[Federal Register Volume 86, Number 103 (Tuesday, June 1, 2021)]
[Proposed Rules]
[Pages 29219-29222]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-11395]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R09-OAR-2021-0249; FRL-10022-26-Region 9]


Rescission of Clean Data Determination and Call for Attainment 
Plan Revision for the Yuma, AZ 1987 PM10 Moderate Nonattainment Area

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: The Environmental Protection Agency (EPA) is proposing to 
rescind its previously issued clean data determination for the Yuma, 
Arizona ``Moderate'' nonattainment area for the 1987 24-hour national 
ambient air quality standard (NAAQS) for particulate matter with an 
aerodynamic diameter less than or equal to a nominal 10 micrometers 
(PM10) because recent complete, quality-assured monitoring 
data show that the area has subsequently violated this NAAQS. We are 
also proposing to find that the Arizona State Implementation Plan (SIP) 
is substantially inadequate to attain or maintain the PM10 
standard and to call for Arizona to revise the SIP to address this 
inadequacy.

DATES: Any comments must arrive by July 1, 2021.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R09-
OAR-2021-0249 at http://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. For either manner of submission, 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 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. 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: John J. Kelly, Air Planning Office 
(AIR-2), EPA Region IX, (415) 947-4151, [email protected].

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

Table of Contents

I. Background
    A. The 1987 PM10 NAAQS
    B. Designation and Classification of the Yuma PM10 
Nonattainment Area
    C. The Clean Data Policy and the 2006 Clean Data Determination
II. Current Monitoring Data
III. Proposed Action and Request for Public Comment
IV. Statutory and Executive Order Reviews

I. Background

A. The 1987 PM10 NAAQS

    The EPA sets NAAQS for certain ambient air pollutants at levels 
required to protect human health and the environment. The primary NAAQS 
represent ambient air quality standards the attainment and maintenance 
of which the EPA has determined are requisite to protect public health, 
including an adequate margin of safety. The secondary NAAQS represent 
ambient air quality standards the attainment and maintenance of which 
the EPA has determined are requisite to protect public welfare from any 
known or anticipated adverse effects associated with the presence of 
such air pollutant in the ambient air. PM10 is one of these 
ambient air pollutants for which the EPA has established NAAQS. On July 
1, 1987, the EPA promulgated two primary standards for PM10: 
A 24-hour standard of 150 micrograms per cubic meter ([mu]g/m\3\) and 
an annual PM10 standard of 50 [mu]g/m\3\. The EPA also 
promulgated secondary PM10 standards that were identical to 
the primary standards.\1\ Effective December 18, 2006, the EPA revoked 
the annual PM10 NAAQS but retained the 24-hour 
PM10 NAAQS.\2\ Because they are identical, we refer to the 
primary and secondary 24-hour standards using the single term, NAAQS.
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    \1\ 52 FR 24634 (July 1, 1987).
    \2\ 71 FR 61144 (October 17, 2006).
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    The 24-hour PM10 NAAQS is attained when the expected 
number of exceedances, averaged over a three-year period, is less than 
or equal to one. The expected number of exceedances averaged over a 
three-year period at any given monitor is known as the PM10 
design value for that site. The PM10 design value for the 
nonattainment area is the highest design value from a monitor within 
that area. The methodologies for calculating expected exceedances for 
the 24-hour PM10 NAAQS are found in 40 CFR part 50, appendix 
K, Section 2.1(a).

B. Designation and Classification of the Yuma PM10 Nonattainment Area

    Upon enactment of the 1990 Amendments to the Clean Air Act (CAA or 
``Act''), the Act itself designated specific areas as nonattainment by 
operation of law, and classified these areas as Moderate.\3\ These 
areas included all former Group I PM10 planning areas 
identified in Federal Register documents published on August 7, 
1987,\4\ and October 31, 1990,\5\ and any other areas violating the 
1987 PM10 NAAQS prior to January 1, 1989. The EPA published 
a Federal Register document announcing the areas designated 
nonattainment for PM10 upon enactment of the 1990 CAA 
Amendments, known as ``initial'' PM10 nonattainment areas, 
on March 15, 1991.\6\ The EPA published a subsequent Federal Register 
document correcting some of these areas on August 8, 1991.\7\ These 
nonattainment designations and Moderate area classifications were 
codified in 40 CFR part 81 on November 6, 1991.\8\ The EPA designated 
as ``unclassifiable'' all other areas in the Nation not designated 
nonattainment

[[Page 29220]]

upon enactment of the 1990 CAA Amendments.\9\
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    \3\ 42 U.S.C. 7407(d)(4)(B), 7513(a).
    \4\ 52 FR 29383.
    \5\ 55 FR 45799.
    \6\ 56 FR 11101.
    \7\ 56 FR 37654.
    \8\ 56 FR 56694.
    \9\ See CAA section 107(d)(4)(B)(iii).
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    The Yuma PM10 nonattainment area (``Yuma NAA'') was one 
of the areas specified by Congress and designated by the 1990 CAA 
Amendments. Specifically, the Yuma NAA was designated nonattainment by 
section 107(d)(4)(B)(i) of the Act and classified as Moderate because 
it had been previously categorized as a Group I area.\10\ The EPA 
announced the Yuma NAA designation, as required by section 107(d)(2) of 
the Act, on March 15, 1991.\11\ In accordance with CAA section 
189(a)(2), Arizona was required to submit a SIP revision meeting 
applicable nonattainment plan requirements by November 15, 1991, 
demonstrating attainment of the 1987 p.m.10 NAAQS in the 
Yuma NAA by December 31, 1994.\12\
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    \10\ 52 FR 29383 (August 7, 1987).
    \11\ 56 FR 11101.
    \12\ Arizona submitted a Moderate area plan for the Yuma NAA on 
November 14, 1991. The EPA found this plan to be incomplete on May 
14, 1992. Arizona submitted a revised plan for the Yuma NAA on July 
12, 1994, but withdrew this plan in 2006, following the EPA's 
issuance of a clean data determination for the Yuma NAA.
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C. The Clean Data Policy and the 2006 Clean Data Determination

    In nonattainment areas where monitored data demonstrate that the 
NAAQS has been attained, the EPA interprets certain requirements of the 
Act as no longer being applicable for so long as air quality continues 
to meet the NAAQS in the area. This interpretation is known as the 
``clean data policy,'' and EPA findings issued under this policy are 
known as ``clean data determinations.'' On March 14, 2006, the EPA 
issued a clean data determination for the Yuma NAA for the 1987 24-hour 
PM10 NAAQS, based on complete, quality-assured and certified 
PM10 monitoring data for 2002-2004.\13\ Because the data 
from 2002-2004 were complete and showed no exceedances of the relevant 
NAAQS, and because preliminary data for 2005 also indicated no such 
exceedances, the EPA concluded that the Yuma NAA was in attainment for 
the 1987 24-hour PM10 NAAQS.\14\ Based on this finding, the 
EPA determined that certain nonattainment plan requirements in the Yuma 
NAA were not applicable for so long as the Yuma NAA continued to 
monitor attainment of the 1987 24-hour PM10 and annual 
NAAQS.\15\
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    \13\ 71 FR 13021 (March 14, 2006).
    \14\ The clean data determination also applied to the annual 
PM10 NAAQS, but that NAAQS was revoked later that year. 
See 71 FR 61144 (October 17, 2006).
    \15\ In the same Federal Register document, the EPA also 
determined pursuant to CAA sections 179(c)(1) and 188(b)(2) that the 
Yuma NAA had attained the NAAQS by the Moderate area attainment date 
of December 31, 1994. Because that determination was tied to that 
specific attainment date, it would not be affected by the rescission 
of the clean data determination proposed in this action.
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II. Current Monitoring Data

    In accordance with 40 CFR part 50, appendices J and K, a finding of 
whether an area has attained or is currently attaining the 1987 24-hour 
PM10 NAAQS must generally be based upon certified, complete, 
quality-assured data gathered at monitoring sites in the nonattainment 
area and entered into the EPA's Air Quality System (AQS) database. For 
the 1987 24-hour PM10 NAAQS, appendix K provides that all 
data produced by state and local air monitoring sites (SLAMS) and other 
sites submitted to the EPA in accordance with the part 58 requirements 
be used for evaluating attainment.\16\
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    \16\ 40 CFR part 50, appendix K, section 2.3(a).
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    In order to assess whether an area is currently attaining the 
NAAQS, the PM10 ambient air quality monitoring data 
collected by the state within the area for the three-year period must 
meet data completeness criteria, or otherwise unambiguously establish 
nonattainment according to 40 CFR part 50, appendix K, section 2.3. The 
ambient air quality monitoring data completeness requirements are met 
when quarterly data capture rates for all four quarters in a calendar 
year over a three-year period are at least 75 percent. For purposes of 
this proposal, we reviewed the data for the 2017-2019 period for 
completeness and determined that the PM10 data met the 
completeness criterion for all 12 quarters at the Yuma Supersite 
PM10 monitoring site in the Yuma NAA.\17\
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    \17\ EPA, AQS ``Design Value Report,'' dated March 31, 2021. 
This report is included in the docket.
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    The Arizona Department of Environmental Quality (ADEQ) is the 
governmental agency with the authority and responsibilities under the 
State's laws for collecting ambient air quality data for the Yuma NAA. 
ADEQ submits annual monitoring network plans to the EPA.\18\ These 
plans discuss the status of the ambient air monitoring network, as 
required under 40 CFR part 58. The EPA reviews these annual network 
plans for compliance with the applicable reporting requirements in 40 
CFR 58.10. With respect to PM10, the EPA has found that the 
2018-2020 annual network plans submitted by ADEQ, which reflect the 
network during the 2017-2019 design value period, met the applicable 
requirements under 40 CFR part 58.\19\ Furthermore, we concluded from 
our 2018 technical systems audit of ADEQ's ambient air quality 
monitoring program that the ambient air monitoring network currently 
meets or exceeds the requirements for the minimum number of monitoring 
sites designated as SLAMS for PM10 in the Yuma NAA.\20\ ADEQ 
certifies annually that the data it submits to AQS are quality-assured 
and has done so for each year relevant to our proposed action, 2017-
2019.\21\
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    \18\ See, e.g., ``State of Arizona Air Monitoring Network Plan 
for the Year 2020.'' Copies of Arizona's Annual Network Plans for 
2018-2020 are included in the docket.
    \19\ See, e.g., letter dated November 8, 2019, from Gwen 
Yoshimura, Manager, EPA Region IX, Air Quality Analysis Office, to 
Daniel Czecholinksi, Acting Director, Air Quality Division, ADEQ. 
Copies of EPA letters responding to Arizona's Annual Network Plans 
for 2018-2020 are included in the docket.
    \20\ Letter dated April 25, 2019, from Elizabeth Adams, 
Director, EPA Region 9 Air Division to Timothy Franquist, Director, 
Air Quality Division, ADEQ, enclosure titled ``Technical Systems 
Audit of the Ambient Air Monitoring Program: Arizona Department of 
Environmental Quality, April 2-April 6, 2018,'' Network Requirements 
section, 8.
    \21\ See, e.g., letter dated April 13, 2020, from Daniel 
Czecholinksi, Director, Air Quality Division, ADEQ, to Gwen 
Yoshimura, Manager, EPA Region IX, Air Quality Analysis Office. 
Copies of ADEQ certifications and their respective transmittal 
letters for years 2017-2019 are included in the docket.
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    Table 1 provides the 2019 p.m.10 design value for the 
Yuma Supersite, the sole regulatory monitoring site measuring ambient 
PM10 within the Yuma NAA, expressed as a single value 
representing the average expected annual exceedances over the three-
year period, 2017-2019. The PM10 data show that the design 
value is greater than 1.0 estimated annual average exceedances of the 
1987 24-hour PM10 NAAQS. Consequently, the EPA proposes to 
determine, based upon three years of complete, quality-assured and 
certified data from 2017-2019, that the Yuma NAA is no longer attaining 
the 1987 24-hour PM10 NAAQS.

 Table 1--2017-2019 Design Value for the 1987 24-Hour PM10 NAAQS for the
                                Yuma NAA
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                                                  AQS
             Monitoring site                 identification     Design
                                                  No.            value
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Yuma Supersite...........................       04-027-8011         5.7
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Source: EPA, AQS ``Design Value Report,'' dated March 31, 2021, 15.

    We have also reviewed preliminary 2020 data, which indicate that 
the Yuma NAA had a 2018-2020 design value of 5.4.\22\ This preliminary 
design value

[[Page 29221]]

also does not show attainment of the 1987 24-hour PM10 NAAQS 
and is therefore consistent with the proposed determination. We also 
reviewed preliminary data from the Yuma Supersite monitor for 2021, 
which is not a full year of data.\23\ As of March 31, 2021, there were 
no exceedances in 2021. We note, however, that even with no exceedances 
in 2021, given the number of expected exceedances in the certified year 
2019, plus those in the preliminary year 2020, the 2021 three-year 
preliminary design value violates the NAAQS and is therefore also 
consistent with our proposed determination.
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    \22\ EPA, AQS ``Design Value Report,'' dated March 3, 2021.
    \23\ Id.
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III. Proposed Action and Request for Public Comment

    Based on our proposed determination that the Yuma NAA is no longer 
attaining the 1987 24-hour PM10 NAAQS, we propose to rescind 
the clean data determination for the Yuma NAA and reinstate the 
requirements that were suspended under that determination. We 
anticipate that Arizona's submission of a new, approvable Moderate 
nonattainment plan in response to the ``SIP call'' discussed below 
would satisfy these obligations.
    In addition, we propose to find, pursuant to CAA section 110(k)(5), 
that the Arizona SIP is substantially inadequate to attain or maintain 
the 1987 24-hour PM10 NAAQS in the Yuma NAA. This proposed 
finding is based both on the most recent monitoring data discussed in 
section II of this document, as well as longer-term air quality trends 
in the Yuma NAA. In particular, we note that the Yuma NAA has had a 
violating design value for the 1987 24-hour PM10 NAAQSs 
every year since issuance of the clean data determination in 2006.\24\ 
Collectively, these recent and longer term monitoring data indicate 
that the current Arizona SIP is substantially inadequate to attain or 
maintain the 1987 24-hour PM10 NAAQS in the Yuma NAA.
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    \24\ Id.
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    In order to address this inadequacy, we propose to issue a SIP call 
under CAA section 110(k)(5), requiring the State to submit a SIP 
revision establishing that the Yuma NAA meets the applicable 
nonattainment plan requirements of the CAA for Moderate PM10 
NAAs.\25\ These requirements include: (i) An approved permit program 
for construction of new and modified major stationary sources; \26\ 
(ii) a demonstration that the plan provides for attainment by no later 
than the applicable Moderate area attainment date or a demonstration 
that attainment by that date is impracticable; \27\ (iii) provisions 
for the implementation of reasonably available control measures (RACM) 
and reasonably available control technology (RACT); \28\ (iv) 
quantitative milestones that will be used to evaluate compliance with 
the requirement to demonstrate reasonable further progress (RFP); \29\ 
(v) evaluation and regulation of PM10 precursors; \30\ (vi) 
a description of the expected annual incremental reductions in 
emissions that will demonstrate RFP; \31\ (vii) emissions inventories, 
as necessary; \32\ (viii) other control measures besides RACM and RACT 
as may be needed for attainment; \33\ (ix) contingency measures,\34\ 
and (x) a motor vehicle emissions budget for the purpose of determining 
the conformity of transportation programs and plans developed by state 
transportation agencies.\35\ The EPA's longstanding guidance on these 
statutory requirements is embodied in the ``The General Preamble for 
Implementation of Title I of the Clean Air Act (CAA) Amendments.'' \36\
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    \25\ See CAA section 110(k)(5) (``Any finding under this 
paragraph shall, to the extent the Administrator deems appropriate, 
subject the State to the requirements of this chapter to which the 
State was subject when it developed and submitted the plan for which 
such finding was made . . .'').
    \26\ CAA section 189(a)(1)(A).
    \27\ CAA section 189(a)(1)(B).
    \28\ CAA section 189(a)(1)(C).
    \29\ CAA section 189(c).
    \30\ CAA section 189(e).
    \31\ CAA section 172(c)(2).
    \32\ CAA section 172(c)(3).
    \33\ CAA section 172(c)(6).
    \34\ CAA section 172(c)(9).
    \35\ 40 CFR 93.102(b)(1). Effective June 27, 2007 (see 72 FR 
32295, June 12, 2007), the EPA found adequate for transportation 
conformity purposes the motor vehicle emissions budgets in the Yuma 
PM10 Maintenance Plan (August 2006). However, if we take 
final action to withdraw the clean data determination and issue a 
SIP call, we expect also to reverse our previous finding to a 
finding of inadequacy pursuant to 40 CFR 93.118(f)(1)(vi). Our 
inadequacy finding for the motor vehicle emissions budget would 
require transportation agencies to determine conformity using 
interim emission tests pursuant to 40 CFR 93.119, instead of the 
current practice of using the past maintenance plan motor vehicle 
emissions budgets as part of a budgets test.
    \36\ 57 FR 13498 (April 16, 1992).
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    We propose to require Arizona to submit this Moderate nonattainment 
plan SIP submission within 18 months of finalizing the SIP call, which 
is the maximum time permitted under CAA 110(k)(5). This is longer than 
the original Moderate nonattainment plan submittal deadline of one year 
from the date of the 1990 CAA Amendments under CAA 189(a)(2)(A), but is 
in line with the deadline specified in CAA 189(a)(2)(B) for other PM 
nonattainment areas.\37\ Similarly, because the original maximum 
attainment date for this area was December 31, 1994 (approximately four 
years from the original designation),\38\ we propose, pursuant to CAA 
110(k)(5), that the new attainment date shall be as expeditious as 
practicable, but no later than December 31, 2025.\39\ In line with this 
proposed attainment date, we propose to require implementation of RACM/
RACT by no later than January 1, 2025.\40\ Lastly, in the event we 
finalize the above proposals, we propose to reverse our previous budget 
adequacy finding to a finding of inadequacy pursuant to 40 CFR 
93.118(f)(1)(vi).
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    \37\ CAA section 189(a)(2).
    \38\ CAA section 188(c)(1).
    \39\ CAA section 110(k)(5), ``the Administrator may adjust any 
dates applicable under such requirements as appropriate (except that 
the Administrator may not adjust any attainment date prescribed 
under part D of this subchapter, unless such date has elapsed).''
    \40\ Given that exceedances of the 1987 24-hour PM10 
NAAQS in the Yuma NAA are often associated with high wind that could 
potentially qualify for treatment as ``natural events'' under the 
EPA's Exceptional Events Rule, we recommend RACM/RACT be fully 
implemented as early as January 1, 2023, so that anthropogenic 
sources would be reasonably controlled during the three-year period 
preceding the proposed attainment date. See, e.g., 40 CFR 
50.14(b)(5)(ii) (``The Administrator will consider high wind dust 
events to be natural events in cases where windblown dust is 
entirely from natural undisturbed lands in the area or where all 
anthropogenic sources are reasonably controlled . . .'').
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    The EPA is soliciting public comments on the issues discussed in 
this document. We will accept comments from the public on this proposal 
until the date listed in the DATES section above. We will consider 
these comments before taking final action.

IV. Statutory and Executive Order Reviews

    This action proposes a determination that the Yuma NAA is no longer 
attaining the 1987 PM10 NAAQS, based on the EPA's review of 
air quality data, and a SIP call under section 110(k)(5) of the CAA. 
Upon a finding that a SIP is deficient, section 110(k)(5) of the CAA 
directs the Agency to require the state to correct the deficiency. 
Therefore, this action does not impose additional requirements beyond 
those required by the CAA itself. For that reason, this 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);
     Does not impose an information collection burden under the 
provisions

[[Page 29222]]

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, this proposed action does not have Tribal implications 
as specified by Executive Order 13175 (65 FR 67249, November 9, 2000), 
because the SIP obligations discussed herein do not apply to Indian 
Tribes and thus this proposed action will not impose substantial direct 
costs on Tribal governments or preempt Tribal law. Nonetheless, the EPA 
intends to notify the Cocopah and Fort Yuma (Quechan) tribes, which 
have lands within the Yuma NAA.

List of Subjects in 40 CFR Part 52

    Environmental protection, Air pollution control, Incorporation by 
reference, Intergovernmental relations, Particulate Matter, Pollution.

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

    Dated: May 24, 2021.
Deborah Jordan,
Acting Regional Administrator, Region IX.
[FR Doc. 2021-11395 Filed 5-28-21; 8:45 am]
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