# Federal Implementation Plan Addressing Regional Ozone Transport for the 2015 Ozone National Ambient Air Quality Standard > Briefs, arguments, decisions, and more. URL: https://www.frixlaw.com/law-library/documents/fr%3A2022-04551 ## Record - **Collection:** Federal Register - **Document type:** Proposed Rule - **Published:** April 6, 2022 - **Citation:** 87 FR 20036 ## Text ENVIRONMENTAL PROTECTION AGENCY 40 CFR Parts 52, 75, 78 and 97 [EPA-HQ-OAR-2021-0668; FRL 8670-01-OAR] RIN 2060-AV51 Federal Implementation Plan Addressing Regional Ozone Transport for the 2015 Ozone National Ambient Air Quality Standard AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule. SUMMARY: This action proposes Federal Implementation Plan (FIP) requirements to address twenty-six states' obligations to eliminate significant contribution to nonattainment, or interference with maintenance, of the 2015 ozone National Ambient Air Quality Standard (NAAQS) in other states. The U.S. Environmental Protection Agency (EPA) is proposing this action under the “good neighbor” or “interstate transport” provision of the Clean Air Act (CAA or Act). The Agency proposes establishing nitrogen oxides emissions budgets requiring fossil fuel-fired power plants in 25 states to participate in an allowance-based ozone season trading program beginning in 2023. The Agency is also proposing to establish nitrogen oxides emissions limitations applicable to certain other industrial stationary sources in 23 states with an earliest possible compliance date of 2026. These industrial source types are: Reciprocating internal combustion engines in Pipeline Transportation of Natural Gas; kilns in Cement and Cement Product Manufacturing; boilers and furnaces in Iron and Steel Mills and Ferroalloy Manufacturing; furnaces in Glass and Glass Product Manufacturing; and high-emitting equipment and large boilers in Basic Chemical Manufacturing, Petroleum and Coal Products Manufacturing, and Pulp, Paper, and Paperboard Mills. DATES: Comments must be received on or before June 6, 2022. Public Hearing: The EPA will hold a virtual public hearing on April 21, 2022. Please refer to the SUPPLEMENTARY INFORMATION section for additional information on the public hearing. Information Collection Request (ICR): Under the Paperwork Reduction Act (PRA), comments on the information collection provisions are best assured of consideration if the Office of Management and Budget (OMB) receives a copy of your comments on or before May 6, 2022. ADDRESSES: You may send comments, identified by Docket ID No. EPA-HQ-OAR-2021-0668; via the Federal eRulemaking Portal: https://www.regulations.gov/ (our preferred method). Follow the online instructions for submitting comments. Instructions: All submissions received must include the Docket ID No. for this rulemaking. Comments received may be posted without change to https://www.regulations.gov/, including any personal information provided. For detailed instructions on sending comments and additional information on the rulemaking process, see the “Public Participation” heading of the SUPPLEMENTARY INFORMATION section of this document. Out of an abundance of caution for members of the public and our staff, the EPA Docket Center and Reading Room are open to the public by appointment only to reduce the risk of transmitting COVID-19. Our Docket Center staff also continues to provide remote customer service via email, phone, and webform. Hand deliveries and couriers may be received by scheduled appointment only. For further information on EPA Docket Center services and the current status, please visit us online at https://www.epa.gov/dockets. The virtual public hearing will be held on April 21, 2022. The virtual public hearing will convene at 10 a.m. Eastern Time (ET) and will conclude at 7 p.m. ET. The EPA may close a session 15 minutes after the last pre-registered speaker has testified if there are no additional speakers. For information or questions about the public hearing, please contact Ms. Holly DeJong at Dejong.holly@epa.gov. The EPA will announce further details at https://www.epa.gov/csapr/csapr-2015-ozone-naaqs. Refer to the SUPPLEMENTARY INFORMATION section for additional information. FOR FURTHER INFORMATION CONTACT: Ms. Elizabeth Selbst, Air Quality Policy Division, Office of Air Quality Planning and Standards (C539-01), Environmental Protection Agency, 109 TW Alexander Drive, Research Triangle Park, NC 27711; telephone number: (919)-541-3918; email address: Selbst.elizabeth@epa.gov. SUPPLEMENTARY INFORMATION: Preamble Glossary of Terms and Abbreviations The following are abbreviations of terms used in the preamble. 2016v1 2016 Version 1 Emissions Modeling Platform 2016v2 2016 Version 2 Emissions Modeling Platform 4-Step Framework 4-Step Interstate Transport Framework ACS American Community Survey AEO Annual Energy Outlook AQAT Air Quality Assessment Tool AQMTSD Air Quality Modeling Technical Support Document BACT Best Available Control Technology BPT Benefit Per Ton CAA or Act Clean Air Act CAIR Clean Air Interstate Rule CBI Confidential Business Information CCR Coal Combustion Residual CDC Centers for Disease Control and Prevention CEMS Continuous Emissions Monitoring Systems CES Clean Energy Standards CHP Combined Heat and Power CMDB Control Measures Database CMV Commercial Marine Vehicle CoST Control Strategy Tool CPT Cost Per Ton CSAPR Cross-State Air Pollution Rule EGU Electric Generating Unit EIA U.S. Energy Information Agency EISA Energy Independence and Security Act ELG Effluent Limitation Guidelines E.O. Executive Order EPA or the Agency United States Environmental Protection Agency FFS Finding of Failure To Submit FIP Federal Implementation Plan GIS Geographic Information System HDGHG Greenhouse Gas Emissions and Fuel Efficiency Standards for Medium- and Heavy-Duty Engines and Vehicles HEDD High Electricity Demand Days ICI Industrial, Commercial, and Institutional I/M Inspection and Maintenance IPM Integrated Planning Model LNB Low-NO X Burners MJO Multi-Jurisdictional Organization MOVES Motor Vehicle Emission Simulator MSAT2 Mobile Source Air Toxics Rule MWC Municipal Waste Combustor NAAQS National Ambient Air Quality Standards NAICS North American Industry Classification System NEEDS National Electric Energy Data System NEI National Emissions Inventory NESHAP National Emissions Standards for Hazardous Air Pollutants No SISNOSE No Significant Economic Impact on a Substantial Number of Small Entities Non-EGU Non-Electric Generating Unit NO X Nitrogen Oxides NSPS New Source Performance Standard NREL National Renewable Energy Lab NTTAA National Technology Transfer and Advancement Act OFA Over-Fire Air OMB United States Office of Management and Budget OSAT/APCA Ozone Source Apportionment Technology/Anthropogenic Precursor Culpability Analysis OTC Ozone Transport Commission OTR Ozone Transport Region OTSA Oklahoma Tribal Statistical Area PEMS Predictive Emissions Monitoring Systems PM 2.5 Fine Particulate Matter ppb parts per billion ppm parts per million ppmvd parts per million by volume, dry PRA Paperwork Reduction Act RACT Reasonably Available Control Technology RFA Regulatory Flexibility Act RICE Reciprocating Internal Combustion Engines ROP Rate of Progress RPS Renewable Portfolio Standards RRF Relative Response Factor SAFE Safer Affordable Fuel-Efficient Vehicles Rule SAFETEA Safe, Accountable, Flexible, Efficient, Transportation Equity Act SCR Selective Catalytic Reduction SIP State Implementation Plan SMOKE Sparse Matrix Operator Kernel Emissions SNCR Selective Non-Catalytic Reduction SO 2 Sulfur Dioxide tpd ton per day TSD Technical Support Document UMRA Unfunded Mandates Reform Act VMT Vehicle Miles Traveled VOCs Volatile Organic Compounds WRAP Western Regional Air Partnership WRF Weather Research and Forecasting Table of Contents I. Executive Summary A. Purpose of Regulatory Action 1. Emissions Limitations for EGUs Established by the Proposed Rule 2. Emissions Limitations for Non-EGU Stationary Point Sources Established by the Proposed Rule 3. Proposed Error Correction for Previously Approved 2015 Ozone Transport SIP 4. Request for Comment on All Aspects of the Proposal B. Summary of the Major Provisions of the Regulatory Action C. Benefits and Costs II. Public Participation A. Written Comments B. Submitting Confidential Business Information C. Participation in Virtual Public Hearing III. General Information A. Does this action apply to me? B. What action is the Agency taking? C. What is the Agency's legal authority for taking this action? 1. Statutory Authority D. What actions has EPA previously issued to address regional ozone transport? IV. Air Quality Issues Addressed and Overall Approach for the Proposed Rule A. The Interstate Ozone Transport Air Quality Challenge 1. Nature of Ozone and the Ozone NAAQS 2. Ozone Transport 3. Health and Environmental Effects B. Proposed Rule Approach 1. The 4-Step Interstate Transport Framework a. Step 1 Approach b. Step 2 Approach c. Step 3 Approach d. Step 4 Approach 2. FIP Authority for Each State Covered by the Proposed Rule C. Other CAA Authorities for This Action 1. Correction of EPA's Determination Regarding Delaware's SIP Submission and Its Impact on EPA's FIP Authority for Delaware 2. Application of Rule in Indian Country and Necessary or Appropriate Finding a. Indian Country Subject to State Implementation Planning Authority V. Analyzing Downwind Air Quality Problems and Contributions From Upwind States A. Selection of Analytic Years for Evaluating Ozone Transport Contributions to Downwind Air Quality Problems B. Overview of Air Quality Modeling Platform C. Emissions Inventories 1. Foundation Emissions Inventory Data Sets 2. Development of Emissions Inventories for EGUs 3. Development of Emissions Inventories for Non-EGU Point Sources 4. Development of Emissions Inventories for Onroad Mobile Sources 5. Development of Emissions Inventories for Commercial Marine Vessels 6. Development of Emissions Inventories for Other Nonroad Mobile Sources 7. Development of Emissions Inventories for Nonpoint Sources D. Air Quality Modeling To Identify Nonattainment and Maintenance Receptors E. Pollutant Transport From Upwind States 1. Air Quality Modeling To Quantify Upwind State Contributions 2. Application of Contribution Screening Threshold a. States That Contribute at or Above the Screening Threshold F. Treatment of Certain Receptors in California and Implications for Oregon's Good Neighbor Obligations for 2015 Ozone NAAQS VI. Quantifying Upwind-State NO X Emissions Reduction Potential To Reduce Interstate Ozone Transport for the 2015 Ozone NAAQS A. The Multi-Factor Test for Determining Significant Contribution B. Identifying Control Stringency Levels 1. EGU NO X Mitigation Strategies a. Optimizing Existing SCRs b. Installing State-of-the-Art NO X Combustion Controls c. Optimizing Already Operating SNCRs or Turning on Idled Existing SNCRs d. Installing New SNCRs e. Installing New SCRs f. Generation Shifting 2. Non-EGU NO X Mitigation Strategies a. Determining Non-EGU NO X Reduction Potential 3. Other Stationary Sources NO X Mitigation Strategies a. Units Less Than or Equal to 25 MW b. Municipal Solid Waste Units c. Cogeneration Units 4. Mobile Source NO X Mitigation Strategies C. Control Stringencies Represented by Cost Threshold ($ per Ton) and Corresponding Emissions Reductions 1. EGU Emissions Reduction Potential by Cost Threshold 2. Non-EGU Emissions Reduction Potential—Cost Threshold Up to $7,500/Ton D. Assessing Cost, EGU and Non-EGU NO X Reductions, and Air Quality 1. EGU Assessment 2. Non-EGU Assessment a. Request for Comment on Non-EGU Control Strategies and Measures 3. Combined EGU and Non-EGU Assessment 4. Over-Control Analysis VII. Implementation of Emissions Reductions A. NO X Reduction Implementation Schedule 1. 2023-2025: EGU NO X Reductions Beginning in 2023 2. 2026 and Later Years: EGU and Non-EGU EGU NO X Reductions Beginning in 2026 a. EGU Schedule for 2026 and Later Years b. Non-EGU Schedule for 2026 and Later Years B. Regulatory Requirements for EGUs 1. Trading Program Background and Overview of Proposed Revisions a. Current CSAPR Trading Program Design Elements and Identified Concerns b. Enhancements To Maintain Selected Control Stringency Over Time i. Revised Emissions Budget-Setting Process ii. Allowance Bank Recalibration c. Enhancements To Improve Emissions Performance at Individual Units i. Unit-Specific Backstop Daily Emissions Rates ii. Unit-Specific Emissions Limitations Contingent on Assurance Level Exceedances 2. Expansion of Geographic Scope 3. Applicability and Tentative Identification of Newly Affected Units 4. New and Revised State Emissions Budgets a. Methodology for Determining Preset State Emissions Budgets for the 2023 and 2024 Control Periods b. Methodology for Determining Dynamic State Emissions Budgets for Control Periods in 2025 and Beyond c. Proposed and Illustrative State Emissions Budgets 5. Variability Limits and Assurance Levels 6. Annual Recalibration of Allowance Bank 7. Unit-Specific Backstop Daily Emissions Rates 8. Unit-Specific Emissions Limitations Contingent on Assurance Level Exceedances 9. Unit-Level Allowance Allocation and Recordation Procedures a. Set-Asides of Portions of State Emissions Budgets for New Units b. Allocations to Existing Units, Including Units That Cease Operation c. Allocations From Portions of State Emissions Budgets Set Aside for New Units d. Incorrectly Allocated Allowances 10. Other Trading Program Provisions a. Designated Representative Requirements b. Monitoring and Reporting Requirements 11. Transitional Provisions a. Prorating Emissions Budgets, Assurance Levels, and Unit-Level Allowance Allocations in the Event of an Effective Date After May 1, 2023 b. Creation of Additional Group 3 Allowance Bank for 2023 Control Period c. Recall of Group 2 Allowances for Control Periods After 2022 12. Conforming Revisions to Other Regulations C. Regulatory Requirements for Non-EGUs 1. Pipeline Transportation of Natural Gas 2. Cement and Concrete Product Manufacturing 3. Iron and Steel Mills and Ferroalloy Manufacturing 4. Glass and Glass Product Manufacturing 5. Boilers From Basic Chemical Manufacturing, Petroleum and Coal Products Manufacturing, and Pulp, Paper, and Paperboard Mills a. Coal-Fired Industrial Boilers b. Oil-Fired Industrial Boilers c. Gas-Fired Industrial Boilers D. Submitting a SIP 1. SIP Option To Modify Allocations for 2024 Under EGU Trading Program 2. SIP Option To Modify Allocations for 2025 and Beyond Under EGU Trading Program 3. SIP Option To Replace the Federal EGU Trading Program With an Integrated State EGU Trading Program 4. SIP Revisions That Do Not Use the New Trading Program 5. SIP Revision Requirements for Non-EGU Emissions Limits E. Title V Permitting F. Relationship to Other Emissions Trading and Ozone Transport Programs 1. NO X SIP Call 2. Acid Rain Program 3. Other Current Emissions Trading Programs VIII. Environmental Justice Considerations, Implications, and Stakeholder Outreach A. Introduction B. Analytical Considerations C. Outreach and Engagement IX. Costs, Benefits, and Other Impacts of the Proposed Rule X. Summary of Proposed Changes to the Regulatory Text for the Federal Implementation Plans and Trading Programs for EGUs A. Amendments to FIP Provisions in 40 CFR Part 52 B. Amendments to Group 3 Trading Program and Related Regulations C. Transitional Provisions D. Clarifications and Conforming Revisions XI. Statutory and Executive Order Reviews A. Executive Order 12866: Regulatory Planning and Review and Executive Order 13563: Improving Regulation and Regulatory Review B. Paperwork Reduction Act (PRA) C. Regulatory Flexibility Act (RFA) D. Unfunded Mandates Reform Act (UMRA) E. Executive Order 13132: Federalism F. Executive Order 13175: Consultation and Coordination With Indian Tribal Governments G. Executive Order 13045: Protection of Children From Environmental Health Risks and Safety Risks H. Executive Order 13211: Actions Concerning Regulations That Significantly Affect Energy Supply, Distribution or Use I. National Technology Transfer and Advancement Act (NTTAA) J. Executive Order 12898: Federal Actions To Address Environmental Justice in Minority Populations and Low-Income Populations K. Determinations Under CAA Section 307(b)(1) and (d) I. Executive Summary This proposed rule would resolve the interstate transport obligations of 26 states under CAA section 110(a)(2)(D)(i)(I), referred to as the “good neighbor provision” or the “interstate transport provision” of the Act, for the 2015 ozone NAAQS. On October 1, 2015, the EPA revised the primary and secondary 8-hour standards for ozone to 70 parts per billion (ppb). 1 States were required to provide ozone infrastructure State Implementation Plan (SIP) submissions to fulfill interstate transport obligations for the 2015 ozone NAAQS by October 1, 2018. 1 See 80 FR 65291 (October 26, 2015). The EPA proposes to make a finding that interstate transport of ozone precursor emissions from 26 upwind states (Alabama, Arkansas, California, Delaware, Illinois, Indiana, Kentucky, Louisiana, Maryland, Michigan, Minnesota, Mississippi, Missouri, Nevada, New Jersey, New York, Ohio, Oklahoma, Pennsylvania, Tennessee, Texas, Utah, Virginia, West Virginia, Wisconsin, and Wyoming) is significantly contributing to downwind nonattainment or interfering with maintenance of the 2015 ozone NAAQS in other states, based on projected nitrogen oxides (NO X ) emissions in the 2023 ozone season. The EPA is proposing to issue FIP requirements to eliminate interstate transport of ozone precursors from these 26 states that significantly contributes to nonattainment or interferes with maintenance of the NAAQS in other states. The EPA is proposing FIPs for 23 states for which the Agency has not approved an ozone transport SIP that was submitted for the 2015 ozone NAAQS: Alabama, Arkansas, California, Illinois, Indiana, Kentucky, Louisiana, Maryland, Michigan, Minnesota, Mississippi, Missouri, Nevada, New Jersey, New York, Ohio, Oklahoma, Tennessee, Texas, Utah, West Virginia, Wisconsin, and Wyoming. In this proposed rule, the EPA is proposing to issue FIPs for two states—Pennsylvania and Virginia—for which the EPA issued a Finding of Failure to Submit for 2015 ozone transport SIPs with an effective date of January 6, 2020. Under CAA section 301(d)(4), the EPA proposes to extend FIP requirements to apply in Indian country located within the upwind geography of the proposed rule, including Indian reservation lands and other areas of Indian country over which the EPA or a tribe has demonstrated that a tribe has jurisdiction. 2 The EPA is also proposing a FIP for Delaware and an error correction for the Agency's May 1, 2020, approval at 85 FR 25307 of the interstate transport elements for Delaware's October 11, 2018, and December 26, 2019, ozone infrastructure SIP submissions. 2 In general, specific tribal names or reservations are not identified separately in this proposal except as needed. See Section IV.C.2 of this notice for further discussion. In this proposed rule, the EPA proposes to establish new ozone season NO X emissions budgets beginning in 2023 for Electric Generating Unit (EGU) sources. The EPA is also proposing to establish emissions limitations beginning in 2026 for certain other industrial stationary sources (referred to generally as “non-Electric Generating Units” (non-EGUs)). Taken together, these strategies will fully eliminate the covered states' significant contribution to downwind ozone air quality problems in other states. The EPA proposes to implement the necessary emissions reductions as follows. The proposed FIP requirements establish ozone season NO X emissions budgets for EGUs in 25 states (Alabama, Arkansas, Delaware, Illinois, Indiana, Kentucky, Louisiana, Maryland, Michigan, Minnesota, Mississippi, Missouri, Nevada, New Jersey, New York, Ohio, Oklahoma, Pennsylvania, Tennessee, Texas, Utah, Virginia, West Virginia, Wisconsin, and Wyoming) and require EGUs in these states to participate in a revised version of the Cross-State Air Pollution Rule (CSAPR) NO X Ozone Season Group 3 Trading Program that was previously established in the Revised CSAPR Update. 3 The EPA proposes to amend existing FIPs for 12 states currently participating in the CSAPR NO X Ozone Season Group 3 Trading Program (Illinois, Indiana, Kentucky, Louisiana, Maryland, Michigan, New Jersey, New York, Ohio, Pennsylvania, Virginia, and West Virginia) to replace their existing emissions budgets established in the Revised CSAPR Update (with respect to the 2008 ozone NAAQS) with new emissions budgets. For eight states currently covered by the CSAPR NO X Ozone Season Group 2 Trading Program under SIPs or FIPs, the EPA is proposing to issue new FIPs for two states (Alabama and Missouri) and amend existing FIPs for six states (Arkansas, Mississippi, Oklahoma, Tennessee, Texas, and Wisconsin) to transition EGU sources in these states from the Group 2 program to the revised Group 3 trading program, beginning with the 2023 ozone season. EPA proposes to issue new FIPs for five states not currently covered by any CSAPR NO X ozone season trading program: Delaware, Minnesota, Nevada, Utah, and Wyoming. 3 As explained in Section VI.C.1 of this notice, EPA proposes finding that EGU sources within the State of California are sufficiently controlled such that no further emissions reductions are needed from them to eliminate significant contribution to downwind states. Under this proposed rulemaking, emissions reductions in the selected control stringency would be achieved as soon as they are available, some of which are scheduled to occur by the 2023 ozone season and prior to the August 3, 2024, attainment date for areas classified as Moderate nonattainment for the 2015 ozone NAAQS, and the rest of which occur as soon as possible thereafter through the 2026 ozone season, prior to the August 3, 2027, attainment date for areas classified as Serious nonattainment for the 2015 ozone NAAQS. As discussed in Section VII.A.2 of this notice, the EPA proposes to find that the 2026 ozone season is as expeditious as practicable to implement substantial emissions reductions from potential new post-combustion control installations at EGUs as well as from installation of new pollution controls at non-EGUs. These EGU emissions reductions are scheduled to begin in the 2026 ozone season based on the feasibility of control installation for EGUs in 22 states that remain linked to downwind nonattainment and maintenance receptors in that year. These 22 states are: Arkansas, Illinois, Indiana, Kentucky, Louisiana, Maryland, Michigan, Minnesota, Mississippi, Missouri, Nevada, New Jersey, New York, Ohio, Oklahoma, Pennsylvania, Texas, Utah, Virginia, West Virginia, Wisconsin, and Wyoming. The additional emissions reductions required for these states are based primarily on the potential retrofit of additional post-combustion controls for NO X on most coal steam EGUs and a portion of oil/gas steam EGUs that are currently lacking such controls. In this proposed rule, the EPA introduces additional features to the allowance-based trading program approach for EGUs, including dynamic adjustments of the emissions budgets over time and backstop daily emissions rate limits for most coal-fired units, that will help maintain control stringency over time and improve emissions performance at individual units, providing further assurance that existing pollution controls will be operated during the ozone season and that the emission reductions necessary to meet good neighbor requirements will be achieved. The EPA proposes to find that NO X emissions from non-EGU sources are significantly contributing to nonattainment or interfering with maintenance of the 2015 ozone NAAQS and that cost-effective controls for NO X emissions reductions are available in certain industrial source categories that would result in meaningful air quality improvements in downwind receptors. The EPA proposes to require emissions limitations beginning in 2026 for non-EGUs located within 23 states: Arkansas, California, Illinois, Indiana, Kentucky, Louisiana, Maryland, Michigan, Minnesota, Mississippi, Missouri, Nevada, New Jersey, New York, Ohio, Oklahoma, Pennsylvania, Texas, Utah, Virginia, West Virginia, Wisconsin, and Wyoming. The proposed rule establishes NO X emissions limitations during the ozone season for the following unit types for sources in non-EGU industries: Reciprocating internal combustion in Pipeline Transportation of Natural Gas sources; kilns in Cement and Cement Product Manufacturing sources; boilers and furnaces in Iron and Steel Mills and Ferroalloy Manufacturing sources; furnaces in Glass and Glass Product Manufacturing sources; and high-emitting equipment and large boilers in Basic Chemical Manufacturing, Petroleum and Coal Products Manufacturing, and Pulp, Paper, and Paperboard Mills. A. Purpose of the Regulatory Action The purpose of this rulemaking is to protect public health and the environment by reducing interstate transport of certain air pollutants that significantly contribute to nonattainment, or interfere with maintenance, of the 2015 ozone NAAQS in other states. Ground-level ozone has detrimental effects on human health as well as vegetation and ecosystems. Acute and chronic exposure to ozone in humans is associated with premature mortality and a number of morbidity effects, such as asthma exacerbation. Ozone exposure can also negatively impact ecosystems by limiting tree growth, causing foliar injury, and changing ecosystem community composition. Section IV of this proposed rule provides additional evidence of the harmful effects of ozone exposure on human health and the environment. Studies have established that ozone air pollution can be transported over hundreds of miles, with elevated ground-level ozone concentrations occurring in rural and metropolitan areas. 4 5 Assessments of ozone control approaches have concluded that control strategies targeting reduction of NO X emissions are an effective method to reduce regional-scale ozone transport. 6 4 Bergin, M.S. et al. (2007) Regional air quality: Local and interstate impacts of NO X and SO 2 emissions on ozone and fine particulate matter in the eastern United States. Environmental Sci & Tech. 41: 4677-4689. 5 Liao, K. et al. (2013) Impacts of interstate transport of pollutants on high ozone events over the Mid-Atlantic United States. Atmospheric Environment 84, 100-112. 6 See 82 FR 51238, 51248 (November 3, 2017) [citing 76 FR 48208, 48222 (August 8, 2011)] and 63 FR 57381 (October 27, 1998). CAA section 110(a)(2)(D)(i)(I) requires states to prohibit emissions that will contribute significantly to nonattainment or interfere with maintenance in any other state with respect to any primary or secondary NAAQS. 7 States fulfill their primary responsibility to address interstate transport emissions under the good neighbor provision by submitting SIPs containing enforceable emission limitations and other control measures, means, or techniques required to address the interstate transport provision. Within 3 years of the EPA promulgating a new or revised NAAQS, states are required to provide infrastructure SIP submittals, including good neighbor SIPs. See CAA section 110(a)(1) and (2). When states do not submit approvable interstate transport SIPs or fail to submit interstate transport SIPs by the statutory deadline, the CAA requires the EPA to issue FIPs to ensure that states eliminate their significant contribution to downwind air quality problems under the good neighbor provision. See generally CAA section 110(k) and 110(c). As such, in this proposed rule, the EPA is proposing requirements to fully address good neighbor obligations for these states for the 2015 ozone NAAQS under its authority to promulgate FIPs under CAA section 110(c). 7 42 U.S.C. 7410(a)(2)(D)(i)(I). It is appropriate to issue this proposal at this time for at least three reasons. First, this proposal will ensure that necessary emissions reductions to eliminate significant contribution are achieved as expeditiously as practicable. The EPA's anticipated timing will provide for all possible emissions reductions to go into effect beginning in the 2023 ozone season, which is aligned with the next upcoming attainment date of August 3, 2024, for areas classified as Moderate nonattainment under the 2015 ozone standard. Additional emissions reductions that the EPA finds not possible to implement by that attainment date are proposed to take effect as expeditiously as practicable, with the full suite of emissions reductions taking effect by the 2026 ozone season, which is aligned with the August 3, 2027, attainment date for areas classified as Serious nonattainment under the 2015 ozone NAAQS. As explained in sections V.A, VI, and VII.A of this proposed rule, these proposed timeframes for eliminating significant contribution are consistent with the provisions of title I of the CAA. Second, this proposal will provide states with as much information as the EPA can supply at this time to support their ability to submit SIP revisions to achieve the emissions reductions the EPA believes necessary to eliminate significant contribution. Third, for all of the states included in this proposed rule, the EPA's modeling and analysis indicate that additional emissions reductions beyond those which are provided in any state's 2015 ozone transport SIP are necessary to eliminate significant contribution. The EPA anticipates that the states covered in this proposed FIP rulemaking may not have adequate provisions in their SIPs to address their interstate transport obligations for the 2015 ozone NAAQS. As discussed in Section IV.B.2 of this proposed rule, the EPA has, for certain states, made findings that the state failed to submit a complete good neighbor SIP revision for the 2015 ozone NAAQS. For certain other states, the EPA has proposed, but has not finalized, actions disapproving good neighbor SIP revisions. And for other states, the EPA has not yet proposed action on their good neighbor SIP submittals, but these submittals are currently under review, and EPA intends to act on these submittals in the coming months. The EPA will not finalize this proposed FIP action for any state for which it has not taken final action either disapproving that state's good neighbor SIP submittal or finding that the state failed to submit a complete SIP. The EPA conducted air quality modeling for future analytic years to identify (1) the downwind areas that are expected to have trouble attaining or maintaining the 2015 ozone NAAQS in the future and (2) the contribution of ozone transport from upwind states to the downwind air quality problems. Section V of this proposed rule provides a full description of the results of EPA's air quality modeling and relevant analyses for the proposed rulemaking. Based on EPA's air quality analysis, a total of 27 upwind states are linked above the 1 percent of the NAAQS threshold to downwind air quality problems in other states. The EPA had previously approved 2015 ozone transport SIPs submitted by two of these states—Oregon and Delaware—and proposes in this proposed rule to issue an error correction for its prior approval of Delaware's 2015 ozone transport SIP ( see Section IV.C.1 of this notice for additional information on the proposed error correction). The EPA is not proposing any change to its prior approval of Oregon's 2015 ozone transport SIP, a determination which is further described in Section V.F of this proposed rule. In this proposed rule, the EPA is proposing to issue FIP requirements for 26 states, which include emissions reductions for EGU sources within the borders of 25 states (described in Section VII.B of this proposed rule) and include emissions reductions for non-EGU sources within the borders of 23 states (described in Section VII.C in this proposed rule). Based on EPA's assessment of remaining air quality issues and additional emissions control strategies, the EPA further proposes to find that the EGU and non-EGU NO X emissions reductions required in the proposed rule would fully eliminate these states' significant contributions to downwind air quality problems for the 2015 ozone NAAQS. By eliminating significant contribution from these upwind states, this rule, if finalized as proposed, will make substantial and meaningful improvements in air quality by reducing ozone levels at the identified downwind receptors as well as many other areas of the country. 1. Emissions Limitations for EGUs Established by the Proposed Rule In this proposed rule, the EPA proposes to issue FIP requirements that include new NO X ozone season emissions budgets for EGU sources within the borders of the 25 states listed in Table I.A-1, with implementation of these emissions budgets beginning in the 2023 ozone season. The EPA proposes to find that these emissions reductions are necessary to address upwind states' interstate transport obligations for the 2015 ozone NAAQS. Table I.A-1—Proposed List of 25 Covered States for EGU Emissions Reductions for the 2015 8-Hour Ozone NAAQS State Alabama Arkansas Delaware Illinois Indiana Kentucky Louisiana Maryland Michigan Minnesota Mississippi Missouri Nevada New Jersey New York Ohio Oklahoma Pennsylvania Tennessee Texas Utah Virginia West Virginia Wisconsin Wyoming The EPA proposes to expand the CSAPR NO X Ozone Season Group 3 Trading Program beginning in the 2023 ozone season. Specifically, the FIPs would require power plants within the borders of the 25 states listed in Table I.A-1 to participate in a revised version of the CSAPR NO X Ozone Season Group 3 Trading Program created by the Revised CSAPR Update. Affected EGUs within the borders of twelve states currently participating in the Group 3 Trading Program under FIPs or SIPs would remain in the program, with revised provisions beginning in the 2023 ozone season, under this proposed rule: Illinois, Indiana, Kentucky, Louisiana, Maryland, Michigan, New Jersey, New York, Ohio, Pennsylvania, Virginia, and West Virginia. The FIPs would also require affected EGUs within the borders of eight states currently covered by the CSAPR NO X Ozone Season Group 2 Trading Program (the “Group 2 trading program”) under existing FIPs or existing SIPs to transition from the Group 2 program to the revised Group 3 trading program beginning with the 2023 control period: (Alabama, Arkansas, Mississippi, Missouri, Oklahoma, Tennessee, Texas, and Wisconsin). 8 Finally, the EPA is proposing to issue new FIPs for EGUs within the borders of five states not currently covered by any CSAPR trading program for seasonal NO X emissions: Delaware, Minnesota, Nevada, Utah, and Wyoming. If the proposed FIP is finalized, sources in these states would enter the Group 3 trading program in the 2023 control period following the effective date of the final rule. 9 In all cases, if the state submits and the EPA approves a SIP revision that would fully achieve the emissions reductions needed to meet the state's good neighbor obligations with respect to the 2015 ozone NAAQS before a final rule is promulgated in this rulemaking, the proposed FIP requirements summarized above would not be finalized. Refer to Section VII.B of this proposed rule for details on EGU regulatory requirements. 8 Six of these eight states (Arkansas, Mississippi, Oklahoma, Tennessee, Texas, and Wisconsin) currently participate in the federal Group 2 trading program pursuant to the FIPs finalized in the CSAPR Update, so the FIPs proposed in this rulemaking would amend the existing FIPs for these states. The other two states (Alabama and Missouri) have already replaced the FIPs finalized in the CSAPR Update with approved SIP revisions that require their EGUs to participate in state Group 2 trading programs integrated with the federal Group 2 trading program, so the FIPs proposed in this action would constitute new FIPs for these states, and the EPA would cease implementation of the state Group 2 trading programs included in the two states' SIPs. 9 Two states, Kansas and Iowa, will remain in the Group 2 Trading Program. 2. Emissions Limitations for Non-EGU Stationary Point Sources Established by the Proposed Rule In this proposed rule, the EPA proposes to issue FIP requirements that include new NO X emissions limitations for non-Electric Generating Unit (non-EGU) sources in 23 states, with earliest possible compliance dates for these emissions limitations beginning in 2026. The EPA proposes to require emissions reductions from non-EGU sources to address interstate transport obligations for the 2015 ozone NAAQS for the 23 states listed in Table I.A-2. Table I.A-2—Proposed List of 23 Covered States for Non-EGU Emissions Reductions for the 2015 8-Hour Ozone NAAQS State Arkansas California Illinois Indiana Kentucky Louisiana Maryland Michigan Minnesota Mississippi Missouri Nevada New Jersey New York Ohio Oklahoma Pennsylvania Texas Utah Virginia West Virginia Wisconsin Wyoming The EPA is proposing to require emissions limitations for the following unit types in non-EGU industries: Reciprocating internal combustion engines in Pipeline Transportation of Natural Gas sources; kilns in Cement and Cement Product Manufacturing sources; boilers and furnaces in Iron and Steel Mills and Ferroalloy Manufacturing sources; furnaces in Glass and Glass Product Manufacturing sources; and high-emitting equipment and large boilers in Basic Chemical Manufacturing, Petroleum and Coal Products Manufacturing, and Pulp, Paper, and Paperboard Mills. Refer to Table III.A-1 for a list of North American Industry Classification System (NAICS) codes for each entity included for regulation under this proposed rule. 3. Proposed Error Correction for Previously Approved 2015 Ozone Transport SIP The EPA proposes to make an error correction under CAA section 110(k)(6) of its May 1, 2020, approval at 85 FR 25307 of the interstate transport elements for Delaware's October 11, 2018, and December 26, 2019, ozone infrastructure SIP submissions as satisfying the requirements of CAA section 110(a)(2)(D)(i)(I) for the 2015 ozone NAAQS. The EPA proposes to determine that the basis for the prior SIP approval is invalidated by the Agency's more recent technical evaluation of air quality modeling performed in support of the proposed rule, 10 and that Delaware has unresolved interstate transport obligations for the 2015 ozone NAAQS. In this proposed rule, the EPA is also exercising its authority to propose to issue a FIP for Delaware in light of these unresolved interstate transport obligations. 10 See the Air Quality Modeling Technical Support Document (AQM TSD) in the docket for this proposed rule. 4. Request for Comment on All Aspects of the Proposal Throughout this proposed rule, unless noted otherwise, the EPA is requesting comments on all aspects of the proposal to enable the Agency to develop a final rule that, consistent with our responsibilities under section 110 of the CAA, eliminates air pollution that significantly contributes to nonattainment or interference with maintenance of the 2015 ozone NAAQS. This proposed rule adheres closely to the legal and analytical framework that the EPA has applied in the past in implementing the good neighbor provision of the CAA, as well as the ample case law reviewing that framework. At the same time, in this proposal, the EPA is applying lessons learned from the performance of regulatory programs established by previous ozone transport rulemakings, as well as updating the Agency's application of the 4-step interstate transport framework with recent information on the nature of ozone transport and emissions reductions opportunities in order to eliminate significant contribution for the more stringent 2015 ozone NAAQS under the good neighbor provision. The EPA invites comments and information to support its efforts to improve the regulation of interstate ozone transport under the good neighbor provision and to fulfill our mission to protect human health and the environment. The EPA will carefully consider information provided in response to this request and will respond to comments submitted through the regulatory docket in the final rule. B. Summary of the Major Provisions of the Regulatory Action The EPA is applying the 4-step interstate transport framework developed in CSAPR, the CSAPR Update, the Revised CSAPR Update, and other previous ozone transport rules to propose to further limit NO X emissions from EGU sources within the borders of 25 states during the ozone season (May 1 through September 30) and to limit ozone season NO X emissions from non-EGU sources in 23 states to reduce interstate ozone transport under the authority provided in CAA section 110(a)(2)(D)(i)(I). The 4-step interstate transport framework provides a stepwise method for the EPA to propose rule provisions that are required to address the requirements of the good neighbor provision for the 2015 ozone NAAQS: (1) Identifying downwind receptors that are expected to have problems attaining or maintaining the NAAQS; (2) determining which upwind states contribute to these identified problems in amounts sufficient to “link” them to the downwind air quality problems ( i.e., in this proposed rule, a contribution threshold of 1 percent of the NAAQS); (3) for states linked to downwind air quality problems, identifying upwind emissions that significantly contribute to downwind nonattainment or interfere with downwind maintenance of the NAAQS; and (4) for states that are found to have emissions that significantly contribute to nonattainment or interfere with maintenance of the NAAQS in downwind areas, implementing the necessary emissions reductions through enforceable measures. In this proposed rule, the EPA applies the 4-step framework to evaluate upwind states' obligations to reduce interstate transport of ozone precursor emissions for the 2015 ozone NAAQS. The remainder of this section provides a general overview of the EPA's application of the 4-step framework as it applies to major provisions of the proposed rule; additional details regarding EPA's proposed rule approach are found in Section IV of this proposed rule. In order to apply the first step of the 4-step framework to the 2015 ozone NAAQS, the EPA performed air quality modeling to project ozone concentrations at air quality monitoring sites in 2023, 2026, and 2032. 11 The EPA evaluated projected ozone concentrations for the 2023 analytic year at individual monitoring sites and considered current ozone monitoring data at these sites to identify receptors that are anticipated to have problems attaining or maintaining the 2015 ozone NAAQS. This analysis was then repeated using projected ozone concentrations for 2026 and 2032. 11 These 3 analytic years are the last full ozone seasons before, and thus align with, upcoming attainment dates for the 2015 ozone NAAQS: August 3, 2024, for areas classified as Moderate nonattainment, August 3, 2027, for areas classified as Serious nonattainment, and August 3, 2033, for areas classified as Severe. See 83 FR 25776. To apply the second step of the framework, the EPA used air quality modeling to quantify the contributions from upwind states to ozone concentrations in 2023 and 2026 at downwind receptors. 12 Once quantified, EPA then evaluated these contributions relative to a screening threshold of 1 percent of the NAAQS ( i.e., 0.70 ppb). 13 States with contributions that equaled or exceeded 1 percent of the NAAQS were identified as warranting further analysis at Step 3 of the four-step framework to determine if the upwind state significantly contributes to nonattainment or interference with maintenance in a downwind state. States with contributions below 1 percent of the NAAQS were considered not to significantly contribute to nonattainment or interfere with maintenance of the NAAQS in downwind states. Based on EPA's most recent air quality modeling and contribution analysis using 2023 as the analytic year, the EPA proposes to find that the following 27 states have contributions that equal or exceed 1 percent of the 2015 ozone NAAQS, and, thereby, warrant further analysis of significant contribution to nonattainment or interference with maintenance of the NAAQS: Alabama, Arkansas, California, Delaware, Illinois, Indiana, Kentucky, Louisiana, Maryland, Michigan, Minnesota, Mississippi, Missouri, Nevada, New Jersey, New York, Ohio, Oklahoma, Oregon, Pennsylvania, Tennessee, Texas, Utah, Virginia, West Virginia, Wisconsin, and Wyoming. Further evaluation of the locations in California to which Oregon was linked at Step 2 leads the EPA to conclude downwind areas represented by these monitoring sites should not be considered interstate ozone transport receptors. Therefore, the EPA is not proposing any further emissions reductions from the state of Oregon because there is no significant contribution required to be eliminated under the interstate transport provision, as described in Section V.F of this proposed rule. 12 The EPA did not perform contribution modeling for 2032 since contribution data for this year were not needed to identify upwind states to be analyzed in Step 3. 13 See Section V of this proposed rule for explanation of EPA's use of the 1 percent of the NAAQS threshold in the Step 2 analysis. Based on the air quality analysis presented in Section V of this proposed rule, the EPA proposes to find that in the absence of additional emissions reductions in those states the majority of the states that the EPA is proposing to participate in the Ozone Season Group 3 Trading Program will continue to contribute above the 1 percent of the NAAQS threshold to at least one receptor whose nonattainment and maintenance concerns persist through the 2026 ozone season, with the exception of Alabama, Delaware, and Tennessee. As a result, EPA's evaluation of emissions reduction potential at Step 3 for Alabama, Delaware, and Tennessee is limited to emission reductions achievable by the 2023 ozone season. For each of these three states, EPA's analysis does not consider, nor does the EPA propose to require, emissions reductions at either EGUs or non-EGUs that cannot be implemented until the 2026 ozone season. At the third step of the 4-step framework, EPA applied a multi-factor test that incorporates cost, availability of emissions reductions, and air quality impacts at the downwind receptors to determine the amount of ozone precursor emissions from the linked upwind states that “significantly” contribute to downwind nonattainment or maintenance receptors. In this proposed rule, the EPA proposes to apply the multifactor test described in Section VI.A of this proposed rule to both EGU and non-EGU sources. The EPA assessed the potential emissions reductions in 2023 and 2026, as well as in intervening and later years to determine the emissions reductions required to eliminate significant contribution in any future year where downwind areas are projected to have potential problems attaining or maintaining the 2015 ozone NAAQS. For EGU sources, the EPA evaluated the following set of widely-available NO X emissions control technologies: (1) Fully operating existing selective catalytic reduction (SCR) controls, including both optimizing NO X removal by existing operational SCRs and turning on and optimizing existing idled SCRs; (2) installing state-of-the-art NO X combustion controls; (3) fully operating existing selective non-catalytic reduction (SNCR) controls, including both optimizing NO X removal by existing operational SNCRs and turning on and optimizing existing idled SNCRs; (4) installing new SNCRs; (5) installing new SCRs; and (6) generation shifting. For the reasons explained in Section VI of this proposed rule and supported by the EGU NO X Mitigation Strategies Proposed Rule Technical Support Document (TSD) included in the docket for this proposed rule, the EPA determined that for the regional, multi-state scale of this rulemaking, only fully operating and optimizing existing SCRs and existing SNCRs (EGU NO X emissions controls options 1 and 3 in the list earlier) are possible for the 2023 ozone season. The EPA determined that state-of-the-art NO X combustion controls at EGUs (emissions control option 2 in the list above) are available by the beginning of the 2024 ozone season. Based on EPA's assessment of the earliest possible timeframe for installation of new SNCR and SCRs (EGU emissions controls options 4 and 5 in the list), the EPA proposes to require emissions reductions commensurate with these controls by the beginning of the 2026 ozone season. See Section VI.B.1 of this proposed rule for a full description of EPA's analysis of NO X emissions mitigation strategies for EGU sources. The EPA proposes control stringency levels that maximize incremental NO X emissions reduction potential from EGUs and corresponding downwind ozone air quality improvements to the extent feasible in each year analyzed. The EPA believes that the required controls provide cost-effective reductions of NO X emissions that will provide substantial improvements in downwind ozone air quality to address interstate transport obligations for the 2015 ozone NAAQS in a timely manner. These controls represent greater stringency in upwind EGU controls than in EPA's most recent ozone transport rulemakings, such as the CSAPR Update and the Revised CSAPR Update. However, programs to address interstate ozone transport based on the retrofit of post-combustion controls are by no means unprecedented. In prior ozone transport rulemakings such as the NO X SIP Call and the Clean Air Interstate Rule (CAIR), the EPA established EGU budgets premised on the widespread availability of retrofitting EGUs with post-combustion emissions controls such as SCR. 14 While these programs successfully drove many EGUs to retrofit post-combustion controls, other EGUs throughout the present geography of linked upwind states continue to operate without such controls and continue to emit at relatively high rates more than 20 years after similar units reduced these emissions under prior interstate ozone transport rulemakings. 14 See, e.g., 70 FR 25162, 25205-06 (May 12, 2005). Furthermore, the CSAPR Update provided only a partial remedy for eliminating significant contribution for the 2008 ozone NAAQS, as needed to obtain available reductions by the 2017 ozone season. In that rule, the EPA made no determination regarding the appropriateness of more stringent EGU NO X controls that would be required for a full remedy for interstate transport for the 2008 ozone NAAQS. Following the remand of the CSAPR Update in Wisconsin v. EPA, 938 F.3d 303 (D.C. Cir. 2019) ( Wisconsin ), the EPA again declined to require the retrofit of new post-combustion controls on EGUs in the Revised CSAPR Update, but that determination was based on a specific timing consideration: Downwind air quality problems under the 2008 ozone NAAQS were projected to resolve before post-combustion control retrofits could be accomplished on a fleetwide, regional scale. See 86 FR 23054, 23110 (April 30, 2021). In this proposed rulemaking, the EPA is addressing good neighbor obligations for the more stringent 2015 ozone NAAQS, and the Agency observes ongoing and persistent contribution from upwind states to ozone nonattainment and maintenance receptors in other states under that NAAQS. As further discussed in Section VI of this proposed rule, the nature of this contribution warrants a greater degree of control stringency than the EPA determined to be necessary to eliminate significant contribution of ozone transport in prior CSAPR rulemakings. The EPA is therefore returning to EGU NO X control strategies commensurate with those determined to be necessary in the NO X SIP Call and CAIR. Based on the Step 3 analysis described in Section VI of this proposed rule, the EPA is proposing that emissions reductions commensurate with the full operation of all existing post-combustion controls (both SCRs and SNCRs) and state-of-the-art combustion control upgrades constitute the Agency's selected control stringency for EGUs within the borders of 25 states linked to downwind nonattainment or maintenance in 2023 (Alabama, Arkansas, Delaware, Illinois, Indiana, Kentucky, Louisiana, Maryland, Michigan, Minnesota, Mississippi, Missouri, Nevada, New Jersey, New York, Ohio, Oklahoma, Pennsylvania, Tennessee, Texas, Utah, Virginia, West Virginia, Wisconsin, and Wyoming). For 22 of those states that are also linked in 2026 (Arkansas, Illinois, Indiana, Kentucky, Louisiana, Maryland, Michigan, Minnesota, Mississippi, Missouri, Nevada, New Jersey, New York, Ohio, Oklahoma, Pennsylvania, Texas, Utah, Virginia, West Virginia, Wisconsin, and Wyoming), the EPA is determining that the selected EGU control stringency also includes emissions reductions commensurate with the retrofit of SCR at coal steam units of 100 MW or greater capacity (excepting circulating fluidized bed units (CFB)), new SNCR on coal steam units of less than 100 MW capacity and CFBs, and SCR on oil/gas steam units greater than 100 MW that have historically emitted at least 150 tons of NO X per ozone season. To identify appropriate control strategies for non-EGU sources to achieve NO X emissions reductions that would result in meaningful air quality improvements in downwind areas, the EPA developed an analytical framework to evaluate the air quality impacts of potential emissions reductions from non-EGU sources located in the linked upwind states. The EPA incorporated air quality modeling information, annual emissions, and information about potential controls to determine which industries, if subject to further control requirements, would have the greatest impact in providing air quality improvements at the downwind receptors. This evaluation was subject to a marginal cost threshold of up to $7,500 per ton, which the EPA determined based on information available to the Agency about existing control device efficiency and cost information. Additional information on the analytical framework is described in Section VI.B.2 of this proposed rule and is presented in the memorandum titled Screening Assessment of Potential Emissions Reductions, Air Quality Impacts, and Costs from Non-EGU Emissions Units for 2026 (“Non-EGU Screening Assessment memorandum”), which is available in the docket for this proposed rulemaking. Based on the results of this assessment, the EPA identified emissions unit types in seven industries (identified in Section I.A.2 of this proposed rule) that provide opportunities for NO X emissions reductions that result in meaningful impacts on air quality at the downwind receptors. The EPA performed air quality analysis using the Ozone Air Quality Assessment Tool (AQAT) to determine whether the proposed emissions reductions for both EGUs and non-EGUs potentially create an “over-control” scenario whereby (1) the expected ozone improvements would be greater than necessary to resolve the downwind ozone pollution problem ( i.e., beyond what is necessary to resolve all nonattainment and maintenance problems to which an upwind state is linked) or (2) the expected ozone improvements would reduce the upwind state's ozone contributions below the screening threshold ( i.e., 1 percent of the NAAQS or 0.70 ppb). The EPA's over-control analysis, discussed in Section VI.D.4 of this proposed rule, shows that the proposed control stringencies for EGU and non-EGU sources do not over-control upwind states' emissions either with respect to the downwind air quality problems to which they are linked or with respect to the 1 percent of the NAAQS contribution threshold, such that over-control would trigger re-evaluation at Step 3 for any linked upwind state. Based on the multi-factor test applied to both EGU and non-EGU sources and our subsequent assessment of over-control, the EPA finds that the selected EGU and non-EGU control stringencies constitute the elimination of significant contribution and interference with maintenance, without over-controlling emissions, from the 26 upwind states subject to EGU and non-EGU emissions reductions requirements under the proposed rule. In order to eliminate significant contribution and interference with maintenance through the fourth step of the 4-step framework, as described in Section VII of this proposed rule, the EPA is establishing emissions budgets for EGUs within the borders of 25 states that reflect the remaining allowable emissions after the emissions reductions associated with the selected control stringency have been achieved. For the same reason, the EPA is establishing non-EGU emissions limits in 23 states that result in the elimination of significant contribution from non-EGU sources in these states. For additional details about the test and the over-control analysis, see the document titled, “Ozone Transport Policy Analysis Proposed Rule TSD” included in the docket for this rulemaking. In this fourth step of the 4-step framework, the EPA proposes to include enforceable measures in the promulgated FIPs to achieve the required emissions reductions in each of the 26 states. Specifically, the FIPs would require covered power plants within the borders of the 25 states listed in Table I.A-1 to participate in the CSAPR NO X Ozone Season Group 3 Trading Program created by the Revised CSAPR Update. Affected EGUs within the borders of twelve states currently participating in the Group 3 Trading Program would remain in the program, with revised provisions beginning in the 2023 ozone season, under this proposed rule: Illinois, Indiana, Kentucky, Louisiana, Maryland, Michigan, New Jersey, New York, Ohio, Pennsylvania, Virginia, and West Virginia. Affected EGUs within the borders of eight states currently covered by the CSAPR NO X Ozone Season Group 2 Trading Program (the “Group 2 trading program”)—Alabama, Arkansas, Mississippi, Missouri, Oklahoma, Tennessee, Texas, and Wisconsin—would transition from the Group 2 program to the revised Group 3 trading program beginning with the 2023 control period, 15 and affected EGUs within the borders of five states not currently covered by any CSAPR trading program for seasonal NO X emissions—Delaware, Minnesota, Nevada, Utah, and Wyoming—would enter the Group 3 trading program in the 2023 control period following the effective date of the final rule. In addition, the EPA proposes to revise other aspects of the Group 3 trading program to help maintain control stringency over time and improve emissions performance at individual units, offering a necessary measure of assurance that existing pollution controls will be operated during the ozone season, as described in Section VII of this proposed rule. This proposal does not revise the budget stringency and geography of the existing CSAPR NO X Ozone Season Group 1 trading program. Aside from the eight states moving from the Group 2 trading program to the Group 3 trading program under the proposed rule, this proposal otherwise leaves unchanged the budget stringency of the existing CSAPR NO X Ozone Season Group 2 trading program. 15 The EPA would deem participation in the Group 3 trading program by the EGUs in these eight states as also addressing the respective states' good neighbor obligations with respect to the 2008 ozone NAAQS (for all eight states), the 1997 ozone NAAQS (for all the states except Texas), and the 1979 ozone NAAQS (for Alabama, Missouri, and Tennessee) to the same extent that those obligations are currently being addressed by participation of the states' EGUs in the Group 2 trading program. The EPA is proposing preset ozone season NO X emissions budgets for the 2023 and 2024 ozone seasons, as explained in Section VII.B of this proposed rule and as shown in Table I.B-1. Table I.B-1—Proposed and Illustrative CSAPR NO X Ozone Season Group 3 State Emissions Budgets for 2023 Through 2026 Control Periods * State Proposed emissions budgets for 2023 control period (tons) Proposed emissions budgets for 2024 control period (tons) Illustrative emissions budgets for 2025 control period (tons) Illustrative emissions budgets for 2026 control period (tons) Alabama 6,364 6,306 6,306 6,306 Arkansas 8,889 8,889 8,889 3,923 Delaware 384 434 434 434 Illinois 7,364 7,463 7,463 6,115 Indiana 11,151 9,391 8,714 7,791 Kentucky 11,640 11,640 11,134 7,573 Louisiana 9,312 9,312 9,179 3,752 Maryland 1,187 1,187 1,187 1,189 Michigan 10,718 10,718 10,759 6,114 Minnesota 3,921 3,921 3,910 2,536 Mississippi 5,024 4,400 4,400 1,914 Missouri 11,857 11,857 10,456 7,246 Nevada 2,280 2,372 2,372 1,211 New Jersey 799 799 799 799 New York 3,763 3,763 3,763 3,238 Ohio 8,369 8,369 8,369 8,586 Oklahoma 10,265 9,573 9,393 4,275 Pennsylvania 8,855 8,855 8,855 6,819 Tennessee 4,234 4,234 4,008 4,008 Texas 38,284 38,284 36,619 21,946 Utah 14,981 15,146 15,146 2,620 Virginia 3,090 2,814 2,948 2,567 West Virginia 12,478 12,478 12,478 10,597 Wisconsin 5,963 5,057 4,198 3,473 Wyoming 9,125 8,573 8,573 4,490 * Further information on the state-level emissions budget calculations pertaining to Table I.B-1 is provided in Section VII.B.4 of this proposed rule as well as the Ozone Transport Policy Analysis Proposed Rule TSD. Further information on the proposed approach for allocating a portion of Utah's emissions budget for each control period to the existing EGU in the Uintah and Ouray Reservation within Utah's borders is provided in Section VII.B.9 of this proposed rule. Beyond preset emissions budgets for the 2023 and 2024 control periods, the EPA also proposes to extend the Group 3 trading program budget-setting methodology used in the Revised CSAPR Update so as to routinely set emissions budgets for each future control period (beginning in 2025) in the year before that control period, with each emissions budget reflecting the latest available information on the composition and utilization of the EGU fleet at the time that emissions budget is determined ( see Table VII.B.4.c-2 for illustrative examples of dynamic budget calculations that the EPA will publish in advance of each ozone season, effective for the 2025 control period and beyond). The stringency of the dynamic emissions budgets would simply reflect the stringency of the emissions control strategies selected in the rulemaking more consistently over time and ensure that the annual updates would eliminate emissions determined to be unlawful under the good neighbor provision. See Section VII.B of this proposed rule for additional discussion of EPA's proposed method for adjusting emissions budgets to ensure elimination of significant contribution from EGU sources in the linked upwind states. As an enhancement to the structure of the trading program as originally promulgated in the Revised CSAPR Update, the EPA is also proposing to establish backstop daily emissions rates for coal steam units greater than or equal to 100 MW in covered states. Units emitting in excess of these daily rates would be subject to increased allowance surrender requirements under the trading program. The backstop daily emissions rates would work in tandem with the ozone season emissions budgets to offer downwind stakeholders a necessary measure of assurance that they will be protected on a daily basis during the ozone season by continuous operation of installed pollution controls. The EPA's experience with the CSAPR trading programs has revealed instances where EGUs have reduced their SCRs' performance on a given day, or across the entire ozone seasons in some cases, including high ozone days. 16 In addition to maintaining a mass-based seasonal requirement, the EPA proposes to require controls while maintaining as much compliance flexibility as possible through a unit-level emission rate designed to ensure that controls operate continuously and that required reductions occur on the highest ozone days. These trading program improvements also promote consistent emissions control performance across the power sector, which protects communities living in downwind ozone nonattainment areas from exceedances of the NAAQS that might otherwise occur. 16 See 86 FR 23090. The EPA highlighted the Miami Fort Unit 7 (possessing a SCR) more than tripled its ozone-season NO X emission rate between 2017 and 2019. The EPA proposes to include enforceable emissions standards that will apply during the ozone season (annually from May to September) for seven non-EGU industries in the promulgated FIPs to achieve the required emissions reductions in 23 states with remaining interstate transport obligations for the 2015 ozone NAAQS in 2026: Arkansas, California, Illinois, Indiana, Kentucky, Louisiana, Maryland, Michigan, Minnesota, Mississippi, Missouri, Nevada, New Jersey, New York, Ohio, Oklahoma, Pennsylvania, Texas, Utah, Virginia, West Virginia, Wisconsin, and Wyoming. These requirements would apply to all existing emissions units and to any future emissions units constructed in the covered states after promulgation of the final rule. Thus, the emissions limits for non-EGU sources and associated compliance requirements would apply in all 23 states listed in this paragraph, even if certain of these states do not currently have existing emissions units within a particular industry. Based on our evaluation of the time required to install controls at the types of non-EGU sources covered by this proposed rule, the EPA has identified the 2026 ozone season as the earliest compliance date possible for non-EGU emissions reductions. The EPA is therefore proposing to include non-EGU emissions reductions beginning in 2026. For sources located in the 23 states listed in the previous paragraph, The EPA proposes to require the emissions limits listed in Table I.B-2 for reciprocating internal combustion engines in Pipeline Transportation of Natural Gas; the emissions limits listed in Table I.B-3 for kilns in Cement and Cement Product Manufacturing; the emissions limits listed in Table I.B-4 for boilers and furnaces in Iron and Steel Mills and Ferroalloy Manufacturing; the emissions limits listed in Table I.B-5 for furnaces in Glass and Glass Product Manufacturing; and the emissions limits listed in Table I.B-6 for high-emitting equipment and large boilers in Basic Chemical Manufacturing, Petroleum and Coal Products Manufacturing, and Pulp, Paper, and Paperboard Mills. 17 Based on source cap equation at 30 TAC § 117.3123(b); January 14, 2009 (74 FR 1927), Docket ID No. EPA-R06-OAR-2007-1147, also see https://wayback.archive-it.org/414/20210527223433/https://www.tceq.texas.gov/assets/public/legal/rules/rules/pdflib/117e.pdf. Table I.B-2—Summary of Proposed NO X Emissions Limits for Pipeline Transportation of Natural Gas Engine type and fuel Proposed NO X emissions limit Natural Gas Fired Four Stroke Rich Burn 1.0 g/hp-hr. Natural Gas Fired Four Stroke Lean Burn 1.5 g/hp-hr. Natural Gas Fired Two Stroke Lean Burn 3.0 g/hp-hr. Table I.B-3—Summary of Proposed NO X Emissions Limits for Kiln Types in Cement and Concrete Product Manufacturing Kiln type Proposed NO X emissions limit (lb/ton of clinker) Long Wet 4.0 Long Dry 3.0 Preheater 3.8 Precalciner 2.3 Preheater/Precalciner 2.8 The EPA is also proposing a source cap limit expressed in ton per day (tpd) of NO X for each individual cement plant according to the following equation. 17 EP06AP22.000 Where: CAP2015 Ozone Transport = total allowable NO X emissions from all cement kilns located at one cement plant, in tons per day, on a 30-operating day rolling average basis; KD = 1.7 pounds NO X per ton of clinker for dry preheater-precalciner or precalciner kilns; KW = 3.4 pounds NO X per ton of clinker for long wet kilns; ND = the average annual production in tons of clinker plus one standard deviation for the three most recent calendar years from all dry preheater-precalciner or precalciner kilns located at one cement plant; and NW = the average annual production in tons of clinker plus one standard deviation for the 3 most recent calendar years from all long wet kilns located at one cement plant. An affected cement plant will need to comply with both the source cap limit and the specific NO X emissions limits assigned to its individual kiln type(s). Refer to Section VII.C.2 of this proposed rule for additional information concerning the application of the source cap limit to this industry source group. Table I.B-4—Summary of Proposed NO X Emissions Limits for Iron and Steel and Ferroalloy Emissions Units Emissions unit Proposed NO X emissions standard or requirement (lbs/hour or lb/mmBtu) Blast Furnace 0.03 lb/mmBtu. Basic Oxygen Furnace 0.07 lb/ton. Electric Arc Furnace 0.15 lb/ton steel. Ladle/tundish Preheaters 0.06 lb/mmBtu. Reheat furnace 0.05 lb/mmBtu. Annealing Furnace 0.06 lb/mmBtu. Vacuum Degasser 0.03 lb/mmBtu. Ladle Metallurgy Furnace 0.1 lb/ton. Taconite production kilns Work practice standard to install low NO X technology/burners, test and set. Coke ovens (charging and coking) 0.6 lb/ton of coal charged. Coke ovens (pushing) 0.015 lb/ton of coal pushed. Boilers—Coal 0.20 lb/mmBtu. Boilers—Residual oil 0.20 lb/mmBtu. Boilers—Distillate oil 0.12 lb/mmBtu. Boilers—Natural gas 0.08 lb/mmBtu. Table IV.B-5—Summary of Proposed NO X Emissions Limits for Furnace Unit Types in Glass and Glass Product Manufacturing Furnace type Proposed NO X emissions limit (lb/ton of glass produced) Container Glass Manufacturing Furnace 4.0 Pressed/Blown Glass Manufacturing Furnace or Fiberglass Manufacturing Furnace 4.0 Flat Glass Manufacturing Furnace 9.2 Table I.B-6—Summary of Proposed NO X Emissions Limits for High-Emitting Equipment and Large Boilers in Basic Chemical Manufacturing, Petroleum and Coal Products Manufacturing, and Pulp, Paper, and Paperboard Mills Unit type Emissions limit (lbs NO X /mmBtu) Coal 0.20 Residual oil 0.20 Distillate oil 0.12 Natural gas 0.08 Refer to Section VII.C of this proposed rule for applicability criteria, compliance assurance requirements, and the EPA's rationale in proposing these emissions limits for each of the non-EGU industries covered by the proposed rule. In addition, the EPA requests comment on several topics regarding the implementation of emissions limits for non-EGU sources that are proposed in this rulemaking, including controls on emissions units and control installation timing. See Section VI.D.2.a of this proposed rule for a list of detailed questions on which the Agency is soliciting public comment. The remainder of this preamble is organized as follows: Section III of this proposed rule outlines general applicability criteria for the proposed rule and describes the EPA's legal authority for this proposed rule, the relationship of the proposed rule to previous interstate ozone transport rulemakings, and the incremental costs and benefits of the proposed rule; Section IV of this proposed rule describes the human health and environmental challenges posed by interstate transport contributions to ozone air quality problems, as well as EPA's overall approach for addressing interstate transport for the 2015 ozone NAAQS in this proposed rule; Section V of this proposed rule describes the Agency's analyses of air quality data to inform this proposed rulemaking, including descriptions of the air quality modeling platform and emissions inventories used in the proposed rule, as well as EPA's methods for identifying downwind air quality problems and upwind states' ozone transport contributions to downwind states; Section VI of this proposed rule describes EPA's approach to quantifying upwind states' obligations in the form of EGU NO X control stringencies and non-EGU emissions limits; Section VII of this proposed rule describes key elements of the implementation schedule for EGU and non-EGU emissions reductions requirements, including details regarding the revised aspects of the CSAPR NO X Group 3 trading program and compliance deadlines, as well as regulatory requirements and compliance deadlines for non-EGU sources; Section VIII of this proposed rule discusses the environmental justice considerations of the proposed rule; Section IX of this proposed rule describes the expected costs, benefits, and other impacts of this proposed rule; Section X of this proposed rule provides a summary of proposed changes to the existing regulatory text; and Section XI of this proposed rule discusses the statutory and executive orders affecting this proposed rulemaking. C. Costs and Benefits A summary of the key results of the cost-benefit analysis that was prepared for this proposed rule is presented in Table I.C-1. Table I.C-1 presents estimates of the present values (PV) and equivalent annualized values (EAV), calculated using discount rates of 3 and 7 percent as directed by OMB's Circular A-4, of the health benefits, compliance costs, and net benefits of the proposed rule, in 2016 dollars, discounted to 2022. The estimated monetized net benefits are the estimated monetized benefits minus the estimated monetized costs of the proposed rule. These results present an incomplete overview of the effects of the proposal, because important categories of benefits—including benefits from reducing climate pollution, other types of air pollutants, and water pollution—were not monetized and are therefore not reflected in the cost-benefit tables. We anticipate that taking non-monetized effects into account would show the proposal to be more net beneficial than this table reflects. Table I.C-1—Estimated Monetized Benefits, Compliance Costs, and Net Benefits of the Proposed Rule, 2023 Through 2042 [Millions 2016$, discounted to 2022] a 3% Discount rate 7% Discount rate Present Value: Benefits b 250,000 150,000 Compliance Costs c 22,000 14,000 Net Benefits 220,000 130,000 Equivalent Annualized Value: Benefits 17,000 14,000 Compliance Costs 1,500 1,300 Net Benefits 15,000 12,000 a Rows may not appear to add correctly due to rounding. b The annualized present value of costs and benefits are calculated over a 20-year period from 2023 to 2042. Monetized benefits include those related to public health associated with reductions in PM 2.5 and ozone concentrations. The health benefits are associated with several point estimates and are presented at real discount rates of 3 and 7 percent. Several categories of benefits remain unmonetized and are thus not reflected in the table. Non-monetized benefits include important climate benefits from reductions in CO 2 emissions. The U.S. District Court for the Western District of Louisiana has issued an injunction concerning the monetization of the benefits of greenhouse gas emission reductions by EPA and other defendants. See Louisiana v. Biden , No. 21-cv-01074-JDC-KK (W.D. La. Feb. 11, 2022). Therefore, such values are not presented in the benefit-cost analysis of this proposal conducted pursuant to E.O. 12866. Please see Chapter 5, Section 5.2 of the RIA for more discussion. In addition, there are important unquantified water quality benefits and benefits associated with reductions in other air pollutants. c The costs presented in this table are consistent with the costs presented in Chapter 4 of the RIA. To estimate these annualized costs, EPA uses a conventional and widely accepted approach that applies a capital recovery factor (CRF) multiplier to capital investments and adds that to the annual incremental operating expenses. Costs were calculated using a 3.76% real discount rate consistent with the rate used in IPM's objective function for cost-minimization. As shown in Table I.C-1, the PV of the benefits, associated with reductions in PM 2.5 and ozone concentrations, of this proposed rule, discounted at a 3-percent discount rate, is estimated to be about $250,000 million, with an EAV of about $17,000 million. At a 7-percent discount rate, the PV of the benefits is estimated to be $150,000 million, with an EAV of about $14,000 million. The PV of the compliance costs, discounted at a 3-percent rate, is estimated to be about $22,000 million, with an EAV of about $1,500 million. At a 7-percent discount rate, the PV of the compliance costs is estimated to be about $14,000 million, with an EAV of about $1,300 million. II. Public Participation A. Written Comments Submit your comments, identified by Docket ID No. EPA-HQ-OAR-2021-0668 at https://www.regulations.gov (our preferred method), or the other methods identified in the ADDRESSES section. Once submitted, comments cannot be edited or removed from the docket. The EPA may publish any comment received to its public docket. Do not submit to EPA's docket at https://www.regulations.gov 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, 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. Due to public health concerns related to COVID-19, the EPA Docket Center and Reading Room are open to the public by appointment only. Our Docket Center staff also continues to provide remote customer service via email, phone, and webform. Hand deliveries or couriers will be received by scheduled appointment only. For further information and updates on EPA Docket Center services, please visit us online at https://www.epa.gov/dockets. The EPA continues to carefully and continuously monitor information from the Centers for Disease Control and Prevention (CDC), local area health departments, and our Federal partners so that we can respond rapidly as conditions change regarding COVID-19. B. Submitting Confidential Business Information Do not submit information containing CBI to the EPA through https://www.regulations.gov. Clearly mark the part or all of the information that you claim to be CBI. For CBI information on any digital storage media that you mail to the EPA, mark the outside of the digital storage media as CBI and then identify electronically within the digital storage media the specific information that is claimed as CBI. In addition to one complete version of the comments that includes information claimed as CBI, you must submit a copy of the comments that does not contain the information claimed as CBI directly to the public docket through the procedures outlined in Instructions earlier. If you submit any digital storage media that does not contain CBI, mark the outside of the digital storage media clearly that it does not contain CBI. Information not marked as CBI will be included in the public docket and the EPA's electronic public docket without prior notice. Information marked as CBI will not be disclosed except in accordance with procedures set forth in 40 Code of Federal Regulations (CFR) part 2. Our preferred method to receive CBI is for it to be transmitted to electronically using email attachments, File Transfer Protocol (FTP), or other online file sharing services ( e.g., Dropbox, OneDrive, Google Drive). Electronic submissions must be transmitted directly to the OAQPS CBI Office using the email address, oaqpscbi@epa.gov, and should include clear CBI markings as described above. If assistance is needed with submitting large electronic files that exceed the file size limit for email attachments, and if you do not have your own file sharing service, please email oaqpscbi@epa.gov to request a file transfer link. If sending CBI information through the postal service, please send it to the following address: OAQPS Document Control Officer (C404-02), OAQPS, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, Attention Docket ID No. EPA-HQ-OAR-2021-0668. The mailed CBI material should be double wrapped and clearly marked. Any CBI markings should not show through the outer envelope. C. Participation in Virtual Public Hearing Please note that because of current CDC recommendations, as well as state and local orders for social distancing to limit the spread of COVID-19, the EPA cannot hold in-person public meetings at this time. The EPA will begin pre-registering speakers for the hearing no later than 1 business day after publication of this document in the Federal Register . To register to speak at the virtual hearing, please use the online registration form available at https://www.epa.gov/csapr/csapr-2015-ozone-naaqs. The last day to pre-register to speak at the hearing will be April 21, 2022. The EPA will post a general agenda for the hearing that will list pre-registered speakers in approximate order at: https://www.epa.gov/csapr/csapr-2015-ozone-naaqs. The virtual public hearing will be held on via teleconference on April 21, 2022. The virtual public hearing will convene at 10:00 a.m. Eastern Time (ET) and will conclude at 7:00 p.m. ET. The EPA may close a session 15 minutes after the last pre-registered speaker has testified if there are no additional speakers. For information or questions about the public hearing, please contact Ms. Holly DeJong at Dejong.holly@epa.gov. The EPA will announce further details at https://www.epa.gov/csapr/csapr-2015-ozone-naaqs. The EPA will make every effort to follow the schedule as closely as possible on the day of the hearing; however, please plan for the hearings to run either ahead of schedule or behind schedule. Each commenter will have 5 minutes to provide oral testimony. The EPA encourages commenters to provide the EPA with a copy of their oral testimony electronically (via email) by emailing it to Dejong.holly@epa.gov. The EPA also recommends submitting the text of your oral comments as written comments to the rulemaking docket. The EPA may ask clarifying questions during the oral presentations, but will not respond to the presentations at that time. Written statements and supporting information submitted during the comment period will be considered with the same weight as oral comments and supporting information presented at the public hearing. Please note that any updates made to any aspect of the hearing will be posted online at https://www.epa.gov/csapr/csapr-2015-ozone-naaqs. While the EPA expects the hearing to go forward as set forth above, please monitor our website or contact Ms. Holly DeJong at Dejong.holly@epa.gov to determine if there are any updates. The EPA does not intend to publish a document in the Federal Register announcing updates. If you require the services of a translator or special accommodations such as audio description, please pre-register for the hearing and describe your needs by April 18, 2022. EPA may not be able to arrange accommodations without advanced notice. III. General Information A. Does this action apply to me? This proposed rule affects EGU and non-EGU sources, and regulates the groups identified in Table III.A-1. Table III.A-1—Regulated Groups Industry group NAICS Fossil fuel-fired electric power generation 221112 Pipeline Transportation of Natural Gas 4862 Cement and Concrete Product Manufacturing 3273 Iron and Steel Mills and Ferroalloy Manufacturing 3311 Glass and Glass Product Manufacturing 3272 Basic Chemical Manufacturing 3251 Petroleum and Coal Products Manufacturing 3241 Pulp, Paper, and Paperboard Mills 3221 This table is not intended to be exhaustive, but rather provides a guide for readers regarding entities likely to be regulated by this proposed rule. This table lists the types of entities that the EPA is now aware could potentially be regulated by this proposed rule. Other types of entities not listed in the table could also be regulated. For example, the EPA is requesting comment in Section VI.B.3 of this proposed rule on potential control strategies for sources outside of the categories listed in the Table III.A.1, such as municipal waste combustors (MWCs). To determine whether your EGU entity is proposed to be regulated by this proposed rule, you should carefully examine the applicability criteria found in 40 CFR 97.1004, which the EPA is not proposing to alter in this proposed rule. If you have questions regarding the applicability of this proposed rule to a particular entity, consult the person listed in the FOR FURTHER INFORMATION CONTACT section. B. What action is the Agency taking? The EPA evaluated whether interstate ozone transport emissions from upwind states are significantly contributing to nonattainment, or interfering with maintenance, of the 2015 ozone NAAQS in any downwind state using the same 4-step interstate transport framework that was developed in previous ozone transport rulemakings. The EPA is proposing to find that emissions reductions are required from EGU and non-EGU sources in a total of 26 upwind states to eliminate significant contribution to downwind air quality problems for the 2015 ozone standard under the interstate transport provision of the CAA. The EPA will ensure that these NO X emissions reductions are achieved by issuing proposed FIP requirements for 26 states: Alabama, Arkansas, California, Delaware, Illinois, Indiana, Kentucky, Louisiana, Maryland, Michigan, Minnesota, Mississippi, Missouri, Nevada, New Jersey, New York, Ohio, Oklahoma, Pennsylvania, Tennessee, Texas, Utah, Virginia, West Virginia, Wisconsin, and Wyoming. The EPA is proposing to revise the existing CSAPR Group 3 Trading Program to include additional states beginning in the 2023 ozone season. EGUs in five states not currently covered by any CSAPR trading program for seasonal NO X emissions—Delaware, Minnesota, Nevada, Utah, and Wyoming—would be added to the CSAPR Group 3 Trading Program under this proposed rule. EGUs in twelve states currently participating in the Group 3 Trading Program would remain in the program under this proposed rule: Illinois, Indiana, Kentucky, Louisiana, Maryland, Michigan, New Jersey, New York, Ohio, Pennsylvania, Virginia, and West Virginia. EGUs in eight states (Alabama, Arkansas, Mississippi, Missouri, Oklahoma, Tennessee, Texas, and Wisconsin) will transition from the CSAPR Group 2 Trading Program to the CSAPR Group 3 Trading Program under this proposed rule beginning in the 2023 ozone season. The EPA proposes to establish control stringency levels reflecting installation of state-of-the-art combustion controls on certain covered EGU sources in emissions budgets beginning in the 2024 ozone season. The EPA proposes to establish control stringency levels reflecting installation of new SCR or SNCR controls on certain covered EGU sources in emissions budgets beginning in the 2026 ozone season. As a complement to the ozone season emissions budgets, the EPA is also proposing to establish backstop daily emissions rates of 0.14 lb/mmBtu for coal-fired steam units greater than or equal to 100 MW in covered states. The backstop emissions rates will first apply in 2024 for coal-fired steam sources with existing SCRs, and in 2027 for those currently without SCRs. In this proposed rule, the EPA is proposing to require emissions limitations for non-EGU sources in 23 states: Arkansas, California, Illinois, Indiana, Kentucky, Louisiana, Maryland, Michigan, Minnesota, Mississippi, Missouri, Nevada, New Jersey, New York, Ohio, Oklahoma, Pennsylvania, Texas, Utah, Virginia, West Virginia, Wisconsin, and Wyoming. In these states, EPA is proposing to require emissions limitations for the following unit types in non-EGU industries: Furnaces in Glass and Glass Product Manufacturing; boilers and furnaces in Iron and Steel Mills and Ferroalloy Manufacturing; kilns in Cement and Cement Product Manufacturing; reciprocating internal combustion engines in Pipeline Transportation of Natural Gas; and high-emitting equipment and large boilers in Basic Chemical Manufacturing, Petroleum and Coal Products Manufacturing, and Pulp, Paper, and Paperboard Mill. See Table III.A-1 for a list of NAICS codes for each entity included for regulation under this proposed rule. The proposed rule would reduce the transport of ozone precursor emissions to downwind areas, which is protective of human health and the environment because acute and chronic exposure to ozone are both associated with negative health impacts. Ozone exposure is also associated with negative effects on ecosystems. Additional information on the human health and environmental benefits from the air quality issues addressed by this proposed rule are included in Section IV of this proposed rule. C. What is the Agency's legal authority for taking this action? 1. Statutory Authority The statutory authority for this proposed rule is provided by the CAA as amended (42 U.S.C. 7401 et seq. ). Specifically, sections 110 and 301 of the CAA provide the primary statutory underpinnings for this proposed rule. The most relevant portions of CAA section 110 are subsections 110(a)(1), 110(a)(2) (including 110(a)(2)(D)(i)(I)), 110(c)(1), and 110(k)(6)). CAA section 110(a)(1) provides that states must make SIP submissions “within 3 years (or such shorter period as the Administrator may prescribe) after the promulgation of a national primary ambient air quality standard (or any revision thereof),” and that these SIP submissions are to provide for the “implementation, maintenance, and enforcement” of such NAAQS. 18 The statute directly imposes on states the duty to make these SIP submissions, and the requirement to make the submissions is not conditioned upon the EPA taking any action other than promulgating a new or revised NAAQS. 19 18 42 U.S.C. 7410(a)(1). 19 See EPA v. EME Homer City Generation, L.P., 572 U.S. 489, 509-10 (2014). The EPA has historically referred to SIP submissions made for the purpose of satisfying the applicable requirements of CAA sections 110(a)(1) and 110(a)(2) as “infrastructure SIP” or “iSIP” submissions. CAA section 110(a)(1) addresses the timing and general requirements for iSIP submissions, and CAA section 110(a)(2) provides more details concerning the required content of these submissions. 20 It includes a list of specific elements that “[e]ach such plan” must address. 21 20 42 U.S.C. 7410(a)(2). 21 EPA's general approach to infrastructure SIP submissions is explained in greater detail in individual notices acting or proposing to act on state infrastructure SIP submissions and in guidance. See, e.g., Memorandum from Stephen D. Page on Guidance on Infrastructure State Implementation Plan (SIP) Elements under Clean Air Act Sections 110(a)(1) and 110(a)(2) (September 13, 2013). CAA section 110(c)(1) requires the Administrator to promulgate a FIP at any time within two years after the Administrator: (1) Finds that a state has failed to make a required SIP submission; (2) finds a SIP submission to be incomplete pursuant to CAA section 110(k)(1)(C); or (3) disapproves a SIP submission. This obligation applies unless the state corrects the deficiency through a SIP revision that the Administrator approves before the FIP is promulgated. 22 22 42 U.S.C. 7410(c)(1). CAA section 110(a)(2)(D)(i)(I), also known as the “good neighbor” provision, provides the primary basis for this proposed rule. 23 It requires that each state SIP include provisions sufficient to “prohibit[ ], consistent with the provisions of this subchapter, any source or other type of emissions activity within the State from emitting any air pollutant in amounts which will—(I) contribute significantly to nonattainment in, or interfere with maintenance by, any other State with respect to any [NAAQS].” 24 The EPA often refers to the emissions reduction requirements under this provision as “good neighbor obligations” and submissions addressing these requirements as “good neighbor SIPs.” 23 42 U.S.C. 7410(a)(2)(D)(i)(I). 24 Id. Once EPA promulgates a NAAQS, the EPA must designate areas as being in “attainment” or “nonattainment” of the NAAQS, or “unclassifiable.” CAA section 107(d). 25 For ozone, nonattainment is further split into five classifications based on the severity of the violation—Marginal, Moderate, Serious, Severe, or Extreme. Higher classifications provide states with progressively more time to attain while imposing progressively more stringent control requirements. See CAA sections 181, 182. 26 In general, states with nonattainment areas classified as Moderate or higher must submit plans to EPA to bring these areas into attainment according to the statutory schedule. CAA section 182. 27 If an area fails to attain the NAAQS by the attainment date associated with its classification, it is “bumped up” to the next classification. CAA section 181(b). 28 25 42 U.S.C. 7407(d). 26 42 U.S.C. 7511, 7511a. 27 42 U.S.C. 7511a. 28 42 U.S.C. 7511(b). Section 301(a)(1) of the CAA gives the Administrator the general authority to prescribe such regulations as are necessary to carry out functions under the Act. 29 Pursuant to this section, EPA has authority to clarify the applicability of CAA requirements and undertake other rulemaking action as necessary to implement CAA requirements. CAA section 301 affords the Agency any additional authority that may be needed in order to make certain other changes to its regulations under 40 CFR parts 52, 75, 78, and 97, in order to effectuate the purposes of the Act. Such changes are discussed in Section X of this proposed rule. 29 42 U.S.C. 7601(a)(1). Section 110(k)(6) of the CAA gives the Administrator authority, without any further submission from a state, to revise certain prior actions, including actions to approve SIPs, upon determining that those actions were in error. 30 The EPA proposes to make an error correction under CAA section 110(k)(6) with respect to its prior approval of the 2015 ozone transport SIP submission from the State of Delaware. This is further discussed in Section IV.C.1 of the proposed rule. 30 42 U.S.C. 7410(k)(6). Tribes are not required to submit state implementation plans. However, as explained in EPA's regulations outlining Tribal Clean Air Act authority, the EPA is authorized to promulgate FIPs for Indian country as necessary or appropriate to protect air quality if a tribe does not submit, and obtain EPA approval of, an implementation plan. See 40 CFR 49.11(a); see also CAA section 301(d)(4). 31 In this proposed rule, the EPA proposes an “appropriate or necessary” finding under CAA section 301(d) and proposes tribal FIP(s) as necessary to implement the relevant requirements. This is further discussed in Section IV.C.2 of the proposed rule. 31 42 U.S.C. 7601(d)(4). D. What actions has EPA previously issued to address regional ozone transport? The EPA has issued several major rules interpreting and clarifying the requirements of CAA section 110(a)(2)(D)(i)(I) with respect to the regional transport of ozone. These rules, and the associated court decisions addressing these rules, summarized here, provide important direction regarding the requirements of CAA section 110(a)(2)(D)(i)(I). The “NO X SIP Call,” promulgated in 1998, addressed the good neighbor provision for the 1979 1-hour ozone NAAQS. 32 The rule required 22 states and the District of Columbia to amend their SIPs to reduce NO X emissions that contribute to ozone nonattainment in downwind states. The EPA set ozone season NO X budgets for each state, and the states were given the option to participate in a regional allowance trading program, known as the NO X Budget Trading Program. 33 The D.C. Circuit largely upheld the NO X SIP Call in Michigan v. EPA, 213 F.3d 663 (D.C. Cir. 2000), cert. denied, 532 U.S. 904 (2001). 32 Finding of Significant Contribution and Rulemaking for Certain States in the Ozone Transport Assessment Group Region for Purposes of Reducing Regional Transport of Ozone, 63 FR 57356 (Oct. 27, 1998). As originally promulgated, the NO X SIP Call also addressed good neighbor obligations under the 1997 8-hour ozone NAAQS, but EPA subsequently stayed and later rescinded the rule's provisions with respect to that standard. See 84 FR 8422 (March 8, 2019). 33 “Allowance Trading,” sometimes referred to as “cap and trade,” is an approach to reducing pollution that has been used successfully to protect human health and the environment. The design elements of EPA's most recent trading programs are discussed in Section VII.B.1.a of this proposed rule. EPA's next rule addressing the good neighbor provision, the Clean Air Interstate Rule (CAIR), was promulgated in 2005 and addressed both the 1997 fine particulate matter (PM 2.5 ) NAAQS and 1997 ozone NAAQS. 34 CAIR required SIP revisions in 28 states and the District of Columbia to reduce emissions of sulfur dioxide (SO 2 ) or NO X —important precursors of regionally transported PM 2.5 (SO 2 and annual NO X ) and ozone (summer-time NO X ). As in the NO X SIP Call, states were given the option to participate in regional trading programs to achieve the reductions. When the EPA promulgated the final CAIR in 2005, the EPA also issued findings that states nationwide had failed to submit SIPs to address the requirements of CAA section 110(a)(2)(D)(i) with respect to the 1997 PM 2.5 and 1997 ozone NAAQS. 35 On March 15, 2006, the EPA promulgated FIPs to implement the emissions reductions required by CAIR. 36 CAIR was remanded to EPA by the D.C. Circuit in North Carolina v. EPA, 531 F.3d 896 (D.C. Cir. 2008), modified on reh'g, 550 F.3d 1176. For more information on the legal issues underlying CAIR and the D.C. Circuit's holding in North Carolina, refer to the preamble of the CSAPR rule. 37 34 Rule To Reduce Interstate Transport of Fine Particulate Matter and Ozone (Clean Air Interstate Rule); Revisions to Acid Rain Program; Revisions to the NO X SIP Call, 70 FR 25162 (May 12, 2005). 35 70 FR 21147 (April 25, 2005). 36 71 FR 25328 (April 28, 2006). 37 Federal Implementation Plans: Interstate Transport of Fine Particulate Matter and Ozone and Correction of SIP Approvals, 76 FR 48208, 48217 (August 8, 2011). In 2011, the EPA promulgated CSAPR to address the issues raised by the remand of CAIR. CSAPR addressed the two NAAQS at issue in CAIR and additionally addressed the good neighbor provision for the 2006 PM 2.5 NAAQS. 38 CSAPR required 28 states to reduce SO 2 emissions, annual NO X emissions, or ozone season NO X emissions that significantly contribute to other states' nonattainment or interfere with other states' abilities to maintain these air quality standards. 39 To align implementation with the applicable attainment deadlines, the EPA promulgated FIPs for each of the 28 states covered by CSAPR. The FIPs require EGUs in the covered states to participate in regional trading programs to achieve the necessary emissions reductions. Each state can submit a good neighbor SIP at any time that, if approved by EPA, would replace the CSAPR FIP for that state. 38 76 FR 48208. 39 CSAPR was revised by several rulemakings after its initial promulgation in order to revise certain states' budgets and to promulgate FIPs for five additional states addressing the good neighbor obligation for the 1997 ozone NAAQS. See 76 FR 80760 (December 27, 2011); 77 FR 10324 (February 21, 2012); 77 FR 34830 (June 12, 2012). CSAPR was the subject of an adverse decision by the D.C. Circuit in August 2012. 40 However, this decision was reversed in April 2014 by the Supreme Court, which largely upheld the rule, including EPA's approach to addressing interstate transport in CSAPR. EPA v. EME Homer City Generation, L.P., 572 U.S. 489 (2014) ( EME Homer City I ). The rule was remanded to the D.C. Circuit to consider claims not addressed by the Supreme Court. Id. In July 2015 the D.C. Circuit generally affirmed EPA's interpretation of various statutory provisions and EPA's technical decisions. EME Homer City Generation, L.P. v. EPA, 795 F.3d 118 (2015) ( EME Homer City II ). However, the court remanded the rule without vacatur for reconsideration of EPA's emissions budgets for certain states, which the court found may have over-controlled those states' emissions with respect to the downwind air quality problems to which the states were linked. Id. at 129-30, 138. For more information on the legal issues associated with CSAPR and the Supreme Court's and D.C. Circuit's decisions in the EME Homer City litigation, refer to the preamble of the CSAPR Update. 41 40 On August 21, 2012, the D.C. Circuit issued a decision in EME Homer City Generation, L.P. v. EPA, 696 F.3d 7 (D.C. Cir. 2012), vacating CSAPR. The EPA sought review with the D.C. Circuit en banc and the D.C. Circuit declined to consider EPA's appeal en banc. EME Homer City Generation, L.P. v. EPA, No. 11-1302 (D.C. Cir. January 24, 2013), ECF No. 1417012 (denying EPA's motion for rehearing en banc). 41 Cross-State Air Pollution Rule Update for the 2008 Ozone NAAQS, 81 FR 74504, 74511 (October 26, 2016). In 2016, the EPA promulgated the CSAPR Update to address interstate transport of ozone pollution with respect to the 2008 ozone NAAQS. 42 The final rule updated the CSAPR ozone season NO X emissions budgets for 22 states to achieve cost-effective and immediately feasible NO X emissions reductions from EGUs within those states. 43 The EPA aligned the analysis and implementation of the CSAPR Update with the 2017 ozone season in order to assist downwind states with timely attainment of the 2008 ozone NAAQS. 44 The CSAPR Update implemented the budgets through FIPs requiring sources to participate in a revised CSAPR NO X ozone season trading program beginning with the 2017 ozone season. As under CSAPR, each state could submit a good neighbor SIP at any time that, if approved by the EPA, would replace the CSAPR Update FIP for that state. The final CSAPR Update also addressed the remand by the D.C. Circuit of certain states' CSAPR phase 2 ozone season NO X emissions budgets in EME Homer City II. 42 81 FR 74504. 43 One state, Kansas, was made newly subject to ozone season NO X requirements by the CSAPR Update. All other CSAPR Update states were already subject to ozone season NO X requirements under CSAPR. 44 81 FR 74516. EPA's final 2008 Ozone NAAQS SIP Requirements Rule, 80 FR 12264, 12268 (March 6, 2015), revised the attainment deadline for ozone nonattainment areas designated as Moderate to July 20, 2018. See 40 CFR 51.1103. In order to demonstrate attainment by this deadline, states were required to rely on design values calculated using ozone season data from 2015 through 2017, since the July 20, 2018, deadline did not afford enough time for measured data of the full 2018 ozone season. In December 2018, the EPA promulgated the CSAPR “Close-Out,” which determined that no further enforceable reductions in emissions of NO X were required with respect to the 2008 ozone NAAQS for 20 of the 22 eastern states covered by the CSAPR Update, and reflected that determination in revisions to the existing state-specific sections of the CSAPR Update regulations for those states. 45 45 Determination Regarding Good Neighbor Obligations for the 2008 Ozone National Ambient Air Quality Standard, 83 FR 65878, 65882 (Dec. 21, 2018). After promulgating the CSAPR Update and before promulgating the CSAPR Close-Out, the EPA approved a SIP from Kentucky resolving the Commonwealth's good neighbor obligations for the 2008 ozone NAAQS. 83 FR 33730 (July 17, 2018). In the Revised CSAPR Update, the EPA made an error correction under CAA section 110(k)(6) to convert this approval to a disapproval, because the Kentucky approval relied on the same analysis which the D.C. Circuit determined to be unlawful in the CSAPR Close-Out. The CSAPR Update and the CSAPR Close-Out were both subject to legal challenges in the D.C. Circuit. Wisconsin v. EPA, 938 F.3d 303 (D.C. Cir. 2019) ( Wisconsin ); New York v. EPA, 781 Fed. App'x 4 (D.C. Cir. 2019) ( New York ). In September 2019, the D.C. Circuit upheld the CSAPR Update in virtually all respects but remanded the rule because it was partial in nature and did not fully eliminate upwind states' significant contribution to nonattainment or interference with maintenance of the 2008 ozone NAAQS by “the relevant downwind attainment deadlines” in the CAA. Wisconsin, 938 F.3d at 313-15. In October 2019, the D.C. Circuit vacated the CSAPR Close-Out on the same grounds that it remanded the CSAPR Update in Wisconsin, specifically that the Close-Out rule did not address good neighbor obligations by “the next applicable attainment date” of downwind states. New York, 781 Fed. App'x at 7. 46 46 Subsequently, the D.C. Circuit made clear in a decision reviewing EPA's denial of a petition under CAA section 126 that the holding in Wisconsin regarding alignment with downwind area's attainment schedules applies with equal force to the Marginal area attainment date established under CAA section 181(a). See Maryland v. EPA, 958 F.3d 1185, 1203-04 (D.C. Cir. 2020). In response to the Wisconsin remand of the CSAPR Update and the New York vacatur of the CSAPR Close-Out, the EPA promulgated the Revised CSAPR Update on April 30, 2021. 47 The Revised CSAPR Update found that the CSAPR Update was a full remedy for nine of the covered states. For the 12 remaining states, the EPA found that their projected 2021 ozone season NO X emissions significantly contribute to downwind states' nonattainment or maintenance problems. The EPA issued new or amended FIPs for these 12 states and required implementation of revised emissions budgets for EGUs beginning with the 2021 ozone season. Based on EPA's assessment of remaining air quality issues and additional emissions control strategies for EGUs and emissions sources in other industry sectors (non-EGUs), the EPA determined that the NO X emissions reductions achieved by the Revised CSAPR Update fully eliminated these states' significant contributions to downwind air quality problems for the 2008 ozone NAAQS. As under the CSAPR and the CSAPR Update, each state can submit a good neighbor SIP at any time that, if approved by EPA, would replace the Revised CSAPR Update FIP for that state. 48 47 Revised Cross-State Air Pollution Rule Update for the 2008 Ozone NAAQS, 86 FR 23054 (April 30, 2021). 48 The Revised CSAPR Update is currently subject to a petition for judicial review pending in the D.C. Circuit Court of Appeals, Midwest Ozone Group v. EPA, No. 21-1146 (D.C. Cir. June 25, 2021). IV. Air Quality Issues Addressed and Overall Approach for the Proposed Rule A. The Interstate Ozone Transport Air Quality Challenge 1. Nature of Ozone and the Ozone NAAQS Ground-level ozone is not emitted directly into the air but is created by chemical reactions between NO X and volatile organic compounds (VOCs) in the presence of sunlight. Emissions from electric utilities and industrial facilities, motor vehicles, gasoline vapors, and chemical solvents are some of the major sources of NO X and VOCs. Because ground-level ozone formation increases with temperature and sunlight, ozone levels are generally higher during the summer months. Increased temperature also increases emissions of volatile man-made and biogenic organics and can also indirectly increase NO X emissions ( e.g., increased electricity generation for air conditioning). On October 1, 2015, the EPA strengthened the primary and secondary ozone standards to 70 ppb as an 8-hour level. 49 Specifically, the standards require that the 3-year average of the fourth highest 24-hour maximum 8-hour average ozone concentration may not exceed 70 ppb as a truncated value ( i.e., digits to right of decimal removed). 50 In general, areas that exceed the ozone standard are designated as nonattainment areas, pursuant to the designations process under CAA section 107, and are subject to heightened planning requirements depending on the degree of severity of their nonattainment classification, see CAA sections 181, 182. 49 80 FR 65291. 50 40 CFR part 50, Appendix P to part 50 In the process of setting the 2015 ozone NAAQS, the EPA noted that the conditions conducive to the formation of ozone ( i.e., seasonally-dependent factors such as ambient temperature, strength of solar insolation, and length of day) differ by location, and that the Agency believes it is important that ozone monitors operate during all periods when there is a reasonable possibility of ambient levels approaching the level of the NAAQS. At that time, the EPA stated that ambient ozone concentrations in many areas could approach or exceed the level of the NAAQS, more frequently and during more months of the year compared with the historical ozone season monitoring lengths. Consequently, the EPA extended the ozone monitoring season for many locations. See 80 FR 65416 for more details. Furthermore, the EPA stated that in addition to being affected by changing emissions, future ozone concentrations may also be affected by climate change. Modeling studies in the EPA's Interim Assessment (U.S. EPA, 2009a) that are cited in support of the 2009 Endangerment Finding under CAA section 202(a) (74 FR 66496, Dec. 15, 2009) as well as a recent assessment of potential climate change impacts (Fann et al., 2015) project that climate change may lead to future increases in summer ozone concentrations across the contiguous U.S. 51 (80 FR 65300). The increase in ozone results from changes in local weather conditions, including temperature and atmospheric circulation patterns, as well as changes in ozone precursor emissions that are influenced by meteorology (Nolte et al., 2018). While the projected impact may not be uniform, climate change has the potential to increase average summertime ozone relative to a future without climate change. 52 53 54 Climate change has the potential to offset some of the improvements in ozone air quality, and therefore some of the improvements in public health, that are expected from reductions in emissions of ozone precursors (80 FR 65300). 51 These modeling studies are based on coupled global climate and regional air quality models and are designed to assess the sensitivity of U.S. air quality to climate change. A wide range of future climate scenarios and future years have been modeled and there can be variations in the expected response in U.S. O 3 by scenario and across models and years, within the overall signal of higher summer O 3 concentrations in a warmer climate. 52 Fann NL, Nolte CG, Sarofim MC, Martinich J, Nassikas NJ. Associations Between Simulated Future Changes in Climate, Air Quality, and Human Health. JAMA Netw Open. 2021;4(1):e2032064. doi: 10.1001/jamanetworkopen.2020.32064. 53 Christopher G Nolte, Tanya L Spero, Jared H Bowden, Marcus C Sarofim, Jeremy Martinich, Megan S Mallard. Regional temperature-ozone relationships across the U.S. under multiple climate and emissions scenarios. J Air Waste Manag Assoc. 2021 Oct;71(10):1251-1264. doi: 10.1080/10962247.2021.1970048. 54 Nolte, C.G., P.D. Dolwick, N. Fann, L.W. Horowitz, V. Naik, R.W. Pinder, T.L. Spero, D.A. Winner, and L.H. Ziska, 2018: Air Quality. In Impacts, Risks, and Adaptation in the United States: Fourth National Climate Assessment, Volume II [Reidmiller, D.R., C.W. Avery, D.R. Easterling, K.E. Kunkel, K.L.M. Lewis, T.K. Maycock, and B.C. Stewart (eds.)]. U.S. Global Change Research Program, Washington, DC, USA, pp. 512-538. doi: 10.7930/NCA4.2018.CH13. 2. Ozone Transport Studies have established that ozone formation, atmospheric residence, and transport occur on a regional scale ( i.e., thousands of kilometers) over much of the U.S. 55 While substantial progress has been made in reducing ozone in many areas, the interstate transport of ozone precursor emissions remains an important contributor to peak ozone concentrations and high-ozone days during the summer ozone season. 55 Bergin, M.S. et al. (2007) Regional air quality: Local and interstate impacts of NO X and SO 2 emissions on ozone and fine particulate matter in the eastern United States. Environmental Sci & Tech. 41: 4677-4689. The EPA has previously concluded in the NO X SIP Call, CAIR, CSAPR, the CSAPR Update, and the Revised CSAPR Update that a regional NO X control strategy would be effective in reducing regional-scale transport of ozone precursor emissions. NO X emissions can be transported downwind as NO X or as ozone after transformation in the atmosphere. In any given location, ozone pollution levels are impacted by a combination of background ozone concentration, local emissions, and emissions from upwind sources resulting from ozone transport. Downwind states' ability to meet health-based air quality standards such as the NAAQS is challenged by the transport of ozone pollution across state borders. For example, ozone assessments conducted for the October 2015 Regulatory Impact Analysis of the Final Revisions to the National Ambient Air Quality Standards for Ground-Level Ozone continue to show the importance of NO X emissions for ozone transport. This analysis is included in the docket for this proposal. Further, studies have found that EGU NO X emissions reductions can be effective in reducing individual 8-hour peak ozone concentrations and in reducing 8-hour peak ozone concentrations averaged across the ozone season. For example, a study that evaluates the effectiveness on ozone concentrations of EGU NO X reductions achieved under the NO X Budget Trading Program ( i.e., the NO X SIP Call) shows that regulating NO X emissions in that program was highly effective in reducing ozone concentrations during the ozone season. 56 56 Butler, et al., “Response of Ozone and Nitrate to Stationary Source Reductions in the Eastern USA”. Atmospheric Environment, 2011. Previous regional ozone transport efforts, including the NO X SIP Call, CAIR, CSAPR, the CSAPR Update, and the Revised CSAPR Update, required ozone season NO X reductions from EGU sources to address interstate transport of ozone. Together with NO X , EPA has also identified VOCs as a precursor in forming ground-level ozone. Ozone formation chemistry can be “NO X -limited,” where ozone production is primarily determined by the amount of NO X emissions or “VOC-limited,” where ozone production is primarily determined by the amount of VOC emissions. 57 The EPA and others have long regarded NO X to be the more significant ozone precursor in the context of interstate ozone transport. 58 57 “Ozone Air Pollution.” Introduction to Atmospheric Chemistry, by DANIEL J. JACOB, Princeton University Press, PRINCETON, NEW JERSEY, 1999, pp. 231-244. 58 81 FR 74514. The EPA has determined that the regulation of VOCs as an ozone precursor is not necessary to eliminate significant contribution of ozone transport to downwind areas in this proposed rule. As described in Section VI.A of this proposed rule, the EPA examined the results of the contribution modeling performed for this rule to identify the portion of the ozone contribution attributable to anthropogenic NO X emissions versus VOC emissions from each linked upwind state to each downwind receptor. Our analysis of the ozone contribution from upwind states subject to regulation under this proposed rule demonstrates that the vast majority of the downwind air quality areas are NO X -limited, rather than VOC-limited. Therefore, the proposed rule's strategy for reducing regional-scale transport of ozone targets NO X emissions from stationary sources to achieve the most effective reductions of ozone transport over the geography of the affected downwind areas. Commenters on prior ozone transport rules have asserted that VOC emissions harm underserved and overburdened communities experiencing disproportionate environmental health burdens and facing other environmental injustices. The EPA acknowledges that VOCs can contain toxic chemicals that are detrimental to public health. The EPA conducted a demographic analysis as part of the regulatory impact analysis for the 2015 revisions to the primary and secondary ozone NAAQS. This analysis, which is included in the docket for this proposed rulemaking, found greater representation of minority populations in areas with poor air quality relative to the revised ozone standard than in the U.S. as a whole. The EPA concluded that populations in these areas would be expected to benefit from implementation of future air pollution control actions from state and local air agencies in implementing the strengthened standard. This proposed rule is an example of air pollution control actions implemented by the federal government in support of the more stringent 2015 ozone NAAQS, and populations living in downwind ozone nonattainment areas are expected to benefit from improved air quality that will result from reducing ozone transport. Further discussion of the environmental justice impacts of this proposed rule is located in Section VIII of this proposed rule and in the accompanying regulatory impact analysis, titled “Regulatory Impact Analysis for the Proposed Federal Implementation Plan Addressing Regional Ozone Transport for the 2015 Ozone National Ambient Air Quality Standard” [EPA-452/D-22-001], which is available in the docket for this rulemaking. The Agency regulates exposure to toxic pollutant concentrations and ambient exposure to criteria pollutants other than ozone through other sections of the Act, such as the regulation of hazardous air pollutants under CAA section 112 or the process for revising and implementing the NAAQS under CAA sections 107-110. The purpose of the proposed rulemaking is to protect public health and the environment by eliminating significant contribution from 26 states to nonattainment or maintenance of the 2015 ozone NAAQS in order to meet the requirements of the CAA's interstate transport provision. In this proposed rule, the EPA continues to observe that requiring NO X emissions reductions from stationary sources is an effective strategy for reducing regional ozone transport in the U.S. In Section VI of this proposed rule, EPA describes the multi-factor test that is used to determine NO X emissions reductions that are cost-effective and reduce interstate transport of ground-level ozone. Our analysis indicates that the EGU and non-EGU control requirements proposed in this rule will provide meaningful improvements in air quality at the downwind receptors. Based on the implementation schedule established in Section VII.A of this proposed rule, the EPA proposes to determine that the regulatory requirements included in the proposed rule are as expeditious as practicable and are aligned with the attainment schedule of downwind areas. 3. Health and Environmental Effects Exposure to ambient ozone causes a variety of negative effects on human health, vegetation, and ecosystems. In humans, acute and chronic exposure to ozone is associated with premature mortality and a number of morbidity effects, such as asthma exacerbation. In ecosystems, ozone exposure causes visible foliar injury, decreases plant growth, and affects ecosystem community composition. See EPA's October 2015 Regulatory Impact Analysis of the Final Revisions to the National Ambient Air Quality Standards for Ground-Level Ozone 59 in the docket for this proposal for more information on the human health and ecosystem effects associated with [Text truncated at 120,000 characters. The full text is on the page linked above.] --- Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/fr%3A2022-04551. Public record. Not legal advice.