```

[Federal Register Volume 80, Number 199 (Thursday, October 15, 2015)]
[Rules and Regulations]
[Pages 62389-62427]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-25137]

[[Page 62389]]

Vol. 80

Thursday,

No. 199

October 15, 2015

Part IV

Environmental Protection Agency

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

40 CFR Part 63

 National Emission Standards for Hazardous Air Pollutants for Primary 
Aluminum Reduction Plants; Final Rule

Federal Register / Vol. 80 , No. 199 / Thursday, October 15, 2015 / 
Rules and Regulations

[[Page 62390]]

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

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 63

[EPA-HQ-OAR-2011-0797; FRL-9934-16-OAR]
RIN 2060-AQ92

National Emission Standards for Hazardous Air Pollutants for 
Primary Aluminum Reduction Plants

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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

SUMMARY: This action finalizes the residual risk and technology review 
(RTR) conducted for the Primary Aluminum Production source category 
regulated under national emission standards for hazardous air 
pollutants (NESHAP). In addition, we are taking final action regarding 
new and revised emission standards for various hazardous air pollutants 
(HAP) emitted by this source category based on the RTR, newly obtained 
emissions test data, and comments we received in response to the 2011 
proposal and 2014 supplemental proposal.
    These final amendments include technology-based standards and work 
practice standards reflecting performance of maximum achievable control 
technology (MACT), and related monitoring, reporting, and testing 
requirements, for several previously unregulated HAP from various 
emissions sources. Furthermore, based on our risk review, we are 
finalizing new and revised emission standards for certain HAP emissions 
from potlines using the Soderberg technology to address risk. We are 
also adding a requirement for electronic reporting of compliance data, 
eliminating the exemptions for periods of startup, shutdown, and 
malfunctions (SSM), and not adopting the affirmative defense provisions 
proposed in 2011, consistent with a recent court decision vacating the 
affirmative defense provisions. This action will provide improved 
environmental protection regarding potential emissions of HAP emissions 
from primary aluminum reduction facilities.

DATES: This final action is effective on October 15, 2015. The 
incorporation by reference of certain publications listed in the rule 
is approved by the Director of the Federal Register as of October 15, 
2015.

ADDRESSES: The Environmental Protection Agency (EPA) has established a 
docket for this action under Docket ID No. EPA-HQ-OAR-2011-0797. All 
documents in the docket are listed on the www.regulations.gov Web site. 
Although listed in the index, some information is not publicly 
available, e.g., confidential business information (CBI) or other 
information whose disclosure is restricted by statute. Certain other 
material, such as copyrighted material, is not placed on the Internet 
and will be publicly available only in hard copy form. Publicly 
available docket materials are available either electronically through 
http://www.regulations.gov, or in hard copy at the EPA Docket Center, 
EPA WJC West Building, Room Number 3334, 1301 Constitution Ave. NW., 
Washington, DC. The Public Reading Room hours of operation are 8:30 
a.m. to 4:30 p.m. Eastern Standard Time (EST), Monday through Friday. 
The telephone number for the Public Reading Room is (202) 566-1744, and 
the telephone number for the EPA Docket Center is (202) 566-1742.

FOR FURTHER INFORMATION CONTACT: For questions about this final action, 
contact Mr. David Putney, Sector Policies and Programs Division (D243-
02), Office of Air Quality Planning and Standards, U.S. Environmental 
Protection Agency, Research Triangle Park, North Carolina, 27711; 
telephone number: (919) 541-2016; fax number: (919) 541-3207; and email 
address: putney.david@epa.gov. For specific information regarding the 
risk modeling methodology, contact Mr. Jim Hirtz, Health and 
Environmental Impacts Division (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 Mr. Patrick Yellin, Office of Enforcement and 
Compliance Assurance, U.S. Environmental Protection Agency, EPA WJC 
South Building, 1200 Pennsylvania Ave. NW., Washington, DC 20460; 
telephone number: (202) 564-2970; and email address: 
yellin.patrick@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:

AERMET AERMOD Meteorological Preprocessor
AERMOD American Meteorological Society and EPA Regulatory Model
As arsenic
BLDS bag leak detection systems
BLP Buoyant Line and Point source model
CAA Clean Air Act
CBI confidential business information
CDX Central Data Exchange
CEMS continuous emission monitoring system
CFR Code of Federal Regulations
CRA Congressional Review Act
CWPB1 center-worked prebake one
CWPB2 center-worked prebake two
CWPB3 center-worked prebake three
D/F dioxins and furans
dscm dry standard cubic meter
ERT Electronic Reporting Tool
FR Federal Register
HAP hazardous air pollutant(s)
HEM3 Human Exposure Model version 3
Hg mercury
HQ hazard quotient
IBR incorporation by reference
ICR information collection request
lb pound(s)
lb/ton pound(s) per ton
lb/yr pound(s) per year
MACT maximum achievable control technology
MIR maximum individual risk
NESHAP National Emission Standards for Hazardous Air Pollutants
Ni nickel
NTTAA National Technology Transfer and Advancement Act
PCB polychlorinated biphenyls
PM particulate matter
PM2.5 p.m. with diameter of 2.5 microns and less
POM polycyclic organic matter
PRA Paperwork Reduction Act
RDL representative detection limit
REL reference exposure level
RFA Regulatory Flexibility Act
RIA Regulatory Impact Analysis
RIN Regulatory Information Number
RTR Residual Risk and Technology Review
SSM startup, shutdown, and malfunction
SWPB side-worked prebake
TEQ toxicity equivalence
TOSHI target organ-specific hazard index
TTN Technology Transfer Network
[micro]g microgram(s)
[micro]g/dscm microgram(s) per dry standard cubic meter
UMRA Unfunded Mandates Reform Act
UPL upper prediction limit
VE visible emissions
VSS2 vertical stud Soderberg two

    Background Information. On December 6, 2011, and December 8, 2014, 
the EPA proposed revisions to the Primary Aluminum Reduction Plants 
NESHAP based on our RTR and MACT review. After considering public 
comments, in this action, we are finalizing decisions and revisions for 
the rule. We summarize some of the more significant comments we timely 
received regarding the 2011 and 2014 proposed rules and provide our 
responses in this preamble. A summary of all other public comments on 
the proposals and the EPA's responses to those comments is available in 
the National Emission Standards for

[[Page 62391]]

Hazardous Air Pollutants: Primary Aluminum Reduction Plants Summary of 
Public Comments and Responses document, which is available in the 
docket for this action (Docket ID No. EPA-HQ-OAR-2011-0797). A ``track 
changes'' version of the regulatory language that incorporates the 
changes in this action is also available in the docket for this action.
    Organization of this Document. The information in this preamble is 
organized as follows:

I. General Information
    A. Does this action apply to me?
    B. Where can I get a copy of this document and other related 
information?
    C. Judicial Review and Administrative Reconsideration
II. Background
    A. What is the statutory authority for this action?
    B. What is the Primary Aluminum Production source category and 
how does the NESHAP regulate HAP emissions from the source category?
    C. What changes did we propose for the Primary Aluminum 
Production source category in our December 6, 2011, proposal and 
December 8, 2014, proposal?
III. What is included in this final rule?
    A. What are the final rule amendments based on the risk review 
for the Primary Aluminum Production source category?
    B. What are the final rule amendments based on the technology 
review for the Primary Aluminum Production source category?
    C. What are the final rule amendments pursuant to Clean Air Act 
sections 112(d)(2) and (3) for the Primary Aluminum Production 
source category?
    D. What are the final rule amendments addressing emissions 
during periods of SSM?
    E. What other changes have been made to the Primary Aluminum 
Reduction Plants NESHAP?
    F. What are the effective and compliance dates of the standards?
    G. What are the requirements for submission of performance test 
data to the EPA?
    H. What materials are being incorporated by reference?
IV. What is the rationale for our final decisions and amendments for 
the Primary Aluminum Production source category?
    A. Residual Risk Review for the Primary Aluminum Production 
Source Category
    B. CAA Sections 112(d)(2) and (3) Revisions for the Primary 
Aluminum Production Source Category
    C. Revisions to the Work Practice Standards for the Primary 
Aluminum Production Source Category
    D. What changes did we make to the control device monitoring 
requirements for the Primary Aluminum Production source category?
    E. What changes did we make to compliance dates for the Primary 
Aluminum Production source category?
V. Summary of Cost, Environmental, and Economic Impacts and 
Additional Analyses Conducted
    A. What are the affected sources?
    B. What are the air quality impacts?
    C. What are the cost impacts?
    D. What are the economic impacts?
    E. What are the benefits?
    F. What analysis of environmental justice did we conduct?
    G. What analysis of children's environmental health did we 
conduct?
VI. Statutory and Executive Order Reviews
    A. Executive Orders 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
    K. Congressional Review Act (CRA)

I. General Information

A. Does this action apply to me?

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

 Table 1--NESHAP and Industrial Source Categories Affected by This Final
                                 Action
------------------------------------------------------------------------
                                                                NAICS a
                  NESHAP and source category                      code
------------------------------------------------------------------------
Primary Aluminum Reduction Plants............................     331312
------------------------------------------------------------------------
a North American Industry Classification System.

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

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

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

C. Judicial Review and Administrative Reconsideration

    Under Clean Air Act (CAA) section 307(b)(1), judicial review of 
this final action is available only by filing a petition for review in 
the United States Court of Appeals for the District of Columbia Circuit 
by December 14, 2015. Under CAA section 307(b)(2), the requirements 
established by this final rule may not be challenged separately in any 
civil or criminal proceedings brought by the EPA to enforce the 
requirements.
    Section 307(d)(7)(B) of the CAA further provides that ``[o]nly an 
objection to a rule or procedure which was raised with reasonable 
specificity during the period for public comment (including any public 
hearing) may be raised during judicial review.'' This section also 
provides a mechanism for the EPA to reconsider the rule ``[i]f the 
person raising an objection can demonstrate to the Administrator that 
it was impracticable to raise such objection within [the period for 
public comment] or if the grounds for such objection arose after the 
period for public comment (but within the time specified for judicial 
review) and if such objection is of central relevance to the outcome of 
the rule.'' Any person seeking to make such a demonstration should 
submit a Petition for Reconsideration to the Office of the 
Administrator, U.S. EPA, Room 3000,

[[Page 62392]]

EPA WJC North Building, 1200 Pennsylvania Ave. NW., Washington, DC 
20460, with a copy to both the person(s) listed in the preceding FOR 
FURTHER INFORMATION CONTACT section, and the Associate General Counsel 
for the Air and Radiation Law Office, Office of General Counsel (Mail 
Code 2344A), U.S. EPA, 1200 Pennsylvania Ave. NW., Washington, DC 
20460.

II. Background

A. What is the statutory authority for this action?

    Section 112 of the CAA establishes a two-stage regulatory process 
to address emissions of HAP from stationary sources. In the first 
stage, we must identify categories of sources emitting one or more of 
the HAP listed in CAA section 112(b) and then promulgate technology-
based NESHAP for those sources. ``Major sources'' are those that emit, 
or have the potential to emit, any single HAP at a rate of 10 tons per 
year (tpy) or more, or 25 tpy or more of any combination of HAP. For 
major sources, these standards are commonly referred to as MACT 
standards and must reflect the maximum degree of emission reductions of 
HAP achievable (after considering cost, energy requirements, and non-
air quality health and environmental impacts). In developing MACT 
standards, CAA section 112(d)(2) directs the EPA to consider the 
application of measures, processes, methods, systems, or techniques, 
including, but not limited to, those that reduce the volume of or 
eliminate HAP emissions through process changes, substitution of 
materials, or other modifications; enclose systems or processes to 
eliminate emissions; collect, capture, or treat HAP when released from 
a process, stack, storage, or fugitive emissions point; are design, 
equipment, work practice, or operational standards; or any combination 
of the above.
    For these MACT standards, the statute specifies certain minimum 
stringency requirements, which are referred to as MACT floor 
requirements and which may not be based on cost considerations. See CAA 
section 112(d)(3). For new sources, the MACT floor cannot be less 
stringent than the emission control achieved in practice by the best-
controlled similar source. The MACT standards for existing sources can 
be less stringent than floors for new sources, but they cannot be less 
stringent than the average emission limitation achieved by the best-
performing 12 percent of existing sources in the category or 
subcategory (or the best-performing five sources for categories or 
subcategories with fewer than 30 sources). In developing MACT 
standards, we must also consider control options that are more 
stringent than the floor under CAA section 112(d)(2). We may establish 
standards more stringent than the floor, based on the consideration of 
the cost of achieving the emissions reductions, any non-air quality 
health and environmental impacts, and energy requirements.
    In the second stage of the regulatory process, the CAA requires the 
EPA to undertake two different analyses, which we refer to as the 
technology review and the residual risk review. Under the technology 
review, we must review the technology-based standards and revise them 
``as necessary (taking into account developments in practices, 
processes, and control technologies)'' no less frequently than every 8 
years, pursuant to CAA section 112(d)(6). Under the residual risk 
review, we must evaluate the risk to public health remaining after 
application of the technology-based standards and revise the standards, 
if necessary, to provide an ample margin of safety to protect public 
health or to prevent, taking into consideration costs, energy, safety, 
and other relevant factors, an adverse environmental effect. The 
residual risk review is required within 8 years after promulgation of 
the technology-based standards, pursuant to CAA section 112(f). In 
conducting the residual risk review, if the EPA determines that the 
current standards provide an ample margin of safety to protect public 
health, it is not necessary to revise the MACT standards pursuant to 
CAA section 112(f).\1\ For more information on the statutory authority 
for this rule, see 76 FR 76259 and 79 FR 72914.
---------------------------------------------------------------------------

    \1\ The U.S. Court of Appeals has affirmed this approach of 
implementing CAA section 112(f)(2)(A). See 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.'').
---------------------------------------------------------------------------

    Today's amendments involve rule changes pursuant to these 
authorities. Specifically, pursuant to CAA sections 112(d)(2) and (3), 
and 112(h), the EPA is amending the NESHAP to add standards for HAP not 
previously addressed. In addition, pursuant to CAA section 112(f), the 
EPA is amending certain MACT standards already promulgated to address 
risk. The EPA also conducted a technology review and determined that no 
further changes to the rule are necessary (within the meaning of CAA 
section 112(d)(6)) to reflect developments in practices, processes, and 
control technologies other than the work practices for anode bake 
furnaces and paste plants during startup periods, and work practices 
for potlines during normal operations (to help minimize POM, TF, and PM 
emissions), described in the 2011 and 2014 proposals.

B. What is the Primary Aluminum Production source category and how does 
the NESHAP regulate HAP emissions from the source category?

    The EPA promulgated the Primary Aluminum Reduction Plants NESHAP, 
which apply to the Primary Aluminum Production source category, on 
October 7, 1997 (62 FR 52407). The rule was amended on November 2, 2005 
(70 FR 66280). The associated standards are codified at 40 CFR part 63, 
subpart LL.
    The Primary Aluminum Production source category consists of 
facilities that produce aluminum from refined bauxite ore (also known 
as alumina), using an electrolytic reduction process in a series of 
cells called a ``potline.'' The two main potline types are prebake (a 
newer, higher-efficiency, lower-emitting technology) and Soderberg (an 
older, lower-efficiency, higher-emitting technology). The raw materials 
include alumina, petroleum coke, pitch, and fluoride salts. According 
to information available on the Web site of The Aluminum Association, 
Inc. (http://www.aluminum.org), approximately 40 percent of the 
aluminum produced in the U.S. comes from primary aluminum facilities. 
The other 60 percent either comes from Secondary Aluminum Production 
facilities or is imported.
    Primary aluminum reduction facilities emit HAP from four basic 
processes: Pitch storage tanks, paste production plants, anode bake 
furnaces, and potlines. Operators form anode paste in the paste 
production plant from a mixture of petroleum coke and pitch. In a 
prebake facility, this anode paste is then formed into anodes and baked 
in an anode bake furnace. Operators subsequently place these 
``prebaked'' anodes into a prebake potline where they are consumed via 
the electrolytic reduction process. Soderberg facilities do not have 
anode bake furnaces. Instead, the anode paste is fed directly into the 
Soderberg potlines and baked in place to form anodes, which again are 
consumed via the electrolytic reduction process.
    There are currently 11 facilities located in the United States that 
are subject to the requirements of this NESHAP: 10 primary aluminum 
reduction plants and one carbon-only prebake anode production facility. 
These 10 primary aluminum reduction

[[Page 62393]]

plants have approximately 35 potlines that produce aluminum. Each of 
the 10 primary aluminum reduction plants has a paste production plant 
and at least one anode bake furnace (for a total of about 22 existing 
anode bake furnaces). However, not all existing paste production plants 
and anode bake furnaces are currently operating, as some facilities 
obtain their prebaked anodes from the carbon-only prebake anode 
production facility. All currently operating primary aluminum 
facilities use prebake potlines.
    At the time of the 2011 proposal, there were two facilities in the 
U.S. that used Soderberg potlines. One of those facilities (Massena 
East) was operating at that time, and the other (Columbia Falls) was 
idle. However, in 2014, before publication of the supplemental 
proposal, the Massena East facility was permanently shut down. 
Therefore, at the time we published the supplemental proposal, there 
was only one Soderberg facility (Columbia Falls) in the U.S., which was 
idle. After publication of the 2014 supplemental proposal, we learned 
that the one remaining idle Soderberg facility located in Columbia 
Falls was permanently shut down. We also learned that one prebake 
facility (run by Ormet Primary Aluminum Corporation) was shut down. 
Therefore, currently there are 10 existing facilities with potlines 
(all prebake facilities) in the source category plus the one facility 
without potlines that only produces anodes.
    The major HAP emitted by these facilities are carbonyl sulfide 
(COS), hydrogen fluoride (HF), particulate HAP metals and polycyclic 
organic matter (POM), specifically polycyclic aromatic hydrocarbons 
(PAH).
    The current Primary Aluminum Reduction Plants NESHAP (as they 
existed before today's final action) included MACT standards 
(promulgated in 1997 and 2005) for emissions of total fluorides (TF) 
(as a surrogate for HF) from anode bake furnaces and potlines and for 
emissions of POM from paste production plants, anode bake furnaces, 
Soderberg potlines, and new pitch storage tanks.

C. What changes did we propose for the Primary Aluminum Production 
source category in our December 6, 2011, proposal and our December 8, 
2014, proposal?

    On December 6, 2011, and December 8, 2014, the EPA published 
proposed rules in the Federal Register for the Primary Aluminum 
Reduction Plants NESHAP, 40 CFR part 63, subpart LL, that took into 
consideration the RTR analyses and other reviews of the rule. In the 
proposed rules, we proposed several minor clarifications and 
corrections, and the items summarized in Table 2, below.

  Table 2--Summary of Changes Proposed Pursuant to Analyses Associated
                            With This Action
------------------------------------------------------------------------
                                                         As a result of
            Action                     Proposal          which analysis
------------------------------------------------------------------------
2011 proposal (76 FR 76259)...  COS emission limits     CAA section
                                 for new and existing    112(d)(2) and
                                 potlines.               (3).
                                POM emission limits
                                 for new and existing
                                 prebake potlines and
                                 existing pitch
                                 storage tanks.
                                Work practices for      CAA section
                                 anode bake furnaces     112(d)(6)
                                 during startup          Technology
                                 periods.                review.
                                Work practices for      CAA section
                                 potlines during         112(h).
                                 startup periods.
                                Revised POM emission    CAA section
                                 limits for Soderberg    112(f) Risk
                                 potlines.               Review.
2014 proposal (79 FR 72914)...  Revised POM emission    CAA section
                                 limits for new and      112(d)(2) and
                                 existing prebake        (3).
                                 potlines.
                                Emission limits for
                                 particulate matter
                                 (PM) for new and
                                 existing potlines,
                                 anode bake furnaces
                                 and paste production
                                 plants.
                                Revised work practice
                                 standards for
                                 potlines.
                                Reduced testing         CAA section
                                 frequencies for         112(d)(2) and
                                 potlines.               (3).
                                Work practices for      CAA section
                                 paste production        112(d)(6)
                                 plants during startup   Technology
                                 periods.                Review.
                                Nickel (Ni), arsenic    CAA section
                                 (As) and revised POM    112(f) Risk
                                 emission limits for     Review.
                                 Soderberg potlines.
------------------------------------------------------------------------

III. What is included in this final rule?

    This action finalizes the EPA's determinations pursuant to the RTR 
provisions of CAA section 112 for the Primary Aluminum Production 
source category, finalizes our reviews of other aspects of the rule, 
and amends the Primary Aluminum Reduction Plants NESHAP based on those 
determinations and reviews. The changes being finalized in this action 
include the following: The promulgation of MACT floor-based limits for 
previously unregulated HAP (e.g., COS and PM); emissions limits for 
POM, As, and Ni from Soderberg potlines to address risk; the addition 
of work practice standards for paste production plants, potlines and 
anode bake furnaces; and the removal of SSM exemptions. This final 
action includes several changes to the proposed requirements in the 
December 2011 and December 2014 proposals based on consideration of 
comments and information received during the public comment periods as 
described in section IV of this preamble.

A. What are the final rule amendments based on the risk review for the 
Primary Aluminum Production source category?

    This section provides a summary of the final amendments to the 
Primary Aluminum Reduction Plants NESHAP being promulgated in this 
action pursuant to CAA section 112(f).
    To address risk, we are promulgating emission limits for POM, As, 
and Ni from existing vertical stud Soderberg two (VSS2) potlines at the 
following levels: 1.9 pounds (lb) POM/ton of aluminum produced, 0.006 
lb As/ton of aluminum produced, and 0.07 lb Ni/ton of aluminum 
produced.
    To address risk, we are promulgating As and Ni emission limits for 
new Soderberg potlines at the following levels: 0.006 lb As/ton of 
aluminum produced and 0.07 lb Ni/ton of aluminum produced. New or 
reconstructed Soderberg potlines would also be subject to the POM limit 
of 0.77 lb per ton of aluminum produced that we are promulgating for 
all new potlines. These emission limits for POM, Ni, and As for new and 
existing Soderberg plants being promulgated in this rule are the same 
as the limits proposed in the 2014 supplemental proposal. Additional 
information regarding the limits addressing risk is available in the 
Development of Emissions Standards to Address Risks for the Primary 
Aluminum Production Source Category Pursuant to Section 112(f) of the 
Clean Air Act, which is

[[Page 62394]]

available in the docket for this rulemaking (Docket ID No. EPA-HQ-OAR-
2011-0797). As noted earlier, the last remaining Soderberg primary 
aluminum facility in the U.S. announced the permanent closure of that 
facility after publication of the supplemental proposal in 2014. 
Notwithstanding our well-supported expectation that this facility will 
not reopen and that no new Soderberg facilities will be constructed due 
to the less efficient and higher emitting nature of the Soderberg 
technology, we are finalizing, as proposed, the standards for POM, As, 
and Ni associated with Soderberg facilities in the final rule to 
address the risk from existing potlines at the Columbia Falls facility 
that have not yet been demolished and to ensure that risks would be 
acceptable and to provide an ample margin of safety in the very 
unlikely event that a new Soderberg facility is ever built.

B. What are the final rule amendments based on the technology review 
for the Primary Aluminum Production source category?

    Based on our analyses of the data and information collected and our 
general understanding of the industry and other available information 
on potential controls for this industry, we have determined that there 
are no developments in practices, processes, and control technologies 
that warrant revisions to the MACT standards for this source category, 
other than the work practices for anode bake furnaces during startup 
periods (described in the December 2011 proposal), the work practices 
for paste plants during startup (described in the 2014 proposal) and 
work practices for potlines (to minimize emissions of PM, TF and POM) 
during normal operations (described in the 2014 supplemental proposal). 
We are promulgating these work practices as proposed for anode bake 
furnaces and paste plants during startup periods, and for potlines 
during normal operations, under section 112(d)(6) of the CAA. These 
standards apply to both new and existing sources using either of the 
production technologies.
    In summary, we are not revising the MACT standards under CAA 
section 112(d)(6) other than the startup work practices for anode bake 
furnaces and paste plants described in the 2011 and 2014 proposals, and 
the work practices for potlines during normal operations described in 
the 2014 supplemental proposal. Additional information is available in 
the Final Technology Review for the Primary Aluminum Production Source 
Category document, which can be found in the docket for this rulemaking 
(Docket ID No. EPA-HQ-OAR-2011-0797).

C. What are the final rule amendments pursuant to Clean Air Act 
sections 112(d)(2) and (3) for the Primary Aluminum Production source 
category?

    We are promulgating MACT emission limits for COS, PM (as a 
surrogate for HAP metals other than mercury (Hg)), Hg, and 
polychlorinated biphenyls (PCB),\2\ all of which were previously 
unregulated HAP, pursuant to CAA sections 112(d)(2) and (3). In 
addition, we are promulgating MACT limits for emissions of POM from new 
and existing prebake potlines and existing pitch storage tanks, which 
were previously unregulated sources of POM. A summary of the 
promulgated MACT standards is provided in Table 3, below, and 
additional information is available in the Final MACT Floor Analysis 
for the Primary Aluminum Production Source Category document, which is 
available in the docket for this action (Docket ID No. EPA-HQ-OAR-2011-
0797). For more information on the MACT standards that the EPA 
promulgated and how they are different from those the EPA proposed, see 
section VI.B of this preamble.
---------------------------------------------------------------------------

    \2\ From Soderberg potlines only.

             Table 3--Summary of Promulgated MACT Standards
------------------------------------------------------------------------
                                                      Promulgated MACT
             HAP                     Source               standard
------------------------------------------------------------------------
COS.........................  New potlines........  3.1 lb/ton aluminum
                                                     produced.
                              Existing potlines...  3.9 lb/ton aluminum
                                                     produced.
POM.........................  New potlines........  0.77 lb/ton aluminum
                                                     produced.
                              Existing potlines:
                                 CWPB1............  1.1 lb/ton aluminum
                                                     produced.
                                 CWPB2............  12 lb/ton aluminum
                                                     produced.
                                 CWPB3............  2.7 lb/ton aluminum
                                                     produced.
                                 SWPB.............  17 lb/ton aluminum
                                                     produced.
                              Existing pitch        Minimum 95-percent
                               storage tanks.        reduction of inlet
                                                     POM emissions.
PM..........................  New potlines........  4.9 lb/ton aluminum
                                                     produced.
                              Existing potlines:
                                 CWPB1............  7.4 lb/ton aluminum
                                                     produced.
                                 CWPB2............  11 lb/ton aluminum
                                                     produced.
                                 CWPB3............  20 lb/ton aluminum
                                                     produced.
                                 SWPB.............  4.9 lb/ton aluminum
                                                     produced.
                                 VSS2.............  26 lb/ton aluminum
                                                     produced.
                              New anode bake        0.07 lb/ton of green
                               furnace.              anode produced.
                              Existing anode bake   0.20 lb/ton of green
                               furnace.              anode produced.
                              New paste production  0.0056 lb/ton of
                               plant.                paste produced.
                              Existing paste        0.082 lb/ton of
                               production plant.     paste produced.
PCB.........................  New and existing      2.0 micrograms
                               Soderberg potlines.   ([micro]g) toxicity
                                                     equivalence (TEQ)
                                                     per ton of aluminum
                                                     produced.
Hg..........................  New and existing      1.7 [mu]g per dry
                               anode bake furnaces.  standard cubic
                                                     meter (dscm).
------------------------------------------------------------------------
CWPB1 = Center-worked prebake one.
CWPB2 = Center-worked prebake two.
CWPB3 = Center-worked prebake three.
SWPB = Side-worked prebake.
VSS2 = Vertical stud Soderberg two.

[[Page 62395]]

D. What are the final rule amendments addressing emissions during 
periods of SSM?

    We are finalizing, as proposed in the 2014 proposal, changes to the 
Primary Aluminum Reduction Plants NESHAP to eliminate the exemption in 
the present rules for emissions occurring during SSM operations. 
Consistent with Sierra Club v. EPA, 551 F. 3d 1019 (D.C. Cir. 2008), 
the EPA is establishing standards in this rule that apply at all times. 
Appendix A to subpart LL of 40 CFR part 63 (General Provisions 
applicability table) is being revised to change several references 
related to requirements that apply during periods of SSM. We are also 
eliminating or revising certain recordkeeping and reporting 
requirements related to the eliminated SSM exemption. The EPA also made 
changes to the rule to remove or modify inappropriate, unnecessary, or 
redundant language in the absence of the SSM exemption. We are also not 
adopting the affirmative defense provisions proposed in 2011, 
consistent with a recent court decision vacating the affirmative 
defense provisions in one of the EPA's CAA section 112(d) regulations. 
NRDC v. EPA, 749 F. 3d 1055 (D.C. Cir. 2014).
    In addition, we are finalizing work practices for potlines, paste 
production plants, and anode bake furnaces during startup periods that 
will ensure improved capture and control of emissions from those 
sources.

E. What other changes have been made to the Primary Aluminum Reduction 
Plants NESHAP?

    This rule also finalizes revisions to several other Primary 
Aluminum Reduction Plants NESHAP requirements as proposed, or in some 
cases with some modification, which are summarized in this section.
1. Electronic Reporting Tool
    To increase the ease and efficiency of data submittal and data 
accessibility, we are finalizing, as proposed, a requirement that 
owners and operators of sources subject to the Primary Aluminum 
Reduction Plants NESHAP submit electronic copies of certain required 
performance test reports through an electronic performance test report 
tool called the Electronic Reporting Tool (ERT). This requirement to 
submit performance test data electronically to the EPA does not require 
any additional performance testing and applies only to those 
performance tests conducted using test methods that are supported by 
the ERT. A listing of the pollutants and test methods supported by the 
ERT is available at the ERT Web site.
2. Work Practice Standards
    We are finalizing work practice standards for all potlines (i.e. 
both prebake and Soderberg) and for anode bake furnaces that will 
ensure improved capture and control of TF, POM, and PM emissions from 
those sources. These work practice standards also address Hg emissions 
from all potlines, PCB emissions from prebake potlines and anode bake 
furnaces, and dioxins and furan (D/F) emissions from Soderberg potlines 
(see section IV.C of this preamble for additional discussion of these 
work practice standards).
3. Control Device and Emissions Monitoring
    We are finalizing new twice-daily visible emissions (VE) monitoring 
requirements as an alternative to bag leak detection systems (BLDS) or 
PM continuous emissions monitoring systems (CEMS) for control devices 
installed on existing sources (see section IV.D of this preamble for 
additional discussion of these monitoring changes).
    We are finalizing the inclusion of PM for the potline similarity 
option found in the current subpart LL at 40 CFR 63.848(d). This 
section allows an owner or operator to use the monitoring of secondary 
TF and/or POM emissions from one potline to represent the performance 
of other ``similar'' potlines. Potlines are similar ``if the owner or 
operator demonstrates that their structure, operability, type of 
emissions, volume of emissions and concentration of emissions are 
substantially equivalent.'' Based on consideration of comments and 
information received in responses to the 2014 proposal, the EPA is 
amending the existing rule to allow potline owners or operators this 
same option for PM. That is, potline owners and operators now will have 
the option to establish ``similarity of potlines'' with respect to PM 
emissions. ``Similarity'' would be established based on the criteria 
already applicable with respect to TF and POM. See subpart LL at 40 CFR 
63.848(d). As with TF and POM, an owner or operator would have to make 
this demonstration to the applicable regulatory authority and obtain 
approval from that authority.
4. Emission Averaging
    We are modifying 40 CFR 63.846 to allow emission averaging in the 
case of PM from potlines and anode bake furnaces. That section 
currently allows emission averaging in the cases of POM and TF from 
these process units with certain prohibitions (e.g., averaging between 
different pollutants or process units is not allowed). We are only 
adding PM to these existing provisions, and not reopening the core 
concept of allowing emission averaging.
5. Alternative Emissions Limits for Co-Controlled New and Existing 
Anode Bake Furnaces
    We are also finalizing the alternative emissions limits for co-
controlled new and existing anode bake furances as proposed in the 2014 
supplemental proposal (79 FR 72949).
6. Minor Technical and Editorial Revisions
    We are also finalizing other minor technical and editorial changes 
to the NESHAP in response to comments received during the public 
comment period for the proposal and supplemental proposal, as described 
in this preamble.

F. What are the effective and compliance dates of the standards?

    The revisions to the MACT standards being promulgated in this 
action are effective on October 15, 2015.
    The compliance dates for existing sources are:
    October 15, 2015 for the malfunction provisions and the electronic 
reporting provisions;
    October 17, 2016 for potline work practice standards and COS 
emission limits, for Soderberg potline PM and PCB emission limits, and 
for anode bake furnace and paste production plant work practices and PM 
emission limits; and
    October 16, 2017 for prebake potline POM and PM emission limits; 
for Soderberg potline revised POM emission limits and emission limits 
for Ni and As; for anode bake furnace Hg emission limits; and for pitch 
storage tank POM equipment standards.
    For more information on how we selected compliance dates for 
existing sources, refer to section IV.E of this preamble and the Final 
Rationale for Selection of Compliance Dates for the Primary Aluminum 
Production Source Category document, which can be found in the docket 
for this rulemaking (Docket ID No. EPA-HQ-OAR-2011-0797).
    New sources must typically comply with all of the standards 
immediately upon the effective date of the standard, or upon startup, 
whichever is later. CAA section 112(i)(1).\3\ CAA section 112(a)(4)

[[Page 62396]]

indicates that a new source is one which commenced construction (or 
reconstruction) after the Administrator first proposes regulations 
under CAA section 112 for the source category. We have interpreted this 
date to be the date of the December 2014 proposal given the 
substantially new record set forth in that proposal. Consequently, for 
the purposes of compliance with the emission standards for PM, a new 
affected potline, anode bake furnace, or paste production plant is one 
for which construction or reconstruction commenced after December 8, 
2014, the date on which the EPA first proposed the amendments finalized 
here. For the purposes of compliance with the emission standards for 
POM and COS, a new affected potline is one for which construction or 
reconstruction commenced after December 8, 2014. For the purposes of 
compliance with the emission standards for Hg or PCB, a new affected 
anode bake furnace or Soderberg potline is one for which construction 
or reconstruction commenced after December 8, 2014, although the 
compliance dates for these standards are October 16, 2017 for anode 
bake furnaces and October 17, 2016 for Soderberg potlines, since these 
standards differ from the proposal (see CAA section 112(i)(2)).
---------------------------------------------------------------------------

    \3\ If a new source standard is more stringent than the standard 
proposed, a new source may have three years to comply, provided it 
complies with the proposed standard during that 3-year period. CAA 
section 112(i)(2).
---------------------------------------------------------------------------

G. What are the requirements for submission of performance test data to 
the EPA?

    The EPA is requiring owners and operators of sources subject to the 
Primary Aluminum Reduction Plants NESHAP facilities to submit 
electronic copies of certain required performance test reports [and any 
other reports, e.g. performance evaluation reports] through the EPA's 
Central Data Exchange (CDX) using the Compliance and Emissions Data 
Reporting Interface (CEDRI). As stated in the 2011 proposal preamble, 
the EPA believes that the electronic submittal of the reports addressed 
in this 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. 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.
    As mentioned in the preamble of the 2011 proposal, 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 the records, data and reports 
addressed in this rulemaking readily available, the EPA, the regulated 
community and the public will benefit when the EPA conducts its CAA-
required technology and risk-based reviews. As a result of having 
reports readily accessible, our ability to carry out comprehensive 
reviews will be increased and achieved within a shorter period of time.
    We anticipate fewer or less substantial information collection 
requests (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. 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.
    Air agencies could benefit from more streamlined and automated 
review of the electronically submitted data. 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. The ability to access and 
review air emission report information electronically will assist air 
agencies 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 air agencies and the general public.
    For a more thorough discussion of electronic reporting required by 
this rule, see the discussion in the preamble of the 2011 proposal (see 
76 FR 76280). In summary, in addition to supporting regulation 
development, control strategy development, and other air pollution 
control activities, having an electronic database populated with 
performance test data will save industry, air agencies, and the EPA 
significant time, money, and effort while improving the quality of 
emission inventories, air quality regulations, and enhancing the 
public's access to this important information.

H. What materials are being incorporated by reference?

    In this final rule, the EPA is including regulatory text that 
includes incorporation by reference (IBR). In accordance with 
requirements of 1 CFR 51.5, the EPA is incorporating by reference the 
following documents described in the amendments to 40 CFR 63.14:
     ASTM D4239-14e1, ``Standard Test Method for Sulfur in the 
Analysis Sample of Coal and Coke Using High-Temperature Tube Furnace 
Combustion,'' approved March 1, 2014;
     ASTM D6376-10, ``Standard Test Method for Determination of 
Trace Metals in Petroleum Coke by Wavelength Dispersive X-Ray 
Fluorescence Spectroscopy,'' approved July 1, 2010; and
     Method 428, ``Determination Of Polychlorinated Dibenzo-P-
Dioxin (PCDD), Polychlorinated Dibenzofuran (PCDF), and Polychlorinated 
Biphenyle Emissions from Stationary Sources,'' amended September 12, 
1990.
    The following material will be referenced in 40 CFR 63.14 and as 
noted below. This material has already received IBR approval for 
subpart LL of 40 CFR part 63. We are moving it from an IBR section 
established earlier within subpart LL to the centralized IBR section in 
Sec.  63.14.
     Industrial Ventilation: A Manual of Recommended Practice, 
22nd Edition, 1995, Chapter 3, ``Local Exhaust Hoods'' and Chapter 5, 
``Exhaust System Design Procedure.'' IBR approved for Sec. Sec.  
63.843(b) and 63.844(b).
     ASTM D2986-95A, ``Standard Practice for Evaluation of Air 
Assay Media by the Monodisperse DOP (Dioctyl Phthalate) Smoke Test,'' 
approved September 10, 1995, IBR approved for section 7.1.1 of Method 
315 in appendix A to 40 CFR part 63.
    The EPA has made, and will continue to make, these documents 
generally available electronically through www.regulations.gov and/or 
in hard copy at the appropriate EPA office (see the ADDRESSES section 
of this preamble for more information).

IV. What is the rationale for our final decisions and amendments for 
the Primary Aluminum Production source category?

    This section provides a description of what we proposed and what we 
are finalizing for several issues, the EPA's rationale for the final 
decisions and

[[Page 62397]]

amendments, and a summary of key comments and responses. For all 
comments not discussed in this preamble, comment summaries and the 
EPA's responses can be found in the National Emission Standards for 
Hazardous Air Pollutants: Primary Aluminum Reduction Plants Summary of 
Public Comments and Responses document, which is available in the 
docket for this action (Docket ID No. EPA-HQ-OAR-2011-0797).

A. Residual Risk Review for the Primary Aluminum Production Source 
Category

1. What did we propose pursuant to CAA section 112(f) for the Primary 
Aluminum Production source category?
    Pursuant to CAA section 112(f), we conducted a residual risk review 
and presented the results of this review, along with our proposed 
decisions regarding risk acceptability and ample margin of safety, in 
the December 2014 supplemental proposal for the Primary Aluminum 
Reduction Plants NESHAP. The EPA views the residual risk review 
associated with the 2011 proposal as superseded by the residual risk 
review associated with the 2014 supplemental proposal, and so is 
referring only to that later risk assessment. The results of the risk 
assessment for the 2014 supplemental proposal are summarized in the 
preamble for that proposal and presented in more detail in the residual 
risk document, Residual Risk Assessment for the Primary Aluminum 
Production Source Category in Support of the 2014 Supplemental 
Proposal, which is available in the docket for this rulemaking. Table 4 
below provides the estimated inhalation health risks from the 
supplemental proposal.

    Table 4--Primary Aluminum Production Source Category Inhalation Risk Assessment Results From Supplemental
                                                    Proposal
----------------------------------------------------------------------------------------------------------------
                                                        Estimated
                                                          annual
  Maximum  individual  cancer    Estimated population     cancer     Maximum chronic non-  Refined maximum acute
   risk (-in-1 million) \a\       at increased risk     incidence     cancer  TOSHI \b\       non-cancer HQ \c\
                                   levels of cancer     (cases per
                                                          year)
----------------------------------------------------------------------------------------------------------------
                                                Actual Emissions
----------------------------------------------------------------------------------------------------------------
70............................  >=1-in-1 million:             0.06  1 Cadmium and Nickel   HQREL = 10 (Arsenic
                                 881,000.                            Compounds.             Compounds).
                                >=10-in-1 million:
                                 65,000.
                                >=100-in-1 million: 0  ...........  .....................  Residential.
----------------------------------------------------------------------------------------------------------------
                                             Allowable Emissions \d\
----------------------------------------------------------------------------------------------------------------
300...........................  >=1-in-1 million:             0.06  2 Nickel and Arsenic
                                 950,000.                            Compounds.
                                >=10-in-1 million:
                                 76,000.
                                >=100-in-1 million:
                                 200.
----------------------------------------------------------------------------------------------------------------
\a\ Estimated maximum individual excess lifetime cancer risk due to HAP emissions from the source category.
\b\ Maximum TOSHI. The target organ with the highest TOSHI for the Primary Aluminum Production source category
  for actual emissions is the kidney and respiratory system and for allowable emissions is the respiratory,
  immunological, and developmental systems.
\c\ The maximum off-site HQ acute value of 10 at a residential location for actuals is driven by emissions of As
  from the potline roof vents. See section III.A.3 of the December 8, 2014 supplemental proposal for explanation
  of acute dose-response values. Acute assessments are not performed on allowable emissions.
\d\ The development of allowable emission estimates can be found in the memorandum titled Development of the RTR
  Revised Risk Modeling Dataset for the Primary Aluminum Production Source Category (Docket item number EPA-HQ-
  OAR-2011-0797-0346).

    Based on actual emissions estimates for the Primary Aluminum 
Production source category supplemental proposal, the maximum 
individual risk (MIR) for cancer was estimated to be up to 70-in-1 
million driven by emissions of As and Ni compounds. The maximum chronic 
non-cancer target organ-specific hazard index (TOSHI) value was 
estimated to be up to 1 driven by Ni emissions. The maximum off-site 
acute hazard quotient (HQ) value was estimated to be 10 for As 
compounds and 2 for HF. The total estimated national cancer incidence 
from this source category, based on actual emission levels, was 0.06 
excess cancer cases per year, or one case in every 17 years.
    Based on MACT-allowable emissions, in the supplemental proposal, 
the MIR was estimated by the EPA to be up to 300-in-1 million, driven 
by potential emissions of As, Ni, and POM from the one idle Soderberg 
facility (Columbia Falls), which is now permanently closed. The maximum 
chronic non-cancer TOSHI value was estimated to be up to 2, driven by 
Ni. The MIR due to allowable emissions from prebake facilities was 
estimated by the EPA to be up to 70-in-1 million, driven by As and Ni.
    The EPA also assessed the risks due to multipathway exposures to 
HAP emissions from the primary aluminum reduction plants. The 
assessment included tier 1 and tier 2 screening analyses and a refined 
analysis for the one Soderberg facility which was operational at the 
time recent emissions data for this source category were collected and 
this analysis was commenced, but which subsequently announced its 
permanent shut down in March 2014.
    The multipathway screens rely on health-protective assumptions 
about consumption of local fish and locally grown or raised foods 
(adult female angler at 99th percentile consumption of fish \4\ for the 
subsistence fisherman scenario and 90th percentile for consumption of 
locally grown or raised foods \5\ for the farmer scenario) which may 
not occur for this source category. The tier 2 assessment is less 
conservative than the tier 1 analysis. However, it is important to note 
that, even with the inclusion of some site-specific information in the 
tier 2 analysis, the multipathway screening analysis is still a very 
conservative health-protective assessment, and, in all likelihood, will 
yield results that serve

[[Page 62398]]

as an upper-bound multipathway risk associated with any facility in the 
Primary Aluminum Production source category.
---------------------------------------------------------------------------

    \4\ Burger, J. 2002. Daily consumption of wild fish and game: 
Exposures of high end recreationists. International Journal of 
Environmental Health Research 12:343-354.
    \5\ U.S. EPA. Exposure Factors Handbook 2011 Edition (Final). 
U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-09/
052F, 2011.
---------------------------------------------------------------------------

    The highest cancer exceedance in the tier 2 analyses for dioxins 
was 40 times and 7 times for PAH for the subsistence fisherman scenario 
(total cancer screen value of 50 for the MIR site). Thus, these results 
indicate that the maximum cancer risks due to multipathway exposures to 
D/F and PAH emissions for the subsistence fisher scenario are less than 
50-in-1 million under these highly conservative screening 
assumptions.\6\ The multipathway analysis for chronic non-cancer 
effects did not identify any persistent and bioaccumulative hazardous 
air pollutants (PB-HAP) that exceeded an HQ value of 1. For more 
information on the risk results, please refer to the residual risk 
document, Residual Risk Assessment for the Primary Aluminum Production 
Source Category in Support of the 2014 Supplemental Proposal, which is 
available in the docket for this rulemaking.
---------------------------------------------------------------------------

    \6\ D/F emissions used in this analysis are likely to be 
overstated because the EPA imputed values for D/F congeners even 
from facilities and process units where those D/F congeners were not 
detected in the emissions tests.
---------------------------------------------------------------------------

    For the supplemental proposal, we weighed all health risk factors 
in our risk acceptability determination, and we proposed that the risks 
due to potential HAP emissions at baseline from the Soderberg 
subcategory were unacceptable due mainly to the estimated cancer risks 
of 300-in-1 million based on potential emissions from the one idle 
Soderberg facility were it to operate.
    Regarding the prebake subcategories, as explained in the 
supplemental proposal, the EPA had concerns regarding the potential 
acute risks due to As emissions (with a maximum acute HQ of 10). See 79 
FR 72947. However, given the conservative nature of the EPA's analysis 
of acute effects, and the facts that: (a) The inhalation cancer MIR was 
well below 100-in-1 million (MIR = 70-in-1 million); (b) the chronic 
non-cancer risks were low (e.g., hazard index (HI) = 1); and (c) given 
further that the multipathway assessment indicated the maximum cancer 
risk due to multipathway exposures to HAP emissions from prebake 
facilities was no higher than 50-in-1 million, we proposed that the 
risks due to emissions from the prebake subcategories are acceptable. 
See 79 FR 72947.
2. How did the risk review change for the Primary Aluminum Production 
source category?
    The EPA carefully considered public comments regarding the 
supplemental proposal (and original proposal), but did not find any 
comments that resulted in a change in analysis. Thus, the EPA did not 
change the risk assessment due to actual emissions for the source 
category and made no changes in the overall results for prebake 
facilities from the December 2014 supplemental proposal. However, the 
estimated risks due to allowable emissions for the source category 
decreased significantly due to the permanent closure of the one idle 
Soderberg facility. For the supplemental proposal, we included the one 
idle Soderberg facility in our assessment of allowable risks because, 
at that time, the facility still had a permit to operate, had not 
formally announced plans to close, and, therefore, could have reopened. 
However, that facility is now permanently closed, and the EPA is no 
longer including it in the risk assessment. Therefore, the final rule 
considers only risks from prebake facilities. Nevertheless, as 
discussed in section III.A. of this preamble, we are promulgating the 
As, Ni and POM standards proposed in the supplemental proposal to 
address risk from Soderberg facilities in the very unlikely event that 
either this idle Soderberg facility is reopened or a new Soderberg 
facility is constructed. A summary of the risk assessment results for 
the final rule is provided in Table 5 below. The documentation and 
details for the final rule risk assessment can be found in the document 
titled, Residual Risk Assessment for the Primary Aluminum Production 
Source Category in Support of the September 2015 Risk and Technology 
Review Final Rule, which is available in the docket for this action 
(Docket ID No. EPA-HQ-OAR-2011-0797).

   Table 5--Primary Aluminum Production Source Category Inhalation Risk Assessment Results for the Final Rule
                                                    [Prebake]
----------------------------------------------------------------------------------------------------------------
                                                         Estimated
                                                           annual
  Maximum  individual  cancer    Estimated population      cancer    Maximum chronic non-  Refined maximum acute
   risk (-in-1 million) \a\        at increased risk     incidence     cancer TOSHI \b\      non-cancer HQ \c\
                                   levels of cancer      (cases per
                                                           year)
----------------------------------------------------------------------------------------------------------------
                                                Actual Emissions
----------------------------------------------------------------------------------------------------------------
70............................  >=1-in-1 million:              0.06  1 Nickel Compounds..  HQREL = 10 (Arsenic
                                 881,000.                                                   Compounds)
                                >=10-in-1 million:      ...........  ....................  Residential
                                 65,000.
----------------------------------------------------------------------------------------------------------------
                                             Allowable Emissions \d\
----------------------------------------------------------------------------------------------------------------
70............................  >=1-in-1 million:              0.06  1 Nickel Compounds..
                                 950,000.
                                >=10-in-1 million:
                                 76,000.
----------------------------------------------------------------------------------------------------------------
\a\ Estimated maximum individual excess lifetime cancer risk due to HAP emissions from the source category.
\b\ Maximum TOSHI. The target organ with the highest TOSHI for the Primary Aluminum Production source category
  for actual emissions is the kidney and respiratory system and for allowable emissions is the respiratory,
  immunological, and developmental systems.
\c\ The maximum off-site HQ acute value of 10 at a residential location for actuals is driven by emissions of As
  from the potline roof vents. See section III.A.3 of the December 8, 2014, supplemental proposal for
  explanation of acute dose-response values. Acute assessments are not performed on allowable emissions.
\d\ The development of allowable emission estimates can be found in the memorandum titled, Development of the
  RTR Revised Risk Modeling Dataset for the Primary Aluminum Production Source Category (Docket item number EPA-
  HQ-OAR-2011-0797-0346).

[[Page 62399]]

    For the final rule, we again weighed all health risk factors in our 
risk acceptability determination. The EPA had concerns regarding the 
potential acute risks due to As emissions (with a maximum acute HQ of 
10). See 79 FR 72947. However, given the conservative nature of the 
EPA's analysis of acute effects, and the facts that: (a) The inhalation 
cancer MIR was well below 100-in-1 million (MIR = 70-in-1 million); (b) 
the chronic non-cancer risks were low (e.g., HI = 1); and (c) given 
further that the multipathway assessment indicated the maximum cancer 
risk due to multipathway exposures to HAP emissions from prebake 
facilities was no higher than 50-in-1 million, we have determined that 
the risks due to emissions from the source category are acceptable. See 
79 FR 72947.
    We also conducted an ample margin of safety analysis. As we 
described in the supplemental proposal, for prebake facilities we 
considered what further reductions might be obtained from technically 
feasible controls, further considering the cost of such controls and 
their cost-effectiveness. We identified no cost-effective controls 
under the ample margin of safety analysis to further reduce risks or 
environmental effects due to HAP emissions from prebake facilities. 79 
FR 72947-48. Therefore, we indicated in the supplemental proposal, and 
conclude again in this final rule, that the NESHAP for prebake 
facilities provides an ample margin of safety to protect public health 
and prevent an adverse environmental effect.
    With regard to Soderberg facilities, as mentioned in section III 
above, we proposed more stringent emission limits for Ni, As, and POM 
under CAA section 112(f) to ensure that the cancer MIR would remain 
below 100-in-1 million, the level of risk we defined as acceptable for 
purposes of this rule. We did not propose more stringent standards 
under the ample margin of safety analysis since we identified no 
feasible controls that would yield risk reductions at reasonable cost. 
Id at 72948. In this final action, we are promulgating these standards 
as proposed. Although these standards may not apply to any facilities, 
we are still promulgating the As, Ni and POM emissions limits for 
Soderberg facilities under CAA section 112(f) to address the shut down, 
but not yet demolished, existing Soderberg potlines, and the very 
unlikely scenario of construction of new Soderberg potlines.
3. What key comments did we receive on the risk review, and what are 
our responses?
    The EPA received several comments regarding the revised risk 
assessment for the Primary Aluminum Production source category. The 
following is a summary of some key comments and our responses to those 
comments. Other comments received and our responses to those comments 
can be found in the document titled, National Emission Standards for 
Hazardous Air Pollutants: Primary Aluminum Reduction Plants Summary of 
Public Comments and Responses, which is available in the docket for 
this action (Docket ID No. EPA-HQ-OAR-2011-0797).
    Comment: One commenter stated that the EPA's determination of the 
emissions reduction required to reduce health risks to an acceptable 
level violates CAA section 112(f)(2) and is arbitrary. The commenter 
believed that the EPA's acceptability determination for prebake 
facilities is flawed for the following reasons:
     The EPA's acceptability determination is unlawful and 
arbitrary because its risk assessment is incomplete and fails to follow 
the up-to-date science to assess health risk;
     The EPA's acceptability determination fails to consider or 
prevent unacceptable levels of cumulative impacts;
     Socioeconomic disparity in health risk from this source 
category makes the risk the EPA has found unacceptable, and the EPA 
must finalize a rule that is consistent with the principle of 
environmental justice (EJ);
     The EPA has failed to provide a reasoned explanation for 
why the lifetime cancer risk of 1-in-1 million or more based on 
inhalation alone from this sector is acceptable;
     After finding a level of acute risk that is 10 times the 
EPA's safety threshold, the agency has failed to justify not requiring 
the reduction of acute health risk below 1; and
     The EPA has failed to justify finding chronic non-cancer 
health risk to be acceptable.
    Response: We disagree with the commenter that the assessment is 
incomplete and fails to use up-to-date science. The dose-response 
values used in the risk assessment are based on the current peer 
reviewed Integrated Risk Information System (IRIS) values, as well as 
other similarly peer-reviewed values. Our approach, which uses 
conservative tools and assumptions, ensures that our decisions are 
appropriately health protective and environmentally protective. The 
approach for selecting appropriate health benchmark values, in general, 
places greater weight on the EPA derived health benchmarks than those 
from other agencies (see http://www.epa.gov/ttn/atw/nata1999/99pdfs/healtheffectsinfo.pdf). This approach has been endorsed by the Science 
Advisory Board (SAB).\7\ The SAB further recommended that the EPA 
scrutinize values that emerge as drivers of risk assessment results, 
and the Agency has incorporated this recommendation into the risk 
assessment process. This may result in the EPA determining that it is 
more appropriate to use a peer-reviewed dose-response value from 
another agency even if an IRIS value exists.
---------------------------------------------------------------------------

    \7\ Refer to the May 2010, SAB response to the EPA Administrator 
(EPA-SAB-10-007); http://www.regulations.gov/#!documentDetail;D=EPA-
HQ-OAR-2011-0797-0075.
---------------------------------------------------------------------------

    With regard to the comment that the EPA failed to consider 
cumulative impacts, we note that while the incorporation of additional 
background concentrations from the environment in our risk assessments 
(including those from mobile sources and other industrial and area 
sources) could be technically challenging, they are neither mandated 
nor barred from our analysis. In developing the decision framework in 
the Benzene NESHAP used for making residual risk decisions, and now 
codified in CAA section 112(f)(2)(B), the EPA rejected approaches that 
would have mandated consideration of background levels of pollution in 
assessing the acceptability of risk, concluding that comparison of 
acceptable risk should not be associated with levels in polluted urban 
air (54 FR 38044, 38061, September 14, 1989). Background levels 
(including natural background) are not barred from the EPA's ample 
margin of safety analysis, and the EPA may consider them, as 
appropriate and as available, along with other factors, such as cost 
and technical feasibility, in the second step of its CAA section 112(f) 
analysis. As discussed in the 2014 supplemental proposal, the risk 
assessment for this source category did not include background 
contributions (that may reflect emissions that are from outside the 
source category and from other than co-located sources) because the 
available data are of insufficient quality upon which to base a 
meaningful analysis.\8\
---------------------------------------------------------------------------

    \8\ Note that this question is distinct from the issue of 
consideration of emissions from co-located facilities, which 
emissions are fully reflected in the EPA's analysis. See discussion 
in section IV.A.3 of this preamble, below, and 79 FR 72929/1 
(emissions estimated for all emitting sources in a contiguous area 
under common control).

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

[[Page 62400]]

    This rule has been finalized consistent with agency EJ principles 
and analyses. To examine the potential for any EJ issues that might be 
associated with the Primary Aluminum Production source category, we 
performed a demographic analysis, which is an assessment of risks to 
individual demographic groups, of the population close to the 
facilities. In this analysis, we evaluated the distribution of HAP-
related cancer risks and non-cancer hazards from this source category 
across different social, demographic, and economic groups within the 
populations living near facilities identified as having the highest 
risks. The results of the demographic analysis are summarized in Table 
6 below and indicate that there are no significant disproportionate 
risks to any particular minority, low income, or indigenous population. 
The methodology and the results of the demographic analyses are 
included in a technical report, Analysis of Socio-Economic Factors for 
Populations Living Near Primary Aluminum Facilities, which is available 
in the docket for this rulemaking (Docket item number EPA-HQ-OAR-2011-
0797-0360).

             Table 6--Primary Aluminum Production 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         881,307               0
----------------------------------------------------------------------------------------------------------------
                                                 Race by Percent
----------------------------------------------------------------------------------------------------------------
White...........................................................              72              80               0
All Other Races.................................................              28              20               0
----------------------------------------------------------------------------------------------------------------
                                                 Race by Percent
----------------------------------------------------------------------------------------------------------------
White...........................................................            71.9            80.1               0
African American................................................              13              13               0
Native American.................................................             1.1             0.9               0
Other and Multiracial...........................................              14               6               0
----------------------------------------------------------------------------------------------------------------
                                              Ethnicity by Percent
----------------------------------------------------------------------------------------------------------------
Hispanic........................................................              17               5               0
Non-Hispanic....................................................              83              95               0
----------------------------------------------------------------------------------------------------------------
                                                Income by Percent
----------------------------------------------------------------------------------------------------------------
Below Poverty Level.............................................              14              14               0
Above Poverty Level.............................................              86              86               0
----------------------------------------------------------------------------------------------------------------
                                              Education by Percent
----------------------------------------------------------------------------------------------------------------
Over 25 and without High School Diploma.........................              15              14               0
Over 25 and with a High School Diploma..........................              85              86               0
----------------------------------------------------------------------------------------------------------------

    With regard to the comments that the EPA did not justify the 
determination that risks are acceptable, we generally draw no bright 
lines of acceptability regarding cancer or non-cancer risks from source 
category HAP emissions. This is a core feature of the Benzene NESHAP 
approach, now codified in CAA section 112(f)(2)(B). See 54 FR at 38046, 
38057; see also 79 FR 72933-34. It is always important to consider the 
specific uncertainties of the emissions and health effects information 
regarding the source category or subcategory in question when deciding 
exactly what level of cancer and non-cancer risk should be considered 
acceptable. In addition, the source category-specific or subcategory-
specific decision of what constitutes an acceptable level of risk 
should be a holistic one; that is, it should simultaneously consider 
all potential health impacts--chronic and acute, cancer and non-cancer, 
and multipathway--along with their uncertainties, when determining the 
acceptable level of source category risk. Today, such flexibility is 
even more imperative, because new information relevant to the question 
of risk acceptability is being developed all the time, and the accuracy 
and uncertainty of each piece of information must be considered in a 
weight-of-evidence approach for each decision. This relevant body of 
information is growing fast (and will likely continue to grow even 
faster), necessitating a flexible weight-of-evidence approach that 
acknowledges both complexity and uncertainty in the simplest and most 
transparent way possible. While this challenge is formidable, it is 
nonetheless the goal of the EPA's RTR decision-making, and it is the 
goal of the risk assessment to provide the information to support the 
decision-making process.
    Our acceptability decisions for the prebake subcategory presented 
in the supplemental proposal, and again in this final rule, are 
appropriate. The rationale for our acceptability decision for the 
prebake subcategory was clearly explained in the supplemental proposal 
and was based on full consideration of the health risk information and 
associated uncertainties, and we summarize it here:
    Regarding the prebake subcategories, as explained in the 
supplemental proposal, the EPA had concerns regarding the potential 
acute risks due to As emissions (with a maximum acute HQ of 10). See 79 
FR 72947. However, given the conservative nature of the EPA's analysis 
of acute effects--among them, an assumption of the unlikely confluence 
of peak emissions, worst-

[[Page 62401]]

case-meteorology, and an exposed individual present at the precise 
point this occurs (see 79 FR 72943/1), and the facts that: (a) The 
inhalation cancer MIR was well below 100-in-1 million (MIR = 70-in-1 
million); (b) the chronic non-cancer risks were low (e.g., HI = 1); and 
(c) given further that the multipathway assessment indicated the 
maximum cancer risk due to multipathway exposures to HAP emissions from 
prebake facilities was no higher than 50-in-1 million, we have 
determined that the risks due to emissions from the prebake 
subcategories are acceptable.
    Comment: A commenter stated support for the EPA's risk assessment 
conclusion that the risk due to actual emissions from the prebake 
aluminum smelting subcategory is acceptable. The commenter stated that 
the modeled ambient concentrations that were used in the risk 
assessment likely overpredict actual concentrations since the Human 
Exposure Model version 3 (HEM3) uses the American Meteorological 
Society and EPA Regulatory Model (AERMOD) for air dispersion modeling 
to determine ambient concentrations. The commenter stated that the use 
of AERMOD is inappropriate for modeling stationary line sources like 
the potroom roof monitors of the facilities and overpredicts ambient 
concentrations from roof monitor emissions by a factor of about 30 
times. The commenter recommended that the EPA use the Buoyant Line and 
Point source (BLP) dispersion model to correctly model the potline roof 
monitors.
    Response: The EPA disagrees that the BLP model needs to be used to 
correctly model potline roof monitors. An analysis performed by the EPA 
to compare the modeled estimates from AERMOD and the BLP model for a 
typical primary aluminum facility indicated that the maximum modeled 
concentrations from the BLP model were only 20 percent higher than 
those from AERMOD. Considering the uncertainties in release 
characteristics and emission rates--both inputs into the models--the 
results estimated by both HEM3 and BLP are the same within that range 
of uncertainty.\9\ The EPA concluded that this difference was not 
significant enough to warrant changing the RTR modeling methodology it 
uses for all source categories, which includes the use of AERMOD and 
meteorological data generated by the AERMOD Meteorological Preprocessor 
(AERMET). In addition, the 20 percent increase in maximum modeled 
concentrations would translate into an increase in the risk from 70-in-
1 million to 80-in-1 million. This level would still be within the 
range of acceptability and, if the EPA had determined that it was 
necessary to use the BLP, the Agency would have reaffirmed that risks 
are acceptable.
---------------------------------------------------------------------------

    \9\ September 27, 2010, Memo to the EPA from EC/R Incorporated; 
``Draft Modeling Comparison of BLP and AERMOD for Primary Aluminum'' 
available in the docket at http://www.regulations.gov/#!documentDetail;D=EPA-HQ-OAR-2011-0797-0175.
---------------------------------------------------------------------------

    Comment: One commenter stated that the EPA must strengthen the risk 
assessment and proposed risk action in order to meet its 
responsibilities under CAA section 112(f)(2) to provide the requisite 
``ample margin of safety to protect public health.'' The EPA also 
should find risk from the prebake subcategories to be unacceptable, 
instead of acceptable. The commenter stated that the combined health 
risks for these sources are substantial and stated that the EPA found 
that the allowable emissions-based cancer risk from inhalation exposure 
is 70-in-1 million, plus another 70-in-1 million from multipathway 
exposure (50-in-1 million for the ``fisher'' scenario, or fish-based 
exposure; and 20-in-1 million for the ``farmer'' scenario, or farm-
based exposure). The commenter stated that the 70-in-1 million 
inhalation risk, combined with the high acute and chronic risks the EPA 
found, is enough alone to find risk unacceptable.
    The commenter stated that in view of the EPA's scientific policy of 
summing cancer risks, it should recognize that the most-exposed 
person's combined multipathway and inhalation cancer risk is 70 + 70 or 
140-in-1 million. The commenter stated that this is well above the 
EPA's presumptive acceptability benchmark (which itself is 
insufficiently stringent, as explained in their 2012 comments, 
incorporated by reference). The commenter also stated that the EPA 
should find the current cancer risk from inhalation and multipathway 
exposure, due to a combination of As, Ni, PAH, and dioxins, is 
unacceptable. The commenter stated that if viewed together with the 
high acute and chronic non-cancer risks the EPA found, as a result of 
As and Ni in particular, the data the EPA has compiled on risk show 
that the current health risks are unacceptable.
    The commenter stated that the EPA has not assessed the additional 
multipathway risk from risk-driver pollutants, such as As and Ni. The 
commenter stated that, as discussed in their 2012 comments (to EPA's 
original proposal), this is inconsistent with the scientific evidence 
showing these are persistent bioaccumulative toxics [PBTs], and it is, 
thus, unlawful and arbitrary and capricious for the EPA not to assess 
and address the multipathway risks they create.
    Response: We disagree with the commenter's arguments for finding 
risks to be unacceptable. The thrust of the comment is that the risk 
analysis failed to combine risks from various scenarios and pathways, 
and that, added together, these risks are unacceptable. In fact, the 
analysis combines risk estimates to the extent that it is 
scientifically appropriate to do so. We consider the effect of mixtures 
of carcinogens consistent with the EPA guidelines and use a TOSHI 
approach for our chronic non-cancer assessments. We do not use a TOSHI 
approach for acute analyses, nor do we combine the results of our 
inhalation and multipathway assessments. (See the Residual Risk 
Assessment for the Primary Aluminum Production Source Category in 
Support of the September 2015 Risk and Technology Review Final Rule, 
which is available in the docket for this action (Docket ID No. EPA-HQ-
OAR-2011-0797)).
    In the multipathway screening assessment, we did not sum the risk 
results of the fisher and farmer scenarios. The modeling approach used 
for this analysis constructs two different exposure scenarios, which 
serves as a conservative estimate of potential risks to the most-
exposed receptor in each scenario. Given that it is highly unlikely 
that the most-exposed farmer is the same person as the most-exposed 
fisher, it is not reasonable to add risk results from these two 
exposure scenarios (see Appendix 5 and Section 2.5 of the Residual Risk 
Assessment for the Primary Aluminum Production Source Category in 
Support of the September 2015 Risk and Technology Review Final Rule).
    We do not find it reasonable to combine the results of our 
inhalation and multipathway assessments for this source category. The 
multipathway risk assessment for prebake facilities was a screening-
level assessment. The screening assessment used highly conservative 
assumptions designed to ensure that sources with results below the 
screening threshold values did not have the potential for multipathway 
impacts of concern. The screening scenario is a hypothetical scenario, 
and, due to the theoretical construct of the screening model, 
exceedances of the thresholds are not directly translatable into 
estimates of risk or HQs for these facilities. Rather, it represents a 
high-end estimate of what the risk or hazard may be. For example, an 
exceedance of 2 for a non-carcinogen can be interpreted to mean that we 
have high confidence that the HQ or HI would be

[[Page 62402]]

less than 2. Similarly, an exceedance of 30 for a carcinogen means that 
we have high confidence that the risk is lower than 30-in-1 million. 
Our confidence comes from the health-protective assumptions that are in 
the screens: We choose inputs from the upper end of the range of 
possible values for the influential parameters used in the screens, and 
we assume that the exposed individual exhibits ingestion behavior that 
would lead to a high total multipathway exposure. It would be 
inappropriate to sum the risk results from the chronic inhalation 
assessment and the screening multipathway assessment. In addition to 
the constraints in the screening-level multipathway assessment 
described above, it is highly unlikely that the same receptor has the 
maximum results in both assessments. In other words, it is unlikely 
that the person with the highest chronic inhalation cancer risk is also 
the same person with the highest individual multipathway cancer risk. 
We agree with the commenter that we ``should look at the whole picture 
of cancer risk,'' but we do so by assessing cancer and chronic non-
cancer inhalation risk, acute risk, multipathway risk, and combining 
risk results where it is scientifically appropriate to do so, not by 
arbitrarily and indiscriminately summing risk measures in the absence 
of a valid technical basis.
    We currently do not have screening values for some PB-HAP, but we 
disagree that the multipathway assessment is inadequate because it did 
not include ``all HAP metals emitted (such as arsenic and nickel).'' We 
developed the current PB-HAP list considering all available information 
on persistence and bioaccumulation (see http://www2.epa.gov/fera/air-toxics-risk-assessment-reference-library-volumes-1-3, specifically 
Volume 1, Appendix D). (The Air Toxics Risk Assessment Reference 
Library presents the decision process by which the PB-HAP were selected 
and provides information on the fundamental principles of risk-based 
assessment for air toxics and how to apply those principles.) In 
developing the list, we considered HAP identified as PB-HAP by other 
EPA program offices (e.g., the Great Waters Program), as well as 
information from the PBT profiler (see http://www.pbtprofiler.net/). 
Considering this list was peer-reviewed by the SAB and found to be 
acceptable,\10\ we believe it to be reasonable for use in risk 
assessments for the RTR program.
---------------------------------------------------------------------------

    \10\ 10 Refer to the May 2010, SAB response to the EPA 
Administrator (EPA-SAB-10-007); http://www.regulations.gov/#!documentDetail;D=EPA-HQ-OAR-2011-0797-0075
---------------------------------------------------------------------------

    Regarding the commenter's assertion that we did not base the 
multipathway risk assessment on allowable emissions, we believe it is 
reasonable for the multipathway risk assessment to be based on actual 
emissions for this source category, and not the allowable level of 
emissions--i.e. the level that facilities are permitted to emit. The 
potline fugitive emissions, which drive the risks associated with this 
source category, vary in magnitude and location along the roofline due 
to normal operations, including, among others, replacement of anodes. 
We exacerbate the uncertainty associated with these variations in 
fugitive emissions when we scale up actual emissions to estimate 
allowable emissions. Also, there is considerable uncertainty associated 
with estimated allowable emissions from batch operations, such as pitch 
storage tank and pitch production, due to the nature of batch 
operations (e.g., estimating the number of batch operations possible or 
necessary during a period of time). Further uncertainty results when we 
consider that, in order to comply with the emission limits at all 
times, a source's allowable emissions would need to be below the 
associated standard by an indeterminate amount during normal 
operations. Therefore, we conclude that the uncertainties associated 
with the multipathway screen along with uncertainties in the allowable 
emissions estimates would make a multipathway risk assessment based on 
allowable emissions highly uncertain and, thereby, not appropriate for 
use in making this regulatory decision.
    The commenter also argued for summing acute HQs from different HAP 
to assess acute non-cancer risk. We do not sum results of the acute 
non-cancer inhalation assessment to create a combined acute risk number 
that would represent the total acute risk for all pollutants that act 
in a similar way on the same organ system or systems (similar to the 
chronic TOSHI). The worst-case acute screen is already a conservative 
scenario. That is, the acute screening scenario assumes worst-case 
meteorology, peak emissions for all emission points occurring 
concurrently and an individual being located at the site of maximum 
concentration for an hour. Thus, as noted in the Residual Risk 
Assessment for the Primary Aluminum Production Source Category in 
Support of the September 2015 Risk and Technology Review Final Rule, 
page 31, which is available in the docket for this action (Docket ID 
No. EPA-HQ-OAR-2011-0797), ``because of the conservative nature of the 
acute inhalation screening and the variable nature of emissions and 
potential exposures, acute impacts were screened on an individual 
pollutant basis, not using the TOSHI approach.'' The EPA may conduct a 
reasoned screening assessment without having to adopt the most 
conceivably conservative assumption for each and every part of the 
analysis.
    Comment: One commenter stated that, as the EPA recognized in the 
secondary aluminum proposal, at least nine secondary aluminum 
facilities have co-located primary aluminum operations. The commenter 
stated that for both source categories, the EPA found that the 
facility-wide MIR is 70-in-1 million, driven by As, Ni, and hexavalent 
chromium, and that the TOSHI (chronic non-cancer risk) is 1, driven by 
cadmium. The commenter stated that the TOSHI number appears to consider 
only inhalation risk and stated that the TOSHI number must be viewed in 
context, as the EPA is aware that scientists have directed the EPA to 
do (and as previously explained and cited to the EPA in comments). The 
commenter stated that if considered in combination with the high 
secondary aluminum multipathway risk, and with the high inhalation and 
multipathway risks for primary aluminum, the facility-wide cancer risk 
provides additional evidence that risks from both source categories are 
unacceptable. The commenter asserts this is the case because the most-
exposed person's full amount of risk is the combined amount from the 
co-located primary and secondary aluminum, not just each source 
category separately. The commenter stated that it would be unlawful and 
arbitrary to consider each type of risk separately, when people near 
both sources are exposed to both kinds of risk at the same time and, 
thus, face a higher overall amount of risk.
    The commenter stated that the EPA has not offered and can not offer 
a valid justification for not finding risk from both source categories 
(including primary aluminum prebake and secondary aluminum) to be 
unacceptable based on the co-located and combined risks. The commenter 
stated that the EPA has collected data from both source categories and 
is evaluating that data in rulemakings for both source categories. The 
commenter stated that the EPA may not lawfully ignore the full picture 
of risk that its combined rulemakings show is present

[[Page 62403]]

for people exposed simultaneously to both source categories at the same 
facility.
    The commenter stated that the EPA only assessed facility-wide risks 
based on so-called ``actual'' emissions, so the facility-wide risk 
number could be at least 1.5 to 3 times higher, based on the EPA's 
recognition that allowable emissions from primary aluminum facilities 
are about 1.5 to 1.9 times higher and the fact that allowable emissions 
from secondary aluminum are at least 3 times higher.
    The commenter stated that it is important that the EPA is 
evaluating facility-wide risk from sources in multiple categories that 
are co-located.
    The commenter stated that the EPA may not reasonably or lawfully 
then decide not to use the results of that assessment to set stronger 
standards for these sources. The commenter stated that this rulemaking 
is an important opportunity for the EPA to recognize the need to act 
based on data showing significant combined and cumulative risks and 
impacts at the facility-wide level. The commenter stated that the EPA 
is also required to do so to meet its CAA section 112(f)(2) duties, as 
explained in the 2012 comments and reincorporated by reference here.
    Response: We agree with the commenter that facility-wide risk 
assessment is appropriately considered in putting the source category 
risks in context. However, we disagree with the comment that we failed 
to appropriately consider or account for cumulative risk.
    We conducted facility-wide risk assessments for all major sources 
in the source category that were operating in 2014, including the nine 
secondary aluminum production facilities co-located with primary 
aluminum reduction plants. See 79 FR 72929 (emissions estimated for all 
emitting sources in a contiguous area under common control).
    The commenter stated that the EPA must find the risks unacceptable 
based on the whole-facility risks from co-located primary and secondary 
aluminum operations. The EPA does not typically include whole-facility 
assessments in the CAA section 112(f) acceptability determination for a 
source category. Reasons for this include the fact that emissions and 
source characterization data are usually not of the same vintage and 
quality for all source categories that are on the same site, and, thus, 
the results of the whole-facility assessment are generally not 
appropriate to include in the regulatory decisions regarding 
acceptability. However, in this case, we are developing the risk 
assessments for primary and secondary aluminum production at the same 
time. The data are generally of the same vintage and we have actual 
emissions data and source characterization data for both source 
categories. In response to the comment, we refer to the facility-wide 
risk assessment, which included the nine facilities with co-located 
primary and secondary aluminum operations. As discussed above and shown 
in Table 6, for the facility with the highest risk from inhalation, the 
facility-wide MIR for cancer from actual emissions is 70-in-1 million. 
The facility-wide non-cancer hazard is 1. The highest facility-wide 
exceedance of the multipathway screen is 70. There was no facility-wide 
exceedance of a noncancer threshold in the multipathway screen. 
Considering these facility-wide results as part of the acceptability 
determination is thus corroborative of our determination that the risks 
are acceptable for the Secondary Aluminum Production source category.
    The commenter is correct that we based our facility-wide risk 
assessment on actual emissions rather than on estimated allowable 
emissions. Because the facility-wide allowable emissions estimates have 
not been subjected to the same level of scrutiny, quality assurance, 
and technical evaluation as the actual emissions estimates from the 
source category, and because of the larger inherent uncertainty 
associated with allowable emissions discussed above, facility-wide risk 
results based on allowable emissions would be too uncertain to support 
a regulatory decision, but they could remain important for providing 
context as long as their uncertainty is taken into consideration.
    The distinct issue of whether background emissions not associated 
with co-located emitting sources at the facility is discussed above. We 
reiterate that while the incorporation of additional background 
concentrations from the environment in our risk assessments (including 
those from mobile sources and other industrial and area sources) could 
be technically challenging, they are neither mandated nor barred from 
our analysis. In developing the decision framework in the Benzene 
NESHAP used for making residual risk decisions, the EPA rejected 
approaches that would have mandated consideration of background levels 
of pollution in assessing the acceptability of risk, concluding that 
comparison of acceptable risk should not be associated with levels in 
polluted urban air (54 FR 38044, 38061, September 14, 1989).
    Background levels (including natural background) are not barred 
from the EPA's ample margin of safety analysis, and the EPA may 
consider them, as appropriate and as available, along with other 
factors, such as cost and technical feasibility, in the second step of 
its CAA section 112(f) analysis. As discussed in the 2014 supplemental 
proposal, the risk assessment for this source category did not include 
background contributions (that may reflect emissions that are from 
outside the source category and from other than co-located sources) 
because the available data are of insufficient quality upon which to 
base a meaningful analysis.
    Comment: Some commenters recommended that the EPA should proceed 
with the required full multipathway risk assessment, as the data showed 
that the persistent and bioaccumulation screening emission rates were 
exceeded for POM. The commenters do not believe the risk analysis for 
this source category is final until this step is complete and disagree 
with the EPA's explanation that the results are biased high and subject 
to significant uncertainties, arguing that the EPA cannot ignore the 
implications of this screening assessment. The commenter recommended 
that the EPA perform a full multipathway assessment to find a number it 
believes fully represents this risk, or use the number it has created 
as the best available number, without discounting the impact of that 
number.
    One commenter recommended conducting a full multipathway risk 
assessment for this source category that includes consideration of a 
child's multipathway exposure in urban and rural residential scenarios. 
The commenter further stated that the failure of the EPA to assess an 
exposed child scenario as part of the cumulative risk assessment 
ignores the exposures that may pose the most significant risk from this 
source category. The commenter highlighted the risk to children from 
contaminated soils, noting that past risk assessments have relied on 
outdated estimates of incidental soil ingestion exposures and stated 
that the EPA must update these values. The commenter cited two EPA 
exposures factors handbooks and a journal article as resources to use 
for assessing risks.
    Response: We disagree with the comment that our multipathway risk 
assessment does not consider children. The multipathway screening 
scenario is intended to represent a high-end exposure for children via 
incidental soil ingestion. The 2011 Exposure Factors Handbook 
recommended ``upper-percentile'' soil ingestion rate (numeric 
percentile not specified) for children aged 3 to 6 years is 200 
milligrams per

[[Page 62404]]

day (mg/d). The EPA also published the Child-Specific Exposure Factors 
Handbook (2008). No additional data or recommendations for child soil 
ingestion are presented in this source, and, in fact, an ``upper 
percentile'' value for this parameter is not provided. Based on these 
sources, a value of 200 mg/d is used in the current RTR multipathway 
screening scenario for the child incidental soil ingestion rate.
    The multipathway risk assessment conducted for the proposal was a 
screening-level assessment. The screening assessment used highly 
conservative assumptions designed to ensure that facilities with 
results below the screening threshold values did not have the potential 
for multipathway impacts of concern. The screening scenario is a 
hypothetical scenario, and, due to the theoretical construct of the 
screening model, exceedances of the thresholds are not directly 
translatable into estimates of risk or HQs for these facilities. The 
scope of the assessment did not change across the tiers in the 
multipathway screening assessment and is described in the risk 
assessment documents (and related appendices) available in the docket 
for this rulemaking (Docket ID No. EPA-HQ-OAR-2011-0797).
4. What is the rationale for our final approach and final decisions for 
the risk review?
    As discussed above and in the preamble of the 2014 supplemental 
proposal, after considering health risk information and other factors, 
including uncertainties, we have determined that the risks from primary 
aluminum production prebake facilities are acceptable and that the 
current NESHAP provides an ample margin of safety to protect public 
health for prebake facilities given that the inhalation cancer MIR was 
well below 100-in-1 million, the chronic non-cancer risks were low, and 
the multipathway assessment indicated the maximum cancer risk due to 
multipathway exposures to HAP emissions from prebake facilities was no 
higher than 50-in-1 million. In summary, our revised risk assessment 
indicates that cancer risks due to actual and allowable emissions from 
prebake facilities are below the presumptive limit of acceptability, 
and that non-cancer results indicate minimal likelihood of adverse 
health effects. We evaluated potential risk reductions as well as the 
cost of control options, but did not identify any control technologies 
or other measures that would be cost-effective in further reducing 
risks (or potential risks) for prebake facilities. In particular, we 
did not identify any cost-effective approaches to further reduce As, 
Ni, and PAH emissions and risks beyond what is already being achieved 
by the current NESHAP.
    Regarding the Soderberg facilities, as discussed above, since all 
existing Soderberg facilities are permanently shut down, we necessarily 
conclude the risks due to emissions from Soderberg facilities are 
currently acceptable. However, under our ample margin of safety 
analysis, we have determined that it is appropriate to promulgate 
standards for Ni, As, and PAH under CAA section 112(f) for the 
Soderberg subcategory potlines to ensure that excess cancer risk due to 
HAP emissions from any possible future primary aluminum reduction plant 
would remain below 100-in-1 million. We estimate the costs to comply 
with these standards for Soderberg facilities would be zero since there 
are no existing operating Soderberg facilities in the U.S. Furthermore, 
we expect any future new primary aluminum reduction plant would use 
prebake potlines since prebake potlines are more energy efficient (and 
lower-emitting) than Soderberg potlines. Therefore, we also estimate 
that these standards would pose no cost for any future new primary 
aluminum reduction plant.

B. CAA Sections 112(d)(2) and (3) Revisions for the Primary Aluminum 
Production Source Category

1. What did we propose pursuant to CAA sections 112(d)(2) and (3) for 
the Primary Aluminum Production source category?
    We proposed several MACT standards in the December 2011 proposal 
pursuant to CAA sections 112(d)(2) and (3), which are summarized in 
Table 7, below.
    We received significant comments on the 2011 proposal from industry 
representatives, environmental organizations, and state regulatory 
agencies. After reviewing the comments, and after consideration of 
additional data and information received since the 2011 proposal, the 
EPA determined it was appropriate to gather additional data, revise 
some of the analyses associated with that proposal, and to publish a 
supplemental proposal.
    In support of the supplemental proposal, the EPA sent an 
information request to owners of currently operating primary aluminum 
reduction plants in March of 2013. The EPA received associated 
responses in May through August 2013. As part of this data collection 
effort, we received emissions data for PM, HAP metals (including 
antimony, As, beryllium, cobalt, manganese, selenium, Ni, cadmium, 
chromium, lead, and Hg), PCB, and D/F from potlines, anode bake 
furnaces, and/or paste production plants from every primary aluminum 
reduction plant that was operational at that time, including nine 
prebake-type facilities and one Soderberg-type facility.
    Based on evaluation of all the data, we proposed several revised 
and new MACT standards in the December 2014 proposal pursuant to CAA 
sections 112(d)(2) and (3), which are summarized in Table 7, below.

                                   Table 7--Summary of Proposed MACT Standards
----------------------------------------------------------------------------------------------------------------
                                                                                             Promulgated MACT
              Proposal                           HAP                      Source                 standard
----------------------------------------------------------------------------------------------------------------
2011 proposal (76 FR 76259)........  COS........................  New potlines..........  3.1 lb/ton aluminum
                                                                  Existing potlines.....   produced.
                                                                                          3.9 lb/ton aluminum
                                                                                           produced.
                                     POM........................  New potlines..........  0.62 lb/ton aluminum
                                                                                           produced.
                                                                  Existing potlines.....
                                                                  CWPB1.................  0.62 lb/ton aluminum
                                                                                           produced.
                                                                  CWPB2.................  1.3 lb/ton aluminum
                                                                                           produced.
                                                                  CWPB3.................  1.26 lb/ton aluminum
                                                                                           produced.
                                                                  SWPB..................  0.65 lb/ton aluminum
                                                                                           produced.
                                                                  VSS2..................  3.8 lb/ton aluminum
                                                                                           produced.
                                                                  HSS...................  3.0 lb/ton aluminum
                                                                                           produced.
                                                                  Existing pitch storage  Minimum 95-percent
                                                                   tanks.                  reduction of inlet
                                                                                           POM emissions.
2014 proposal (79 FR 72914)........  POM........................  New potlines..........  0.77 lb/ton aluminum
                                                                                           produced.
                                                                  Existing potlines.

[[Page 62405]]

 
                                                                  CWPB1.................  1.1 lb/ton aluminum
                                                                                           produced.
                                                                  CWPB2.................  12 lb/ton aluminum
                                                                                           produced.
                                                                  CWPB3.................  2.7 lb/ton aluminum
                                                                                           produced.
                                                                  SWPB..................  19 lb/ton aluminum
                                                                                           produced.
                                     PM.........................  New potlines..........  4.6 lb/ton aluminum
                                                                                           produced.
                                                                  Existing potlines.
                                                                  CWPB1.................  7.2 lb/ton aluminum
                                                                                           produced.
                                                                  CWPB2.................  11 lb/ton aluminum
                                                                                           produced.
                                                                  CWPB3.................  20 lb/ton aluminum
                                                                                           produced.
                                                                  SWPB..................  4.6 lb/ton aluminum
                                                                                           produced.
                                                                  VSS2..................  26 lb/ton aluminum
                                                                                           produced.
                                                                  New anode bake furnace  0.036 lb/ton of green
                                                                                           anode produced.
                                                                  Existing anode bake     0.068 lb/ton of green
                                                                   furnace.                anode produced.
                                                                  New paste production    0.0056 lb/ton of paste
                                                                   plant.                  produced.
                                                                  Existing paste          0.082 lb/ton of paste
                                                                   production plant.       produced.
----------------------------------------------------------------------------------------------------------------
HSS = horizontal stud Soderberg.

2. How did the proposed CAA sections 112(d)(2) and (3) standards change 
for the Primary Aluminum Production source category?
    Commenters provided additional emissions data for POM from SWPB 
potlines and for PM from CWPB1 potlines and anode bake furnaces, and 
identified areas where we had misinterpreted data used for the proposed 
PM and POM standards.
    Based on these comments and additional PM and POM emissions data, 
we re-evaluated the proposed PM and POM MACT standards and revised the 
following MACT limits:
     POM emission limit of 19 lb/ton aluminum for existing SWPB 
potlines changed to 17 lb/ton aluminum;
     PM emission limit of 7.2 lb/ton aluminum for existing 
CWPB1 potlines changed to 7.4 lb/ton aluminum;
     PM emission limit of 4.6 lb/ton aluminum for existing SWPB 
potlines changed to 4.9 lb/ton aluminum;
     PM emission limit of 4.6 lb/ton aluminum for new potlines 
changed to 4.9 lb/ton aluminum;
     PM emission limit of 0.068 lb/ton green anode for existing 
anode bake furnaces changed to 0.2 lb/ton green anode; and
     PM emission limit of 0.036 lb/ton green anode for new 
anode bake furnaces changed to 0.07 lb/ton green anode.
    The EPA discussed at proposal whether to promulgate MACT standards 
at this time for HAP where much, most, or virtually all of the data 
showed levels below detection limits. See 79 FR 72936. We received 
comments claiming that, in addition to the standards listed above, the 
EPA must promulgate standards for these HAP: Hg, D/F, and PCB. Based on 
these comments, and considering further reply comments from industry 
addressing this issue (see email, dated July 1, 2015, from Mr. Curt 
Wells of The Aluminum Association, which is available in the docket for 
this rulemaking (Docket ID No. EPA-HQ-OAR-2011-0797)), we re-evaluated 
the data we had for PCB, D/F, and Hg to determine whether it would be 
appropriate to establish emissions limits for these HAP. Based on that 
evaluation, we determined that the emissions data for PCB from VSS2 
Soderberg potlines are above detection limits and that numerical limits 
reflecting MACT can be set for these sources. Therefore, we are 
finalizing a MACT limit for PCB of 2.0 [micro]g TEQ/ton for existing 
Soderberg VSS2 potlines and new Soderberg potlines. These standards 
were developed based on the 99-percent upper prediction limit (UPL) for 
PCB emissions from the available emissions data and represent the MACT 
floor level of control. We also considered beyond-the-floor options, 
but did not identify any feasible or cost-effective beyond-the-floor 
options.
    Furthermore, we determined that the emissions data for Hg from 
anode bake furnaces are above detection limits and that MACT limits can 
be set for these sources. Therefore, we are finalizing a MACT limit for 
Hg of 1.7 [mu]g/dscm for new and existing anode bake furnaces. These 
standards are equal to 3 times the representative detection limit (RDL) 
value for Hg. The RDL is the average method detection level (MDL) 
achieved in practice by laboratories whose data support the best 
performing 12 percent of a MACT category (or categories). We use an 
average value for the RDL because a decision for a new source floor may 
be based upon a test report where the laboratory chosen has better 
equipment and/or practices than other laboratories and, therefore, 
reported a lower MDL. Using that data to set the floor would result in 
requiring all new sources to choose that laboratory in order to 
demonstrate compliance with the new limit. We recognize the need to 
allow sources to conduct business with their local laboratories, or a 
laboratory of their preference; however, we limit the RDL to the best 
laboratory performers because we do not want to incentivize the use of 
the worst performing laboratories. The EPA policy is to set MACT 
standards for a pollutant at a level of 3 times the RDL level for that 
pollutant when the 99-percent UPL value for the available emissions 
data results in a value that is less than 3 times the RDL level for 
that pollutant, which is the case for Hg emissions from anode bake 
furnaces. See, e.g., docket item number EPA-HQ-OAR-2009-0559-0157.
    We use the multiplication factor of 3 to approximately reduce the 
imprecision of the analytical method until the imprecision in the field 
sampling reflects the relative method precision as estimated by the 
American Society of Mechanical Engineers (ASME) study \11\ that also 
indicates that such relative imprecision, from 10 to 20 percent, 
remains constant over the range of the methods. For comparing to the 
floor, if 3 times the RDL were less than the calculated floor or 
emissions limit (e.g., calculated from the UPL), we would conclude that 
measurement variability was adequately addressed. The calculated floor 
or emissions limit would need no adjustment. If, on the other hand, the 
value equal to 3 times the RDL were greater than the UPL, we would 
conclude that the calculated floor or emissions limit does not account 
entirely for measurement variability.

[[Page 62406]]

Therefore, we substituted the value equal to 3 times the RDL for the 
calculated floor or emissions limit which results in a concentration 
where the method would produce measurement accuracy on the order of 10 
to 20 percent similar to other EPA test methods and the results found 
in the ASME study.
---------------------------------------------------------------------------

    \11\ Reference Method Accuracy and Precision (ReMAP): PHASE 1, 
Precision of Manual Stack Emission Measurements; American Society of 
Mechanical Engineers, Research Committee on Industrial and Municipal 
Waste, February 2001.
---------------------------------------------------------------------------

    Please refer to the Final MACT Floor Analysis for the Primary 
Aluminum Production Source Category, which is available in the docket 
for this rulemaking (Docket ID No. EPA-HQ-OAR-2011-0797), for more 
information regarding the new standards.
    Regarding the Hg and PCB emissions from the other process units 
(such as potlines and paste production plants), and D/F from all the 
process units, most (or all) of the emissions tests were below the 
detection limit. Therefore, we conclude it is not feasible to prescribe 
or enforce a numerical emission standard for these HAP emissions, 
within the meaning of CAA section 112(h)(1) and (2). Specifically, 
measured values for these HAP would be neither duplicable nor 
replicable and would not give reliable indication of what (if anything) 
the source was emitting. Under CAA section 112(h)(2), the EPA may adopt 
work practice standards when ``the application of measurement 
methodology to a particular class of sources is not practicable due to 
technological and economic limitations.'' As discussed more fully in 
section IV.C below, the EPA does not regard measurements which are 
unreliable, non-duplicable, and non-replicable to be practicable. 
Simply put, the CAA simply does not compel promulgation of numerical 
emission standards that are too unreliable to be meaningful. Therefore, 
as discussed in section IV.C of this preamble, we are promulgating work 
practice standards for these HAP under section 112(h) of the CAA for 
various process units.
3. What key comments did we receive on the CAA sections 112(d)(2) and 
(3) proposed revisions, and what are our responses?
    Comment: Commenters identified POM and PM emissions data from 
prebake potlines and PM emissions data from anode bake furnaces that 
were incorrectly represented in the data sets used for MACT limit 
determinations. Commenters also provided additional PM data for prebake 
potlines and anode bake furnaces. Commenters requested the EPA to re-
evaluate MACT floors and recalculate MACT limits for PM and POM based 
on the corrected and additional data.
    Response: We agree with commenters that the EPA misinterpreted 
certain data in the supplemental proposal. For example, we 
misinterpreted the PM and POM emissions from a single exhaust stack of 
a control device with multiple exhaust stacks to be the total PM and 
POM emissions from that source and misinterpreted the primary POM 
emissions from a potline to be total POM emissions from that potline 
(see pages 5 through 8 of the public comments provided by The Aluminum 
Association, which are available in the docket for this rulemaking 
(Docket ID No. EPA-HQ-OAR-2011-0797). The final rule reflects 
appropriate data corrections, and the additional data provided have 
been incorporated in the final limits promulgated for POM and PM from 
prebake potlines and PM from anode bake furnaces. Further information 
regarding the development of the final emission limits can be found in 
the document titled, Final MACT Floor Analysis for the Primary Aluminum 
Production Source Category, which is available in the docket for this 
action.
    Comment: One commenter stated that the EPA must set standards for 
all HAP emitted by primary aluminum reduction plants. The commenter 
explained that the EPA's data collection found that primary aluminum 
reduction plants emit D/F, Hg, and PCB. Nevertheless, the EPA proposed 
not to set standards to limit these pollutants at all because ``many of 
the emissions tests were below detection limit'' even though there are 
emissions data in the record above the detection limits for these 
pollutants for some sources. The commenter continued their argument by 
stating that the CAA and D.C. Circuit case law require the EPA to set 
limits for all emitted pollutants. As the D.C. Circuit has held, the 
EPA has a ``clear statutory obligation to set emissions standards for 
each listed HAP [i.e., hazardous air pollutant]'' under CAA section 
112.
    Response: As explained above, based on consideration of this 
comment, industry comment, and re-evaluation of the data, we are 
promulgating numerical emissions limits for Hg from anode bake furnaces 
and PCB for Soderberg potlines because the data we have support the 
development of such numerical limits. Furthermore, regarding Hg, D/F, 
and PCB from the other process units, as described in section IV.C of 
this preamble, we are promulgating work practice standards under CAA 
section 112(h) because most of the emissions data were below the 
detection limit for these HAP and process units.
4. What is the rationale for our final approach for the CAA sections 
112(d)(2) and (3) revisions?
    All numerical MACT standards proposed and promulgated for the 
Primary Aluminum Production source category reflect the MACT floor and 
were developed based on the 99-percent UPL of the available emissions 
data for this source category,\12\ except for the limits set for Hg 
emissions from anode bake furnaces which were set equal to a value of 3 
times the RDL due to data limitations, as explained above. We 
considered beyond-the-floor options. However, we determined that no 
cost-effective beyond-the-floor options were available. For more 
information regarding the development of the MACT standards for this 
source category and our analyses of beyond-the-floor options, see the 
document, Final MACT Floor Analysis for the Primary Aluminum Production 
Source Category, which is available in the docket for this action 
(Docket ID No. EPA-HQ-OAR-2011-0797).
---------------------------------------------------------------------------

    \12\ For determining performance over time, the EPA used the UPL 
statistical methodology. That is, the best performers, and their 
level of performance, are determined after accounting for sources' 
normal operating variability. The UPL represents the value which one 
can expect the mean of a specified number of future observations 
(e.g., 3-run average) to fall below for the specified level of 
confidence, based upon the results of an independent sample from the 
same population. See MACT Floor Memo and Memorandum, Use of the 
Upper prediction limit for Calculating MACT Floors (Docket ID No. 
EPA-HQ-OAR-2011-0797).
---------------------------------------------------------------------------

C. Revisions to the Work Practice Standards for the Primary Aluminum 
Production Source Category

1. What work practice standards did we propose pursuant to CAA sections 
112(h) and/or 112(d)(6) for the Primary Aluminum Production source 
category?
    In 2011, we proposed work practice standards for TF and POM 
emissions from potlines during startup periods under 112(h) of the CAA 
because we determined that it is economically and technically 
infeasible to measure emissions of these HAP during these startup 
periods. Subsequently, in 2014 we proposed to expand these standards to 
also apply to PM.
    In 2014, we also realized that these work practices could also help 
minimize emissions during periods of normal operation. Therefore, as 
mentioned above, under the technology review pursuant to CAA section 
112(d)(6), in 2014 we proposed that these work practice standards for 
potlines would also apply during normal operations to ensure improved 
capture and control of TF, POM, and

[[Page 62407]]

PM emissions from those sources. For potlines, the work practices 
included: (1) Ensuring the potline scrubbers and exhaust fans are 
operational at all times; (2) ensuring that the primary capture and 
control system is operating at all times; (3) keeping pots covered as 
much as practicable to include, but not limited to, minimizing the 
removal of covers or panels of the pots on which work is being 
performed; and (4) inspecting potlines daily.
    Regarding other emissions sources, in 2011 we also proposed work 
practices for anode bake furnaces during startup periods under CAA 
section 112(d)(6) that will ensure improved capture and control of HAP 
emissions from those sources during startup periods. Then, in the 2014 
supplemental proposal, we proposed work practices for paste production 
plants during startup periods under CAA section 112(d)(6) that will 
ensure improved capture and control of HAP emissions from those sources 
during startup periods.
    For anode bake furnaces and paste production plants, the proposed 
work practices included ensuring that the associated emission control 
system is operating within normal parametric limits prior to startup of 
the emission source and requiring that the anode bake furnace or paste 
production plants be shut down if the associated emission control 
system is off line during startup.
2. What changes were made to the work practice standards developed for 
the Primary Aluminum Production source category pursuant to CAA 
sections 112(h) and/or 112(d)(6)?
    In the final rule, the work practices for potlines, anode bake 
furnaces, and paste production plants remain unchanged from the 
proposals. In the final rule, we added additional, more specific VE 
monitoring requirements, which are applicable during all periods of 
operation, for emission points that are not equipped with BLDS or PM 
CEMS, and thus, ensuring improved capture and control of emissions at 
all times. Furthermore, the work practice standards for anode bake 
furnaces address PCB emissions (under CAA section 112(h)) for these 
process units, and the work practice standards for potlines address Hg 
from all potlines, PCB emissions from prebake potlines, and D/F 
emissions from Soderberg potlines (under CAA section 112(h)) because in 
all these cases we determined that it is economically and technically 
infeasible to reliably measure emissions of these HAP from these 
process units.
3. What key comments did we receive regarding work practice standards 
and what are our responses?
    Comment: As mentioned above, one commenter stated that the EPA's 
data collection found that primary aluminum reduction plants emit D/F, 
Hg, and PCB. The commenter stated that the EPA states that it is not 
proposing standards for these currently unregulated pollutants because 
``many of the emissions tests were below detection limit.'' The 
commenter stated that the EPA has some emission data in the record 
above the detection limits for these pollutants for some sources. The 
commenter stated that the CAA and D.C. Circuit case law require the EPA 
to set limits for all emitted pollutants.
    The commenter stated that as the D.C. Circuit has held, the EPA has 
a ``clear statutory obligation to set emissions standards for each 
listed HAP [i.e., hazardous air pollutant]'' under CAA sections 
112(d)(1)-(3). The commenter stated that these pollutants are some of 
the most potent and most harmful, even at extremely low levels of human 
exposure.
    The commenter stated that it would be internally inconsistent not 
to regulate these HAP, because in this rulemaking, the EPA has 
recognized the need to set emission standards for unregulated 
pollutants. The commenter stated that the EPA states that it may, but 
is not required to set emission standards for these pollutants, citing 
the Portland Cement decision (665 F.3d at 189). The commenter stated 
that the Portland Cement decision did not hold that the EPA may avoid 
setting limits for CAA section 112-listed pollutants emitted by a 
source category. The commenter stated that the Portland Cement decision 
affirmed that the EPA may set revised emission standards, including 
updated MACT floors, whenever it determines this is necessary, 
including as a result of a CAA section 112(d)(6) review, or more often.
    The commenter stated that the revised standards the EPA is 
proposing here must satisfy CAA sections 112(d)(2)-(3). The commenter 
stated that the EPA may not ``cherry-pick'' the HAP when initially 
setting and revising standards. The commenter stated that if the EPA 
missed HAP that it is legally required to regulate in prior standards, 
then it has an ongoing obligation to set such standards, and it would 
be both unlawful and arbitrary and capricious for the EPA not to set 
such standards as part of this review and revision rulemaking under CAA 
section 112(d).
    The commenter stated that the EPA has recognized the need to assess 
health risks from these pollutants and has created a method to do so by 
assuming that the undetected emissions were equal to one-half the 
detection limit, which the EPA explains is ``the established approach 
for dealing with non-detects in the EPA's RTR program when developing 
emissions estimates for input to the risk assessments.'' The commenter 
stated that the EPA may not ignore these pollutants under CAA section 
112(d) when it acknowledges and has found a way to address them under 
CAA section 112(f)--even though some of the data in the record are 
below the detection level.
    The commenter stated that instead of ignoring the emissions data it 
has, the EPA must at least use the emission data that are above the 
detection level to set standards. Furthermore, the commenter stated 
that for the non-detect values, the EPA may not lawfully ignore these 
data. The commenter stated that the EPA must recognize that some 
sources have achieved levels of emissions below the detection level and 
use an appropriate number at or below the detection level as part of 
its floor analysis, to satisfy the floor and beyond-the-floor 
requirements of CAA sections 112(d)(2)-(3).
    Response: As mentioned in section IV.B above, based on 
consideration of this comment, industry comment, and re-evaluation of 
the data, we are promulgating numerical emissions limits for Hg from 
anode bake furnaces and PCB from Soderberg potlines because the data we 
have support the development of such numerical limits. Furthermore, 
regarding Hg from potlines, PCB from prebake potlines and anode bake 
furnaces, and D/F from Soderberg potlines, as described in section IV.C 
of this preamble, we are promulgating work practice standards under CAA 
section 112(h) because most of the emissions data were below the 
detection limits for these HAP and process units. However, EPA is not 
adopting either numerical standards or work practice standards for 
these HAP from other process units because all of the associated 
emissions data were below the detection limit or otherwise unreliable 
(e.g., the test report indicated quality assurance problems). There is 
certainly no obligation under CAA sections 112(d)(2) and (3) for the 
EPA to promulgate standards for HAP that are not emitted by a source 
category.
    Given these determinations, the commenter's claims that the EPA is 
obligated to establish MACT standards for HAP at particular times, and 
that it must do so if it is making assumptions about emission levels as 
part of the CAA

[[Page 62408]]

section 112(f) risk analysis, are no longer presented.\13\
---------------------------------------------------------------------------

    \13\ We disagree with the commenter that standards are compelled 
at this time, given the EPA's discretion regarding timing of 
revising MACT standards. See 79 FR 72936 at n. 35. The EPA is 
exercising its discretion in adopting these standards in the final 
rule.
---------------------------------------------------------------------------

4. What is the rationale for our final approach regarding work practice 
standards under CAA sections 112(h) and/or 112(d)(6)?
    Based on comments received during the 2014 supplemental proposal 
public comment period, we determined that it was appropriate to re-
evaluate the data we had for PCB, D/F, and Hg. For D/F from potlines, 
anode bake furnaces, and paste production plants; Hg from potlines and 
paste production plants; and PCB from prebake potlines, anode bake 
furnaces, and paste production plants, we found that more than half of 
the test data were below the detection limit. We maintain our December 
2014 proposed position that it is not appropriate to promulgate 
numerical MACT limits for these HAP from these process units. Instead, 
as explained below, we are promulgating work practice standards under 
CAA section 112(h), when appropriate.
    Sections 112(h)(1) and (h)(2)(B) of the CAA indicate that the EPA 
may adopt a work practice standard rather than a numeric standard when 
``the application of measurement methodology to a particular class of 
sources is not practicable due to technological and economic 
limitations.'' As explained above, the majority of the data collected 
for Hg, D/F, and PCB during the information request test program for 
these emissions points were below the detection limit. Under these 
circumstances, the EPA does not believe that it is technologically and 
economically practicable to reliably measure Hg, D/F, and PCB emissions 
from these particular sources. The ``application of measurement 
methodologies'' (described in CAA section 112(h)(2)(B)) means more than 
taking a measurement. It must also mean that a measurement has some 
reasonable relation to what the source is emitting, i.e., that the 
measurement yields a meaningful value. That is not the case here, and 
the EPA, therefore, does not believe it reasonable to establish a 
numerical standard for Hg, D/F, and PCB from these particular process 
units in this rule. Moreover, a numerical limit established at some 
level greater than the detection limit (which would be a necessity 
since any numeric standard would have to be measurable) could actually 
authorize and allow more emissions of these HAP than would otherwise be 
the case. The work practices for anode bake furnaces, paste production 
plants, and potlines discussed in section IV.C.1 of this preamble are 
those practices utilized by the best performing sources--the sources 
with the work practices in place that the EPA has evaluated as best 
controlling emissions of these HAP.
    In the cases of PCB from anode bake furnaces and prebake potlines, 
D/F from Soderberg potlines, and Hg from both Soderberg and prebake 
potlines, we determined that about 70 to 80 percent of the emissions 
data were below the detection limits. In previous cases (see, e.g., 76 
FR 25046, 78 FR 22387, and docket item number EPA-HQ-OAR-2013-0291-
0120) where test results were predominantly (e.g., more than 55 percent 
of the test run results) found to be below detection limits, the EPA 
established work practice standards for the pollutants in question from 
the subject sources, since we believe emissions of the pollutants are 
too low to reliably measure and quantify. We are adopting that same 
approach here, for the same reasons, and are, therefore, finalizing 
work practice standards to address emissions of Hg from potlines, PCB 
from anode bake furnaces and prebake potlines, and D/F from Soderberg 
potlines. Specifically, we are finalizing the work practice standards 
presented in 40 CFR 63.847(l) and (m) and 40 CFR 63.854 of the 2014 
supplemental proposal to address emissions of Hg from potlines, D/F 
from Soderberg potlines, and PCB from prebake potlines. Further, the 
requirements of 40 CFR 63.847(h)(1) and 40 CFR 63.848(f)(1) of current 
subpart LL; the work practice standards proposed in sections 40 CFR 
63.843(f) and 40 CFR 63.844(f) of the 2011 proposal and 40 CFR 
63.847(l) of the 2014 proposal; and the enhanced VE monitoring of 40 
CFR 63.848(g)(3) of the final rule address the PCB emissions from anode 
bake furnaces.
    However, as noted above, all of the emissions data for D/F from 
prebake potlines, anode bake furnaces, and paste production plants were 
either below the detection limit or otherwise unreliable (e.g., were 
flagged in the test report as having quality assurance issues). 
Therefore, we are not promulgating numerical emissions limits or work 
practices for these HAP since there is no reliable evidence that these 
sources emit them.

D. What changes did we make to the control device monitoring 
requirements for the Primary Aluminum Production source category?

1. What control device monitoring requirements did we propose for the 
Primary Aluminum Production source category?
    In the 2014 supplemental proposal, we proposed that the owner or 
operator of a primary aluminum reduction plant would need to install 
either a BLDS or a PM CEMS on the exhaust of each control device used 
to control emissions from a new or existing affected potline, anode 
bake furnace, or paste production plant.
2. What changes did the EPA make to the proposed control device 
monitoring requirements developed for the Primary Aluminum Production 
source category?
    In the final rule, the control device monitoring requirements for 
new potlines, new anode bake furnaces, and new paste production plants 
remain unchanged. However, for existing potlines, existing anode bake 
furnaces and existing paste production plants, the owner or operators 
have the option to conduct enhanced VE monitoring as an alternative to 
the installation of BLDS or PM CEMS. This enhanced VE monitoring would 
include twice daily monitoring of VE from the exhaust of each control 
device, with those two VE monitoring events at least 4 hours apart. If 
VE are observed, then the owner or operator would need to take 
corrective action within 1 hour, including isolating, shutting down, 
and conducting internal inspections of any baghouse compartment 
associated with VE indicating abnormal operations and fixing the 
compartment before it is put back in service.
3. What key comments did we receive regarding control device monitoring 
requirements and what are our responses?
    Comment: Several commenters stated that the proposed rule requires 
either the installation of PM CEMS or the installation of BLDS on stack 
emission points associated with fabric filter (baghouse) control 
systems for demonstration of continuous compliance with the PM limit. 
The commenters stated that the EPA has not considered the large number 
of stacks involved and the complexity, time, and cost for installing 
BLDS or PM CEMS monitoring systems on the baghouses of potline primary 
control systems.
    The commenters stated that there are significant and substantial 
issues with this requirement that merit rethinking.

[[Page 62409]]

The commenters stated that there is already a requirement in the 40 CFR 
part 63, subpart LL rule for a daily visual check for opacity on all 
stacks associated with baghouse control systems. The commenters stated 
that this serves the same function and purpose as the installation of 
BLDSs and has been working well in that manner since the time the 
original rules were finalized in 1997.
    The commenters stated that the EPA concluded ``. . . that all 
existing prebake potlines will be able to meet these MACT floor limits 
for PM without the need to install additional controls because the 
performance of all sources in the category is similar, all of the 
potlines within each of the subcategories utilize very similar emission 
control technology, the average emissions from each source are well 
below the MACT floor limit and emissions data from every facility that 
performed emissions testing were included in the dataset used to 
develop the MACT floor.'' The commenters stated that it is clear that 
the daily VE inspection, corrective action, and baghouse maintenance 
practices that facilities have already implemented in response to the 
enhanced monitoring requirements of current 40 CFR part 63, subpart LL 
are resulting in a level of baghouse performance that ensures ongoing 
continuous compliance with the proposed PM emission limits.
    The commenters stated that the EPA notes in the proposed rule that 
potline secondary PM emissions comprise by far the largest share of 
primary aluminum reduction plant PM emissions, and these would not be 
addressed with BLDS. The commenters cited test data to highlight this 
issue and stated that the EPA's own analysis of control options on 
secondary PM emissions from potlines found them to not be economically 
feasible yet the resulting risks are still within acceptable risk 
limits.
    The commenters stated that the most common potline primary PM 
control system, the A-398 scrubber system, has multiple stacks 
associated with each control device, and there are multiple control 
devices for each potline. The commenters stated that a survey of U.S. 
primary aluminum facilities indicated that at present there are 388 
potline stack emission points across seven operating plants that would 
need to install BLDS in response to this proposed new requirement. The 
commenters stated that there are 50 to 100 individual stacks per 
potline at some of their facilities and provided a table of the 
affected sources. The commenters stated that the costs, complexity, and 
time required for installing BLDS or PM CEMS at a facility with over 
100 potline control device stacks are formidable.
    The commenters provided a cost analysis of installation and 
operating cost for BLDS and estimated that industry-wide, this would 
result in cumulative $5.24 million of initial costs and $1.2 million of 
annual costs to comply with this requirement for potlines, not 
including the additional costs relative to compliance for anode bake 
furnaces and paste production plants. The commenters stated that none 
of these very significant costs are included in either the December 
2014 supplemental proposal preamble discussion of the costs/benefit 
calculation or the Revised Draft Cost Impacts for the Primary Aluminum 
Source Category document dated November 13, 2014. The commenters stated 
that inclusion of these bag leak detector costs alters the cost/benefit 
dynamic substantially such that it changes the calculation from a 
slight net benefit to a significant net cost. The commenters stated 
that the bag leak detector option is the most cost-effective of the two 
compliance options presented in the proposed rule (BLDS versus PM 
CEMS). The commenters urged the EPA to recalculate the revised cost 
estimate to address the installation of BLDS or PM CEMS on existing 
sources and to provide for the opportunity to comment on the changes.
    The commenters stated that the proposed requirements of 40 CFR 
63.848(o)(3)(i) require initiation of procedures to determine the cause 
of a BLDS alarm with 30 minutes. The commenters stated that the subpart 
LL requirements of 40 CFR 63.848(h) all require the initiation of 
corrective action within 1 hour. The commenters stated that the EPA 
should set the time frame for initiating a response to BLD events at 1 
hour so as to be consistent with the other corrective action 
requirements.
    The commenters stated that the proposed timelines for compliance do 
not consider the time required to design, procure, and install and 
operate a BLDS or PM CEMS on each baghouse stack. The commenters stated 
that since the proposed requirement to install BLDS or PM CEMS on 
potline control devices is unnecessary and cost-prohibitive for 
existing potlines, they strongly recommend that BLDS and PM CEMS 
provisions be deleted from the final rule requirements in their 
entirety.
    The commenters stated that the EPA's proposed requirements of 40 
CFR 63.848(o)(1) pertain to baghouse preventative maintenance 
requirements. The commenters stated that facilities already have to 
comply with similar requirements for proper operation and maintenance 
of emission control equipment under state or federal requirements as 
included in their title V air operating permits. The commenters stated 
that the EPA should tailor the proposed requirements to specifically 
address the development and implementation of procedures pertaining to 
the BLDS.
    The commenters recommended (in the event that BLDS is in the final 
rule) revisions to 40 CFR 63.848(o)(1) and (3)(i).
    Response: The EPA agrees that installation of BLDS or PM CEMS for 
certain existing emission control configurations would be both 
technically challenging and cost prohibitive for some facilities due to 
the large number of individual stacks supporting these control devices. 
We also agree with the commenters that PM emissions from potlines are 
dominated by secondary roof vent emissions. This is a result of 
effective emissions control on the primary stacks and the difficulty 
(technical and economic) associated with installation and operation of 
secondary roof vent emission controls. Moreover, we further find that 
under these circumstances, enhanced VE monitoring provides sufficiently 
reliable and timely information for determining compliance with the PM 
standards--in particular, the twice daily VE monitoring with 
requirement for initiation of corrective actions (if applicable), 
including isolation and internal inspection of a scrubber compartment, 
within 1 hour.\14\ Therefore, we are providing owners or operators of 
existing affected sources the options to monitor these sources with 
either BLDS, PM CEMS, or enhanced VE observations, as described above. 
Further, for those sources that do have BLDS, we agree that 1 hour is 
the appropriate length of time for initiation of root cause analysis 
for alarms and, therefore, are promulgating this requirement.
---------------------------------------------------------------------------

    \14\ See Sierra Club v. EPA, 353 F. 3d 976, 991 (D.C. Cir. 2004) 
(per Roberts, J.) (enhanced monitoring requirement in CAA section 
114(a)(3) does not mandate continuous monitoring or create a 
presumption for such monitoring. Consistent with that reading, CAA 
section 504 (b) provides that ``continuous emissions monitoring need 
not be required if alternative methods are available that provide 
sufficiently reliable and timely information for determining 
compliance'').
---------------------------------------------------------------------------

4. What is the rationale for our final approach regarding control 
device monitoring requirements?
    The final rule will require annual PM testing of the primary 
control device and continuous or frequent monitoring

[[Page 62410]]

with BLDS, PM CEMS, or VE observations. The EPA believes it is 
necessary that facilities conduct at least one of these monitoring 
measures to ensure that the primary control device is maintained in 
good working order throughout the year. As mentioned above, as an 
alternative to BLDS or PM CEMS, we are finalizing a third option of 
twice daily visual inspections of each exhaust stack(s) of each control 
device using Method 22 (at least 4 hours apart) for existing sources. 
Existing sources will have the option to perform Method 22 inspections, 
install BLDS, or install PM CEMS. We believe that the twice daily 
visual inspection alternative will provide adequate assurance that the 
control devices are properly operated and maintained.
    We believe that future potline air pollution control systems will 
be constructed/installed with a newer technology (dry injection type), 
rather than the currently installed (older) technology A-398 type. The 
newer technologies have significantly fewer stack emission points than 
the many stacks of the A-398 systems. Consequently, the number of BLDS 
needed would be substantially less with those systems than for the A-
398 systems. For this reason, we are maintaining the requirement to 
install BLDS or PM CEMS on new sources.

E. What changes did we make to compliance dates for the Primary 
Aluminum Production source category?

1. What existing source compliance dates did we propose for the Primary 
Aluminum Production source category?
    The proposed compliance dates for existing sources in the December 
2014 supplemental proposal were as follows:
     Date of publication of final rule for the malfunction 
provisions and the electronic reporting provisions;
     One year after date of publication of final rule for 
potlines subject to the COS and PM emission limits; prebake potlines 
subject to POM emission limits; the potline, paste production plant, 
and anode bake furnace work practices; anode bake furnaces and paste 
production plants subject to PM emission limits; and pitch storage 
tanks subject to POM standards; and
     Two years after date of publication of final rule for 
Soderberg potlines subject to the POM, Ni, and As emission limits.
2. What changes is EPA making to the proposed existing source 
compliance dates for the Primary Aluminum Production source category?
    The EPA has revised the compliance dates for existing sources in 
the Primary Aluminum Production source category from those proposed in 
2014 as follows:
     The compliance date was changed from 1 year after date of 
publication of final rule to 2 years after date of publication of final 
rule for prebake potlines subject to POM and PM emission limits and for 
pitch storage tanks subject to POM equipment standards;
     The compliance date of 1 year after date of publication of 
final rule was added for Soderberg potlines subject to PCB emission 
limits; and
     The compliance date of 2 years after date of publication 
of final rule was added for anode bake furnaces subject to Hg emission 
limits.
    For more discussion of the promulgated compliance dates, refer to 
the document, Final Rationale for Selection of Compliance Dates for the 
Primary Aluminum Production Source Category, which is available in the 
docket for this action (Docket ID No. EPA-HQ-OAR-2011-0797).
3. What key comments did we receive regarding compliance dates and what 
are our responses?
    Comment: Several commenters stated concern with the compliance 
dates outlined in the supplemental proposal. The commenters stated that 
the compliance dates in the December 2014 proposal are in marked 
contrast to the 2011 proposal that included a 3-year compliance window 
for all changes. The commenters stated that they are concerned that the 
rationale used to dramatically shorten the compliance timelines is not 
reflective of actual on-site conditions and decision-making/approval 
processes for the changes required for compliance. The commenters 
stated that new emission limits imposed on the affected facilities will 
require installation of additional emission controls and/or monitoring 
devices.
    The commenters stated that at least one facility will be required 
to install a Method 14 manifold or Method 14A cassette system in a 
currently operating potline for collecting roof monitor samples to 
determine emissions of PM and POM. The commenters stated that a number 
of facilities currently do not have an emission control system on their 
existing pitch storage tanks. The commenters stated that these 
facilities will be required to install and test (or certify) an 
emission control system to meet the 95-percent POM reduction 
requirement.
    The commenters stated that the effort involved in the determination 
of the exact changes that will be needed; the selection, installation, 
and startup of new controls and their associated equipment; and 
consideration of the business planning cycle for making significant new 
capital and operating expense monetary outlays all indicate that more 
than 1 year is needed to have the emissions control and monitoring 
devices installed and properly operational.
    The commenters requested an increased amount of time for compliance 
dates for malfunction and ERT provisions, work practices, and emission 
limits.
    Response: The EPA has received information from Alcoa that their 
Wenatchee facility currently has two potlines (potlines 2 and 3) that 
are not equipped with a Method 14 manifold or Method 14A cassette 
system. Either a manifold or cassette system is required to monitor 
secondary potline emissions and to demonstrate compliance with the 
potline PM and POM emission limits. Alcoa provided cost estimates for 
the installation of a Method 14 manifold and a Method 14A cassette 
system. These costs were estimated at $500,000 (or approximately 
$55,000 per year annualized) for either system (see Installation of 
Method 14 or 14A Sampling Equipment at Alcoa Wenatchee, Docket item 
number EPA-HQ-OAR-2011-0797-0385). After considering this comment and 
after further evaluation, we agree that a compliance date of 2 years 
after publication of the final rule is appropriate for the 
demonstration of compliance with the potline emissions limits because 
some facilities may need to install Method 14 manifolds or Method 14A 
cassette systems to demonstrate compliance, and we believe that up to 2 
years may be needed to plan, design, construct, and install such 
systems and complete the required testing and analyses.
    After further evaluation, the EPA determined that the appropriate 
compliance date for the 95-percent POM reduction requirement for pitch 
storage tanks is 2 years from the publication date of the final rule. 
The EPA agrees with the commenters that this additional time may be 
needed to install, test, and certify emission control systems.
    We are finalizing the proposed compliance dates for existing 
sources for the malfunction provisions and the electronic reporting 
provisions.
    We are finalizing a compliance date of 1 year after date of 
publication of the final rule for potlines subject to the work practice 
standards and the COS emission limits, and for anode bake furnaces and 
paste production plants

[[Page 62411]]

subject to work practices and PM emission limits.
    We are finalizing a compliance date of 2 years after date of 
publication of the final rule for prebake potlines subject to POM 
emission limits; for Soderberg potlines subject to revised POM emission 
limits and emission limits for Ni, As, and PCB; for potlines subject to 
PM emissions limits; and for existing pitch storage tank POM equipment 
standards.
    We are finalizing a compliance date of 2 years after date of 
publication of final rule for anode bake furnaces subject to Hg 
emission limits.
4. What is the rationale for our final approach regarding compliance 
dates?
    The EPA extended the compliance dates for prebake potlines subject 
to POM and PM emissions limits from 1 to 2 years after date of 
publication of the final rule to give owners or operators an 
appropriate amount of time to install the manifolds or cassette systems 
necessary to sample the potline fugitive emissions. Monitoring of 
potline fugitive emissions will be required in order to demonstrate 
compliance with the promulgated POM and PM emissions limits unless the 
owner or operator can demonstrate potline similarity for purposes of 
these HAP pursuant to 40 CFR 63.848(d) of subpart LL, and the EPA finds 
that the 2 year compliance time allows adequate time for owners or 
operators to apply for similarity determinations.
    Similarly, the compliance date for existing pitch storage tanks 
subject to POM equipment standards was extended by EPA from 1 to 2 
years after date of publication of the final rule to give owners or 
operators an appropriate amount of time to install, test, and certify 
the emission control systems.
    The compliance date of 1 year after date of publication of the 
final rule was added for Soderberg potlines subject to a PCB emission 
limit or D/F work practice standards. We believe that 1 year will be 
sufficient to demonstrate compliance with these requirements for 
existing Soderberg potlines, in the unlikely event that the existing 
Soderberg potlines are restarted, since the available data suggests 
that no modifications or additional controls are necessary to meet that 
limit.
    The EPA added a compliance date of 2 years after date of 
publication of the final rule for anode bake furnaces subject to the Hg 
emission limit. We believe 2 years is justified in this case to provide 
industry sufficient time to schedule and perform testing and take 
appropriate subsequent steps to ensure compliance.

V. Summary of Cost, Environmental, and Economic Impacts and Additional 
Analyses Conducted

A. What are the affected sources?

    The affected sources are new and existing potlines, new and 
existing pitch storage tanks, new and existing anode bake furnaces 
(except for one that is located at a facility that only produces anodes 
for use off-site and is subject to the state MACT determination 
established by the regulatory authority), and new and existing paste 
production plants.

B. What are the air quality impacts?

    We estimate that the promulgated lower VSS2 potline POM emissions 
limit would reduce POM emissions from the one Soderberg facility by 
approximately 53 tpy if the facility were to resume operation. 
Furthermore, we estimate that these standards would also result in 
about 1 tpy reduction of HAP metals and 40 tpy reduction of PM with 
diameter of 2.5 microns and less (PM2.5) if the one 
Soderberg facility reopened. We consider this very unlikely as the 
owner of that facility, Columbia Falls Aluminum Company, has publicly 
announced its permanent closure. However, we include this analysis 
because the potlines have not been demolished yet.
    Finally, we estimate that the addition of controls to the eight 
existing uncontrolled pitch storage tanks located at prebake facilities 
would reduce POM emissions by 1.55 tpy.

C. What are the cost impacts?

    Under the final amendments, facilities are subject to additional 
testing, monitoring, and equipment costs. Owners and operators are 
required to conduct semiannual tests for PM and POM emissions from 
potline roof vents, annual tests for PM and POM from potline primary 
emissions, annual tests of PM and Hg from anode bake furnace exhausts, 
and annual tests of PM from paste production plant exhausts. These 
testing costs are offset by reduced frequency of secondary potline TF 
emissions testing (from monthly to semiannual). In addition, all 
emission stacks not equipped with either BLDS or PM CEMS are subject to 
increased frequency (from daily to twice daily) VE testing. Additional 
monitoring to demonstrate continuous compliance with PM standards for 
anode bake furnaces and paste production plants is required by the 
rule. Eight owners or operators of facilities operating uncontrolled 
pitch storage tanks are required to install and operate controls on 
these tanks, and the owner or operator of one facility with two 
potlines (one idle and one in operation) not currently equipped with 
either a manifold or a cassette system may be required to install this 
equipment. These amendments result in a net estimated reduction in 
testing costs of $1.05 million, a net estimated increase in monitoring 
costs of $625,000, and a net increase in estimated annualized capital 
equipment costs of $260,000. Nationwide annual costs to industry are 
expected to decrease by an estimated $165,000 per year under these 
amendments.
    The memorandum, Final Cost Impacts for the Primary Aluminum 
Production Source Category, includes a description of the details and 
assumptions used for this analysis and is available in the docket for 
this action (Docket ID No. EPA-HQ-OAR-2011-0797).

D. What are the economic impacts?

    We performed an economic impact analysis for the modifications in 
this action. That analysis estimates a net savings for each primary 
aluminum reduction facility based on the belief that the Columbia Falls 
Soderberg facility will not reopen. In March of 2015, the Columbia 
Falls Aluminum Company announced the permanent closure of their 
Soderberg facility. For more information, please refer to the Economic 
Impact Analysis for National Emissions Standards for Hazardous Air 
Pollutants: Primary Aluminum Reduction Plants and Final Economic Impact 
Analysis for the Primary Aluminum Production Source Category documents, 
which are available in the docket for this rulemaking.

E. What are the benefits?

    If the Columbia Falls Soderberg facility were to resume operations, 
there would be an estimated reduction in its annual HAP emissions 
(i.e., about 53 tons) that would provide significant benefits to public 
health. In addition to the HAP reductions, which would ensure an ample 
margin of safety, we also estimate that this final rule would achieve 
about 230 tons of reductions in PM (including 40 tons of 
PM2.5) emissions as a co-benefit of the HAP reductions 
annually (again assuming resumption of plant operation).
    Further, we estimate that the addition of controls to the eight 
existing uncontrolled pitch storage tanks at prebake facilities would 
reduce POM emissions by 1.55 tpy.
    This rulemaking is not an ``economically significant regulatory 
action'' under Executive Order 12866 because it is not likely to have 
an annual effect on the economy of $100

[[Page 62412]]

million or more. Therefore, we have not conducted a Regulatory Impact 
Analysis (RIA) for this rulemaking or a benefits analysis. While we 
expect that these avoided emissions will improve air quality and reduce 
health effects associated with exposure to air pollution associated 
with these emissions, we have not quantified or monetized the benefits 
of reducing these emissions for this rulemaking. This does not imply 
that there are no benefits associated with these emission reductions. 
We provide a qualitative description of benefits associated with 
reducing these pollutants below. When determining whether the benefits 
of an action exceed its costs, Executive Orders 12866 and 13563 direct 
the Agency to consider qualitative benefits that are difficult to 
quantify, but nevertheless essential to consider.
    Directly emitted particles are precursors to secondary formation of 
PM2.5. Controls installed to reduce HAP would also reduce 
ambient concentrations of PM2.5 as a co-benefit. 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).\15\ When adequate data and resources are available and an RIA is 
required, the EPA generally quantifies several health effects 
associated with exposure to PM2.5 (e.g., U.S. EPA, 
2012).\16\ These 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. PM2.5 also increases light extinction, 
which is an important aspect of visibility.
---------------------------------------------------------------------------

    \15\ 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 http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=216546.
    \16\ 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 Triangle Park, NC. Available on the Internet 
at http://www.epa.gov/ttn/ecas/regdata/RIAs/finalria.pdf.http://www.epa.gov/ttnecas1/regdata/RIAs/PMRIACombinedFile_Bookmarked.pdf.
---------------------------------------------------------------------------

    The rulemaking may prevent increases in emissions of other HAP, 
including HAP metals (As, cadmium, chromium (both total and 
hexavalent), lead, manganese, Hg, and Ni) and PAH. Some of these HAP 
are carcinogenic (e.g., As, PAH), and some have effects other than 
cancer (e.g., kidney disease from cadmium, respiratory and 
immunological effects from Ni). While we cannot quantitatively estimate 
the benefits achieved by reducing emissions of these HAP, we expect 
benefits by reducing exposures to these HAP. More information about the 
health effects of these HAP can be found on the IRIS,\17\ U.S. Agency 
for Toxic Substances and Disease Registry (ATSDR),\18\ and California 
EPA \19\ Web sites.
---------------------------------------------------------------------------

    \17\ U.S. EPA, 2006. Integrated Risk Information System. http://www.epa.gov/iris/index.html.
    \18\ ATSDR, 2013. Minimum Risk Levels (MRLs) for Hazardous 
Substances. http://www.atsdr.cdc.gov/mrls/index.html.
    \19\ California Office of Environmental Health Hazard 
Assessment. Chronic Reference Exposure Levels Adopted by OEHHA as of 
December 2008. http://www.oehha.ca.gov/air/chronic_rels.
---------------------------------------------------------------------------

F. What analysis of environmental justice did we conduct?

    To examine the potential for any EJ issues that might be associated 
with the Primary Aluminum Production source category, we performed a 
demographic analysis, which is an assessment of risks to individual 
demographic groups, of the population close to the facilities. In this 
analysis, we evaluated the distribution of HAP-related cancer risks and 
non-cancer hazards from this source category across different social, 
demographic, and economic groups within the populations living near 
facilities identified as having the highest risks. The results of the 
demographic analysis are summarized in Table 6 in section IV.A.3 of 
this preamble and indicate that there are no significant 
disproportionate risks to any particular minority, low income, or 
indigenous population (see the discussion in section IV.A.3 of this 
preamble). The methodology and the results of the demographic analyses 
are included in a technical report, Analysis of Socio-Economic Factors 
for Populations Living Near Primary Aluminum Facilities, which is 
available in the docket for this rulemaking (docket item No. EPA-HQ-
OAR-2011-0797-0360).

G. What analysis of children's environmental health did we conduct?

    This action is not subject to Executive Order 13045 (62 FR 19885, 
April 23, 1997) because the Agency does not believe the environmental 
health risks or safety risks addressed by this action present a 
disproportionate risk to children. The report, Analysis of Socio-
Economic Factors for Populations Living Near Primary Aluminum 
Facilities, which is available in the docket for this rulemaking, 
indicates that the percentages for all demographic groups exposed to 
various risk levels, including children, are similar to their 
respective nationwide percentages. That report further shows that, 
prior to the implementation of the provisions included in this final 
rule, on a nationwide basis, there are approximately 900,000 people 
exposed to a cancer risk at or above 1-in-1 million and no people 
exposed to a chronic non-cancer TOSHI greater than 1 due to emissions 
from the source category.

VI. Statutory and Executive Order Reviews

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

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

    This action is not a significant regulatory action and was, 
therefore, not submitted to the Office of Management and Budget (OMB) 
for review.

B. Paperwork Reduction Act (PRA)

    The information collection activities in this rule have been 
submitted for approval to the OMB under the PRA. The ICR document 
prepared by the EPA has been assigned EPA ICR number 2447.01. You can 
find a copy of the ICR in the docket for this rule (Docket ID No. EPA-
HQ-OAR-2011-0797) and it is briefly summarized below. The information 
collection requirements are not enforceable until OMB approves them.
    We are finalizing changes to the paperwork requirements for the 
Primary Aluminum Production source category facilities subject to 40 
CFR part 63, subpart LL. In this final rule, we are promulgating less 
frequent testing of TF emissions from potlines. In addition, we are 
removing the burden associated with the affirmative defense provisions 
included in the December 2011 proposal.

[[Page 62413]]

    We estimate 11 regulated entities are currently subject to CFR part 
63, subpart LL and will be subject to this action. The annual 
monitoring, reporting, and recordkeeping burden for this collection 
(averaged over the first 3 years after the effective date of the 
standards) as a result of the final amendments to 40 CFR part 63, 
subpart LL (NESHAP for Primary Aluminum Reduction Plants) is estimated 
to be -$931,000 per year.
    This includes 361 labor hours per year at a total labor cost of 
$27,400 per year, and total non-labor capital, and operation and 
maintenance costs of -$958,000 per year. This estimate includes 
performance tests, notifications, reporting, and recordkeeping 
associated with the new requirements for primary aluminum reduction 
plant operations. The total burden for the federal government (averaged 
over the first 3 years after the effective date of the standard) is 
estimated to be 181 hours per year at a total labor cost of $8,250 per 
year. Burden is defined at 5 CFR 1320.3(b).
    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. When OMB 
approves this ICR, the Agency will announce that approval in the 
Federal Register and publish a technical amendment to 40 CFR part 9 to 
display the OMB control number for the approved information collection 
activities contained in this final rule.

C. Regulatory Flexibility Act (RFA)

    I certify that this action will not have a significant economic 
impact on a substantial number of small entities under the RFA. This 
action will not impose any requirements on small entities. There are no 
small entities in this regulated industry. For this source category, 
which has the NAICS code 331312, the Small Business Administration 
(SBA) small business size standard is 1,000 employees according to the 
SBA small business standards definitions.

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. This 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. This action does not have substantial direct 
effects on one or more Indian tribes, 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. 
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 
the Residual Risk Assessment for the Primary Aluminum Production Source 
Category in Support of the September 2015 Risk and Technology Review 
Final Rule, which is available in the docket for this action (Docket ID 
No. EPA-HQ-OAR-2011-0797).

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 final action involves technical standards. The rule requires 
the use of either ASTM D4239-14e1, ``Standard Test Method for Sulfur in 
the Analysis Sample of Coal and Coke Using High-Temperature Tube 
Furnace Combustion,'' approved March 1, 2014, or ASTM D6376-10, ``Test 
Method for Determination of Trace Metals in Petroleum Coke by 
Wavelength Dispersive X-ray Fluorescence Spectroscopy,'' approved July 
1, 2010. ASTM D4239-14e1, approved March 1, 2014, covers the 
determination of sulfur in samples of coal or coke by high temperature 
tube furnace combustion. ASTM D6376-10, approved July 1, 2010, covers 
the x-ray fluorescence spectrometric determination of total sulfur and 
trace metals in samples of raw or calcined petroleum coke. These are 
voluntary consensus methods. These methods can be obtained from the 
American Society for Testing and Materials, 100 Bar Harbor Drive, West 
Conshohocken, Pennsylvania 19428 (telephone number (610) 832-9500). 
These methods were promulgated in the final rule because they are 
commonly used by primary aluminum reduction plants to demonstrate 
compliance with sulfur dioxide emission limitations imposed in their 
current title V permits.
    This final rule also requires use of Method 428, ``Determination of 
Polychlorinated Dibenzo-P-Dioxin (PCDD), Polychlorinated Dibenzofuran 
(PCDF), and Polychlorinated Biphenyle Emissions (PCB) from Stationary 
Sources,'' amended September 12, 1990. Method 428, amended September 
12, 1990, covers the determination of PCDD, PCDF, or PCB from 
stationary sources. The standard is available from the California Air 
Resources Board, 1001 ``I'' Street, Sacramento, CA 95812 (telephone 
number (800) 242-4450) or at their Web site, http://www.arb.ca.gov/testmeth/vol3/m_428.pdf.
    The EPA has decided to use EPA Method 29 for the determination of 
the concentration of Hg. While the EPA identified ASTM D6784-02 (2008), 
``Standard Test Method for Elemental, Oxidized, Particle-Bound and 
Total Mercury in Flue Gas Generated from Coal-Fired Stationary Sources 
(Ontario Hydro Method),'' ASTM International, West Conshohocken, PA, 
2008, as being potentially applicable, the Agency decided not to use 
it. The use of this voluntary consensus standard would be more 
expensive and is inconsistent with the final Hg standard that was 
determined using EPA Method 29 data.
    Under 40 CFR 63.7(f) and 40 CFR 63.8(f) of Subpart A of the General 
Provisions, a source may apply to the EPA for permission to use 
alternative test methods or alternative monitoring requirements in 
place of any required testing methods, performance specifications, or 
procedures in this final rule.

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

    The EPA believes the human health or environmental risk addressed 
by this

[[Page 62414]]

action will not have potential disproportionately high and adverse 
human health or environmental effects on minority, low-income, or 
indigenous populations because it increases the level of environmental 
protection for all affected populations without having any 
disproportionately high and adverse human health or environmental 
effects on any population, including any minority, low-income or 
indigenous populations. For the Primary Aluminum Production source 
category, the EPA determined that the current health risks posed to 
anyone by actual emissions from this source category are within the 
acceptable range, and that this action will not appreciably reduce 
these risks further.
    These final standards will improve public health and welfare, now 
and in the future, by reducing HAP emissions contributing to 
environmental and human health impacts. These reductions in HAP 
associated with the rule will benefit all populations.
    To examine the potential for any EJ issues that might be associated 
with this source category, we evaluated the distributions of HAP-
related cancer and non-cancer risks across different social, 
demographic, and economic groups within the populations living near the 
facilities where this source category is located. The methods used to 
conduct demographic analyses for this final rule, and the results of 
these analyses, are described in the document, Analysis of Socio-
Economic Factors for Populations Living Near Primary Aluminum 
Facilities, which can be found in the docket for this rulemaking 
(Docket item number EPA-HQ-OAR-2011-0797-0360).
    In the demographics analysis, we focused on populations within 50 
kilometers of the facilities in this source category with emissions 
sources subject to 40 CFR part 63, subpart LL. More specifically, for 
these populations we evaluated exposures to HAP that could result in 
cancer risks of 1-in-one million or greater. We compared the 
percentages of particular demographic groups within the focused 
populations to the total percentages of those demographic groups 
nationwide.

K. Congressional Review Act (CRA)

    This action is subject to the CRA, and the EPA will submit a rule 
report to each House of the Congress and to the Comptroller General of 
the United States. This action is not a ``major rule'' as defined by 5 
U.S.C. 804(2).

List of Subjects in 40 CFR Part 63

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

    Dated: September 10, 2015.
Gina McCarthy,
Administrator.

    For the reasons stated in the preamble, Title 40, chapter I, of the 
Code of Federal Regulations (CFR) is amended as follows:

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

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

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

Subpart A--General Provisions

0
2. Section 63.14 is amended:
0
a. By redesignating paragraphs (b)(1) and (2) as paragraphs (b)(2) and 
(3), respectively, and adding new paragraph (b)(1);
0
b. By redesignating paragraphs (h)(77) through (95) as paragraphs 
(h)(80) through (98), respectively;
0
c. By redesignating paragraphs (h)(53) through (76) as paragraphs 
(h)(55) through (78), respectively;
0
d. By redesignating paragraphs (h)(33) through (52) as paragraphs 
(h)(34) through (53), respectively;
0
e. By adding new paragraphs (h)(33), (54) and (79); and
0
f. By redesignating paragraphs (k)(1) through (4) as paragraphs (k)(2) 
through (5), respectively, and adding new paragraph (k)(1).
    The additions read as follows:

Sec.  63.14  Incorporations by reference.

* * * * *
    (b) * * *
    (1) Industrial Ventilation: A Manual of Recommended Practice, 22nd 
Edition, 1995, Chapter 3, ``Local Exhaust Hoods'' and Chapter 5, 
``Exhaust System Design Procedure.'' IBR approved for Sec. Sec.  
63.843(b) and 63.844(b).
* * * * *
    (h) * * *
    (33) ASTM D2986-95A, ``Standard Practice for Evaluation of Air 
Assay Media by the Monodisperse DOP (Dioctyl Phthalate) Smoke Test,'' 
approved September 10, 1995, IBR approved for section 7.1.1 of Method 
315 in appendix A to this part.
* * * * *
    (54) ASTM D4239-14e1, ``Standard Test Method for Sulfur in the 
Analysis Sample of Coal and Coke Using High-Temperature Tube Furnace 
Combustion,'' approved March 1, 2014, IBR approved for Sec.  63.849(f).
* * * * *
    (79) ASTM D6376-10, ``Standard Test Method for Determination of 
Trace Metals in Petroleum Coke by Wavelength Dispersive X-Ray 
Fluorescence Spectroscopy,'' Approved July 1, 2010, IBR approved for 
Sec.  63.849(f).
* * * * *
    (k) * * *
    (1) Method 428, ``Determination Of Polychlorinated Dibenzo-P-Dioxin 
(PCDD), Polychlorinated Dibenzofuran (PCDF), and Polychlorinated 
Biphenyle Emissions from Stationary Sources,'' amended September 12, 
1990, IBR approved for Sec.  63.849(a)(13) and (14).
* * * * *

Subpart LL--National Emission Standards for Hazardous Air 
Pollutants for Primary Aluminum Reduction Plants

0
3. Section 63.840 is amended by revising paragraph (a) to read as 
follows:

Sec.  63.840  Applicability.

    (a) Except as provided in paragraph (b) of this section, the 
requirements of this subpart apply to the owner or operator of each new 
or existing pitch storage tank, potline, paste production plant and 
anode bake furnace associated with primary aluminum production and 
located at a major source as defined in Sec.  63.2.
* * * * *

Sec.  63.841  [Removed and reserved]

0
4. Section 63.841 is removed and reserved.

0
5. Section 63.842 is amended by:
0
a. Adding, in alphabetical order, a definition of ``High purity 
aluminum'';
0
b. Removing the definition for ``Horizontal stud Soderberg (HSS) 
process'';
0
c. Adding, in alphabetical order, definitions of ``Operating day'' and 
``Particulate matter (PM)'';
0
d. Revising the definition for ``Paste production plant'';
0
e. Adding, in alphabetical order definitions of ``Polychlorinated 
biphenyl (PCB)'', ``Startup of an anode bake furnace'', and ``Toxicity 
equivalence (TEQ)''; and
0
f. Removing the definition for ``Vertical stud Soderberg one 
(VSS1)''.The revisions and additions read as follows:

Sec.  63.842  Definitions.

* * * * *

[[Page 62415]]

    High purity aluminum means aluminum produced with an average purity 
level of at least 99.9 percent.
* * * * *
    Operating day means a 24-hour period between 12 midnight and the 
following midnight during which an affected source operates at any 
time. It is not necessary for operations to occur for the entire 24-
hour period.
    Particulate matter (PM) means, for the purposes of this subpart, 
emissions of particulate matter that serve as a measure of total 
particulate emissions and as a surrogate for metal hazardous air 
pollutants contained in the particulates, including but not limited to: 
Antimony, arsenic, beryllium, cadmium, chromium, cobalt, lead, 
manganese, nickel and selenium.
    Paste production plant means the processes whereby calcined 
petroleum coke, coal tar pitch (hard or liquid) and/or other materials 
are mixed, transferred and formed into briquettes or paste for vertical 
stud Soderberg (VSS) processes or into green anodes for a prebake 
process. This definition includes all operations from initial mixing to 
final forming (i.e., briquettes, paste, green anodes) within the paste 
production plant, including conveyors and units managing heated liquid 
pitch.
* * * * *
    Polychlorinated biphenyl (PCB) means any or all of the 209 possible 
chlorinated biphenyl isomers.
* * * * *
    Startup of an anode bake furnace means the process of initiating 
heating to the anode bake furnace. The startup or re-start of the 
furnace begins when the heating begins. The startup or re-start 
concludes at the start of the second anode bake cycle if the furnace 
was at ambient temperature upon startup or when the anode bake cycle 
resumes if the furnace was not at ambient temperature.
* * * * *
    Toxicity equivalence (TEQ) means an international method of 
expressing toxicity equivalents for PCBs as defined in U.S. EPA, 
Recommended Toxicity Equivalence Factors (TEFs) for Human Health Risk 
Assessments of 2,3,7,8-Tetrachlorodibenzo-p-dioxin and Dioxin-Like 
Compounds, EPA/100/R-10/005 December 2010.
* * * * *

0
6. Section 63.843 is amended by:
0
a. Revising paragraph (a) introductory text, and paragraphs (a)(1)(iv), 
(a)(1)(vi), and (a)(2)(iii);
0
b. Removing paragraph (a)(1)(vii);
0
c. Removing and reserving paragraphs (a)(1)(v), (a)(2)(i) and 
(a)(2)(ii);
0
d. Adding paragraphs (a)(2)(iv) through (vii);
0
e. Redesignating paragraph (a)(3) as (a)(7) and adding new paragraphs 
(a)(3) through (6);
0
f. Revising paragraph (b) introductory text, and paragraph (b)(1);
0
g. Adding paragraph (b)(4);
0
h. Revising paragraph (c); and
0
i. Adding paragraphs (d), (e) and (f).
    The revisions and additions read as follows:

Sec.  63.843  Emission limits for existing sources.

    (a) Potlines. The owner or operator shall not discharge or cause to 
be discharged into the atmosphere any emissions of TF, POM, PM, nickel, 
arsenic or PCB in excess of the applicable limits in paragraphs (a)(1) 
through (6) of this section.
    (1) * * *
    (iv) 0.8 kg/Mg (1.6 lb/ton) of aluminum produced for each SWPB 
potline; and
    (v) [Reserved]
    (vi) 1.35 kg/Mg (2.7 lb/ton) of aluminum produced for each VSS2 
potline.
    (2) * * *
    (i) [Reserved]
    (ii) [Reserved]
    (iii) 0.85 kg/Mg (1.9 lb/ton) of aluminum produced for each VSS2 
potline;
    (iv) 0.55 kg/Mg (1.1 lb/ton) of aluminum produced for each CWPB1 
prebake potline;
    (v) 6.0 kg/Mg (12 lb/ton) of aluminum produced for each CWPB2 
prebake potline;
    (vi) 1.4 kg/Mg (2.7 lb/ton) of aluminum produced for each CWPB3 
prebake potline; and
    (vii) 8.5 kg/Mg (17 lb/ton) of aluminum produced for each SWPB 
prebake potline.
    (3) PM limits. Emissions of PM shall not exceed:
    (i) 3.7 kg/Mg (7.4 lb/ton) of aluminum produced for each CWPB1 
potline;
    (ii) 5.5 kg/Mg (11 lb/ton) of aluminum produced for each CWPB2 
potline;
    (iii) 10 kg/Mg (20 lb/ton) of aluminum produced for each CWPB3 
potline;
    (iv) 2.45 kg/Mg (4.9 lb/ton) of aluminum produced for each SWPB 
potline; and
    (v) 13 kg/Mg (26 lb/ton) of aluminum produced for each VSS2 
potline.
    (4) Nickel limit. Emissions of nickel shall not exceed 0.07 lb/ton 
of aluminum produced from each VSS2 potline at a primary aluminum 
reduction plant.
    (5) Arsenic limit. Emissions of arsenic shall not exceed 0.006 lb/
ton of aluminum produced from each VSS2 potline at a primary aluminum 
reduction plant.
    (6) PCB limit. Emissions of PCB shall not exceed 2.0 [mu]g toxicity 
equivalence (TEQ) per ton of aluminum produced from each VSS2 potline 
at a primary aluminum reduction plant.
    (7) * * *
    (b) Paste production plants. The owner or operator shall install, 
operate and maintain equipment to capture and control POM and PM 
emissions from each paste production plant.
    (1) The emission capture system shall be installed and operated to 
meet the generally accepted engineering standards for minimum exhaust 
rates as published by the American Conference of Governmental 
Industrial Hygienists in Chapters 3 and 5 of ``Industrial Ventilation: 
A Handbook of Recommended Practice'' (incorporated by reference; see 
Sec.  63.14); and
* * * * *
    (4) PM limit. Emissions of PM shall not exceed 0.041 kg/Mg (0.082 
lb/ton) of paste.
    (c) Anode bake furnaces. The owner or operator shall not discharge 
or cause to be discharged into the atmosphere any emissions of TF, POM, 
PM or mercury in excess of the limits in paragraphs (c)(1) through (4) 
of this section.
    (1) TF limit. Emissions of TF shall not exceed 0.10 kg/Mg (0.20 lb/
ton) of green anode;
    (2) POM limit. Emissions of POM shall not exceed 0.09 kg/Mg (0.18 
lb/ton) of green anode;
    (3) PM limit. Emissions of PM shall not exceed 0.10 kg/Mg (0.20 lb/
ton) of green anode; and
    (4) Mercury limit. Emissions of mercury shall not exceed 1.7 [mu]g/
dscm.
    (d) Pitch storage tanks. Each pitch storage tank shall be equipped 
with an emission control system designed and operated to reduce inlet 
emissions of POM by 95 percent or greater.
    (e) COS limit. Emissions of COS must not exceed 1.95 kg/Mg (3.9 lb/
ton) of aluminum produced for each potline.
    (f) 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. 
Determination of whether such operation and maintenance procedures are 
being used will be based on information available to the Administrator 
which may include, but is not limited to, monitoring results, review of 
operation and maintenance procedures, review of

[[Page 62416]]

operation and maintenance records and inspection of the source.

0
7. Section 63.844 is amended by:
0
a. Revising paragraph (a) introductory text, and paragraph (a)(2);
0
b. Adding paragraphs (a)(3) through (6);
0
c. Revising paragraph (b);
0
d. Revising paragraph (c); and
0
e. Adding paragraphs (e) and (f).
    The revisions and additions read as follows:

Sec.  63.844  Emission limits for new or reconstructed sources.

    (a) Potlines. The owner or operator shall not discharge or cause to 
be discharged into the atmosphere any emissions of TF, POM, PM, nickel, 
arsenic or PCB in excess of the applicable limits in paragraphs (a)(1) 
through (6) of this section.
* * * * *
    (2) POM limit. Emissions of POM from potlines must not exceed 0.39 
kg/Mg (0.77 lb/ton) of aluminum produced.
    (3) PM limit. Emissions of PM from potlines must not exceed 2.45 
kg/Mg (4.9 lb/ton) of aluminum produced.
    (4) Nickel limit. Emissions of nickel shall not exceed 0.035 kg/Mg 
(0.07 lb/ton) of aluminum produced from each Soderberg potline at a 
primary aluminum reduction plant.
    (5) Arsenic limit. Emissions of arsenic shall not exceed 0.003 kg/
Mg (0.006 lb/ton) of aluminum produced from each Soderberg potline at a 
primary aluminum reduction plant.
    (6) PCB limit. Emissions of PCB shall not exceed 2.0 [micro]g TEQ/
ton of aluminum produced from each Soderberg potline at a primary 
aluminum reduction plant.
    (b) Paste production plants. (1) The owner or operator shall meet 
the requirements in Sec.  63.843(b)(1) through (3) for existing paste 
production plants and shall not discharge or cause to be discharged 
into the atmosphere any emissions of PM in excess of the limit in 
paragraph (b)(2) of this section.
    (2) Emissions of PM shall not exceed 0.0028 kg/Mg (0.0056 lb/ton) 
of green anode.
    (c) Anode bake furnaces. The owner or operator shall not discharge 
or cause to be discharged into the atmosphere any emissions of TF, PM, 
POM or mercury in excess of the limits in paragraphs (c)(1) through (4) 
of this section.
    (1) TF limit. Emissions of TF shall not exceed 0.01 kg/Mg (0.02 lb/
ton) of green anode;
    (2) POM limit. Emissions of POM shall not exceed 0.025 kg/Mg (0.05 
lb/ton) of green anode;
    (3) PM limit. Emissions of PM shall not exceed 0.035 kg/Mg (0.07 
lb/ton) of green anode; and
    (4) Mercury limit. Emissions of mercury shall not exceed 1.7 [mu]g/
dscm.
* * * * *
    (e) COS limit. Emissions of COS must not exceed 1.55 kg/Mg (3.1 lb/
ton) of aluminum produced for each potline.
    (f) 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. 
Determination of whether such operation and maintenance procedures are 
being used will be based on information available to the Administrator 
which may include, but is not limited to, monitoring results, review of 
operation and maintenance procedures, review of operation and 
maintenance records and inspection of the source.

0
8. Section 63.846 is amended by:
0
a. Revising paragraph (b);
0
b. Revising paragraph (c);
0
c. Revising paragraphs (d)(2)(ii) through (iv) and (d)(4)(i) through 
(iii); and
0
d. Removing paragraph (d)(4)(iv).
    The revisions read as follows:

Sec.  63.846  Emission averaging.

* * * * *
    (b) Potlines. The owner or operator may average emissions from 
potlines and demonstrate compliance with the limits in Tables 1 through 
3 of this subpart using the procedures in paragraphs (b)(1) through (3) 
of this section.
    (1) Semiannual average emissions of TF shall not exceed the 
applicable emission limit in Table 1 of this subpart. The emission rate 
shall be calculated based on the total primary and secondary emissions 
from all potlines comprising the averaging group over the period 
divided by the quantity of aluminum produced during the period, from 
all potlines comprising the averaging group. To determine compliance 
with the applicable emission limit in Table 1 of this subpart for TF 
emissions, the owner or operator shall determine the average emissions 
(in lb/ton) from each potline from at least three runs per potline 
semiannually for TF secondary emissions and at least three runs per 
potline primary control system each year using the procedures and 
methods in Sec. Sec.  63.847 and 63.849. The owner or operator shall 
combine the results of secondary TF average emissions with the TF 
results for the primary control system and divide total emissions by 
total aluminum production.
    (2) Semiannual average emissions of POM shall not exceed the 
applicable emission limit in Table 2 of this subpart. The emission rate 
shall be calculated based on the total primary and secondary emissions 
from all potlines comprising the averaging group over the period 
divided by the quantity of aluminum produced during the period, from 
all potlines comprising the averaging group. To determine compliance 
with the applicable emission limit in Table 2 of this subpart for POM 
emissions, the owner or operator shall determine the average emissions 
(in lb/ton) from each potline from at least three runs per potline 
semiannually for POM secondary emissions and at least three runs per 
potline primary control system each year for POM primary emissions 
using the procedures and methods in Sec. Sec.  63.847 and 63.849. The 
owner or operator shall combine the results of secondary POM average 
emissions with the POM results for the primary control system and 
divide total emissions by total aluminum production.
    (3) Semiannual average emissions of PM shall not exceed the 
applicable emission limit in Table 3 of this subpart. The emission rate 
shall be calculated based on the total primary and secondary emissions 
from all potlines comprising the potline group over the period divided 
by the quantity of aluminum produced during the period, from all 
potlines comprising the averaging group. To determine compliance with 
the applicable emission limit in Table 3 of this subpart for PM 
emissions, the owner or operator shall determine the average emissions 
(in lb/ton) from each potline from at least three runs per potline 
semiannually for PM secondary emissions and at least three runs per 
potline primary control system each year for PM primary emissions using 
the procedures and methods in Sec. Sec.  63.847 and 63.849. The owner 
or operator shall combine the results of secondary PM average emissions 
with the PM results for the primary control system and divide total 
emissions by total aluminum production.
    (c) Anode bake furnaces. The owner or operator may average TF 
emissions from anode bake furnaces and demonstrate compliance with the 
limits in Table 4 of this subpart using the procedures in paragraphs 
(c)(1) and (2) of this section. The owner or operator also may average 
POM emissions from anode bake furnaces and demonstrate compliance with 
the limits in Table 4 of this subpart using the procedures in 
paragraphs (c)(1) and (2) of this section. The owner or operator also 
may average

[[Page 62417]]

PM emissions from anode bake furnaces and demonstrate compliance with 
the limits in Table 4 of this subpart using the procedures in 
paragraphs (c)(1) and (2) of this section.
    (1) Annual emissions of TF, POM and/or PM from a given number of 
anode bake furnaces making up each averaging group shall not exceed the 
applicable emission limit in Table 4 of this subpart in any one year; 
and
    (2) To determine compliance with the applicable emission limit in 
Table 4 of this subpart for anode bake furnaces, the owner or operator 
shall determine TF, POM and/or PM emissions from the control device for 
each anode bake furnace at least once each year using the procedures 
and methods in Sec. Sec.  63.847 and 63.849.
    (d) * * *
    (2) * * *
    (ii) The assigned TF, POM and/or PM emission limit for each 
averaging group of potlines and/or anode bake furnaces;
    (iii) The specific control technologies or pollution prevention 
measures to be used for each emission source in the averaging group and 
the date of its installation or application. If the pollution 
prevention measures reduce or eliminate emissions from multiple 
sources, the owner or operator must identify each source;
    (iv) The test plan for the measurement of TF, POM and/or PM 
emissions in accordance with the requirements in Sec.  63.847(b);
* * * * *
    (4) * * *
    (i) Any averaging between emissions of differing pollutants or 
between differing sources. Emission averaging shall not be allowed 
between TF, POM and/or PM, and emission averaging shall not be allowed 
between potlines and anode bake furnaces;
    (ii) The inclusion of any emission source other than an existing 
potline or existing anode bake furnace or the inclusion of any potline 
or anode bake furnace not subject to the same operating permit; or
    (iii) The inclusion of any potline or anode bake furnace while it 
is shut down, in the emission calculations.
* * * * *

0
9. Section 63.847 is amended by:
0
a. Revising paragraph (a) introductory text, and paragraphs (a)(1) and 
(a)(2);
0
b. Removing and reserving paragraph (a)(3);
0
c. Adding paragraphs (a)(5) through (9);
0
d. Removing and reserving paragraph (b)(6);
0
e. Revising paragraph (c) introductory text, paragraph (c)(1), and 
paragraph (c)(2) introductory text;
0
f. Adding paragraph (c)(2)(iv);
0
g. Revising paragraph (c)(3) introductory text;
0
h. Adding paragraphs (c)(3)(iii) and (iv);
0
i. Revising paragraph (d) introductory text and paragraph (d)(1);
0
j. Removing and reserving paragraph (d)(2);
0
k. Revising paragraph (d)(4);
0
l. Adding paragraphs (d)(5) through (7);
0
m. Revising paragraph (e) introductory text, and paragraph (e)(1);
0
n. Removing and reserving paragraph (e)(2);
0
o. Revising paragraphs (e)(3) and (e)(4);
0
p. Adding paragraph (e)(8);
0
q. Revising paragraph (f);
0
r. Revising paragraph (g) introductory text, and paragraphs (g)(2)(ii) 
and (iv);
0
s. Adding and reserving paragraph (i); and
0
t. Adding paragraphs (j), (k), (l) and (m).
    The revisions and additions read as follows:

Sec.  63.847  Compliance provisions.

    (a) Compliance dates. The owner operator of a primary aluminum 
reduction plant must comply with the requirements of this subpart by 
the applicable compliance date in paragraph (a)(1), (a)(2) or (a)(4) of 
this section:
    (1) Except as noted in paragraph (a)(2) of this section, the 
compliance date for an owner or operator of an existing plant or source 
subject to the provisions of this subpart is October 7, 1999.
    (2) The compliance dates for existing plants and sources are:
    (i) October 15, 2015 for the malfunction provisions of Sec.  
63.850(d)(2) and (e)(4)(xvi) and (xvii) and the electronic reporting 
provisions of Sec.  63.850(b), (c) and (f) which became effective 
October 15, 2015.
    (ii) October 17, 2016 for potline work practice standards in Sec.  
63.854 and COS emission limit provisions of Sec.  63.843(e); for anode 
bake furnace startup practices in Sec.  63.847(l) and PM emission 
limits in Sec.  63.843(c)(3); for Soderberg potline PM and PCB emission 
limits in Sec.  63.843(a)(3)(v) and (a)(6); and for paste production 
plant startup practices in Sec.  63.847(m) and PM emission limits in 
Sec.  63.843(b)(4) which became effective October 15, 2015.
    (iii) October 16, 2017 for prebake potline POM emission limits in 
Sec.  63.843(a)(2)(iv) through (vii); for Soderberg potline POM, As and 
Ni emission limits in Sec. Sec.  63.843(a)(2)(iii), (a)(4) and (5); for 
prebake potline PM emission limits in Sec.  63.843(a)(3); for anode 
bake furnace Hg emission limits in Sec.  63.843(c)(4); and for the 
pitch storage tank POM limit provisions of Sec.  63.843(d) which became 
effective October 15, 2015.
    (3) [Reserved]
* * * * *
    (5) Except as provided in paragraphs (a)(6) and (7) of this 
section, a new affected source is one for which construction or 
reconstruction commenced after September 26, 1996.
    (6) For the purposes of compliance with the emission standards for 
PM, a new affected potline, anode bake furnace or paste production 
plant is one for which construction or reconstruction commenced after 
December 8, 2014.
    (7) For the purposes of compliance with the emission standards for 
POM and COS, a new affected prebake potline is one for which 
construction or reconstruction commenced after December 8, 2014.
    (8) For the purposes of compliance with the emission standards for 
As, Ni and POM, a new affected Soderberg potline is one for which 
construction or reconstruction commenced after December 8, 2014.
    (9) For the purposes of compliance with the emission standards for 
Hg, a new affected anode bake furnace is one for which construction or 
reconstruction commenced after December 8, 2014.
* * * * *
    (b) * * *
    (6) [Reserved]
* * * * *
    (c) Following approval of the site-specific test plan, the owner or 
operator must conduct a performance test to demonstrate initial 
compliance according to the procedures in paragraph (d) of this 
section. If a performance test has been conducted on the primary 
control system for potlines, the anode bake furnace, the paste 
production plant, or (if applicable) the pitch storage tank control 
device within the 12 months prior to the compliance date, the results 
of that performance test may be used to demonstrate initial compliance. 
The owner or operator must conduct the performance test:
    (1) During the first month following the compliance date for an 
existing potline (or potroom group), anode bake furnace, paste 
production plant or pitch storage tank.
    (2) By the date determined according to the requirements in 
paragraph (c)(2)(i), (ii), (iii), or (iv) of this section for a new or 
reconstructed potline, anode bake furnace, or pitch storage tank (for 
which the owner or operator

[[Page 62418]]

elects to conduct an initial performance test):
* * * * *
    (iv) By the 30th day following startup of a paste production plant. 
The 30-day period starts when the paste production plant produces green 
anodes.
    (3) By the date determined according to the requirements in 
paragraph (c)(3)(i), (ii), (iii) or (iv) of this section for an 
existing potline, anode bake furnace, paste production plant, or pitch 
storage tank that was shut down at the time compliance would have 
otherwise been required and is subsequently restarted:
* * * * *
    (iii) By the 30th day following startup of a paste production 
plant. The 30-day period starts when the paste production plant 
produces green anodes.
    (iv) By the 30th day following startup for a pitch storage tank. 
The 30-day period starts when the tank is first used to store pitch.
    (d) Performance test requirements. The initial performance test and 
all subsequent performance tests must be conducted in accordance with 
the applicable requirements of the general provisions in subpart A of 
this part, the approved test plan and the procedures in this section. 
Performance tests must be conducted under such conditions as the 
Administrator specifies to the owner or operator based on 
representative performance of the affected source for the period being 
tested. Upon request, the owner or operator must make available to the 
Administrator such records as may be necessary to determine the 
conditions of performance tests.
    (1) TF, POM and PM emissions from potlines. For each potline, the 
owner or operator shall measure and record the emission rates of TF, 
POM and PM exiting the outlet of the primary control system and the 
rate of secondary emissions exiting through each roof monitor, or for a 
plant with roof scrubbers, exiting through the scrubbers. Using the 
equation in paragraph (e)(1) of this section, the owner or operator 
shall compute and record the average of at least three runs 
semiannually for secondary emissions and at least three runs each year 
for the primary control system to determine compliance with the 
applicable emission limit. Compliance is demonstrated when the emission 
rates of TF, POM, and PM are equal to or less than the applicable 
emission limits in Sec.  63.843, Sec.  63.844, or Sec.  63.846.
    (2) [Reserved]
* * * * *
    (4) TF, POM, PM and Hg emissions from anode bake furnaces. For each 
anode bake furnace, the owner or operator shall measure and record the 
emission rate of TF, POM, PM and Hg exiting the exhaust stacks(s) of 
the primary emission control system. In accordance with paragraphs 
(e)(3) and (4) of this section, the owner or operator shall compute and 
record the average of at least three runs each year to determine 
compliance with the applicable emission limits for TF, POM, PM and Hg. 
Compliance is demonstrated when the emission rates of TF, POM, PM and 
Hg are equal to or less than the applicable TF, POM, PM and Hg emission 
limits in Sec.  63.843, Sec.  63.844 or Sec.  63.846.
    (5) Nickel emissions from VSS2 Potlines and new Soderberg potlines. 
(i) For each VSS2 potline, and for each new Soderberg potline, the 
owner or operator must measure and record the emission rate of nickel 
exiting the primary emission control system and the rate of secondary 
emissions of nickel exiting through each roof monitor, or for a plant 
with roof scrubbers, exiting through the scrubbers. Using the equation 
in paragraph (e)(1) of this section, the owner or operator must compute 
and record the average of at least three runs each year for secondary 
emissions and at least three runs each year for primary emissions.
    (ii) Compliance is demonstrated when the emissions of nickel are 
equal to or less than the applicable emission limit in Sec.  
63.843(a)(4) or Sec.  63.844(a)(4).
    (6) Arsenic emissions from VSS2 Potlines and from new Soderberg 
potlines. (i) For each VSS2 potline, and for each new Soderberg 
potline, the owner or operator must measure and record the emission 
rate of arsenic exiting the primary emission control system and the 
rate of secondary emissions of arsenic exiting through each roof 
monitor, or for a plant with roof scrubbers, exiting through the 
scrubbers. Using the equation in paragraph (e)(1) of this section, the 
owner or operator must compute and record the average of at least three 
runs each year for secondary emissions and at least three runs each 
year for primary emissions.
    (ii) Compliance is demonstrated when the emissions of arsenic are 
equal to or less than the applicable emission limit in Sec.  
63.843(a)(5) or Sec.  63.844(a)(5).
    (7) PCB emissions from VSS2 Potlines and from new Soderberg 
potlines. (i) For each VSS2 potline, and for each new Soderberg 
potline, the owner or operator must measure and record the emission 
rate of PCB exiting the primary emission control system and the rate of 
secondary emissions of PCB exiting through each roof monitor, or for a 
plant with roof scrubbers, exiting through the scrubbers. Using the 
equation in paragraph (e)(1) of this section, the owner or operator 
must compute and record the average of at least three runs each year 
for secondary emissions and at least three runs each year for primary 
emissions.
    (ii) Compliance is demonstrated when the emissions of PCB are equal 
to or less than the applicable emission limit in Sec.  63.843(a)(6) or 
Sec.  63.844(a)(6).
    (e) The owner or operator shall determine compliance with the 
applicable TF, POM, PM, nickel, arsenic or PCB emission limits using 
the following equations and procedures:
    (1) Compute the emission rate (Ep) of TF, POM, PM, 
nickel, arsenic or PCB from each potline using Equation 1:
[GRAPHIC] [TIFF OMITTED] TR15OC15.000

Where:

Ep = emission rate of TF, POM, PM, nickel or arsenic from 
a potline, kg/Mg (lb/ton) (or [mu]g TEQ/ton for PCB);
Cs1 = concentration of TF, POM, PM, nickel or arsenic 
from the primary control system, mg/dscm (mg/dscf) (or [mu]g TEQ/
dscf for PCB);
Qsd = volumetric flow rate of effluent gas corresponding 
to the appropriate subscript location, dscm/hr (dscf/hr);
Cs2 = concentration of TF, POM, PM, nickel or arsenic as 
measured for roof monitor emissions, mg/dscm (mg/dscf) (or [mu]g 
TEQ/dscf for PCB);
P = aluminum production rate, Mg/hr (ton/hr);
K = conversion factor, 106 mg/kg (453,600 mg/lb) for TF, 
POM, PM, nickel or arsenic (= 1 for PCB);
1 = subscript for primary control system effluent gas; 
and
2 = subscript for secondary control system or roof 
monitor effluent gas.

    (2) [Reserved]

[[Page 62419]]

    (3) Compute the emission rate (Eb) of TF, POM or PM from 
each anode bake furnace using Equation 2,
[GRAPHIC] [TIFF OMITTED] TR15OC15.001

Where:

Eb = emission rate of TF, POM or PM, kg/mg (lb/ton) of 
green anodes;
Cs = concentration of TF, POM or PM, mg/dscm (mg/dscf);
Qsd = volumetric flow rate of effluent gas, dscm/hr 
(dscf/hr);
Pb = quantity of green anode material placed in the 
furnace, mg/hr (ton/hr); and
K = conversion factor, 10\6\ mg/kg (453,600 mg/lb).

    (4) Compliance with the anode bake furnace Hg emission standard is 
demonstrated if the Hg concentration of the exhaust from the anode bake 
furnace control device is equal to or less than the applicable 
concentration standard in Sec.  63.843(c)(4) or Sec.  63.844(c)(4).
* * * * *
    (8) Compute the emission rate (EPMpp) of PM from each 
paste production plant using Equation 3,
[GRAPHIC] [TIFF OMITTED] TR15OC15.002

Where:

EPMpp = emission rate of PM, kg/mg (lb/ton) of green 
anode material exiting the paste production plant;
Cs = concentration of PM, mg/dscm (mg/dscf);
Qsd = volumetric flow rate of effluent gas, dscm/hr 
(dscf/hr);
Pb = quantity of green anode material exiting the paste 
production plant, mg/hr (ton/hr); and
K = conversion factor, 106 mg/kg (453,600 mg/lb).

    (f) Paste production plants. (1) Initial compliance with the POM 
standards for existing and new paste production plants in Sec. Sec.  
63.843(b) and 63.844(b) will be demonstrated through site inspection(s) 
and review of site records by the applicable regulatory authority.
    (2) For each paste production plant, the owner or operator shall 
measure and record the emission rate of PM exiting the exhaust 
stacks(s) of the primary emission control system. Using the equation in 
paragraph (e)(8) of this section, the owner or operator shall compute 
and record the average of at least three runs each year to determine 
compliance with the applicable emission limits for PM. Compliance with 
the PM standards for existing and new paste production plants is 
demonstrated when the PM emission rates are less than or equal to the 
applicable PM emission limits in Sec. Sec.  63.843(b)(4) and 
63.844(b)(2).
    (g) Pitch storage tanks. The owner or operator must demonstrate 
initial compliance with the standard for pitch storage tanks in 
Sec. Sec.  63.843(d) and 63.844(d) by preparing a design evaluation or 
by conducting a performance test. The owner or operator must submit for 
approval by the regulatory authority the information specified in 
paragraph (g)(1) of this section, along with the information specified 
in paragraph (g)(2) of this section where a design evaluation is 
performed or the information specified in paragraph (g)(3) of this 
section where a performance test is conducted.
* * * * *
    (2) * * *
    (ii) If an enclosed combustion device with a minimum residence time 
of 0.5 seconds and a minimum temperature of 760 degrees C (1,400 
degrees F) is used to meet the emission reduction requirement specified 
in Sec.  63.843(d) and Sec.  63.844(d), documentation that those 
conditions exist is sufficient to meet the requirements of Sec.  
63.843(d) and Sec.  63.844(d);
* * * * *
    (iv) If the pitch storage tank is vented to the emission control 
system installed for control of emissions from the paste production 
plant pursuant to Sec.  63.843(b) or Sec.  63.844(b)(1), documentation 
of compliance with the requirements of Sec.  63.843(b) is sufficient to 
meet the requirements of Sec.  63.843(d) or Sec.  63.844(d);
* * * * *
    (i) [Reserved]
    (j) Carbonyl sulfide (COS) emissions. The owner operator must 
calculate, for each potline, the emission rate of COS for each calendar 
month of operation using Equation 4:
[GRAPHIC] [TIFF OMITTED] TR15OC15.003

Where:

ECOS = the emission rate of COS during the calendar 
month, pounds per ton of aluminum produced;
K = factor accounting for molecular weights and conversion of sulfur 
to carbonyl sulfide = 234;
Y = the mass of anode consumed in the potline during the calendar 
month, tons;
Z = the mass of aluminum produced by the potline during the calendar 
month, tons; and
S = the weighted average fraction of sulfur in the anode coke 
consumed in the production of aluminum during the calendar month 
(e.g., if the weighted average sulfur content of the anode coke 
consumed during the calendar month was 2.5 percent, then S = 0.025). 
The weight of anode coke used during the calendar month of each 
different concentration of sulfur is used to calculate the overall 
weighted average fraction of sulfur.

    Compliance is demonstrated if the calculated value of 
ECOS is less than the applicable standard for COS emissions 
in Sec. Sec.  63.843(e) and 63.844(e).
    (k) Startup of potlines. The owner or operator must develop a 
written startup

[[Page 62420]]

plan as described in Sec.  63.854(b) that contains specific procedures 
to be followed during startup periods of potline(s). Compliance with 
the applicable standards in Sec.  63.854(b) will be demonstrated 
through site inspection(s) and review of site records by the regulatory 
authority.
    (l) Startup of anode bake furnaces. The owner or operator must 
develop a written startup plan as described in paragraphs (l)(1) 
through (4) of this section, to be followed during startup periods of 
bake furnaces. Compliance with the startup plan will be demonstrated 
through site inspection(s) and review of site records by the regulatory 
authority. The written startup plan must contain specific procedures to 
be followed during startup periods of anode bake furnaces, including 
the following:
    (1) A requirement to develop an anode bake furnace startup 
schedule.
    (2) Records of time, date, duration of anode bake furnace startup 
and any nonroutine actions taken during startup of the furnaces.
    (3) A requirement that the associated emission control system be 
operating within normal parametric limits prior to startup of the anode 
bake furnace.
    (4) A requirement to take immediate actions to stop the startup 
process as soon as practicable and continue to comply with Sec.  
63.843(f) or Sec.  63.844(f) if the associated emission control system 
is off line at any time during startup. The anode bake furnace restart 
may resume once the associated emission control system is back on line 
and operating within normal parametric limits.
    (m) Startup of paste production plants. The owner or operator must 
develop a written startup plan as described in paragraphs (m)(1) 
through (3) of this section, to be followed during startup periods for 
paste production plants. Compliance with the startup plan will be 
demonstrated through site inspection(s) and review of site records by 
the regulatory authority. The written startup plan must contain 
specific procedures to be followed during startup periods of paste 
production plants, including the following:
    (1) Records of time, date, duration of paste production plant 
startup and any nonroutine actions taken during startup of the paste 
production plants.
    (2) A requirement that the associated emission control system be 
operating within normal parametric limits prior to startup of the paste 
production plant.
    (3) A requirement to take immediate actions to stop the startup 
process as soon as practicable and continue to comply with Sec.  
63.843(f) or Sec.  63.844(f) if the associated emission control system 
is off line at any time during startup. The paste production plant 
restart may resume once the associated emission control system is back 
on line and operating within normal parametric limits.

0
10. Section 63.848 is amended by:
0
a. Revising paragraphs (a), (b), (c), (d) introductory text, 
(d)(1)(ii), and (d)(7);
0
b. Removing and reserving paragraph (e);
0
c. Adding paragraphs (f)(6) and (7);
0
d. Revising paragraph (g); and
0
e. Adding paragraphs (n), (o) and (p).
    The revisions and additions read as follows:

Sec.  63.848  Emission monitoring requirements.

    (a) TF and PM emissions from potlines. Using the procedures in 
Sec.  63.847 and in the approved test plan, the owner or operator shall 
monitor emissions of TF and PM from each potline by conducting annual 
performance tests on the primary control system and semiannual 
performance tests on the secondary emissions. The owner or operator 
shall compute and record the average semiannually from at least three 
runs for secondary emissions and the average from at least three runs 
for the primary control system to determine compliance with the 
applicable emission limit. The owner or operator must include all valid 
runs in the semiannual average. The duration of each run for secondary 
emissions must represent a complete operating cycle. Potline emissions 
shall be recorded as the sum of the average of at least three runs from 
the primary control system and the average of at least three runs from 
the roof monitor or secondary emissions control device.
    (b) POM emissions from potlines. Using the procedures in Sec.  
63.847 and in the approved test plan, the owner or operator must 
monitor emissions of POM from each potline stack annually and secondary 
potline POM emissions semiannually. The owner or operator must compute 
and record the semiannual average from at least three runs for 
secondary emissions and at least three runs for the primary control 
systems to determine compliance with the applicable emission limit. The 
owner or operator must include all valid runs in the semiannual 
average. The duration of each run for secondary emissions must 
represent a complete operating cycle. The primary control system must 
be sampled over an 8-hour period, unless site-specific factors dictate 
an alternative sampling time subject to the approval of the regulatory 
authority. Potline emissions shall be recorded as the sum of the 
average of at least three runs from the primary control system and the 
average of at least three runs from the roof monitor or secondary 
emissions control device.
    (c) TF, PM, Hg and POM emissions from anode bake furnaces. Using 
the procedures in Sec.  63.847 and in the approved test plan, the owner 
or operator shall determine TF, PM, Hg and POM emissions from each 
anode bake furnace on an annual basis. The owner or operator shall 
compute and record the annual average of TF, PM, Hg and POM emissions 
from at least three runs to determine compliance with the applicable 
emission limits. A minimum of four dscm per run must be collected for 
monitoring of Hg emissions. The owner or operator must include all 
valid runs in the annual average.
    (d) Similar potlines. As an alternative to semiannual monitoring of 
TF, POM or PM secondary emissions from each potline using the methods 
in Sec.  63.849, the owner or operator may perform semiannual 
monitoring of TF, POM or PM secondary emissions from one potline using 
the test methods in Sec.  63.849(a) or (b) to represent the performance 
of similar potline(s). The similar potline(s) must be monitored using 
an alternative method that meets the requirements of paragraphs (d)(1) 
through (7) of this section. Two or more potlines are similar if the 
owner or operator demonstrates that their structure, operability, type 
of emissions, volume of emissions and concentration of emissions are 
substantially equivalent.
    (1) * * *
    (ii) For TF, POM and PM emissions, must meet or exceed Method 14 
criteria.
* * * * *
    (7) If the alternative method is approved by the applicable 
regulatory authority, the owner or operator must perform semiannual 
emission monitoring using the approved alternative monitoring procedure 
to demonstrate compliance with the alternative emission limit for each 
similar potline.
    (e) [Reserved]
    (f) * * *
    (6) For emission sources control device exhaust streams for which 
the owner or operator chooses to demonstrate continuous compliance 
through bag leak detection systems you must install and operate a bag 
leak detection system according to the requirements in paragraph (o) of 
this section, and you must set your operating limit such that the sum 
of the durations of bag leak detection system alarms does not exceed 5 
percent of the process operating time during a 6-month period.

[[Page 62421]]

    (7) For emission sources control device exhaust streams for which 
the owner or operator chooses to demonstrate continuous compliance 
through a PM CEMS, you must install and operate a PM CEMS according to 
the requirements in paragraph (p) of this section. You must determine 
continuous compliance averaged on a rolling 30 operating day basis, 
updated at the end of each new operating day. All valid hours of data 
from 30 successive operating days shall be included in the arithmetic 
average. Compliance is demonstrated when the 30 operating day PM 
emissions are equal to or less than the applicable emission limits in 
Sec.  63.843, Sec.  63.844, or Sec.  63.846.
    (g) The owner or operator of a new or reconstructed affected source 
that is subject to a PM limit shall comply with the requirements of 
either paragraph (f)(6) or (7) of this section. The owner or operator 
of an existing affected source that is equipped with a control device 
and is subject to a PM limit shall:
    (1) Install and operate a bag leak detection system in accordance 
with paragraph (f)(6) of this section; or
    (2) Install and operate a PM CEMS in accordance with paragraph 
(f)(7) of this section; or
    (3) Visually inspect the exhaust stack(s) of each fabric filter 
using Method 22 on a twice daily basis (at least 4 hours apart) for 
evidence of any visible emissions indicating abnormal operations and, 
must initiate corrective actions within 1 hour of a visible emissions 
inspection that indicates abnormal operation. Corrective actions shall 
include, at a minimum, isolating, shutting down and conducting an 
internal inspection of the baghouse compartment that is the source of 
the visible emissions that indicate abnormal operations.
* * * * *
    (n) PM emissions from paste production plants. Using the procedures 
in Sec.  63.847 and in the approved test plan, the owner or operator 
shall monitor PM emissions from each paste production plant on an 
annual basis. The owner or operator shall compute and record the annual 
average of PM emissions from at least three runs to determine 
compliance with the applicable emission limits. The owner or operator 
must include all valid runs in the annual average.
    (o) Bag leak detection system. For each new affected source subject 
to a PM emissions limit, you must install, operate and maintain a bag 
leak detection system according to paragraphs (o)(1) through (3) of 
this section, unless a system meeting the requirements of paragraph (p) 
of this section, for a CEMS, is installed for monitoring the 
concentration of PM.
    (1) You must develop and implement written procedures for control 
device maintenance that include, at a minimum, a preventative 
maintenance schedule that is consistent with the control device 
manufacturer's instructions for routine and long-term maintenance.
    (2) Each bag leak detection system must meet the specifications and 
requirements in paragraphs (o)(2)(i) through (viii) of this section.
    (i) The bag leak detection system must be certified by the 
manufacturer to be capable of detecting PM emissions at concentrations 
of 1.0 milligram per dry standard cubic meter (0.00044 grains per 
actual cubic foot) or less.
    (ii) The bag leak detection system sensor must provide output of 
relative PM loadings.
    (iii) The bag leak detection system must be equipped with an alarm 
system that will alarm when an increase in relative particulate 
loadings is detected over a preset level.
    (iv) You must install, calibrate, operate and maintain the bag leak 
detection system according to the manufacturer's written specifications 
and recommendations.
    (v) The initial adjustment of the system must, at a minimum, 
consist of establishing the baseline output by adjusting the 
sensitivity (range) and the averaging period of the device and 
establishing the alarm set points and the alarm delay time.
    (vi) Following initial adjustment, you must not adjust the 
sensitivity or range, averaging period, alarm set points, or alarm 
delay time, except in accordance with the procedures developed under 
paragraph (o)(1) of this section. You cannot increase the sensitivity 
by more than 100 percent or decrease the sensitivity by more than 50 
percent over a 365-day period unless such adjustment follows a complete 
PM control device inspection that demonstrates that the PM control 
device is in good operating condition.
    (vii) You must install the bag leak detector downstream of the PM 
control device.
    (viii) Where multiple detectors are required, the system's 
instrumentation and alarm may be shared among detectors.
    (3) You must include in the written procedures required by 
paragraph (o)(1) of this section a corrective action plan that 
specifies the procedures to be followed in the case of a bag leak 
detection system alarm. The corrective action plan must include, at a 
minimum, the procedures that you will use to determine and record the 
time and cause of the alarm as well as the corrective actions taken to 
minimize emissions as specified in paragraphs (o)(3)(i) and (ii) of 
this section.
    (i) The procedures used to determine the cause of the alarm must be 
initiated within 1 hour of the alarm.
    (ii) The cause of the alarm must be alleviated by taking the 
necessary corrective action(s) that may include, but not be limited to, 
those listed in paragraphs (o)(3)(ii)(A) through (F) of this section.
    (A) Inspecting the PM control device for air leaks, torn or broken 
filter elements, or any other malfunction that may cause an increase in 
emissions.
    (B) Sealing off defective bags or filter media.
    (C) Replacing defective bags or filter media, or otherwise 
repairing the control device.
    (D) Sealing off a defective baghouse compartment.
    (E) Cleaning the bag leak detection system probe, or otherwise 
repairing the bag leak detection system.
    (F) Shutting down the process producing the particulate emissions.
    (p) Particulate Matter CEMS. If you are using a CEMS to measure 
particulate matter emissions to meet requirements of this subpart, you 
must install, certify, operate and maintain the particulate matter CEMS 
as specified in paragraphs (p)(1) through (4) of this section.
    (1) You must conduct a performance evaluation of the PM CEMS 
according to the applicable requirements of Sec.  60.13, and 
Performance Specification 11 at 40 CFR part 60, Appendix B of this 
chapter.
    (2) During each PM correlation testing run of the CEMS required by 
Performance Specification 11 at 40 CFR part 60, Appendix B of this 
chapter, collect data concurrently by both the CEMS and by conducting 
performance tests using Method 5, 5D or 5I at 40 CFR part 60, Appendix 
A-3.
    (3) Operate and maintain the CEMS in accordance with Procedure 2 at 
40 CFR part 60, Appendix F of this chapter. Relative Response Audits 
must be performed annually and Response Correlation Audits must be 
performed every three years.

0
11. Section 63.849 is amended by:
0
a. Revising paragraph (a) introductory text, and paragraphs (a)(6) and 
(a)(7); and
0
b. Adding paragraphs (a)(8) through (14), and (f).
    The revisions and additions read as follows:

[[Page 62422]]

Sec.  63.849  Test methods and procedures.

    (a) The owner or operator shall use the following reference methods 
to determine compliance with the applicable emission limits for TF, 
POM, PM, Ni, As, Hg, PCB and conduct visible emissions observations:
* * * * *
    (6) Method 315 in appendix A to this part or an approved 
alternative method for the concentration of POM where stack or duct 
emissions are sampled;
    (7) Method 315 in appendix A to this part and Method 14 or 14A in 
appendix A to part 60 of this chapter or an approved alternative method 
for the concentration of POM where emissions are sampled from roof 
monitors not employing wet roof scrubbers. Method 315 need not be set 
up as required in the method. Instead, when using Method 14A, replace 
the Method 14A monitor cassette filter with the filter specified by 
Method 315. Recover and analyze the filter according to Method 315. 
When using Method 14, test at ambient conditions, do not heat the 
filter and probe, and do not analyze the back half of the sampling 
train;
    (8) Method 5 in appendix A to part 60 of this chapter or an 
approved alternative method for the concentration of PM where stack or 
duct emissions are sampled;
    (9) Method 17 and Method 14 or Method 14A in appendix A to part 60 
of this chapter or an approved alternative method for the concentration 
of PM where emissions are sampled from roof monitors not employing wet 
roof scrubbers. Method 17 need not be set up as required in the method. 
Instead, when using Method 14A, replace the Method 14A monitor cassette 
filter with the filter specified by Method 17. Recover and analyze the 
filter according to Method 17. When using Method 14, test at ambient 
conditions, do not heat the filter and probe, and do not analyze the 
back half of the sampling train;
    (10) Method 29 in appendix A to part 60 of this chapter or an 
approved alternative method for the concentration of mercury, nickel 
and arsenic where stack or duct emissions are sampled;
    (11) Method 29 and Method 14 or Method 14A in appendix A to part 60 
of this chapter or an approved alternative method for the concentration 
of nickel and arsenic where emissions are sampled from roof monitors 
not employing wet roof scrubbers. Method 29 need not be set up as 
required in the method. Instead, replace the Method 14A monitor 
cassette filter with the filter specified by Method 29. Recover and 
analyze the filter according to Method 29. When using Method 14, test 
at ambient conditions, do not heat the filter and probe, and do not 
analyze the back half of the sampling train;
    (12) Method 22 in Appendix A to part 60 of this chapter or an 
approved alternative method for determination of visual emissions;
    (13) Method 428 of the California Air Resources Board (incorporated 
by reference; see Sec.  63.14) for the measurement of PCB where stack 
or duct emissions are sampled; and
    (14) Method 428 of the California Air Resources Board (incorporated 
by reference; see Sec.  63.14) and Method 14 or Method 14A in appendix 
A to part 60 of this chapter or an approved alternative method for the 
concentration of PCB where emissions are sampled from roof monitors not 
employing wet roof scrubbers.
* * * * *
    (f) The owner or operator must use either ASTM D4239-14e1 or ASTM 
D6376-10 (incorporated by reference; see Sec.  63.14) for determination 
of the sulfur content in anode coke shipments to determine compliance 
with the applicable emission limit for COS emissions.
0
12. Section 63.850 is amended by:
0
a. Revising paragraphs (b), (c), and (d);
0
b. Removing and reserving paragraph (e)(4)(iii);
0
c. Revising paragraphs (e)(4)(xiv) and (e)(4)(xv); and
0
d. Adding paragraphs (e)(4)(xvi), (e)(4)(xvii) and (f).
    The revisions and additions read as follows:

Sec.  63.850  Notification, reporting and recordkeeping requirements.

* * * * *
    (b) Performance test reports. Within 60 days after the date of 
completing each performance test (as defined in Sec.  63.2) required by 
this subpart, you must submit the results of the performance tests 
following the procedure specified in either paragraph (b)(1) or (b)(2) 
of this section.
    (1) For data collected using test methods supported by the EPA's 
Electronic Reporting Tool (ERT) as listed on the EPA's ERT Web site 
(http://www.epa.gov/ttn/chief/ert/index.html) at the time of the test, 
you 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/epa_home.asp). Performance test data must be submitted in a 
file format generated through the use of the EPA's ERT. Alternatively, 
you may submit performance test data in an electronic file format 
consistent with the extensible markup language (XML) schema listed on 
the EPA's ERT Web site once the XML schema is available. If you claim 
that some of the performance test information being submitted is 
confidential business information (CBI), you must submit a complete 
file generated 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/OAQPS/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.
    (2) 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, you must submit the results of the performance test to the 
Administrator at the appropriate address listed in Sec.  63.13.
    (3) For data collected which requires summation of results from 
both ERT and non-ERT supported test methods in order to demonstrate 
compliance with an emission limit, you must submit the results of the 
performance test(s) used to demonstrate compliance with that emission 
limit to the Administrator at the appropriate address listed in Sec.  
63.13.
    (c) Performance evaluation reports. Within 60 days after the date 
of completing each continuous emissions monitoring system performance 
evaluation (as defined in Sec.  63.2), you must submit the results of 
the performance evaluation following the procedure specified in either 
paragraph (c)(1) or (2) of this section.
    (1) For performance evaluations of continuous monitoring systems 
measuring relative accuracy test audit (RATA) pollutants that are 
supported by the EPA's ERT as listed on the EPA's ERT Web site at the 
time of the test, you must submit the results of the performance 
evaluation to the EPA via the CEDRI. (CEDRI can be accessed through the 
EPA's CDX.) Performance evaluation data must be submitted in a file 
format generated through the use of the EPA's ERT. Alternatively, you 
may submit performance evaluation data in an electronic file format 
consistent with the XML schema listed on the EPA's ERT Web site once 
the XML schema is available. If you claim that some of the

[[Page 62423]]

performance evaluation information being transmitted is CBI, you must 
submit a complete file generated 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 storage media must be clearly marked 
as CBI and mailed to U.S. EPA/OAQPS/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.
    (2) For any performance evaluations of continuous monitoring 
systems measuring RATA pollutants that are not supported by the EPA's 
ERT as listed on the EPA's ERT Web site at the time of the test, you 
must submit the results of the performance evaluation to the 
Administrator at the appropriate address listed in Sec.  63.13.
    (d) Reporting. In addition to the information required under Sec.  
63.10 of the General Provisions, the owner or operator must provide 
semiannual reports containing the information specified in paragraphs 
(d)(1) and (2) of this section to the Administrator or designated 
authority.
    (1) Excess emissions report. As required by Sec.  63.10(e)(3), the 
owner or operator must submit a report (or a summary report) if 
measured emissions are in excess of the applicable standard. The report 
must contain the information specified in Sec.  63.10(e)(3)(v) and be 
submitted semiannually unless quarterly reports are required as a 
result of excess emissions.
    (2) If there was a malfunction during the reporting period, the 
owner or operator must submit a report that includes the number, 
duration and a brief description for each type of malfunction which 
occurred during the reporting period and which caused or may have 
caused any applicable emission limitation to be exceeded. The report 
must also include a description of actions taken by an owner or 
operator during a malfunction of an affected source to minimize 
emissions in accordance with Sec. Sec.  63.843(f) and 63.844(f), 
including actions taken to correct a malfunction.
    (e) * * *
    (4) * * *
    (iii) [Reserved]
* * * * *
    (xiv) Records documenting any POM data that are invalidated due to 
the installation and startup of a cathode;
    (xv) Records documenting the portion of TF that is measured as 
particulate matter and the portion that is measured as gaseous when the 
particulate and gaseous fractions are quantified separately using an 
approved test method;
    (xvi) Records of the occurrence and duration of each malfunction of 
operation (i.e. process equipment) or the air pollution control 
equipment and monitoring equipment; and
    (xvii) Records of actions taken during periods of malfunction to 
minimize emissions in accordance with Sec. Sec.  63.843(f) and 
63.844(f), including corrective actions to restore malfunctioning 
process and air pollution control and monitoring equipment to its 
normal or usual manner of operation.
    (f) All reports required by this subpart not subject to the 
requirements in paragraph (b) or (c) of this section must be sent to 
the Administrator at the appropriate address listed in Sec.  63.13. If 
acceptable to both the Administrator and the owner or operator of a 
source, these reports may be submitted on electronic media. The 
Administrator retains the right to require submittal of reports subject 
to paragraph (b) of this section in paper format.

0
13. Section 63.854 is added to read as follows:

Sec.  63.854  Work practice standards for potlines.

    (a) Periods of operation other than startup. If you own or operate 
a new or existing primary aluminum reduction affected source, you must 
comply with the requirements of paragraphs (a)(1) through (8) of this 
section during periods of operation other than startup.
    (1) Ensure the potline scrubbers and exhaust fans are operational 
at all times.
    (2) Ensure that the primary capture and control system is operating 
at all times.
    (3) Hood covers should be replaced as soon as possible after each 
potroom operation.
    (4) Inspect potlines daily and perform the work practices specified 
in paragraphs (a)(4)(i) through (iii) of this section.
    (i) Identify unstable pots as soon as practicable but in no case 
more than 12 hours from the time the pot became unstable;
    (ii) Reduce cell temperatures to as low as practicable, and follow 
the written operating plan described in paragraph (b)(4) of this 
section if the cell temperature exceeds the specified high temperature 
limit; and
    (iii) Reseal pot crusts that have been broken as often and as soon 
as practicable.
    (5) Ensure that hood covers fit properly and are in good condition.
    (6) If the exhaust system is equipped with an adjustable damper 
system, the hood exhaust rate for individual pots must be increased 
whenever hood covers are removed from a pot, provided that the exhaust 
system will not be overloaded by placing too many pots on high exhaust.
    (7) Dust entrainment must be minimized during material handling 
operations and sweeping of the working aisles.
    (8) Only tapping crucibles with functional aspirator air return 
systems (for returning gases under the collection hooding) can be used, 
unless the regulatory authority approves an alternative tapping 
crucible.
    (b) Periods of startup. If you own or operate a new or existing 
primary aluminum reduction affected source, you must comply with the 
requirements of paragraphs (a)(1) through (8) and (b)(1) through (4) of 
this section during periods of startup for each affected potline.
    (1) Develop a potline startup schedule before starting up the 
potline.
    (2) Keep records of the number of pots started each day.
    (3) Inspect potlines daily and adjust pot parameters to their 
optimum levels, as specified in the operating plan described in 
paragraph (b)(4) of this section, including, but not limited to: 
alumina addition rate, exhaust air flow rate, cell voltage, feeding 
level, anode current and liquid and solid bath levels.
    (4) Prepare a written operating plan to minimize emissions during 
startup to include, but not limited to, the requirements in (b)(1) 
through (3) of this section. The operating plan must include a 
specified high temperature limit for pots that will trigger corrective 
action.

0
14. Section 63.855 is added to read as follows:

Sec.  63.855  Alternative emissions limits for co-controlled new and 
existing anode bake furnaces.

    (a) Applicability. The owner or operator of a new anode bake 
furnace meeting the criteria of paragraphs (a)(1) and (2) of this 
section may demonstrate compliance with alternative TF and POM emission 
limits according to the procedures of this section.
    (1) The new anode bake furnace must have been permitted to operate 
prior to May 1, 1998; and

[[Page 62424]]

    (2) The new anode bake furnace must share a common control device 
with one or more existing anode bake furnaces.
    (b) TF emission limit. (1) Prior to the date on which each TF 
emission test is required to be conducted, the owner or operator must 
determine the applicable TF emission limit using Equation 6-A,
[GRAPHIC] [TIFF OMITTED] TR15OC15.004

Where:

LTFC = Combined emission limit for TF, lb/ton green anode 
material placed in the bake furnace;
LTFE = TF limit for emission averaging for the total 
number of new and existing anode bake furnaces from Table 4 to this 
subpart;
PE = Mass of green anode placed in existing anode bake 
furnaces in the twelve months preceding the compliance test, ton/
year; and
PN = Mass of green anode placed in new anode bake 
furnaces in the twelve months preceding the compliance test, ton/
year.

    (2) The owner or operator of a new anode bake furnace that is 
controlled by a control device that also controls emissions of TF from 
one or more existing anode bake furnaces must not discharge, or cause 
to be discharged into the atmosphere, any emissions of TF in excess of 
the emission limits established in paragraph (b)(1) of this section.
    (c) POM emission limits. (1) Prior to the date on which each POM 
emission test is required to be conducted, the owner or operator must 
determine the applicable POM emission limit using Equation 6-B,
[GRAPHIC] [TIFF OMITTED] TR15OC15.005

Where:

    LPOMC = Combined emission limit for POM, lb/ton green 
anode material placed in the bake furnace.

    (2) The owner or operator of a new anode bake furnace that is 
controlled by a control device that also controls emissions of POM from 
one or more existing anode bake furnaces must not discharge, or cause 
to be discharged into the atmosphere, any emissions of TF in excess of 
the emission limits established in paragraph (c)(1) of this section.

0
15. Table 1 to Subpart LL of Part 63 is revised to read as follows:

                                       Table 1 to Subpart LL of Part 63--Potline TF Limits for Emission Averaging
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                    Semiannual TF limit (lb/ton) [for given number of potlines]
                  Type                   ---------------------------------------------------------------------------------------------------------------
                                              2 lines         3 lines         4 lines         5 lines         6 lines         7 lines         8 lines
--------------------------------------------------------------------------------------------------------------------------------------------------------
CWPB1...................................             1.7             1.6             1.5             1.5             1.4             1.4             1.4
CWPB2...................................             2.9             2.8             2.7             2.7             2.6             2.6             2.6
CWPB3...................................             2.3             2.2             2.2             2.1             2.1             2.1             2.1
SWPB....................................             1.4             1.3             1.3             1.2             1.2             1.2             1.2
VSS2....................................             2.6             2.5             2.5             2.4             2.4             2.4             2.4
--------------------------------------------------------------------------------------------------------------------------------------------------------

0
16. Table 2 to Subpart LL of Part 63 is revised to read as follows:

                                       Table 2 to Subpart LL of Part 63--Potline POM Limits for Emission Averaging
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                   Semiannual POM limit (lb/ton) [for given number of potlines]
                  Type                   ---------------------------------------------------------------------------------------------------------------
                                              2 lines         3 lines         4 lines         5 lines         6 lines         7 lines         8 lines
--------------------------------------------------------------------------------------------------------------------------------------------------------
CWPB1...................................               1             0.9             0.9             0.9             0.8             0.8             0.8
CWPB2...................................            11.6            11.2            10.8            10.8            10.4            10.4            10.4
CWPB3...................................             2.5             2.4             2.4             2.3             2.3             2.3             2.3
SWPB....................................            14.8            13.8            13.8            13.8            13.8            13.8            13.8
VSS2....................................             1.7             1.6             1.5             1.5             1.4             1.4             1.4
--------------------------------------------------------------------------------------------------------------------------------------------------------

0
17. Table 3 to Subpart LL of Part 63 is redesignated as Table 4 to 
Subpart LL of Part 63 and revised to read as follows:

               Table 4 to Subpart LL of Part 63--Anode Bake Furnace Limits for Emission Averaging
----------------------------------------------------------------------------------------------------------------
                                                                         Emission limit (lb/ton of anode)
                       Number of furnaces                        -----------------------------------------------
                                                                        TF              POM             PM
----------------------------------------------------------------------------------------------------------------
2...............................................................            0.11            0.17            0.11

[[Page 62425]]

 
3...............................................................            0.09            0.17           0.091
4...............................................................           0.077            0.17           0.076
5...............................................................            0.07            0.17           0.071
----------------------------------------------------------------------------------------------------------------

0
18. New Table 3 to Subpart LL of Part 63 is added to read as follows:

                                       Table 3 to Subpart LL of Part 63--Potline PM Limits for Emission Averaging
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                    Semiannual PM limit (lb/ton) [for given number of potlines]
                  Type                   ---------------------------------------------------------------------------------------------------------------
                                              2 lines         3 lines         4 lines         5 lines         6 lines         7 lines         8 lines
--------------------------------------------------------------------------------------------------------------------------------------------------------
CWPB1...................................             6.1             6.1             5.3             5.3             5.0             5.0             5.0
CWPB2...................................            10.6            10.3             9.9             9.9             9.5             9.5             9.5
CWPB3...................................            18.4            17.6            17.6            16.8            16.8            16.8            16.8
SWPB....................................             4.3             3.9             3.9             3.7             3.7             3.7             3.7
VSS2....................................              25            24.1            24.1            23.1            23.1            23.1            23.1
--------------------------------------------------------------------------------------------------------------------------------------------------------

0
19. Appendix A to Subpart LL of Part 63 is revised to read as follows:

      Appendix A to Subpart LL of Part 63--Applicability of General Provisions (40 CFR Part 63, Subpart A)
----------------------------------------------------------------------------------------------------------------
       Reference section(s)                 Requirement         Applies to subpart LL           Comment
----------------------------------------------------------------------------------------------------------------
63.1(a)(1) through (4)............  General Applicability.....  Yes..................
63.1(a)(5)........................  ..........................  No...................  [Reserved].
63.1(a)(6)........................  ..........................  Yes..................
63.1(a)(7) through (9)............  ..........................  No...................  [Reserved].
63.1(a)(10) through (12)..........  ..........................  Yes..................
63.1(b)(1) through (3)............  Initial Applicability       Yes..................  (b)(2) Reserved.
                                     Determination.
63.1(c)(1)........................  Applicability after         Yes..................
                                     standard Established.
63.1(c)(2)........................  ..........................  Yes..................  Area sources are not
                                                                                        subject to this subpart.
63.1(c)(3) and (4)................  ..........................  No...................  [Reserved].
63.1(c)(5)........................  ..........................  Yes..................
63.1(d)...........................  ..........................  No...................  [Reserved].
63.1(e)...........................  Applicability of Permit     Yes..................
                                     Program.
63.2..............................  Definitions...............  Yes..................  Reconstruction defined in
                                                                                        Sec.   63.842.
63.3..............................  Units and Abbreviations...  Yes..................
63.4(a)(1) and (2)................  Prohibited activities.....  Yes..................
63.4(a)(3) through (5)............  ..........................  No...................  [Reserved].
63.4(b) and (c)...................  Circumvention/Severability  Yes..................
63.5(a)...........................  Construction/               Yes..................
                                     Reconstruction
                                     Applicability.
63.5(b)(1)........................  Existing, New,              Yes..................
                                     Reconstructed Sources
                                     Requirements.
63.5(b)(2)........................  ..........................  No...................  [Reserved].
63.5(b)(3) and (4)................  ..........................  Yes..................
63.5(b)(5)........................  ..........................  No...................  [Reserved].
63.5(b)(6)........................  ..........................  Yes..................
63.5(c)...........................  ..........................  No...................  [Reserved].
63.5(d)...........................  Application for Approval    Yes..................
                                     of Construction/
                                     Reconstruction.
63.5(e)...........................  Approval of Construction/   Yes..................
                                     Reconstruction.
63.5(f)...........................  Approval of Construction/   Yes..................
                                     Reconstruction Based on
                                     State Review.
63.6(a)...........................  Compliance with Standards   Yes..................
                                     and Maintenance
                                     Applicability.
63.6(b)(1) through (5)............  New and Reconstructed       Yes..................  See Sec.   847(a)(6) and
                                     Source Dates.                                      (7).
63.6(b)(6)........................  ..........................  No...................  [Reserved].
63.6(b)(7)........................  ..........................  Yes..................
63.6(c)(1)........................  Existing Source Dates.....  No...................  See Sec.   847(a).
63.6(c)(2)........................  ..........................  Yes..................
63.6(c)(3) and (4)................  ..........................  No...................  [Reserved].
63.6(c)(5)........................  ..........................  Yes..................
63.6(d)...........................  ..........................  No...................  [Reserved].

[[Page 62426]]

 
63.6(e)(1)(i).....................  ..........................  No...................  See Sec.  Sec.
                                                                                        63.843(f) and 63.844(f)
                                                                                        for general duty
                                                                                        requirement.
63.6(e)(1)(ii)....................  ..........................  No...................
63.6(e)(1)(iii)...................  ..........................  Yes..................
63.6(e)(2)........................  ..........................  No...................  [Reserved].
63.6(e)(3)........................  Startup, Shutdown and       No...................
                                     Malfunction Plan.
63.6(f)(1)........................  Compliance with Emissions   No...................
                                     Standards.
63.6(f)(2)........................  Methods/Finding of          Yes..................
                                     Compliance.
63.6(g)...........................  Alternative Standard......  Yes..................
63.6(h)...........................  Compliance with Opacity/VE  Only in Sec.   63.845  Opacity standards
                                     Standards.                                         applicable only when
                                                                                        incorporating the NSPS
                                                                                        requirements under Sec.
                                                                                         63.845.
63.6(i)(1) through (14)...........  Extension of Compliance...  Yes..................
63.6(i)(15).......................  ..........................  No...................  [Reserved].
63.6(i)(16).......................  ..........................  Yes..................
63.6(j)...........................  Exemption from Compliance.  Yes..................
63.7(a)...........................  Performance Test            Yes..................
                                     Requirements
                                     Applicability.
63.7(b)...........................  Notification..............  Yes..................
63.7(c)...........................  Quality Assurance/Test      Yes..................
                                     Plan.
63.7(d)...........................  Testing facilities........  Yes..................
63.7(e)(1)........................  Conduct of Tests..........  No...................  See Sec.   63.847(d).
63.7(e)(2) through (4)............  ..........................  Yes..................
63.7(f), (g), (h).................  Alternative Test Method...  Yes..................
63.8(a)(1) and (2)................  Monitoring Requirements     Yes..................
                                     Applicability.
63.8(a)(3)........................  ..........................  No...................  [Reserved].
63.8(b)...........................  Conduct of Monitoring.....  Yes..................
63.8(c)(1)(i).....................  ..........................  No...................  See Sec.  Sec.
                                                                                        63.843(f) and 63.844(f)
                                                                                        for general duty
                                                                                        requirement.
63.8(c)(1)(ii)....................  ..........................  Yes..................
63.8(c)(1)(iii)...................  ..........................  No...................
63.8(c)(2) through (d)(2).........  ..........................  Yes..................
63.8(d)(3)........................  ..........................  Yes, except for last
                                                                 sentence.
63.8(e) through (g)...............  ..........................  Yes..................
63.9(a)...........................  Notification Requirements   Yes..................
                                     Applicability.
63.9(b)...........................  Initial Notifications.....  Yes..................  Notification of re-start
                                                                                        specified in Sec.
                                                                                        63.850(a)(9).
63.9(c)...........................  Request for Compliance      Yes..................
                                     Extension.
63.9(d)...........................  New Source Notification     Yes..................
                                     for Special Compliance
                                     Requirements.
63.9(e)...........................  Notification of             No...................
                                     Performance Test.
63.9(f)...........................  Notification of VE/Opacity  No...................
                                     Test.
63.9(g)...........................  Additional CMS              No...................
                                     Notifications.
63.9(h)(1) through (3)............  Notification of Compliance  Yes..................
                                     Status.
63.9(h)(4)........................  ..........................  No...................  [Reserved].
63.9(h)(5) and (6)................  ..........................  Yes..................
63.9(i)...........................  Adjustment of Deadlines...  Yes..................
63.9(j)...........................  Change in Previous          Yes..................
                                     Information.
63.10(a)..........................  Recordkeeping/Reporting     Yes..................
                                     Applicability.
63.10(b)(1).......................  General Recordkeeping       Yes..................
                                     Requirements.
63.10(b)(2)(i)....................  ..........................  No...................
63.10(b)(2)(ii)...................  ..........................  No...................  See Sec.  Sec.
                                                                                        63.850(e)(4)(xvi) and
                                                                                        (xvii) for recordkeeping
                                                                                        of occurrence and
                                                                                        duration of malfunctions
                                                                                        and recordkeeping of
                                                                                        actions taken during
                                                                                        malfunction.
63.10(b)(2)(iii)..................  ..........................  Yes..................
63.10(b)(2)(iv) and (v)...........  ..........................  No...................
63.10(b)(2)(vi) through (xiv).....  ..........................  Yes..................
63.(10)(b)(3).....................  ..........................  Yes..................
63.10(c)(1) through (9)...........  ..........................  Yes..................
63.10(c)(10) and (11).............  ..........................  No...................  See Sec.  Sec.
                                                                                        63.850(e)(4)(xvi) and
                                                                                        (xvii) for recordkeeping
                                                                                        of malfunctions.
63.10(c)(12) through (14).........  ..........................  Yes..................
63.10(c)(15)......................  ..........................  No...................
63.10(d)(1).......................  General Reporting           Yes..................
                                     Requirements.
63.10(d)(2).......................  ..........................  No...................  See Sec.   63.850(b).
63.10(d)(3) and (4)...............  ..........................  Yes..................
63.10(d)(5).......................  Startup-Shutdown and        No...................  See Sec.   63.850(d)(2)
                                     Malfunction Reports.                               for reporting of
                                                                                        malfunctions.

[[Page 62427]]

 
63.10(e) and (f)..................  Additional CMS Reports and  Yes..................
                                     Recordkeeping/Reporting
                                     Waiver.
63.11.............................  Control Device/work         No...................
                                     practices requirements
                                     Applicability.
63.12.............................  State Authority and         Yes..................
                                     Delegations.
63.13.............................  Addresses.................  Yes..................
63.14.............................  Incorporation by Reference  Yes..................
63.15.............................  Information Availability/   Yes..................
                                     Confidentiality.
63.16.............................  Performance Track           No...................
                                     Provisions.
----------------------------------------------------------------------------------------------------------------

[FR Doc. 2015-25137 Filed 10-14-15; 8:45 am]
 BILLING CODE 6560-50-P
```