Determination of Attainment by the Attainment Date; Michigan; St. Clair 2010 Sulfur Dioxide Nonattainment Area

ENVIRONMENTAL PROTECTION AGENCY <CFR>40 CFR Part 52</CFR> <DEPDOC>[EPA-R05-OAR-2020-0385; FRL-12224-01-R5]</DEPDOC> <SUBJECT>Determination of Attainment by the Attainment Date; Michigan; St. Clair 2010 Sulfur Dioxide 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> The Environmental Protection Agency (EPA) is proposing to determine that the St. Clair, MI sulfur dioxide (SO <E T="52">2</E> ) nonattainment area attained the 2010 1-hour primary SO <E T="52">2</E> national ambient air quality standard (NAAQS) by the date of September 12, 2021. This determination is based on annual SO <E T="52">2</E> emissions data, modeled data, and certified ambient air quality data from EPA's December 7, 2021, Clean Data Determination for St. Clair, as well as publicly available additional supporting 2020 data. This action, if finalized, will address EPA's obligation under the Clean Air Act (CAA) to determine whether the St. Clair SO <E T="52">2</E> nonattainment area (referred to hereafter as the St. Clair area, or simply the area) attained the 2010 SO <E T="52">2</E> NAAQS by the September 12, 2021, attainment date. </SUM> <EFFDATE> <HD SOURCE="HED">DATES:</HD> Written comments for this proposed rule must be received on or before October 28, 2024. </EFFDATE> <HD SOURCE="HED">ADDRESSES:</HD> Submit your comments, identified by Docket ID No. EPA-R05-OAR-2020-0385 at <E T="03">https://www.regulations.gov</E> or via email to <E T="03">arra.Sarah@epa.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 the docket. EPA may publish any comment received to its public docket. Do not submit to EPA's docket at <E T="03">https://www.regulations.gov</E> any information you consider to be Confidential Business Information (CBI), Proprietary Business Information (PBI), or other information whose disclosure is restricted by statute. Multimedia submissions (audio, video, etc.) must be accompanied by a written comment. The written comment is considered the official comment and should include discussion of all points you wish to make. EPA will generally not consider comments or comment contents located outside of the primary submission ( <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 CBI, PBI, 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> Alexis Bender, Air and Radiation Division (AR-18J), Environmental Protection Agency, Region 5, 77 West Jackson Boulevard, Chicago, Illinois 60604, (312) 886-9497, <E T="03">bender.alexis@epa.gov.</E> The EPA Region 5 office is open from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding Federal holidays and facility closures due to COVID-19. </FURINF> <SUPLINF> <HD SOURCE="HED">SUPPLEMENTARY INFORMATION:</HD> Throughout this document whenever “we,” “us,” or “our” is used, we mean EPA. <HD SOURCE="HD1">I. Background</HD> <HD SOURCE="HD2"> A. The 2010 1-Hour Primary SO <E T="54">2</E> NAAQS </HD> Under section 109 of the CAA, EPA has established primary and secondary NAAQS for certain pervasive air pollutants (referred to as “criteria pollutants”) and conducts periodic reviews of the NAAQS to determine whether they should be revised or whether new NAAQS should be established. On June 22, 2010 (75 FR 35520), EPA published in the <E T="04">Federal Register</E> a strengthened, primary 1-hour SO <E T="52">2</E> NAAQS, establishing a new standard at a level of 75 ppb, based on the 3-year average of the annual 99th percentile of daily maximum 1-hour average concentrations of SO <E T="52">2.</E> This revised SO <E T="52">2</E> NAAQS provided increased protection of public health and provided for revocation of the 1971 primary annual and 24-hour SO <E T="52">2</E> standards for most areas of the country following area designations under the new NAAQS. <HD SOURCE="HD2"> B. Designations and Attainment Dates for the 2010 SO <E T="54">2</E> NAAQS </HD> Following promulgation of a new or revised NAAQS, EPA is required to designate all areas of the country as either “attainment,” “nonattainment,” or “unclassifiable,” pursuant to CAA section 107(d)(1). On July 12, 2016 (81 FR 45039), EPA finalized its second round of initial designations under the 2010 SO <E T="52">2</E> NAAQS. During the second round of designations, the St. Clair area of Michigan was designated as nonattainment for the 2010 SO <E T="52">2</E> NAAQS (40 CFR 81.323) based on modeling of actual emissions for the designated area. CAA section 191(a) directs states containing an area designated nonattainment for the 2010 SO <E T="52">2</E> NAAQS to develop and submit a nonattainment area State Implementation Plan (SIP) to EPA within 18 months of the effective date of an area's designation as nonattainment. The Michigan Department of Environment, Great Lakes, and Energy (EGLE) was required to submit a SIP by March 12, 2018, to bring the St. Clair area into attainment by the attainment date of September 12, 2021. EGLE submitted a request for a Clean Data Determination (CDD) on July 24, 2020. When a nonattainment area is attaining the 2010 SO <E T="52">2</E> NAAQS based on the most recent available data, EPA may issue a CDD suspending planning requirements. EPA issued a CDD for the St. Clair area based on monitoring and modeling data for the 2017-2019 period via a final rule published on December 7, 2021 (86 FR 69173). <HD SOURCE="HD2">C. Requirement To Determine Attainment by the Attainment Date</HD> Section 179(c)(1) of the CAA requires EPA to determine whether a nonattainment area attained a standard by the applicable attainment date based on the area's air quality as of the attainment date. EPA is to issue this determination within six months of the attainment date. Thus, EPA had a mandatory duty under CAA section 179(c) to determine by March 12, 2022 whether the area attained by September 12, 2021. This action proposes to determine the St. Clair area did attain the 2010 SO <E T="52">2</E> NAAQS by the attainment date of September 12, 2021. A determination of whether an area's air quality meets applicable standards is generally based upon the most recent three years of complete, quality-assured data gathered at established State and local air monitoring stations in a nonattainment area and entered into EPA's Air Quality System (AQS) database. Data from ambient air monitors operated by State and local agencies in compliance with EPA monitoring requirements must be submitted to AQS. Monitoring agencies annually certify that these data are accurate to the best of their knowledge. All data are reviewed to determine the area's air quality status in accordance with 40 CFR part 50, appendix T (for SO <E T="52">2</E> ). In general, for SO <E T="52">2</E> , EPA does not rely exclusively on monitoring data to determine whether the NAAQS is met unless it has been demonstrated that the monitors were appropriately sited to record expected maximum ambient concentrations of SO <E T="52">2</E> in an area. As such, monitoring data can be supplemented with other relevant information, including dispersion modeling and emissions inventories, for determining attainment. <HD SOURCE="HD1">II. Proposed Determination of Attainment by the Attainment Date</HD> <HD SOURCE="HD2">A. Area Characterization</HD> The St. Clair area is located within the lower southeastern corner of Michigan northeast of Detroit and shares a border with Ontario, Canada along the St. Clair River. The area is defined by the St. Clair River for the eastern boundary, an extension from the St. Clair River straight west to the intersection of State Highway M-29 and St. Clair River Drive, continuing west on State Highway M-29 to Church Road to Arnold Road to County Line Road for the southern boundary, County Line Road and the Macomb/St. Clair County boundary to Stoddard Road to Wales Ridge Road for the western boundary, and Alpine Road to Fitz Road to Smith Creek Road to Range Road to Huron Avenue, extending straight east from the intersection of Huron Road and River Road to the St. Clair River for the northern boundary. The St. Clair area contains two SO <E T="52">2</E> -emitting facilities that are both coal-fired power plants. Additionally, the area contains two SO <E T="52">2</E> monitors which reside near the facilities. The two monitors have been operating since 2016 and have had no recorded violations of the NAAQS. As these monitors were sited to operate under guidance per the “SO <E T="52">2</E> NAAQS Designations Source-Oriented Monitoring Technical Assistance Document” (SO <E T="52">2</E> Monitoring TAD), EPA believes that these monitors' locations adequately represent the locations of potential maximum SO <E T="52">2</E> impacts from the two power plants. <HD SOURCE="HD2"> B. St. Clair Nonattainment Area's Attainment of the 2010 SO <E T="54">2</E> NAAQS </HD> We propose to determine that the St. Clair nonattainment area attained the 2010 SO <E T="52">2</E> NAAQS by the attainment date of September 12, 2021. EPA previously determined that the St. Clair SO <E T="52">2</E> nonattainment area was attaining the 2010 SO <E T="52">2</E> NAAQS in its December 7, 2021 (86 FR 69173), CDD. EPA issued the CDD based on SO <E T="52">2</E> monitoring and modeling data from EGLE. For this dete ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Preview showing 10k of 20k characters. 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