successive 15-minute period 
using the procedures in Sec.  63.8(c). The monitor must compute and 
record the operating temperature at the point of incineration of 
effluent gases that are emitted using a temperature monitor accurate to 
within 1 percent of the temperature being measured.
    (12) The owner or operator of the affected hog fuel dryer at Cosmo 
Specialty Fibers' Cosmopolis, Washington facility (Emission Unit no. 
HD-14) must meet the requirements in paragraphs (e)(12)(i) through (xi) 
of this section for each bag leak detection system.
    (i) The owner or operator must install, calibrate, maintain, and 
operate each triboelectric bag leak detection system according to EPA-
454/R-98-015, ``Fabric Filter Bag Leak Detection Guidance'' 
(incorporated by reference--see Sec.  63.14). This document is 
available from the U.S. Environmental Protection Agency (U.S. EPA); 
Office of Air Quality Planning and Standards; Emissions, Monitoring and 
Analysis Division; Emission Measurement Center, MD-D205-02, Research 
Triangle Park, NC 27711. This document is also available on the EPA 
Technical Air Pollution Resources Emission Measurement Center Web page 
under Continuous Emission Monitoring. The owner or operator must 
install, calibrate, maintain, and operate other types of bag leak 
detection systems in a manner consistent with the manufacturer's 
written specifications and recommendations.
    (ii) The bag leak detection system must be certified by the 
manufacturer to be capable of detecting PM emissions at concentrations 
of 10 milligrams per actual cubic meter (0.0044 grains per actual cubic 
foot) or less.
    (iii) The bag leak detection system sensor must provide an output 
of relative PM loadings.
    (iv) The bag leak detection system must be equipped with a device 
to

[[Page 97087]]

continuously record the output signal from the sensor.
    (v) The bag leak detection system must be equipped with an audible 
alarm system that will sound automatically when an increase in relative 
PM emissions over a preset level is detected. The alarm must be located 
where it is easily heard by plant operating personnel.
    (vi) For positive pressure fabric filter systems, a bag leak 
detector must be installed in each baghouse compartment or cell.
    (vii) For negative pressure or induced air fabric filters, the bag 
leak detector must be installed downstream of the fabric filter.
    (viii) Where multiple detectors are required, the system's 
instrumentation and alarm may be shared among detectors.
    (ix) The baseline output must be established by adjusting the range 
and the averaging period of the device and establishing the alarm set 
points and the alarm delay time according to section 5.0 of the 
``Fabric Filter Bag Leak Detection Guidance'' (incorporated by 
reference--see Sec.  63.14).
    (x) Following initial adjustment of the system, the sensitivity or 
range, averaging period, alarm set points, or alarm delay time may not 
be adjusted except as detailed in the site-specific monitoring plan. In 
no case may the sensitivity be increased by more than 100 percent or 
decreased more than 50 percent over a 365-day period unless such 
adjustment follows a complete fabric filter inspection which 
demonstrates that the fabric filter is in good operating condition, as 
defined in section 5.2 of the ``Fabric Filter Bag Leak Detection 
Guidance,'' (incorporated by reference--see Sec.  63.14). Record each 
adjustment.
    (xi) The owner or operator must record the results of each 
inspection, calibration, and validation check.
    (13) The owner or operator of each affected source or process unit 
that uses an ESP, wet scrubber, RTO, or fabric filter may monitor 
alternative control device operating parameters subject to prior 
written approval by the Administrator. The request for approval must 
also include the manner in which the parameter operating limit is to be 
set.
    (14) The owner or operator of each affected source or process unit 
that uses an air pollution control system other than an ESP, wet 
scrubber, RTO, or fabric filter must provide to the Administrator an 
alternative monitoring request that includes the site-specific 
monitoring plan described in paragraph (a) of this section, a 
description of the control device, test results verifying the 
performance of the control device, the appropriate operating parameters 
that will be monitored, how the operating limit is to be set, and the 
frequency of measuring and recording to establish continuous compliance 
with the standards. The alternative monitoring request is subject to 
the Administrator's approval. The owner or operator of the affected 
source or process unit must install, calibrate, operate, and maintain 
the monitor(s) in accordance with the alternative monitoring request 
approved by the Administrator. The owner or operator must include in 
the information submitted to the Administrator proposed performance 
specifications and quality assurance procedures for the monitors. The 
Administrator may request further information and will approve 
acceptable test methods and procedures. The owner or operator must 
monitor the parameters as approved by the Administrator using the 
methods and procedures in the alternative monitoring request.
    (f) Data quality assurance. The owner or operator shall keep CMS 
data quality assurance procedures consistent with the requirements in 
Sec.  63.8(d)(1) and (2) on record for the life of the affected source 
or until the affected source is no longer subject to the provisions of 
this part, to be made available for inspection, upon request, by the 
Administrator. If the performance evaluation plan in Sec.  63.8(d)(2) 
is revised, the owner or operator shall keep previous (i.e., 
superseded) versions of the performance evaluation plan on record to be 
made available for inspection, upon request, by the Administrator, for 
a period of 5 years after each revision to the plan. The program of 
corrective action should be included in the plan required under Sec.  
63.8(d)(2).
    (g) Gaseous organic HAP. The owner or operator of each affected 
source or process unit complying with the gaseous organic HAP standard 
of Sec.  63.862(c)(1) through the use of an NDCE recovery furnace 
equipped with a dry ESP system is not required to conduct any 
continuous monitoring to demonstrate compliance with the gaseous 
organic HAP standard.
    (h) Monitoring data. As specified in Sec.  63.8(g)(5), monitoring 
data recorded during periods of unavoidable CMS breakdowns, out-of-
control periods, repairs, maintenance periods, calibration checks, and 
zero (low-level) and high level adjustments must not be included in any 
data average computed under this part.
    (i) [Reserved]
    (j) Determination of operating limits. (1) During the initial or 
periodic performance test required in Sec.  63.865, the owner or 
operator of any affected source or process unit must establish 
operating limits for the monitoring parameters in paragraphs (e)(1) and 
(2) and (e)(10) through (14) of this section, as appropriate; or
    (2) The owner or operator may base operating limits on values 
recorded during previous performance tests or conduct additional 
performance tests for the specific purpose of establishing operating 
limits, provided that test data used to establish the operating limits 
are or have been obtained using the test methods required in this 
subpart. The owner or operator of the affected source or process unit 
must certify that all control techniques and processes have not been 
modified subsequent to the testing upon which the data used to 
establish the operating parameter limits were obtained.
    (3) The owner or operator of an affected source or process unit may 
establish expanded or replacement operating limits for the monitoring 
parameters listed in paragraphs (e)(1) and (2) and (e)(10) through (14) 
of this section and established in paragraph (j)(1) or (2) of this 
section during subsequent performance tests using the test methods in 
Sec.  63.865.
    (4) The owner or operator of the affected source or process unit 
must continuously monitor each parameter and determine the arithmetic 
average value of each parameter during each performance test. Multiple 
performance tests may be conducted to establish a range of parameter 
values.
    (5) New, expanded, or replacement operating limits for the 
monitoring parameter values listed in paragraphs (e)(1) and (2) and 
(e)(10) through (14) of this section should be determined as described 
in paragraphs (j)(5)(i) through (iii) below.
    (i) The owner or operator of an affected source or process unit 
that uses a wet scrubber must set a minimum scrubber pressure drop 
operating limit as the average of the pressure drop values associated 
with each test run.
    (A) For a smelt dissolving tank dynamic wet scrubber operating at 
ambient pressure or for low-energy entrainment scrubbers where fan 
speed does not vary, the minimum fan amperage operating limit must be 
set as the average of the fan amperage values associated with each test 
run.
    (B) [Reserved]
    (ii) The owner operator of an affected source equipped with an ESP 
must set the minimum operating secondary current and secondary voltage 
as the

[[Page 97088]]

average of the values associated with each test run.
    (iii) The owner operator of an affected source equipped with an RTO 
must set the minimum operating temperature of the RTO as the average of 
the values associated with each test run.
    (6) [Reserved]
    (k) On-going compliance provisions. (1) Following the compliance 
date, owners or operators of all affected sources or process units are 
required to implement corrective action if the monitoring exceedances 
in paragraphs (k)(1)(ii) through (vii) of this section occur during 
times when spent pulping liquor or lime mud is fired (as applicable). 
Corrective action can include completion of transient startup and 
shutdown conditions as expediently as possible.
    (i) [Reserved]
    (ii) For a new or existing kraft or soda recovery furnace, kraft or 
soda smelt dissolving tank, kraft or soda lime kiln, or sulfite 
combustion unit equipped with a wet scrubber, when any 3-hour average 
parameter value is below the minimum operating limit established in 
paragraph (j) of this section, with the exception of pressure drop 
during periods of startup and shutdown.
    (iii) For a new or existing kraft or soda recovery furnace or lime 
kiln equipped with an ESP followed by a wet scrubber, when:
    (A) Any 3-hour average scrubber parameter value is below the 
minimum operating limit established in paragraph (j) of this section, 
with the exception of pressure drop during periods of startup and 
shutdown; and
    (B) Any 3-hour average ESP secondary voltage and secondary current 
(or total secondary power) values are below the minimum operating 
limits established during performance testing, with the exception of 
secondary current (or total secondary power) during periods of startup 
and shutdown.
    (iv) For a new or existing semichemical combustion unit equipped 
with an RTO, when any 1-hour average temperature falls below the 
minimum temperature operating limit established in paragraph (j) of 
this section.
    (v) For the hog fuel dryer at Cosmo Specialty Fibers' Cosmopolis, 
Washington facility (Emission Unit no. HD-14), when the bag leak 
detection system alarm sounds.
    (vi) For an affected source or process unit equipped with an ESP, 
wet scrubber, RTO, or fabric filter and monitoring alternative 
operating parameters established in paragraph (e)(13) of this section, 
when any 3-hour average value does not meet the operating limit 
established in paragraph (j) of this section.
    (vii) For an affected source or process unit equipped with an 
alternative air pollution control system and monitoring operating 
parameters approved by the Administrator as established in paragraph 
(e)(14) of this section, when any 3-hour average value does not meet 
the operating limit established in paragraph (j) of this section.
    (2) Following the compliance date, owners or operators of all 
affected sources or process units are in violation of the standards of 
Sec.  63.862 if the monitoring exceedances in paragraphs (k)(2)(i) 
through (ix) of this section occur during times when spent pulping 
liquor or lime mud is fired (as applicable):
    (i) For a new or existing kraft or soda recovery furnace equipped 
with an ESP, when opacity is greater than 20 percent for 2 percent or 
more of the operating time within any semiannual period;
    (ii) For a new or existing kraft or soda lime kiln equipped with an 
ESP, when opacity is greater than 20 percent for 1 percent or more of 
the operating time within any semiannual period;
    (iii) For a new or existing kraft or soda recovery furnace or lime 
kiln equipped with an ESP, when the ESP secondary voltage and secondary 
current (or total secondary power) averaged over the semiannual period 
are below the minimum operating limits established during the 
performance test, with the exception of secondary current (or total 
secondary power) during periods of startup and shutdown;
    (iv) For a new or existing kraft or soda recovery furnace, kraft or 
soda smelt dissolving tank, kraft or soda lime kiln, or sulfite 
combustion unit equipped with a wet scrubber, when six or more 3-hour 
average parameter values within any 6-month reporting period are below 
the minimum operating limits established in paragraph (j) of this 
section, with the exception of pressure drop during periods of startup 
and shutdown;
    (v) For a new or existing kraft or soda recovery furnace or lime 
kiln equipped with an ESP followed by a wet scrubber, when:
    (A) Six or more 3-hour average scrubber parameter values within any 
6-month reporting period are outside the range of values established in 
paragraph (j) of this section, with the exception of pressure drop 
during periods of startup and shutdown; and
    (B) Six or more 3-hour average ESP secondary voltage and secondary 
current (or total secondary power) values within any 6-month reporting 
period are below the minimum operating limits established during 
performance testing, with the exception of secondary current (or total 
secondary power) during periods of startup and shutdown;
    (vi) For a new or existing semichemical combustion unit equipped 
with an RTO, when any 3-hour average temperature falls below the 
temperature established in paragraph (j) of this section;
    (vii) For the hog fuel dryer at Cosmo Specialty Fibers' Cosmopolis, 
Washington facility (Emission Unit no. HD-14), when corrective action 
is not initiated within 1 hour of a bag leak detection system alarm and 
the alarm is engaged for more than 5 percent of the total operating 
time in a 6-month block reporting period. In calculating the operating 
time fraction, if inspection of the fabric filter demonstrates that no 
corrective action is required, no alarm time is counted; if corrective 
action is required, each alarm is counted as a minimum of 1 hour; if 
corrective action is not initiated within 1 hour, the alarm time is 
counted as the actual amount of time taken to initiate corrective 
action;
    (viii) For an affected source or process unit equipped with an ESP, 
wet scrubber, RTO, or fabric filter and monitoring alternative 
operating parameters established in paragraph (e)(13) of this section, 
when six or more 3-hour average values within any 6-month reporting 
period do not meet the operating limits established in paragraph (j) of 
this section; and
    (ix) For an affected source or process unit equipped with an 
alternative air pollution control system and monitoring operating 
parameters approved by the Administrator as established in paragraph 
(e)(14) of this section, when six or more 3-hour average values within 
any 6-month reporting period do not meet the operating limits 
established in paragraph (j) of this section.
    (3) [Reserved]
0
8. Section 63.865 is amended by revising the introductory text and 
paragraphs (b)(1) through (5), (c)(1), and (d)introductory text to read 
as follows:

Sec.  63.865   Performance test requirements and test methods.

    The owner or operator of each affected source or process unit 
subject to the requirements of this subpart is required to conduct an 
initial performance test and periodic performance tests using the test 
methods and procedures listed in Sec.  63.7 and paragraph (b) of this 
section. The owner or operator must conduct the first of the periodic 
performance tests within 3 years of the effective date of the

[[Page 97089]]

revised standards and thereafter before renewing their 40 CFR part 70 
operating permit but at intervals no longer than 5 years following the 
previous performance test. 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. Representative conditions exclude periods of 
startup and shutdown. The owner or operator may not conduct performance 
tests during periods of malfunction. The owner or operator must record 
the process information that is necessary to document operating 
conditions during the test and include in such record an explanation to 
support that such conditions represent normal operation. 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.
* * * * *
    (b) * * *
    (1) For purposes of determining the concentration or mass of PM 
emitted from each kraft or soda recovery furnace, sulfite combustion 
unit, smelt dissolving tank, lime kiln, or the hog fuel dryer at Cosmo 
Specialty Fibers' Cosmopolis, Washington facility (Emission Unit no. 
HD-14), Method 5 in appendix A-3 of 40 CFR part 60 or Method 29 in 
appendix A-8 of 40 CFR part 60 must be used, except that Method 17 in 
appendix A-6 of 40 CFR part 60 may be used in lieu of Method 5 or 
Method 29 if a constant value of 0.009 g/dscm (0.004 gr/dscf) is added 
to the results of Method 17, and the stack temperature is no greater 
than 205 [deg]C (400 [deg]F). For Methods 5, 29, and 17, the sampling 
time and sample volume for each run must be at least 60 minutes and 
0.90 dscm (31.8 dscf), and water must be used as the cleanup solvent 
instead of acetone in the sample recovery procedure.
    (2) For sources complying with Sec.  63.862(a) or (b), the PM 
concentration must be corrected to the appropriate oxygen concentration 
using Equation 7 of this section as follows:
[GRAPHIC] [TIFF OMITTED] TP30DE16.036

Where:

Ccorr = the measured concentration corrected for oxygen, 
g/dscm (gr/dscf);
Cmeas = the measured concentration uncorrected for 
oxygen, g/dscm (gr/dscf);

X = the corrected volumetric oxygen concentration (8 percent for 
kraft or soda recovery furnaces and sulfite combustion units and 10 
percent for kraft or soda lime kilns); and

Y = the measured average volumetric oxygen concentration.

    (3) Method 3A or 3B in appendix A-2 of 40 CFR part 60 must be used 
to determine the oxygen concentration. The voluntary consensus standard 
ANSI/ASME PTC 19.10-1981--Part 10 (incorporated by reference--see Sec.  
63.14) may be used as an alternative to using Method 3B. The gas sample 
must be taken at the same time and at the same traverse points as the 
particulate sample.
    (4) For purposes of complying with of Sec.  63.862(a)(1)(ii)(A), 
the volumetric gas flow rate must be corrected to the appropriate 
oxygen concentration using Equation 8 of this section as follows:
[GRAPHIC] [TIFF OMITTED] TP30DE16.037

Where:

Qcorr = the measured volumetric gas flow rate corrected 
for oxygen, dscm/min (dscf/min).

Qmeas = the measured volumetric gas flow rate uncorrected 
for oxygen, dscm/min (dscf/min).

Y = the measured average volumetric oxygen concentration.

X = the corrected volumetric oxygen concentration (8 percent for 
kraft or soda recovery furnaces and 10 percent for kraft or soda 
lime kilns).

    (5)(i) For purposes of selecting sampling port location and number 
of traverse points, Method 1 or 1A in appendix A-1 of 40 CFR part 60 
must be used;
    (ii) For purposes of determining stack gas velocity and volumetric 
flow rate, Method 2, 2A, 2C, 2D, or 2F in appendix A-1 of 40 CFR part 
60 or Method 2G in appendix A-2 of 40 CFR part 60 must be used;
    (iii) For purposes of conducting gas analysis, Method 3, 3A, or 3B 
in appendix A-2 of 40 CFR part 60 must be used. The voluntary consensus 
standard ANSI/ASME PTC 19.10-1981--Part 10 (incorporated by reference--
see Sec.  63.14) may be used as an alternative to using Method 3B; and
    (iv) For purposes of determining moisture content of stack gas, 
Method 4 in appendix A-3 of 40 CFR part 60 must be used.
* * * * *
    (c) * * *
    (1) The owner or operator complying through the use of an NDCE 
recovery furnace equipped with a dry ESP system is required to conduct 
periodic performance testing using Method 308 in appendix A of this 
part, as well as the methods listed in paragraphs (b)(5)(i) through 
(iv) of this section to demonstrate compliance with the gaseous organic 
HAP standard. The requirements and equations in paragraph (b)(2) of 
this section must be met and utilized, respectively.
* * * * *
    (d) The owner or operator seeking to determine compliance with the 
gaseous organic HAP standards in Sec.  63.862(c)(2) for semichemical 
combustion units must use Method 25A in appendix A-7 of 40 CFR part 60, 
as well as the methods listed in paragraphs (b)(5)(i) through (iv) of 
this section. The sampling time for each Method 25A run must be at 
least 60 minutes. The calibration gas for each Method 25A run must be 
propane.
* * * * *
0
9. Section 63.866 is revised to read as follows:

Sec.  63.866   Recordkeeping requirements.

    (a) [Reserved]
    (b) The owner or operator of an affected source or process unit 
must maintain records of any occurrence when corrective action is 
required under Sec.  63.864(k)(1), and when a violation is noted under 
Sec.  63.864(k)(2). Record the time corrective action was initiated and 
completed, and the corrective action taken.
    (c) In addition to the general records required by Sec.  
63.10(b)(2)(iii) and (vi) through (xiv), the owner or operator must 
maintain records of the information in paragraphs (c)(1) through (8) of 
this section:
    (1) Records of black liquor solids firing rates in units of Mg/d or 
ton/d for

[[Page 97090]]

all recovery furnaces and semichemical combustion units;
    (2) Records of CaO production rates in units of Mg/d or ton/d for 
all lime kilns;
    (3) Records of parameter monitoring data required under Sec.  
63.864, including any period when the operating parameter levels were 
inconsistent with the levels established during the performance test;
    (4) Records and documentation of supporting calculations for 
compliance determinations made under Sec.  63.865(a) through (d);
    (5) Records of parameter operating limits established for each 
affected source or process unit;
    (6) Records certifying that an NDCE recovery furnace equipped with 
a dry ESP system is used to comply with the gaseous organic HAP 
standard in Sec.  63.862(c)(1);
    (7) For the bag leak detection system on the hog fuel dryer fabric 
filter at Cosmo Specialty Fibers' Cosmopolis, Washington facility 
(Emission Unit no. HD-14), records of each alarm, the time of the 
alarm, the time corrective action was initiated and completed, and a 
brief description of the cause of the alarm and the corrective action 
taken; and
    (8) Records of the date, time, and duration of each startup and/or 
shutdown period, recording the periods when the affected source was 
subject to the standard applicable to startup and shutdown.
    (d)(1) In the event that an affected unit fails to meet an 
applicable standard, including any emission limit or operating limit, 
record the number of failures. For each failure record the date, start 
time, and duration of each failure along with a brief explanation of 
the cause.
    (2) For each failure to meet an applicable standard, record and 
retain a list of the affected sources or equipment, an estimate of the 
quantity of each regulated pollutant emitted over any emission limit 
and a description of the method used to estimate the emissions.
    (3) Record actions taken to minimize emissions in accordance with 
Sec.  63.860(d) and any corrective actions taken to return the affected 
unit to its normal or usual manner of operation.
0
10. Section 63.867 is revised to read as follows:

Sec.  63.867   Reporting requirements.

    (a) Notifications. (1) The owner or operator of any affected source 
or process unit must submit the applicable notifications from subpart A 
of this part, as specified in Table 1 of this subpart.
    (2) [Reserved]
    (3) In addition to the requirements in subpart A of this part, the 
owner or operator of the hog fuel dryer at Cosmo Specialty Fibers' 
Cosmopolis, Washington, facility (Emission Unit no. HD-14) must include 
analysis and supporting documentation demonstrating conformance with 
EPA guidance and specifications for bag leak detection systems in Sec.  
63.864(e)(12) in the Notification of Compliance Status.
    (b) Additional reporting requirements for HAP metals standards. (1) 
Any owner or operator of a group of process units in a chemical 
recovery system at a mill complying with the PM emissions limits in 
Sec.  63.862(a)(1)(ii) must submit the PM emissions limits determined 
in Sec.  63.865(a) for each affected kraft or soda recovery furnace, 
smelt dissolving tank, and lime kiln to the Administrator for approval. 
The emissions limits must be submitted as part of the notification of 
compliance status required under subpart A of this part.
    (2) Any owner or operator of a group of process units in a chemical 
recovery system at a mill complying with the PM emissions limits in 
Sec.  63.862(a)(1)(ii) must submit the calculations and supporting 
documentation used in Sec.  63.865(a)(1) and (2) to the Administrator 
as part of the notification of compliance status required under subpart 
A of this part.
    (3) After the Administrator has approved the emissions limits for 
any process unit, the owner or operator of a process unit must notify 
the Administrator before any of the actions in paragraphs (b)(3)(i) 
through (iv) of this section are taken:
    (i) The air pollution control system for any process unit is 
modified or replaced;
    (ii) Any kraft or soda recovery furnace, smelt dissolving tank, or 
lime kiln in a chemical recovery system at a kraft or soda pulp mill 
complying with the PM emissions limits in Sec.  63.862(a)(1)(ii) is 
shut down for more than 60 consecutive days;
    (iii) A continuous monitoring parameter or the value or range of 
values of a continuous monitoring parameter for any process unit is 
changed; or
    (iv) The black liquor solids firing rate for any kraft or soda 
recovery furnace during any 24-hour averaging period is increased by 
more than 10 percent above the level measured during the most recent 
performance test.
    (4) An owner or operator of a group of process units in a chemical 
recovery system at a mill complying with the PM emissions limits in 
Sec.  63.862(a)(1)(ii) and seeking to perform the actions in paragraph 
(b)(3)(i) or (ii) of this section must recalculate the overall PM 
emissions limit for the group of process units and resubmit the 
documentation required in paragraph (b)(2) of this section to the 
Administrator. All modified PM emissions limits are subject to approval 
by the Administrator.
    (c) Excess emissions report. The owner or operator must submit 
semiannual excess emissions reports containing the information 
specified in paragraphs (c)(1) through (5) of this section. The owner 
or operator must submit semiannual excess emission reports following 
the procedure specified in paragraph (d)(2) of this section.
    (1) If the total duration of excess emissions or process control 
system parameter exceedances for the reporting period is less than 1-
percent of the total reporting period operating time, and CMS downtime 
is less than 5-percent of the total reporting period operating time, 
only the summary report is required to be submitted in accordance with 
Sec.  63.10(e)(3)(vii). This report will be titled ``Summary Report--
Gaseous and Opacity Excess Emissions and Continuous Monitoring System 
Performance'' in accordance with Sec.  63.10(e)(3)(vi) and must contain 
the information required in Sec.  63.10(e)(3), as specified in 
paragraphs (c)(1)(i) through (x) of this section. When no exceedances 
of parameters have occurred, the owner or operator must submit the 
summary report stating that no excess emissions occurred during the 
reporting period. In addition to a statement verifying that no excess 
emissions occurred during the reporting period, this report must 
contain the information required in Sec.  63.10(e)(3) only as specified 
in paragraphs (c)(1)(i) through (x) of this section. The summary report 
must be submitted following the procedure specified in paragraph (d)(2) 
of this section.
    (i) The company name and address and name of the affected facility.
    (ii) Beginning and ending dates of the reporting period.
    (iii) An identification of each process unit with the corresponding 
air pollution control device, being included in the semiannual report, 
including the pollutants monitored at each process unit, and the total 
operating time for each process unit.
    (iv) An identification of the applicable emission limits, operating 
parameter limits, and averaging times.
    (v) An identification of the monitoring equipment used for each 
process unit and the corresponding model number.
    (vi) Date of the last CMS certification or audit.
    (vii) An emission data summary, including the total duration of 
excess

[[Page 97091]]

emissions (recorded in minutes for opacity and hours for gases), the 
duration of excess emissions expressed as a percent of operating time, 
and reason for the excess emissions (e.g., startup/shutdown, control 
equipment problems, other known reasons, or other unknown reasons).
    (viii) A CMS performance summary, including the total duration of 
CMS downtime, the duration of downtime expressed as a percent of 
operating time, and reason for the downtime (e.g., monitoring equipment 
malfunction, non-monitoring equipment malfunction, quality assurance, 
quality control calibrations, other known causes, or other unknown 
causes).
    (ix) A description of changes to CMS, processes, or controls since 
last reporting period.
    (x) A certification by a certifying official of truth, accuracy and 
completeness. This will state that, based on information and belief 
formed after reasonable inquiry, the statements and information in the 
document are true, accurate, and complete.
    (2) [Reserved]
    (3) If measured parameters meet any of the conditions specified in 
Sec.  63.864(k)(1) or (2), the owner or operator of the affected source 
must submit a semiannual report describing the excess emissions that 
occurred. If the total duration of monitoring exceedances for the 
reporting period is 1-percent or greater of the total reporting period 
operating time, or the total CMS downtime for the reporting period is 
5-percent or greater of the total reporting period operating time, or 
any violations according to Sec.  63.864(k)(2) occurred, information 
from both the summary report and the excess emissions and continuous 
monitoring system performance report must be submitted. This report 
will be titled ``Excess Emissions and Continuous Monitoring System 
Performance Report'' and must contain the information specified in 
paragraphs (c)(1)(i) through (x) of this section, in addition to the 
information required in Sec.  63.10(c)(5) through (14), as specified in 
paragraphs (c)(3)(i) through (vi) of this section. Reporting monitoring 
exceedances does not constitute a violation of the applicable standard 
unless the criteria in Sec.  63.864(k)(2) are reached.
    (i) An identification of the date and time identifying each period 
during which the CMS was inoperative except for zero (low-level) and 
high-level checks.
    (ii) An identification of the date and time identifying each period 
during which the CMS was out of control, as defined in Sec.  
63.8(c)(7).
    (iii) The specific identification of each period of excess 
emissions and parameter monitoring exceedances as described in 
paragraphs (c)(3)(iii)(A) through (C) of this section.
    (A) For opacity:
    (1) The total number of 6-minute averages in the reporting period 
(excluding process unit downtime).
    (2) The number of 6-minute averages in the reporting period removed 
due to invalid readings.
    (3) The number of 6-minute averages in the reporting period that 
exceeded the 20-percent opacity limit.
    (4) The percent of 6-minute averages in the reporting period that 
exceed the 20-percent opacity limit.
    (5) An identification of each exceedance by start time, date, and 
cause of exceedance (including startup/shutdown, control equipment 
problems, other known reasons, or other unknown reasons).
    (B) For ESP operating parameters:
    (1) The type of operating parameters monitored for compliance 
(total secondary power, or secondary voltage and secondary current).
    (2) The operating limits established during the performance test.
    (3) For systems only controlled with an ESP, the operating 
parameters averaged over the semiannual reporting period.
    (4) For combined ESP and wet scrubber control systems, the number 
of 3-hour ESP and wet scrubber parameter averages below the minimum 
operating limit established during the performance test.
    (5) An identification of each exceedance by start time, date, and 
cause of exceedance (including startup/shutdown, control equipment 
problems, other known reasons, or other unknown reasons).
    (C) For wet scrubber operating parameters:
    (1) The operating limits established during the performance test 
for scrubbing liquid flow rate and pressure drop across the scrubber 
(or fan amperage if used for smelt dissolving tank scrubbers).
    (2) The number of 3-hour wet scrubber parameter averages below the 
minimum operating limit established during the performance test, if 
applicable.
    (3) An identification of each exceedance by start time, date, and 
cause of exceedance (including startup/shutdown, control equipment 
problems, other known reasons, or other unknown reasons).
    (D) For RTO operating temperature:
    (1) The operating limit established during the performance test.
    (2) The number of 1-hour and 3-hour temperature averages below the 
minimum operating limit established during the performance test.
    (3) An identification of each exceedance by start time, date, and 
cause of exceedance including startup/shutdown, control equipment 
problems, other known reasons, or other unknown reasons).
    (iv) The nature and cause of any malfunction (if known).
    (v) The corrective action taken or preventative measures adopted.
    (vi) The nature of repairs and adjustments to the CMS that was 
inoperative or out of control.
    (4) If a source fails to meet an applicable standard, report such 
events in the semiannual excess emissions report. Report the number of 
failures to meet an applicable standard. For each instance, report the 
date, time and duration of each failure. For each failure the report 
must include a list of the affected sources or equipment, an estimate 
of the quantity of each regulated pollutant emitted over any emission 
limit, and a description of the method used to estimate the emissions.
    (5) The owner or operator of an affected source or process unit 
subject to the requirements of this subpart and subpart S of this part 
may combine excess emissions and/or summary reports for the mill.
    (d) Electronic reporting. (1) Within 60 days after the date of 
completing each performance test (as defined in Sec.  63.2) required by 
this subpart, the owner or operator must submit the results of the 
performance test following the procedure specified in either paragraph 
(d)(1)(i) or (ii) of this section.
    (i) For data collected using test methods supported by the EPA's 
Electronic Reporting Tool (ERT) as listed on the EPA's ERT Web site 
(https://www.epa.gov/electronic-reporting-air-emissions/electronic-reporting-tool-ert) at the time of the test, the owner or operator must 
submit the results of the performance test to the EPA via the 
Compliance and Emissions Data Reporting Interface (CEDRI). (CEDRI can 
be accessed through the EPA's Central Data Exchange (CDX) (https://cdx.epa.gov/).) Performance test data must be submitted in a file 
format generated through the use of the EPA's ERT or an alternate 
electronic file format consistent with the extensible markup language 
(XML) schema listed on the EPA's ERT Web site. If the owner or operator 
claims that some of the performance test information being submitted is 
confidential business information (CBI), the owner or operator must 
submit a complete file generated

[[Page 97092]]

through the use of the EPA's ERT or an alternate electronic file 
consistent with the XML schema listed on the EPA's ERT Web site, 
including information claimed to be CBI, on a compact disc, flash 
drive, or other commonly used electronic storage media to the EPA. The 
electronic media must be clearly marked as CBI and mailed to U.S. EPA/
OAPQS/CORE CBI Office, Attention: Group Leader, Measurement Policy 
Group, MD C404-02, 4930 Old Page Rd., Durham, NC 27703. The same ERT or 
alternate file with the CBI omitted must be submitted to the EPA via 
the EPA's CDX as described earlier in this paragraph (d)(1)(i).
    (ii) For data collected using test methods that are not supported 
by the EPA's ERT as listed on the EPA's ERT Web site at the time of the 
test, the owner or operator must attach an electronic copy of the 
complete performance test report containing the methods not included in 
the ERT in the attachment module of the ERT in portable document format 
(PDF) and submit the results of the performance test to the EPA via 
CEDRI.
    (2) The owner or operator must submit notification and semiannual 
reports to the EPA via the CEDRI. (CEDRI can be accessed through the 
EPA's CDX (https://cdx.epa.gov).) The owner or operator must use the 
appropriate electronic report in CEDRI for this subpart or an 
alternative electronic file format consistent with the XML schema 
listed on the CEDRI Web site (https://www.epa.gov/electronic-reporting-air-emissions/compliance-and-emissions-data-reporting-interface-cedri). 
If neither the reporting form nor the spreadsheet template specific to 
this subpart are available in CEDRI at the time that the report is due, 
you must upload an electronic copy of the report in CEDRI. Once the 
form or spreadsheet template has been available in CEDRI for at least 
90 calendar days, you must begin submitting all subsequent reports via 
CEDRI using the form or spreadsheet template. The reports must be 
submitted by the deadlines specified in this subpart, regardless of the 
method in which the reports are submitted.
0
11. Section 63.868 is amended by revising paragraphs (b)(2) through (4) 
to read as follows:

Sec.  63.868   Delegation of authority.

* * * * *
    (b) * * *
    (2) Approval of a major change to test method under Sec.  
63.7(e)(2)(ii) and (f) and as defined in Sec.  63.90.
    (3) Approval of a major change to monitoring under Sec.  63.8(f) 
and as defined in Sec.  63.90.
    (4) Approval of a major change to recordkeeping/reporting under 
Sec.  63.10(f) and as defined in Sec.  63.90.
0
12. Table 1 to subpart MM of part 63 is revised to read as follows:

                Table 1 to Subpart MM of Part 63--General Provisions Applicability to Subpart MM
----------------------------------------------------------------------------------------------------------------
   General provisions reference       Summary of requirements   Applies to subpart MM         Explanation
----------------------------------------------------------------------------------------------------------------
63.1(a)(1)........................  General applicability of    Yes..................  Additional terms defined
                                     the General Provisions.                            in Sec.   63.861; when
                                                                                        overlap between subparts
                                                                                        A and MM of this part,
                                                                                        subpart MM takes
                                                                                        precedence.
63.1(a)(2)-(14)...................  General applicability of    Yes..................
                                     the General Provisions.
63.1(b)(1)........................  Initial applicability       No...................  Subpart MM specifies the
                                     determination.                                     applicability in Sec.
                                                                                        63.860.
63.1(b)(2)........................  Title V operating permit--  Yes..................  All major affected
                                     see 40 CFR part 70.                                sources are required to
                                                                                        obtain a title V permit.
63.1(b)(3)........................  Record of the               No...................  All affected sources are
                                     applicability                                      subject to subpart MM
                                     determination.                                     according to the
                                                                                        applicability definition
                                                                                        of subpart MM.
63.1(c)(1)........................  Applicability of subpart A  Yes..................  Subpart MM clarifies the
                                     of this part after a                               applicability of each
                                     relevant standard has                              paragraph of subpart A
                                     been set.                                          of this part to sources
                                                                                        subject to subpart MM.
63.1(c)(2)........................  Title V permit requirement  Yes..................  All major affected
                                                                                        sources are required to
                                                                                        obtain a title V permit.
                                                                                        There are no area
                                                                                        sources in the pulp and
                                                                                        paper mill source
                                                                                        category.
63.1(c)(3)........................  [Reserved]................  No...................
63.1(c)(4)........................  Requirements for existing   Yes..................
                                     source that obtains an
                                     extension of compliance.
63.1(c)(5)........................  Notification requirements   Yes..................
                                     for an area source that
                                     increases HAP emissions
                                     to major source levels.
63.1(d)...........................  [Reserved]................  No...................
63.1(e)...........................  Applicability of permit     Yes..................
                                     program before a relevant
                                     standard has been set.
63.2..............................  Definitions...............  Yes..................  Additional terms defined
                                                                                        in Sec.   63.861; when
                                                                                        overlap between subparts
                                                                                        A and MM of this part
                                                                                        occurs, subpart MM takes
                                                                                        precedence.
63.3..............................  Units and abbreviations...  Yes..................
63.4..............................  Prohibited activities and   Yes..................
                                     circumvention.
63.5(a)...........................  Construction and            Yes..................
                                     reconstruction--applicabi
                                     lity.
63.5(b)(1)........................  Upon construction,          Yes..................
                                     relevant standards for
                                     new sources.
63.5(b)(2)........................  [Reserved]................  No...................
63.5(b)(3)........................  New construction/           Yes..................
                                     reconstruction.
63.5(b)(4)........................  Construction/               Yes..................
                                     reconstruction
                                     notification.
63.5(b)(5)........................  Construction/               Yes..................
                                     reconstruction compliance.
63.5(b)(6)........................  Equipment addition or       Yes..................
                                     process change.

[[Page 97093]]

 
63.5(c)...........................  [Reserved]................  No...................
63.5(d)...........................  Application for approval    Yes..................
                                     of construction/
                                     reconstruction.
63.5(e)...........................  Construction/               Yes..................
                                     reconstruction approval.
63.5(f)...........................  Construction/               Yes..................
                                     reconstruction approval
                                     based on prior State
                                     preconstruction review.
63.6(a)(1)........................  Compliance with standards   Yes..................
                                     and maintenance
                                     requirements--applicabili
                                     ty.
63.6(a)(2)........................  Requirements for area       Yes..................
                                     source that increases
                                     emissions to become major.
63.6(b)...........................  Compliance dates for new    Yes..................
                                     and reconstructed sources.
63.6(c)...........................  Compliance dates for        Yes, except for        Subpart MM specifically
                                     existing sources.           sources granted        stipulates the
                                                                 extensions under       compliance schedule for
                                                                 Sec.   63.863(c).      existing sources.
63.6(d)...........................  [Reserved]................  No...................
63.6(e)(1)(i).....................  General duty to minimize    No...................  See Sec.   63.860(d) for
                                     emissions.                                         general duty
                                                                                        requirement.
63.6(e)(1)(ii)....................  Requirement to correct      No...................
                                     malfunctions ASAP.
63.6(e)(1)(iii)...................  Operation and maintenance   Yes..................
                                     requirements enforceable
                                     independent of emissions
                                     limitations.
63.6(e)(2)........................  [Reserved]................  No...................
63.6(e)(3)........................  Startup, shutdown, and      No...................
                                     malfunction plan (SSMP).
63.6(f)(1)........................  Compliance with nonopacity  No...................
                                     emissions standards
                                     except during SSM.
63.6(f)(2)-(3)....................  Methods for determining     Yes..................
                                     compliance with
                                     nonopacity emissions
                                     standards.
63.6(g)...........................  Compliance with             Yes..................
                                     alternative nonopacity
                                     emissions standards.
63.6(h)(1)........................  Compliance with opacity     No...................
                                     and visible emissions
                                     (VE) standards except
                                     during SSM.
63.6(h)(2)-(9)....................  Compliance with opacity     Yes..................  Subpart MM does not
                                     and VE standards.                                  contain any opacity or
                                                                                        VE standards; however,
                                                                                        Sec.   63.864 specifies
                                                                                        opacity monitoring
                                                                                        requirements.
63.6(i)...........................  Extension of compliance     Yes..................
                                     with emission standards.
63.6(j)...........................  Exemption from compliance   Yes..................
                                     with emissions standards.
63.7(a)(1)........................  Performance testing         Yes..................
                                     requirements--applicabili
                                     ty.
63.7(a)(2)........................  Performance test dates....  Yes..................
63.7(a)(3)........................  Performance test requests   Yes..................
                                     by Administrator under
                                     CAA section 114.
63.7(a)(4)........................  Notification of delay in    Yes..................
                                     performance testing due
                                     to force majeure.
63.7(b)(1)........................  Notification of             Yes..................
                                     performance test.
63.7(b)(2)........................  Notification of delay in    Yes..................
                                     conducting a scheduled
                                     performance test.
63.7(c)...........................  Quality assurance program.  Yes..................
63.7(d)...........................  Performance testing         Yes..................
                                     facilities.
63.7(e)(1)........................  Conduct of performance      No...................  See Sec.   63.865.
                                     tests.
63.7(e)(2)-(3)....................  Conduct of performance      Yes..................
                                     tests.
63.7(e)(4)........................  Testing under section 114.  Yes..................
63.7(f)...........................  Use of an alternative test  Yes..................
                                     method.
63.7(g)...........................  Data analysis,              Yes..................
                                     recordkeeping, and
                                     reporting.
63.7(h)...........................  Waiver of performance       Yes..................  Sec.   63.865(c)(1)
                                     tests.                                             specifies the only
                                                                                        exemption from
                                                                                        performance testing
                                                                                        allowed under subpart
                                                                                        MM.
63.8(a)(1)........................  Monitoring requirements--   Yes..................  See Sec.   63.864.
                                     applicability.
63.8(a)(2)........................  Performance Specifications  Yes..................
63.8(a)(3)........................  [Reserved]................  No...................
63.8(a)(4)........................  Monitoring with flares....  No...................  The use of flares to meet
                                                                                        the standards in subpart
                                                                                        MM is not anticipated.
63.8(b)(1)........................  Conduct of monitoring.....  Yes..................  See Sec.   63.864.
63.8(b)(2)-(3)....................  Specific requirements for   Yes..................
                                     installing and reporting
                                     on monitoring systems.
63.8(c)(1)........................  Operation and maintenance   Yes..................  See Sec.   63.864.
                                     of CMS.
63.8(c)(1)(i).....................  General duty to minimize    No...................
                                     emissions and CMS
                                     operation.

[[Page 97094]]

 
63.8(c)(1)(ii)....................  Reporting requirements for  Yes..................
                                     SSM when action not
                                     described in SSMP.
63.8(c)(1)(iii)...................  Requirement to develop SSM  No...................
                                     plan for CMS.
63.8(c)(2)-(3)....................  Monitoring system           Yes..................
                                     installation.
63.8(c)(4)........................  CMS requirements..........  Yes..................
63.8(c)(5)........................  Continuous opacity          Yes..................
                                     monitoring system (COMS)
                                     minimum procedures.
63.8(c)(6)........................  Zero and high level         Yes..................
                                     calibration check
                                     requirements.
63.8(c)(7)-(8)....................  Out-of-control periods....  Yes..................
63.8(d)(1)-(2)....................  CMS quality control         Yes..................  See Sec.   63.864.
                                     program.
63.8(d)(3)........................  Written procedures for CMS  No...................  See Sec.   63.864(f).
63.8(e)(1)........................  Performance evaluation of   Yes..................
                                     CMS.
63.8(e)(2)........................  Notification of             Yes..................
                                     performance evaluation.
63.8(e)(3)........................  Submission of site-         Yes..................
                                     specific performance
                                     evaluation test plan.
63.8(e)(4)........................  Conduct of performance      Yes..................
                                     evaluation and
                                     performance evaluation
                                     dates.
63.8(e)(5)........................  Reporting performance       Yes..................
                                     evaluation results.
63.8(f)...........................  Use of an alternative       Yes..................
                                     monitoring method.
63.8(g)...........................  Reduction of monitoring     Yes..................
                                     data.
63.9(a)...........................  Notification requirements-- Yes..................
                                     applicability and general
                                     information.
63.9(b)...........................  Initial notifications.....  Yes..................
63.9(c)...........................  Request for extension of    Yes..................
                                     compliance.
63.9(d)...........................  Notification that source    Yes..................
                                     subject to special
                                     compliance requirements.
63.9(e)...........................  Notification of             Yes..................
                                     performance test.
63.9(f)...........................  Notification of opacity     Yes..................  Subpart MM does not
                                     and VE observations.                               contain any opacity or
                                                                                        VE standards; however,
                                                                                        Sec.   63.864 specifies
                                                                                        opacity monitoring
                                                                                        requirements.
63.9(g)(1)........................  Additional notification     Yes..................
                                     requirements for sources
                                     with CMS.
63.9(g)(2)........................  Notification of compliance  Yes..................  Subpart MM does not
                                     with opacity emissions                             contain any opacity or
                                     standard.                                          VE emissions standards;
                                                                                        however, Sec.   63.864
                                                                                        specifies opacity
                                                                                        monitoring requirements.
63.9(g)(3)........................  Notification that           Yes..................
                                     criterion to continue use
                                     of alternative to
                                     relative accuracy testing
                                     has been exceeded.
63.9(h)...........................  Notification of compliance  Yes..................
                                     status.
63.9(i)...........................  Adjustment to time periods  Yes..................
                                     or postmark deadlines for
                                     submittal and review of
                                     required communications.
63.9(j)...........................  Change in information       Yes..................
                                     already provided.
63.10(a)..........................  Recordkeeping               Yes..................  See Sec.   63.866.
                                     requirements--applicabili
                                     ty and general
                                     information.
63.10(b)(1).......................  Records retention.........  Yes..................
63.10(b)(2)(i)....................  Recordkeeping of            No...................  See Sec.   63.866(c)(8)
                                     occurrence and duration                            for recordkeeping of the
                                     of startups and shutdowns.                         date, time, and duration
                                                                                        of each startup and/or
                                                                                        shutdown period.
63.10(b)(2)(ii)...................  Recordkeeping of failures   No...................  See Sec.   63.866(d) for
                                     to meet a standard.                                recordkeeping of (1)
                                                                                        date, time and duration;
                                                                                        (2) listing of affected
                                                                                        source or equipment, and
                                                                                        an estimate of the
                                                                                        quantity of each
                                                                                        regulated pollutant
                                                                                        emitted over the
                                                                                        standard; and (3)
                                                                                        actions to minimize
                                                                                        emissions and correct
                                                                                        the failure.
63.10(b)(2)(iii)..................  Maintenance records.......  Yes..................
63.10(b)(2)(iv)-(v)...............  Actions taken to minimize   No...................
                                     emissions during SSM.
63.10(b)(2)(vi)...................  Recordkeeping for CMS       Yes..................
                                     malfunctions.
63.10(b)(2)(vii)-(xiv)............  Other CMS requirements....  Yes..................
63.10(b)(3).......................  Records retention for       Yes..................  Applicability
                                     sources not subject to                             requirements are given
                                     relevant standard.                                 in Sec.   63.860.
63.10(c)(1)-(14)..................  Additional recordkeeping    Yes..................
                                     requirements for sources
                                     with CMS..
63.10(c)(15)......................  Use of SSM plan...........  No...................
63.10(d)(1).......................  General reporting           Yes..................
                                     requirements.
63.10(d)(2).......................  Reporting results of        Yes..................
                                     performance tests.

[[Page 97095]]

 
63.10(d)(3).......................  Reporting results of        Yes..................  Subpart MM does not
                                     opacity or VE                                      include any opacity or
                                     observations.                                      VE standards; however,
                                                                                        Sec.   63.864 specifies
                                                                                        opacity monitoring
                                                                                        requirements.
63.10(d)(4).......................  Progress reports..........  Yes..................
63.10(d)(5)(i)....................  Periodic startup,           No...................  See Sec.   63.867(c)(3)
                                     shutdown, and malfunction                          for malfunction
                                     reports.                                           reporting requirements.
63.10(d)(5)(ii)...................  Immediate startup,          No...................  See Sec.   63.867(c)(3)
                                     shutdown, and malfunction                          for malfunction
                                     reports.                                           reporting requirements.
63.10(e)..........................  Additional reporting        Yes..................
                                     requirements for sources
                                     with CMS.
63.10(f)..........................  Waiver of recordkeeping     Yes..................
                                     and reporting
                                     requirements.
63.11.............................  Control device              No...................  The use of flares to meet
                                     requirements for flares.                           the standards in subpart
                                                                                        MM is not anticipated.
63.12.............................  State authority and         Yes..................
                                     delegations.
63.13.............................  Addresses of State air      Yes..................
                                     pollution control
                                     agencies and EPA Regional
                                     Offices.
63.14.............................  Incorporations by           Yes..................
                                     reference.
63.15.............................  Availability of             Yes..................
                                     information and
                                     confidentiality.
63.16.............................  Requirements for            Yes..................
                                     Performance Track member
                                     facilities.
----------------------------------------------------------------------------------------------------------------

[FR Doc. 2016-30758 Filed 12-29-16; 8:45 am]
 BILLING CODE 6560-50-P