[Federal Register Volume 89, Number 188 (Friday, September 27, 2024)]
[Proposed Rules]
[Pages 79195-79203]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-22171]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R10-OAR-2024-0371; FRL-12159-01-R10]


Designation of Areas for Air Quality Planning Purposes; 
Redesignation Request and Associated Maintenance Plan for Whatcom 
County, WA 2010 SO2 Nonattainment Area

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: On July 25, 2024, the State of Washington (WA) submitted a 
request for the Environmental Protection Agency (EPA) to redesignate to 
attainment a portion of Whatcom County immediately surrounding the now 
permanently closed aluminum smelter, Intalco Aluminum LLC, which the 
EPA designated nonattainment for the 2010 sulfur dioxide 
(SO<INF>2</INF>) primary National Ambient Air Quality Standard (NAAQS). 
Washington also submitted a request for the EPA to approve a State 
Implementation Plan (SIP) revision containing a maintenance plan for 
the area. In response to this submittal, the EPA is proposing to take 
the following actions: determine that the Whatcom County (partial) 
SO<INF>2</INF> nonattainment area (NAA) is attaining the 2010 
SO<INF>2</INF> primary NAAQS; approve Washington's plan for maintaining 
attainment of the 2010 SO<INF>2</INF> primary NAAQS in the area; and 
redesignate the Whatcom County (partial) SO<INF>2</INF> NAA to 
attainment for the 2010 1-hour primary SO<INF>2</INF> NAAQS.

DATES: Written comments must be received on or before October 28, 2024.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R10-
OAR-2024-0371 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. 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 or 
other information the disclosure of which 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 confidential 
business information or multimedia submissions, and general guidance on 
making effective comments, please visit https://www.epa.gov/dockets/commenting-epa-dockets.

FOR FURTHER INFORMATION CONTACT: Jeff Hunt, EPA Region 10, 1200 Sixth 
Avenue, Suite 155, Seattle, WA 98101, at (206) 553-6357 or 
<a href="/cdn-cgi/l/email-protection#9df5e8f3e9b3f7f8fbfbddf8edfcb3faf2eb"><span class="__cf_email__" data-cfemail="4e263b203a60242b28280e2b3e2f60292138">[email protected]</span></a>.

SUPPLEMENTARY INFORMATION: Throughout this document, the use of ``we'' 
and ``our'' means the EPA.

I. What is the background for the EPA's proposed actions?

    On June 22, 2010, the EPA published a new 1-hour primary 
SO<INF>2</INF> NAAQS of 75 parts per billion (ppb), which is met at an 
ambient air quality monitoring site when the 3-year average of the 
annual 99th percentile of daily maximum 1-hour average concentrations 
does not exceed 75 parts per billion (ppb), as determined in accordance 
with appendix T of 40 CFR part 50 (75 FR 35520). Under Clean Air Act 
(CAA) section 107(d)(1), the EPA is required to designate areas as 
``nonattainment,'' ``attainment,'' or ``unclassifiable'' within two 
years of establishing a new or revising an existing standard. As part 
of this process, states must submit recommendations for area 
designations and boundaries to the EPA within one year of the effective 
date of the standard. In 2011, Washington State, like many states 
across the nation, did not have sufficient SO<INF>2</INF> monitoring 
data for specific stationary sources that may cause or contribute to 
violations of the revised SO<INF>2</INF> NAAQS and recommended that all 
areas in the state be designated as unclassifiable. In response to the 
lack of sufficient SO<INF>2</INF> monitoring data across the nation, 
the EPA promulgated the Data Requirements Rule (DRR) on August 21, 2015 
(80 FR 51052), which established a phased-in approach for state air 
agencies to characterize air quality via additional monitoring or 
modeling in areas associated with sources meeting certain criteria. In 
addition to the original round of nonattainment designations published 
on August 5, 2013 (78 FR 47191), the EPA promulgated three subsequent 
rounds of designations in 2016 (81 FR 45039, July 12, 2016), 2018 (83 
FR1098, January 9, 2018), and 2021 (86 FR 16055, March 26, 2021), as 
information to characterize air quality became available. The EPA 
designated Whatcom County (partial), Washington (also referred to as 
the ``nonattainment area'' or ``area'') as nonattainment effective 
April 30, 2021, as part of the Agency's Round 4 designations (86 FR 
16055, March 26, 2021).
    In the case of Washington, the EPA and the Washington Department of 
Ecology (Ecology) identified the Alcoa Intalco Aluminum LLC (Intalco) 
facility, located in the Cherry Point Industrial Area in Whatcom 
County, as emitting 2,000 tons or more of SO<INF>2</INF> annually, 
which triggered the DRR requirement for additional modeling or 
monitoring to characterize air quality in the area. Washington chose to 
meet this DRR requirement via the establishment of monitoring at the 
Intalco facility beginning on January 1, 2017. Based on the monitoring 
data established under the DRR, the Ferndale Mountain View Road monitor 
(AQS ID 53-073-0017) violated the 75 ppb level of the revised 1-hour 
primary SO<INF>2</INF> NAAQS with a 2017-2019 design value of 106 
ppb.\1\ The state did not send an updated formal designation 
recommendation for Whatcom County. However, Ecology, in collaboration 
with Northwest Clean Air Agency (NWCAA), submitted a technical report 
and modeling analysis on June 12, 2020, to help inform the EPA's 
nonattainment boundary determination using data from the monitors that 
were installed pursuant to

[[Page 79196]]

the DRR. Given that the state did not provide a formal recommendation 
for the boundary, the EPA conducted an extensive review of the 
submitted modeling to develop sufficient evidence to support the 
determination of a nonattainment boundary. The nonattainment boundary 
must contain all of the area where the NAAQS are not attained and all 
areas that contribute to the violations. Based on our review, the EPA 
determined that the state's modeling assessment was reliable for 
determining the extent of the area of violation of the 1-hour primary 
SO<INF>2</INF> NAAQS. Specifically, we agreed that the region of 
violation was most likely due to plume downwash at the Intalco facility 
during certain wind conditions, that the modeled area of violation did 
not extend far from the Intalco facility fence line, that the gradient 
of concentration near the areas of violation was steep, quickly 
dropping with distance from the Intalco facility fence line, and that 
other nearby industrial facilities did not sufficiently contribute to 
violations of the 1-hour primary SO<INF>2</INF> NAAQS to warrant 
inclusion in the NAA boundary. In our final nonattainment boundary 
determination, we concurred with Ecology and NWCAA's view that the 
boundary should be drawn to encompass the cause of the SO<INF>2</INF> 
violations, the Intalco facility. However, we used a simpler 
nonattainment boundary consisting of four Universal Transverse Mercator 
(UTM) coordinates instead of the various roadways and property lines 
suggested by NWCAA in a June 9, 2020, letter. For more information 
about the specific modeling and the EPA's analysis, please see 
``Appendix A Whatcom County SO<INF>2</INF> Area Designation'' included 
in the docket for this action.
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    \1\ The design value is the metric used for determining 
compliance with the SO<INF>2</INF> NAAQS under appendix T of 40 CFR 
part 50.
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    In response to the EPA's designation of the NAA, Washington 
submitted an attainment plan on December 15, 2022, to the EPA for 
approval. This plan and associated order required significant upgrades 
to the Intalco facility including installation and operation of a new 
SO<INF>2</INF> wet scrubber.\2\ Subsequently, on March 16, 2023, Alcoa 
Corporation publicly announced their plans to permanently close the 
Intalco facility.\3\ Ecology issued a notice of intent to revoke the 
associated minor new source review (NSR) and Title V Operating Permits 
on November 30, 2023, which became effective December 7, 2023.\4\ Under 
Revised Code of Washington (RCW) and Washington Administrative Code 
(WAC), Intalco cannot operate the facility without first obtaining a 
new Title V operating permit and applicable NSR permits, including a 
demonstration of compliance with the 2010 1-hour SO<INF>2</INF> NAAQS. 
Since the 2022 attainment plan, which imposed specific control 
requirements on Intalco, became functionally moot with the 2023 
permanent closure of the facility, Ecology proceeded directly to 
submitting a redesignation request and maintenance plan for the area. 
Upon the EPA's final approval of the redesignation request and 
maintenance plan for the area, Ecology intends to withdraw the now 
outdated 2022 attainment plan. The EPA is not proposing to act on the 
2022 attainment plan in this action.
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    \2\ See 202_Intalco Sulfur Dioxide Attainment Plan_2202035.pdf, 
included in the docket for this action.
    \3\ See Appendix A of state submittal included in the docket for 
this action.
    \4\ Id, November 30, 2023, from James DeMay to Tia Daulph, 
``Termination of Title V Air Operating Permit No. 0002950 and Notice 
of Construction Orders, Compliance Orders, and Agreed Orders'' and 
December 7, 2023, from Tia Daulph to James DeMay, ``Re: Termination 
of Title V Air Operating Permit No. 0002950'' included in the docket 
for this action.
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II. What are the criteria for redesignation?

    The CAA provides the requirements for redesignating a NAA to 
attainment. Specifically, section 107(d)(3)(E) of the CAA allows for 
redesignation of a NAA provided that: (1) the Administrator determines 
that the area has attained the applicable NAAQS; (2) the Administrator 
has fully approved the applicable implementation plan for the area 
under section 110(k); (3) the Administrator determines that the 
improvement in air quality is due to permanent and enforceable 
reductions in emissions resulting from implementation of the applicable 
SIP and applicable Federal air pollutant control regulations and other 
permanent and enforceable reductions; (4) the Administrator has fully 
approved a maintenance plan for the area as meeting the requirements of 
section 175A; and (5) the State containing such area has met all 
requirements applicable to the area for purposes of redesignation under 
section 110 and part D of the CAA.
    On April 16, 1992, the EPA provided guidance on redesignation in 
the General Preamble for the Implementation of title I of the CAA 
Amendments of 1990 (57 FR 13498) and supplemented this guidance on 
April 28, 1992 (57 FR 18070). The EPA has provided further guidance on 
processing redesignation requests in several guidance documents. For 
the purposes of this action, the EPA will be referencing two of these 
documents: (1) the September 4, 1992, Memorandum from John Calcagni 
titled ``Procedures for Processing Requests to Redesignate Areas to 
Attainment,'' (hereafter referred to as the ``Calcagni Memo''); and (2) 
the April 23, 2014, Memorandum from Stephen D. Page titled ``Guidance 
for 1-Hour SO<INF>2</INF> Nonattainment Area SIP Submissions,'' 
(hereafter referred to as ``2014 SO<INF>2</INF> NAA Guidance'').

III. What is the EPA's analysis of the request?

    The EPA's evaluation of Washington's redesignation request and 
maintenance plan was based on consideration of the five redesignation 
criteria provided under CAA section 107(d)(3)(E).

Criteria (1)--The Whatcom County (Partial) SO2 Nonattainment Area Has 
Attained the 2010 1-Hour SO2 NAAQS

    For redesignating a NAA, the CAA requires the EPA to determine that 
the area has attained the applicable NAAQS (CAA section 
107(d)(3)(E)(i)). The two primary methods for evaluating ambient air 
quality impacted by SO<INF>2</INF> emissions are through dispersion 
modeling and air quality monitoring. For SO<INF>2</INF>, an area may be 
considered attaining the 2010 1-hour SO<INF>2</INF> NAAQS if it meets 
the NAAQS as determined in accordance with 40 CFR 50.17 and appendix T 
of part 50, based on three complete, consecutive calendar years of 
quality-assured air quality monitoring data. To attain the NAAQS based 
on monitoring, the 3-year average of the annual 99th percentile (fourth 
highest value) of 1-hour daily maximum concentrations measured at each 
monitor within an area must be less than or equal to 75 ppb. The data 
must be collected and quality-assured in accordance with 40 CFR part 58 
and recorded in the EPA Air Quality System (AQS). The EPA's 
determination of attainment can be based on monitoring data alone, 
without the need for dispersion modeling analyses, if the air agency 
provides an analysis demonstrating that the monitor(s) for the affected 
area is located in the area of maximum ambient concentration of 
SO<INF>2</INF>.\5\
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    \5\ See 2014 SO<INF>2</INF> NAA Guidance, at 62.
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    In this action, the EPA is proposing to determine that the Whatcom 
County (partial) SO<INF>2</INF> nonattainment area is attaining the 
2010 1-hour SO<INF>2</INF> NAAQS. The EPA reviewed SO<INF>2</INF> 
monitoring data from the two monitoring stations inside the Whatcom 
County (partial) SO<INF>2</INF> nonattainment area, the Ferndale-
Mountain View Road station (AQS Site

[[Page 79197]]

ID 53-073-0017) and the Ferndale-Kickerville Road station (AQS Site ID 
53-073-0013). The monitoring station data have been quality-assured, 
are recorded in the EPA's Air Quality System (AQS), and indicate that 
the area is attaining the 2010 1-hour SO<INF>2</INF> NAAQS. The fourth-
highest 1-hour SO<INF>2</INF> values at the monitoring stations for the 
3-year averages of these values (i.e., design values), are summarized 
in Table 1, below.

                         Table 1--Whatcom County (Partial) Monitored SO2 Concentrations
                                                      [ppb]
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                                                          2021 99th     2022 99th     2023 99th      2021-2023
                        Station                          Percentile    Percentile    Percentile    Design value
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Ferndale-Mountain View Road...........................           2.6           3.3           4.4               3
Ferndale-Kickerville Road.............................           2.4           3.1           4.4               3
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    As shown, the 3-year design values for 2021-2023 at the monitoring 
stations are well below the 2010 1-hour SO<INF>2</INF> NAAQS. 
Concentrations of SO<INF>2</INF> at these monitoring stations decreased 
significantly from the 2017-2019 design value of 106 ppb following the 
shutdown of the Intalco facility. Since the facility last operated in 
July 2020, 99th percentile values at the monitoring stations have not 
exceeded 4.4 ppb SO<INF>2</INF>. These low values are anticipated to be 
consistent, as the state demonstrated in its analysis that 
SO<INF>2</INF> emissions since 2020 have consistently decreased to 
levels well below the 2010 1-hour SO<INF>2</INF> NAAQS during both 
curtailment and permanent closure of the Intalco facility.\6\
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    \6\ Whatcom County (partial) redesignation request, at pages 20-
22.
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    As part of Washington's 2022 attainment plan and 2024 redesignation 
request, Ecology submitted information to support a showing that the 
Ferndale-Mountain View Road monitor was sited in the area of maximum 
ambient SO<INF>2</INF> concentration within the Whatcom County 
(partial) SO<INF>2</INF> NAA in accordance with the 2014 SO<INF>2</INF> 
NAA Guidance. Ecology identified appropriate locations for the two 
Ferndale monitors in 2015 by running the AERMOD \7\ dispersion model 
using SO<INF>2</INF> actual emissions from Intalco.\8\ The EPA reviewed 
Washington's information regarding this showing in designating the area 
nonattainment in Round 4. We found that the state's modeling assessment 
was reliable for determining the extent of the area of violation of the 
1-hour SO<INF>2</INF> NAAQS. Specifically, we agreed that the region of 
violation was most likely due to plume downwash at the Intalco facility 
during certain wind conditions, that the modeled area of violation does 
not extend far from the Intalco facility fenceline, that the gradient 
of concentration near the areas of violation is steep, quickly dropping 
with distance from the Intalco facility fenceline, and that other 
nearby industrial facilities do not sufficiently contribute to 
violations of the SO<INF>2</INF> NAAQS to warrant inclusion in the 
nonattainment area boundary.\9\ With Intalco permanently closed, 
monitored SO<INF>2</INF> concentrations in the Whatcom County (partial) 
SO<INF>2</INF> nonattainment area are well below the 75 ppb standard.
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    \7\ AERMOD is one of the EPA's preferred and recommended 
dispersion models listed in the Guideline on Air Quality Models--
Appendix W to be used for State Implementation Plan (SIP) revisions 
for existing sources and for New Source Review (NSR) and Prevention 
of Significant Deterioration (PSD) programs. See https://www.epa.gov/scram/air-quality-dispersion-modeling-preferred-and-recommended-models.
    \8\ See 201_Appendix A Whatcom County SO<INF>2</INF> Area 
Designation and 203 Appendix C Intalco SO<INF>2</INF> Attainment 
Modeling Report, included in the docket for this action.
    \9\ Id.
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    In this action, the EPA is proposing to determine that the Whatcom 
County (partial) SO<INF>2</INF> nonattainment area is attaining the 
2010 1-hour SO<INF>2</INF> NAAQS, and therefore meets the requirements 
of CAA section 107(d)(3)(E)(i). If the 3-year design value exceeds the 
NAAQS prior to the EPA taking action in response to the state's 
request, the EPA will not take final action to approve the 
redesignation request.\10\
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    \10\ See 2014 SO<INF>2</INF> NAA Guidance, at 56.
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    Because the EPA's analysis in determining whether an area has 
attained under the clean data policy is the same as its analysis under 
the first redesignation criterion, the EPA is also here proposing that 
the Whatcom County (partial) SO<INF>2</INF> nonattainment area 
qualifies for a determination of attainment under the clean data 
policy, based on the 2021-2023 monitoring data at the two Ferndale 
monitoring stations. The clean data policy represents the EPA's 
interpretation that certain requirements of part D of title I of the 
Act are suspended for areas that are currently attaining the NAAQS. The 
requirements that are suspended in an area attaining the standard 
include the requirements to submit an ``attainment SIP'' that provides 
for: attainment of the NAAQS; implementation of all reasonably 
available control measures (RACM); reasonable further progress (RFP); 
and implementation of contingency measures for failure to meet 
deadlines for RFP and attainment. In the 2014 SO<INF>2</INF> NAA 
Guidance, the EPA explained our intention to apply the EPA's clean data 
policy to the 2010 SO<INF>2</INF> primary NAAQS.\11\
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    \11\ Id. at 52.
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    In the event that the EPA does not finalize the proposed 
redesignation, the EPA may choose to finalize the clean data 
determination, thereby suspending attainment planning-related 
requirements for the area for as long as the area continues to attain 
the standard.

Criteria (2)--Washington Has a Fully Approved SIP Under Section 110(k) 
and Criteria (5)--Washington Has Met All Applicable Requirements Under 
Section 110 and Part D of Title I of the CAA

    For redesignating a nonattainment area to attainment under a NAAQS, 
the CAA requires the EPA to determine that the state has met all 
applicable requirements for that NAAQS under section 110 and part D of 
title I of the CAA (CAA section 107(d)(3)(E)(v)) and that the state has 
a fully approved SIP under section 110(k) for that NAAQS for the area 
(CAA section 107(d)(3)(E)(ii)). The EPA proposes to find that 
Washington has met all applicable SIP requirements for the Whatcom 
County (partial) SO<INF>2</INF> nonattainment area for the 2010 
SO<INF>2</INF> NAAQS under section 110 of the CAA (general SIP 
requirements) for purposes of redesignation. Additionally, the EPA 
proposes to find that the Washington SIP satisfies the criterion that 
it meets applicable SIP requirements for purposes of redesignation 
under part D of title I of the CAA in accordance with section 
107(d)(3)(E)(v). Further, the EPA proposes to determine that the SIP is 
fully approved with respect to all requirements applicable for the 2010 
SO<INF>2</INF> NAAQS for purposes of redesignation in accordance with 
section 107(d)(3)(E)(ii). In making the determinations, the EPA 
ascertained

[[Page 79198]]

which requirements are applicable to the Whatcom County (partial) 
SO<INF>2</INF> nonattainment area and, if applicable, that they are 
fully approved under section 110(k).
a. The Whatcom County (Partial) SO<INF>2</INF> Nonattainment Area Has 
Met All Applicable Requirements Under Section 110 and Part D of the CAA
    General SIP Requirements. General SIP elements and requirements are 
delineated in section 110(a)(2) of title I, part A of the CAA. These 
requirements include, but are not limited to, the following: submittal 
of a SIP that has been adopted by the state after reasonable public 
notice and hearing; provisions for establishment and operation of 
appropriate procedures needed to monitor ambient air quality; 
implementation of a source permit program; provisions for the 
implementation of part C requirements (Prevention of Significant 
Deterioration (PSD)) and provisions for the implementation of part D 
requirements (New Source Review (NSR) permit programs); provisions for 
air pollution modeling; and provisions for public and local agency 
participation in planning and emission control rule development.
    Section 110(a)(2)(D) requires that SIPs contain certain measures to 
prevent sources in a state from significantly contributing to air 
quality problems in another state. To implement this provision, the EPA 
has required certain states to establish programs to address the 
interstate transport of air pollutants. The section 110(a)(2)(D) 
requirements for a state are not linked with a particular nonattainment 
area's designation and classification in that state. The EPA believes 
that the requirements linked with a particular nonattainment area's 
designation and classifications are the relevant measures to evaluate 
in reviewing a redesignation request. The transport SIP submittal 
requirements, where applicable, continue to apply to a state regardless 
of the designation of any one particular area in the state. Thus, the 
EPA does not believe that the CAA's interstate transport requirements 
should be construed to be applicable requirements for purposes of 
redesignation.
    In addition, the EPA believes other section 110 elements that are 
neither connected with nonattainment plan submissions nor linked with 
an area's attainment status are applicable requirements for purposes of 
redesignation. The area will still be subject to these requirements 
after the area is redesignated. The section 110 and part D requirements 
which are linked with a particular area's designation and 
classification are the relevant measures to evaluate in reviewing a 
redesignation request. This approach is consistent with the EPA's 
existing policy on applicability (i.e., for redesignations) of 
conformity and oxygenated fuels requirements, as well as with section 
184 ozone transport requirements. See Reading, Pennsylvania, proposed 
and final rules (61 FR 53174-53176, October 10, 1996), (62 FR 24826, 
May 7, 2008); Cleveland-Akron-Loraine, Ohio, final rule (61 FR 20458, 
May 7,1996); and Tampa, Florida, final rule (60 FR 62748, December 7, 
1995). See also the discussion on this issue in the Cincinnati, Ohio, 
redesignation (65 FR 37890, June 19, 2000), and in the Pittsburgh, 
Pennsylvania, redesignation (66 FR 0399, October 19, 2001).
    Title I, Part D, Applicable SIP Requirements. Section 172(c) of the 
CAA sets forth the basic requirements of attainment plans for NAAs that 
are required to be submitted pursuant to section 172(b). Subpart 5 of 
part D, which includes section 191 and 192 of the CAA, establishes 
requirements for SO<INF>2,</INF> nitrogen dioxide and lead NAAs. A 
thorough discussion of the requirements contained in sections 172(c) 
can be found in the General Preamble for Implementation of Title I (57 
FR 13498, April 16, 1992).
    Section 172(c)(1) requires the plans for all NAAs to provide for 
the implementation of all RACM as expeditiously as practicable and to 
provide for attainment of the NAAQS. The EPA interprets this 
requirement to impose a duty on all nonattainment areas to consider all 
available control measures and to adopt and implement such measures as 
are reasonably available for implementation in each area as components 
of the area's attainment demonstration. Under section 172, states with 
nonattainment areas must submit plans providing for timely attainment 
and meeting a variety of other requirements.
    The EPA's longstanding interpretation of the nonattainment planning 
requirements of section 172 is that once an area is attaining the 
NAAQS, those requirements are not ``applicable'' for purposes of CAA 
sections 107(d)(3)(E)(ii) and (v) and therefore, need not be approved 
into the SIP before the EPA can redesignate the area. In the 1992 
General Preamble for Implementation of Title I, the EPA set forth its 
interpretation of applicable requirements for purposes of evaluating 
redesignation requests when an area is attaining a standard. See 57 FR 
13498, 13564 (April 16, 1992). The EPA noted that the requirements for 
RFP and other measures designed to provide for attainment do not apply 
in evaluating redesignation requests because those nonattainment 
planning requirements ``have no meaning'' for an area that has already 
attained the standard. Id. This interpretation was also reiterated in 
the 1992 Calcagni Memo and consistently applied in many proposed and 
final redesignation actions since. The EPA's understanding of section 
172 also forms the basis of its Clean Data Policy, which was 
articulated with regard to SO<INF>2</INF> in the 2014 SO<INF>2</INF> 
NAA Guidance and suspends a state's obligation to submit most of the 
attainment planning requirements that would otherwise apply, including 
an attainment demonstration and planning SIPs to provide for RFP, RACM, 
and contingency measures under section 172(c)(9). Courts have upheld 
the EPA's interpretation of section 172(c)(1) for ``reasonably 
available'' control measures and control technology as meaning only 
those controls that advance attainment, which precludes the need to 
require additional measures where an area is already attaining. NRDC v. 
EPA, 571 F.3d 1245, 1252 (D.C. Cir. 2009); Sierra Club v. EPA, 294 F.3d 
155, 162 (D.C. Cir. 2002); Sierra Club v. EPA, 314 F.3d 735, 744 (5th 
Cir. 2002); Sierra Club v. EPA, 375 F.3d 537 (7th Cir. 2004). But see 
Sierra Club v. EPA, 793 F.3d 656 (6th Cir. 2015).
    Therefore, because the design values for 2021-2023 are well below 
the NAAQS in the Whatcom County (partial) SO<INF>2</INF> NAA, no 
additional measures are needed to provide for attainment, and section 
172(c)(1) requirements for an attainment demonstration and RACM are not 
part of the ``applicable implementation plan'' required to have been 
approved prior to redesignation per CAA section 107(d)(3)(E)(ii). The 
other section 172 requirements that are designed to help an area 
achieve attainment--the section 172(c)(2) requirement that 
nonattainment plans contain provisions promoting reasonable further 
progress, the requirement to submit the section 172(c)(9) contingency 
measures that would apply if the area fails to timely attain, and the 
section 172(c)(6) requirement for the SIP to contain control measures 
necessary to provide for attainment of the NAAQS--are also not required 
to be approved as part of the ``applicable implementation plan'' for 
purposes of satisfying CAA section 107(d)(3)(E)(ii).
    Section 172(c)(3) requires submission and approval of a 
comprehensive, accurate, and current inventory of actual emissions. The 
requirement for an emission inventory can be satisfied by

[[Page 79199]]

meeting the inventory requirements of the maintenance plan.\12\ Ecology 
submitted an emissions inventory as part of the maintenance plan for 
the Whatcom County (partial) SO<INF>2</INF> nonattainment area, and 
this inventory will be discussed further in the maintenance plan 
portion of this proposed action.
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    \12\ Calcagni Memo at 6.
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    Section 172(c)(4) requires the identification and quantification of 
allowable emissions for major new and modified stationary sources to be 
allowed in an area, and section 172(c)(5) requires source permits for 
the construction and operation of new and modified major stationary 
sources anywhere in the nonattainment area. The EPA has determined 
that, since PSD requirements will apply after redesignation, areas 
being redesignated need not comply with the requirement that a NSR 
program be approved prior to redesignation, provided that the area 
demonstrates maintenance of the NAAQS without part D NSR. A more 
detailed rationale for this view is described in a memorandum from Mary 
Nichols, Assistant Administrator for Air and Radiation, dated October 
14, 1994, entitled ``Part D New Source Review Requirements for Areas 
Requesting Redesignation to Attainment.'' Ecology has demonstrated that 
the Whatcom County (partial) SO<INF>2</INF> nonattainment area will be 
able to maintain the NAAQS without part D NSR in effect, and therefore 
Washington need not have fully approved part D NSR programs prior to 
approval of the redesignation request. Nevertheless, we note that 
Washington's nonattainment NSR for major sources was last approved by 
the EPA on October 6, 2016 (81 FR 69386) and the NWCAA's nonattainment 
NSR for minor sources was last approved by the EPA on June 5, 2020 (85 
FR 36156). Both programs meet all relevant NSR requirements for 
SO<INF>2</INF>. Washington's PSD program for major sources will become 
effective in the Whatcom County (partial) SO<INF>2</INF> nonattainment 
area upon redesignation to attainment. Section 172(c)(7) requires the 
SIP to meet the applicable provisions of section 110(a)(2). As noted 
above, the EPA believes the Washington SIP meets the requirements of 
section 110(a)(2) applicable for purposes of redesignation.
    Section 176 Conformity Requirements. Section 176(c) of the CAA 
requires states to establish criteria and procedures to ensure that 
federally supported or funded projects conform to the air quality 
planning goals in the applicable SIP. The requirement to determine 
conformity applies to transportation plans, programs, and projects that 
are developed, funded, or approved under title 23 of the United States 
Code (U.S.C.) and the Federal Transit Act (transportation conformity) 
as well as to all other federally supported or funded projects (general 
conformity). State transportation conformity SIP revisions must be 
consistent with Federal conformity regulations relating to 
consultation, enforcement, and enforceability that the EPA promulgated 
pursuant to its authority under the CAA.
    The EPA interprets the conformity SIP requirements as not applying 
for purposes of evaluating a redesignation request under section 107(d) 
because, like other requirements listed above, state conformity rules 
are still required after redesignation and Federal conformity rules 
apply where state rules have not been approved. See Wall v. EPA, 265 
F.3d 426 (6th Cir. 2001) (upholding this interpretation); see also 60 
FR 62748 (December 7, 1995) (redesignation of Tampa, Florida).
    For these reasons, the EPA proposes to find that Washington has 
satisfied all applicable requirements for purposes of redesignation of 
the Whatcom County (partial) SO<INF>2</INF> nonattainment area under 
section 110 and part D of title I of the CAA.
b. The Whatcom County (Partial) SO<INF>2</INF> Nonattainment Area Has a 
Fully Approved Applicable SIP Under Section 110(k) of the CAA
    The EPA has fully approved the applicable Washington SIP for the 
Whatcom County (partial) area under section 110(k) of the CAA for all 
requirements applicable for purposes of redesignation. As indicated 
above, the EPA believes that the section 110 elements that are neither 
connected with nonattainment plan submissions nor linked to an area's 
nonattainment status are not applicable requirements for purposes of 
redesignation. The EPA has approved all part D requirements applicable 
under the 2010 SO<INF>2</INF> NAAQS, as identified above, for purposes 
of this redesignation.

Criteria (3)--The Air Quality Improvement in the Whatcom County 
(Partial) SO2 Nonattainment Area Is Due to Permanent and Enforceable 
Reductions in Emissions

    For redesignating a nonattainment area to attainment, the CAA 
requires the EPA to determine that the air quality improvement in the 
area is due to permanent and enforceable reductions in emissions 
resulting from implementation of the SIP, applicable Federal air 
pollution control regulations, and other permanent and enforceable 
reductions (CAA section 107(d)(3)(E)(iii)). The EPA proposes to find 
that Washington has demonstrated that the observed air quality 
improvement in the Whatcom County (partial) SO<INF>2</INF> NAA is due 
to permanent and enforceable reductions in emissions. Specifically, the 
EPA considers the shutdown of the Intalco facility, identified as the 
key contributor to the SO<INF>2</INF> NAAQS violations at the Ferndale-
Mountain View Road monitor,\13\ to be both permanent and enforceable. 
Given the well-established correlation of much lower SO<INF>2</INF> 
emissions at the two Ferndale monitors during periods when Intalco has 
not operated and the very low SO<INF>2</INF> concentrations following 
the facility's permanent shutdown, the EPA anticipates that the area 
will continue to attain the SO<INF>2</INF> NAAQS. As stated in the 
Calcagni Memo, ``Emission reductions from source shutdowns can be 
considered permanent and enforceable to the extent that those shutdowns 
have been reflected in the SIP and all applicable permits have been 
modified accordingly.'' \14\ Ecology revoked Alcoa's Title V 
(operating) and NSR permits for the Intalco facility.\15\ The facility 
is now permanently closed, making its future operation impossible and 
thus displaying the permanence of the emissions reductions in the NAA. 
Any new sources that may come into being within the area would be 
required to demonstrate that their new SO<INF>2</INF> emissions would 
not interfere with attainment and maintenance of the 2010 1-hour 
primary SO<INF>2</INF> NAAQS. Therefore, the EPA is proposing to find 
that the air quality improvement in the Whatcom County (partial) 
SO<INF>2</INF> NAA is due to permanent and enforceable reductions in 
emissions.
---------------------------------------------------------------------------

    \13\ See EPA's final Technical Support Document (TSD) for the 
Whatcom County (partial) SO<INF>2</INF> nonattainment area, included 
in the docket for this action. See 201_Appendix A Whatcom County 
SO<INF>2</INF> Area Designation.pdf.
    \14\ Calcagni Memo at 10.
    \15\ Ecology's November 30, 2023, permit revocation letter is 
included in appendix A of the redesignation request, included in the 
docket for this action.
---------------------------------------------------------------------------

Criteria (4)--The Whatcom County (Partial) SO2 Nonattainment Area Has a 
Fully Approved Maintenance Plan Pursuant to Section 175A of the CAA

    To redesignate a NAA to attainment, the CAA requires the EPA to 
determine that the area has a fully approved maintenance plan pursuant 
to section 175A of the CAA (CAA section 107(d)(3)(E)(iv)). In 
conjunction with its

[[Page 79200]]

request to redesignate the Whatcom County (partial) SO<INF>2</INF> 
nonattainment area to attainment for the 2010 1-hour SO<INF>2</INF> 
NAAQS, Ecology submitted a SIP revision to provide for the maintenance 
of the 2010 1-hour SO<INF>2</INF> NAAQS for at least 10 years after the 
effective date of redesignation to attainment. The EPA is proposing to 
find that this maintenance plan for the area meets the requirements for 
approval under section 175A of the CAA.
a. What is required in a maintenance plan?
    CAA section 175A sets forth the elements of a maintenance plan for 
areas seeking redesignation from nonattainment to attainment. Under 
section 175A, the plan must demonstrate continued attainment of the 
applicable NAAQS for at least 10 years after the Administrator approves 
a redesignation to attainment. Eight years after the redesignation, the 
state must submit a revised maintenance plan demonstrating that 
attainment will continue to be maintained for the 10 years following 
the initial 10-year period. To address the possibility of future NAAQS 
violations, the maintenance plan must contain contingency measures as 
the EPA deems necessary to assure prompt correction of any future 2010 
1-hour SO<INF>2</INF> violations. The Calcagni Memo provides further 
guidance on the content of a maintenance plan, explaining that a 
maintenance plan should address five elements: The attainment emissions 
inventory, maintenance demonstration, monitoring, verification of 
continued attainment, and a contingency plan. As is discussed more 
fully below, the EPA is proposing to determine that Washington's 
maintenance plan includes all the necessary components and is thus 
proposing to approve it as a revision to the Washington SIP.
b. Attainment Emissions Inventory
    As part of a state's maintenance plan for a 2010 SO<INF>2</INF> 
NAA, the air agency should develop an attainment inventory to identify 
the level of emissions in the affected area which is sufficient to 
attain and maintain the SO<INF>2</INF> NAAQS.\16\ Washington selected 
2020 as the base year (i.e., attainment emissions inventory year) for 
developing an emissions inventory for SO<INF>2</INF> in the NAA through 
2033. The 2020 base year represents the most contemporaneous National 
Emissions Inventory (NEI) available. The 2020 base year also represents 
Intalco's final year of operation with facility emissions of 1,613 tons 
of SO<INF>2.</INF>
---------------------------------------------------------------------------

    \16\ See 2014 SO<INF>2</INF> NAA Guidance, at 66.
---------------------------------------------------------------------------

    In the 2019-2021 monitoring period, representative of the base 
year, the Ferndale-Mountain View Road monitor had a 3-year design value 
of 56 ppb and the Ferndale-Kickerville Road monitor had a 3-year design 
value of 44 ppb, both below the 75 ppb concentration of the 1-hour 
SO<INF>2</INF> NAAQS. The 2020 99th percentiles recorded at the two 
monitors are consistent with these low design values at 62.0 ppb and 
59.2 ppb, respectively. The EPA has therefore determined that this is a 
level sufficient to attain the 2010 1-hour SO<INF>2</INF> NAAQS and is 
proposing to find that the attainment inventory submitted as part of 
Washington's maintenance plan meets the ``Attainment Emissions 
Inventory'' requirement.
    The EPA notes that the permanent shutdown of Intalco has left the 
Whatcom County (partial) SO<INF>2</INF> NAA with no significant sources 
of SO<INF>2</INF>, and the maintenance plan for the area contains an 
emissions inventory which projects no significant SO<INF>2</INF> 
emissions in the NAA from 2020 through 2033. The EPA therefore does not 
anticipate emissions activity in the 2010 SO<INF>2</INF> nonattainment 
area that will approach 1,613 tons of SO<INF>2</INF>.

        Table 2--Base Year 2020 and Projection Years 2026 and 2033 SO2 Emissions for the Maintenance Area
                                                 [Tons per year]
----------------------------------------------------------------------------------------------------------------
                                                                                       2026            2033
                             Source                               2020 Base year    Projection      Projection
----------------------------------------------------------------------------------------------------------------
Alcoa Primary Metals Intalco Works..............................       1613.4000               0               0
Residential non-wood fuel use...................................          0.0026          0.0026          0.0026
Residential wood combustion (home heating)......................          0.0266          0.0266          0.0266
On-road mobile sources..........................................          0.0095          0.0095          0.0095
Ships (commercial marine vessels)...............................          0.0221          0.0221          0.0221
Railroad (locomotives)..........................................          0.0002          0.0002          0.0002
Non-road mobile equipment and vehicles (NEC)....................          0.0010          0.0010          0.0010
                                                                 -----------------------------------------------
    Total.......................................................      1,613.4620          0.0620          0.0620
----------------------------------------------------------------------------------------------------------------

c. Maintenance Demonstration
    An air agency may generally demonstrate maintenance of the NAAQS by 
either showing that future emissions of SO<INF>2</INF> will not exceed 
the level of the attainment inventory, or by modeling to show that the 
future mix of sources and emission rates will not cause a violation of 
the NAAQS.\17\ Washington has demonstrated maintenance by showing that 
future year emissions (through ``out year'' 2033) of SO<INF>2</INF> in 
the maintenance area are expected to remain near zero following the 
Intalco shutdown. Due to the small geographic scope of the 
nonattainment area surrounding the facility boundary (4.5 square 
miles), other contributing sources such as mobile sources and area 
sources are nearly nonexistent and are projected to remain constant 
through 2033. The EPA considers the inventory projection sufficient to 
attain and maintain the SO<INF>2</INF> NAAQS. The EPA is therefore also 
proposing to find that Washington's ``Maintenance Demonstration'' 
requirement is met based on this projected emissions inventory.
---------------------------------------------------------------------------

    \17\ See 2014 SO<INF>2</INF> NAA Guidance at 67.
---------------------------------------------------------------------------

d. Monitoring Network and Verification of Continued Attainment
    According to the Calcagni Memo, the state should continue to 
operate an appropriate air quality monitoring network to verify the 
attainment status of the area.\18\ In addition, the state must have the 
legal authority to implement and enforce all measures necessary to 
attain and maintain the NAAQS and the maintenance plan should contain 
provisions to track the progress of the maintenance plan.
---------------------------------------------------------------------------

    \18\ Calcagni Memo at 11.
---------------------------------------------------------------------------

    With respect to the monitoring network, Ecology maintains two 
SO<INF>2</INF> monitors in the nonattainment area:

[[Page 79201]]

Ferndale-Mountain View Road and the Ferndale-Kickerville Road. These 
monitors were included in Ecology's 2023 Ambient Air Monitoring Network 
Plan as microscale SLAMS monitors.\19\ EPA approved this network plan 
on November 16, 2023.\20\ As discussed in the EPA's 2020 designation of 
the area and the 2022 attainment plan included in the docket for this 
action, the Ferndale-Mountain View Road and the Ferndale-Kickerville 
Road SO<INF>2</INF> monitors were sited for the specific purpose of 
measuring building downwash impacts from the Intalco facility.\21\ With 
the closure of the Intalco facility, these monitors would not be 
considered to be sited in the area of maximum concentration if a new 
SO<INF>2</INF> emitting source were to locate to the area.
---------------------------------------------------------------------------

    \19\ Department of Ecology, State of Washington, 2023 Ambient 
Air Monitoring Network Plan, Publication 23-02-043, June 2023, at p. 
20.
    \20\ November 16, 2023, Letter from Debra Suzuki, Air Planning 
and State/Tribal Coordination Branch, EPA Region 10, to Jill 
Schulte, Ambient Air Monitoring Coordinator, Department of Ecology.
    \21\ See 201_Appendix A Whatcom County SO<INF>2</INF> Area 
Designation.pdf and 202_Intalco Sulfur Dioxide Attainment 
Plan_2202035.pdf, included in the docket for this action.
---------------------------------------------------------------------------

    Therefore, Ecology included in its maintenance plan a stepwise 
analytical process for deploying SO<INF>2</INF> monitors in the 
maintenance area and verifying continued attainment. Ecology's 
intentions with this process are twofold: (1) provide an alternative to 
maintaining the existing microscale monitors for the duration of the 
maintenance period and (2) providing a basis for potential future 
discontinuation of the two microscale Ferndale monitors under 40 CFR 
58.14(c)(3). Note, EPA is not proposing in this action to approve any 
discontinuation of any monitoring sites. Any future discontinuation of 
monitoring is subject to the approval procedures in 40 CFR part 58.
    Ecology lays out its plan for deploying monitors and verifying 
continued attainment in Chapter 6 Verification of Attainment, Control 
Measures, and Maintenance Demonstration of the maintenance plan. This 
plan builds upon Washington's SIP-approved minor and major NSR 
programs. Washington's SIP includes NWCAA Rule 300 which establishes 
the minor NSR program applicable to sources constructed or modified in 
the Ferndale Area. Under Rule 300, save for certain limited exemptions, 
sources with a potential to emit more than 2.0 tons per year (tpy) of 
SO<INF>2</INF> must obtain approval prior to construction.\22\ NWCAA 
may not approve construction or modification unless, among other 
things, the source will employ best available control technology and 
allowable emissions will not cause or contribute to a violation of any 
NAAQS.\23\ As to the latter, NWCAA may require modeling using EPA 
guidelines in appendix W of 40 CFR part 51 to determine whether 
construction and operation of the source will cause or contribute to a 
violation of any NAAQS.
---------------------------------------------------------------------------

    \22\ Rule 300.1(A); 300.4.
    \23\ Rule 300.9.
---------------------------------------------------------------------------

    Washington's SIP also includes a major new source review program to 
regulate the construction and modification of major sources constructed 
or modified in the Ferndale Area.\24\ In general, Washington's major 
NSR program incorporates by reference the Federal major NSR program at 
40 CFR 52.21. The major NSR program applies to sources with a potential 
to emit 100 tpy of any regulated NSR pollutant for certain listed 
source categories, and 250 tpy of any regulated NSR pollutant for 
unlisted sources. Regulated NSR pollutant includes pollutants for which 
the EPA has established a NAAQS.
---------------------------------------------------------------------------

    \24\ 40 CFR 52.2470(c); WAC 173-400-113 and WAC 173-400-700 
through 173-400-750.
---------------------------------------------------------------------------

    Similar to the minor NSR program, all sources subject to the major 
NSR program must obtain a permit before commencing construction. In 
order to obtain a permit, the source must, among other things, 
demonstrate the source will apply best available control technologies 
for each regulated NSR pollutant that the source has the potential to 
emit in significant amounts. In the case of SO<INF>2</INF>, the 
significant emissions rate is 40 tpy. In addition, the source must 
demonstrate through dispersion modeling that construction and operation 
of the source will not cause or contribute to a violation of any NAAQS 
or violate any prevention of significant deterioration increment.
    In addition to the preexisting NSR programs, Washington's 
maintenance plan includes a stepwise process for assessing the 
cumulative impacts of new sources constructed in the area and 
triggering deployment of SO<INF>2</INF> monitors. This process will 
ensure that cumulative impacts remain below the NAAQS should multiple 
facilities move to the nonattainment area. Under the maintenance plan 
verification of continued attainment provisions, Washington, with NWCAA 
as the lead agency for the jurisdiction in coordination with Ecology, 
will evaluate the cumulative impacts of the new source or modifications 
using three sequential ``Action Levels.'' Under Action Level 1, 
Washington will conduct cumulative dispersion modeling using potential 
emissions if two conditions are met: (1) the cumulative potential 
SO<INF>2</INF> emissions in the area are greater than or equal to 250 
tons per year of SO<INF>2</INF> and (2) the proposed new source or 
modification has the potential to emit 40 tons per year of 
SO<INF>2</INF> (the significant emission rate under the major NSR 
program). Washington will use EPA's preferred screening and dispersion 
modeling tools identified in 40 CFR part 51 appendix W (``Appendix W'') 
as normally applicable for any source seeking a construction permit 
under the NSR program. If the results of the modeling under Action 
Level 1 indicate a design concentration of greater than or equal to 90% 
of the 1-hour NAAQS, then Washington will proceed to Action Level 2.
    Under Action Level 2, Washington will conduct refined dispersion 
modeling that uses actual emissions from existing sources and potential 
emissions from the new source or modification. If the results of that 
modeling indicate a design concentration of greater than or equal to 
50% of the 1-hour SO<INF>2</INF> NAAQS, then Washington will proceed to 
Action Level 3.
    Under Action Level 3, Washington will deploy SO<INF>2</INF> ambient 
monitors within 1 year of the initial startup of the new source or 
modification. Any new monitors established for verification of 
continued attainment will be operated as State and Local Air Monitoring 
Stations (SLAMS) as part of Ecology's Primary Quality Assurance 
Organization (PQAO). Ecology will verify that monitor siting complies 
with 40 CFR part 58 appendix E (Probe and Monitoring Path Siting 
Criteria for Ambient Air Quality Monitoring) and will include any new 
site proposals in its annual Ambient Air Monitoring Network Plan. This 
plan is available for public inspection and comment for at least 30 
days before its submission to the EPA by July 1 of each year. Any such 
proposal will be subject to review and approval by the EPA Regional 
Administrator, following the process described in 40 CFR 58.10.
    The State of Washington has the legal authority to enforce and 
implement the maintenance plan for the Whatcom County (partial) 2010 
SO<INF>2</INF> NAA. This includes the authority to conduct the stepwise 
ambient air quality analysis, deploy monitors, and adopt, implement, 
and enforce any subsequent emissions control contingency measures

[[Page 79202]]

determined to be necessary to correct future SO<INF>2</INF> attainment 
problems.\25\
---------------------------------------------------------------------------

    \25\ The EPA last determined that Washington's SIP was 
sufficient to meet the requirements of 110(a)(2)(E)(i) of the CAA on 
February 18, 2021 (86 FR 10022).
---------------------------------------------------------------------------

    Washington's SIP-approved NSR programs coupled with the stepwise 
approach for assessing cumulative impacts is adequate to verify 
continued maintenance of the SO<INF>2</INF> NAAQS. The 250 tpy 
inventory threshold and 40 tpy PTE threshold in Action Level 1 are set 
at emission levels the EPA anticipates would not cause or contribute to 
a violation of the NAAQS. For comparison, the emissions inventory in 
2017 when the area exceeded the NAAQS was 3,987 tpy of emissions from 
the Intalco facility.\26\ Refining the modeling to take into 
consideration actual emissions of existing sources is also sufficiently 
protective, particularly considering that Washington will deploy 
monitors if the design concentration from this modeling is greater than 
or equal to 50% of the SO<INF>2</INF> NAAQS. For these reasons, the EPA 
is proposing to find that Washington's maintenance plan meets the 
Monitoring and ``Verification of Continued Attainment'' requirements.
---------------------------------------------------------------------------

    \26\ See 202_Intalco Sulfur Dioxide Attainment Plan_2202035.pdf, 
at page 45, included in the docket for this action.
---------------------------------------------------------------------------

e. Contingency Measures in the Maintenance Plan
    Section 175A of the CAA requires that a maintenance plan include 
such contingency measures as the EPA deems necessary to assure that the 
state will promptly correct a violation of the NAAQS that occurs after 
redesignation. The maintenance plan should identify the contingency 
measures to be adopted, a schedule and procedure for adoption and 
implementation, and a time limit for action by the state. A state 
should also identify specific indicators to be used to determine when 
the contingency measures need to be implemented. The maintenance plan 
must also include a requirement that a state will implement all 
measures with respect to control of the pollutant that were contained 
in the SIP before redesignation of the area to attainment in accordance 
with section 175A(d).
    The maintenance plan includes an action level to determine when the 
contingency plan process is triggered and a process of developing and 
implementing appropriate control measures. If an SO<INF>2</INF> monitor 
records a consecutive two-year average of the annual 99th percentile of 
1-hour daily maximum SO<INF>2</INF> values exceeding 67.5 ppb (90 
percent of the NAAQS), and such data is certified as accurate, the 
action level is triggered. If the action level is triggered, NWCAA will 
first evaluate whether elevated SO<INF>2</INF> readings are due to 
exceptional events, as defined at 40 CFR 50.1(j), and follow the EPA's 
exceptional events policy. If the action level is triggered and is not 
found to be due to an exceptional event, NWCAA will determine if the 
exceedance was a result of a stationary source's non-compliance with 
existing regulations and/or permit conditions. If so, NWCAA will 
undertake enforcement actions in accordance with current agency policy 
and guidance related to compliance and enforcement. If the high levels 
of SO<INF>2</INF> are not found to be due to a stationary source's non-
compliance, NWCAA will work with the entity or entities believed to be 
responsible for the high levels of SO<INF>2</INF> to evaluate control 
measures necessary to ensure future attainment of the NAAQS. The 
implementation of the control measures will take place no later than 18 
months after NWCAA decides, based on quality-assured ambient data, that 
the action-level response described above was triggered (a consecutive 
two-year average of the annual 99th percentile of 1-hour daily maximum 
SO<INF>2</INF> values exceeding 67.5 ppb).
    Washington must submit to the EPA its analysis demonstrating that 
the proposed control measures are adequate to ensure continued 
maintenance of the 2010 1-hour SO<INF>2</INF> NAAQS in the area or to 
return the area to attainment of the NAAQS. Since the only significant 
source of SO<INF>2</INF> in the nonattainment area has shut down, it is 
not possible to develop specific contingency measures until the cause 
of the elevated concentrations is known. The EPA is proposing to find 
that Washington's maintenance plan meets the ``Contingency Measures'' 
requirement.
    The EPA has concluded that the maintenance plan adequately 
addresses the five basic components of a maintenance plan: The 
attainment emissions inventory, maintenance demonstration, monitoring, 
verification of continued attainment, and a contingency plan. 
Therefore, the EPA proposes to find that the maintenance plan SIP 
revision submitted by Washington for the Whatcom County (partial) 2010 
SO<INF>2</INF> NAA meets the requirements of section 175A of the CAA 
and is approvable.

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

    The EPA is proposing to take the following four separate but 
related actions: (1) determine that the Whatcom County (partial) 
SO<INF>2</INF> nonattainment area is attaining the 2010 1-hour 
SO<INF>2</INF> NAAQS; (2) approve Washington's plan for maintaining the 
2010 1-hour SO<INF>2</INF> NAAQS (maintenance plan), including proposed 
approval of a ``reproducible approach'' to representing the air quality 
of the affected area in the event that the monitors that were sited for 
the Intalco facility shut down; (3) redesignate the Whatcom County 
(partial) SO<INF>2</INF> nonattainment area to attainment for the 2010 
1-hour SO<INF>2</INF> NAAQS; and (4) determine that the Whatcom County 
(partial) SO<INF>2</INF> NAA has clean monitoring data. Section III of 
this document provides a discussion of each of these proposed actions.
    The EPA is also proposing to approve the maintenance plan under the 
2010 NAAQS for the Whatcom County (partial) SO<INF>2</INF> 
nonattainment area into the Washington SIP (under CAA section 175A). 
The maintenance plan demonstrates that the area will continue to 
maintain the 2010 1-hour SO<INF>2</INF> NAAQS and includes a process to 
develop contingency measures to remedy any future violations of the 
2010 1-hour SO<INF>2</INF> NAAQS and procedures for evaluation of 
potential violations.
    Additionally, the EPA is proposing to determine that the Whatcom 
County (partial) SO<INF>2</INF> nonattainment area has met the criteria 
under CAA section 107(d)(3)(E) for redesignation from nonattainment to 
attainment for the 2010 1-hour SO<INF>2</INF> NAAQS. On this basis, the 
EPA is proposing to approve Washington's redesignation request for the 
area. Final approval of Washington's redesignation request would change 
the legal designation of the portion of Whatcom County designated 
nonattainment at 40 CFR 81.348 to attainment for the 2010 1-hour 
SO<INF>2</INF> NAAQS.
    The EPA is also proposing to determine that the Whatcom County 
(partial) SO<INF>2</INF> nonattainment area has attaining monitoring 
data for the 2010 SO<INF>2</INF> primary NAAQS based on the most recent 
complete three-year period (2021-2023) design value period that meets 
the clean data policy. As noted elsewhere, in the event that EPA does 
not finalize the proposed redesignation, the EPA may choose to finalize 
the clean data determination, thereby suspending the attainment 
planning related requirements for the area.

V. Statutory and Executive Order Reviews

    Under the CAA, redesignation of an area to attainment is an action 
that affects the status of a geographical area and does not impose any 
additional regulatory requirements on sources beyond those imposed by 
state law. A redesignation to attainment does not in

[[Page 79203]]

and of itself create any new requirements, but rather results in the 
applicability of requirements contained in the CAA for areas that have 
been redesignated to attainment. In addition, the Administrator is 
required to approve a SIP submission that complies with the provisions 
of the Clean Air 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 Clean Air Act. Accordingly, this action merely proposes to 
approve state law as meeting Federal requirements and does not impose 
additional requirements beyond those imposed by state law. For these 
reasons, this proposed action:
    <bullet> 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 14094 (88 FR 21879, April 11, 2023);
    <bullet> Does not impose an information collection burden under the 
provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
    <bullet> 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.);
    <bullet> 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);
    <bullet> Does not have federalism implications as specified in 
Executive Order 13132 (64 FR 43255, August 10, 1999);
    <bullet> Is not subject to Executive Order 13045 (62 FR 19885, 
April 23, 1997) because it approves a state program;
    <bullet> Is not a significant regulatory action subject to 
Executive Order 13211 (66 FR 28355, May 22, 2001); and
    <bullet> 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 Clean Air Act.
    In addition, this proposed action, pertaining to redesignation of 
the Whatcom County (partial) SO<INF>2</INF> nonattainment area and 
approval of a maintenance plan for the area, would not be 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 would not have Tribal 
implications and would not impose substantial direct costs on tribal 
governments or preempt Tribal law as specified by Executive Order 13175 
(65 FR 67249, November 9, 2000). Consistent with EPA policy, the EPA 
provided a consultation opportunity to Tribes located near the 
nonattainment area, in letters dated July 25, 2024 and July 29, 2024, 
included in the docket for this action.
    Executive Order 12898 (Federal Actions to Address Environmental 
Justice in Minority Populations and Low-Income Populations, 59 FR 7629, 
February 16, 1994) directs Federal agencies to identify and address 
``disproportionately high and adverse human health or environmental 
effects'' of their actions on communities with environmental justice 
(EJ) concerns to the greatest extent practicable and permitted by law. 
The EPA defines EJ as ``the fair treatment and meaningful involvement 
of all people regardless of race, color, national origin, or income 
with respect to the development, implementation, and enforcement of 
environmental laws, regulations, and policies.'' The EPA further 
defines the term fair treatment to mean that ``no group of people 
should bear a disproportionate burden of environmental harms and risks, 
including those resulting from the negative environmental consequences 
of industrial, governmental, and commercial operations or programs and 
policies.''
    The Washington Department of Ecology did evaluate environmental 
justice considerations as part of its SIP submittal; the CAA and 
applicable implementing regulations neither prohibit nor require such 
an evaluation. The EPA did not perform an EJ analysis and did not 
consider EJ in this action. Consideration of EJ is not required as part 
of this action, and there is no information in the record inconsistent 
with the stated goal of Executive Order 12898 of achieving 
environmental justice for communities with EJ concerns.

List of Subjects in 40 CFR Part 52

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

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

    Dated: September 19, 2024.
Casey Sixkiller,
Regional Administrator, Region 10.
[FR Doc. 2024-22171 Filed 9-26-24; 8:45 am]
BILLING CODE 6560-50-P


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