[Federal Register Volume 84, Number 48 (Tuesday, March 12, 2019)]
[Rules and Regulations]
[Pages 8813-8820]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-04389]
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ENVIRONMENTAL PROTECTION AGENCY
40 CFR Part 52
[EPA-R09-OAR-2017-0621; FRL-9990-40-Region 9]
Approval and Promulgation of Air Quality Implementation Plans;
Arizona; Nonattainment Plan for the Miami SO2 Nonattainment Area
AGENCY: Environmental Protection Agency (EPA).
ACTION: Final rule.
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SUMMARY: The Environmental Protection Agency (EPA) is approving an
Arizona state implementation plan (SIP) revision for attaining the 2010
1-hour sulfur dioxide (SO2) primary national ambient air
quality standard (NAAQS or ``standard'') for the Miami, Arizona
SO2 nonattainment area (NAA). This SIP revision (hereinafter
called the ``Miami SO2 Plan'' or ``Plan'') includes
Arizona's attainment demonstration and other elements required under
the Clean Air Act (CAA or ``Act''). In addition to an attainment
demonstration, the Plan addresses the requirements for meeting
reasonable further progress toward attainment of the NAAQS, reasonably
available control measures and reasonably available control technology,
base-year and projected emission inventories, enforceable emissions
limitations and control measures, and contingency measures. The EPA
concludes that the Plan provides for attainment of the 2010 1-hour
primary SO2 NAAQS in the Miami SO2 NAA by the
attainment date of October 4, 2018, and meets the other applicable
requirements under the CAA.
DATES: This final rule is effective on April 11, 2019.
ADDRESSES: The EPA has established a docket for this action under
Docket ID No. EPA-R09-OAR-2017-0621. All documents in the docket are
listed on the https://www.regulations.gov website. Although listed in
the index, some information is not publicly available, e.g.,
Confidential Business Information (CBI) or other information
[[Page 8814]]
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 through https://www.regulations.gov.
FOR FURTHER INFORMATION CONTACT: Krishna Viswanathan, EPA, Region IX,
Air Division, Air Planning Office, (520) 999-7880 or
[email protected].
SUPPLEMENTARY INFORMATION: Throughout this document whenever, ``we,''
``us,'' or ``our'' is used, we mean the EPA.
Table of Contents
I. Background
II. Public Comments and Response to Comments
III. The EPA's Final Action
IV. Statutory and Executive Order Reviews
I. Background
On June 22, 2010, the EPA promulgated a new 1-hour primary
SO2 NAAQS of 75 parts per billion (ppb) (hereinafter called
``the 2010 SO2 NAAQS'' or ``the SO2 NAAQS'').
This standard is met at an ambient air quality monitoring site when the
3-year average of the annual 99th percentile of daily maximum 1-hour
average concentrations does not exceed 75 ppb, as determined in
accordance with appendix T of 40 CFR part 50.\1\ On August 5, 2013, the
EPA designated 29 areas of the country as nonattainment for the 2010
SO2 NAAQS, including the Miami SO2 NAA within
Arizona.\2\ These area designations became effective on October 4,
2013. Section 191 of the CAA directs states to submit SIP revisions for
areas designated as nonattainment for the SO2 NAAQS to the
EPA within 18 months of the effective date of the designation, i.e., in
this case by no later than April 4, 2015. Under CAA section 192, these
SIP submissions are required to include measures that will bring the
nonattainment area into attainment of the NAAQS as expeditiously as
practicable, but no later than five years from the effective date of
designation. The attainment date for the Miami SO2 NAA was
October 4, 2018.
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\1\ 75 FR 35520, codified at 40 CFR 50.17(a)-(b).
\2\ 78 FR 47191, codified at 40 CFR part 81, subpart C.
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Nonattainment plans for SO2 must meet sections 110, 172,
191 and 192 of the CAA. The EPA's regulations governing nonattainment
SIP submissions are set forth at 40 CFR part 51, with specific
procedural requirements and control strategy requirements residing at
subparts F and G, respectively. Soon after Congress enacted the 1990
Amendments to the CAA, the EPA issued comprehensive guidance on SIP
revisions in the ``General Preamble for the Implementation of Title I
of the Clean Air Act Amendments of 1990'' (``General Preamble'').\3\
Among other things, the General Preamble addressed SO2 SIP
submissions and fundamental principles for SIP control strategies.\4\
On April 23, 2014, the EPA issued guidance for meeting the statutory
requirements in SO2 SIP submissions in a document entitled,
``Guidance for 1-Hour SO2 Nonattainment Area SIP
Submissions'' (``2014 SO2 Guidance'').\5\ In the 2014
SO2 Guidance, the EPA described the statutory requirements
for a complete nonattainment plan, which include: An accurate emissions
inventory of current emissions for all sources of SO2 within
the NAA; an attainment demonstration; demonstration of reasonable
further progress (RFP); implementation of reasonably available control
measures (RACM) (including reasonably available control technology
(RACT)); new source review; enforceable emissions limitations and
control measures; conformity; and adequate contingency measures for the
affected area.
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\3\ 57 FR 13498 (April 16, 1992).
\4\ Id. at 13545-49, 13567-68.
\5\ Guidance for 1-Hour SO2 Nonattainment Area SIP
Submissions, April 23, 2014.
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For the EPA to fully approve a SIP revision as meeting the
requirements of CAA sections 110, 172, and 191-192 and the EPA's
regulations at 40 CFR part 51, the plan for the affected area needs to
demonstrate that each of the aforementioned requirements has been met.
Under CAA section 110(l), the EPA may not approve a plan that would
interfere with any applicable requirement concerning NAAQS attainment
and RFP, or any other applicable requirement. Under CAA section 193, no
requirement in effect (or required to be adopted by an order,
settlement, agreement, or plan in effect before November 15, 1990) in
any area that is a NAA for any air pollutant may be modified in any
manner unless it ensures equivalent or greater emission reductions of
such air pollutant.
The EPA published a notice on March 18, 2016, finding that Arizona
and other states had failed to submit the required SO2
nonattainment plans for the Miami SO2 NAA and several other
areas by the submittal deadline.\6\ This finding, which became
effective on April 18, 2016, initiated a deadline under CAA section
179(a) for the potential imposition of new source review offset and
highway funding sanctions. Additionally, under CAA section 110(c), the
finding triggered a requirement that the EPA promulgate a federal
implementation plan (FIP) within two years of the effective date of the
finding unless the State has submitted, and the EPA has approved, the
nonattainment plan as meeting applicable requirements.
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\6\ 81 FR 14736.
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In response to the EPA's finding, the Arizona Department of
Environmental Quality (ADEQ) submitted the Miami SO2 Plan on
March 9, 2017, and submitted associated final rules on April 6,
2017.\7\ The EPA issued letters dated July 17, 2017, and September 26,
2017, finding the submittals complete and halting the sanctions clock
under CAA section 179(a).\8\ Today's final SIP approval terminates the
EPA's duty to promulgate a FIP for the area.
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\7\ Letters dated March 8, 2017, and April 6, 2017, from Tim
Franquist, Director, Air Quality Division, ADEQ, to Alexis Strauss,
Acting Regional Administrator, EPA Region IX. Although the cover
letter for the Miami SO2 Plan was dated March 8, 2017,
the Plan was transmitted to the EPA on March 9, 2017.
\8\ Letters dated July 17, 2017, and September 26, 2017, from
Elizabeth Adams, Acting Air Division Director, EPA Region IX, to Tim
Franquist, Director, Air Quality Division, ADEQ.
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II. Public Comments and Response to Comments
The EPA proposed to approve the Miami SO2 Plan on June
15, 2018.\9\ As part of this action, we also proposed to approve the
use of AERMOD v14134 and BLP (``BLP/AERMOD Hybrid Approach'') as an
alternative model to represent emissions from the roofline of the Miami
Smelter (``smelter'').\10\ The EPA's proposed action provided a 30-day
public comment period. During this period, we received eight comment
letters. Six of these comment letters raised issues that are outside of
the scope of this rulemaking, including air quality in China, India,
and other areas of the United States, wind power, and relations between
the United States and Russia. We are not required to respond to these
comments and are not doing so here. Two comment letters, one from the
Arizona Mining Association (AMA) and one from the National Parks
Conservation Association (NPCA), the Sierra Club (SC), and Arizona
Mining Reform Coalition (AMRC) (collectively, ``the Non-Governmental
Organizations'' or ``NGOs'') raised issues germane to this
action.11 12 The EPA's summary of
[[Page 8815]]
germane comments and responses are provided below. All comments
received on the proposal are included in the docket for this action.
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\9\ 83 FR 27938, June 15, 2018.
\10\ Id. at 27942.
\11\ Letter dated July 16, 2018, from Steve Trussell, Executive
Director, Arizona Mining Association, to Michael Stoker, Regional
Administrator, EPA Region IX.
\12\ Letter dated July 16, 2018, from Kevin Dahl, NPCA, Sandy
Bahr, SC, and Roger Featherstone, AMRC, to Krishna Viswanathan, Air
Division, EPA Region IX.
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A. Comments From the AMA
Comment: The AMA expressed support for our proposed approval of the
Miami SO2 SIP. In addition, the commenter specifically
requested clarification of the following statement from our proposal:
The EPA also acknowledges the concern that longer-term emission
limits can allow short periods with emissions above the critical
emissions value, which, if coincident with meteorological conditions
conducive to high SO2 concentrations, could in turn
create the possibility of a NAAQS exceedance occurring on a day when
an exceedance would not have occurred if emissions were continuously
controlled at the level corresponding to the critical emission
value.
The AMA requested that the EPA ``revise this discussion to make it
clear that the evaluation of the longer-term limit is looking at
whether additional hourly exceedances of the numeric portion of the
NAAQS will occur rather than NAAQS exceedances.''
Response: We note AMA's support for our proposed approval. With
respect to the commenter's request for clarification, the commenter
appears to be confusing the term ``NAAQS exceedance'' with ``NAAQS
violation.'' The hourly exceedance of the level of a NAAQS is the same
as a NAAQS exceedance as used in our proposal but is different from a
NAAQS violation. As explained in our proposal:
As specified in 40 CFR 50.17(b), the 1-hour primary
SO2 NAAQS is met at an ambient air quality monitoring
site when the 3-year average of the annual 99th percentile of daily
maximum 1-hour average concentrations is less than or equal to 75
ppb. In a year with 365 days of valid monitoring data, the 99th
percentile would be the fourth highest daily maximum 1-hour value. .
. Because the standard has this form, a single hourly exceedance
does not create a violation of the standard.\13\
\13\ 83 FR 27940, June 15, 2018 (emphasis added).
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To restate, when we use the term ``NAAQS exceedance'' (both in our
proposal and in this document), we refer to an hourly exceedance of the
75 ppb level, rather than to a NAAQS violation, which would occur only
when the 3-year average of the annual 99th percentile of daily maximum
1-hour average concentrations is greater than 75 ppb.
B. Comments From the NGOs
Comment: The NGOs noted that Arizona was subject to a March 18,
2016 ``Finding of Failure to Submit,'' and the EPA was therefore
obligated to approve the SIP or promulgate a FIP if the SIP was not
approved by April 18, 2018. They asserted that the SIP was not approved
nor was a FIP in place by the deadline.
Response: We acknowledge that the EPA did not approve a SIP
revision or promulgate a FIP for the Miami SO2 NAA by April
18, 2018, as required under CAA 110(c)(1)(A). However, with this final
action to approve the Miami SO2 Plan, we are discharging our
statutory obligation under CAA section 110(k)(2) to act on the SIP, and
such approval terminates our FIP obligation under section 110(c)(1)(A)
for the Miami SO2 NAA.
Comment: The NGOs stated that the Miami, Arizona area had a design
value of 105 ppb when designated nonattainment; whereas the 2014-2016
design value was 200 ppb, and the 2015-2017 preliminary design value
was 221 ppb. The commenters asserted that, because attainment is
determined by averaging over three years, the area will remain in
nonattainment on the October 4, 2018 attainment deadline even if
readings were 0.0 ppb from this point forward. On this basis they
concluded that, even though the control measures may be operational by
October 4, 2018, the State has already failed to demonstrate attainment
by the statutory deadline.
Response: We disagree with this comment. We note that, contrary to
the commenters' suggestion, the CAA does not require states with
SO2 nonattainment areas to factually ``demonstrate
attainment by the statutory deadline'' in the SIPs they submit
containing the control measures that will achieve attainment. Rather,
sections 172 and 192 of the CAA require states to submit SIP revisions
that ``provide for attainment'' of the SO2 NAAQS by the
attainment date. In our proposal, we described our interpretation of
``provide for attainment'' and the rationale for finding that the Miami
SO2 plan submitted by the State of Arizona does provide for
attainment.\14\ In particular, Arizona's submittal provides modeling-
based evidence that establishes that the control measures required on
the single source of emissions in the area are sufficient to yield air
quality that attains the NAAQS by the attainment deadline.
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\14\ 83 FR 27947, June 15, 2018.
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The available monitoring data should not be interpreted as
indicating that Arizona's SIP has failed to provide for timely
attainment. The monitoring data cited by the commenter were collected
before the full implementation of the measures in the Miami
SO2 plan, which occurred in 2018.\15\ Therefore, these data
are indicative of whether air quality met the standard prior to full
implementation of the measures reflected in the modeling demonstration,
but these data are not a reliable indicator of whether air quality,
after implementation of all modeled relevant control measures, would be
expected to meet the standard at the attainment deadline. In other
words, these data are not indicative of the adequacy of the plan and
its modeling demonstration to provide for NAAQS attainment. Instead, as
the EPA explained in our 2014 SO2 Guidance and in numerous
proposed and final SIP notices implementing the SO2 NAAQS, a
key element of an approvable SIP is the required modeling demonstration
showing that the remedial control measures and strategy are adequate to
bring a previously or currently violating area into attainment. Given
the form of the 2010 NAAQS as the 3-year average of the 99th percentile
of the yearly distribution of 1-hour daily maximum SO2
concentrations, it is often possible that the three-year period of
monitored data will not reflect the actual air quality levels resulting
from implementation of the newer remedial control measures implemented
within that period. In such cases, as it is here, the more complete and
representative analysis for informing action on a submitted SIP should
focus on the results of newly implemented control measures required
under the plan, rather than historical concentrations that do not
reflect the results of the plan's required control measures. The former
analysis explicitly addresses whether air quality will be attaining (as
required) under the state's submitted plan, whereas the latter analysis
may have little to no bearing on what will happen as a result of the
plan. Therefore, in the context of reviewing the adequacy of those
newer control measures to provide for newly attaining air quality under
sections 172 and 192, we conclude that it is reasonable to focus on the
modeling results that specifically account for those control measures
and the resulting reductions
[[Page 8816]]
in SO2 emissions, rather than on monitored data that, in
this case, do not represent air quality levels resulting from full
implementation of the control measures in the Plan. In the Miami
SO2 Plan, Arizona's modeling shows that implementation of
the measures included in the Plan result in air quality that attains
the NAAQS.
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\15\ On December 19, 2017, FMMI notified the EPA and ADEQ that
it had completed construction of the SO2 capture and
control system upgrades and had initiated associated commissioning
activities. Letter from Byron Belew, FMMI, to Alexis Strauss, EPA,
and Timothy Franquist, ADEQ (December 19, 2017).
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Under the CAA, a determination of whether an area has failed to
attain is a separate action from the review of an attainment
demonstration SIP. The EPA's SIP review occurs under CAA sections
110(k), 172(c) and 192(a), while a determination of whether an
SO2 NAA has failed to attain is governed by CAA section
179(c)(1). Under section 110(k)(3), the EPA is required to approve a
SIP submission that meets all applicable requirements of the CAA. For
the reasons described in our proposal and elsewhere in this notice, we
have concluded that the Miami SO2 Plan meets all such
requirements, including the requirement in 172(c) and 192(a) to provide
for attainment by the attainment date. This is the determination that
is the subject of today's final SIP approval action.
Separately, in a different action under section 179(c)(1) that is
beyond the scope of today's final SIP approval action, the EPA must
determine within six months of the attainment date whether an area has
attained the NAAQS based on the area's air quality as of the attainment
date. Accordingly, the EPA will in a separate action, analyze the
pertinent information and determine whether the Miami SO2
NAA attained the NAAQS by the attainment date in accordance with
section 179(c)(1).
In response to the part of the comment related to change in ambient
values, we note that the 2009-2011 design value used to designate the
NAA was based on SO2 data from the Miami Ridgeline monitor,
which was the only SO2 monitor in the NAA at that time. The
2015-2017 design value cited by the commenter was based on data from
the Miami Jones Ranch Monitor, which was installed in 2013. Because of
safety and infrastructure concerns, the Ridgeline monitor ceased
operation on September 26, 2017, following EPA approval of the site's
closure.\16\ As shown in Table 1, during the years that both the
Ridgeline and Jones Ranch monitors had valid design values (2015 and
2016), the design values for the Jones Ranch monitor were more than 50
ppb higher than the design values for the Miami Ridgeline monitor. The
change in design value noted by the commenters reflects the more recent
design value information provided by the Miami Jones Ranch monitor and
appears to be more the result of monitoring at a different location
rather than a significant worsening of air quality as implied by the
commenter. Again, however, the EPA is not taking any final action today
under CAA section 179(c) to determine whether the Miami area factually
attained the NAAQS by the attainment date, and our discussion of the
monitoring data from the Ridgeline and the Jones ranch monitors
presented here is for informational purposes only.
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\16\ Letter dated September 19, 2017, from Elizabeth Adams,
Acting Director, Air Division EPA Region IX, to Timothy Franquist,
Director, Air Quality, ADEQ.
Table 1--2010 1-hr SO2 NAAQS Design Values for Monitors in the Miami SO2 NAA (ppb)
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Site name AQS ID 2011 2012 2013 2014 2015 2016 2017
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Ridgeline \1\................................ 04-007-0009 111 107 105 122 145 146 N/A
Jones Ranch \2\.............................. 04-007-0011 N/A N/A N/A N/A 199 200 221
Townsite \3\................................. 04-007-0012 N/A N/A N/A N/A 196 194 159
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N/A = not available.
\1\ The Ridgeline monitor ceased operation on September 26, 2017, due to safety and infrastructure concerns.
\2\ The Jones Ranch monitor became operational on February 1, 2013.
\3\ The Townsite monitor site became operational on February 1, 2013.
Comment: The commenters noted that the EPA stated that it agreed
with the State's placement of modeling receptors, which relied on an
ambient air boundary consisting of the facility's physical fence line
as well as several boundary segments with no fence that the State
inspected and concluded steep topography precludes public access.
However, the commenters asserted that ``there is no EPA regulation or
written policy stating that steep topography is not ambient air.
Impacts in these areas should not be ignored in the modeling
simulations, and thus, the State has not demonstrated that the proposed
emission limit of 142.45 lb/hr provides for attainment of the
SO2 NAAQS.''
Response: Ambient air is defined as ``that portion of the
atmosphere, external to buildings, to which the general public has
access.'' \17\ The 2014 SO2 Guidance, Appendix A, Section
5.2 states ``[t]he model receptor grid is unique to the particular
situation and depends on the size of the modeling domain, the number of
modeled sources, and complexity of the terrain. Receptors should be
placed in areas that are considered ambient air (i.e., where the public
generally has access) relative to a particular facility. . . .'' The
EPA policy on excluding areas from ambient air has been stated in a
series of letters and memoranda. In a 1980 letter from Administrator
Douglas Costle to Senator Jennings Randolph,\18\ the EPA stated its
policy that the exclusion from ambient air is available only for the
atmosphere over land owned or controlled by the source and to which
public access is precluded by a fence or other physical barriers, based
on a case-by-case review of individual situations to ensure that the
public is adequately protected. This represents the EPA's current
policy with regard to ambient air. As part of a demonstration that an
exclusion is appropriate, a source should take steps to preclude the
general public from accessing the property by relying on some type of
physical barrier, such as a fence, wall, or a natural obstruction.\19\
As a result, we disagree with the commenter's assertion that the EPA
lacks a written policy that allows for steep topography to preclude
public access to facility property. As described above, a natural
obstruction, such as steep topography, may be considered to be part of
an ambient air boundary, consistent with the regulatory definition of
ambient air, if it is effective in
[[Page 8817]]
precluding the general public from accessing the property and can be a
basis for excluding such area for receptor placement in the modeling.
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\17\ 40 CFR 50.1(e).
\18\ Letter dated December 19, 1980, from Douglas M. Costle,
Administrator, EPA to Senator Jennings Randolph, Chairman,
Environment and Public Works Committee.
\19\ Memorandum dated June 22, 2007, from Stephen D. Page,
Director, Office of Air Quality Planning & Standards, EPA to
Regional Air Division Directors, ``Interpretation of `Ambient Air'
In Situations Involving Leased Land Under the Regulations for
Prevention of Significant Deterioration.'' As indicated in the
attachment to this EPA memo at footnote 1, ``preclude'' does not
necessarily imply that public access is absolutely impossible, but
rather that the likelihood of such access is small.
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We note that the EPA is currently evaluating this ambient air
policy to consider whether access to property by the general public may
be effectively precluded or deterred, consistent with the existing
regulatory definition of ambient air, by means other than a fence or
other physical barriers.\20\ Such a revision to our policy would not
alter our finding that Arizona properly excluded receptors in areas
owned or controlled by the source where steep topography precludes
public access.
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\20\ EPA Draft Guidance dated November 2018, ``Revised Policy on
Exclusions from `Ambient Air.' '' https://www.epa.gov/nsr/forms/draft-guidance-revised-policy-exclusions-ambient-air.
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Comment: The NGOs commented that according to the spreadsheet from
the docket \21\ Freeport-McMoRan Miami Incorporated's (FMMI's) existing
permit requires individual limits, on a pound per hour (lb/hr) basis,
on the various SO 2 emitting processes. They asserted that
our proposed action does not include a discussion as to why it is
appropriate to now switch to a single facility-wide limit with a longer
term (i.e., 30-day averaging basis).
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\21\ See C.4 2015-07-13 FMMI Emissions Inventory--2015-07-13--
Past Actuals Using Sulfur Balance.
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Response: First, we disagree with the commenter's characterization
of ``switching'' from individual limits to a facility-wide limit, as it
implies that these existing limits will either be replaced or cease to
be applicable following the approval of the Miami SO2 Plan.
The permit limits listed in the spreadsheet cited by the commenter are
found in Attachment C of FMMI's title V permit.\22\ The limits are
820.00 lb/hr for the Acid Plant Tail Gas Stack, 312.00 lb/hr for the
Vent Fume Stack, and 1288 lb/hr for all fugitives.\23\ These existing
limits were established under separate legal authority to meet separate
regulatory requirements and will not be altered by the addition of the
142.45 lb/hr limit (30-day rolling average) that applies to the entire
facility under Arizona Administrative Code, Title 18, Chapter 2,
Article 13, Section R18-2-C1302 (``Rule C1302'').\24\
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\22\ The spreadsheet cited by the commenter (i.e., ``C.4 2015-
07-13 FMMI--Emissions Inventory--2015-07-13--Past Actuals Using
Sulfur Balance'') refers to Title V Permit 53592, which was issued
on November 26, 2012, and expired on November 25, 2017. FMMI's
current Title V Permit 66039, which was issued on December 20, 2019,
includes the same emissions limits in Attachment C as Title V Permit
53592.
\23\ Title Permit 66039, Attachment C.
\24\ The EPA approved Rule C1302 into the Arizona SIP at 83 FR
56736 (November 14, 2018).
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Second, we note that these existing individual limits were not in
the SIP and were not intended to provide for attainment of the NAAQS.
The appropriateness of the facility-wide, 30-day rolling emission limit
for attainment of the NAAQS must be evaluated based upon the legal
requirements and guidance associated with implementation of the 1-hr
SO2 NAAQS. Contrary to the commenter's assertion, our
proposal did explain why it is appropriate to use both a facility-wide
limit and a longer-term limit in this case.\25\ As explained in the
proposal, the State provided an analysis to show that due to the batch
nature of the smelting process at the Miami Smelter, the emissions from
the various units (``sources'') at the facility are independent of one
another and therefore do not peak at the same time. The collection of
future maximum potential SO2 emission rates for each source
represents a conservative estimate of the worst-case emission
distribution at the smelter. Additionally, ADEQ submitted an analysis
that demonstrates that variations in the location of peak emissions
among sources will not affect attainment, and a facility-wide emissions
limit is sufficiently protective.
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\25\ 83 FR 27938, June 15, 2018.
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Comment: The commenters asserted that the adjustment factor used to
develop the emission limit for the Miami Smelter (0.37) indicates that
its operation is much more variable than are emissions at electric
generating units (EGUs) and that the EPA's 2014 SO2 Guidance
was developed based on empirical evidence to assess the variability of
the operation of EGUs, not sulfuric acid plants. They argued that this
greater variability means that there is much higher probability that
any given hour is above the critical emission value (CEV) for this
sulfuric acid plant relative to the EGUs cited in the 2014
SO2 Guidance. They asserted that there was no discussion of
the estimated percentage of time that the hourly emissions are expected
to be above the CEV and that the EPA or the State, at a minimum, should
provide some discussion on expected emissions and assess the
variability in terms of sulfuric acid plants rather than EGUs.
Response: We agree that emissions at the Miami Smelter are more
variable than for EGUs. The adjustment factor for the Miami Smelter was
0.37 compared to the national average adjustment factors (i.e., 0.63-
0.79) estimated for EGUs and listed in Table 1 of Appendix D of the
2014 SO2 Guidance. The approach outlined in the 2014
SO2 Guidance accounts for whatever degree of variability a
source has, because the adjustment factor is designed to reflect the
source's own emission distribution and variability. The higher degree
of adjustment for the Miami Smelter compared to the EGUs means that the
longer-term emission limit for the smelter is lowered further to ensure
that hourly emissions exceeding the CEV are a rare occurrence. Indeed,
the protocol given in the 2014 SO2 Guidance is designed to
provide for long-term average emission levels above the long-term
average limit to be as rare as 1-hour emission levels above the CEV,
which for the Miami Smelter necessitates more adjustment than is
necessary for most EGUs. Therefore, we disagree with the commenters
that this increased variability means there is a higher probability
that any given hour is above the CEV compared to the sources envisioned
by the 2014 SO2 Guidance. As described in our proposal, the
State used hourly SO2 data collected using continuous
emission monitors from May 2013 to October 2014, adjusted to account
for Miami Smelter's upgrades and increased production capacity, as a
representative emission distribution for the smelter's future
configuration.\26\ Appendix C to the Miami SO2 Plan,
''Modeling Technical Support Document for the Miami Sulfur Dioxide
(SO2) Nonattainment Area'' (``Modeling TSD''), Table 8-7
specifies this representative emission distribution includes 60 hours
above the CEV, which amounts to 0.5 percent of operating hours. The
EPA's 2014 SO2 Guidance states that ``if above the critical
emission value are a rare occurrence at a source, these periods would
be unlikely to have a significant impact on air quality, insofar as
they would be very unlikely to occur repeatedly at the times when the
meteorology is conducive for high ambient concentrations of
SO2.'' \27\ We conclude that the limit for the Miami
Smelter, which we expect to result in no more than 0.5 percent of hours
exceeding the CEV, qualifies as assuring that such occasions of
elevated emissions will be sufficiently rare to provide for attainment,
consistent with EPA guidance.
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\26\ 83 FR 27944, June 15, 2018.
\27\ 2014 SO2 Guidance, 24.
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Comment: The NGOs argued that there should be a clear indication of
whether or not there were hours of non-operation (i.e., zero emissions)
for each of the emission units factored into the adjustment factor
calculation and whether non-operation will be counted towards
compliance. They noted that the 2014 SO2 Guidance calls for
the
[[Page 8818]]
calculations to be made only during hours of operation and asserted
that it was not clear how the State determined the 0.37 adjustment
factor and how compliance will be ensured with respect to non-
operation.
Response: We agree with the commenter that it should be clear how
hours of non-operation were accounted for in developing the adjustment
factor and how they will be used in determining compliance. Regarding
the development of the adjustment factor, we have included information
in the docket that displays the facility emission data used by the
State in determining the 0.37 adjustment factor.\28\ This adjustment
factor represents a ratio of the 99th percentile of 30-day average
emissions relative to the 99th percentile of 1-hour average emissions.
To determine the 99th percentile of the 1-hour average emissions, the
State only considered hours corresponding to periods of operation. To
determine the 99th percentile of the 30-day average emission values the
State used a running hourly mean of the most recent 720 hours that
corresponded to periods of operation. As seen in this spreadsheet,
periods of zero emissions that correspond to nonoperation were removed
from consideration in developing the adjustment factor.
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\28\ Spreadsheet ``FMMI_EMISSION_LIMIT_TSD_20151223.xls'' and
Memorandum dated February 6, 2019, from Rynda Kay, EPA Region IX,
Air Quality Analysis Office, to Rulemaking Docket EPA-R09-OAR-2017-
0621.
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We note that there was a period during June 16-17, 2015, in which
39 hours of zero emissions were included in the set of emission data
used in developing the adjustment factor. Additional correspondence
between the EPA, ADEQ and FMMI provided further details indicating that
while no emissions occurred, this period of time corresponds to a
period of operation as defined in Rule C1302 subsection (B)(6).\29\
Specifically, FMMI indicated the electric furnace was receiving power
during this period, and that electric furnace temperature was steadily
increasing. In addition, the vent fume stack fan was also operating and
ventilating during this period. FMMI asserts that during this 39-hour
period, the electric furnace was operating and smelting, but that crust
formation prevented SO2 emissions from the electric furnace
until temperature was sufficient to melt the crust. Operating records
provided by FMMI support these details and indicate that this 39-hour
period represents initial startup after a period of nonoperation.\30\
Based on this information, we consider the inclusion of this 39-hour
period appropriate because conditions at the facility were consistent
with periods of operation that generated no emissions.
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\29\ Email dated September 19, 2018, from Farah Mohammadesmaeili
(ADEQ) to Rynda Kay (EPA), Subject: ``FW: SO2 SIP Data
Inquiry.''
\30\ Spreadsheet ``2013 shutdown data 20181017.xlsx.''
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With respect to the compliance determination, we note that Rule
C1302 subsection (F)(1) requires a compliance demonstration for each
``operating day.'' Subsection (B)(6) of Rule C1302 defines ``operating
day'' as any calendar day in which any of the following occurs:
a. Concentrate is smelted in the Electric furnace or IsaSmelt
furnace;
b. Copper or sulfur bearing materials are processed in the
converters;
c. Blister or scrap copper is processed in the anode furnaces or
mold vessel;
d. Molten metal, including slag, matte or blister copper, is
transferred between vessels;
e. Molten metal is cast into molds, anodes, or other intermediate
or final products;
f. Power is provided to the electric furnace to make or maintain a
molten bath; or
g. The anode furnace is heated to make or maintain a molten bath.
In this rule, compliance with the rolling 30-day emission limit is
calculated by identifying the days during which one or more of the
relevant units was actually operating, and at the end of each operating
day computing average emissions over the most recent 30 operating days.
The emissions from those 30 days are totaled and then divided by 720
(30 days x 24 hours). The approach of determining compliance on the
basis of emissions only during operating days and defining ``operating
day'' as a day with any operation is consistent with the recommendation
in the 2014 SO2 Guidance.\31\ On the other hand, the
determination of compliance on a 720-hour basis, inherently averaging
in the zero emission values of non-operating hours during an operating
day, is not consistent with the recommendation in the 2014
SO2 Guidance that hours without operation be excluded from
the compliance determination.\32\
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\31\ 2014 SO2 Guidance, 32.
\32\ Id. (``The MATS procedure also effectively provides that
hours with no operation have no effect on the calculated average
emission rate, which is a desirable feature in order to focus on how
well controls are operating during operating hours.'')
---------------------------------------------------------------------------
The EPA has evaluated the significance of using this compliance
determination approach for this facility as compared to a method that
excludes all non-operating hours.\33\ In the case of the Miami Smelter,
the use of data only from operating days, as opposed to using data from
all calendar days, substantially limits the inclusion of non-operating
hours. The nature of the process at the Miami Smelter involves
relatively continuous operation, so that the number of non-operating
hours within operating days is minimal. For example, the emission data
used to derive the adjustment factor, representing 12,264 hours,
include only 224 non-operating hours, less than 2 percent of the hours.
The inclusion of these non-operating hours has a negligible impact on
the rolling average, especially at peak values for this facility. For
example, the highest 30-operating day average calculated from the
dataset is 105.9 lb/hr when non-operating hours are excluded compared
to 105.2 lb/hr when non-operating hours are included. Both are well
below the facility-wide 30-day emission limit of 142.45 lb/hr. Also,
among the days represented in the top 10 percent of 30-day averages,
only 0.5 percent of the hours are non-operating hours. As the
compliance methodology for the Miami Smelter is based on an operating
day, consistent with the 2014 SO2 Guidance, and the smelter
operates continuously year-round, these non-operating hours remain
inconsequential in determining compliance with the 30-day limit.
Therefore, we conclude that this deviation from guidance will have
minimal impact and does not prevent this Miami SO2 Plan from
providing for attainment.
---------------------------------------------------------------------------
\33\ See ``Evaluation-FMMIComplianceMethodology.xls'' for the
EPA's evaluation of the Miami Smelter's compliance methodology.
---------------------------------------------------------------------------
The 2014 SO2 Guidance also recommends that the approach
used to calculate the adjustment factor should be consistent with the
approach used to determine compliance with the longer-term limit.\34\
As described above, ADEQ computed the 99th percentile of the 30-day
average emission values used in the development of the longer-term
limit as a 720-rolling hourly average, whereas compliance is determined
using a 30-operating day average. We recalculated the adjustment factor
and resulting emission limit using the compliance methodology outlined
in Rule C1302 and found the difference was small: The adjustment factor
and 30-day limit are 0.368 and 141.80 lb/hr when calculated using a 30-
operating day average compared to 0.370 and 142.45 lb/hr when
calculated as a 720-hour running mean, a 0.4 percent difference. We
[[Page 8819]]
believe this difference is negligible and the conservatism built into
the State's modeling adequately demonstrates that the longer-term
emission limit in Rule C1302 provides for attainment. The State's
modeling predicts a design value of 194.1 micrograms per cubic meter
([mu]g/m\3\), whereas the standard is 196.4 [mu]g/m\3\ (75 ppb),
providing room for this slightly higher limit in Rule C1302.
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\34\ 2014 SO2 Guidance, Appendix C, C-3.
---------------------------------------------------------------------------
Comment: The NGOs requested that the EPA take a fresh look at this
rulemaking and issue a revised proposal for public notice and comment.
Response: We have reexamined our proposed rulemaking and have
concluded that no revised notice of proposed rulemaking is warranted.
For the reasons described in our proposal and in the preceding
responses to comments, we find that the Miami SO2 Plan meets
all applicable requirements under the CAA and the EPA's implementing
regulations. Accordingly, we are finalizing our approval of the Miami
SO2 Plan.
III. The EPA's Final Action
The EPA is approving the Miami SO2 Plan, which includes
Arizona's attainment demonstration for the Miami SO2 NAA and
addresses requirements for RFP, RACT/RACM, base-year and projected
emission inventories, new source review, enforceable emissions limits
and control measures, and contingency measures. For the reasons
described in our proposal and the related concurrence documents,\35\
the EPA is also approving the BLP/AERMOD Hybrid Approach as an
alternative model to represent emissions from Miami Smelter roofline in
the Miami SO2 Plan under 40 CFR 51.112(a)(2). The EPA
determines that the Miami SO2 Plan meets applicable
requirements of sections 110, 172, 191 and 192 of the CAA for the 2010
SO2 NAAQS.
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\35\ ``Concurrence Request for Approval of Alternative Model:
BLP/AERMOD Hybrid Approach for Modeling Buoyant Roofline Sources at
the FMMI Copper Smelter in Miami, AZ'' (March 12, 2018) and ``Model
Clearinghouse Review of a BLP/AERMOD Hybrid Alternative Model
Approach for Modeling Buoyant Roofline Sources at the FMMI Copper
Smelter in Miami, AZ'' (March 26, 2018).
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IV. Statutory and Executive Order Reviews
Under the CAA, the Administrator is required to approve a SIP
submission that complies with the provisions of the Act and applicable
Federal regulations. 42 U.S.C. 7410(k); 40 CFR 52.02(a). Thus, in
reviewing SIP submissions, the EPA's role is to approve state choices,
provided that they meet the criteria of the CAA. Accordingly, this
action merely approves state law as meeting Federal requirements and
does not impose additional requirements beyond those imposed by state
law. For that reason, this proposed action:
Is not a ``significant regulatory action'' subject to
review by the Office of Management and Budget under Executive Order
12866 58 FR 51735, October 4, 1993) and 13563 (76 FR 3821, January 21,
2011);
Is not an Executive Order 13771 (82 FR 9339, February 2,
2017) regulatory action because SIP approvals are exempted under
Executive Order 12866;
Does not impose an information collection burden under the
provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
Is certified as not having a significant economic impact
on a substantial number of small entities under the Regulatory
Flexibility Act (5 U.S.C. 601 et seq.);
Does not contain any unfunded mandate or significantly or
uniquely affect small governments, as described in the Unfunded
Mandates Reform Act of 1995 (Pub. L. 104-4);
Does not have Federalism implications as specified in
Executive Order 13132 (64 FR 43255, August 10, 1999);
Is not an economically significant regulatory action based
on health or safety risks subject to Executive Order 13045 (62 FR
19885, April 23, 1997);
Is not a significant regulatory action subject to
Executive Order 13211 (66 FR 28355, May 22, 2001);
Is not subject to requirements of section 12(d) of the
National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272
note) because application of those requirements would be inconsistent
with the CAA; and
Does not provide the EPA with the discretionary authority
to address, as appropriate, disproportionate human health or
environmental effects, using practicable and legally permissible
methods, under Executive Order 12898 (59 FR 7629, February 16, 1994).
In addition, the SIP is not approved to apply on any Indian
reservation land or in any other area where the EPA or an Indian tribe
has demonstrated that a tribe has jurisdiction. In those areas of
Indian country, the rule does not have tribal implications and will not
impose substantial direct costs on tribal governments or preempt tribal
law as specified by Executive Order 13175 (65 FR 67249, November 9,
2000).
The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the
Small Business Regulatory Enforcement Fairness Act of 1996, generally
provides that before a rule may take effect, the agency promulgating
the rule must submit a rule report, which includes a copy of the rule,
to each House of the Congress and to the Comptroller General of the
United States. The EPA will submit a report containing this action and
other required information to the U.S. Senate, the U.S. House of
Representatives, and the Comptroller General of the United States prior
to publication of the rule in the Federal Register. A major rule cannot
take effect until 60 days after it is published in the Federal
Register. This action is not a ``major rule'' as defined by 5 U.S.C.
804(2).
Under section 307(b)(1) of the Clean Air Act, petitions for
judicial review of this action must be filed in the United States Court
of Appeals for the appropriate circuit by May 13, 2019. Filing a
petition for reconsideration by the Administrator of this final rule
does not affect the finality of this action for the purposes of
judicial review nor does it extend the time within which a petition for
judicial review may be filed and shall not postpone the effectiveness
of such rule or action. This action may not be challenged later in
proceedings to enforce its requirements. (See section 307(b)(2)).
List of Subjects in 40 CFR Part 52
Environmental protection, Air pollution control, Incorporation by
Reference, Intergovernmental relations, Reporting and recordkeeping
requirements, Sulfur oxides.
Authority: 42 U.S.C. 7401 et seq.
Dated: February 21, 2019.
Deborah Jordan,
Acting Regional Administrator, EPA Region IX.
40 CFR part 52 is amended as follows:
PART 52--APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS
0
1. The authority citation for part 52 continues to read as follows:
Authority: 42.U.S.C. 7401 et seq.
Subpart D--Arizona
0
2. In Sec. 52.120, table 1 in paragraph (e) is amended by adding the
entry ``Arizona State Implementation Plan Revision: Miami Sulfur
Dioxide Nonattainment Area for the 2010 SO2 NAAQS, excluding
Appendix D'' after the entry ``SIP Revision: Hayden Lead Nonattainment
Area, excluding Appendix C'' to read as follows:
Sec. 52.120 Identification of plan.
* * * * *
(e) * * *
[[Page 8820]]
Table 1--EPA-Approved Non-Regulatory and Quasi-Regulatory Measures
[Excluding certain resolutions and statutes, which are listed in tables 2 and 3, respectively] \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Applicable
geographic or
Name of SIP provision nonattainment area State submittal date EPA approval date Explanation
or title/subject
--------------------------------------------------------------------------------------------------------------------------------------------------------
* * * * * * *
--------------------------------------------------------------------------------------------------------------------------------------------------------
Part D Elements and Plans (Other Than for the Metropolitan Phoenix or Tucson Areas)
--------------------------------------------------------------------------------------------------------------------------------------------------------
* * * * * * *
Arizona State Implementation Miami, AZ Sulfur March 9, 2017.............. [insert Federal Register Adopted by the Arizona Department
Plan Revision: Miami Sulfur Dioxide citation], March 12, 2019. of Environmental Quality on
Dioxide Nonattainment Area for Nonattainment Area. March 8, 2017.
the 2010 SO2 NAAQS, excluding
Appendix D.
* * * * * * *
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Table 1 is divided into three parts: Clean Air Act Section 110(a)(2) State Implementation Plan Elements (excluding Part D Elements and Plans), Part
D Elements and Plans (other than for the Metropolitan Phoenix or Tucson Areas), and Part D Elements and Plans for the Metropolitan Phoenix and Tucson
Areas.
* * * * *
[FR Doc. 2019-04389 Filed 3-11-19; 8:45 am]
BILLING CODE 6560-50-P