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

ENVIRONMENTAL PROTECTION AGENCY <CFR>40 CFR Part 52</CFR> <DEPDOC>[EPA-R10-OAR-2024-0371; FRL-12159-01-R10]</DEPDOC> <SUBJECT> Designation of Areas for Air Quality Planning Purposes; Redesignation Request and Associated Maintenance Plan for Whatcom County, WA 2010 SO <E T="0735">2</E> Nonattainment Area </SUBJECT> <HD SOURCE="HED">AGENCY:</HD> Environmental Protection Agency (EPA). <HD SOURCE="HED">ACTION:</HD> Proposed rule. <SUM> <HD SOURCE="HED">SUMMARY:</HD> 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 <E T="52">2</E> ) 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 <E T="52">2</E> nonattainment area (NAA) is attaining the 2010 SO <E T="52">2</E> primary NAAQS; approve Washington's plan for maintaining attainment of the 2010 SO <E T="52">2</E> primary NAAQS in the area; and redesignate the Whatcom County (partial) SO <E T="52">2</E> NAA to attainment for the 2010 1-hour primary SO <E T="52">2</E> NAAQS. </SUM> <EFFDATE> <HD SOURCE="HED">DATES:</HD> Written comments must be received on or before October 28, 2024. </EFFDATE> <HD SOURCE="HED">ADDRESSES:</HD> Submit your comments, identified by Docket ID No. EPA-R10-OAR-2024-0371 at <E T="03">https://www.regulations.gov.</E> For comments submitted at <E T="03">regulations.gov,</E> follow the online instructions for submitting comments. Once submitted, comments cannot be edited or removed from <E T="03">regulations.gov.</E> 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 ( <E T="03">i.e.,</E> on the web, cloud, or other file sharing system). For additional submission methods, please contact the person identified in the <E T="02">FOR FURTHER INFORMATION CONTACT</E> 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 <E T="03">https://www.epa.gov/dockets/commenting-epa-dockets.</E> <FURINF> <HD SOURCE="HED">FOR FURTHER INFORMATION CONTACT:</HD> Jeff Hunt, EPA Region 10, 1200 Sixth Avenue, Suite 155, Seattle, WA 98101, at (206) 553-6357 or h <E T="03">unt.jeff@epa.gov.</E> </FURINF> <SUPLINF> <HD SOURCE="HED">SUPPLEMENTARY INFORMATION:</HD> Throughout this document, the use of “we” and “our” means the EPA. <HD SOURCE="HD1">I. What is the background for the EPA's proposed actions?</HD> On June 22, 2010, the EPA published a new 1-hour primary SO <E T="52">2</E> 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 <E T="52">2</E> monitoring data for specific stationary sources that may cause or contribute to violations of the revised SO <E T="52">2</E> NAAQS and recommended that all areas in the state be designated as unclassifiable. In response to the lack of sufficient SO <E T="52">2</E> 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 <E T="52">2</E> 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 <E T="52">2</E> NAAQS with a 2017-2019 design value of 106 ppb. <SU>1</SU> <FTREF/> 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 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 <E T="52">2</E> 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 <E T="52">2</E> 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 <E T="52">2</E> 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 <E T="52">2</E> Area Designation” included in the docket for this action. <FTNT> <SU>1</SU>  The design value is the metric used for determining compliance with the SO <E T="52">2</E> NAAQS under appendix T of 40 CFR part 50. </FTNT> 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 <E T="52">2</E> wet scrubber. <SU>2</SU> <FTREF/> Subsequently, on March 16, 2023, Alcoa Corporation publicly announced their plans to permanently close the Intalco facility. <SU>3</SU> <FTREF/> 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. <SU>4</SU> <FTREF/> 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 <E T="52">2</E> 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 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Preview showing 10k of 66k characters. Full document text is stored and available for version comparison. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━