[Federal Register Volume 84, Number 174 (Monday, September 9, 2019)]
[Proposed Rules]
[Pages 47216-47231]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-19413]


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

ENVIRONMENTAL PROTECTION AGENCY

40 CFR Parts 52 and 81

[EPA-R04-OAR-2018-0510; FRL-9999-43-Region 4]


Air Plan Approval and Designation of Areas; FL; Source-Specific 
SO2 Permit Limits & Redesignation of Hillsborough-Polk 2010 1-Hr SO2 
Nonattainment Area to Attainment & Mulberry Unclassifiable Area to 
Attainment/Unclassifiable

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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

SUMMARY: The Environmental Protection Agency (EPA) is proposing to 
approve state implementation plan (SIP) revisions and two redesignation 
requests provided by the State of Florida, through the Florida 
Department of Environmental Protection (FDEP), related to the 2010 1-
hour sulfur dioxide (SO2) national ambient air quality 
standard (NAAQS or standard). Specifically, EPA is proposing to approve 
a December 1, 2017, SIP revision (as supplemented through a February 
15, 2019 draft SIP revision discussed below) that includes 
SO2 multi-unit permit limits and associated compliance and 
monitoring parameters for Mosaic Fertilizer LLC's New Wales facility 
(Mosaic New Wales) and Bartow facility (Mosaic Bartow), both located in 
Polk County, Florida. The December 1, 2017, SIP revision also includes 
a modeling analysis to demonstrate that the Hillsborough-Polk 
SO2 nonattainment area (hereinafter referred to as the 
``Hillsborough-Polk Area'') attains the SO2 NAAQS with these 
permit limits. EPA is also proposing to approve, through parallel 
processing, a draft February 15, 2019, request to redesignate the 
Hillsborough-Polk Area to attainment for the 1-hour SO2 
NAAQS and associated SIP revision containing the State's plan for 
maintaining attainment of the standard in the Area. As mentioned above, 
a draft February 15, 2019, SIP revision also revises the modeling 
analysis in the 2017 SIP revision. Additionally, the draft February 15, 
2019, SIP revisions contain a base-year emissions inventory for the 
Area and certify that the Area meets nonattainment new source review 
(NNSR) requirements. EPA is proposing to approve the draft February 15, 
2019, SIP revisions through parallel processing. In addition, EPA is 
proposing to approve, through parallel processing, a draft February 15, 
2019, request to redesignate the Mulberry Unclassifiable Area 
(hereinafter referred to as the ``Mulberry Area'') to attainment/
unclassifiable for the 2010 1-hour SO2 NAAQS.

DATES: Comments must be received on or before October 9, 2019.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R04-
OAR-2018-0510 at http://www.regulations.gov. Follow the online 
instructions for submitting comments. Once submitted, comments cannot 
be edited or removed from Regulations.gov. EPA may publish any comment 
received to its public docket. Do not submit electronically any 
information you consider to be Confidential Business Information (CBI) 
or other information whose disclosure is restricted by statute. 
Multimedia submissions (audio, video, etc.) must be accompanied by a 
written comment. The written comment is considered the official comment 
and should include discussion of all points you wish to make. EPA will 
generally not consider comments or comment contents located outside of 
the primary submission (i.e., on the web, cloud, or other file sharing 
system). For additional submission methods, the full EPA public comment 
policy, information about CBI or multimedia submissions, and general 
guidance on making effective comments, please visit http://www2.epa.gov/dockets/commenting-epa-dockets.

FOR FURTHER INFORMATION CONTACT: Madolyn Sanchez, Air Regulatory 
Management Section, Air Planning and Implementation Branch, Air and 
Radiation Division, U.S. Environmental Protection Agency, Region 4, 61 
Forsyth Street SW, Atlanta, Georgia 30303-8960. Ms. Sanchez may be 
reached by phone at (404) 562-9644 or via electronic mail at 
[email protected].

SUPPLEMENTARY INFORMATION:

Table of Contents

I. What is parallel processing?
II. What are the actions EPA is proposing to take?
III. Background

[[Page 47217]]

IV. What are the criteria for redesignation?
V. Why is EPA proposing these actions?
VI. What is EPA's analysis of Florida's source-specific 
SO2 permit limits?
VII. What actions are being proposed for the Hillsborough-Polk Area?
VIII. What is EPA's analysis of the redesignation request for the 
Mulberry Area?
IX. What is the effect of EPA's proposed actions?
X. Incorporation by Reference
XI. Proposed Actions
XII. Statutory and Executive Order Reviews

I. What is parallel processing?

    Parallel processing refers to a process that utilizes concurrent 
state and Federal proposed rulemaking actions. Generally, the state 
submits a copy of the proposed regulation or other revisions to EPA 
before conducting its public hearing and completing its public comment 
process under state law. EPA reviews this proposed state action and 
prepares a notice of proposed rulemaking under Federal law. In some 
cases, EPA's notice of proposed rulemaking is published in the Federal 
Register during the same time frame that the state is holding its 
public hearing and conducting its public comment process. The state and 
EPA then provide for concurrent public comment periods on both the 
state action and Federal action. If, after completing its public 
comment process and after EPA's public comment process has run, the 
state changes its final submittal from the proposed submittal, EPA 
evaluates those changes and decides whether to publish another notice 
of proposed rulemaking in light of those changes or to proceed to 
taking final action on its proposed action and describe the state's 
changes in its final rulemaking action. Any final rulemaking action by 
EPA will occur only after the final submittal has been adopted by the 
state and formally provided to EPA.
    In the instant case, however, EPA's and Florida's processes have 
not been perfectly concurrent. The State submitted its first SIP 
revision for the Area to EPA in December 2017. Then, on February 15, 
2019, Florida submitted proposed SIP revisions related to the 2010 1-
hour SO2 standard for the Hillsborough-Polk Area, including 
an amendment to the December 2017, SIP revision, along with proposed 
requests to redesignate the Hillsborough-Polk and Mulberry Areas. These 
submittals were noticed for public comment by the State on February 15, 
2019, and have not yet been submitted in final form. The State's public 
comment period closed on March 18, 2019. The State only received 
comments from EPA which are provided in the docket for this proposed 
rulemaking. Florida requested that EPA parallel process these proposed 
submittals while the State waits for the multi-unit permit limits to 
become state-enforceable on August 31, 2019. The State's intention is 
to submit its final SIP revisions and redesignation requests in early 
September 2019. After Florida submits these formal SIP revisions and 
requests (including responses to EPA's comments), EPA will evaluate the 
submittals. If the State changes the formal submittals from the 
proposed submittals, EPA will evaluate those changes for significance. 
If EPA finds any such changes to be significant, then the Agency 
intends to determine whether to re-propose the actions based upon the 
revised submissions or to proceed to take final action on the 
submittals as changed by the State. Although EPA was unable to have a 
concurrent public comment process with the State, Florida's request for 
parallel processing allows EPA to begin to take action on the State's 
proposed submittals in advance of formal, final submissions.

II. What are the actions EPA is proposing to take?

    EPA is proposing to take the following seven separate but related 
actions: (1) Approve and incorporate the SO2 permit limits 
and associated compliance and monitoring parameters for Mosaic New 
Wales and Mosaic Bartow into the SIP; (2) approve the base-year 
emissions inventory pursuant to Clean Air Act (CAA or Act) section 
172(c)(3) for the Hillsborough-Polk Area and incorporate it into the 
SIP; (3) concur with Florida's certification pursuant to CAA section 
172(c)(5) that its existing NNSR requirements apply to the 
Hillsborough-Polk Area; (4) determine that the air quality modeling 
submitted by the State demonstrates that the Hillsborough-Polk Area 
will have attained the 2010 SO2 NAAQS as a result of 
compliance with the multi-unit permit limits at Mosaic New Wales and 
Mosaic Bartow; (5) approve Florida's plan for maintaining the 2010 1-
hour SO2 NAAQS in the Hillsborough-Polk Area through 2032 
and incorporate it into the SIP pursuant to section 175A of the CAA; 
(6) redesignate the Hillsborough-Polk Area to attainment for the 2010 
1-hour SO2 NAAQS; and (7) redesignate the Mulberry Area to 
attainment/unclassifiable for the 2010 1-hour SO2 NAAQS 
based on air quality modeling. Because attainment of the SO2 
NAAQS is dependent on making the multi-unit permit limits and 
associated compliance and monitoring parameters for Mosaic New Wales 
and Mosaic Bartow permanent and enforceable measures, EPA cannot take 
final action on items 4-7, above, unless it finalizes its proposal to 
approve and incorporate these limits and parameters into the SIP.\1\
---------------------------------------------------------------------------

    \1\ FDEP has committed to submit the redesignation requests and 
SIP revisions soon after the SO2 permit limits become 
state-enforceable on August 31, 2019. As described above, EPA will 
not take final action on its proposals associated with the February 
15, 2019, drafts until after these redesignation requests and SIP 
revisions are formally submitted to EPA in early September 2019. As 
a part of the final SIP submittals, Florida will provide emissions 
data to show compliance with the SO2 permit limits that 
are the subject of this proposed rulemaking.
---------------------------------------------------------------------------

    The Hillsborough-Polk Area is comprised of the portion of 
Hillsborough and Polk Counties encompassed by the polygon with the 
vertices using Universal Transverse Mercator (UTM) coordinates in UTM 
zone 17 with datum North American Datum 83 (NAD83) as follows: 390,500 
E, 3,073,500 N; 390,500 E, 3,083,500 N; 400,500 E, 3,083,500 N; 400,500 
E, 3,073,500 N. The Hillsborough-Polk Area contains one major point 
source for SO2 emissions--Mosaic New Wales.
    The Mulberry Area is that portion of Hillsborough and Polk Counties 
encompassed by the polygon with the vertices using UTM coordinates in 
UTM zone 17 with datum NAD83 starting with the Northwest Corner and 
proceeding to the Northeast as follows: 390,500 E, 3,083,500 N; 410,700 
E, 3,091,600 N; 412,900 E, 3,089,800 N; 412,900 E, 3,084,600 N; 400,500 
E, 3,073,50 N; 400,500 E, 3,083,500 N. The Mulberry Area is directly 
adjacent to the Hillsborough-Polk Area and contains one major point 
source for SO2 emissions--Mosaic Bartow. In addition, there 
are two major SO2 point sources located within 10 kilometers 
(km) of the Hillsborough-Polk Area and the Mulberry Area--Mosaic's 
South Pierce facility and Tampa Electric Company's (TECO's) Polk Power 
Station.

III. Background

    On June 2, 2010, EPA revised the primary SO2 NAAQS, 
establishing a new 1-hour SO2 standard of 75 parts per 
billion (ppb). See 75 FR 35520 (June 22, 2010). Under EPA's regulations 
at 40 CFR part 50, the 2010 1-hour SO2 NAAQS is met at a 
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 (based on the rounding convention in 40 CFR part 50, appendix 
T). See 40 CFR 50.17. Ambient air quality monitoring data for the 3-
year period must meet a data completeness requirement. A year meets

[[Page 47218]]

data completeness requirements when all four quarters are complete, and 
a quarter is complete when at least 75 percent of the sampling days for 
each quarter have complete data. A sampling day has complete data if 75 
percent of the hourly concentration values, including state-flagged 
data affected by exceptional events which have been approved for 
exclusion by the Administrator, are reported.\2\ The 2010 1-hour 
SO2 standard is violated at an ambient air quality 
monitoring site (or in the case of dispersion modeling, at an ambient 
air quality receptor location) when the 3-year average of the annual 
99th percentile of the daily maximum 1-hour average concentrations 
exceeds 75 ppb, as determined in accordance with Appendix T of 40 CFR 
part 50.
---------------------------------------------------------------------------

    \2\ See 40 CFR part 50, appendix T, section 3(b).
---------------------------------------------------------------------------

    Upon promulgation of a new or revised NAAQS, the CAA requires EPA 
to designate as nonattainment any area that does not meet (or that 
contributes to ambient air quality in a nearby area that does not meet) 
the NAAQS. Effective on April 9, 2018, EPA designated the Hillsborough-
Polk Area as nonattainment based on air dispersion modeling and 
designated the Mulberry Area as unclassifiable for the 2010 1-hour 
SO2 NAAQS.\3\ See 83 FR 1098 (January 9, 2018). Under the 
CAA, SO2 nonattainment areas must attain the NAAQS as 
expeditiously as practicable but not later than five years after the 
April 9, 2018, effective date of the designation. See CAA section 
192(a). Therefore, the Hillsborough-Polk Area's applicable attainment 
date is no later than April 9, 2023.
---------------------------------------------------------------------------

    \3\ EPA designated the Mulberry Area as unclassifiable due to 
the uncertainty regarding possible contribution from Mosaic Bartow 
to the modeled violations in the Hillsborough-Polk Area. See Chapter 
9 of the Technical Support Document for the Round 3 Designations for 
the 2010 1-Hour SO2 NAAQS located in the docket for the 
designation at Docket ID No. EPA-HQ-OAR-2017-0003-0635.
---------------------------------------------------------------------------

    EPA's nonattainment designation for the Hillsborough-Polk Area 
triggered an obligation for Florida to develop a nonattainment area SIP 
revision addressing certain requirements under CAA title I, part D, 
subpart 1 (hereinafter ``Subpart 1''), and to submit that SIP revision 
to EPA in accordance with the deadlines in title I, part D, subpart 5 
(hereinafter ``Subpart 5'').\4\ Subpart 1 contains the general 
requirements for nonattainment areas for criteria pollutants, including 
requirements to develop a SIP that provides for the implementation of 
reasonably available control measures (RACM), requires reasonable 
further progress (RFP), includes base-year and attainment-year 
emissions inventories, a SIP-approved NNSR permitting program that 
accounts for growth in the area, enforceable emission limitations and 
other such control measures, and provides for the implementation of 
contingency measures. This SIP revision is due within 18 months 
following the April 9, 2018, effective date of designation (i.e., 
October 9, 2019).\5\ See CAA section 191(a).
---------------------------------------------------------------------------

    \4\ No requirements were triggered as a result of the 
unclassifiable designation for the Mulberry Area.
    \5\ If EPA redesignates the Hillsborough-Polk Area to 
attainment, a nonattainment SIP revision will not be required.
---------------------------------------------------------------------------

IV. What are the criteria for redesignation?

    The CAA provides the requirements for redesignating a nonattainment 
area to attainment. Specifically, section 107(d)(3)(E) of the CAA 
allows for redesignation provided that the following criteria are met: 
(1) The Administrator determines that the area has attained the 
applicable NAAQS; (2) the Administrator has fully approved the 
applicable implementation plan for the area under section 110(k); (3) 
the Administrator determines that the improvement in air quality is due 
to permanent and enforceable reductions in emissions resulting from 
implementation of the applicable SIP and applicable federal air 
pollutant control regulations, and other permanent and enforceable 
reductions; (4) the Administrator has fully approved a maintenance plan 
for the area as meeting the requirements of section 175A; and (5) the 
state containing such area has met all requirements applicable to the 
area for purposes of redesignation under section 110 and part D of the 
CAA.
    On April 16, 1992 (57 FR 13498), EPA provided guidance on 
redesignations in the General Preamble for the Implementation of title 
I of the CAA Amendments of 1990 and supplemented this guidance on April 
28, 1992 (57 FR 18070). EPA has provided further guidance on processing 
redesignation requests in the following documents:

    1. ``Procedures for Processing Requests to Redesignate Areas to 
Attainment,'' Memorandum from John Calcagni, Director, Air Quality 
Management Division, September 4, 1992 (hereinafter referred to as 
the ``Calcagni Memorandum'');
    2. ``State Implementation Plan (SIP) Actions Submitted in 
Response to Clean Air Act (CAA) Deadlines,'' Memorandum from John 
Calcagni, Director, Air Quality Management Division, October 28, 
1992 (hereinafter referred to as the ``1992 Calcagni Memorandum'');
    3. ``Part D New Source Review (Part D NSR) Requirements for 
Areas Requesting Redesignation to Attainment,'' Memorandum from Mary 
D. Nichols, Assistant Administrator for Air and Radiation, October 
14, 1994 (hereinafter referred to as the ``Nichols Memorandum''); 
and
    4. ``Guidance for 1-Hour SO2 Nonattainment Area SIP 
Submissions,'' Memorandum from Stephen D. Page, April 23, 2014 
(hereinafter referred to as the ``SO2 Nonattainment Area 
Guidance'').

    EPA's SO2 Nonattainment Area Guidance discusses the CAA 
requirements that air agencies need to address when implementing the 
2010 SO2 NAAQS in areas designated as nonattainment for the 
standard. The guidance includes recommendations for air agencies to 
consider as they develop SIPs to satisfy the requirements of sections 
110, 172, 175A, 191, and 192 of the CAA to show future attainment and 
maintenance of the 2010 SO2 NAAQS. Additionally, the 
SO2 Nonattainment Area Guidance provides recommendations for 
air agencies to consider as they develop redesignation requests and 
maintenance plans to satisfy the requirements of sections 107(d)(3)(E) 
and 175A.

V. Why is EPA proposing these actions?

    EPA has evaluated and is proposing to approve the base-year 
nonattainment emissions inventory and concurs with FDEP's certification 
that its existing SIP-approved NNSR permitting program applies to the 
Hillsborough-Polk Area because they satisfy the requirements of CAA 
sections 172(c)(3) and 172(c)(5), respectively. As discussed in greater 
detail in Section VI of this notice, EPA is also proposing to approve 
and incorporate the SO2 permit limits and associated 
compliance and monitoring parameters for Mosaic New Wales and Mosaic 
Bartow into the SIP. In addition, EPA is proposing to determine that 
the air quality modeling submitted by the State demonstrates that the 
Hillsborough-Polk Area will have attained the 2010 SO2 NAAQS 
as a result of compliance with the permit limits at Mosaic New Wales 
and Mosaic Bartow and that the Area will meet the requirements for 
redesignation as set forth in section 107(d)(3)(E), including the 
maintenance plan requirements under section 175A of the CAA, provided 
that the state submits a final SIP consistent with that outlined above, 
including the permit limits, parameters, and related information, and 
EPA approves the SIP.
    Also, as a result of the compliance with the multi-unit permit 
limits at Mosaic New Wales and Mosaic Bartow, EPA proposes to determine 
that the Mulberry Area will have attained the 1-hour SO2 
NAAQS and thus will meet

[[Page 47219]]

the requirements for redesignation from unclassifiable to attainment/
unclassifiable.

VI. What is EPA's analysis of Florida's source-specific SO[bdi2] permit 
limits?

    Florida's December 1, 2017, source-specific SIP revision includes 
SO2 multi-unit permit limits and associated compliance and 
monitoring provisions from air construction permits for Mosaic New 
Wales (Permit No. 1050059-106-AC) and Mosaic Bartow (Permit No. 
1050046-050-AC). The SIP revision also includes modeling to demonstrate 
that the Hillsborough-Polk Area will attain the SO2 NAAQS as 
a result of compliance with these multi-unit permit limits. Florida's 
February 15, 2019, draft SIP submittal contains changes to this 
modeling and administrative corrections to the aforementioned permits.
    Mosaic New Wales and Mosaic Bartow are phosphate fertilizer 
manufacturing plants that employ a process of reacting phosphate rock 
with sulfuric acid to produce phosphoric acid, which is then converted 
into several different fertilizer products and animal feed ingredients. 
The sulfuric acid needed for the process is produced by sulfuric acid 
plants (SAPs), which are the largest SO2 emitting units at 
these sites. Both facilities are sulfur burning, double conversion, and 
double absorption plants of Leonard-Monsanto design.\6\ The SAPs burn 
sulfur with dried atmospheric oxygen to produce SO2, which 
is catalytically oxidized to sulfur trioxide (SO3), which is 
then absorbed in sulfuric acid.
---------------------------------------------------------------------------

    \6\ A double conversion, double absorption plant efficiently 
converts SO2 to SO3, then SO3 
reacts in a mixture of water and sulfuric acid 
(H2SO4) to produce more 
H2SO4. In a double absorption system, the 
conversion efficiency from SO2 to SO3 is at 
least 99.7 percent.
---------------------------------------------------------------------------

    To reduce SO2 emissions from the SAPs, Mosaic has 
replaced the vanadium catalysts with more efficient catalysts to enable 
Mosaic New Wales and Mosaic Bartow to meet the new SO2 
permit limits. Mosaic Bartow and Mosaic New Wales began installation of 
the catalyst replacements in 2016 and 2017, respectively, and completed 
installation in April 2019.\7\ The new catalysts allow for more 
SO2 to be captured for process purposes rather than being 
emitted into the atmosphere.
---------------------------------------------------------------------------

    \7\ See the May 23, 2019, email from Mosaic Fertilizer, LLC to 
EPA Region 4 Air Planning Implementation Branch, Air Regulatory 
Management Section and Florida Department of Environmental 
Protection, Division of Air Resource Management located in the 
docket for this proposed rulemaking. FDEP required Mosaic to install 
these catalysts through Permit No. 1050059-101-AC (Mosaic New Wales) 
and No. 1050046-050-AC (Mosaic Bartow).
---------------------------------------------------------------------------

    On October 30, 2017, FDEP issued Permit No. 1050059-106-AC for 
Mosaic New Wales requiring compliance with a SO2 multi-unit 
permit limit of 1,090 pounds per hour (lb/hr) across all five SAPs 
(Nos. 1 through 5) based on a 24-hour block average and with associated 
specific compliance and monitoring provisions. On July 3, 2017, FDEP 
issued Permit No. 1050046-050-AC for Mosaic Bartow requiring compliance 
with an SO2 multi-unit permit limits of 1,100 lb/hr across 
all three SAPs (No. 4, No. 6 and No. 5) based on a 24-hour block 
average and with associated compliance and monitoring provisions. 
Mosaic is required to comply with these permit conditions no later than 
August 31, 2019.\8\ The construction permits impose the new limits for 
scenarios where any number of units are operating at each respective 
facility while retaining the current individual unit limits as shown in 
Tables 1 and 2.
---------------------------------------------------------------------------

    \8\ FDEP incorporated these permit limits into Title V Permit 
No. 1050059-107-AV (Mosaic New Wales) and No. 1050046-053-AV (Mosaic 
Bartow).

              Table 1--Mosaic New Wales SO2 Source Changes
------------------------------------------------------------------------
                                         SO2 permit limits (lb/hr)
                                 ---------------------------------------
             Source                Individual (not
                                      changing)          New 5-unit *
------------------------------------------------------------------------
SAP1............................                496  Combined emissions
                                                      cannot exceed
                                                      1,090.
SAP2............................                496
SAP3............................                496
SAP4............................              483.3
SAP5............................              483.3
------------------------------------------------------------------------
* SO2 permit limit is a 24-hour block average.


                Table 2--Mosaic Bartow SO2 Source Changes
------------------------------------------------------------------------
                                         SO2 permit limits (lb/hr)
                                 ---------------------------------------
             Source                Individual (not
                                      changing)          New 3-unit *
------------------------------------------------------------------------
SAP4............................              433.3  Combined emissions
                                                      cannot exceed
                                                      1,100.
SAP5............................              433.3
SAP6............................              433.3
------------------------------------------------------------------------
* SO2 permit limit is a 24-hour block average.

    The potential to emit for SAPs 1-5 at Mosaic New Wales and SAPs 4-6 
at Mosaic Bartow was previously 10,750 tons per year (tpy) and 5,694 
tpy, respectively. With the new multi-unit permit limits implemented at 
Mosaic New Wales and Mosaic Bartow, FDEP expects the potential to emit 
to be 4,774 tpy and 4,818 tpy, respectively. This is approximately a 
42-percent drop in total allowable emissions for both facilities, 
combined. At maximum production, with all SAPs in operation, overall 
SO2 emissions are expected to be reduced by approximately 
5,930 tpy at Mosaic New Wales and 876 tpy at Mosaic Bartow. FDEP 
projects that actual SO2 emissions will decrease by 36 
percent from 2016 to 2020.
    On January 11, 2019, FDEP issued Administrative Permit Corrections 
to

[[Page 47220]]

the air construction permits identified above. These corrections are 
contained in Permit No. 1050059-114-AC for Mosaic New Wales and Permit 
No. 1050046-063-AC for Mosaic Bartow and do not modify the multi-unit 
permit limits or the associated compliance and monitoring provisions. 
The notices associated with these permits state that the corrections 
merely remove unnecessary and confusing language from the permit 
provisions that contain the emissions caps.\9\ Florida's February 15, 
2019, draft SIP revisions ask EPA to incorporate the corrections from 
Permit Nos. 1050059-114-AC and 050046-063-AC into the SIP.
---------------------------------------------------------------------------

    \9\ The Administrative Permit Corrections and associated notices 
are included in Appendix C and Appendix H of Florida's February 15, 
2019 draft SIP revisions contained in the docket for this proposed 
rulemaking. The corrections remove the phrase ``Any requested 
revisions to this emissions limit requires air dispersion modeling 
review and written approval from the Department's Meteorology and 
Air Modeling Section in the Office of Business Planning to confirm 
SO2 NAAQS compliance'' from the provisions establishing 
the multi-unit permit limits.
---------------------------------------------------------------------------

    On March 22, 2019, Florida submitted a letter to EPA explaining the 
administrative corrections and clarifying which permit conditions that 
it would like EPA to incorporate into the SIP.\10\ FDEP is requesting 
that EPA incorporate the following conditions from Permit Nos. 
10500046-106-AC and 1050046-050-AC: \11\ (1) Section III, Subsection A, 
Specific Condition 3 (as corrected by Permit Nos. 1050059-114-AC and 
Permit No. 1050046-063-AC)--establishing the five-unit permit limit of 
1,090 lb/hr for Mosaic New Wales and the three-unit permit limit of 
1,100 lb/hr for Mosaic Bartow, each based on 24-hour block average, and 
applicable during all periods of operation; \12\ (2) Section III, 
Subsection A Specific Condition 4--requiring the facilities to use 
certified SO2 continuous emissions monitoring system (CEMS) 
data to demonstrate initial compliance with the new SO2 
permit limit; and (3) Section III, Subsection A, Specific Condition 5--
requiring the facilities to keep records of the initial compliance 
demonstration that include the SO2 CEMS data and sulfuric 
acid production rate (in tons per hour) during the demonstration.
---------------------------------------------------------------------------

    \10\ See Florida's March 22, 2019, clarification letter 
contained in the docket for this proposed rulemaking.
    \11\ The permit condition numbers are the same for each permit.
    \12\ Permit condition Section III, Subsection A, Specific 
Condition 3 requires compliance with the emissions caps within the 
same 24-hour block averaging period (6:00 a.m. to 6:00 a.m.) and in 
scenarios when any combination of any number of the SAPs are not in 
operation and when any number of the SAPs are in operation. See 
Appendices B, C, G, and H of Florida's February 19, 2019 draft 
redesignation SIP submission in the docket for this proposed 
rulemaking.
---------------------------------------------------------------------------

    The Mosaic New Wales and Mosaic Bartow air construction permits 
include specific conditions regarding initial compliance with the 
SO2 permit limits using CEMS. Florida's SIP-approved 
regulations for SAPs, at Rule 62-296.402, Florida Administrative Code 
(F.A.C.), require the owner or operator of a SAP to install and operate 
CEMS according to appendix B of 40 CFR part 60, and Chapter 62-297, 
F.A.C., which specifies how stationary sources demonstrate compliance 
with the applicable permit limits.\13\ These applicable requirements 
require compliance with the permit limits on an ongoing basis. For each 
SAP at each source, a CEMS will be used to determine compliance with 
the 24-hour average permit limit for SO2. The CEMS shall be 
calibrated, maintained and operated as specified in 40 CFR 60.84.
---------------------------------------------------------------------------

    \13\ See Florida's March 22, 2019 clarification letter in the 
docket for this proposal action.
---------------------------------------------------------------------------

    The December 1, 2017, SIP revision includes an air dispersion 
modeling analysis to show attainment of the 2010 SO2 NAAQS 
in the Hillsborough-Polk Area. The modeling used 1-hour emission rates 
calculated from final multi-unit permit limits of 1,090 lb/hr and 1,100 
lb/hr for New Wales and Bartow, respectively, using adjustment factors 
derived following the procedures in EPA's SO2 Nonattainment 
Area Guidance. Florida's draft February 15, 2019, SIP revision updated 
this modeling. FDEP's modeling complied with all applicable EPA rules 
and guidance, including Appendix W to 40 CFR part 51: The Guideline on 
Air Quality Models (Appendix W) and the SO2 NAAQS Designations Modeling 
Technical Assistance Document.\14\ For more information on the modeling 
analysis, see section VII.C of this notice and the Air Modeling 
Technical Support Document (TSD).\15\ For details on how Florida 
established the 24-hour multi-unit SO2 permit limits, see 
the longer term averaging (LTA) TSD.\16\ EPA included both TSDs in the 
docket for this proposing rulemaking.
---------------------------------------------------------------------------

    \14\ SO2 National Ambient Air Quality Standards 
Designations Modeling Technical Assistance Document, Office of Air 
Quality Planning and Standards, U.S. Environmental Protection 
Agency, Research Triangle Park, North Carolina 27711, available at: 
https://www.epa.gov/sites/production/files/2016-06/documents/so2modelingtad.pdf.
    \15\ This TSD is entitled ``U.S. Environmental Protection Agency 
Technical Support Document (TSD) for the Air Quality Modeling 
Analysis Supporting the Proposed Redesignations for the 
Hillsborough--Polk and Mulberry, Florida Sulfur Dioxide 
(SO2) Areas.''
    \16\ This TSD is entitled ``U.S. Environmental Protection Agency 
Technical Support Document (TSD) for the Longer Term Average Sulfur 
Dioxide (SO2) Permit Limits for the Mosaic New Wales and 
Bartow Fertilizer Facilities.''
---------------------------------------------------------------------------

    Based on a review of Florida's December 1, 2017, SIP revision, as 
modified through its February 15, 2019, draft SIP revision, EPA 
believes that the 24-hour block average SO2 multi-unit 
permit limits described above provide an appropriate alternative to 
establishing a 1-hour average permit limit for each unit at Mosaic New 
Wales and Mosaic Bartow. The State has used a suitable database and has 
derived adjustment factors that yielded permit limits that have 
comparable stringency to the 1-hour average limits that would otherwise 
have been necessary to provide for attainment. While the 24-hour block 
average allows for occasions in which emissions may be higher than the 
level that would be allowed with the 1-hour limit, the State's caps 
compensate by requiring average emissions to be lower than the level 
that would otherwise have been required by 1-hour average limits. For 
more information on how Florida established the SO2 permit 
limits, please refer to the LTA discussion presented in TSD. For 
reasons discussed in the LTA TSD and explained in more detail in EPA's 
SO2 Nonattainment Area Guidance, EPA believes that 
appropriately set longer term average limits provide a reasonable basis 
by which permit limits may provide for attainment. Based on its review 
of this information as well as the information in the State's 2017 and 
2019 SIP revisions, EPA is proposing to find that the 24-hour average 
limits for Mosaic New Wales and Mosaic Bartow provide for attainment of 
the SO2 standard.

VII. What actions are being proposed for the Hillsborough-Polk Area?

    Regarding the Hillsborough-Polk Area and in accordance with the 
CAA, EPA proposes to: (1) Approve and incorporate the SO2 
permit limits and associated compliance and monitoring parameters for 
Mosaic New Wales and Bartow into the SIP; (2) approve the base-year 
emissions inventory pursuant to Clean Air Act (CAA or Act) section 
172(c)(3) for the Hillsborough-Polk Area and incorporate it into the 
SIP; (3) concur with Florida's certification pursuant to CAA section 
172(c)(5) that its existing NNSR requirements apply to the 
Hillsborough-Polk Area; (4) determine that the air quality modeling 
submitted by the State demonstrates that the Hillsborough-Polk Area 
will have attained the 2010 SO2 NAAQS as a result of 
compliance with the multi-unit permit limits at Mosaic New Wales and 
Bartow; (5) approve Florida's plan for maintaining the 2010 1-hour 
SO2

[[Page 47221]]

NAAQS in the Hillsborough-Polk Area through 2032 and incorporate it 
into the SIP pursuant to section 175A of the CAA; and (6) redesignate 
the Hillsborough-Polk Area to attainment for the 2010 1-hour 
SO2 NAAQS. Because attainment of the SO2 NAAQS is 
dependent on making the multi-unit permit limits and associated 
compliance and monitoring parameters for Mosaic New Wales and Bartow 
permanent and enforceable measures, EPA cannot take final action on 
items 4-7, above, unless it finalizes its proposal to approve and 
incorporate these caps and parameters into the SIP.

A. What is EPA's analysis of Florida's base-year inventory for the 
Hillsborough-Polk Area?

    States are required under section 172(c)(3) of the CAA to develop 
comprehensive, accurate, and current inventories of actual emissions 
from all sources of the relevant pollutant or pollutants in the 
nonattainment area. These inventories provide a detailed accounting of 
all emissions and emission sources by precursor or pollutant. In 
addition, these inventories are used in air quality modeling to 
demonstrate that attainment of the NAAQS is as expeditious as 
practicable. The SO2 Nonattainment Area Guidance states that 
the emissions inventory should be consistent with the Air Emissions 
Reporting Requirements (AERR) at subpart A to 40 CFR part 51.\17\ The 
SO2 Nonattainment Area Guidance notes that the base-year 
inventory should include all sources of SO2 in the 
nonattainment area as well as any sources located outside the 
nonattainment area which may affect attainment in the area.
---------------------------------------------------------------------------

    \17\ The AERR covers federal reporting requirements for states 
to submit emissions inventories for criteria pollutants to EPA's 
Emission Inventory System. EPA uses these submittals, along with 
other data sources, to build the National Emission Inventory (NEI).
---------------------------------------------------------------------------

    Florida elected to use 2017 as the base year. To develop the base-
year emission inventory, Florida reviewed and compiled county-level 
actual SO2 emissions for all source categories (i.e., point, 
area, and mobile (nonroad and onroad)) in Hillsborough and Polk 
Counties and then utilized county and partial county nonattainment area 
population and land use data to determine estimated SO2 
emission inventories for sources of SO2 in the Hillsborough-
Polk Area. Emissions from Mosaic New Wales, the largest point source of 
SO2 in the Area, as well as nearby Mosaic Bartow, a point 
source located outside of the Area, were included in the inventory.
    Pursuant to Florida's SIP-approved regulations at Rule 62-210.370, 
F.A.C., paragraph (3), FDEP collects annual operating reports (AORs). 
Florida used these AORs to satisfy the AERR and to develop the base 
year inventory for actual emissions for point sources. FDEP utilized 
EPA's 2014 NEI, Version 2 to obtain estimates of the area and nonroad 
sources. For onroad mobile source emissions, FDEP utilized EPA's Motor 
Vehicle Emissions Simulator (MOVES2014). A more detailed discussion of 
the emissions inventory development for the Hillsborough-Polk Area can 
be found in Florida's February 15, 2019, draft SIP submittal.
    Table 3, below, shows the level of emissions in the Hillsborough-
Polk Area for the 2017 base year by emissions source category. The 
point source category includes 2017 emissions from the Mosaic New Wales 
and Mosaic Bartow AORs (6,877 tons and 4,001 tons, respectively). Area 
and nonroad emissions are based on 2014 NEI data for Hillsborough 
County and Polk County. Florida projected the 2014 emissions for the 
area and nonroad categories to 2017 based on the increase in the 
Hillsborough County and Polk County population from 2014 to 2017, and 
then allocated to the Hillsborough-Polk Area based on the Area's 
fraction of land area within each county. Florida estimated onroad 
emissions for the area using MOVES2014a and then allocated them to the 
Hillsborough-Polk Area based on the Area's fraction of land area within 
each county.

                                       Table 3--2017 Base-Year Emissions Inventory for the Hillsborough-Polk Area
                                                                         [tons]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                Year                                      Point             Area           Nonroad           Onroad           Total
--------------------------------------------------------------------------------------------------------------------------------------------------------
2017...............................................................          10,888            16.42             0.31             1.34        10,906.07
--------------------------------------------------------------------------------------------------------------------------------------------------------

    EPA has evaluated Florida's 2017 base-year emissions inventory for 
the Hillsborough-Polk Area and has made the preliminary determination 
that this inventory was developed consistent with EPA's guidance. 
Therefore, pursuant to section 172(c)(3), EPA is proposing to approve 
Florida's 2017 base-year emissions inventory for the Hillsborough-Polk 
Area and incorporate it into the SIP.

B. What is EPA's analysis of Florida's NNSR SIP for the Hillsborough-
Polk Area?

    CAA section 172(c)(5) requires source permits for the construction 
and operation of new and modified major stationary sources anywhere in 
a nonattainment area. In its February 15, 2019, draft SIP revision, 
Florida certifies that it has a SIP-approved NNSR permitting program, 
outlined in Chapters 62-210 and 62-212, F.A.C., to address any new 
major stationary sources or source modifications in the Hillsborough-
Polk Area. The SIP-approved program applies to nonattainment areas for 
all NAAQS, including the 2010 1-hour SO2 standard. Florida 
also states that it is unaware of and does not anticipate any future 
development within the Area that would increase SO2 
emissions. EPA has previously approved Florida's SIP-approved NNSR 
program, including the NNSR regulation at 62-212.500, F.A.C.,\18\ and 
is therefore proposing to concur with Florida's section 172(c)(5) 
certification that its program requires NNSR in the Hillsborough Polk 
Area for so long as the Area is designated nonattainment.\19\
---------------------------------------------------------------------------

    \18\ EPA last modified the SIP-approved version of this rule on 
June 27, 2008. See 73 FR 36435.
    \19\ As discussed in section VII.C.ii.A.2.a, below, EPA has a 
longstanding interpretation that because NNSR is replaced by 
Prevention of Significant Deterioration (PSD) permitting upon 
redesignation, nonattainment areas seeking redesignation to 
attainment need not have a fully approved part D NNSR program in 
order to be redesignated. See Nichols Memorandum. Nonetheless, EPA 
is proposing to concur with the State's certification.
---------------------------------------------------------------------------

C. What is EPA's analysis of the redesignation request and SIP revision 
for the Hillsborough-Polk Area?

    The five redesignation criteria provided under CAA section 
107(d)(3)(E) are discussed in greater detail for the Hillsborough-Polk 
Area in the following paragraphs.

[[Page 47222]]

i. Criterion (1)--The Administrator Determines That the Area Has 
Attained the NAAQS
    For redesignating a nonattainment area to attainment, the CAA 
requires EPA to determine that the area has attained the applicable 
NAAQS (CAA section 107(d)(3)(E)(i)). As discussed in section VIII.A of 
the SO2 Nonattainment Area Guidance, there are generally two 
components needed to support an attainment determination for 
SO2, which should be considered interdependently.\20\ The 
first component relies on air quality monitoring data. For 
SO2, any available monitoring data would need to indicate 
that all monitors in the affected area are meeting the standard as 
stated in 40 CFR 50.17 using data analysis procedures specified in 40 
CFR part 50, Appendix T. The second component relies on air quality 
modeling data. If there are no air quality monitors located in the 
affected area, or there are air quality monitors located in the area, 
but analyses show that none of the monitors are located in the area of 
maximum concentration,\21\ then air quality dispersion modeling will 
generally be needed to estimate SO2 concentrations in the 
area. Such dispersion modeling should be conducted to estimate 
SO2 concentrations throughout the nonattainment area using 
actual emissions and meteorological information for the most recent 
three calendar years. However, EPA may also make determinations of 
attainment based on the modeling from the attainment demonstration \22\ 
for the applicable SIP for the affected area, eliminating the need for 
separate actuals-based modeling to support a redesignation request. A 
demonstration that the control strategy in the SIP has been fully 
implemented (compliance records demonstrating that the control measures 
have been implemented as required by the approved SIP) would also be 
relevant for making the determination, and as noted above, Florida is 
providing emissions data to demonstrate compliance with the 
SO2 permit limits in its final SIP submittal. Areas which 
were designated nonattainment based on modeling will generally not be 
redesignated to attainment unless an acceptable modeling analysis 
indicates attainment. See 1992 Calcagni Memorandum.
---------------------------------------------------------------------------

    \20\ SO2 is primarily a localized, source-specific 
pollutant, and therefore, SO2 control measures are, by 
definition, based on what is directly and quantifiably necessary to 
attain the NAAQS.
    \21\ See section VIII.A of the SO2 Nonattainment Area 
Guidance.
    \22\ Florida submitted the modeling analysis for the 
Hillsborough-Polk and Mulberry Areas in support of its redesignation 
requests and as part of its SIP revision containing permit limits 
for Mosaic Bartow and Mosaic New Wales. Although this modeling 
analysis is not considered part of an ``attainment demonstration'' 
or ``nonattainment SIP'' pursuant to section 172 of the CAA, the 
portion of the SO2 Nonattainment Area Guidance regarding 
the use of modeling summarized in this section of the notice is 
applicable given the similarities between the submitted analysis and 
a modeling analysis under a section 172 ``attainment 
demonstration.''
---------------------------------------------------------------------------

    As discussed above, Florida's December 1, 2017, SIP revision, as 
modified through its February 15, 2019, draft SIP revision, contains a 
modeling analysis to demonstrate that the Area will attain the 2010 1-
hour standard as a result of compliance with the comparably stringent 
24-hour SO2 emissions caps at Mosaic New Wales and Mosaic 
Bartow. When EPA designated the Hillsborough-Polk Area as a 
nonattainment area for the 2010 1-hour SO2 NAAQS, EPA 
determined that Mosaic New Wales was the primary cause of the 2010 1-
hour SO2 NAAQS violations in the Hillsborough-Polk Area. 
However, Florida included nearby Mosaic Bartow in its modeling because 
it determined that emissions from Mosaic Bartow also had the potential 
to contribute to elevated concentrations within the Hillsborough-Polk 
Area.
    Because there are no air quality monitors located in the 
Hillsborough-Polk Area, EPA's proposed approval of Florida's draft 
redesignation and maintenance plan SIP for the Hillsborough-Polk Area 
is based on this modeled demonstration and related information. Details 
regarding the modeling analysis are summarized in the following 
paragraphs. A more detailed discussion of FDEP's modeling, including 
changes in the February 19, 2019, draft SIP revision, can be found in 
EPA's Air Modeling TSD.
    FDEP's modeling analysis was developed in accordance with EPA's 
Guideline on Air Quality Models (Modeling Guideline) \23\ and the 
SO2 Nonattainment Area Guidance, and was prepared using 
EPA's preferred dispersion modeling system--the American Meteorological 
Society/Environmental Protection Agency Regulatory Model (AERMOD)--
consisting of the AERMOD (version 18081) model and multiple data input 
preprocessors as described below. FDEP used regulatory default options 
and the rural land use dispersion option in the AERMOD modeling.
---------------------------------------------------------------------------

    \23\ See 40 CFR part 51 Appendix W (EPA's Guideline on Air 
Quality Models) (January 17, 2017) located at https://www3.epa.gov/ttn/scram/appendix_w/2016/AppendixW_2017.pdf.
---------------------------------------------------------------------------

    The pre-processors AERMET (version 16216) and AERMINUTE (version 
14337) were used to process five years (i.e., 2012-2016) of 1-minute 
meteorological data from the Winter Haven Municipal Airport National 
Weather Service (NWS) surface level site, based on FDEP's land use 
classifications, in combination with twice daily upper-air 
meteorological information from the Ruskin, FL NWS station. The Winter 
Haven Municipal Airport is located approximately 38 km northwest from 
the Hillsborough-Polk Area.
    The AERMOD pre-processor AERMAP (version 18081) was used to 
generate terrain inputs for the receptors, based on a digital elevation 
mapping database from the National Elevation Dataset developed by the 
U.S. Geological Survey. FDEP used AERSURFACE to generate direction-
specific land-use surface characteristics for the modeling.
    The stack heights used in the modeling meet the Good Engineering 
Practice stack height criteria, and the Building Profile Input Program 
for Plume Rise Model Enhancements preprocessor was used to generate 
direction-specific building downwash parameters. FDEP developed two 
overlapping Cartesian receptor grids to fully encompass the entire 
nonattainment area and the unclassifiable area, with 100-meter (m) 
spacing out to 2.5 km from Mosaic New Wales and Mosaic Bartow, 200 m 
spacing from 2.5 km to 5 km, and 500 m spacing from 5 km to 7.5 km from 
the facilities, to ensure maximum concentrations were captured in the 
analysis.
    FDEP selected a background SO2 concentration based on 
monitoring data from the Sydney monitor (AQS ID: 12-057-3002), for the 
period January 2014 to December 2016. The monitor is approximately 23 
km from Mosaic New Wales and 31 km from Mosaic Bartow. The background 
concentration from this ambient air monitor is used to account for 
SO2 impacts from all sources that are not specifically 
included in the AERMOD modeling analysis. The ambient monitoring data 
was obtained from the Florida Air Monitoring and Assessment System. Due 
to its close proximity to the modeled facilities, monitored 
concentrations at this station are strongly influenced by their 
emissions. As a result, and as allowed by EPA's Modeling Guideline, the 
data were filtered to remove measurements where the wind direction 
could transport pollutants from these facilities to the monitor. More 
specifically, the data were filtered to remove measurements where 
hourly wind directions were between 85[deg] to 175[deg]. FDEP elected 
to use a temporally

[[Page 47223]]

varying approach, based on the 99th percentile monitored concentrations 
by hour of day and season or month. The resulting temporally varying 
background concentration ranged from 0.67-7.33 ppb.
    The State used the emissions caps for each of the SO2 
emissions units at Mosaic New Wales and Mosaic Bartow in the modeling 
demonstration. As discussed in Section VI, FDEP's construction permits 
require Mosaic New Wales to comply with a 1,090 lb/hr SO2 
permit limit for its five SAPs and Mosaic Bartow to comply with a 1,100 
lb/hr for its three SAPs, each on a 24-hour block average, no later 
than August 31, 2019. To determine the level of these permit limits, 
the State initially performed exploratory modeling, consisting of over 
300 AERMOD modeling runs, to determine the CEVs for Mosaic New Wales 
and Mosaic Bartow on an hourly basis. This modeling was performed to 
determine the highest aggregate hourly emission rate that, regardless 
of its distribution among any combination of SAPs at the facilities, 
would result in modeled concentrations at or below the level of the 1-
hour NAAQS (i.e., the CEV). The analysis resulted in CEVs of 1,118 lb/
hr and 1,163 lb/hr for Mosaic New Wales and Mosaic Bartow, 
respectively. Following the procedures in EPA's SO2 
Nonattainment Area Guidance, Florida calculated comparably stringent 
24-hour emissions caps using adjustment factors calculated by the ratio 
of each source's historic 99th percentile one-hour average emissions 
rate to its 99th percentile longer-term average emissions rate, which 
resulted in 24-hour adjusted emission caps of 1,100 lb/hr for New Wales 
and 1,138 lb/hr for Bartow. The details of the adjustment factor 
calculation are provided in the LTA TSD for this action. To provide for 
a margin of safety in the final modeling demonstration, Florida 
slightly lowered the 24-hour adjusted emission caps to establish final 
multi-unit permit limits of 1,090 lb/hr and 1,100 lb/hr for New Wales 
and Bartow, respectively. For the final modeling run to show compliance 
with the NAAQS, Florida applied the adjustment factors to back-
calculate 1-hour emission rates (1,108 lb/hr for New Wales and 1,124 
lb/hr for Bartow) from the final 24-hour multi-unit permit limits of 
1,090 lb/hr and 1,100 lb/hr for New Wales and Bartow, respectively.
    Table 4 shows that the maximum modeled 99th percentile daily 
maximum 1-hour SO2 concentration averaged across all five 
years of meteorological data (2012-2016) is less than or equal to the 
2010 1-hour SO2 NAAQS of 75 ppb using the in 1-hour 
equivalent emission rates.

    Table 4--Maximum Modeled 99th Percentile Daily Maximum 1-Hour SO2 Impacts in the Hillsborough-Polk Area,
                                           Micrograms per Cubic Meter
----------------------------------------------------------------------------------------------------------------
                                   Maximum predicted
         Averaging time                 impact            Background             Total             SO2 NAAQS
----------------------------------------------------------------------------------------------------------------
1-hour..........................  186.94 (71.4 ppb).  7.84 (3 ppb)......  194.74 (74.4 ppb).  196.4 (75 ppb).
----------------------------------------------------------------------------------------------------------------

    The final modeling resulted in a highest predicted 99th percentile 
daily maximum 1-hour concentration of 74.4 ppb with no modeled 
violations of the 1-hour SO2 NAAQS in ambient air locations 
in the Hillsborough-Polk Area or in the Mulberry Area. The details of 
the modeling are provided EPA's Air Modeling TSD for this action. EPA 
believes that the modeled demonstration described above is consistent 
with CAA requirements, EPA's Modeling Guideline, and the SO2 
Nonattainment Area Guidance. Therefore, EPA proposes to determine that 
the air quality modeling and related information that will be submitted 
by the State in its final submission (consistent with the current 
proposed SIP) demonstrates that the Hillsborough-Polk Area will have 
attained the 2010 1-hour SO2 NAAQS as a result of compliance 
with the permit limits at Mosaic New Wales and Mosaic Bartow. EPA 
cannot take final action to determine that the Area has attained the 
NAAQS unless it receives the final SIP submittal containing that 
information and finalizes its proposal to approve and incorporate these 
permit limits, associated compliance and monitoring parameters, and 
other related information into the SIP.
ii. Criterion (2)--The Administrator Fully Approves the Applicable 
Implementation Plan for the Area Under Section 110(k); and Criterion 
(5)--Florida Has Met All Applicable Requirements Under Section 110 and 
Part D of Title I of the CAA
    For redesignating a nonattainment area to attainment, the CAA 
requires EPA to determine that the state has met all applicable 
requirements under section 110 and part D of title I of the CAA (CAA 
section 107(d)(3)(E)(v)) and that the state has a fully approved SIP 
under section 110(k) for the area (CAA section 107(d)(3)(E)(ii)). EPA 
proposes to find that Florida has met all applicable SIP requirements 
for the Hillsborough-Polk Area under section 110 of the CAA (general 
SIP requirements) for purposes of redesignation. Additionally, EPA 
proposes to find that the Florida SIP satisfies the criterion that it 
meets applicable SIP requirements for purposes of redesignation under 
part D of title I of the CAA in accordance with section 
107(d)(3)(E)(v). Further, EPA proposes to determine that the SIP is 
fully approved with respect to all requirements applicable for purposes 
of redesignation in accordance with section 107(d)(3)(E)(ii). In making 
these proposed determinations, EPA ascertained which requirements are 
applicable to the Area and, if applicable, that they are fully approved 
under section 110(k). SIPs must be fully approved only with respect to 
requirements that were applicable prior to submittal of the complete 
redesignation request.
A. The Hillsborough-Polk Area Has Met All Applicable Requirements Under 
Section 110 and Part D of the CAA
1. General SIP Requirements
    General SIP elements and requirements are delineated in section 
110(a)(2) of title I, part A of the CAA. These requirements include, 
but are not limited to, the following: Submittal of a SIP that has been 
adopted by the state after reasonable public notice and hearing; 
provisions for establishment and operation of appropriate procedures 
needed to monitor ambient air quality; implementation of a source 
permit program; provisions for the implementation of part C 
requirements (Prevention of Significant Deterioration (PSD)) and 
provisions for the implementation of part D requirements (NNSR permit 
programs); provisions for air pollution modeling; and provisions for 
public and local agency participation in planning and emission control 
rule development.
    Section 110(a)(2)(D) requires that SIPs contain certain measures to 
prevent

[[Page 47224]]

sources in a state from significantly contributing to air quality 
problems in another state. To implement this provision, EPA has 
required certain states to establish programs to address the interstate 
transport of air pollutants. The section 110(a)(2)(D) requirements for 
a state are not linked with a particular nonattainment area's 
designation and classification in that state. EPA believes that the 
requirements linked with a particular nonattainment area's designation 
and classifications are the relevant measures to evaluate in reviewing 
a redesignation request. The transport SIP submittal requirements, 
where applicable, continue to apply to a state regardless of the 
designation of any one particular area in the state. Thus, EPA does not 
believe that the CAA's interstate transport requirements should be 
construed to be applicable requirements for purposes of redesignation.
    In addition, EPA believes that other section 110(a)(2) elements 
that are neither connected with nonattainment plan submissions nor 
linked with an area's attainment status are not applicable requirements 
for purposes of redesignation. The area will still be subject to these 
requirements after the area is redesignated. The section 110(a)(2) and 
part D requirements which are linked with a particular area's 
designation and classification are the relevant measures to evaluate in 
reviewing a redesignation request. This approach is consistent with 
EPA's existing policy on applicability (i.e., for redesignations) of 
conformity and oxygenated fuels requirements, as well as with section 
184 ozone transport requirements. See Reading, Pennsylvania, proposed 
and final rulemakings (61 FR 53174-53176, October 10, 1996), (62 FR 
24826, May 7, 2008); Cleveland-Akron-Loraine, Ohio, final rulemaking 
(61 FR 20458, May 7, 1996); and Tampa, Florida, final rulemaking at (60 
FR 62748, December 7, 1995). See also the discussion on this issue in 
the Cincinnati, Ohio, redesignation (65 FR 37890, June 19, 2000), and 
in the Pittsburgh, Pennsylvania, redesignation (66 FR 50399, October 
19, 2001). Nonetheless, EPA has approved Florida's SIP revisions 
related to the section 110 requirements for the 2010 SO2 
NAAQS, with the exception of the interstate transport elements at 
section 110(a)(2)(D)(i)(I). See 81 FR 67179 (September 30, 2016).
2. Title I, Part D, Applicable SIP Requirements
    Subpart 1 of part D, comprised of CAA sections 171-179B, sets forth 
the basic nonattainment requirements applicable to all nonattainment 
areas. All areas that were designated nonattainment for the 
SO2 NAAQS were designated under Subpart 1 of the CAA in 
accordance with the deadlines in Subpart 5. For purposes of evaluating 
this redesignation request, the applicable Subpart 1 SIP requirements 
are contained in section 172(c)(1)-(9), section 176, and sections 191 
and 192. A thorough discussion of the requirements contained in 
sections 172(c) can be found in the General Preamble for Implementation 
of Title I. See 57 FR 13498 (April 16, 1992).
a. Subpart 1 Section 172 Requirements
    Section 172 requires states with nonattainment areas to submit 
plans providing for timely attainment and meeting a variety of other 
requirements. EPA's longstanding interpretation of the attainment-
related nonattainment planning requirements of section 172 is that once 
an area is attaining the NAAQS, those requirements are not 
``applicable'' for purposes of CAA section 107(d)(3)(E)(ii) and 
therefore need not be approved into the SIP before EPA can redesignate 
the area. In the 1992 General Preamble for Implementation of Title I, 
EPA set forth its interpretation of applicable requirements for 
purposes of evaluating redesignation requests when an area is attaining 
a standard. See 57 FR 13498, 13564 (April 16, 1992). EPA noted that the 
requirements for RFP and other measures designed to provide for 
attainment do not apply in evaluating redesignation requests because 
those nonattainment planning requirements ``have no meaning'' for an 
area that is attaining the standard. Id. This interpretation was also 
set forth in the Calcagni Memo. EPA's understanding of section 172 also 
forms the basis of its Clean Data Policy, articulated with regard to 
the 2010 1-hour SO2 NAAQS in the SO2 
Nonattainment Area Guidance, which suspends a state's obligation to 
submit most of the attainment planning requirements that would 
otherwise apply. Therefore, these section 172(c) nonattainment planning 
requirements are not applicable for purposes of evaluating Florida's 
redesignation request if EPA finalizes its proposal to incorporate the 
permit limits and associated compliance and monitoring parameters into 
the SIP once they become enforceable at the state level on August 31, 
2019. Specifically, the RACT/RACM requirement under 172(c)(1); the RFP 
requirement under section 172(c)(2), which is defined as progress that 
must be made toward attainment; the requirement under section 172(c)(6) 
that the SIP contain control measures necessary to provide for 
attainment of the standard; and the requirement to submit section 
172(c)(9) contingency measures, which are measures to be taken if the 
area fails to make reasonable further progress to attainment, would not 
be applicable.
    Section 172(c)(3) requires submission for approval of a 
comprehensive, accurate, and current inventory of actual emissions. As 
discussed in Section VII.A, EPA is proposing to approve Florida's base-
year emissions inventory for the Hillsborough-Polk Area.
    Section 172(c)(4) requires the identification and quantification of 
allowable emissions for major new and modified stationary sources to be 
allowed in an area, and section 172(c)(5) requires source permits for 
the construction and operation of new and modified major stationary 
sources anywhere in the nonattainment area. EPA has a longstanding 
interpretation that because NNSR is replaced by PSD upon redesignation, 
nonattainment areas seeking redesignation to attainment need not have a 
fully approved part D NNSR program in order to be redesignated. See 
Nichols Memorandum. Florida currently has a fully-approved PSD and part 
D NNSR program in place in Chapters 62-204, 62-210, and 62-212 of the 
Florida Administrative Code. Florida's PSD program will become 
effective in the Area upon redesignation to attainment. Nonetheless, as 
discussed above, Florida has certified that its SIP-approved NNSR 
program meets the requirements of section 172(c)(5) for the 
Hillsborough-Polk Area and EPA is proposing to concur with that 
certification.
    Section 172(c)(7) requires the SIP to meet the applicable 
provisions of section 110(a)(2). As noted above, EPA believes that 
Florida's SIP meets the requirements of section 110(a)(2) applicable 
for purposes of redesignation.
    Finally, section 172(c)(8) allows a state to use equivalent 
modeling, emission inventory, and planning procedures if such use is 
requested by the state and approved by EPA. Florida has not requested 
the use of equivalent techniques under section 172(c)(8).
b. Subpart 1 Section 176--Conformity Requirements
    Section 176(c) of the CAA requires states to establish criteria and 
procedures to ensure that federally supported or funded projects 
conform to the air quality planning goals in the applicable SIP. The 
requirement to determine conformity applies to

[[Page 47225]]

transportation plans, programs, and projects that are developed, 
funded, or approved under title 23 of the United States Code (U.S.C.) 
and the Federal Transit Act (transportation conformity) as well as to 
all other federally supported or funded projects (general conformity). 
State transportation conformity SIP revisions must be consistent with 
federal conformity regulations relating to consultation, and 
enforceability that EPA promulgated pursuant to its authority under the 
CAA.
    EPA believes that it is reasonable to interpret the conformity SIP 
requirements \24\ as not applying for purposes of evaluating the 
redesignation request under section 107(d) because state conformity 
rules are still required after redesignation and federal conformity 
rules apply where state rules have not been approved. See Wall v. EPA, 
265 F.3d 426 (upholding this interpretation) (6th Cir. 2001); See 60 FR 
62748 (December 7, 1995). Furthermore, due to the relatively small, and 
decreasing, amounts of sulfur in gasoline and on-road diesel fuel, 
EPA's transportation conformity rules provide that they do not apply to 
SO2 unless either the EPA Regional Administrator or the 
director of the state air agency has found that transportation-related 
emissions of SO2 as a precursor are a significant 
contributor to a SO2 or fine particulate matter 
(PM2.5) nonattainment problem, or if the SIP has established 
an approved or adequate budget for such emissions as part of the RFP, 
attainment, or maintenance strategy. See 40 CFR 93.102(b)(1), (2)(v); 
SO2 Nonattainment Area Guidance. Neither of these conditions 
have been met; therefore, EPA's transportation conformity rules do not 
apply to SO2 for the Area. For these reasons, EPA proposes 
to find that Florida has satisfied all applicable requirements for 
purposes of redesignation of the Hillsborough-Polk Area under section 
110 and part D of title I of the CAA.
---------------------------------------------------------------------------

    \24\ CAA section 176(c)(4)(E) requires states to submit 
revisions to their SIPs to reflect certain federal criteria and 
procedures for determining transportation conformity. Transportation 
conformity SIPs are different from the motor vehicle emission 
budgets that are established in control strategy SIPs and 
maintenance plans.
---------------------------------------------------------------------------

B. The Hillsborough-Polk Area Has a Fully Approved Applicable SIP Under 
Section 110(k) of the CAA

    EPA has fully approved the applicable Florida SIP for the 
Hillsborough-Polk Area under section 110(k) of the CAA for purposes of 
redesignation. EPA may rely on prior SIP approvals in approving a 
redesignation request (see 1992 Calcagni Memorandum at p. 3, 
Southwestern Pennsylvania Growth Alliance v. Browner, 144 F.3D 984, 
989-90 (6th Cir. 1998); Wall, 265 F.3d 426) plus any additional 
measures it may approve in conjunction with a redesignation action. See 
68 FR 25426 (May 12, 2003) and citations therein.
Criterion (3)--The Air Quality Improvement in the Hillsborough-Polk 
Area is due to Permanent and Enforceable Reductions in Emissions 
Resulting From Implementation of the SIP and Applicable Federal Air 
Pollution Control Regulations and Other Permanent and Enforceable 
Reductions
    For redesignating a nonattainment area to attainment, the CAA 
requires EPA to determine that the air quality improvement in the area 
is due to permanent and enforceable reductions in emissions resulting 
from implementation of the SIP, applicable Federal air pollution 
control regulations, and other permanent and enforceable reductions 
(CAA section 107(d)(3)(E)(iii)). As discussed above, EPA proposes to 
determine that the modeled attainment in the Hillsborough-Polk Area 
will be due to emission reductions resulting from compliance with the 
SO2 permit limits at Mosaic New Wales and Mosaic Bartow. 
These limits will become permanent and enforceable measures if EPA 
finalizes its proposal to approve and incorporate them into the SIP. 
See section VI, above, for more discussion on these permit limits, the 
permit conditions proposed for approval and incorporation into the SIP, 
and the emissions reductions resulting from the limits.
Criterion (4)--The Hillsborough-Polk Area Has a Fully Approved 
Maintenance Plan Pursuant to Section 175A of the CAA
    For redesignating a nonattainment area to attainment, the CAA 
requires EPA to determine that the area has a fully approved 
maintenance plan pursuant to section 175A of the CAA. See CAA section 
107(d)(3)(E)(iv). In conjunction with its request to redesignate the 
Hillsborough-Polk Area to attainment for the 2010 1-hour SO2 
NAAQS, Florida submitted a draft SIP revision to provide for the 
maintenance of the 2010 1-hour SO2 NAAQS for at least 10 
years after the effective date of redesignation to attainment. EPA is 
proposing to determine that this maintenance plan meets the 
requirements for approval under section 175A of the CAA; however, EPA 
cannot take final action to approve the maintenance plan unless it 
finalizes its proposal to approve and incorporate the SO2 
permit limits into the SIP.
a. What is required in a maintenance plan?
    Section 175A of the CAA sets forth the elements of a maintenance 
plan for areas seeking redesignation from nonattainment to attainment. 
Under section 175A, the plan must demonstrate continued attainment of 
the applicable NAAQS for at least 10 years after the Administrator 
approves a redesignation to attainment. Eight years after the 
redesignation, the state must submit a revised maintenance plan 
demonstrating that attainment will continue to be maintained for the 10 
years following the initial 10-year period. To address the possibility 
of future NAAQS violations, the maintenance plan must contain 
contingency measures as EPA deems necessary to assure prompt correction 
of any future 2010 1-hour SO2 violations. The 1992 Calcagni 
Memorandum provides further guidance on the content of a maintenance 
plan, explaining that a maintenance plan should address five 
requirements: The attainment emissions inventory; maintenance 
demonstration; monitoring; verification of continued attainment; and a 
contingency plan. As is discussed more fully below, EPA is proposing to 
determine that Florida's maintenance plan includes all the necessary 
components and is thus proposing to approve it as a revision to the 
Florida SIP.
b. Attainment Emissions Inventory
    An attainment inventory identifies a level of emissions in the area 
that is sufficient to attain the NAAQS. As discussed above, modeled 
attainment of the SO2 NAAQS in the Hillsborough-Polk Area 
will be due to emissions reductions resulting from compliance with the 
SO2 permit limits at Mosaic New Wales and Mosaic Bartow. 
Because the permit limits are not state-enforceable until August 31, 
2019, Florida based its attainment emissions inventory on projected 
emissions from the year after the permit limits become state-
enforceable (i.e., 2020) rather than on actual emission levels that 
reflect complete implementation of the emission reduction measures.\25\
---------------------------------------------------------------------------

    \25\ See Tables 5 and 6 for Mosaic New Wales and Mosaic Bartow, 
respectively, and Appendix L in Florida's draft redesignation 
request and maintenance plan submittal.
---------------------------------------------------------------------------

    The largest point sources of SO2 in or near the 
Hillsborough-Polk Area are Mosaic New Wales and Mosaic Bartow, which 
combined, account for over 99 percent of the SO2 emissions 
in or near

[[Page 47226]]

the Area. Florida projected emissions from both sources to 2020 by 
first analyzing the average utilization factors (i.e., the ratios of 
historical actual to allowable emissions rates) for the SAPs from 2012-
2016. Over this time period, both sources emitted between approximately 
60 percent and 75 percent of each facility's total allowable emissions 
rate. FDEP selected the high end of this range (75 percent) as the 
utilization factor and then applied it to the 2020 allowable emissions 
rate of 4,774 tpy and 4,818 tpy for Mosaic New Wales and Mosaic Bartow, 
respectively, to project 2020 actual emissions for both Mosaic sources. 
Tables 5 and 6 below provide for the historic emissions data (i.e., 
actuals, allowables, and the average percentage of allowables) for both 
facilities as well as 2020 allowables and 2020 projected actuals. The 
projected 2020 actual emissions for Mosaic New Wales and Mosaic Bartow 
are 3,581 tpy and 3,614 tpy, respectively, resulting in total point 
source projected actual emissions of 7,195 tons.

                               Table 5--Mosaic New Wales Historic Emissions and 2020 Projected Actuals Emissions Inventory
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                           2012-2016 Historic emissions                                                        2020 Emissions
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                      Average
                                                             Average annual    Annual allowable    percentage of                       Projected actuals
                           Unit                                actual SO2       SO2 emissions        allowables         Allowables       (75 percent of
                                                               emissions            (tons)            emitted                           2020 allowables)
--------------------------------------------------------------------------------------------------------------------------------------------------------
SAP 1....................................................              1,292              2,172             59.45%              4,774              3,581
SAP 2....................................................              1,517              2,172              69.81  .................  .................
SAP 3....................................................              1,397              2,172              64.32  .................  .................
SAP 4....................................................              1,532              2,117              72.36  .................  .................
SAP 5....................................................              1,394              2,117              65.86  .................  .................
--------------------------------------------------------------------------------------------------------------------------------------------------------


                                Table 6--Mosaic Bartow Historic Emissions and 2020 Projected Actuals Emissions Inventory
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                           2012-2016 Historic Emissions                                                        2020 Emissions
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                      Average
                                                             Average annual    Annual allowable    percentage of                       Projected actuals
                           Unit                                actual SO2       SO2 emissions        allowables         Allowables       (75 percent of
                                                               emissions            (tons)            emitted                           2020 allowables)
--------------------------------------------------------------------------------------------------------------------------------------------------------
SAP 1....................................................              1,315              1,897              69.33              4,818              3,614
SAP 2....................................................              1,308              1,897              68.94  .................  .................
SAP 3....................................................              1,336              1,897              70.43  .................  .................
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Table 7 includes the complete inventory of all source categories 
for the 2020 attainment year. A discussion of the development of the 
2020-2032 projections is found in the next section.

     Table 7--2020 Projected Emissions Inventory by Source Category
------------------------------------------------------------------------
                                                          Projected 2020
                                                           SO2 emissions
                       Source type                            (tons)
 
------------------------------------------------------------------------
Point...................................................           7,195
Area....................................................           16.97
Non-Road................................................            0.32
On-Road.................................................            1.30
                                                         ---------------
  Total.................................................        7,213.59
------------------------------------------------------------------------

c. Maintenance Demonstration
    Maintenance of the 2010 1-hour SO2 standard is 
demonstrated either by showing that future emissions will not exceed 
the level of the attainment emissions inventory year or by modeling to 
show that the future mix of sources and emission rates will not cause a 
violation of the NAAQS. As discussed in the SO2 
Nonattainment Area Guidance, an EPA-approved demonstration of 
attainment that relies on air quality dispersion modeling using maximum 
allowable emissions, such as Florida's modeling, can generally be 
expected to demonstrate that the standard will be maintained for the 
requisite 10 years and beyond without regard to any changes in 
operation rate of the pertinent sources that do not involve increases 
in maximum allowable emissions.\26\ EPA believes that the Hillsborough-
Polk Area will continue to maintain the 2010 1-hour SO2 
standard through year 2032 because the relevant sources are required to 
comply with the permit limits that air quality modeling shows will 
maintain the standard.
---------------------------------------------------------------------------

    \26\ See SO2 Nonattainment Area Guidance at p.67.
---------------------------------------------------------------------------

    To evaluate maintenance through 2032 and satisfy the 10-year 
interval required in CAA section 175A, Florida elected to prepare 
projected emissions inventories for 2020-2032. The emissions 
inventories are composed of the following general source categories: 
point, area, non-road mobile, and on-road mobile. The emissions 
inventories were developed consistent with EPA guidance and are 
summarized in Table 8.
    Florida estimated 2020 point source emissions as discussed above 
and held those emissions steady through 2032 because it is not aware of 
and does not anticipate any future development within the Hillsborough-
Polk Area that would increase SO2 emissions. Furthermore, 
following achievement of the emission levels that Florida demonstrated 
yield attainment, actual emissions from Mosaic New Wales and Mosaic 
Bartow must remain at or below these levels.
    Florida estimated on-road mobile emissions utilizing the most 
recent version of EPA's Motor Vehicle Emission Simulator (MOVES2014a). 
The State developed MOVES inputs for the 2017 base year using county-
level traffic modeling from the Florida Department of Transportation 
and vehicle population information from the Florida Department of 
Highway Safety and Motor Vehicles (FLDHSMV). Where county-level data 
was not available, FDEP used MOVES default data. To develop MOVES 
inputs for future years, FDEP calculated the linear trend of vehicle 
population growth using FLDHSMV data from 2008 to 2018 and projected it 
to future years. FDEP apportioned the Hillsborough County

[[Page 47227]]

and Polk County results of the MOVES2014a model runs for each year to 
the Hillsborough-Polk Area by using the fraction of the county land 
area contained within the boundaries of the Hillsborough-Polk Area.\27\
---------------------------------------------------------------------------

    \27\ See Table 3 in Appendix L for summarize land area and 
MOVES2014a data.
---------------------------------------------------------------------------

    Estimates for the projected future emissions inventories for area 
and non-road categories were calculated by multiplying the area and 
non-road 2014 NEI data \28\ by the projected increase in population in 
Hillsborough and Polk Counties in 2020 and each interim year. The 
population data for 2014 and 2017 were obtained from the US Census 
Bureau. Population projections for 2020 through 2032 were developed by 
the Florida Bureau of Economic and Business Research. For years where 
projections were not available, the projections were interpolated.\29\ 
County level emissions were apportioned to the Hillsborough-Polk Area 
using the fraction of the county land area within the Hillsborough-Polk 
Area boundary.
---------------------------------------------------------------------------

    \28\ See Table 5 in Appendix L for summarize 2014 NEI emissions 
data for area and non-road source categories.
    \29\ Population data and projections are summarized in Table 4 
in Appendix L.
---------------------------------------------------------------------------

    Florida compared projected emissions for the final year of the 
maintenance plan (2032) to the 2020 projected actuals emissions 
inventory and compared interim years to the 2020 projected actuals 
inventory to demonstrate continued maintenance of the 2010 1-hour 
SO2 standard. For additional information regarding the 
development of the projected inventories, see Florida's February 15, 
2019, draft SIP submittal.

                                     Table 8--Projected Future Emissions Inventories for the Hillsborough-Polk Area
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                             Projected 2020     Projected 2023     Projected 2026     Projected 2029     Projected 2032
                       Source type                           SO2 emissions      SO2 emissions      SO2 emissions      SO2 emissions      SO2 emissions
                                                                 (tons)             (tons)             (tons)             (tons)             (tons)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Point....................................................              7,195              7,195              7,195              7,195              7,195
Area.....................................................              16.97              17.83              18.66              19.44              20.16
Non-road.................................................               0.32               0.33               0.35               0.37               0.38
On-road..................................................               1.30               1.27               1.22               1.22               1.22
                                                          ----------------------------------------------------------------------------------------------
    Total................................................           7,213.59           7,214.43           7,215.23           7,216.03           7,216.76
--------------------------------------------------------------------------------------------------------------------------------------------------------

    In situations where local emissions are the primary contributor to 
nonattainment, such as the Hillsborough-Polk Area, if the future 
projected emissions in the nonattainment area remain at or below the 
baseline emissions in the nonattainment area, then the related ambient 
air quality standards should not be violated in the future. Florida has 
projected emissions as described previously, and these projections 
indicate that emissions in the Hillsborough-Polk Area will remain at 
nearly the same levels as those in the attainment year inventory for 
the duration of the maintenance plan. While these projections include a 
very small increase in area and nonroad emissions from 2020 to 2032 
(3.25 tons), the increase is negligible when compared to the total 
emissions inventory, and EPA does not believe that this projected 
increase should cause a violation of the 2010 1-hour SO2 
NAAQS through 2032. This belief is supported by the fact that Florida 
does not anticipate any future development within the Hillsborough-Polk 
Area that could potentially increase SO2 emissions and the 
fact that any increases in actual emissions from Mosaic New Wales or 
Mosaic Bartow must remain below their permitted levels. Furthermore, 
any potential future SO2 emissions sources that may locate 
in or near the Area would be required to comply with the FDEP's 
approved NSR permitting programs to ensure that the Area will continue 
to meet the NAAQS.
d. Monitoring Network
    As noted above, the Hillsborough-Polk Area was designated 
nonattainment based on air dispersion modeling; there is no ambient air 
monitor in the Area. Therefore, the maintenance plan does not contain 
provisions for continued operation of air quality monitors to verify 
attainment status. As discussed in the following section, Florida will 
verify continued attainment using emissions data from Mosaic New Wales 
and Mosaic Bartow and an evaluation of air dispersion modeling inputs.
e. Verification of Continued Attainment
    The State of Florida, through FDEP, has the legal authority to 
enforce and implement all measures necessary to attain and maintain the 
NAAQS. Section 403.061(35), Florida Statutes, authorizes the Department 
to ``exercise the duties, powers, and responsibilities required of the 
state under the federal Clean Air Act.'' This includes implementing and 
enforcing all measures necessary to attain and maintain the NAAQS.
    Because there is no ambient air SO2 monitor in the 
Hillsborough-Polk Area, Florida will verify continued attainment of the 
2010 1-hour SO2 standard through an annual review of 
emissions data and air dispersion modeling inputs and assumptions for 
Mosaic New Wales and Mosaic Bartow. Florida will use emissions data 
from the required AOR submittals from both facilities to verify 
continued compliance with the permitted limits used to model attainment 
of the NAAQS in the Area. Actual emissions must remain below permitted 
levels, which will be made permanent and federally-enforceable if EPA 
finalizes its proposal to approve and incorporate the permit limits 
into the SIP.
    Florida will evaluate the inputs and assumptions used to model 
attainment by assessing emissions data and basic air dispersion inputs 
for the Area on an annual basis. Prior to each annual review, FDEP will 
contact EPA to discuss the emissions data and air dispersion modeling 
inputs and assumptions necessary for evaluation. FDEP will verify 
attainment using the emissions data and air dispersion modeling inputs 
and assumptions identified by EPA as a result of coordination with 
FDEP. FDEP anticipates that the inputs and assumptions may include 
stack parameters for all modeled sources; significant changes to land 
use in the area; a limited review of meteorology; changes in operation 
that lead to a temporal or spatial distribution of emissions; onsite 
construction that change building configuration/

[[Page 47228]]

dimensions or add new buildings; changes in fuel that would alter 
emissions; and changes in ambient background concentrations used in the 
cumulative modeling analysis.
    Based on its review of source emissions data and air dispersion 
modeling inputs and assumptions, FDEP will provide an annual report to 
EPA on or before July 1st that certifies whether the Hillsborough-Polk 
Area is continuing to attain the 2010 1-hour SO2 NAAQS. This 
annual report will provide: (1) The status of ongoing compliance with 
the SO2 permit limits for Mosaic New Wales and Mosaic 
Bartow; (2) a review of annual emissions data for these facilities; (3) 
a review of the air dispersion modeling inputs and assumptions 
identified by EPA as a result of coordination with FDEP; (4) a 
certification that there are no changes in the air dispersion modeling 
inputs and assumptions that could result in a modeled violation; and 
(5) all supporting documentation and data evaluated by FDEP to prepare 
its annual report.
    If FDEP certifies that there are no changes in the modeling inputs 
and assumptions that could result in modeled violations, and EPA 
concurs, no additional action or information is necessary to verify 
continued attainment. If FDEP or EPA identifies a change in the 
modeling inputs and assumptions that could cause a modeled violation, 
FDEP, in coordination with EPA, will further evaluate the modeling 
inputs and assumptions and complete this evaluation no later than 30 
days after identifying the changes. If this evaluation continues to 
indicate that a modeled violation could occur, FDEP will conduct air 
dispersion modeling no later than 30 days after completing the 
evaluation. If the revised model does not produce a modeled violation, 
then no additional action or information is necessary to verify 
continued attainment. If the revised model produces a modeled violation 
of the 2010 1-hour SO2 standard within the nonattainment 
area, the State will implement the relevant contingency measures as 
discussed below.
f. Contingency Measures in the Maintenance Plan
    Section 175A of the CAA requires that a maintenance plan include 
contingency measures as EPA deems necessary to assure that the state 
will promptly correct a violation of the NAAQS that occurs after 
redesignation. The maintenance plan should identify the contingency 
measures to be adopted, a schedule and procedure for adoption and 
implementation, and a time limit for action by the state. In cases 
where attainment revolves around compliance of a single source or a 
small set of sources with emissions limits shown to provide for 
attainment, EPA interprets ``contingency measures'' to mean that the 
state agency has a comprehensive program to identify sources of 
violations of the SO2 NAAQS and to undertake aggressive 
follow-up for compliance and enforcement, including expedited 
procedures for establishing enforceable consent agreement pending the 
adoption of revised SIPs.\30\ A state should also identify specific 
indicators to be used to determine when the contingency measures need 
to be implemented. The maintenance plan must include a requirement that 
a state will implement all measures with respect to control of the 
pollutant that were contained in the SIP before redesignation of the 
area to attainment in accordance with section 175A(d).
---------------------------------------------------------------------------

    \30\ See SO2 Nonattainment Area Guidance at p.69. 
FDEP has an active compliance and enforcement program to address 
violations. FDEP will continue to operate this program to identify 
sources of violations of the SO2 NAAQS and to undertake 
an aggressive follow-up for compliance and enforcement, including 
expedited procedures for establishing enforceable consent agreements 
pending the adoption of revised SIPs. FDEP commits to adopt and 
expeditiously implement necessary corrective actions in the event of 
a violation.
---------------------------------------------------------------------------

    The contingency plan included in the maintenance plan contains 
triggers to determine when contingency measures are needed and what 
kind of measures should be used. The Title V operating permits for 
Mosaic New Wales and Mosaic Bartow require the facilities to report any 
non-compliance with permit conditions or limitations.\31\ Upon receipt 
of such a report from Mosaic New Wales and/or Mosaic Bartow that 
identifies noncompliance with the SO2 permit limits, FDEP 
will immediately begin a 30-day evaluation period to diagnose the cause 
of noncompliance. This will be followed by a 30-day consultation period 
with Mosaic New Wales and/or Mosaic Bartow to develop and implement 
operational changes identified during the consultation period to 
prevent any future noncompliance with the SO2 permit limits. 
These changes could include, but would not be limited to, physical or 
operational reduction of production capacity, as appropriate. Any 
necessary changes would be implemented as soon as practicable, with at 
least one measured implemented during the full system audit implemented 
within 18-24 months of the noncompliance with the SO2 permit 
limits, in order to bring the Area into attainment as expeditiously as 
possible.
---------------------------------------------------------------------------

    \31\ This reporting requirement is detailed in Appendix RR2(b) 
and (c) in the Title V permits as follows: ``b. If, for any reason, 
the permittee does not comply with or will be unable to comply with 
any condition or limitation specified in this permit, the permittee 
shall immediately provide the Department with the following 
information: (1) A description of and cause of noncompliance; and 
(2) The period of noncompliance, including dates and times; or, if 
not corrected, the anticipated time the noncompliance is expected to 
continue, and steps being taken to reduce, eliminate, and prevent 
recurrence of the noncompliance. The permittee shall be responsible 
for any and all damaged which may result and may be subject to 
enforcement action by the Department for penalties or for revocation 
of this permit. c. When requested by the Department, the permittee 
shall within a reasonable time furnish any information required by 
law which is needed to determine compliance with the permit. If the 
permittee becomes aware the relevant facts were not submitted or 
were incorrect in the permit application or in any report to the 
Department, such facts or information shall be corrected promptly.'' 
``Immediately'' is defined in Appendix RR(d) as ``the same day, if 
during a workday (i.e., 8:00 a.m.-5:00 p.m.), or the first business 
day after the incident, excluding weekends and holidays.''
---------------------------------------------------------------------------

    FDEP would rely on its authority outlined in Rule 62-4.080, F.A.C., 
which expressly authorizes FDEP to require the permittee to conform to 
new or additional conditions if there is a showing of any change in the 
environment or surrounding conditions that requires a modification to 
conform to applicable air quality standards. Depending on the present 
circumstances, FDEP would exercise this authority to work expeditiously 
with Mosaic New Wales and Mosaic Bartow to make necessary permit 
modifications. If a permit modification is deemed necessary, FDEP would 
issue a final permit within the statutory timeframes in Sections 120 
and 403, Florida Statutes, and any new permit limits required by such a 
permit would be submitted to EPA as a SIP revision.
    If revised air dispersion modeling performed during the 
verification of continued attainment process produces a violation of 
the 2010 1-hour SO2 standard due to changes in modeling 
inputs and assumptions, FDEP will immediately begin a 30-day evaluation 
period to diagnose the cause of the modeled violation, including 
consultation with any emission source(s) that FDEP believes may be a 
cause of the modeled violation. At the completion of this evaluation 
period, FDEP will begin to take necessary measures to remedy the 
modeled violation of the 2010 1-hour SO2 standard, which may 
include mandating physical or operational changes at emission sources. 
Any necessary changes would be implemented as soon as practicable, with 
at least one measure implemented within 18-24 months of the modeled 
violation, in order to bring the area into modeled attainment as 
expeditiously as possible.

[[Page 47229]]

    EPA has preliminarily concluded that the maintenance plan 
adequately addresses the five basic components of a maintenance plan: 
The attainment emissions inventory; maintenance demonstration; 
monitoring; verification of continued attainment; and a contingency 
plan. Therefore, EPA proposes to determine that the maintenance plan 
for the Area meets the requirements of section 175A of the CAA and 
proposes to incorporate the maintenance plan into the Florida SIP. EPA 
cannot take final action to approve the maintenance plan unless it 
finalizes its proposal to approve and incorporate the SO2 
permit limits into the SIP.

VIII. What is EPA's analysis of the redesignation request for the 
Mulberry Area?

A. Background

    On January 9, 2018 (effective April 9, 2018), EPA designated the 
Mulberry Area as unclassifiable for the 2010 1-hour SO2 
NAAQS. See 83 FR 1098. EPA designated the Area as unclassifiable based 
on uncertainty regarding the potential for SO2 emissions 
from Mosaic Bartow to contribute to the Hillsborough-Polk Area. EPA's 
rationale for this designation is outlined in the TSD associated with 
EPA's designation for the Mulberry Area.\32\
---------------------------------------------------------------------------

    \32\ See Chapter 9 of the Technical Support Document for the 
Round 3 Designations for the 2010 1-Hour SO2 NAAQS 
located in the docket for the designation at Docket ID No. EPA-HQ-
OAR-2017-0003-0635.
---------------------------------------------------------------------------

B. Criteria for Redesignating an Area From Unclassifiable to 
Attainment/Unclassifiable

    Section 107(d)(3) of the CAA provides the framework for changing 
the area designations for any NAAQS pollutants. Section 107(d)(3)(A) 
provides that the Administrator may notify the Governor of any state 
that the designation of an area should be revised ``on the basis of air 
quality data, planning and control considerations, or any other air 
quality-related considerations the Administrator deems appropriate.'' 
The Act further provides in section 107(d)(3)(D) that even if the 
Administrator has not notified a state Governor that a designation 
should be revised, the Governor of any state may, on the Governor's own 
motion, submit a request to revise the designation of any area, and the 
Administrator must approve or deny the request.
    When approving or denying a request to redesignate an area, EPA 
bases its decision on the air quality data for the area as well as the 
considerations provided under section 107(d)(3)(A).\33\ For the 1-hour 
SO2 NAAQS, EPA may also base its decision on relevant 
modeling analyses as discussed in section VII.C, above. In keeping with 
section 107(d)(1)(A), areas that are redesignated to attainment/
unclassifiable must meet the requirements for attainment areas and thus 
must meet the relevant NAAQS.\34\ In addition, the area must not 
contribute to ambient air quality in a nearby area that does not meet 
the NAAQS.
---------------------------------------------------------------------------

    \33\ While CAA section 107(d)(3)(E) also lists specific 
requirements for redesignations, those requirements only apply to 
redesignations of nonattainment areas to attainment and, therefore, 
are not applicable in the context of a redesignation of an area from 
unclassifiable to attainment/unclassifiable.
    \34\ Historically, EPA has designated most areas that do not 
meet the definition of nonattainment as ``unclassifiable/
attainment.'' EPA has reversed the order of the label to be 
``attainment/unclassifiable'' to better convey the definition of the 
designation category and so that the category is more easily 
distinguished from the separate unclassifiable category. See, e.g., 
83 FR 1098, 1099 (January 9, 2018) and 83 FR 25776, 25778 (June 4, 
2018). EPA reserves the ``attainment'' category for when EPA 
redesignates a nonattainment area to attainment.
---------------------------------------------------------------------------

C. EPA's Rationale for Proposing To Redesignate the Mulberry Area

    As noted above, EPA designated the Mulberry Area as unclassifiable 
due to uncertainty regarding the potential contribution of emissions 
from Mosaic Bartow to the Hillsborough-Polk Area. After EPA finalized 
the designation, FDEP established permits requiring catalyst 
installation and compliance with the SO2 permit limits for 
Mosaic New Wales and Mosaic Bartow. As discussed above, EPA has 
reviewed the modeling based on CEVs which, when adjusted, provide for 
the 24-hour adjusted emission caps of 1,100 lb/hr and 1,138 lb/hr for 
New Wales and Bartow, respectively. To provide for an additional margin 
of safety in its air dispersion modeling, Florida slightly lowered the 
maximum 24-hour emission caps to establish final multi-unit permit 
limits of 1,090 lb/hr and 1,100 lb/hr for New Wales and Bartow, 
respectively. EPA believes that the modeling results relying on the 
slightly lowered permit limits appropriately characterize the air 
quality in the Mulberry Area and that this modeling demonstrates that 
the Mulberry Area will have attained the 1-hour SO2 standard 
as a result of compliance with these limits at Mosaic New Wales and 
Mosaic Bartow. Therefore, EPA proposes to redesignate the Mulberry Area 
to attainment/unclassifiable for the SO2 NAAQS. EPA cannot 
redesignate the Mulberry Area to attainment/unclassifiable unless it 
finalizes its proposal to approve and incorporate the permit limits and 
associated compliance and monitoring parameters into the SIP.

IX. What is the effect of EPA's proposed actions?

    Approval and incorporation of the Mosaic New Wales and Mosaic 
Bartow permit conditions described in Section VI, above, into the SIP 
would make them permanent and federally enforceable.
    Approval of the base-year emissions inventory would satisfy the 
requirements of CAA section 173(c)(3) for the Hillsborough-Polk Area 
and incorporate that inventory into the SIP. Concurrence with Florida's 
certification that prior EPA rulemaking has approved NNSR rules that 
require NNSR for the Hillsborough-Polk Area for so long as the Area is 
designated nonattainment would satisfy CAA section 173(c)(5).
    Approval of Florida's redesignation request for the Hillsborough-
Polk Area would change the legal designation of the portions of 
Hillsborough and Polk Counties that are within the Hillsborough-Polk 
Area, as found at 40 CFR part 81, from nonattainment to attainment for 
the 2010 1-hour SO2 NAAQS. Approval of Florida's associated 
maintenance plan SIP revision would incorporate a plan for maintaining 
the 2010 1-hour SO2 NAAQS in the Hillsborough-Polk Area 
through 2032 into the SIP.
    Lastly, approval of Florida's redesignation request for the 
Mulberry Area would change the legal designation of the portion of Polk 
County that is within the Mulberry Area, as found at 40 CFR part 81, 
from unclassifiable to attainment/unclassifiable for the 2010 1-hour 
SO2 NAAQS.

X. Incorporation by Reference

    EPA is proposing to include in a final EPA rule regulatory text 
that includes incorporation by reference. In accordance with 
requirements of 1 CFR 51.5, EPA is proposing to incorporate by 
reference into Florida's SIP the following conditions from Permit No. 
1050046-050-AC issued by FDEP to Mosaic Bartow with an effective date 
of July 3, 2017: (1) Section III, Subsection A, Specific Condition 3 
(as administratively corrected by Permit No. 1050046-063-AC with an 
effective date of January 11, 2019); \35\ (2) Section

[[Page 47230]]

III, Subsection A, Specific Condition 4; \36\ and (3) Section III, 
Subsection A, Specific Condition 5.\37\ In accordance with requirements 
of 1 CFR 51.5, EPA is also proposing to incorporate by reference into 
Florida's SIP the following conditions from Permit No. 1050059-106-AC 
issued by FDEP to Mosaic New Wales with an effective date of October 
30, 2017: (1) Section III, Subsection A, Specific Condition 3; \38\ (2) 
Section III, Subsection A, Specific Condition 4 (as administratively 
corrected by Permit No. 1050059-114-AC with an effective date of 
January 11, 2019); \39\ and (3) Section III, Subsection A, Specific 
Condition 5.\40\ EPA has made, and will continue to make, these 
materials generally available through www.regulations.gov and at EPA 
Region 4 office (please contact the person identified in the FOR 
FURTHER INFORMATION CONTACT section of this preamble for more 
information).
---------------------------------------------------------------------------

    \35\ This provision states: ``SO2 Emissions Limit: 
The following emission limit applies to the Sulfuric Acid Plant 
(SAP) Nos. 1, 2, 3, 4 & 5: a. When all five SAPs are in operation 
within the same 24-hour block averaging period, a cap of 1,090 lb 
SO2/hour, 24-hour block average (6:00 a.m. to 6:00 a.m.) 
is applicable; and, b. The cap of 1,090 lb SO2/hour, 24-
hour block average (6:00 a.m. to 6:00 a.m.) applies in scenarios 
when any combination of any number of the SAPs are not in operation 
and when any number of the SAPs are in operation. [Rules 62-4.030, 
General Prohibition, F.A.C. & Rule 62-4.210, Construction Permits, 
F.A.C.; Application No. 1050059-106-AC; and, Administrative Permit 
Correction Application No. 1050059-114-AC.]''
    \36\ This provision states: ``Initial Compliance: These emission 
units shall use certified SO2 CEMS data to demonstrate 
initial compliance with the new SO2 emission limit. 
[Rules 62-4.070(1)&(3), Reasonable Assurance, F.A.C.; and, 
Application Nos. 1050059-103-AC & 1050059-106-AC.]''
    \37\ This provision states: ``Recordkeeping: The permittee shall 
keep records of the initial compliance demonstration. The records 
shall include the SO2 CEMS data along with the sulfuric 
acid production rate (TPH, tons per hour) during the demonstration. 
Any reports shall be prepared in accordance with the applicable 
requirements specified in Appendix D (Common Testing Requirements) 
of this permit. [Rule 62-297.310(10), F.A.C.; and, Application Nos. 
1050059-103-AC & 1050059-106-AC.]''
    \38\ This provision states: ``SO2 Emissions Limit: 
The following emission limit applies to the Sulfuric Acid Plant 
(SAP) Nos. 4, 5 & 6: a. When all five SAPs are in operation within 
the same 24-hour block averaging period, a cap of 1,100 lb 
SO2/hour, 24-hour block average (6:00 a.m. to 6:00 a.m.) 
is applicable; and, b. The cap of 1,100 lb SO2/hour, 24-
hour block average (6:00 a.m. to 6:00 a.m.) applies in scenarios 
when any combination of any number of the SAPs are not in operation 
and when any number of the SAPs are in operation. [Rules 62-4.030, 
General Prohibition, F.A.C. & Rule 62-4.210, Construction Permits, 
F.A.C.; Application No. 1050046-050-AC; and, Administrative Permit 
Correction Application No. 1050046-063-AC.]''
    \39\ This provision states: ``Initial Compliance: These emission 
units shall use certified SO2 CEMS data to demonstrate 
initial compliance with the new SO2 emission limit. 
[Rules 62-4.070(1)&(3), Reasonable Assurance, F.A.C.; and, 
Application No. 1050046-050-AC.]''
    \40\ This provision states: ``Recordkeeping: The permittee shall 
keep records of the initial compliance demonstration. The records 
shall include the SO2 CEMS data along with the sulfuric 
acid production rate (TPH, tons per hour) during the demonstration. 
Any reports shall be prepared in accordance with the applicable 
requirements specified in Appendix D (Common Testing Requirements) 
of this permit. [Rule 62-297.310(10), F.A.C.; and, Application No. 
1050046-050-AC.]''
---------------------------------------------------------------------------

XI. Proposed Actions

    EPA is proposing to approve SIP revisions provided by Florida 
related to the 2010 1-hour SO2 NAAQS. Specifically, EPA is 
proposing to approve Florida's December 1, 2017, SIP revision (as 
supplemented through the February 15, 2019, draft SIP revision) which 
includes SO2 permit limits and associated compliance and 
monitoring provisions for Mosaic New Wales and Mosaic Bartow. The 
December 1, 2017, SIP revision also includes a modeling analysis to 
demonstrate that the Hillsborough-Polk Area will attain the 
SO2 NAAQS as a result of compliance with these permit 
limits.
    EPA is also proposing to approve, through parallel processing, a 
draft February 15, 2019 request to redesignate the Hillsborough-Polk 
Area to attainment for the SO2 NAAQS and associated SIP 
revision containing the State's plan for maintaining attainment of the 
2010 1-hour SO2 standard in that Area. Florida also 
submitted draft SIP revisions on February 15, 2019, to revise the 
modeling analysis in the 2017 SIP revision, provide a base-year 
emissions inventory for the Area, and certify that the Area meets NNSR 
requirements. In addition, EPA is proposing to approve, through 
parallel processing, Florida's draft February 15, 2019 request to 
redesignate the Mulberry Area to attainment/unclassifiable for the 2010 
SO2 NAAQS.
    EPA is proposing to approve these requests and SIP revisions 
because the Agency has made the preliminary determination that they 
meet the requirements of the CAA.

XII. Statutory and Executive Order Reviews

    Under the CAA, redesignation of an area to attainment and the 
accompanying approval of a maintenance plan under section 107(d)(3)(E) 
as well as the redesignation of an area to attainment/unclassifiable 
are actions that affect the status of a geographical area and do not 
impose any additional regulatory requirements on sources beyond those 
imposed by state law. A redesignation to attainment or to attainment/
unclassifiable does not in and of itself create any new requirements, 
but rather results in the applicability of requirements contained in 
the CAA for areas that have been redesignated to attainment or 
attainment/unclassifiable, respectively. Moreover, the Administrator is 
required to approve a SIP submission that complies with the provisions 
of the Act and applicable Federal regulations. See 42 U.S.C. 7410(k); 
40 CFR 52.02(a). Thus, in reviewing SIP submissions, EPA's role is to 
approve state choices, provided that they meet the criteria of the CAA. 
Accordingly, these proposed actions merely propose to approve state law 
as meeting Federal requirements and do not impose additional 
requirements beyond those imposed by state law. For this reason, these 
proposed actions:
     Are not significant regulatory actions subject to review 
by the Office of Management and Budget under Executive Orders 12866 (58 
FR 51735, October 4, 1993) and 13563 (76 FR 3821, January 21, 2011);
     Are not Executive Order 13771 (82 FR 9339, February 2, 
2017) regulatory actions because redesignations and SIP approvals are 
exempted under Executive Order 12866;
     Do not impose information collection burdens under the 
provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
     Are 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.);
     Do not contain any unfunded mandates or significantly or 
uniquely affect small governments, as described in the Unfunded 
Mandates Reform Act of 1995 (Pub. L. 104-4);
     Do not have Federalism implications as specified in 
Executive Order 13132 (64 FR 43255, August 10, 1999);
     Are not economically significant regulatory actions based 
on health or safety risks subject to Executive Order 13045 (62 FR 
19885, April 23, 1997);
     Are not significant regulatory actions subject to 
Executive Order 13211 (66 FR 28355, May 22, 2001);
     Are 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
     Will not have disproportionate human health or 
environmental effects under Executive Order 12898 (59 FR 7629, February 
16, 1994).
    These proposed actions do not apply on any Indian reservation land 
or in any other area where EPA or an Indian tribe has demonstrated that 
a tribe has jurisdiction. In those areas of Indian country, these 
proposed actions do not have tribal implications as specified by 
Executive Order 13175 (65 FR 67249, November 9, 2000), nor will they 
impose substantial direct costs on tribal governments or preempt tribal 
law.

[[Page 47231]]

List of Subjects

40 CFR Part 52

    Environmental protection, Air pollution control, Incorporation by 
reference, Intergovernmental relations, Reporting and recordkeeping, 
Sulfur dioxide.

40 CFR Part 81

    Environmental protection, Air pollution control, National parks, 
Wilderness areas.

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

    Dated: August 27, 2019.
Mary S. Walker,
Regional Administrator, Region 4.
[FR Doc. 2019-19413 Filed 9-6-19; 8:45 am]
 BILLING CODE 6560-50-P