[Federal Register Volume 80, Number 125 (Tuesday, June 30, 2015)]
[Rules and Regulations]
[Pages 37365-37401]
[FR Doc No: 2015-15038]

Vol. 80

Tuesday,

No. 125

June 30, 2015

Part II

Environmental Protection Agency

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40 CFR Part 63

National Emissions Standards for Hazardous Air Pollutants: Ferroalloys
Production; Final Rule

Federal Register / Vol. 80 , No. 125 / Tuesday, June 30, 2015 / Rules
and Regulations

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 63

[EPA-HQ-OAR-2010-0895; FRL-9928-66-OAR]
RIN 2060-AQ11

National Emissions Standards for Hazardous Air Pollutants:
Ferroalloys Production

AGENCY: Environmental Protection Agency (EPA).

ACTION: Final rule.

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SUMMARY: This action finalizes the residual risk and technology review
(RTR) conducted for the Ferroalloys Production source category
regulated under national emission standards for hazardous air
pollutants (NESHAP). These final amendments include revisions to
particulate matter (PM) standards for electric arc furnaces, metal
oxygen refining processes, and crushing and screening operations, and
expand and revise the requirements to control process fugitive
emissions from furnace operations, tapping, casting, and other
processes. We are also finalizing opacity limits, as proposed in 2014.
However, regarding opacity monitoring, in lieu of Method 9, we are
requiring monitoring with the digital camera opacity technique (DCOT).
Furthermore, we are finalizing emissions standards for four previously
unregulated hazardous air pollutants (HAP): Formaldehyde, hydrogen
chloride (HCl), mercury (Hg) and polycyclic aromatic hydrocarbons
(PAH). Other requirements related to testing, monitoring, notification,
recordkeeping, and reporting are included. This rule is health
protective due to the revised emissions limits for the stacks and the
requirement of enhanced fugitive emissions controls that will achieve
significant reductions of process fugitive emissions, especially
manganese.

DATES: This final action is effective on June 30, 2015. The
incorporation by reference of certain publications listed in the rule
is approved by the Director of the Federal Register as of June 30,
2015.

ADDRESSES: The Environmental Protection Agency (EPA) has established a
docket for this action under Docket ID No. EPA-HQ-OAR-2010-0895. 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<PHONE_NUMBER>, and
the telephone number for the Air Docket is<PHONE_NUMBER>.

FOR FURTHER INFORMATION CONTACT: For questions about this final action,
contact Phil Mulrine, 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:<PHONE_NUMBER>; fax number:<PHONE_NUMBER>; and email
address<EMAIL_ADDRESS>For specific information regarding the
risk modeling methodology, contact Darcie Smith, 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:<PHONE_NUMBER>;
fax number:<PHONE_NUMBER>; and email address<EMAIL_ADDRESS>
For information about the applicability of the NESHAP to a particular
entity, contact Cary Secrest, Office of Enforcement and Compliance
Assurance, U.S. Environmental Protection Agency, EPA WJC Building, 1200
Pennsylvania Ave. NW., Washington, DC 20460; telephone number: (202)
564-8661; and email address<EMAIL_ADDRESS>
SUPPLEMENTARY INFORMATION:

Preamble Acronyms and Abbreviation

    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:

ATSDR Agency for Toxic Substances and Disease Registry
BLDS bag leak detection system
BTF Beyond-the-Floor
CAA Clean Air Act
CBI Confidential Business Information
CFR Code of Federal Regulations
EJ environmental justice
EPA Environmental Protection Agency
ERPG Emergency Response Planning Guidelines
ERT Electronic Reporting Tool
FeMn Ferromanganese
FR Federal Register
HAP hazardous air pollutants
HCl hydrochloric acid
HI Hazard Index
HQ Hazard Quotient
ICR Information Collection Request
IRIS Integrated Risk Information System
km kilometer
MACT maximum achievable control technology
mg/dscm milligrams per dry standard cubic meter
mg/m\3\ milligrams per cubic meter
MIR maximum individual risk
MOR metal oxygen refining
MRL Minimal Risk Level
NAAQS National Ambient Air Quality Standards
NAICS North American Industry Classification System
NESHAP National Emissions Standards for Hazardous Air Pollutants
NTTAA National Technology Transfer and Advancement Act
OAQPS Office of Air Quality Planning and Standards
OECA Office of Enforcement and Compliance Assurance
OMB Office of Management and Budget
PAH polycyclic aromatic hydrocarbons
PB-HAP hazardous air pollutants known to be persistent and bio-
accumulative in the environment
PM particulate matter
POM polycyclic organic matter
REL reference exposure level
RFA Regulatory Flexibility Act
RfC reference concentration
RTR residual risk and technology review
SAB Science Advisory Board
SBA Small Business Administration
SiMn Silicomanganese
SSM startup, shutdown, and malfunction
TOSHI target organ-specific hazard index
TPY tons per year
TRIM.FaTE Total Risk Integrated Methodology.Fate, Transport, and
Ecological Exposure model
TTN Technology Transfer Network
[mu]g/dscm micrograms per dry standard cubic meter
[mu]g/m\3\ micrograms per cubic meter
UMRA Unfunded Mandates Reform Act
UPL Upper Prediction Limit
VCS voluntary consensus standards

Background Information

    On November 23, 2011, and October 6, 2014, the EPA proposed
revisions to the Ferroalloys Production NESHAP based on our RTR. In
this action, we are finalizing decisions and revisions for the NESHAP.
We summarize some of the more significant comments we timely received
regarding the proposed rule and provide our responses in this preamble.
A summary of all other public comments on the proposal and the EPA's
responses to those comments are available in document titled: National
Emission Standards for Hazardous Air Pollutant Emissions: Ferroalloys
Production Summary of Public

Comments and the EPA's Responses on Proposed Rule (76 FR 72508,
November 23, 2011) and Supplemental Proposal (79 FR 60238, October 6,
2014), Docket ID No. EPA-HQ-OAR-2010-0895, which is available in the
docket. A ``track changes'' version of the regulatory language that
incorporates the changes in this action is also available in the
docket.
    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 Ferroalloys Production source category and how
does the NESHAP regulate HAP emissions from the source category?
    C. What changes did we propose for the Ferroalloys Production
source category in our November 23, 2011, proposal and our October
6, 2014, supplemental proposal?
III. What is included in this final rule?
    A. What are the final rule amendments based on the risk review
for the Ferroalloys Production source category?
    B. What are the final rule amendments based on the technology
review for the Ferroalloys Production source category?
    C. What are the final rule amendments pursuant to CAA section
112(d)(2) & (3) for the Ferroalloys Production source category?
    D. What are requirements during periods of startup, shutdown,
and malfunction?
    E. What other changes have been made to the 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?
IV. What is the rationale for our final decisions and amendments for
the Ferroalloys Production source category?
    A. Residual Risk Review for the Ferroalloys Production Source
Category
    B. Technology Review for the Ferroalloys Production Source
Category
    C. CAA Section 112(d)(2) & (3) Revisions for the Ferroalloys
Production Source Category
    D. What changes did we make to the Ferroalloys Production
opacity monitoring requirement?
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 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
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                                                              NAICS \a\
                NESHAP and source category                      Code
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Ferroalloys Production....................................       331112
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\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 40 CFR part 63, subpart XXX (National
Emission Standards for Hazardous Air Pollutants (NESHAP): Ferroalloys
Production). 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/ferroa/ferropg.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 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 August 31,
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 Clean Air Act (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, EPA WJC Building,
1200 Pennsylvania Ave. NW., Washington, DC 20460, with a copy to both
the person(s) listed in the preceding FOR FURTHER INFORMATION CONTACT
section, and the Associate General Counsel for the Air and Radiation
Law Office, Office of General Counsel (Mail Code 2344A), U.S. EPA, 1200
Pennsylvania Ave. NW., Washington, DC 20460.

II. Background

A. What is the statutory authority for this action?

    Section 112 of the CAA establishes a two-stage regulatory process
to address emissions of HAP from stationary sources. In the first
stage, we must identify categories of sources emitting one or more of
the HAP listed in CAA section 112(b) and then promulgate technology-
based NESHAP for those sources. ``Major sources'' are those that emit,
or have the potential to emit, any single HAP at a rate of 10 tons per
year (tpy) or more, or 25 tpy or more of any combination of HAP. For
major sources, these standards are commonly referred to as maximum
achievable control technology (MACT) standards and must reflect the
maximum degree of emission reductions of HAP achievable (after
considering cost, energy requirements, and non-air quality health and
environmental impacts). In developing MACT standards, CAA section
112(d)(2) directs the EPA to consider the application of measures,
processes, methods, systems, or techniques, 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. For existing sources the MACT standards can
be less stringent than the floors for new sources, but they cannot be
less stringent than the average emission limitation achieved by the
best-performing 12 percent of existing sources in the category or
subcategory (or the best-performing five sources for categories or
subcategories with fewer than 30 sources). In developing MACT
standards, we must also consider control options that are more
stringent than the floor, under CAA section 112(d)(2). We may establish
standards more stringent than the floor, based on the consideration of
the cost of achieving the emissions reductions, any non-air quality
health and environmental impacts, and energy requirements.
    In the second stage of the regulatory process, the CAA requires the
EPA to undertake two different analyses, which we refer to as the
technology review and the residual risk review. Under the technology
review, we must review the technology-based standards and revise them
``as necessary (taking into account developments in practices,
processes, and control technologies)'' no less frequently than every 8
years, pursuant to CAA section 112(d)(6). Under the residual risk
review, we must evaluate the risk to public health remaining after
application of the technology-based standards and revise the standards,
if necessary, to provide an ample margin of safety to protect public
health or to prevent, taking into consideration costs, energy, safety,
and other relevant factors, an adverse environmental effect. The
residual risk review is required within 8 years after promulgation of
the technology-based standards, pursuant to CAA section 112(f). In
conducting the residual risk review, if the EPA determines that the
current standards provide an ample margin of safety to protect public
health, it is not necessary to revise the MACT standards pursuant to
CAA section 112(f).\1\ For more information on the statutory authority
for this rule, see 79 FR 60238.
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    \1\ The U.S. Court of Appeals has affirmed this approach of
implementing CAA section 112(f)(2)(A); NRDC v. EPA, 529 F.3d 1077,
1083 (D.C. Cir. 2008) (``If EPA determines that the existing
technology-based standards provide an `ample margin of safety,' then
the Agency is free to readopt those standards during the residual
risk rulemaking.'').
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B. What is the Ferroalloys Production source category and how does the
NESHAP regulate HAP emissions from the source category?

    The EPA promulgated the Ferroalloys Production NESHAP on May 20,
1999 (64 FR 27450). The standards are codified at 40 CFR part 63,
subpart XXX. The ferroalloys production industry consists of facilities
that produce ferromanganese (FeMn) or silicomanganese (SiMn). The
source category covered by this MACT standard currently includes two
facilities.
    The rule applies to ferroalloys production operations that are
located at major sources of HAP emissions or are co-located at a major
source of HAP emissions. The HAP emission sources at facilities subject
to the Ferroalloys Production NESHAP are open, semi-sealed, or sealed
submerged arc furnaces, tapping operations, casting operations, metal
oxygen refining (MOR) process, crushing and screening operations, other
processes, such as ladle treatment and slag raking, and outdoor
fugitive dust sources. The 1999 NESHAP regulated these emissions
sources through emission limits for PM, opacity limits, and work
practices.

C. What changes did we propose for the Ferroalloys Production source
category in our November 23, 2011, proposal and our October 6, 2014,
supplemental proposal?

    On November 23, 2011, the EPA published a proposed rule in the
Federal Register (76 FR 72508) for the Ferroalloys Production NESHAP,
40 CFR part 63, subpart XXX that took into consideration the RTR
analyses. In the 2011 proposed rule, we proposed:
     Revisions to the numeric emission limits for PM from
furnace stacks to reflect the current performance of control devices in
place at ferroalloys production facilities to control furnace emissions
(primary and tapping), crushing and screening operations, and the MOR
operation at one plant;
     Addition of Hg, HCl, PAH, and formaldehyde furnace stack
emission standards that reflected the MACT determination for control of
these pollutants;
     Requirements to capture process fugitive emissions using
full building enclosure with negative pressure building ventilation and
duct the captured emissions to a control device; and
     Revisions to the opacity standards to reflect effective
capture and control of process fugitive emissions.
    On October 6, 2014, the EPA published a supplemental proposed rule
in the Federal Register (79 FR 60238). For the supplemental proposal,
we proposed:
     Revisions to the proposed PM furnace stack emission
standards based on additional test data submitted by the facilities;
     Revisions to the proposed Hg, HCl, and PAH furnace stack
emission standards based on additional test data submitted by the
facilities;
     Requirements to capture process fugitive emissions using
effective, enhanced local capture, and duct the captured emissions to
control devices;
     Revisions to the opacity standards to reflect effective,
enhanced capture, and control of process fugitive emissions;
     To demonstrate compliance with the opacity limits, we
proposed facilities would need to take opacity readings for an entire
furnace cycle once per week per furnace using Method 9 or

as an option they could take the readings using DCOT; and
     Several minor clarifications and corrections.

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 Ferroalloys Production source
category and amends the existing Ferroalloys Production NESHAP based on
those determinations. Among the changes finalized in this action are:
The promulgation of MACT-based limits for previously unregulated HAP;
requirements to effectively capture and control process fugitive
emissions; the removal of startup, shutdown, and malfunction (SSM)
exemptions; and the addition of DCOT monitoring. This action also
reflects several changes to the November 2011 and October 2014
proposals in consideration of comments 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
Ferroalloys Production source category?

    This section provides a summary of the final amendments to the
Ferroalloys Production NESHAP being promulgated pursuant to CAA section
112(f).
1. Stack Emissions
    We are promulgating PM emission limits for stacks at the following
levels: 4.0 milligrams per dry standard cubic meter (mg/dscm) for new
or reconstructed electric arc furnaces; 25 mg/dscm for existing
electric arc furnaces; and 4.0 mg/dscm for any new, reconstructed, or
existing local ventilation control device. These emission limits are
the same as the limits proposed in the 2014 supplemental proposal.
    In addition, we are promulgating a PM limit of 3.9 mg/dscm for any
new, reconstructed, or existing MOR process and a PM limit of 13 mg/
dscm for any new, reconstructed, or existing crushing and screening
equipment, which are consistent with what we proposed in our November
23, 2011, proposal.
2. Process Fugitive Emissions Sources
    We are promulgating a requirement that facilities in this source
category must achieve effective enhanced capture of process fugitive
emissions using a system of primary hoods (that capture process
fugitive emissions near the source) and/or secondary capture of
fugitives (which would capture remaining fugitive emissions near the
roof-line). Facilities must install, operate, and maintain a process
fugitives capture system that is designed to capture 95 percent or more
of the process fugitive emissions. We are also promulgating an opacity
limit of 8-percent to ensure process fugitive emissions are effectively
captured. This is what we proposed in the October 6, 2014, supplemental
proposal. However, we have revised the rule based on public comment, to
provide more flexibility on how facilities achieve 95-percent capture
of process fugitive emissions. We also strengthened the monitoring
provisions to ensure that the required reductions are achieved.

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

    We determined that there are developments in practices, processes,
and control technologies that warrant revisions to the MACT standards
for this source category for both stack PM emissions and process
fugitive emissions. Therefore, under the authority of CAA section
112(d)(6), we are promulgating the same PM stack emission limits and
enhanced fugitive control requirements that we are promulgating under
CAA section 112(f), as described in section A above.

C. What are the final rule amendments pursuant to CAA section 112(d)(2)
& (3) for the Ferroalloys Production source category?

    We are promulgating emission limits for formaldehyde, HCl, Hg, and
PAH, which were previously unregulated HAP, pursuant to CAA section
112(d)(2) and 112(d)(3).
    We are promulgating a formaldehyde emission limit of 201 micrograms
per dry standard cubic meter ([mu]g/dscm) for any new, reconstructed,
or existing electric arc furnace. This is the same limit that we
proposed on November 23, 2011.
    We are promulgating an HCl emission limit of 180 [mu]g/dscm for new
or reconstructed electric arc furnaces and 1,100 [mu]g/dscm for
existing electric arc furnaces. This is the same limit that we proposed
on October 6, 2014.
    For electric arc furnaces producing FeMn, we are promulgating Hg
emission limits of 13 [mu]g/dscm for new or reconstructed electric arc
furnaces and 130 [mu]g/dscm for existing electric arc furnaces. For
electric arc furnaces producing SiMn, we are promulgating Hg emission
limits of 4 [mu]g/dscm for new or reconstructed electric arc furnaces
and 12 [mu]g/dscm for existing electric arc furnaces. The Hg limit for
new SiMn furnaces is the same as in the October 6, 2014, supplemental
proposal. The final Hg limits for new and existing FeMn and existing
SiMn furnaces are generally consistent with the supplemental proposal;
however, there were changes to these three limits due to the inclusion
of new emission data we received shortly before or during the
supplemental proposal comment period.
    For electric arc furnaces producing FeMn, we are promulgating a PAH
emission limit of 12,000 [mu]g/dscm for new or reconstructed and
existing electric arc furnaces. The FeMn furnace PAH emission limits
are significantly higher than what we proposed in the October 6, 2014,
supplemental proposal due to the inclusion of new PAH emission data we
received a few weeks before signature of the supplemental proposal and
during the supplemental proposal comment period. We explained in the
supplemental proposal preamble that we received data shortly before
that notice and provided the data for comment (i.e., the data were
available in the docket). The data received during the comment period
were consistent with the data mentioned in the supplemental proposal.
For electric arc furnaces producing SiMn, we are promulgating a PAH
emission limit of 72 [mu]g/dscm for new or reconstructed electric arc
furnaces and 130 [mu]g/dscm for existing electric arc furnaces. The
SiMn furnace new PAH emission limit is the same as the limit in the
October 6, 2014, supplemental proposal. There was a slight revision to
the existing SiMn furnace PAH limit due to the inclusion of new
emission data we received during the supplemental proposal comment
period.

D. What are the requirements during periods of startup, shutdown and
malfunction?

    We are finalizing, as proposed in the supplemental proposal,
changes to the Ferroalloys Production NESHAP to eliminate the SSM
exemption. 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. Table 1 to subpart XXX of part 63 (General Provisions
applicability table) is being revised to change several references
related to requirements that apply during periods of SSM. We also are
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 determined
that facilities in this source category can meet the applicable
emission standards

in the Ferroalloys Production NESHAP at all times, including periods of
startup and shutdown; therefore, the EPA determined that no separate
standards are needed to address emissions during these periods.

E. What other changes have been made to the NESHAP?

    This rule also finalizes revisions to several other Ferroalloys
Production NESHAP requirements as proposed, or in some cases with some
modification as described in this section.
    To increase the ease and efficiency of data submittal and data
accessibility, we are finalizing, as proposed, a requirement that
owners and operators of ferroalloys production facilities 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.
    We are finalizing the opacity standards, as proposed in the
supplemental proposal. However, regarding compliance demonstration, we
are requiring that facilities measure opacity using DCOT. In the
supplemental proposal, we proposed facilities would need to monitor
opacity with Method 9 or DCOT. However, after considering public
comments, we decided to require DCOT rather than have it as optional.
Regarding monitoring frequency, we proposed facilities would need to do
opacity readings weekly per furnace building with no opportunity to
reduce frequency overtime. After considering public comments, we have
decided to require weekly readings initially, as proposed, but allow a
facility an opportunity to decrease frequency of opacity readings to
monthly per furnace building after 26 weeks of successful, compliant
opacity readings.
    In addition, due to the large variation in PAH emissions from
furnace stacks during FeMn production, we are requiring quarterly
compliance tests for PAHs (i.e., four PAH compliance tests per year)
for furnaces while producing FeMn, with an opportunity for facilities
to request decreased frequency of such compliance testing from their
permit authority after the first year and after four or more successful
PAH compliance tests have been completed and submitted electronically.
    We are also finalizing other minor 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 June 30, 2015. The compliance date for existing
ferroalloys production sources for all the requirements promulgated in
this final rule is June 30, 2017. Facilities must comply with the
changes set out in this final rule (which are being promulgated under
CAA sections 112(d)(2), 112(d)(3), 112(d)(6), and 112(f)(2) for all
affected sources) no later than 2 years after the effective date of the
final rule. CAA section 112(f)(4) generally provides that a standard
promulgated pursuant to CAA section 112(f)(2) applies 90 days after the
effective date, but further provides for a compliance period of up to 2
years when the Administrator determines that such time is necessary for
the installation of controls and that steps will be taken during that
period to assure protection to health from imminent endangerment. We
conclude that 2 years are necessary to complete the installation of the
enhanced local capture system and other controls. In the period between
the effective date of this rule and the compliance date, existing
sources will need to continue to comply with the requirements specified
in 40 CFR 63.1650 through 40 CFR 63.1660. New sources must comply with
the all of the standards immediately upon the effective date of the
standard, June 30, 2015, or upon startup, whichever is later.

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

    As we proposed, the EPA is taking a step to increase the ease and
efficiency of data submittal and data accessibility. Specifically, the
EPA is finalizing the requirement for owners and operators of
ferroalloys production facilities to submit electronic copies of
certain required performance test reports.
    Data will be collected by direct computer-to-computer electronic
transfer using EPA-provided software. This EPA-provided software is an
electronic performance test report tool called the ERT. The ERT will
generate an electronic report package which will be submitted to the
Compliance and Emissions Data Reporting Interface (CEDRI) and then
archived to the EPA's Central Data Exchange (CDX). A description and
instructions for use of the ERT can be found at http://www.epa.gov/ttn/chief/ert/index.html and CEDRI can be accessed through the CDX Web site
(http://www.epa.gov/cdx).
    The requirement to submit performance test data electronically to
the EPA does not create any additional performance testing and will
apply only to those performance tests conducted using test methods that
are supported by the ERT. A listing of the pollutants and test methods
supported by the ERT is available at the ERT Web site. The EPA
believes, through this approach, industry will save time in the
performance test submittal process. Additionally, this rulemaking
benefits industry by reducing recordkeeping costs as the performance
test reports that are submitted to the EPA using CEDRI are no longer
required to be kept in hard copy.
    State, local, and tribal agencies will benefit from more
streamlined and accurate review of performance test data that will
become available through WebFIRE. The public will also benefit. Having
these data publicly available enhances transparency and accountability.
For a more thorough discussion of electronic reporting of performance
tests using direct computer-to-computer electronic transfer and using
EPA-provided software, see the discussion in the preamble of the
proposal.
    In summary, in addition to supporting regulation development,
control strategy development, and other air pollution control
activities, having an electronic database populated with performance
test data will save industry, state, local, tribal agencies, and the
EPA significant time, money, and effort while improving the quality of
emission inventories and air quality regulations and enhancing the
public's access to this important information.

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

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

A. Residual Risk Review for the Ferroalloys Production Source Category

1. What did we propose pursuant to CAA section 112(f) for the
Ferroalloys 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 October 6, 2014, supplemental proposal for the Ferroalloys
Production NESHAP (79 FR 60238). The results of the risk assessment for
the 2014 supplemental proposal are presented briefly below in Table 2
and in more detail in the residual risk document, Residual Risk
Assessment for the Ferroalloys Source Category in Support of the
September 2014 Supplemental Proposal, which is available in the docket
for this rulemaking.
    Based on actual emissions estimates for the Ferroalloys Production
source category supplemental proposal, the maximum individual risk
(MIR) for cancer was estimated to be up to 20-in-1 million driven by
emissions of chromium compounds, PAHs, and nickel compounds. The
maximum chronic non-cancer target organ-specific hazard index (TOSHI)
value was estimated to be up to 4 driven by fugitive emissions of
manganese. The maximum off-site acute hazard quotient (HQ) value was
estimated to be 1 for arsenic compounds, hydrogen fluoride (HF), and
formaldehyde. The total estimated national cancer incidence from this
source category, based on actual emission levels, was 0.002 excess
cancer cases per year, or one case in every 500 years.
    Based on MACT-allowable emissions estimated for the Ferroalloys
Production source category supplemental proposal, the MIR was estimated
to be up to 100-in-1 million driven by emissions of arsenic and cadmium
compounds from the MOR process baghouse outlet. The maximum chronic
non-cancer TOSHI value was estimated to be up to 40 driven by emissions
of manganese from the MOR process. The total estimated national cancer
incidence from this source category, based on MACT-allowable emission
levels, was 0.005 excess cancer cases per year, or one case in every
200 years.
    We also found there were emissions of four persistent and
bioaccumulative HAP (PB-HAP) with an available RTR multipathway
screening value, and the reported emissions of these four HAP (cadmium
compounds, dioxins/furans, Hg compounds, and PAH) were greater than the
Tier 1 multipathway screening values for these compounds for both
facilities at the time of the supplemental proposal. We conducted a
Tier 2 multipathway screen for both facilities, and conducted a refined
multipathway assessment for one facility in the source category.
Results of the refined multipathway assessment predict a potential
lifetime cancer risk of 10-in-1 million to the maximum exposed
individual due to exposure to dioxins and PAHs. The non-cancer HQ was
predicted to be below 1 for cadmium compounds and 1 for Hg compounds.
    However, as explained in the Revised Development of the Risk and
Technology Review (RTR) Emissions Dataset for the Ferroalloys
Production Source Category for the 2014 Supplemental Proposal document,
it is important to note that about 75 percent of the emissions test
results for dioxins were below the detection limit. To be conservative,
in our calculations of emissions estimates, we assumed all the test
results that were recorded as below detection were one half the
detection limit. Therefore, there are considerable uncertainties in
estimated emissions for dioxins. Nevertheless, since we assumed
emissions were at the level of one half the detection limit in all
these cases where emissions were not even detected, we believe our
emissions estimates are conservative (i.e., more likely to be
overestimates rather than underestimates of the true emissions).
    Emissions of the four PB-HAP and two environmental HAP (HCl and HF)
were reported by ferroalloys facilities. Tier 1 results for PB-HAP
indicate that concentrations of cadmium compounds and dioxins are below
the ecological benchmarks. Mercury compounds and PAHs concentrations
were greater than the benchmark so a Tier 2 screen was conducted. For
PAH and methylmercury, none of the individual modeled concentrations
for any facility exceeded any of the ecological benchmarks. For
mercuric chloride, the weighted average modeled concentrations for all
soil parcels were well below the soil benchmarks. For HCl and HF, the
average modeled concentrations around each facility did not exceed any
ecological benchmarks.
    For the supplemental proposal, we weighed all health risk factors
in our risk acceptability determination and we proposed that the
residual risks from the Ferroalloys Production source category are
unacceptable.

                            Table 2--Ferroalloys Inhalation Risk Assessment Results in the October 2014 Supplemental Proposal
--------------------------------------------------------------------------------------------------------------------------------------------------------
Maximum individual cancer risk (in 1 million)                                                       Maximum chronic  non-
                     \a\                                                                              cancer TOSHI \b\
----------------------------------------------   Estimated population at      Estimated annual  ----------------------------
                                                 increased risk levels of     cancer incidence                     MACT-     Maximum screening acute non-
                              MACT- allowable             cancer              (cases per year)      Actual       allowable          cancer HQ \d\
  Actual  emissions  level        emissions                                                        emissions     emissions
                                 level \c\                                                           level         level
--------------------------------------------------------------------------------------------------------------------------------------------------------
20..........................             100   >= 1-in-1 million: 31,000..               0.002             4            40   HQREL = 1 (arsenic
                                               >= 10-in-1 million: 400....                                                    compounds, formaldehyde,
                                               >= 100-in-1 million: 0.....                                                    hydrofluoric acid).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\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 Ferroalloys Production source category for both actual and allowable emissions is the
  neurological system. The estimated population at increased levels of noncancer hazard is 1,500 based on actual emissions and 11,000 based on allowable
  emissions.
\c\ The development of allowable emission estimates can be found in the memorandum titled Revised Development of the RTR Emissions Dataset for the
  Ferroalloys Production Source Category for the 2014 Supplemental Proposal, which is available in the docket.
\d\ See section III.A.3 of the supplemental proposal or the risk assessment document supporting the supplemental proposal for explanation of acute dose-
  response values. Acute assessments are not performed on allowable emissions.

    As described above, to address the unacceptable risks in the
supplemental proposal, we proposed tighter PM emission limits for the
stacks, which significantly reduce risks due to allowable emissions. To
reduce risks

due to process fugitive emissions, we proposed facilities must achieve
effective enhanced capture of process fugitive emissions using a system
of primary hoods (that capture process fugitive emissions near the
source) and/or secondary capture of fugitives (which would capture
remaining fugitive emissions near the roof-line). As described in the
supplemental proposal, we estimated that these controls would reduce
the MIR cancer risk estimate to 10-in-1 million and that the chronic
noncancer hazard index (HI) would be reduced to an HI of 1. Acute
screening and multipathway results were also reduced. In the
supplemental proposal, we concluded that these risks, after the
implementation of proposed controls, were acceptable.
    We then considered whether the Ferroalloys Production NESHAP
provides an ample margin of safety to protect public health and whether
more stringent standards are necessary to prevent an adverse
environmental effect, taking into consideration costs, energy, safety,
and other relevant factors. In considering whether the standards should
be tightened to provide an ample margin of safety to protect public
health, we considered the same risk factors that we considered for our
acceptability determination and also considered the costs,
technological feasibility, and other relevant factors related to
emissions control options that might reduce risks associated with
emissions from the source category. Based on our ample margin of safety
analysis for the supplemental proposal, we did not identify any
additional cost-effective controls to further reduce risks beyond the
requirements we proposed to achieve acceptable risks. Therefore, we
proposed that additional HAP emissions controls are not necessary to
provide an ample margin of safety. Based on the results of our
screening analysis for risks to the environment, we also proposed that
more stringent standards are not necessary to prevent an adverse
environmental effect.
2. How did the risk review change for the Ferroalloys Production source
category?
    Information received by the EPA shortly before and during the
supplemental proposal comment period included additional PAH and Hg
test data that were not included in the supplemental proposal risk
assessment due to timing and the need to review the data. We described
the data in the supplemental proposal and asked for comment on the use
of these data. After completion of the data review, these data were
included in the risk assessment for the final rule. Therefore, PAH and
Hg emissions estimates were revised for the final rule assessment. Some
revisions were also made for other HAP emissions. These changes are
discussed further in section IV of this preamble.
    With the exception of the revised emissions described above, the
risk assessment supporting the final rule was conducted in the same
manner, using the same models and methods, as that conducted for the
supplemental proposal. The documentation for the final rule risk
assessment can be found in the document titled Residual Risk Assessment
for the Ferroalloys Source Category in Support of the 2015 Risk and
Technology Review Final Rule, which is available in the docket for this
rulemaking.
    a. Inhalation Risk Assessment Results. Table 3 provides an overall
summary of the results of the inhalation risk assessment supporting the
final rule.

                                     Table 3--Ferroalloys Inhalation Risk Assessment Results in the 2015 Final Rule
--------------------------------------------------------------------------------------------------------------------------------------------------------
Maximum individual cancer risk (in 1 million)                                                    Maximum chronic non-cancer
                     \a\                                                                                TOSHI \b\
----------------------------------------------   Estimated population at      Estimated annual  ----------------------------
                                                 increased risk levels of     cancer incidence                     MACT-     Maximum screening acute non-
                              MACT- allowable             cancer              (cases per year)      Actual       allowable          cancer HQ \d\
   Actual emissions level     emissions level                                                      emissions     emissions
                                    \c\                                                              level         level
--------------------------------------------------------------------------------------------------------------------------------------------------------
20..........................             100   >= 1-in-1 million: 41,000..               0.003             4            40   HQREL = 1 (hydrofluoric
                                               >= 10-in-1 million: 90.....                                                    acid, arsenic compounds).
                                               >= 100-in-1 million: 0.....
--------------------------------------------------------------------------------------------------------------------------------------------------------
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 Ferroalloys Production source category for both actual and allowable emissions is the
  neurological system. The estimated population at increased levels of noncancer hazard is 1,300 based on actual emissions and 11,000 based on allowable
  emissions.
c The development of allowable emission estimates can be found in the memorandum titled Revised Development of the RTR Emissions Dataset for the
  Ferroalloys Production Source Category for the 2014 Supplemental Proposal, which is available in the docket.
d See section III.A.3 of the supplemental proposal or the risk assessment document supporting the supplemental proposal for explanation of acute dose-
  response values. Acute assessments are not performed on allowable emissions.

    The inhalation risk modeling performed to estimate risks based on
actual and allowable emissions for the final rule relied primarily on
updated emissions estimates based on data received through two
Information Collection Requests (ICRs), additional data submitted by
the companies voluntarily, and revised calculations as described
further in the Revised Development of the Risk and Technology Review
(RTR) Emissions Dataset for the Ferroalloys Production Source Category
for the 2015 Final Rule, which is available in the docket for this
action.
    The results of the chronic baseline inhalation cancer risk
assessment indicate that, based on updated estimates of actual
emissions, the cancer MIR posed by the Ferroalloys Production source
category is 20-in-1 million, with chromium compounds, PAHs, and nickel
compounds from tapping fugitives, furnace fugitives, and furnace stacks
accounting for more than 70 percent of the MIR. The total estimated
cancer incidence from ferroalloys production sources based on updated
actual emission levels is 0.003 excess cancer cases per year, or one
case every 333 years, with emissions of PAH, chromium compounds, and
cadmium compounds contributing 49 percent, 15 percent, and 12 percent,
respectively, to this cancer incidence. In addition, we note that
approximately 90 people are estimated to have cancer risks greater than
or equal to 10-in-1 million, and approximately 41,000 people are
estimated to have risks greater than or equal to 1-in-1 million because
of actual emissions from this source category. These results, based on
updated actual

emissions, are very similar to those presented in the supplemental
proposal.
    When considering the updated MACT-allowable emissions, the maximum
individual lifetime cancer risk is estimated to be up to 100-in-1
million, driven by emissions of arsenic and cadmium compounds from the
MOR process baghouse outlet. The estimated cancer incidence is
estimated to be 0.006 excess cancer cases per year or one excess case
in every 167 years. Approximately 3,300 people are estimated to have
cancer risks greater than or equal to 10-in-1 million and approximately
120,000 people are estimated to have cancer risks greater than or equal
to 1-in-1 million considering updated allowable emissions from
ferroalloys facilities. These results, based on updated MACT-allowable
emissions, are very similar to those presented in the supplemental
proposal.
    The maximum modeled chronic non-cancer HI (TOSHI) value for the
source category based on updated actual emissions is estimated to be 4,
with manganese emissions from tapping fugitives accounting for more
than 50 percent of the HI. Approximately 1,300 people are estimated to
have exposure to HI levels greater than 1 as a result of updated actual
emissions from this source category. When considering updated MACT-
allowable emissions, the maximum chronic non-cancer TOSHI is estimated
to be 40, driven by manganese emissions from the MOR process baghouse
outlet. Approximately 12,000 people are estimated to have potential
exposure to TOSHI levels greater than 1 considering updated allowable
emissions from these ferroalloys facilities. These results, for both
updated actual and MACT-allowable emissions, are very similar to those
presented in the supplemental proposal.
    b. Acute Risk Results. Based on the updated emissions described
above, our screening analysis for worst-case acute impacts based on
actual emissions indicates the potential for hydrofluoric acid and
arsenic compounds to have HQ results of 1, based on their respective
REL values. Both facilities have estimated acute HQs of 1 for these
pollutants. Acute HQs for other pollutants (e.g., hydrochloric acid)
are less than one. These acute results, based on updated emissions, are
very similar to those presented in the supplemental proposal.
    All the HAP in this analysis have worst-case acute HQ values of 1
or less, indicating that they carry no potential to pose acute
concerns. In characterizing the potential for acute non-cancer impacts
of concern, it is important to remember the upward bias of these
exposure estimates (e.g., worst-case meteorology coinciding with a
person located at the point of maximum concentration during the hour)
and to consider the results along with the conservative estimates used
to develop peak hourly emissions as described earlier, as well as the
screening methodology. More discussion of our acute screening methods
can be found in the supplemental proposal or in the risk assessment
document, Residual Risk Assessment for the Ferroalloys Production
Source Category in Support of the 2015 Final Rule, which are available
in the docket.
    c. Multipathway Risk Screening Results. Results of the worst-case
Tier I screening analysis indicate that PB-HAP emissions (based on
updated estimates of actual emissions) from one or both facilities in
this source category exceed the screening emission rates for cadmium
compounds, Hg compounds, dioxins, and PAHs. For the compounds and
facilities that did not screen out at Tier I, we conducted a Tier II
screen.
    Based on the Tier II screening analysis, no facility emits cadmium
compounds above the Tier II screening levels. One facility emits Hg
compounds above the Tier II screening levels and exceeds that level by
a factor of 8. Both facilities emit chlorinated dibenzodioxins and
furans (CDDF) as 2,3,7,8-tetrachlorodibenzo-p-dioxin toxicity
equivalent (TEQ) above the Tier II screening levels and the facility
with the highest emissions of dioxins exceeds its Tier II screening
level by a factor of 10. Both facilities emit POM as benzo(a)pyrene TEQ
above the Tier II screening levels and the facility with the highest
emissions exceeds its screening level by a factor of 50. These
multipathway screening results, based on updated emissions, are very
similar to those presented in the supplemental proposal. More
information about our multipathway screening approach can be found in
the supplemental proposal or in the risk assessment document, Residual
Risk Assessment for the Ferroalloys Production Source Category in
Support of the 2015 Final Rule, which are available in the docket.
    d. Multipathway Refined Risk Results. A refined multipathway
analysis was conducted for one of the two facilities in this source
category using the TRIM.FaTE model and the updated emissions as
described above. The facility, Eramet Marietta Incorporated, in
Marietta, Ohio, was selected based upon its close proximity to nearby
lakes, and farms as well as having the highest potential multipathway
risks for three of the four PB-HAP based on the Tier II analysis. In
addition, it was selected for a refined multipathway assessment in the
supplemental proposal. These three PB-HAP were cadmium, Hg, and PAHs.
Even though neither facility exceeded the Tier II screening levels for
cadmium, Eramet had the higher value. Eramet also emits dioxins, but
the other facility had a higher exceedance of its Tier II screening
level. The refined analysis was conducted on all four PB-HAP using
updated emissions as described above. The refined analysis for this
facility showed that the Tier II screen for each pollutant over-
predicted the potential risk when compared to the refined analysis
results.
    Overall, the refined analysis predicts a potential lifetime cancer
risk of 20-in-1 million to the maximum most exposed individual due to
exposure to dioxins and PAHs. The non-cancer HQ is predicted to be
below 1 for cadmium compounds and 1 for Hg compounds. These results,
based on updated emissions, are very similar to those presented in the
supplemental proposal.
    Further details on the refined multipathway analysis can be found
in Appendix 10 of the Residual Risk Assessment for the Ferroalloys
Production Source Category in Support of the 2015 Final Rule, which is
available in the docket.
    e. Environmental Risk Screening Results. As described in section
III.A of the supplemental proposal preamble (79 FR 60238), we conducted
an environmental risk screening assessment for the Ferroalloys
Production source category. In the Tier I screening analysis for PB-HAP
(other than lead, which was evaluated differently as noted in section
III.A of the supplemental proposal preamble, 79 FR 60238), the
individual modeled Tier I concentrations for one facility in the source
category exceeded some sediment, fish-avian piscivorus, and surface
soil benchmarks for PAHs, methylmercury, and mercuric chloride.
Therefore, we conducted a Tier II assessment.
    In the Tier II screening analysis for PAHs and methylmercury, none
of the individual modeled concentrations for any facility in the source
category exceeded any of the ecological benchmarks (either the lowest-
observed-adverse-effect level or the no-observed-adverse-effect level).
For mercuric chloride, soil benchmarks were exceeded for some
individual modeled points that collectively accounted for 11 percent of
the modeled area. However, the weighted average modeled concentration
for all soil parcels was well below the soil benchmarks. For

lead, we did not estimate any exceedances of the secondary lead
National Ambient Air Quality Standards (NAAQS).
    For HCl, each individual concentration (i.e., each off-site data
point in the modeling domain) was below the ecological benchmarks for
all facilities. The average modeled HCl concentration around each
facility (i.e., the average concentration of all off-site data points
in the modeling domain) did not exceed any ecological benchmark. For
HF, some individual modeled points exceeded the ecological benchmark
but accounted for less than 0.02 percent of the modeled area. The
average modeled HF concentration around each facility (i.e., the
average concentration of all off-site data points in the modeling
domain) did not exceed any ecological benchmarks. These results, based
on updated emissions, are very similar to those presented in the
supplemental proposal.
    f. Facility-Wide Risk Assessment Results. As in the supplemental
proposal, for both facilities in this source category, there are no
other HAP emissions sources present beyond those included in the source
category. Therefore, we conclude that the facility-wide risk is the
same as the source category risk and that no separate facility-wide
analysis is necessary.
    g. Demographic Analysis Results. To examine the potential for any
environmental justice (EJ) issues that might be associated with the
source category, we updated the demographic analysis that was conducted
for the supplemental proposal, using the risk results based on the
updated emissions. A demographic analysis 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 noncancer hazards from the Ferroalloys
Production source category across different social, demographic, and
economic groups within the populations living near facilities
identified as having the highest risks. The methodology and the results
of the demographic analyses are included in a technical report, Risk
and Technology Review--Analysis of Socio-Economic Factors for
Populations Living Near Ferroalloys Facilities, which is available in
the docket for this action.
    The results of the demographic analysis are summarized in Table 4
below. These results, for various demographic groups, are based on the
estimated risks from actual emissions levels for the population living
within 50 kilometers (km) of the facilities.

              Table 4--Ferroalloys Production Demographic Risk Analysis Results for 2015 Final Rule
----------------------------------------------------------------------------------------------------------------
                                                                             Population with
                                                                            cancer risk at or   Population with
                                                                               above 1-in-1      chronic hazard
                                                             Nationwide       million due to   index above 1 due
                                                                               Ferroalloys       to Ferroalloys
                                                                                Production         Production
----------------------------------------------------------------------------------------------------------------
Total Population.......................................        312,861,265             40,748              1,348
----------------------------------------------------------------------------------------------------------------
                                                 Race by Percent
----------------------------------------------------------------------------------------------------------------
White..................................................                 72                 97                 99
All Other Races........................................                 28                  3                  1
----------------------------------------------------------------------------------------------------------------
                                                 Race by Percent
----------------------------------------------------------------------------------------------------------------
White..................................................                 72                 97                 99
African American.......................................                 13                  1                  0
Native American........................................                  1                  0                  0
Other and Multiracial..................................                 14                  2                  1
----------------------------------------------------------------------------------------------------------------
                                              Ethnicity by Percent
----------------------------------------------------------------------------------------------------------------
Hispanic...............................................                 17                  1                  1
Non-Hispanic...........................................                 83                 99                 99
----------------------------------------------------------------------------------------------------------------
                                                Income by Percent
----------------------------------------------------------------------------------------------------------------
Below Poverty Level....................................                 14                 15                  6
Above Poverty Level....................................                 86                 85                 94
----------------------------------------------------------------------------------------------------------------
                                              Education by Percent
----------------------------------------------------------------------------------------------------------------
Over 25 and without High School Diploma................                 15                 11                 10
Over 25 and with a High School Diploma.................                 85                 89                 90
----------------------------------------------------------------------------------------------------------------
                                                 Age by Percent
----------------------------------------------------------------------------------------------------------------
Ages 0 to 17...........................................                 24                 21                 22
Ages 18 to 64..........................................                 63                 61                 59
Ages 65 and up.........................................                 13                 18                 19
----------------------------------------------------------------------------------------------------------------

    The results of the Ferroalloys Production source category
demographic analysis indicate that emissions from the source category
expose approximately 41,000 people to a cancer risk at or above 1-in-1
million and approximately 1,300 people to a chronic non-cancer TOSHI
greater than 1 (we note that many of those in the first risk group are
the same as those in the second). The percentages of the at-risk
population in each demographic group

(except for ages 65 and up) are similar to or lower than their
respective nationwide percentages. These results are very similar to
those presented in the supplemental proposal.
3. What key comments did we receive on the risk review, and what are
our responses?
    Several comments were received regarding the risk assessment for
the Ferroalloys Production source category. The following is a summary
of some of the more significant 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 Pollutant Emissions: Ferroalloys Production Summary of
Public Comments and the EPA's Responses on Proposed Rule (76 FR 72508,
November 23, 2011) and Supplemental Proposal (79 FR 60238, October 6,
2014), which is available in the docket for this action (EPA-HQ-OAR-
2010-0895).
    Comment: Several comments were received on the reference value used
in the risk assessment to evaluate chronic noncancer effects due to
exposure to manganese. In the 2011 proposal, we used the Integrated
Risk Information System (IRIS) reference concentration (RfC), and we
received negative comments regarding that value not being the ``best
available science.'' We evaluated the available values and, in
accordance with our prioritized dose-response values and Scientific
Advisory Board (SAB) comments, we used the Agency for Toxic Substances
and Disease Registry (ATSDR) minimum risk level (MRL) for manganese in
the risk assessment for the 2014 supplemental proposal. We received
mixed comments in response to the supplemental proposal. Some comments
were negative regarding our use of the ATSDR MRL, while others were
generally supportive of our use of the MRL compared to the IRIS value,
yet still thought the MRL was not the appropriate reference value to
use in the assessment.
    Regarding use of the IRIS RfC for manganese in the 2011 proposal
risk assessment, commenters stated that the manganese RfC was outdated,
did not constitute the best available science (including use of
benchmark dose statistical analyses or physiologically-based
pharmacokinetic models), and substantial research has been conducted
since the 1993 IRIS RfC was last updated. The commenters refer to their
own calculations and studies and developed their own reference value
for manganese and state that the EPA should use that value. Regarding
use of the ATSDR MRL for manganese in the 2014 supplemental proposal
risk assessment, the same commenters stated that the manganese MRL was
an improvement over the IRIS RfC, but was still not the best available
science because, in their review, ATSDR did not apply physiologically-
based pharmacokinetic models. The commenters again refer to their own
calculations and studies developing a reference value for manganese and
state that EPA should use that value. Another commenter disagrees with
the use of the ATSDR MRL because the EPA has not provided sufficient
rationale for using a less-protective value. Instead, this commenter
recommended that we continue to use the IRIS RfC value.
    Response: We agree that there were newer information and
assessments available at the time of the 2011 proposal and also for the
2014 supplemental proposal, some of which may use the currently
preferred approach for developing dose-response values (i.e., the
benchmark dose approach). However, we only use reference values which
meet certain criteria in regards to how they are derived (using EPA
guidelines or similar), derived by credible sources with health-
protective goals similar to those of the EPA, using peer-review
procedures also similar to the level applied to the EPA values, and
with an open public comment process. We have a tiered priority list for
sources of chronic dose-response information, which meet these criteria
(as described in the supplemental proposal, 79 FR 60238). The tiered
prioritized list has been through a SAB review and was favorably
received.
    In the risk assessment for the 2011 proposal, we used the IRIS RfC
for chronic exposure to manganese and received numerous comments
regarding use of that value. In response to those comments, we
considered the existing peer-reviewed health effect reference values
for chronic inhalation exposure to manganese from other federal, state,
and international agencies and organizations. We developed a reference
value array document \2\ providing additional details for the available
values. We noted that the ATSDR MRL value available for the 2011
proposal was a draft value. The ATSDR MRL was subsequently finalized in
2012.
---------------------------------------------------------------------------

    \2\ U.S. EPA. Mn and BTEX Reference Value Arrays (Final
Reports). U.S. Environmental Protection Agency, Washington, DC, EPA/
600/R-12/047F, 2013.
---------------------------------------------------------------------------

    In our consideration of available reference values, we did not
include some values specifically noted in public comments. The level of
peer review for non-governmental scientific publications is
qualitatively different than the governmental processes used to derive
the values described in our tiered prioritized list, and some of the
values in the manganese reference value array document. The information
provided by these additional references from the commenter(s) may prove
useful in an IRIS reassessment for manganese, and we agree that the
physiologically-based models, along with all other relevant available
peer-reviewed literature, will be considered in any IRIS reassessment
of manganese. Yet, a direct application of any of these values instead
of an established value in our tiered list of prioritized dose-response
values would be inconsistent with the EPA policy as implemented in the
RTR Program, and with recommendations from the SAB.
    After considering the values in our tiered list of prioritized
dose-response values, and consistent with Agency policy supported by
SAB, we decided to rely on the 2012 ATSDR MRL value for the 2014
supplemental proposal. Both the 1993 IRIS RfC and the 2012 ATSDR MRL
were based on the same study (Roels et al., 1993). In developing their
assessment, ATSDR used updated dose-response modeling methodology
(benchmark dose approach) and considered recent pharmacokinetic
findings to support their selection of uncertainty values in the MRL
derivation.
4. What is the rationale for our final approach and final decisions for
the risk review?
    As noted in section II.A.1 of this preamble, the EPA sets standards
under CAA section 112(f)(2) using ``a two-step standard-setting
approach, with an analytical first step to determine an `acceptable
risk' that considers all health information, including risk estimation
uncertainty and includes a presumptive limit on maximum individual
lifetime risk (MIR) of approximately 1 in 10 thousand.'' \3\ (54 FR
38045, September 14, 1989).
---------------------------------------------------------------------------

    \3\ 1-in-10 thousand is equivalent to 100-in-1 million. The EPA
currently describes cancer risks as `n-in-1 million.'
---------------------------------------------------------------------------

    a. Acceptability Determination. As in the supplemental proposal,
the EPA concludes that the risks are unacceptable for the following
reasons. First, the EPA considered the fact that the noncancer hazard
HQ ranges from 4 based on actual emissions to 40 based on allowable
emissions. The EPA has not established under section 112 of the CAA a
numerical range for risk

acceptability for noncancer effects as it has with carcinogens, nor has
it determined that there is a bright line above which acceptability is
denied. However, the Agency has established that, as exposure increases
above a reference level (as indicated by a HQ or TOSHI greater than 1),
confidence that the public will not experience adverse health effects
decreases and the likelihood that an effect will occur increases. For
the Ferroalloys Production source category, the potential for members
of the public to be exposed to manganese at concentrations up to 40
times the MRL reduces the Agency's confidence that the public is
protected from adverse health effects and diminished the Agency's
ability to determine that such exposures are acceptable. Second, the
EPA considered the fact that the cancer risk estimate for actual
emissions is 20-in-1 million and up to 100-in-1 million for allowable
emissions. While 20-in-1 million is well within the acceptable range,
risks from allowable emissions are at the upper end of the range of
acceptability. This fact, combined with the fact that the noncancer
hazard is up to 40 times the MRL and the refined multipathway HQ for Hg
is at the RfD, leads the Agency to conclude that the risk from this
source category is unacceptable.
    b. What is EPA requiring in the final rule to address the
unacceptable risks? As mentioned above, to address the unacceptable
risks, we are promulgating tighter PM emission limits for the stacks,
which significantly reduces risks due to allowable emissions.
Furthermore, to reduce risks due to process fugitive emissions, we are
promulgating a requirement that facilities must achieve effective
enhanced capture of process fugitive emissions using a system of
primary hoods (that capture process fugitive emissions near the source)
and/or secondary capture of fugitives (which would capture remaining
fugitive emissions near the roof-line). Facilities must install,
operate, and maintain a process fugitives capture system that is
designed to capture and control 95 percent or more of the process
fugitive emissions. We are also promulgating an opacity limit of 8
percent to ensure process fugitive emissions are effectively captured
and controlled. Facilities will need to meet an average opacity of 8
percent for the entire furnace cycle (about 90-120 minutes) with a
maximum opacity of no more than 20-percent opacity for any 12-minute
period. Moreover, facilities will need to monitor various control
parameters (such as fan speed, amperage, pressure drops, and/or damper
positioning) to ensure the process fugitive capture systems and
controls are working properly.
    c. Remaining Risks After Implementation of the Requirements to
Address Unacceptable Risks. To determine the remaining risks after
implementation of the lower stack PM emissions limits and requirements
to effectively control process fugitives (described above), we
conducted a post control risk assessment, which is described in detail
in the document titled Residual Risk Assessment for the Ferroalloys
Source Category in Support of the 2015 Final Rule, which is available
in the docket for this rulemaking.
    Based on this post control risk assessment, we conclude that after
the requirements described above to address unacceptable risks are
implemented, the risks to public health will be substantially reduced.
    For example, the results of the post-control chronic inhalation
cancer risk assessment indicate that the maximum individual lifetime
cancer risk posed by these two facilities, after the implementation of
the promulgated controls, will be no higher than 10-in-1 million, with
an estimated reduction in cancer incidence to 0.002 cases per year. In
addition, the number of people estimated to have a cancer risk greater
than or equal to 1-in-1 million would be 26,000. The results of the
post-control risk assessment also indicate that the maximum chronic
noncancer inhalation TOSHI value would be reduced to 1. The number of
people estimated to have a TOSHI greater than 1 would be reduced to 0.
We also estimate that after the implementation of controls, the maximum
worst-case acute HQ value would be less than 1 (based on REL values).
    Considering post-control emissions of multipathway HAP, Hg
emissions would be reduced by approximately 3 pounds per year (lbs/yr),
lead would be reduced by about 1,600 lbs/yr, polycyclic organic matter
(POM) emissions would be reduced by approximately 3,600 lbs/yr, cadmium
would be reduced by about 150 lbs/yr, and dioxins and furans would be
reduced by about 0.002 lbs/yr from the baseline emission rates.
    d. Ample Margin of Safety Analysis. Under the ample margin of
safety analysis, we again considered all of the health factors
evaluated in the acceptability determination and evaluated the cost and
feasibility of available control technologies and other measures
(including the controls, measures, and costs reviewed under the
technology review) that could be applied in this source category to
further reduce the risks due to emissions of HAP identified in our risk
assessment.
    As described above, we estimate that the actions finalized under
CAA section 112(f)(2) to address unacceptable risks will reduce the MIR
to 10-in-1 million. The cancer incidence will be reduced to 0.002 cases
per year and the number of people estimated to have cancer risks
greater than 1-in-1 million will be reduced to 26,000 people. The
chronic noncancer inhalation TOSHI will be reduced to 1 and the number
of people exposed to a TOSHI level greater than 1 will be reduced to 0.
In addition, the potential multipathway impacts will be reduced.
    Based on all of the above information, we conclude that the risks
will be acceptable after implementation of the lower stack limits for
PM and the control requirements to reduce process fugitive emissions,
as we concluded in the supplemental proposal. Based on our research and
analysis, we did not identify any cost-effective controls beyond those
described above that would achieve further reduction in risk. While in
theory, the 2011 proposed approach of total enclosure with negative
pressure would provide some additional risk reduction, the additional
risk reduction is minimal and, similar to our assessment and
conclusions described in the supplemental proposal, we continue to
believe the total enclosure approach would not be economically feasible
and may not be technically feasible for these facilities. No other
technology advances were identified during the comment period.
Therefore, we are not promulgating any additional requirements under
the ample margin of safety analysis beyond the requirements being
finalized to address unacceptable risks (as described above). We
conclude that the controls to achieve acceptable risks will also
provide an ample margin of safety to protect public health.

B. Technology Review for the Ferroalloys Production Source Category

1. What did we propose pursuant to CAA section 112(d)(6) for the
Ferroalloys Production source category?
    Pursuant to CAA section 112(d)(6), we conducted a technology
review, which focused on identifying and evaluating developments in
practices, processes, and control technologies for the emission sources
in the Ferroalloys Production source category. For the 2011 proposal
(76 FR 72508), we

identified developments in practices, processes or control technologies
for PM emissions from stacks (as a surrogate for metal HAP) and for
process fugitive metal HAP emissions. Based on the comments received
from the public and information received through a 2012 ICR, we revised
both the technology review and risk assessment for the Ferroalloys
Production source category, which were described in detail in the 2014
supplemental proposal (79 FR 60238).
    a. PM Emission Limits From Stacks. For PM stack emissions limits,
we determined for the 2011 proposal that the test data received from
the two facilities indicate that all five furnaces that are in
operation have PM emission levels that are well below their respective
emission limits in the 1999 MACT rule, which were based on size and
product being produced. The test data received from the facilities also
indicate that the PM emission levels for MOR and crushing and sizing
are well below their respective emission limits in the 1999 MACT rule.
These findings demonstrate that add-on particulate control technologies
(Venturi scrubber, positive pressure fabric filter, negative pressure
fabric filter) used to control emissions from the sources are effective
in reducing PM (used as a surrogate for metal HAP). Based on these
findings, in 2011 we proposed a PM limit of 24 mg/dscm corrected to 2
percent carbon dioxide (CO2) for existing furnaces.
    We received additional test data after the 2011 proposal and re-
evaluated the PM limit using available PM emissions test data and
consideration of variability across these data. Based on this analysis,
we determined that it was appropriate to propose a revised PM limit of
25 mg/dscm for existing furnaces. No additional add-on control is
expected to be required by the facilities to meet this revised existing
source limit. To demonstrate compliance, we proposed these sources
would be required to conduct periodic performance testing and develop
and operate according to a baghouse operating plan or continuously
monitor Venturi scrubber operating parameters. We also proposed that
furnace baghouses would be required to be equipped with bag leak
detection systems (BLDS).
    For the 2011 proposal, the proposed new source PM standard was
determined by evaluating the available data from the best performing
furnace (which was determined to be furnace #2 at Felman). The proposed
new source limit was determined to be 9.3 mg/dscm. We received
additional test data after the 2011 proposal and re-evaluated the new
source limit using the available test data. The revised new source PM
standard for furnaces for the 2014 supplemental proposal was determined
by evaluating the available data from the best performing furnace
(which was again determined to be furnace #2 at Felman). The new source
MACT limit was determined to be 4.0 mg/dscm based on data from furnace
#2 and was proposed as the MACT emissions limit for PM from new and
reconstructed source furnace stacks in the 2014 supplemental proposal.
    The PM emission limit for the local ventilation control device
outlet was also re-evaluated using compliance test data and test data
from the 2012 ICR. A local ventilation control system is used to
capture tapping, casting, or ladle treatment emissions and direct them
to a control device other than one associated with the furnace. The
2011 proposal included a proposed PM limit for the local ventilation
control device that was based on PM data from the furnaces. After the
2011 proposal, we received test data from three different emissions
tests (for a total of nine test runs) specifically for this local
ventilation source. We determined these data were more appropriate for
the development of a limit for this source than the furnace data we had
used for the 2011 proposal. There is currently only one local
ventilation control device outlet emissions source in this source
category. Using the new data for the one existing local ventilation
source, we calculated a revised emissions limit of 4.0 mg/dscm and
determined that this was an appropriate emissions limit for this
source. Therefore, we proposed an emissions limit of 4.0 mg/dscm for
existing, new, and reconstructed local ventilation control device
emissions sources in the supplemental proposal.
    For crushing and screening operations, we proposed an emission
limit of 13 mg/dscm for new and existing crushing and sizing operations
in the 2011 proposal. We did not receive any additional data for this
emission source and, therefore, made no revisions to this proposed
limit in the 2014 supplemental proposal.
    The MOR operation is a unique process that is operated by only one
facility (Eramet). We calculated a proposed emission limit of 3.9 mg/
dscm in the 2011 proposal that would apply to both new and existing MOR
operation sources. We did not receive any additional data for this
emission source and, therefore, made no revisions to this proposed
limit in the 2014 supplemental proposal.
    b. Emission Standards for Process Fugitives. For process fugitive
metal HAP emissions, we identified two potential developments in
practices and control techniques. One option would require facilities
to install and operate enhanced capture of process fugitive emissions
using a combination of primary hoods and ductwork in close proximity to
the emission sources, such as tapping or casting and/or secondary hoods
located near the roofline. Another option would be to require full
enclosure of the furnace building(s) with negative pressure and
evacuate the process fugitive emissions to a control device(s). In the
2011 proposal, we proposed that the full furnace building enclosure
option represented an advance in emission control measures since the
Ferroalloys Production NESHAP was originally promulgated in 1999.
    For day-to-day continuous monitoring to demonstrate compliance with
the proposed full building enclosure requirements, the 2011 proposal
relied mainly on requiring monitoring differential pressure to ensure
facilities maintained a negative pressure of at least 0.007 inches of
water and that emissions within the facilities would need to be vented
to PM control devices. This was to be supplemented by operation and
work practice standards that required preparation of a process fugitive
emissions ventilation plan for each shop building. In the 2011
proposal, we also proposed a requirement that emissions exiting from a
shop building may not exceed more than 10-percent opacity for more than
one 6-minute period, to be demonstrated every 5 years as part of the
periodic required performance tests.
    We received significant comments in response to the 2011 proposal.
Commenters claimed that we had significantly underestimated the costs
for full building enclosure and that it would not be feasible for these
facilities. After reviewing and considering the comments along with
other information, we decided to re-evaluate the proposed requirement
for negative pressure ventilation and consider other options.
    Based on our re-evaluation, for the 2014 supplemental proposal, we
concluded that the full-building enclosure option may not be feasible
and would have significant economic impacts on the facilities. However,
we concluded that an option based on enhanced local capture and control
of process fugitive emissions using a combination of primary and
secondary hoods is a feasible and cost-effective approach to achieve
significant reductions in process fugitive HAP emissions. Therefore, in
the 2014 supplemental proposal, we proposed

that facilities would need to install and operate a local capture
system using a combination of primary and/or secondary hoods that is
designed to achieve at least 95-percent capture and control of process
fugitive emissions.
    With the move to the proposed enhanced local capture alternative in
the 2014 supplemental proposal, we no longer had a day-to-day
continuous requirement of monitoring negative pressure. Instead, in the
2014 supplemental proposal, continuous compliance demonstration would
be based mainly on meeting an opacity limit, monitoring ventilation
parameters (such as fan speed, amperage, and/or damper positioning),
and documenting the design of the system to achieve 95-percent capture.
Since opacity monitoring would be a primary method to demonstrate
continuous compliance, we proposed that facilities would need to meet
an average opacity of 8 percent for an entire furnace cycle (about 90-
120 minutes) with a maximum opacity of no more than 20 percent opacity
for any 12-minute period. Furthermore, we proposed facilities would
need to monitor opacity for a full furnace cycle (about 90-120 minutes)
at least once per week per furnace building. We also proposed that, if
the average opacity reading from the shop building is greater than 8-
percent opacity during an observed furnace process cycle, an additional
two more furnace process cycles must be observed such that the average
opacity during the entire observation period is less than 7-percent
opacity. A furnace process cycle means the period in which the furnace
is tapped to the time in which the furnace is tapped again and includes
periods of charging, smelting, tapping, casting, and ladle raking.
    Regarding the design requirements, in the supplemental proposal, we
proposed that the facilities in this source category must install,
operate, and maintain a process fugitives capture system that is
designed to collect 95 percent or more of the process fugitive
emissions from furnace operations, casting MOR process, ladle raking,
and slag skimming and crushing and screening operations and convey the
collected emissions to a control device that meets specified emission
limits and the proposed opacity limits. We proposed that this plan be
submitted to the permitting authority, incorporated into the source's
operating permit and updated every 5 years or when there is a
significant change in variables that affect process fugitive emissions
ventilation design. We proposed that this list of design criteria,
coupled with the requirement for frequent opacity observations and
operating parameter monitoring, would ensure process fugitive emissions
are effectively controlled and would result in enforceable
requirements.
    More information concerning our proposed technology review can be
found in the memoranda titled, Revised Technology Review for the
Ferroalloys Production Source Category, and Cost Impacts of Control
Options Considered for the Ferroalloys Production NESHAP to Address
Fugitive HAP Emissions, which are available in the docket, and in the
preamble to the 2014 supplemental proposed rule, 79 FR at 60271 to
60273.
2. How did the technology review change for the Ferroalloys Production
source category?
    For the October 6, 2014, supplemental proposal, we solicited
comment regarding the use of new technologies to provide continuous or
near continuous long term approaches to monitoring emissions from
industrial sources for the Ferroalloy Production source category. After
considering comments received and after evaluating the technologies
further, we are replacing the weekly Method 9 opacity requirement with
a weekly requirement to measure opacity using ASTM D7520-13 and DCOT to
demonstrate compliance with the process fugitives standards. The final
rule amendments require facilities to use the DCOT to measure opacity
at least once per week for each of the furnace and MOR buildings to
demonstrate compliance with the opacity limits. However, as mentioned
above, facilities will have the opportunity to reduce the frequency of
opacity readings to monthly after 26 consecutive weeks of compliant
weekly readings. The facilities would still be required to meet an
average opacity standard of 8-percent opacity for the furnace cycle
(90-120 minutes) and at no time during operation may any two
consecutive 6-minute block opacity readings be greater than 20-percent
opacity. The cost of implementing the DCOT system is estimated to be
approximately $200,000 per year for the source category with weekly
readings. However, these costs decrease to about $90,000 per year for
the source category if they do monthly readings per furnace building.
All other requirements we proposed under CAA section 112(d)(6) in the
supplemental proposal have not changed.
3. What key comments did we receive on the technology review, and what
are our responses?
    Several comments were received regarding the technology review for
the Ferroalloys Production source category. The following is a summary
of the more significant 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 Pollutant Emissions: Ferroalloys Production Summary of Public
Comments and the EPA's Responses on Proposed Rule (76 FR 72508,
November 23, 2011) and Supplemental Proposal (79 FR 60238, October 6,
2014), which is available in the docket for this action (EPA-HQ-OAR-
2010-0895).
    Comment: One commenter supported the EPA's decision to re-evaluate
the feasibility and cost-effectiveness of the controls that the Agency
proposed in its 2011 proposal. However, the commenter objects to the
EPA's conclusion that an alternative system involving both primary and
secondary capture is available and represents an ``advancement in
technology'' pursuant to CAA section 112(d)(6). The commenter states
that this type of system does not currently exist in practice at any
ferroalloy operation. They explain that, in theory, such a system
appears likely to provide some degree of additional reductions.
However, the commenter notes some of the specific potential control
methods mentioned by the EPA have already been proven not to work. As
an example, the commenter states that curtains have previously been
installed in an attempt to contain additional furnace emissions, but
the curtains burned up due to the extreme heat in only a few weeks. The
commenter, therefore, objects both to the characterization of these
additional controls as a currently available ``advancement in
technology,'' and to the EPA's conclusion that the cost of almost
$100,000 per ton of HAP reductions for these additional controls is
cost effective.
    Response: In their supplemental comments on the 2011 proposed rule,
industry representatives provided suggested alternative designs to
address fugitive emissions from the furnace buildings. The designs
suggested by the industry representatives included improving the
existing primary hooding and capture systems close to the emissions
sources and/or adding secondary capture to ensure effective capture and
control of process fugitive

emissions. The use of a primary hooding and exhaust system in
conjunction with general secondary hooding and exhaust system was
estimated to provide a total capture of 95 percent of process fugitive
emissions, including emissions from the tapping, casting, crushing/
screening, and skimming/slag raking processes.
    We reviewed these designs and discussed the designs with
ventilation experts. The ventilation experts agreed that the suggested
primary system along with secondary capture could achieve 95 percent
reduction of process fugitive emissions from the buildings. They noted
that many of the designs and improvements were based on the elements of
good ventilation systems that are used in other industries to capture
and control fugitive emissions. Because these designs have been only
partially deployed in this industry, they constitute a relevant
development in technology beyond what is required by the current rule.
We view the successful deployment of these technologies in other
industries and the expert judgement of industrial ventilation experts
as establishing that the technologies are technically available for
transfer to the Ferroalloy Production source category.
    As part of our technology review, we evaluated the costs and
effectiveness of a regulatory option that is based on the general
emission control scenario suggested by the industry representatives
which would include a system of primary and/or secondary hooding
designed to capture 95 percent of process fugitive emissions. The
process fugitive emissions would be captured by the primary and/or
secondary hoods and routed to PM control devices. This option for the
control of process fugitive emissions under CAA section 112(d)(6) is
exactly the same option that we are promulgating under CAA section
112(f)(2) to capture and control fugitives (described in section IV.A
of this preamble). We estimate that the total capital cost including
monitoring would be about $40.3 million, the total annualized costs
would be about $7.7 million per year, and that it would achieve 77 tpy
reduction of HAP, mostly manganese and other HAP metals (e.g., cadmium
compounds, chromium compounds, nickel compounds) and also achieve about
229 tpy reduction of PM. Based on our evaluation, we conclude that
installing and operating such a system is a feasible and cost-effective
approach to achieve significant reductions in process fugitive HAP
emissions and will achieve almost as much reductions as the full
building enclosure option (229 vs. 252 tons PM reductions). In light of
the technical feasibility and cost effectiveness of this enhanced
fugitive capture option (that includes a combination of primary capture
and/or secondary capture designed to capture and control 95 percent of
process fugitive), we are promulgating this option under the authority
of section 112(d)(6) of the CAA. The control requirements and
compliance requirements under this CAA section 112(d)(6) option are the
exact same requirements we are promulgating under CAA section 112(f)(2)
to address unacceptable risks for process fugitive emissions (described
in section IV.A of this preamble). As described in that section,
facilities must install, operate, and maintain a process fugitives
capture system that is designed to capture 95 percent or more of the
process fugitive emissions. Facilities will also need to meet an
average opacity of 8 percent for each furnace cycle (about 90-120
minutes) with a maximum opacity of no more than 20 percent opacity for
any two consecutive 6-minute block opacity readings (12-minute period).
To demonstrate compliance, facilities will need to initially monitor
opacity for a full furnace cycle (about 90-120 minutes) at least once
per week per furnace building using the DCOT. Moreover, facilities will
need to monitor various control parameters (such as fan speed,
amperage, pressure drops, and/or damper positioning) to ensure the
fugitive capture system and controls are working properly.
    Comment: One commenter states that the only notable development
that occurred in ferroalloys emission practices, processes, and control
technologies since the 1999 NESHAP took effect is the installation of
scrubbers and baghouses. Since scrubbers and baghouses have
demonstrably different performance in controlling particulate
emissions, the commenter claims that developments since 1999 warrant
separate particulate emission limits based on the type of control
device involved. The commenter states that the EPA did not acknowledge
this development and proposed a single stack particulate limit for all
furnaces. The commenter provided proposed PM limits of 27 mg/dscm for
wet particulate scrubbers and 6.2 mg/dscm for baghouses, and notes that
these limits would actually reduce the total allowable particulate
emissions from their facility in comparison to the EPA's proposed
single limit of 25 mg/dscm.
    Response: Section 112 of the CAA grants the EPA discretion to
establish ``categories and subcategories'' of sources to be regulated
under CAA section 112, and further allows the EPA to ``distinguish
among classes, types and sizes of sources within a category or
subcategory'' when establishing MACT standards. However, we believe it
is not appropriate to establish subcategories based on type of control
technology used by these emission sources.
    In the case of the PM emissions from the ferroalloy furnaces, we
believe if it was appropriate, we could subcategorize based on the size
of the furnace or the product being produced in that furnace. However,
we determined that there was no statistical difference in PM emissions
based on the size of the individual furnaces or by the product being
produced in those furnaces. Therefore, we decided it was not
appropriate to subcategorize for PM emissions and instead established a
single PM limit for all of the furnaces, regardless of size or product
being produced.
    Comment: One commenter believes that the EPA's proposed
requirements to reduce process fugitive emissions under CAA section
112(d)(6) are not based on control practices in use in the ferroalloys
industry, but rather simply reflect a decision by the EPA that the
sources at Eramet and Felman should be subject to additional
requirements. By putting the enhanced fugitive control requirements
under CAA section 112(d)(6), the commenter believes that the EPA
dispenses with any attempt to justify the requirements as cost
effective, as would be required to impose for ``beyond the MACT floor''
standards under CAA section 112(d)(2), and the EPA dispenses with any
attempt to present a risk-based justification for the requirements, as
would be required under CAA section 112(f)(2).
    Response: As an initial matter, we note the process fugitive
control requirements are justified as risk-based requirements under CAA
section 112(f)(2). See section IV.A of this preamble. Therefore, the
premise of this comment is factually incorrect. That said, the
requirements of this rule also are justified under CAA section
112(d)(6). Under CAA section 112(d)(6), we are required to review
emission standards no less frequently than every 8 years and revise
them ``as necessary (taking into account developments in practices,
processes, and control technologies).'' The ferroalloys industry
already includes some of the controls envisioned under this control
scenario. For example, all 5 furnaces in the source category in the
U.S. already have some type of primary hooding to capture some process
fugitive emissions from tapping and/or casting operations. In fact, one
of the five furnaces in the U.S. already achieves good capture of

tapping emissions with their current configuration. Furthermore,
effective primary and secondary capture systems are currently used in
other metals industries (e.g., steel production, secondary lead
production) to effectively capture and control process fugitives.
    Moreover, as described above, representatives from the ferroalloys
companies have provided suggestions as to how such a system could be
designed, installed and operated to achieve 95-percent capture of
fugitives. Therefore, we conclude such a system is technically
feasible. Furthermore, as we described above, we conclude these
controls would be cost effective ($91,000 per ton of HAP metal
reduced). Therefore, we conclude it is appropriate to promulgate this
control option under section 112(d)(6) of the CAA.
4. What is the rationale for our final approach for the technology
review?
    a. PM Emissions Limits from Stacks. The available test data from
the five furnaces located at the two facilities indicate that all of
these furnaces have PM emission levels that are well below their
respective emission limits in the 1999 MACT rule. These findings
demonstrate that the add-on emission control technologies (Venturi
scrubber, positive pressure fabric filter, negative pressure fabric
filter) used to control emissions from the furnaces are effective in
reducing particulate matter (used as a surrogate for metal HAP).
    The PM emissions, used as a surrogate for metal HAP, that were
reported by the industry in response to the 2010 ICR, were far below
the level specified in the current NESHAP, indicating improvements in
the control of PM emissions since promulgation of the current NESHAP.
We re-evaluated the data received in 2010, along with additional data
received in 2012 and 2013, to determine whether it is appropriate to
promulgate revised emissions limits for PM from the furnace process
vents. More details regarding the available PM data and this re-
evaluation are provided in the Revised Technology Review for the
Ferroalloys Production Source Category for the Supplemental Proposal,
which is available in the docket. Unlike PAH and Hg stack data, we did
not see significant differences in emissions based on product produced
(e.g., FeMn or SiMn). Therefore, we are not promulgating separate PM
stack limits based on product type.
    Based on this analysis, we determined it is appropriate to finalize
the revised existing source furnace stack PM emissions limit of 25 mg/
dscm, which is the same limit we proposed in the supplemental proposal.
No additional add-on controls are expected to be required by the
facilities to meet the revised existing source limit of 25 mg/dscm.
However, this revised limit will result in significantly lower
``allowable'' PM emissions from the source category compared to the
level of emissions allowed by the 1999 MACT rule and would help prevent
any emissions increases. To demonstrate compliance, these sources will
be required to conduct periodic performance testing and develop and
operate according to a baghouse operating plan or continuously monitor
Venturi scrubber operating parameters. Also furnace baghouses will be
required to be equipped with BLDS.
    The final PM standard for new and reconstructed furnaces is 4.0 mg/
dscm and was determined by evaluating the available data from the best
performing furnace (which was determined to be furnace #2 at Felman).
    As described above, the PM emission limit for the local ventilation
control device outlet was re-evaluated for the supplemental proposal
using compliance test data and test data from the 2012 ICR. We did not
receive any additional data since the supplemental proposal for this
source. Using all the available data for the one existing local
ventilation source, we calculated an emissions limit of 4.0 mg/dscm,
which is the exact same limit we proposed in the supplemental proposal.
We conclude that this is still an appropriate emissions limit for this
source. Therefore, we are promulgating this emissions limit of 4.0 mg/
dscm for existing, new, and reconstructed local ventilation control
device emissions sources. In addition, we are promulgating a PM limit
of 3.9 mg/dscm for any new, reconstructed, or existing MOR process, and
a PM limit of 13 mg/dscm for any new, reconstructed, or existing
crushing and screening equipment, which are consistent with what we
proposed in our November 23, 2011, proposal.
    Furthermore, as mentioned in section III of this preamble, we are
promulgating a PM limit of 3.9 mg/dscm for any new, reconstructed, or
existing MOR process, and a PM limit of 13 mg/dscm for any new,
reconstructed, or existing crushing and screening equipment.
2. Standards for Process Fugitive Metal HAP Emissions
    In the 2011 proposal, we proposed a requirement for sources to
enclose the furnace building, collect fugitive emissions such that the
furnace building is maintained under negative pressure, and duct those
emissions to control devices. As described above, commenters on the
2011 proposal disagreed with our assessment.
    Commenters also raised concerns about worker safety and comfort in
designing and operating full enclosure systems. We believe that such
issues can be overcome with proper ventilation design and installation
of air conditioning systems and other steps to ensure these issues are
not a problem. However, after further review and evaluation, we
conclude that it would be quite costly for these facilities to become
fully enclosed with negative pressure and achieve the appropriate
ventilation and conditioning of indoor air.
    We re-evaluated the costs and operational feasibility associated
with the full building enclosure with negative pressure. We consulted
with ventilation experts who have worked with hot process fugitives
similar to those found in the ferroalloys industry (e.g., electric arc
furnace steel mini-mills and secondary lead smelters). We determined
that substantially more air flow, air exchanges, ductwork, fans and
control devices and supporting structural improvements would be needed
(compared to what we had estimated in the 2011 proposal) to achieve
negative pressure and also ensure adequate ventilation and air quality
in these large furnace buildings. Therefore, as explained in the
supplemental proposal, we determined that the proposed negative
pressure approach presented in the 2011 proposal would be much more
expensive than what we had estimated in 2011 and may not be feasible
for these facilities.
    As mentioned above, for the supplemental proposal, we also
evaluated another option based on enhanced capture of the process
fugitive emissions using a combination of effective local capture with
primary hooding close to the emissions sources and/or secondary capture
of remaining fugitives with roof-line capture hoods and control
devices. These buildings are currently designed such that fugitive
emissions that are not captured by the primary hoods flow upward with a
natural draft to the open roof vents and are vented to the atmosphere
uncontrolled. Under our enhanced control scenario, the primary capture
close to the emissions sources would be significantly improved with
effective local hooding and ventilation and the remaining fugitive
emissions (that are not captured by the primary hoods) would be drawn
up to the roof-line and

captured with secondary hooding and vented to control devices.
    In cases where additional collection of fugitives from the roof
areas is needed to comply with the rule, fume collection areas may be
isolated via baffles (so the area above the furnace where fumes collect
may be kept separated from ``empty'' spaces in large buildings) and
roof openings over fume collection areas can be sealed and fumes
directed to control devices. The fugitive emission capture system
should achieve inflow at the building floor, but outflow toward the
roof where most of the remaining fugitives would be captured by the
secondary hooding. We concluded that a rigorous, systematic examination
of the ventilation requirements throughout the building is the key to
developing a fugitive emission capture system (consisting of primary
hoods, secondary hoods, enclosures, and/or building ventilation ducted
to PM control devices) that can be designed and operated to achieve
very low levels of fugitive emissions. Such an evaluation considers
worker health, safety, and comfort and it is designed to optimize
existing ventilation options (fan capacity and hood design). Thus, we
concluded that an enhanced capture system based on these design
principles does represent an advancement in technology. We estimate
that this type of control system could capture 95 percent of the
process fugitive emissions and vent those emissions to PM control
devices. This enhanced local capture option is described in more detail
in the Revised Technology Review for the Ferroalloys Production Source
Category and in the Cost Impacts of Control Options to Address Fugitive
HAP Emissions for the Ferroalloys Production NESHAP Supplemental
Proposal documents, which are available in the docket.
    Under this control option, the cost elements vary by plant and
furnace and include the following:
     Curtains or doors surrounding furnace tops to contain
fugitive emissions;
     Improvements to hoods collecting tapping emissions;
     Upgrade fans to improve the airflow of fabric filters
controlling fugitive emissions;
     Addition of ``secondary capture'' or additional hoods to
capture emissions from tapping platforms or crucibles;
     Addition of fugitives capture for casting operations;
     Improvement of existing control devices or addition of
fabric filters; and
     Addition of rooftop ventilation, in which fugitive
emissions escaping local capture are collected in the roof canopy over
process areas through addition of partitions, hoods, and then directed
through ducts to control devices.
    We estimate the total capital costs of installing the required
ductwork, fans and control devices under the enhanced capture option
(which is described above and in more detail in the Cost Impacts of
Control Options to Address Fugitive HAP Emissions for the Ferroalloys
Production NESHAP Supplemental Proposal document) to be $40.3 million
and the total annualized cost to be $7.7 million for the two plants.
The total estimated HAP reduction for the enhanced capture option is 77
tpy at a cost per ton of $103,000 ($52 per pound). We also estimate
that this option would achieve PM emission reductions of 229 tpy,
resulting in cost per ton of PM removed of $34,600 per ton and achieve
particulate matter 2.5 microns and less (PM2.5) emission
reductions of 48 tons per year, resulting in a cost per ton of
PM2.5 removal of $165,000 per ton. We believe these controls
for process fugitive HAP emissions (described above), which are based
on enhanced capture (with primary and secondary hooding) are feasible
for the Ferroalloys Production source category from a technical
standpoint and are cost effective. These cost effectivenesses are in
the range of cost effectiveness for PM and HAP metals from other
previous rules. However, it is important to note that there is no
bright line for determining acceptable cost effectiveness for HAP
metals. Each rulemaking is different and various factors must be
considered. Some of the other factors we consider when making decisions
whether to establish standards beyond-the-floor (BTF) under CAA section
112(d)(2) or under CAA section 112(d)(6) include, but are not limited
to, the following: which of the HAP metals are being reduced and by how
much; total capital costs; annual costs; and costs compared to total
revenues (e.g., costs to revenue ratios).
    As described in the supplemental proposal, we also re-evaluated the
option based on full building enclosure with negative pressure.
    Based on those analyses, we concluded in the supplemental proposal
and conclude again in this action that the full-building enclosure
option with negative pressure may not be feasible and would have
significant economic impacts on the facilities (including potential
closure for one or more facilities). Therefore, we are not promulgating
an option based on full building enclosure with negative pressure.
    However, consistent with the supplemental proposal, we conclude
that the enhanced local capture option is a feasible and cost-effective
approach to achieve significant reductions in fugitive HAP emissions
and will achieve almost as much reductions as the full-building
enclosure option (229 vs. 252 tons PM reductions) and, thus, achieving
most of the emission reductions at significantly lower costs. In light
of the technical feasibility and cost effectiveness of the enhanced
capture option, we are promulgating the enhanced capture option under
the authority of section 112(d)(6) of the CAA.
    Regarding monitoring requirements, as described above, in the 2011
proposal, we proposed that facilities would need to conduct day-to-day
continuous monitoring of differential pressure to comply with the
proposed full building enclosure with negative pressure requirements.
    With the move to the enhanced local capture alternative option,
there is no longer any requirement to monitor negative pressure. Under
this option, the main ongoing compliance requirements will be based on
opacity readings and parametric monitoring. Therefore, since opacity is
a main method of monitoring compliance for process fugitive emissions
controls, we believe that frequent opacity monitoring is necessary, as
reflected in the supplemental proposal. Furthermore, as we explained in
the supplemental proposal, we believe an average opacity limit of 8
percent is appropriate to ensure effective capture and control of
process fugitive emissions over the entire furnace cycles and that a
maximum opacity of 20 percent for any 2 consecutive 6-minute periods is
appropriate to prevent spikes in fugitive emissions. Therefore, we are
promulgating an average opacity limit of 8 percent and a maximum
opacity limit of 20 percent for any 2 consecutive 6-minute periods.
    Regarding opacity monitoring, we are promulgating a requirement
that facilities conduct opacity observations at least once per week for
a full furnace cycle for each operating furnace and each MOR operation
using the DCOT instead of Method 9. We believe the DCOT is appropriate
for the final rule because it provides more objective and better
substantiated opacity readings. However, as described above, we are
allowing an opportunity for facilities to decrease frequency of opacity
monitoring to monthly after 26 compliant weekly readings.
    Similar to the supplemental proposal, we are also finalizing the
requirement

that, if the average opacity reading from the shop building is greater
than 8-percent opacity during an observed furnace process cycle, an
additional two more furnace process cycles must be observed such that
the average opacity during the entire observation period is less than
7-percent opacity. A furnace process cycle means the period in which
the furnace is tapped to the time in which the furnace is tapped again
and includes periods of charging, smelting, tapping, casting, and ladle
raking.
    As mentioned above, we are also promulgating the requirement that
at no time during operation may any two consecutive 6-minute block
opacity readings be greater than 20-percent opacity.
    We believe that the source should demonstrate that the overall
design of the ventilation system is adequate to achieve the final
standards. Therefore, we are promulgating the requirement that
facilities in this source category must install, operate, and maintain
a process fugitives capture system that is designed to collect 95
percent or more of the process fugitive emissions from furnace
operations, casting MOR process, ladle raking and slag skimming and
crushing, and screening operations, and convey the collected emissions
to a control device that meets specified emission limits and the
opacity limits. We are also requiring continuous monitoring of key
ventilation operating system parameters and periodic inspections of the
ventilation systems to ensure that the ventilation systems are
operating as designed.
    We believe that if the facilities design the capture and control
systems according to the most recent (at the time of construction)
ventilation design principles recommended by the American Conference of
Governmental Industrial Hygienists (ACGIH), including detailed
schematics of the ventilation system design, addressing variables that
affect capture efficiency such as cross drafts and describes protocol
or design characteristics to minimize such events and identifies
monitoring and maintenance steps, the plan will be capable of ensuring
the system is properly designed and continues to operate as designed.
Therefore, we are promulgating the requirement that facilities develop
such a plan and submit this plan to the permitting authority. The plan
must also be incorporated into the source's operating permit and
updated every 5 years or when there is a significant change in
variables that affect process fugitive emissions ventilation design.
This design plan, coupled with the requirement for frequent opacity
observations and operating parameter monitoring, will ensure fugitive
emissions are effectively controlled and will result in enforceable
requirements. We recognize that other design requirements and/or more
frequent opacity observations may yield more compliance certainty, but
incur greater costs and not result in measurable decreases in
emissions.
    We believe the additional PM data we received justifies the revised
PM stack emission limits we are promulgating under the authority of
section 112(d)(6) of the CAA. We also believe the enhanced capture and
control is a development in technology that is feasible and cost
effective, so we are promulgating the enhanced local capture and
control option under the authority of section 112(d)(6) of the CAA.
Furthermore, we believe it is appropriate to promulgate the DCOT to
ensure adequate furnace capture and control.

C. CAA Section 112(d)(2) & (3) Revisions for the Ferroalloys Production
Source Category

1. What did we propose pursuant to CAA section 112(d)(2) & (3) for the
Ferroalloys Production source category?
    In the November 23, 2011, proposal, we proposed a formaldehyde
emission limit of 201 [mu]g/dscm for any new, reconstructed, or
existing electric arc furnace.
    In the October 6, 2014, supplemental proposal, we proposed the
following:
     HCL emission limit of 180 [mu]g/dscm for new or
reconstructed electric arc furnaces and 1,100 [mu]g/dscm for existing
electric arc furnaces;
     Hg emission limit of 17 [mu]g/dscm for new or
reconstructed electric arc furnaces producing FeMn, and 170 [mu]g/dscm
for existing electric arc furnaces producing FeMn;
     Hg emission limit of 4 [mu]g/dscm for new or reconstructed
electric arc furnaces producing SiMn and 12 [mu]g/dscm for existing
electric arc furnaces producing SiMn;
     PAH emission limit of 880 mu;g/dscm for new or
reconstructed electric arc furnaces producing FeMn and 1,400 [mu]g/dscm
for existing electric arc furnaces producing FeMn; and
     PAH emission limit of 72 [mu]g/dscm for new or
reconstructed electric arc furnaces producing SiMn and 120 [mu]g/dscm
for existing electric arc furnaces producing SiMn.
2. How did the CAA section 112(d)(2) & (3) revisions change for the
Ferroalloys Production source category?
    In mid-August 2014, a few weeks prior to the signature of the
supplemental proposal, we received a test report with Hg and PAH data,
which we were unable to incorporate into the proposed limits in the
supplemental proposal, in part because of the timing and in part
because we had not completed our review and technical analysis of the
data. We noted receipt of the data and invited comment on it in the
supplemental proposal, and made the data available for review. We
committed to considering these data in the final rule based on public
comment and our technical analysis. In addition to the pre-supplemental
proposal data, another Hg and PAH test report was received during the
comment period. The new test data for FeMn production received in
August 2014 and during the comment period had much higher PAH
concentrations than the data that were previously provided. The new PAH
test data for SiMn production were only slightly higher than previous
data received from the facilities. The new Hg data for both FeMn and
SiMn production were comparable to the test data that we used to
develop the proposed limits for the supplemental proposal.
    For this action, we re-evaluated the PAH and Hg emission limits to
include the new test data. The 99-percent upper prediction limit (UPL)
calculation using all the available reliable data for PAH emissions
results in an emissions limit of 12,000 [mu]g/dscm for existing
furnaces producing FeMn and 130 [mu]g/dscm for existing furnaces
producing SiMn.
    With regard to new source limits, as mentioned previously, there
are only two furnaces in the source category that produce FeMn, and
both furnaces are located at Eramet. The units are similar in design
and process the same types of raw materials, and we, therefore, expect
little or no difference in the performance of these units. The
available emissions data, which show that the two units mean emissions
are only 2-percent different, support this hypothesis. We conclude,
based on the similarities in the units and the available data, that
these two furnaces achieve the same degree of control of PAH emissions
with their current control devices. Accordingly, we consider these two
units to be equal performers with regard to PAH emissions and
therefore, we used all the data from both units to calculate the new
source emissions limit. Using the 99-percent UPL calculation, we derive

an emissions limit of 11,500 [mu]g/dscm for new furnaces producing
FeMn.