Document ID: EPA-R09-OAR-2020-0589-0001
Agency: epa
Document Type: Proposed Rule
Title: Air Quality State Implementation Plans; Approvals and Promulgations: Arizona; Stationary Sources; New Source Review Updates
Posted Date: 2020-12-23T05:00Z

[Federal Register Volume 85, Number 247 (Wednesday, December 23, 2020)]
[Proposed Rules]
[Pages 83868-83877]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2020-27952]

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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R09-OAR-2020-0589; FRL-10017-39-Region 9]

Air Plan Approval; Arizona; Stationary Sources; New Source Review 
Updates

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: The Environmental Protection Agency (EPA) is proposing to 
approve revisions to the Arizona Department of Environmental Quality's 
(ADEQ) portion of the Arizona State Implementation Plan (SIP). These 
revisions are primarily intended to make corrections to the ADEQ's SIP-
approved rules for the issuance of New Source Review (NSR) permits for 
stationary sources under the Clean Air Act (CAA or Act). This proposed 
action will update the ADEQ's NSR rules in the SIP and correct the 
remaining deficiencies in the ADEQ's NSR program that we identified in 
final EPA rulemaking actions in 2015 and 2016. Additionally, we are 
proposing a finding that the ADEQ's SIP-approved NSR permitting program 
meets requirements for visibility protection for major NSR sources 
under the Act and are proposing to remove Federal Implementation Plans 
(FIPs) related to these requirements. We are seeking comment on our 
proposed action and plan to follow with a final action.

DATES: Comments must be received on or before January 22, 2021.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R09-
OAR-2020-0589 at https://www.regulations.gov. For comments submitted at 
Regulations.gov, follow the online instructions for submitting 
comments. Once submitted, comments cannot be edited or removed from 
Regulations.gov. The EPA may publish any comment received to its public 
docket. Do not submit electronically any information you consider to be 
Confidential Business Information (CBI) or other information the 
disclosure of which disclosure is restricted by statute. Multimedia 
submissions (audio, video, etc.) must be accompanied by a written 
comment. The written comment is considered the official comment and 
should include discussion of all points you wish to make. The EPA will 
generally not consider comments or comment contents located outside of 
the primary submission (i.e. on the web, cloud, or other file sharing 
system). For additional submission methods, please contact the person 
identified in the FOR FURTHER INFORMATION CONTACT section. For the full 
EPA public comment policy, information about CBI or multimedia 
submissions, and general guidance on making effective comments, please 
visit https://www.epa.gov/dockets/commenting-epa-dockets. If you need 
assistance in a language other than English or if you are a person with 
disabilities who needs a reasonable accommodation at no cost to you, 
please contact the person identified in the FOR FURTHER INFORMATION 
CONTACT section.

FOR FURTHER INFORMATION CONTACT: Lisa Beckham, EPA Region IX, 75 
Hawthorne St., San Francisco, CA 94105. By phone: (415) 972-3811 or by 
email at beckham.lisa@epa.gov.

SUPPLEMENTARY INFORMATION: Throughout this document, ``we,'' ``us'' and 
``our'' refer to the EPA.

Table of Contents

I. The State's Submittals
    A. What did the State submit?
    B. Are there other versions of the rules in the Arizona SIP?
    C. What is the purpose of the submittals?
II. The EPA's Evaluation
    A. How is the EPA evaluating the submittals?
    B. Do the submittals meet the evaluation criteria for NSR 
programs?
    C. Evaluation of Rules Requested To Be Removed From the SIP
    D. Approval of Program for Visibility Protection in Class I 
Areas
    E. Do the rules meet the evaluation criteria under Sections 
110(a)(2)(A), 110(a)(2)(E)(i), 110(l), and 193 of the Clean Air Act?
    F. Conclusion
III. Public Comment and Proposed Action
IV. Incorporation by Reference
V. Statutory and Executive Order Reviews

Definitions

    For this document, we are giving meaning to certain words or 
initials as follows:
    (i) The words or initials Act or CAA mean or refer to the Clean Air 
Act, unless the context indicates otherwise.
    (ii) The initials ADEQ mean or refer to the Arizona Department of 
Environmental Quality.
    (iii) The initials ARS mean or refer to the Arizona Revised 
Statutes.
    (iv) The initials CBI mean or refer to confidential business 
information.
    (v) The initials CFR mean or refer to Code of Federal Regulations.
    (vi) The words EPA, we, us or our mean or refer to the United 
States Environmental Protection Agency.
    (vii) The initials FIP mean or refer to Federal Implementation 
Plan.
    (viii) The initials MMBtu/hr mean or refer to million British 
thermal units per hour.
    (ix) The initials NAAQS mean or refer to National Ambient Air 
Quality Standards.
    (x) The initials NESHAP mean or refer to National Emission 
Standards for Hazardous Air Pollutants.
    (xi) The initials NNSR mean or refer to Nonattainment New Source 
Review.
    (xii) The initals NO2 mean or refer to nitrogen dioxide.
    (xiii) The initials NOX mean or refer to oxides of nitrogen.
    (xiv) The initials NSPS mean or refer to New Source Performance 
Statndards.
    (xv) The initials NSR mean or refer to New Source Review.
    (xvi) The initials PM2.5 mean or refer to particulate matter with 
an aerodynamic diameter of less than or equal to 2.5 micrometers (fine 
particulate matter).
    (xvii) The initials PSD mean or refer to Prevention of Significant 
Deterioration.
    (xviii) The initials SIP mean or refer to State Implementation 
Plan.
    (xix) The initials SO2 mean or refer to sulfur dioxide.
    (xx) The words State or Arizona mean the State of Arizona, unless 
the context indicates otherwise.
    (xxi) The initials TSD mean or refer to the technical support 
document for this action, unless the context indicates otherwise.

I. The State's Submittals

A. What did the State submit?

    The ADEQ is the governor's designee for submitting official 
revisions of the Arizona SIP to the EPA. This proposal evaluates three 
SIP revisions submitted by the ADEQ on March 29, 2019,\1\ January 14, 
2020, and July 22, 2020.\2\

[[Page 83869]]

The submittals include several rules and demonstrations related to the 
ADEQ's NSR program.
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    \1\ This submittal was transmitted with a cover letter dated 
March 20, 2019 from Timothy S. Franquist, Director, Air Quality 
Division, ADEQ to Michael Stoker, Regional Administrator, EPA Region 
IX.
    \2\ This submittal was made via the EPA's eSIP submission 
system--State Plan electronic Collaboration System (SPeCS) for 
SIPs--on July 22, 2020. A copy of the submission form is available 
in the docket for this action. Due to an apparent typographical 
error, the cover letter for the submittal was erroneously dated as 
July 21, 2017 rather than July 21, 2020. Additionally, an Excel 
spreadsheet that is part of the submittal but that was not submitted 
through the SPeCS was submitted to the EPA via email on July 21, 
2020. The spreadsheet and transmittal email are also included in the 
docket for this action.
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    Table 1 of this preamble lists the rules addressed by this proposal 
with the dates on which they became effective under State law. The 
ADEQ's January 14, 2020 submittal requested that specific paragraphs 
from certain revised rules be added to the Arizona SIP. The ADEQ's July 
22, 2020 submittal clarifies that the ADEQ requests that the entirety 
of each revised rule (with one exception) be included in the SIP, 
rather than only the selected paragraphs identified in the earlier 
submittal. As such, Table 1 of this preamble reflects the updated rule 
submission request in the July 22, 2020 submittal. The submitted rules 
are from the Arizona Administrative Code, Title 18--Environmental 
Quality, Chapter 2--Department of Environmental Quality--Air Pollution 
Control, Articles 1, 3, and 4.
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    \3\ We note that this rule contains a new provision stating that 
a particular revised subsection, R18-2-101(131)(f), will take effect 
on the effective date of the EPA Administrator's action approving it 
as part of the Arizona SIP. Therefore, the revised version of R18-2-
101(131)(f) would become effective on the effective date of our 
approval of the current submittal of R18-2-101.

                        Table 1--Submitted Rules
------------------------------------------------------------------------
                                                                State
               Rule                          Title            effective
                                                                 date
------------------------------------------------------------------------
R18-2-101, except (20)...........  Definitions.............     \3\ 2/1/
                                                                    2020
R18-2-301........................  Definitions.............     2/1/2020
R18-2-302........................  Applicability;              3/21/2017
                                    Registration; Classes
                                    of Permits.
R18-2-302.01.....................  Source Registration          2/1/2020
                                    Requirements.
R18-2-304........................  Permit Application           2/1/2020
                                    Processing Procedures.
R18-2-306........................  Permit Contents.........    3/21/2017
R18-2-306.01.....................  Permits Containing          3/21/2017
                                    Voluntarily Accepted
                                    Emission Limitations
                                    and Standards.
R18-2-317........................  Facility Changes Allowed     8/7/2012
                                    Without Permit
                                    Revisions--Class I.
R18-2-317.01.....................  Facility Changes that        8/7/2012
                                    Require a Permit
                                    Revision--Class II.
R18-2-317.02.....................  Procedures for Certain       8/7/2012
                                    Changes that Do Not
                                    Require a Permit
                                    Revision--Class II.
R18-2-319........................  Minor Permit Revisions..    3/21/2017
R18-2-320........................  Significant Permit          3/21/2017
                                    Revisions.
R18-2-334........................  Minor New Source Review.     2/1/2020
R18-2-406........................  Permit Requirements for      2/1/2020
                                    Sources Located in
                                    Attainment and
                                    Unclassifiable Areas.
------------------------------------------------------------------------

    On September 29, 2019 and July 14, 2020, the March 29, 2019 and 
January 14, 2020 submittals, respectively, were determined complete by 
operation of law to meet the completeness criteria in 40 CFR part 51, 
appendix V, which must be met before formal EPA review. On November 17, 
2020, the EPA determined that the July 22, 2020 submittal met the 
completeness criteria in 40 CFR part 51, appendix V.
    The proposed SIP revisions will apply to all areas and sources in 
Arizona for which the ADEQ has permitting jurisdiction. The ADEQ has 
permitting jurisdiction for the following stationary source categories 
in all areas of Arizona: Smelting of metal ores, coal-fired electric 
generating stations, petroleum refineries, Portland cement plants, and 
portable sources. The ADEQ also has permitting jurisdiction for major 
and minor sources in the following counties: Apache, Cochise, Coconino, 
Gila, Graham, Greenlee, La Paz, Mohave, Navajo, Santa Cruz, Yavapai, 
and Yuma. Finally, ADEQ has permitting jurisdiction over major sources 
in Pinal County (currently delegated to Pinal County) and any source in 
Maricopa, Pima, or Pinal County for which the ADEQ asserts 
jurisdiction.

B. Are there other versions of the rules in the Arizona SIP?

    Table 2 lists the existing rules in the Arizona SIP that would be 
superseded or removed from the Arizona SIP as part of our proposed 
action. If the EPA were to take final action as proposed herein, these 
rules generally would be replaced in the SIP by the submitted set of 
rules listed in Table 1 of this document.

                                   Table 2--Rules To Be Superseded or Removed
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                Rule                           Title            EPA approval date     Federal Register citation
----------------------------------------------------------------------------------------------------------------
R18-2-101...........................  Definitions...........  May 4, 2018..........  83 FR 19631
R18-2-301...........................  Definitions...........  November 2, 2015.....  80 FR 67319
R18-2-302...........................  Applicability;          November 2, 2015.....  80 FR 67319
                                       Registration; Classes
                                       of Permits.
R18-2-302.01........................  Source Registration     November 2, 2015.....  80 FR 67319
                                       Requirements.
R18-2-304...........................  Permit Application      November 2, 2015.....  80 FR 67319
                                       Processing Procedures.
R18-2-306...........................  Permit Contents.......  November 2, 2015.....  80 FR 67319
R18-2-306.01........................  Permits Containing      November 2, 2015.....  80 FR 67319
                                       Voluntarily Accepted
                                       Emission Limitations
                                       and Standards.
R18-2-319...........................  Minor Permit Revisions  November 2, 2015.....  80 FR 67319
R18-2-320...........................  Significant Permit      November 2, 2015.....  80 FR 67319
                                       Revisions.
R18-2-334...........................  Minor New Source        November 2, 2015.....  80 FR 67319
                                       Review.
R18-2-406...........................  Permit Requirements     May 4, 2018..........  83 FR 19631
                                       for Sources Located
                                       in Attainment and
                                       Unclassifiable Areas.

[[Page 83870]]

 
R9-3-217, paragraph A...............  Attainment Areas;       April 23, 1982.......  47 FR 17483
                                       Classification and
                                       Standards.
----------------------------------------------------------------------------------------------------------------

C. What is the purpose of the submittals?

    On March 29, 2019, the ADEQ submitted a SIP submittal intended to 
resolve a conditional approval relating to the permitting of fine 
particular matter (PM2.5) precursors in PM2.5 
nonattainment areas. The ADEQ supplemented the submittal on January 14, 
2020 (the March 29, 2019 submittal and January 14, 2020 supplement are 
collectively referred to hereinafter as the ``Ammonia PM2.5 
NSR submittal''). The January 14, 2020 supplement also included other 
minor and technical rule revisions to the ADEQ's NSR program. On July 
22, 2020, the ADEQ submitted a SIP revision to address outstanding 
deficiencies in its NSR program, pertaining primarily to the ADEQ's 
minor NSR program, that were identified by the EPA in a final rule 
action in 2015 (referred to hereinafter as the ``2020 Minor NSR 
submittal''). In the 2020 Minor NSR submittal, the ADEQ also requested 
that the EPA remove the visibility FIPs at 40 CFR 52.27 and 52.28 as 
applied to major sources subject to the ADEQ's permitting jurisdiction, 
as its SIP-approved NSR program requirements also satisfy the CAA 
visibility requirements in 40 CFR 51.307.
    The EPA's technical support document (TSD) has more information 
about the content of these submittals (collectively referred to 
hereinafter as the ``2019-20 NSR submittals'').

II. The EPA's Evaluation

A. How is the EPA evaluating the submittals?

    The EPA has reviewed the rules and other materials submitted for 
SIP approval by the ADEQ that are the subject of this action for 
compliance with the CAA's general requirements for SIPs in CAA section 
110(a)(2), including 110(a)(2)(A) and 110(a)(2)(E)(i); \4\ the EPA's 
regulations for stationary source permitting programs in 40 CFR part 
51, subpart I; and the CAA requirements for SIP revisions in CAA 
section 110(l) and 193.
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    \4\ CAA section 110(a)(2)(A) requires that regulations submitted 
to the EPA for SIP approval be clear and legally enforceable, and 
CAA section 110(a)(2)(E)(i) requires that states have adequate 
personnel, funding, and authority under state law to carry out their 
proposed SIP revisions.
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    With respect to procedures, CAA sections 110(a)(2) and 110(l) 
require that revisions to a SIP be adopted by the state after 
reasonable notice and public hearing. The EPA has promulgated specific 
procedural requirements for SIP revisions in 40 CFR part 51, subpart F. 
These requirements include publication of notices, by prominent 
advertisement in the relevant geographic area, a public comment period 
of at least 30 days, and an opportunity for a public hearing.
    With respect to substantive requirements, we have reviewed the 
submittals that are the subject of our current action in accordance 
with the CAA and applicable regulatory requirements, focusing primarily 
on those that apply to minor NSR programs under 110(a)(2)(C) of the 
Act, Prevention of Significant Deterioration (PSD) permit programs 
under part C of title I of the Act, and Nonattainment NSR (NNSR) permit 
programs under part D of title I of the Act. The 2019-20 NSR submittals 
are primarily intended to correct the remaining deficiencies in the 
ADEQ's NSR program that we previously identified in final rule actions, 
as discussed below, and therefore we reviewed them both to determine 
whether those corrections had been made and to more generally ensure 
that the submitted rule revisions comply with the CAA and applicable 
regulatory requirements. In addition, we reviewed the ADEQ's NSR 
regulations to determine whether they meet the CAA visibility 
requirements in 40 CFR 51.307 for sources subject to PSD and NNSR 
review.
    As background, on November 2, 2015 (80 FR 67319), the EPA published 
a final limited approval and limited disapproval of a 2012 SIP revision 
submittal to the ADEQ portion of the Arizona SIP (referred to 
hereinafter as the EPA's ``2015 NSR action'').\5\ Our 2015 NSR action 
updated the ADEQ's SIP-approved NSR permitting program, but identified 
deficiencies that needed to be corrected for the EPA to grant full 
approval of the ADEQ's NSR program. Thus, our 2015 NSR action triggered 
an obligation for the EPA to promulgate a Federal Implementation Plan 
(FIP) to address the deficiencies that were the basis for our limited 
disapproval action unless the State of Arizona corrected the 
deficiencies, and the EPA approved the related plan revisions, within 
two years of that final action. In addition, to avoid sanctions under 
section 179 of the Act, the ADEQ had 18 months from December 2, 2015, 
the effective date of our 2015 NSR action, to correct those 
deficiencies related to part D of title I of the Act.
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    \5\ We also finalized other actions, which included a partial 
disapproval related to the fine particulate matter 
(PM2.5) significant monitoring concentration, and limited 
approvals, without corresponding limited disapprovals, related to 
section 189(e) of the Act.
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    On June 22, 2016 (81 FR 40525), the EPA also published a separate 
but related final limited disapproval action for the ADEQ's NNSR 
program, as the ADEQ's program did not fully address PM2.5 
precursors as required by section 189(e) of the Act (referred to 
hereinafter as the EPA's ``2016 PM2.5 precursor action''). 
This action triggered an obligation for the EPA to promulgate a FIP to 
address this deficiency unless the State of Arizona corrected the 
deficiency, and the EPA approved the related plan revisions, within two 
years of the final action. In addition, to avoid sanctions under 
section 179 of the Act, the ADEQ had 18 months from the July 22, 2016 
effective date of our 2016 PM2.5 precursor action to correct 
the deficiency as it related to part D of title I of the Act.
    On May 4, 2018 (83 FR 19631), the EPA published a final rule 
approving revisions to the ADEQ's NSR program, primarily related to the 
PSD and NNSR programs (referred to hereinafter as the ``2018 Major NSR 
action''). The 2018 Major NSR action corrected a substantial portion of 
the deficiencies identified in our 2015 NSR action and our 2016 
PM2.5 precursor action. The 2018 Major NSR action also 
included a conditional approval of the ADEQ's NNSR program related to 
one specific component of the deficiency identified in our 2016 
PM2.5 precursor action, discussed in greater detail in 
Section II.B.5 of this preamble. We note that concurrent with our 
proposed conditional approval action in 2018, we made an interim final 
determination that the State of Arizona had satisfied the requirements 
of part D of the CAA permitting program for areas under the 
jurisdiction of ADEQ with respect to

[[Page 83871]]

PM2.5 precursors under section 189(e).\6\ The effect of our 
interim final determination was that the imposition of sanctions that 
had been triggered was deferred. Following the 2018 Major NSR action, 
several outstanding deficiencies in the ADEQ's NSR program remained.
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    \6\ See 83 FR 1195 (January 10, 2018) and 83 FR 1212 (January 
10, 2018).
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    The submittals that are the subject of this proposed action are 
intended to correct the remaining deficiencies identified in our 2015 
NSR action and the deficiency that formed the basis for our conditional 
approval in our 2018 Major NSR action, so that the ADEQ's NSR program 
would be fully approved. In addition, in the 2020 Minor NSR submittal, 
the ADEQ requested that we remove the visibility FIPs at 40 CFR 52.27 
and 40 CFR 52.28, which would result from our determining that the 
ADEQ's NSR regulations meet the CAA visibility requirements in 40 CFR 
51.307 for sources subject to PSD and NNSR review under the ADEQ's 
permitting jurisdiction. Our analysis focuses on these issues; however, 
we also reviewed the submitted rules and rule revisions to ensure that 
they otherwise adhere to the relevant CAA requirements.
    For reference, the docket for the present action includes the EPA's 
TSDs for the 2015 NSR action and the 2018 Major NSR action, a June 22, 
2015 EPA memorandum, and the notice of proposed rulemaking for our 2016 
PM2.5 precursor action. The TSD for our 2015 NSR action, 
which was prepared in support of the EPA's proposal that preceded our 
final 2015 NSR action, contains a detailed discussion of the NSR 
program, its requirements, and the deficiencies we identified in the 
ADEQ's 2012 NSR SIP submittal. We note that there were several proposed 
deficiencies discussed in the 2015 TSD that we subsequently determined, 
in our final action, did not serve as bases for our limited 
disapproval. The June 22, 2015 EPA memorandum provides the list of 
deficiencies from our 2015 NSR action that formed the basis for our 
final limited disapproval of the ADEQ's 2012 NSR SIP submittal, many of 
which were addressed in our 2018 Major NSR action. Our 2016 
PM2.5 precursor action did not include a separate TSD; our 
notice of proposed rulemaking from May 2, 2016 (81 FR 26186) provides 
our detailed analysis supporting that limited disapproval action.

B. Do the submittals meet the evaluation criteria for NSR programs?

    Our 2015 NSR action, including our proposed action on March 18, 
2015 (80 FR 14044), provides a detailed discussion of the approval 
criteria for the NSR program and how the ADEQ's NSR rules that we 
reviewed in that action generally meet the approval criteria despite 
certain deficiencies that required correction in order for the EPA to 
fully approve the ADEQ's NSR program. In this action, we are focusing 
our review on the revisions that the ADEQ made to correct the remaining 
deficiencies we identified in our 2015 NSR action and the deficiency 
that formed the basis for our conditional approval in our 2018 Major 
NSR action. We also reviewed other revisions the ADEQ made in the 2019-
20 NSR submittals to ensure that the revised language is consistent 
with applicable requirements of the Act and the EPA regulations. In 
addition, we reviewed the ADEQ's NSR program regulations to determine 
whether they satisfied the CAA visibility review requirements in 40 CFR 
51.307 for sources subject to PSD or NNSR review under the ADEQ's 
permitting jurisdiction.
    We are proposing approval of the 2019-20 NSR submittals because 
they would correct the remaining deficiencies in the ADEQ's NSR program 
that we identified in our 2015 NSR action and that formed the basis for 
our conditional approval in our 2018 Major NSR action, and because they 
are otherwise consistent with the requirements for NSR programs and the 
Act. Our detailed analysis of the ADEQ's 2019-20 NSR submittals is 
provided in the TSD for this action. Below we briefly discuss the 
remaining previously identified deficiencies that this action, if 
finalized, would correct.
1. Deficiencies Corrected Related to Required Legally Enforceable 
Procedures
    The ADEQ has corrected deficiencies related to the required legally 
enforceable procedures for minor NSR permitting programs in 40 CFR 
51.160. Most of the corrections were rule revisions and are described 
below. Additionally, the ADEQ needed to provide a basis for the 
exclusion of certain stationary sources from its NSR program. Those 
demonstrations are also described further below.
    In our 2015 NSR action, the EPA found that, in some instances, the 
ADEQ's 2012 NSR submittal did not ensure that a source would not 
interfere with attainment or maintenance of the National Ambient Air 
Quality Standards (NAAQS) in neighboring areas outside the ADEQ's 
permitting jurisdiction consistent with 40 CFR 51.160(a) and (b). We 
find that the ADEQ has corrected this issue by revising the definition 
for ``attainment area'' and by revising the ADEQ rules R18-2-302.01, 
R18-2-334, and R18-2-406 to use terms that reference the NAAQS instead 
of state standards and clearly apply the NAAQS to neighboring areas. 
See R18-2-101(19), R18-2-302.01(C), R18-2-334(C)(2) and (F), and R18-2-
406(A)(5). The revisions to R18-2-101(19) and R18-2-406(A)(5) were 
approved into the Arizona SIP in our 2018 Major NSR action. The ADEQ 
also corrected an issue under 40 CFR 51.160(a) and (b) in R18-2-302.01 
by adding a reference to ``or maintenance'' of a standard, instead of 
just ``attainment of a standard'' at R18-2-302.01(C)(4).
    In our 2015 NSR action, the EPA found that for sources subject to 
the ADEQ's registration program at R18-2-302.01, the 2012 NSR submittal 
did not demonstrate that the ADEQ's NSR program met the requirement to 
ensure that sources subject to NSR review comply with the applicable 
portions of the control strategy, as required by 40 CFR 51.160(b)(1). 
The ADEQ has corrected this issue by revising R18-2-302.01(E) 
accordingly.
    As discussed in our 2015 NSR action, the ADEQ's registration 
program at R18-2-302.01 did not previously contain enforceable 
procedures for the owner or operator to submit the necessary 
information for the ADEQ to determine whether a source will violate the 
applicable control strategy or interfere with attainment or maintenance 
of the NAAQS as required by 40 CFR 51.160(c). The ADEQ corrected this 
issue by revising R18-2-302.01(A)(3) to remove a reference to R18-2-
327(C), a rule not in the SIP, and to instead use the term ``maximum 
capacity to emit with elective limits,'' which is a newly defined term 
that is used in conjunction with another newly defined term ``maximum 
capacity to emit.'' See R18-2-301(12) and (13). The term that was 
previously used, ``uncontrolled potential to emit,'' is no longer 
defined or used in the ADEQ's NSR program. We find these revisions and 
the new definitions for ``maximum capacity to emit'' and ``maximum 
capacity to emit with elective limits'' acceptable.
    Previously, the ADEQ's program did not meet the requirement that 
the applicant submit information related to the nature and amounts of 
emissions, for certain kinds of emissions units, as required by 40 CFR 
51.160(c)(1). For Class I and Class II permit applications, R18-2-304 
previously allowed sources to avoid providing emissions information for 
``insignificant activities,'' as defined in R18-2-101(68). The ADEQ 
corrected this issue by revising R18-2-304 to specify that emissions 
information from

[[Page 83872]]

insignificant activities must be provided to the extent necessary to 
determine applicability of the minor and major NSR programs (R18-2-334 
and Article 4 of ADEQ's rules, respectively). See R18-2-304(F)(8).
    Previously, for sources subject to the ADEQ's registration program 
at R18-2-302.01, the ADEQ's program did not meet the requirement in 40 
CFR 51.160(d) that its procedures provide that approval of construction 
or modification will not affect the responsibility of the owner or 
operator to comply with applicable portions of the control strategy. 
The ADEQ corrected this issue by adding this requirement for sources 
subject to R18-2-302.01, at R18-2-302.01(I).
    The EPA found in our 2015 NSR action that the ADEQ's registration 
program at R18-2-302.01 did not meet the requirement to use appendix W 
to 40 CFR part 51 for air quality modeling as required by 40 CFR 
51.160(f)(1). The ADEQ corrected this issue by revising R18-302.01(C) 
to reference a ``screening model,'' a newly defined term in revised 
R18-2-301 that requires the use of appendix W.
    In our 2015 NSR action, we found that the ADEQ's program had 
several deficiencies related to 40 CFR 51.160(e) because the 2012 NSR 
SIP submittal did not provide an adequate basis for certain sources 
that are excluded from the ADEQ's minor NSR permitting program. 40 CFR 
51.160(e) requires the ADEQ to provide a basis for the types and sizes 
of facilities, buildings, structures, or installations that will be 
subject to review under 40 CFR 51.160. That is, 40 CFR 51.160(e) allows 
state minor NSR programs to exclude some new minor sources and minor 
modifications to the extent they are inconsequential to attainment or 
maintenance of the NAAQS. We are now proposing approval of the ADEQ's 
NSR program under 40 CFR 51.160(e). The demonstrations provided by the 
ADEQ address: The ADEQ's NSR permitting exemption thresholds, as they 
apply in nonattainment areas; the ADEQ's PM2.5 NSR 
permitting threshold in attainment and nonattainment areas; the 
exemption of certain small fuel burning equipment; and the exemption of 
agricultural equipment used in normal farm operations.
    With respect to the minor NSR permitting thresholds, the ADEQ 
looked at the 2014 National Emissions Inventory for sources in Arizona 
to determine the percentage of emissions and stationary sources covered 
by the ADEQ's minor NSR program.\7\ The results show the percentage of 
stationary sources and emissions expected to be covered by the ADEQ's 
NSR program as compared to the entire state, areas of the state subject 
to the ADEQ minor NSR jurisdiction (i.e., all counties except Maricopa, 
Pima, and Pinal), and the four counties subject to state minor NSR 
jurisdiction that include nonattainment areas (Cochise, Gila, Santa 
Cruz, and Yavapai). This updated analysis, the results of which are 
included in our TSD, shows that the ADEQ's minor NSR program may cover 
a significantly higher percentage of stationary source emissions than 
originally determined, including in nonattainment areas.\8\ The ADEQ's 
updated analysis follows the same approach that the EPA used in 
developing the minor NSR program for Indian country, which we find 
acceptable. Additionally, the ADEQ's 2020 Minor NSR submittal contains 
a discussion of the types of emission sources that largely contribute 
to nonattainment in the nonattainment areas for which the ADEQ has 
minor NSR permitting jurisdiction. This discussion shows that minor 
sources are not currently significant contributors to the nonattainment 
issues in these areas.
---------------------------------------------------------------------------

    \7\ The 2012 NSR SIP submittal used data from only Maricopa 
County. The ADEQ is not the permitting authority for stationary 
sources in Maricopa County, which has lower permitting thresholds. 
The ADEQ explains that Maricopa County is a large urban area that 
may have many small sources that can contribute to nonattainment 
areas, but the nonattainment areas for which the ADEQ has minor NSR 
permitting jurisdiction are significantly different and more rural.
    \8\ The ADEQ's 2012 analysis showed that the ADEQ expected to 
cover, approximately, between 35% to 80% of emissions through its 
minor and major NSR programs. See our TSD for the 2015 NSR action, 
25, Table 5. The updated analysis in Table 3 of the TSD for this 
proposed action shows that the ADEQ is expected to cover between 69% 
to 100% of emissions through its minor and major NSR programs.
---------------------------------------------------------------------------

    While PM2.5 emissions data were not available for the 
original source distribution analysis in the 2012 NSR SIP submittal, 
the updated analysis shows that, based on the minor NSR threshold for 
PM2.5, the ADEQ's NSR program is expected to cover a high 
percentage of emissions in both attainment and nonattainment areas 
(greater than 95% in nonattainment areas). We find that the ADEQ's 
minor NSR threshold for PM2.5 provides adequate assurance 
that the sources exempted from regulation under the minor NSR program 
by the threshold would be inconsequential to attainment and maintenance 
of the NAAQS.
    In our 2015 NSR action, we found that the ADEQ needed to provide an 
interpretation of the exemption for small fuel burning equipment, rated 
less than one million British thermal units per hour (MMBtu/hr), in 
state law at Arizona Revised Statutes (ARS) section 49-426(B), and how 
it does, or does not, apply in the context of its major and minor NSR 
programs, and, to the extent such equipment is not subject to NSR 
review, the ADEQ's basis for determining that equipment exempted under 
this provision does not need to be reviewed as part of the ADEQ's minor 
NSR program under 40 CFR 51.160(e). The 2020 Minor NSR submittal 
explains that only those stationary sources that consist solely of 
equipment with a cumulative heat input rate of less than 1 MMBtu/hr are 
eligible for the exemption in ARS section 49-426(B). Because the 
exemption is only available to those stationary sources that consist 
solely of fuel burning equipment with a cumulative rating of 1 MMBtu/
hr, such sources will already be below the ADEQ's permitting exemption 
thresholds. Thus, we find this exemption and explanation acceptable.
    The 2020 Minor NSR submittal contains a detailed discussion 
describing the ADEQ's reasoning and analysis for the exemption for 
agricultural equipment used in normal farm operations in ADEQ rule R18-
2-302. See 2020 Minor NSR submittal, 9-13, 24-25. The analysis is 
summarized here. The State of Arizona exempts ``agricultural equipment 
used in normal farm operations'' from the general requirement to obtain 
a permit. See ARS 49-426(A). The ADEQ implements this exemption in its 
permitting program by exempting ``agricultural equipment used in normal 
farm operations'' from the requirement to obtain a registration or 
permit at R18-2-302(C). The exemption does not apply if the source is a 
``major source'' or if ``operation without a permit would result in a 
violation of the Act.'' Additionally, agricultural equipment used in 
normal farm operations does not include equipment classified as a 
source that requires a permit under title V of the Act, or that is 
subject to a standard under 40 CFR parts 60, 61, or 63.
    In our 2015 NSR action, we stated that the ADEQ needed to identify 
whether ``agricultural equipment used in normal farm operations'' could 
potentially be expected to occur at a stationary source subject to 
title V of the Act, 40 CFR parts 60, 61, or 63, or major NSR, and, if 
so, whether such equipment is subject to NSR review at such sources. 
The ADEQ has clarified that the exemption at R18-2-302(C) represents 
the ADEQ's interpretation of the agricultural exemption in ARS section 
49-426(A)

[[Page 83873]]

and stated that the ``rule has been recognized as valid by the Arizona 
Attorney General in its opinion supporting the state's title V program 
in 1993.'' \9\ The EPA deferred to this opinion in approving ADEQ's 
title V program in 1996. The ADEQ also clarified that the ADEQ 
interprets its permitting requirements such that its permitting 
determinations (including for the registration program) are made on a 
source-wide basis. For an exemption to apply, all the pollutant-
emitting activities within the same stationary source must qualify for 
the exemption. Therefore, if equipment used in normal farm operations 
is located at the same stationary source as non-exempt equipment that 
requires a permit, such as at a major source, a title V source, or a 
source subject to a standard under 40 CFR part 60, 61, or 63, then 
permit requirements, and potentially NSR, extend to the entire source, 
including the equipment used in the farm operations. This also means 
that the exemption is potentially available only to minor sources.
---------------------------------------------------------------------------

    \9\ Attorney General's Opinion at 2 (November 15, 1993) 
(Appendix D of the 2020 Minor NSR submittal).
---------------------------------------------------------------------------

    While the term ``normal farm operations'' is not specifically 
defined by statute or rule, the ADEQ finds the State's Agricultural 
Best Management Practices (Ag BMP) program for PM10 
nonattainment areas provides guidance on the State's interpretation for 
the types of activities that constitute normal farm operations, as 
described under the Ag BMP statute at ARS section 49-457(P)(1). The 
activities include: Tillage, planting, and harvesting; areas of a 
commercial farm that are not normally in crop production (i.e., 
fallow); areas of a commercial farm that are normally in crop 
production; significant agricultural earthmoving activities; traffic 
over unpaved access connections or unpaved roads or feed lanes; animal 
waste handling and transporting; arenas, corrals, and pens; and canals. 
The ADEQ also interprets the normal farm operations exemption to apply 
to crop and feed processing equipment that produces only fugitive 
emissions. We consider all the identified activities to be sources of 
fugitive emissions.
    The ADEQ's current SIP-approved NSR program already exempts 
fugitive emissions in determining whether a stationary source is 
subject to minor NSR permitting requirements. See R18-2-302(F). While 
this exemption does not apply to stationary sources that belong to 
certain source categories, referred to as ``section 302(j) category'' 
sources, normal farm operations are not section 302(j) category 
sources. See R18-2-101(129). This fugitive emissions exemption for 
determining minor NSR applicability reflects the same approach that the 
EPA took for its minor NSR program developed for Indian country. See 40 
CFR 49.151 through 49.161, including the definition for ``minor 
source'' and ``modification'' at 40 CFR 49.152. In the ADEQ's 
experience, the overwhelming majority of normal farm operations would 
be excluded from permitting on this basis, even if the normal farm 
operations exemption were not available. Farm emissions tend to consist 
almost exclusively of fugitive dust generated by the disturbance of 
soils.
    The ADEQ also recognizes that it is possible for equipment used in 
normal farm operations to be part of a stationary source that produces 
stack emissions greater than the permitting exemption threshold. In 
most cases, the ADEQ believes that such a stationary source would not 
qualify for the exemption. R18-2-302(C) provides that equipment used in 
normal farm operations ``does not include equipment classified as a 
source that requires a permit under title V of the Act, or that is 
subject to'' an New Source Performance Standard (NSPS) or National 
Emission Standards for Hazardous Air Pollutants (NESHAP). In addition, 
permit applicability is determined on a stationary-source-wide basis. 
Thus, if a stationary source that engaged in normal farm operations 
qualified as a title V source or included equipment subject to an NSPS 
or NESHAP, the entire source would require a permit and potentially be 
subject to minor NSR if its emissions were above the NSR permitting 
exemption thresholds. In the ADEQ's experience, most permitted sources 
include one or more pieces of equipment subject to an NSPS. It is 
therefore likely that if equipment used in normal farm operations were 
collocated with equipment with stack emissions exceeding the permitting 
exemption thresholds, at least some of that equipment would be subject 
to an NSPS, and the normal farm operations exemption would not apply. 
Additionally, a source with equipment subject to a NESHAP or a source 
that qualifies as a title V source would not be exempted.
    Finally, the ADEQ stated that under R18-2-302(C), equipment used in 
normal farm operations is not exempt if ``operation [of the equipment] 
without a permit would result in a violation of the Act,'' which 
provides a final safeguard. In the few remaining potential situations 
where equipment used in normal farm operations is located at a 
stationary source with stack emissions above the permitting exemption 
threshold that is not subject to 40 CFR parts 60, 61, 63 or title V, 
the ADEQ will invoke this provision to ensure that any such source does 
not endanger attainment or maintenance of the NAAQS or enforcement of 
the control strategy.
    In sum, the ADEQ has demonstrated that its exemption for 
agricultural equipment used in normal farm operations is extremely 
limited in scope, and the potential sources exempted from permitting 
would be inconsequential to attainment and maintenance of the NAAQS. 
This determination is based on the ADEQ's interpretation of the narrow 
manner in which the exemption applies, the limited types of operations 
that are considered to be ``normal farm operations,'' and the ADEQ's 
retention of authority to address any potentially exempt sources that 
may endanger attainment or maintenance of the NAAQS or enforcement of 
the control strategy. We agree that the vast majority of these 
operations are likely already exempted from the ADEQ's SIP-approved 
minor NSR program under the general exemption for excluding fugitive 
emissions in permitting applicability determinations. We find the 
ADEQ's basis and explanation for the exemption from minor NSR review 
for agricultural equipment used in normal farm operations to be 
acceptable.
2. Deficiencies Corrected Related to Public Availability of Information
    In our 2015 NSR action, the EPA identified several deficiencies 
with the ADEQ's NSR program concerning the requirements related to 
public availability of information in 40 CFR 51.161. First, the ADEQ's 
program did not ensure that all minor sources subject to NSR review 
under the ADEQ's NSR program, as the ADEQ defined it pursuant to 40 CFR 
51.160(e), are subject to public notice and comment consistent with 40 
CFR 51.161(a). The ADEQ corrected this deficiency by revising R18-2-334 
to remove the previous public notice exemption for certain permit 
applications. Additionally, the 2020 Minor NSR submittal clarifies that 
the use of the term ``construction,'' as defined in R18-2-101(32), in 
R18-2-302.01 ensures that modifications to a registered source at or 
above the permitting exemption thresholds will be subject to public 
notice. Next, the ADEQ's registration program at R18-2-302.01 
previously did not contain sufficient enforceable procedures for 
sources taking ``elective

[[Page 83874]]

limits'' to limit their potential to emit in a manner that allows the 
source to avoid the public participation requirements in 40 CFR 
51.161(a), while otherwise being subject to the registration program. 
The ADEQ corrected this deficiency by adding additional specificity to 
how elective limits are set, ensuring that such limits will include the 
time period over which the limitations apply, and ensuring sufficient 
recordkeeping to demonstrate compliance. See R18-2-302.01(F).
    The ADEQ's NSR program also did not include sufficient public 
notice procedures for registrations or the proposed disapproval of an 
application consistent with 40 CFR 51.161(a). The ADEQ revised R18-2-
330 to clarify the public notice procedures for registrations and to 
require public notice for a proposed disapproval of an application. See 
R18-2-330(A). We approved the revisions to R18-2-330 in our 2018 Major 
NSR action but did not note in that action that the revisions corrected 
this deficiency.\10\
---------------------------------------------------------------------------

    \10\ A copy of the SIP-approved R18-2-330 is included in the 
docket for this action.
---------------------------------------------------------------------------

    Finally, in our 2015 NSR action, the EPA identified as a deficiency 
that the ADEQ's NSR program did not provide notice to the necessary 
parties identified in 40 CFR 51.161(d) for sources required to obtain 
registrations under R18-2-302.01. The ADEQ corrected this deficiency by 
adding this requirement at R18-2-302.01(B)(4).
3. Deficiencies Corrected Related to Administrative Procedures
    40 CFR 51.163 requires each NSR program to include the 
administrative procedures that will be followed in reviewing new and 
modified sources, as specified in 40 CFR 51.160(a). In our 2015 NSR 
action, we found that the ADEQ's 2012 NSR SIP submittal contained 
administrative procedures consistent with 40 CFR 51.163; however, not 
all the procedures referenced in the 2012 NSR SIP submittal were 
submitted for inclusion into the SIP. The ADEQ corrected this 
deficiency by submitting R18-2-317, R18-2-317.01, and R18-2-317.02. 
These rules generally identify the types of changes at Class I and II 
sources that do or do not require a permit revision and require that 
projects triggering minor or major NSR review obtain permit revisions 
in advance. We have reviewed these rules for inclusion in the ADEQ's 
SIP-approved NSR program and find them acceptable.
4. Resolution of Minor NSR Program Deficiencies
    For the reasons stated above, we propose to find that the 2019-2020 
NSR submittals correct all remaining deficiencies in the ADEQ's minor 
NSR program that were identified in our 2015 NSR action as the basis 
for our limited disapproval.
5. Resolution of PM2.5 NNSR Program Deficiency
    The only outstanding deficiency in the ADEQ's NNSR program 
identified in our earlier actions relates to the treatment of ammonia 
as a precursor to PM2.5 for the West Central Pinal and 
Nogales PM2.5 nonattainment areas. As background, in 2016, 
the EPA finalized regulatory requirements for SIPs related to 
implementing the 2012 PM2.5 NAAQS (``2012 PM2.5 
implementation rule'').\11\ The 2012 PM2.5 implementation 
rule included regulatory requirements that states must adopt in 
permitting programs in PM2.5 nonattainment areas to address 
the requirements for PM2.5 precursors for major stationary 
sources under section 189(e) of the Act. For purposes of the NNSR 
program, the EPA specified that PM2.5 precursors in 
PM2.5 nonattainment areas include NOX, VOC, 
SO2, and ammonia. See 40 CFR 51.165(a)(1)(xxxvii)(C)(2).
---------------------------------------------------------------------------

    \11\ See Fine Particulate Matter National Ambient Air Quality 
Standards: State Implementation Plan Requirements, 81 FR 58010 
(August 24, 2016).
---------------------------------------------------------------------------

    In the EPA's 2016 PM2.5 precursor action, we finalized a 
narrow, limited disapproval action for deficiencies in the ADEQ's NNSR 
program related to PM2.5 precursors in PM2.5 
nonattainment areas.\12\ For PM2.5 nonattainment areas, CAA 
section 189(e) requires that the control requirements applicable under 
plans in effect under part D of the CAA for major stationary sources of 
PM2.5 also apply to major stationary sources of 
PM2.5 precursors, except where the EPA determines that such 
sources do not contribute significantly to PM2.5 levels that 
exceed the standards in the area. In our 2016 PM2.5 
precursor action, we determined that the ADEQ's 2012 NSR SIP submittal 
did not fully satisfy the major NNSR requirements for PM2.5 
under section 189(e) of the Act for the Nogales and West Central Pinal 
PM2.5 nonattainment areas, based on our finding that the 
submittal did not include rules regulating VOCs or ammonia as 
PM2.5 precursors under the NNSR program, nor did it include 
a demonstration showing that the regulation of VOCs and ammonia was not 
necessary under section 189(e).\13\
---------------------------------------------------------------------------

    \12\ See 81 FR 40525.
    \13\ See id. Our 2016 proposed action contained a detailed 
discussion of the ADEQ's PM2.5 NSR program and this 
limited disapproval issue. See Proposed Rule, Limited Disapproval of 
Air Plan Revisions; Arizona; New Source Review; PM 2.5. 
81 FR 26185 (May 2, 2016).
---------------------------------------------------------------------------

    In our 2018 Major NSR action, we found that the ADEQ's April 28, 
2017 SIP revision submittal (``2017 Major NSR submittal''), which 
mostly pertained to NSR program updates for major sources, contained 
revisions that updated the ADEQ's NNSR program to address all the 
deficiencies with that program that were identified in our 2015 NSR 
action. We also found that the ADEQ's 2017 Major NSR submittal 
addressed the deficiencies we identified in our 2016 PM2.5 
precursor action related to PM2.5 precursors in 
PM2.5 nonattainment areas, with one exception: We found that 
the ADEQ's rule revisions did not fully meet the requirements of the 
2012 PM2.5 implementation rule as it relates to ammonia as a 
PM2.5 precursor. Specifically, while the ADEQ's NNSR program 
included ammonia as a precursor to PM2.5, at R18-2-
101(124)(a)(iv), we found that the 2017 Major NSR submittal did not 
define the threshold at which emissions increases of ammonia are 
considered ``significant'' for determining when modifications at 
existing major sources of ammonia are major modifications subject to 
NNSR, as required by 40 CFR 51.165(a)(1)(x)(F).\14\
---------------------------------------------------------------------------

    \14\ See 83 FR 19631.
---------------------------------------------------------------------------

    Accordingly, while our 2018 Major NSR action approved the rule 
revisions in the ADEQ's 2017 Major NSR submittal, our action also 
included a conditional approval with respect to ammonia as precursor to 
PM2.5 emissions in PM2.5 nonattainment areas. A 
December 6, 2017 commitment letter from the ADEQ provided adequate 
assurance that the remaining NNSR program deficiency related to ammonia 
as a PM2.5 precursor in PM2.5 nonattainment areas 
would be addressed in a timely manner, consistent with CAA section 
110(k)(4). Our 2018 Major NSR action conditionally approved the ADEQ's 
NSR program with respect to ammonia as a PM2.5 precursor 
based on this commitment. The ADEQ's Ammonia PM2.5 NSR 
submittal satisfies the requirements of our conditional approval and 
corrects this outstanding deficiency.
    Specifically, the ADEQ's Ammonia PM2.5 NSR submittal 
includes a rule revision that sets a rate of 40 tons per year as 
``significant'' in reference to the significant emission rate (SER) 
used to

[[Page 83875]]

determine those projects that constitute a major modification at major 
sources of ammonia. See R18-2-101(131)(f). A SER of 40 tpy for ammonia 
has been approved by the EPA for several other PM2.5 
nonattainment areas,\15\ and the ADEQ set this value in consultation 
with EPA Region 9. Our approval of the submitted ammonia SER will 
resolve the remaining deficiency that formed the basis for our 
conditional approval in our 2018 Major NSR action, and therefore we are 
proposing to remove the conditional approval language from 40 CFR 
52.119(a), as the condition has been met. We also note that the 
sanctions and sanctions clocks triggered by our 2016 PM2.5 
precursor action, as discussed in Section II.A of this preamble, would 
be permanently terminated on the effective date of our final approval 
of the Ammonia PM2.5 NSR submittal.\16\
---------------------------------------------------------------------------

    \15\ For example, the EPA has approved an ammonia SER of 40 tpy 
for Alleghany County, Pennsylvania (85 FR 36161, June 15, 2020); 
Knox County, Tennesse (83 FR 46880, September 17, 2018); Imperial 
County, California 84 FR 44545, (August 26, 2019); and Los Angeles--
South Coast Air Basin, CA (83 FR 61551, November 30, 2018).
    \16\ See 83 FR 19631, 19633, 19634 (May 4, 2018).
---------------------------------------------------------------------------

6. Resolution of PSD Program Deficiency
    In our 2015 NSR action, we determined that the ADEQ had adopted the 
PSD increments, or maximum allowable increases, in R18-2-218--
Limitation of Pollutants in Classified Attainment Areas, but noted that 
in other rules, the ADEQ used the terms ``increment'' or ``incremental 
ambient standard'' where it appeared the intent was to refer to the 
standards established in R18-2-218 and identified in the ADEQ's rules 
as the ``maximum allowable increases.'' The ADEQ's April 2017 NSR 
submittal included corrections to these provisions, which now 
consistently refer to these maximum allowable increases. See R18-2-
406(E), R18-2-412(G)(2)(b), R18-2-101(51). However, we noted in our 
2018 Major NSR action that the ADEQ needed to also correct this issue 
in R18-2-319(A)(3) and R18-2-320(B)(6). While the ADEQ had revised 
these rules to address this issue, these rules were not included in the 
April 2017 NSR submittal. The 2020 Minor NSR submittal contains R18-2-
319 and R18-2-320 with the necessary corrections. Thus, we find that 
this deficiency identified in our 2015 NSR action has been fully 
addressed.
7. Additional Revisions Made to the ADEQ's NSR Program
    In 2017, the EPA finalized revisions to the Guideline on Air 
Quality Models at Appendix W of 40 CFR part 51.\17\ The revisions 
became effective on May 22, 2017.\18\ The ADEQ updated its NSR program 
to reference 40 CFR part 51, appendix W as of June 30, 2017 in R18-2-
301, R18-2-334, and R18-2-406. The updated cross-reference in these 
ADEQ rules to 40 CFR part 51, appendix W incorporates the latest 
revisions to the Guideline on Air Quality Models. Our proposed approval 
of R18-2-301, R18-2-334, and R18-2-406 will ensure that the ADEQ 
portion of the Arizona SIP is updated to incorporate these new 
revisions.
---------------------------------------------------------------------------

    \17\ 82 FR 5182 (January 17, 2017).
    \18\ 82 FR 14324 (March 20, 2017).
---------------------------------------------------------------------------

    In addition to the other revisions discussed above, the ADEQ has 
made other minor revisions and updates to some of the submitted rules 
that have not yet been approved into the Arizona SIP. Two final rule 
actions completed by the ADEQ, which are included in the docket for 
this action, show the specific revisions that have been made to the 
rules in the 2019-20 NSR submittals. In the ADEQ's February 10, 2017 
final rule, see revisions to R18-2-301, R18-2-302, R18-302.01, R18-304, 
R18-2-306, R18-2-306.01, R18-2-319, R18-2-320, and R18-2-334. In the 
ADEQ's December 20, 2019 final rule, see revisions to R18-2-101, R18-2-
301, R18-2-302.01, R18-2-304, R18-2-334, and R18-2-406. We have 
reviewed each of the changes and determined that they are acceptable 
and do not create any new disapproval issues. The changes generally 
relate to correcting typographical errors, clarifying rule language, 
and moving permit application requirements from an appendix to R18-2-
304.

C. Evaluation of Rules Requested To Be Removed From the SIP

    Table 2 of this preamble identifies the rules, or portions thereof, 
that the ADEQ has requested to be removed from the Arizona SIP, and 
which we are proposing in this action to remove from the Arizona SIP. 
All but one of these rules will be replaced by the newer rules in the 
2019-20 NSR submittals that are the subject of our current action. 
Except for R9-3-217, paragraph A, the rules we are proposing to replace 
are older versions of the rules in the 2019-20 NSR submittals. The 
older versions contained deficiencies that the ADEQ needed to correct, 
or language that the ADEQ otherwise determined needed to be updated to 
enhance the ADEQ's program or to ensure that it meets new requirements. 
The removal of these older rules would not relax any requirements in 
the Arizona SIP. For the reasons stated above, we find the removal of 
these rules from the SIP to be acceptable and we propose to approve the 
ADEQ's request to remove these rules from the SIP.

D. Approval of Program for Visibility Protection in Class I Areas

    The ADEQ's 2020 Minor NSR submittal requests that the EPA remove 
the FIPs at 40 CFR 52.145(b) related to visibility protection in Class 
I areas at 40 CFR 51.307, as they pertain to major stationary sources 
for which the ADEQ has PSD or NNSR jurisdiction. The relevant 
substantive visibility FIP requirements that currently apply to such 
sources are found at 40 CFR 52.27 (PSD sources) and 40 CFR 52.28 (NNSR 
sources). These FIPs were established for sources subject to the ADEQ's 
PSD and NNSR programs because the EPA had not approved the ADEQ's 
visibility program under 40 CFR 51.307. Approval of the ADEQ's 
visibility program under 40 CFR 51.307 would mean that these FIPs are 
no longer needed to satisfy the CAA visibility program requirements at 
40 CFR 51.307 for sources subject to the ADEQ's PSD and NNSR programs. 
The evaluation in Attachment 1 to our TSD for this action includes the 
results of our review from 2017 of how the ADEQ's NSR program rules 
meet each of the required elements for CAA visibility programs in 40 
CFR 51.307. Based on our review, we have determined that the ADEQ's PSD 
and NNSR program rules satisfy the requirements of 40 CFR 51.307, and 
we are proposing to approve the ADEQ's SIP-approved NSR rules as 
meeting those requirements. In conjunction with our SIP approval of 
ADEQ's visibility program for major sources subject to review under the 
PSD and NNSR programs, we also propose to revise the applicability of 
the visibility FIPs at 40 CFR 52.27 and 40 CFR 52.28 as they pertain to 
Arizona at 40 CFR 52.145(b), as these FIPs will no longer apply to 
sources subject to review under ADEQ's PSD and NNSR programs. This 
revision will clarify the application of these FIPs in Arizona 
following our final action.
    We note that the visibility FIP at 40 CFR 52.28 would continue to 
apply to sources within Arizona subject to review under the CAA NNSR 
program that are or would be located on any Indian reservation land or 
in any other area where the EPA or an Indian tribe has demonstrated 
that a tribe has jurisdiction. Similarly, the FIP at 40 CFR 52.28 would 
also remain in place for sources in Arizona subject to review

[[Page 83876]]

under the Pima County Division of Environmental Quality's SIP-approved 
NNSR program. The EPA has previously approved the visibility review 
requirements in the Maricopa County Air Quality Department's SIP-
approved NNSR program as satisfying the requirements in 40 CFR 51.307. 
See 84 FR 13543 (April 19, 2019). We also note that for sources within 
Arizona subject to PSD review that are or would be located on any 
Indian reservation land or in any other area where the EPA or an Indian 
tribe has demonstrated that a tribe has jurisdiction, the FIP at 40 CFR 
52.27 would not apply; rather, the PSD FIP at 40 CFR 52.21 that 
otherwise applies to such sources \19\ includes requirements that fully 
address the visibility program requirements at 40 CFR 51.307.
---------------------------------------------------------------------------

    \19\ See 40 CFR 52.144(a) and (b).
---------------------------------------------------------------------------

E. Do the rules meet the evaluation criteria under Sections 
110(a)(2)(A), 110(a)(2)(E)(i), 110(l) and 193 of the Clean Air Act?

    CAA section 110(a)(2)(A) requires that regulations submitted to the 
EPA for SIP approval be clear and legally enforceable. We have 
determined that the rules listed in Table 1 of this preamble are clear 
and legally enforceable and therefore satisfy this requirement.
    CAA section 110(a)(2)(E)(i) requires SIPs to provide ``necessary 
assurances that the State (or, except where the Administrator deems 
inappropriate, the general purpose local government or governments, or 
a regional agency designated by the State or general purpose local 
governments for such purpose) will have adequate personnel, funding, 
and authority under State (and, as appropriate, local) law to carry out 
such implementation plan (and is not prohibited by any provision of 
Federal or State law from carrying out such implementation plan or 
portion thereof).'' In the EPA's recent actions on Arizona's 
Infrastructure SIP for the 2010 nitrogen dioxide (NO2) and 
2010 sulfur dioxide (SO2) NAAQS, we conducted a detailed 
evaluation of Arizona legal authorities that provide for the ADEQ's 
implementation and enforcement of CAA requirements related to that 
Infrastructure SIP, as well as information showing that the ADEQ has 
adequate funding and personnel to implement the relevant CAA SIP 
requirements, and approved that SIP submittal with respect to CAA 
section 110(a)(2)(E)(i).\20\ Accordingly, the ADEQ has provided the 
necessary assurances that the ADEQ will have adequate personnel, 
funding, and authority under State law to carry out the proposed 
revisions to the ADEQ's SIP, consistent with CAA section 
110(a)(2)(E)(i).
---------------------------------------------------------------------------

    \20\ See 83 FR 42214 (September 20, 2018); including ``Technical 
Support Document for Notice of Final Rulemaking: Evaluation of 
Arizona's Infrastructure SIP for 2010 NO2 and 2010 SO2'' 
July 30. 2018 (document ID number EPA-R09-OAR-2015-0472-0042), 24-
28.
---------------------------------------------------------------------------

    Section 110(l) states: ``Each revision to an implementation plan 
submitted by a State under this chapter shall be adopted by such State 
after reasonable notice and public hearing. The Administrator shall not 
approve a revision of a plan if the revision would interfere with any 
applicable requirement concerning attainment and reasonable further 
progress (as defined in section 7501 of this title), or any other 
applicable requirement of this chapter.'' With respect to the 
procedural requirements of CAA section 110(l), based on our review of 
the public process documentation included in the submittal, we find 
that the ADEQ has provided sufficient evidence of public notice and 
opportunity for comment and public hearings prior to submittal of this 
SIP revision and has satisfied these procedural requirements under CAA 
section 110(l). With respect to the substantive requirements of section 
110(l), we have determined that our action on the 2019-20 NSR 
submittals would, as described herein, strengthen the applicable SIP. 
This action is primarily intended to correct numerous deficiencies in 
the ADEQ's NSR program and provides other revisions to enhance and 
update the program. Accordingly, this action will not interfere with 
attainment and reasonable further progress, or any other applicable 
requirement.
    Section 193 of the Act, which was added by the Clean Air Act 
Amendments of 1990, includes a savings clause which provides, in 
pertinent part: ``No control requirement in effect, or required to be 
adopted by an order, settlement agreement, or plan in effect before 
November 15, 1990, in any area which is a nonattainment area for any 
air pollutant may be modified after November 15, 1990, in any manner 
unless the modification insures equivalent or greater emission 
reductions of such air pollutant.'' We find that the provisions 
included in 2019-20 NSR submittals would ensure equivalent or greater 
emission reductions as compared to the current SIP-approved NSR program 
in the nonattainment areas under ADEQ's jurisdiction. Further, this 
action does not modify any pre-1990 requirements applicable to 
nonattainment areas. For the reasons set forth above, our proposed 
approval of the 2019-20 NSR submittals is consistent with section 193 
of the Act.

F. Conclusion

    As discussed in detail above, we propose to find that the ADEQ has 
corrected all remaining deficiencies identified as the bases for 
limited disapproval in our 2015 NSR action and the basis for our 
conditional approval in our 2018 Major NSR action. In addition, we 
reviewed all other changes the ADEQ made to its NSR program in the 
submitted rules for consistency with CAA requirements to ensure that no 
new disapproval issues have been created. With the corrections and 
demonstrations discussed above, our prior limited disapproval in 2015 
and conditional approval in 2018 will become a full approval of the 
ADEQ's minor NSR program, PSD program, and NNSR program, and we are 
proposing full approval of the 2019-20 NSR submittals. The new and 
revised rules evaluated herein meet the applicable CAA requirements. 
Our proposed action would have the effect of updating the ADEQ's SIP-
approved NSR program and correcting previously identified deficiencies 
and recognizing that the ADEQ's NSR program requirements also satisfy 
the CAA visibility requirements in 40 CFR 51.307.

III. Public Comment and Proposed Action

    Pursuant to section 110(k)(3) of the CAA and for the reasons 
provided above, the EPA is proposing to approve the revisions to the 
ADEQ portion of the Arizona SIP that govern the issuance of permits for 
stationary sources, under section 110(a)(2)(C) of the Act and parts C 
and D of title I of the Act. Specifically, the EPA is proposing to 
approve the new and amended ADEQ regulations listed in Table 1 of this 
preamble, as a revision to the ADEQ portion of the Arizona SIP. In 
addition, the EPA is proposing to remove the existing SIP-approved 
rules listed in Table 2 of this preamble. Further, for the West Central 
Pinal and Nogales PM2.5 nonattainment areas, the sanctions 
and sanctions clock triggered by our 2016 PM2.5 precursor 
action under CAA section 179 would be permanently terminated on the 
effective date of our final approval of the Ammonia PM2.5 
NSR submittal. Finally, we are also proposing that the ADEQ's SIP-
approved program meets the visibility requirements in 40 CFR 51.307 for 
NSR programs and are proposing to remove the existing visibility FIPs 
for sources subject to review under the ADEQ's SIP-approved PSD or NNSR

[[Page 83877]]

permitting program. We are proposing this action because we find that 
the 2019-20 NSR submittals meet the applicable requirements under parts 
C and D of title I of the CAA, and that our action is consistent with 
sections 110(a)(2), 110(l) and 193 of the Act.
    We will accept comments from the public on this proposal until 
January 22, 2021. If we take final action to approve the 2019-20 NSR 
submittals, our final action will incorporate the identified rule(s) 
into the federally enforceable SIP.

IV. Incorporation by Reference

    In this rule, the 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, the EPA is proposing to incorporate by 
reference the ADEQ rules described in Table 1 of this preamble. The EPA 
has made, and will continue to make, these materials available through 
https://www.regulations.gov and at the EPA Region IX Office (please 
contact the person identified in the FOR FURTHER INFORMATION CONTACT 
section of this preamble for more information).

V. Statutory and Executive Order Reviews

    Under the CAA, the Administrator is required to approve a SIP 
submission that complies with the provisions of the Act and applicable 
federal regulations. 42 U.S.C. 7410(k); 40 CFR 52.02(a). Thus, in 
reviewing SIP submissions, the EPA's role is to approve state choices, 
provided that they meet the criteria of the Act. Accordingly, this 
proposed action merely proposes to approve state law as meeting federal 
requirements and does not impose additional requirements beyond those 
imposed by state law. For that reason, this proposed action:
     Is not a ``significant regulatory action'' subject to 
review by the Office of Management and Budget under Executive Orders 
12866 (58 FR 51735, October 4, 1993) and 13563 (76 FR 3821, January 21, 
2011);
     Is not an Executive Order 13771 (82 FR 9339, February 3, 
2017) regulatory action because SIP approvals are exempted under 
Executive Order 12866;
     Does not impose an information collection burden under the 
provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
     Is certified as not having a significant economic impact 
on a substantial number of small entities under the Regulatory 
Flexibility Act (5 U.S.C. 601 et seq.);
     Does not contain any unfunded mandate or significantly or 
uniquely affect small governments, as described in the Unfunded 
Mandates Reform Act of 1995 (Pub. L. 104-4);
     Does not have federalism implications as specified in 
Executive Order 13132 (64 FR 43255, August 10, 1999);
     Is not an economically significant regulatory action based 
on health or safety risks subject to Executive Order 13045 (62 FR 
19885, April 23, 1997);
     Is not a significant regulatory action subject to 
Executive Order 13211 (66 FR 28355, May 22, 2001);
     Is not subject to requirements of Section 12(d) of the 
National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272 
note) because application of those requirements would be inconsistent 
with the CAA; and
     Does not provide the EPA with the discretionary authority 
to address disproportionate human health or environmental effects with 
practical, appropriate, and legally permissible methods under Executive 
Order 12898 (59 FR 7629, February 16, 1994).

In addition, the SIP is not approved to apply on any Indian reservation 
land or in any other area where the EPA or an Indian tribe has 
demonstrated that a tribe has jurisdiction. In those areas of Indian 
country, the rule does not have tribal implications and will not impose 
substantial direct costs on tribal governments or preempt tribal law as 
specified by Executive Order 13175 (65 FR 67249, November 9, 2000).

List of Subjects in 40 CFR Part 52

    Environmental protection, Air pollution control, Carbon monoxide, 
Incorporation by reference, Intergovernmental relations, Nitrogen 
dioxide, Ozone, Particulate matter, Sulfur dioxide, Reporting and 
recordkeeping requirements, Volatile organic compounds.

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

    Dated: December 8, 2020.
John Busterud,
Regional Administrator, Region IX.
[FR Doc. 2020-27952 Filed 12-22-20; 8:45 am]
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