# Federal “Good Neighbor Plan” for the 2015 Ozone National Ambient Air Quality Standards > Briefs, arguments, decisions, and more. URL: https://www.frixlaw.com/law-library/documents/fr%3A2023-05744 ## Record - **Collection:** Federal Register - **Document type:** Rule - **Published:** June 5, 2023 - **Citation:** 88 FR 36654 ## Text ENVIRONMENTAL PROTECTION AGENCY 40 CFR Parts 52, 75, 78, and 97 [EPA-HQ-OAR-2021-0668; FRL-8670-02-OAR] RIN 2060-AV51 Federal “Good Neighbor Plan” for the 2015 Ozone National Ambient Air Quality Standards AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: This action finalizes Federal Implementation Plan (FIP) requirements to address 23 states' obligations to eliminate significant contribution to nonattainment, or interference with maintenance, of the 2015 ozone National Ambient Air Quality Standards (NAAQS) in other states. The U.S. Environmental Protection Agency (EPA) is taking this action under the “good neighbor” or “interstate transport” provision of the Clean Air Act (CAA or Act). The Agency is defining the amount of ozone-precursor emissions (specifically, nitrogen oxides) that constitute significant contribution to nonattainment and interference with maintenance from these 23 states. With respect to fossil fuel-fired power plants in 22 states, this action will prohibit those emissions by implementing an allowance-based trading program beginning in the 2023 ozone season. With respect to certain other industrial stationary sources in 20 states, this action will prohibit those emissions through emissions limitations and associated requirements beginning in the 2026 ozone season. These industrial source types are: reciprocating internal combustion engines in Pipeline Transportation of Natural Gas; kilns in Cement and Cement Product Manufacturing; reheat furnaces in Iron and Steel Mills and Ferroalloy Manufacturing; furnaces in Glass and Glass Product Manufacturing; boilers in Iron and Steel Mills and Ferroalloy Manufacturing, Metal Ore Mining, Basic Chemical Manufacturing, Petroleum and Coal Products Manufacturing, and Pulp, Paper, and Paperboard Mills; and combustors and incinerators in Solid Waste Combustors and Incinerators. DATES: This final rule is effective on August 4, 2023. ADDRESSES: The EPA has established a docket for this rulemaking under Docket ID No. EPA-HQ-OAR-2021-0668. All documents in the docket are listed in the https://www.regulations.gov index. Although listed in the index, some information is not publicly available, e.g., Confidential Business Information or other information whose disclosure is restricted by statute. Certain other material, such as copyrighted material, will be publicly available only in hard copy. Publicly available docket materials are available either electronically at https://www.regulations.gov or in hard copy at the U.S. Environmental Protection Agency, EPA Docket Center, William Jefferson Clinton West Building, Room 3334, 1301 Constitution Ave. NW, Washington, DC. The Public Reading Room is open from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal holidays. The telephone number for the Public Reading Room is (202) 566-1744, and the telephone number for the Office of Air and Radiation Docket is (202) 566-1742. 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: (312) 886-4746; 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 ABC Associated Builders and Contractors ACS American Community Survey ACT Alternative Control Techniques AEO Annual Energy Outlook AQAT Air Quality Assessment Tool AQS Air Quality System BACT Best Available Control Technology BART Best Available Retrofit Technology BOF Basic Oxygen Furnace BPT Benefit Per Ton C1C2 Category 1 and Category 2 C3 Category 3 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 CDX Central Data Exchange CEDRI Compliance and Emissions Data Reporting Interface CEMS Continuous Emissions Monitoring Systems CES Clean Energy Standards CFB Circulating Fluidized Bed Units CHP Combined Heat and Power CMDB Control Measures Database CMV Commercial Marine Vehicle CoST Control Strategy Tool CPT Cost Per Ton CRA Congressional Review Act CSAPR Cross-State Air Pollution Rule DAHS Data Acquisition and Handling System DOE Department of Energy EAF Electric Arc Furnace EGU Electric Generating Unit EIA U.S. Energy Information Agency EIS Emissions Inventory System EISA Energy Independence and Security Act ELG Effluent Limitation Guidelines E.O. Executive Order EPA or the Agency United States Environmental Protection Agency ERT Electronic Reporting Tool FERC Federal Energy Regulatory Commission FFS Findings of Failure to Submit FIP Federal Implementation Plan GIS Geographic Information System g/hp-hr grams per horsepower per hour 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 IRA Inflation Reduction Act LAER Lowest Achievable Emission Rate LDC Local Distribution Company LME Low Mass Emissions LNB Low-NO X Burners MATS Mercury and Air Toxics Standards MCM Menu of Control Measures MDA8 Maximum Daily Average 8-Hour MJO Multi-Jurisdictional Organization MOU Memorandum of Understanding MOVES Motor Vehicle Emissions Simulator MSAT2 Mobile Source Air Toxics Rule MWC Municipal Waste Combustor NAAQS National Ambient Air Quality Standards NACAA National Association of Clean Air Agencies NAICS North American Industry Classification System NEEDS National Electric Energy Data System NEI National Emissions Inventory NERC North American Electric Reliability Corporation NESHAP National Emissions Standards for Hazardous Air Pollutants NMB Normalized Mean Bias NME Normalized Mean Error No SISNOSE No Significant Economic Impact on a Substantial Number of Small Entities Non-EGU Non-Electric Generating Unit NODA Notice of Data Availability NO X Nitrogen Oxides NREL National Renewable Energy Lab NSCR Non-Selective Catalytic Reduction NSPS New Source Performance Standard NSR New Source Review 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 PDF Portable Document Format PEMS Predictive Emissions Monitoring Systems PM 2.5 Fine Particulate Matter ppb parts per billion ppm parts per million ppmv parts per million by volume ppmvd parts per million by volume, dry PRA Paperwork Reduction Act PSD Prevention of Significant Deterioration PTE Potential to Emit RACT Reasonably Available Control Technology RATA Relative Accuracy Test Audit RCF Relative Contribution Factor RFA Regulatory Flexibility Act RICE Reciprocating Internal Combustion Engines ROP Rate of Progress RPS Renewable Portfolio Standards RRF Relative Response Factor RTC Response to Comments RTO Regional Transmission Organization SAFETEA Safe, Accountable, Flexible, Efficient, Transportation Equity Act SCC Source Classification Code SCR Selective Catalytic Reduction SIL Significant Impact Level SIP State Implementation Plan SMOKE Sparse Matrix Operator Kernel Emissions SNCR Selective Non-Catalytic Reduction SO 2 Sulfur Dioxide tpd ton per day TAS Treatment as State 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 the Regulatory Action 1. Emissions Limitations for EGUs Established by the Final Rule 2. Emissions Limitations for Industrial Stationary Point Sources Established by the Final Rule B. Summary of the Regulatory Framework of the Rule C. Costs and Benefits II. 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? D. What actions has the EPA previously issued to address regional ozone transport? III. Air Quality Issues Addressed and Overall Rule Approach 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. Final 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 Rule C. Other CAA Authorities for This Action 1. Withdrawal of Proposed Error Correction for Delaware 2. Application of Rule in Indian Country and Necessary or Appropriate Finding a. Indian Country Subject to Tribal Jurisdiction b. Indian Country Subject to State Implementation Planning Authority D. Severability IV. 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 a. EGU Emissions Inventories Supporting This Rule b. Impact of the Inflation Reduction Act on EGU Emissions 3. Development of Emissions Inventories for Stationary Industrial 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. Methodology for Projecting Future Year Ozone Design Values F. Pollutant Transport From Upwind States 1. Air Quality Modeling To Quantify Upwind State Ozone Contributions 2. Application of Ozone Contribution Screening Threshold a. States That Contribute Below the Screening Threshold b. States That Contribute Above the Screening Threshold G. Treatment of Certain Monitoring Sites in California and Implications for Oregon's Good Neighbor Obligations for the 2015 Ozone NAAQS V. 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 g. Other EGU Mitigation Measures 2. Non-EGU or Stationary Industrial Source NO X Mitigation Strategies 3. Other Stationary Sources NO X Mitigation Strategies a. Municipal Solid Waste Units b. Electric Generating Units Less Than or Equal to 25 MW 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 or Industrial Source Emissions Reduction Potential D. Assessing Cost, EGU and Industrial Source NO X Reductions, and Air Quality 1. EGU Assessment 2. Stationary Industrial Sources Assessment 3. Combined EGU and Non-EGU Assessment 4. Over-Control Analysis VI. 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 Stationary Industrial Source NO X Reductions Beginning in 2026 a. EGU Schedule for 2026 and Later Years b. Non-EGU or Industrial Source Schedule for 2026 and Later Years B. Regulatory Requirements for EGUs 1. Trading Program Background and Overview of 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 d. Responses to General Comments on the Revisions to the Group 3 Trading Program 2. Expansion of Geographic Scope 3. Applicability and Tentative Identification of Newly Affected Units 4. State Emissions Budgets a. Methodology for Determining Preset State Emissions Budgets for the 2023 through 2029 Control Periods b. Methodology for Determining Dynamic State Emissions Budgets for Control Periods in 2026 Onwards c. Final Preset 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 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. Monitoring and Reporting Requirements a. Monitor Certification Deadlines b. Additional Recordkeeping and Reporting Requirements 11. Designated Representative Requirements 12. 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 13. Conforming Revisions to Regulations for Other CSAPR Trading Programs C. Regulatory Requirements for Stationary Industrial Sources 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 at Basic Chemical Manufacturing, Petroleum and Coal Products Manufacturing, Pulp, Paper, and Paperboard Mills, Iron and Steel and Ferroalloys Manufacturing, and Metal Ore Mining Facilities a. Coal-fired Industrial Boilers b. Oil-fired Industrial Boilers c. Natural gas-fired Industrial Boilers 6. Municipal Waste Combustors 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 or Industrial Source Control Requirements E. Title V Permitting 1. Title V Permitting Considerations for EGUs 2. Title V Permitting Considerations for Industrial Stationary Sources F. Relationship to Other Emissions Trading and Ozone Transport Programs 1. NO X SIP Call 2. Acid Rain Program 3. Other CSAPR Trading Programs VII. Environmental Justice Analytical Considerations and Stakeholder Outreach and Engagement A. Introduction B. Analytical Considerations C. Outreach and Engagement VIII. Costs, Benefits, and Other Impacts of the Final Rule IX. Summary of 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 X. 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) 1. Information Collection Request for EGUs 2. Information Collection Request for Non-EGUs 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. Congressional Review Act L. Determinations Under CAA Section 307(b)(1) and (d) I. Executive Summary This final rule resolves the interstate transport obligations of 23 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 submit to EPA ozone infrastructure State Implementation Plan (SIP) revisions to fulfill interstate transport obligations for the 2015 ozone NAAQS by October 1, 2018. The EPA proposed the subject rule to address outstanding interstate ozone transport obligations for the 2015 ozone NAAQS in the Federal Register on April 6, 2022 (87 FR 20036). 1 See 80 FR 65291 (October 26, 2015). The EPA is making a finding that interstate transport of ozone precursor emissions from 23 upwind states (Alabama, Arkansas, California, Illinois, Indiana, Kentucky, Louisiana, Maryland, Michigan, Minnesota, Mississippi, Missouri, Nevada, New Jersey, New York, Ohio, Oklahoma, Pennsylvania, Texas, Utah, Virginia, West Virginia, and Wisconsin) is significantly contributing to nonattainment or interfering with maintenance of the 2015 ozone NAAQS in downwind states, based on projected ozone precursor emissions in the 2023 ozone season. The EPA is issuing FIP requirements to eliminate interstate transport of ozone precursor emissions from these 23 states that significantly contributes to nonattainment or interferes with maintenance of the NAAQS in downwind states. The EPA is not finalizing its proposed error correction for Delaware's ozone transport SIP, and we are deferring final action at this time on the proposed FIPs for Tennessee and Wyoming pending further review of the updated air quality and contribution modeling and analysis developed for this final action. As discussed in section III of this document, the EPA's updated analysis of 2023 suggests that the states of Arizona, Iowa, Kansas, and New Mexico may be significantly contributing to one or more nonattainment or maintenance receptors. The EPA is not making any final determinations with respect to these states in this action but intends to address these states, along with Tennessee and Wyoming, in a subsequent action or actions. The EPA is finalizing FIP requirements for 21 states for which the Agency has, in a separate action, disapproved (or partially disapproved) ozone transport SIP revisions that were 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, Texas, Utah, West Virginia, and Wisconsin. See 88 FR 9336. In this final rule, the EPA is issuing FIPs for two states—Pennsylvania and Virginia—for which the EPA issued Findings of Failure to Submit for 2015 ozone NAAQS transport SIPs. See 84 FR 66612 (December 5, 2019). Under CAA section 301(d)(4), the EPA is extending FIP requirements to apply in Indian country located within the upwind geography of the final 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 2 In general, specific tribal names or reservations are not identified separately in this final rule except as needed. See section III.C.2 of this document for further discussion about the application of this rule in Indian Country. This final rule defines ozone season nitrogen oxides (NO X ) emissions performance obligations for Electric Generating Unit (EGU) sources and fulfills those obligations by implementing an allowance-based ozone season trading program beginning in 2023. This rule also establishes emissions limitations beginning in 2026 for certain other industrial stationary sources (referred to generally as “non-Electric Generating Units” (non-EGUs)). Taken together, these regulatory requirements will fully eliminate the amount of emissions that constitute the covered states' significant contribution to nonattainment and interference with maintenance in downwind states for purposes of the 2015 ozone NAAQS. This final rule implements the necessary emissions reductions as follows. Under the FIP requirements, EGUs in 22 states (Alabama, Arkansas, Illinois, Indiana, Kentucky, Louisiana, Maryland, Michigan, Minnesota, Mississippi, Missouri, Nevada, New Jersey, New York, Ohio, Oklahoma, Pennsylvania, Texas, Utah, Virginia, West Virginia, and Wisconsin) are required 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 In addition to reflecting emissions reductions based on the Agency's determination of the necessary control stringency in this rule, the revised trading program includes several enhancements to the program's design to better ensure achievement of the selected control stringency on all days of the ozone season and over time. For 12 states already required to participate 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) under the Revised CSAPR Update (with respect to the 2008 ozone NAAQS), the FIPs are amended by the revisions to the Group 3 trading program regulations. For seven states currently covered by the CSAPR NO X Ozone Season Group 2 Trading Program under SIPs or FIPs, the EPA is issuing new FIPs for two states (Alabama and Missouri) and amending existing FIPs for five states (Arkansas, Mississippi, Oklahoma, 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. The EPA is issuing new FIPs for three states not currently covered by any CSAPR NO X ozone season trading program: Minnesota, Nevada, and Utah. 3 As explained in section V.C.1 of this document, the EPA is making a 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. This rulemaking requires emissions reductions in the selected control stringency to be achieved as expeditiously as practicable and, to the extent possible, by the next applicable nonattainment dates for downwind areas for the 2015 ozone NAAQS. Thus, initial emissions reductions from EGUs will be required beginning in the 2023 ozone season and prior to the August 3, 2024, attainment date for areas classified as Moderate nonattainment for the 2015 ozone NAAQS. The remaining emissions reduction obligations will be phased in as soon as possible thereafter. Substantial additional reductions from potential new post-combustion control installations at EGUs as well as from installation of new pollution controls at non-EGUs, also referred to in this action as industrial sources, will phase in beginning in the 2026 ozone season, associated with the August 3, 2027, attainment date for areas classified as Serious nonattainment for the 2015 ozone NAAQS. The EPA had proposed to require all emissions reductions to eliminate significant contribution to be in place by the 2026 ozone season. While we continue to view 2026 as the appropriate analytic year for purposes of applying the 4-step interstate transport framework, as discussed in section V.D.4 and VI.A.2 of this document, the final rule will allow individual facilities limited additional time to fully implement the required emissions reductions where the owner or operator demonstrates to the EPA's satisfaction that more rapid compliance is not possible. For EGUs, the emissions trading program budget stringency associated with retrofit of post-combustion controls will be phased in over two ozone seasons (2026-2027). For industrial sources, this final rule provides a process for individual facilities to seek a one year extension, with the possibility of up to two additional years, based on a specific showing of necessity. The EGU emissions reductions are based on the feasibility of control installation for EGUs in 19 states that remain linked to downwind nonattainment and maintenance receptors in 2026. These 19 states are: Arkansas, Illinois, Indiana, Kentucky, Louisiana, Maryland, Michigan, Mississippi, Missouri, Nevada, New Jersey, New York, Ohio, Oklahoma, Pennsylvania, Texas, Utah, Virginia, and West Virginia. The emissions reductions required for EGUs in these states are based primarily on the potential retrofit of additional post-combustion controls for NO X on most coal-fired EGUs and a portion of oil/gas-fired EGUs that are currently lacking such controls. The EPA is finalizing, with some modifications from proposal in response to comments, certain additional features in the allowance-based trading program approach for EGUs, including dynamic adjustments of the emissions budgets and recalibration of the allowance bank over time as well as backstop daily emissions rate limits for large coal-fired units. The purpose of these enhancements is to better ensure that the emissions control stringency the EPA found necessary to eliminate significant contribution at Step 3 of the 4-step interstate transport framework is maintained over time in Step 4 implementation and is durable to changes in the power sector. These enhancements ensure the elimination of significant contribution is maintained both in terms of geographical distribution (by limiting the degree to which individual sources can avoid making emissions reductions) and in terms of temporal distribution (by better ensuring emissions reductions are maintained throughout each ozone season, year over year). As we further discuss in section V.D of this document, these changes do not alter the stringency of the emissions trading program over time. Rather, they ensure that the trading program (as the method of implementation at Step 4) remains aligned with the determinations made at Step 3. These enhancements are further discussed in section VI.B of this document. The EPA is making a finding that NO X emissions from certain 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 is establishing emissions limitations beginning in 2026 for non-EGU sources located within 20 states: Arkansas, California, Illinois, Indiana, Kentucky, Louisiana, Maryland, Michigan, Mississippi, Missouri, Nevada, New Jersey, New York, Ohio, Oklahoma, Pennsylvania, Texas, Utah, Virginia, and West Virginia. The final rule establishes NO X emissions limitations during the ozone season for the following unit types for sources in non-EGU industries: 4 reciprocating internal combustion engines in Pipeline Transportation of Natural Gas; kilns in Cement and Cement Product Manufacturing; reheat furnaces in Iron and Steel Mills and Ferroalloy Manufacturing; furnaces in Glass and Glass Product Manufacturing; boilers in Iron and Steel Mills and Ferroalloy Manufacturing, Metal Ore Mining, Basic Chemical Manufacturing, Petroleum and Coal Products Manufacturing, and Pulp, Paper, and Paperboard Mills; and combustors and incinerators in Solid Waste Combustors and Incinerators. 4 We use the terms “emissions limitation” and “emissions limit” to refer to both numeric emissions limitations and control technology requirements that specify levels of emissions reductions to be achieved. 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 downwind 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 certain 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 III of this document 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. 5 6 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. 7 5 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. 6 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. 7 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. 8 Within 3 years of the EPA promulgating a new or revised NAAQS, all states are required to provide SIP submittals, often referred to as “infrastructure SIPs,” addressing certain requirements, including the good neighbor provision. See CAA section 110(a)(1) and (2). The EPA must either approve or disapprove such submittals or make a finding that a state has failed to submit a complete SIP revision. As with any other type of SIP under the Act, when the EPA disapproves an interstate transport SIP or finds that a state failed to submit an interstate transport SIP, the CAA requires the EPA to issue a FIP to directly implement the measures necessary to eliminate significant contribution under the good neighbor provision. See generally CAA section 110(k) and 110(c). As such, in this rule, the EPA is finalizing requirements to fully address good neighbor obligations for the covered states for the 2015 ozone NAAQS under its authority to promulgate FIPs under CAA section 110(c). By eliminating significant contribution from these upwind states, this rule 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. At any time after the effective date of this rule, states may submit a Good Neighbor SIP to replace the FIP requirements contained in this rule, subject to EPA approval under CAA section 110(a). 8 42 U.S.C. 7410(a)(2)(D)(i)(I). The EPA conducted air quality modeling for the 2023 and 2026 analytic years to identify (1) the downwind areas identified as “receptors” (which are associated with monitoring sites) 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. We use the term “downwind” to describe those states or areas where a receptor is located, and we use the term “upwind” to describe states whose emissions are linked to one or more receptors. States may be both downwind and upwind depending on the receptor or linkage in question. Section IV of this document provides a full description of the results of the EPA's updated air quality modeling and relevant analyses for the rulemaking, including a discussion of how updates to the modeling and air quality analysis following the proposed rule have resulted in some modest changes in the overall geography of the final rule. Based on the EPA's air quality analysis, the 23 upwind states covered in this action are linked above the 1 percent of the NAAQS threshold to downwind air quality problems in downwind states. The EPA intends to expeditiously review the updated air quality modeling and related analyses to address potential good neighbor requirements of six additional states—Arizona, Iowa, Kansas, New Mexico, Tennessee, and Wyoming—in a subsequent action. The EPA had previously approved 2015 ozone transport SIPs submitted by Oregon and Delaware, but in the proposed FIP action the EPA found these states potentially to be linked in the modeling supporting our proposal. We proposed to issue an error correction for our prior approval of Delaware's 2015 ozone transport SIP; however, in this final rule, the EPA is withdrawing the proposed error correction and the proposed FIP for Delaware, because our updated modeling for this final rule confirms that Delaware is not linked above the 1 percent of NAAQS threshold ( see section III.C.1 of this document for additional information). The EPA is deferring finalizing a finding at this time for Oregon ( see section IV.G of this document for additional information). 1. Emissions Limitations for EGUs Established by the Final Rule In this rule, the EPA is issuing FIP requirements that apply the provisions of the CSAPR NO X Ozone Season Group 3 Trading Program as revised in the rule to EGU sources within the borders of the following 22 states: Alabama, Arkansas, Illinois, Indiana, Kentucky, Louisiana, Maryland, Michigan, Minnesota, Mississippi, Missouri, Nevada, New Jersey, New York, Ohio, Oklahoma, Pennsylvania, Texas, Utah, Virginia, West Virginia, and Wisconsin. Implementation of the revised trading program provisions begins in the 2023 ozone season. The EPA is expanding the CSAPR NO X Ozone Season Group 3 Trading Program beginning in the 2023 ozone season. Specifically, the FIPs require power plants within the borders of the 22 states listed in the previous paragraph to participate in an expanded and 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 the following 12 states currently participating in the Group 3 Trading Program under existing FIPs remain in the program, with revised provisions beginning in the 2023 ozone season, under this rule: Illinois, Indiana, Kentucky, Louisiana, Maryland, Michigan, New Jersey, New York, Ohio, Pennsylvania, Virginia, and West Virginia. The FIPs also require affected EGUs within the borders of the following seven 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, Texas, and Wisconsin. 9 Finally, the EPA is issuing new FIPs for EGUs within the borders of three states not currently covered by any existing CSAPR trading program for seasonal NO X emissions: Minnesota, Nevada, and Utah. Sources in these states will enter the Group 3 trading program in the 2023 control period following the effective date of the final rule. 10 Refer to section VI.B of this document for details on EGU regulatory requirements. 9 Five of these seven states (Arkansas, Mississippi, Oklahoma, Texas, and Wisconsin) currently participate in the Federal Group 2 trading program pursuant to the FIPs finalized in the CSAPR Update. The FIPs required under this rule 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 required in this action constitute new FIPs for these states. The EPA will cease implementation of the state Group 2 trading programs included in the two states' SIPs on the effective date of this rule. 10 Three states, Kansas, Iowa, and Tennessee, will remain in the Group 2 Trading Program. 2. Emissions Limitations for Industrial Stationary Point Sources Established by the Final Rule The EPA is issuing FIP requirements that include new NO X emissions limitations for industrial or non-EGU sources in 20 states, with sources expected to demonstrate compliance no later than 2026. The EPA is requiring emissions reductions from non-EGU sources to address interstate transport obligations for the 2015 ozone NAAQS for the following 20 states: Arkansas, California, Illinois, Indiana, Kentucky, Louisiana, Maryland, Michigan, Mississippi, Missouri, Nevada, New Jersey, New York, Ohio, Oklahoma, Pennsylvania, Texas, Utah, Virginia and West Virginia. The EPA is establishing emissions limitations for the following unit types in non-EGU industries: reciprocating internal combustion engines in Pipeline Transportation of Natural Gas; kilns in Cement and Cement Product Manufacturing; reheat furnaces in Iron and Steel Mills and Ferroalloy Manufacturing; furnaces in Glass and Glass Product Manufacturing; boilers in Iron and Steel Mills and Ferroalloy Manufacturing, Metal Ore Mining, Basic Chemical Manufacturing, Petroleum and Coal Products Manufacturing, and Pulp, Paper, and Paperboard Mills; and combustors and incinerators in Solid Waste Combustors and Incinerators. Refer to Table II.A-1 for a list of North American Industry Classification System (NAICS) codes for each entity included for regulation under this rule. B. Summary of the Regulatory Framework of the Rule The EPA is applying the 4-step interstate transport framework developed and used in CSAPR, the CSAPR Update, the Revised CSAPR Update, and other previous ozone transport rules 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 define and implement good neighbor obligations for the 2015 ozone NAAQS. The four steps are as follows: (Step 1) identifying downwind receptors that are expected to have problems attaining or maintaining the NAAQS; (Step 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 rule as in prior transport rules beginning with CSAPR in 2011, above a contribution threshold of 1 percent of the NAAQS); (Step 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 through a multifactor analysis; and (Step 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. The remainder of this section provides a general overview of the EPA's application of the 4-step framework as it applies to the provisions of the rule; additional details regarding the EPA's approach are found in section III of this document. 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 and 2026. 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 of projected ozone concentrations was then repeated for 2026. 11 These 2 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, and August 3, 2027, for areas classified as Serious nonattainment. 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, the 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 4-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. 12 The EPA performed air quality modeling for 2032 in the proposed rulemaking, but 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. The modeling of 2032 done at proposal using the 2016v2 platform does not constitute or represent any final agency determinations respecting air quality conditions or regulatory judgments with respect to good neighbor obligations or any other CAA requirements. 13 See section IV.F of this document for explanation of EPA's use of the 1 percent of the NAAQS threshold in the Step 2 analysis. Based on the EPA's most recent air quality modeling and contribution analysis using 2023 as the analytic year, the EPA finds that the following 23 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, Illinois, Indiana, Kentucky, Louisiana, Maryland, Michigan, Minnesota, Mississippi, Missouri, Nevada, New Jersey, New York, Ohio, Oklahoma, Pennsylvania, Texas, Utah, Virginia, West Virginia, and Wisconsin. There are locations in California to which Oregon contributes greater than 1 percent of the NAAQS; the EPA proposed that downwind areas represented by these monitoring sites in California should not be considered interstate ozone transport receptors at Step 1. However, the EPA is deferring finalizing a finding at this time for Oregon ( see section IV.G of this document for additional information). Based on the air quality analysis presented in section IV of this document, the EPA finds that, with the exception of Alabama, Minnesota, and Wisconsin, the states found linked in 2023 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. As a result, the EPA's evaluation of significantly contributing emissions at Step 3 for Alabama, Minnesota, and Wisconsin is limited to emissions reductions achievable by the 2023 and 2024 ozone seasons. At the third step of the 4-step framework, the EPA applied a multifactor 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. The EPA is applying the multifactor test described in section V.A of this document to both EGU and industrial sources. The EPA assessed the potential emissions reductions in 2023 and 2026, 14 as well as in intervening and later years to determine the emissions reductions required to eliminate significant contribution in 2023 and future years where downwind areas are projected to have potential problems attaining or maintaining the 2015 ozone NAAQS. 14 The EPA included emissions reductions from the potential installation of SCRs at all affected large coal-fired EGUs in the 2026 analytic year for the purposes of assessing significant contribution to nonattainment and interference with maintenance, which is consistent with the associated attainment date. However, in response to comments identifying potential supply chain and outage scheduling challenges if the full breadth of these assumed SCR installations were to occur, the EPA is implementing half of this emissions reduction potential in 2026 ozone-season NO X budgets for states containing these EGUs and the other half of this emissions reduction potential in 2027 ozone-season NO X budgets for those states. 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 V of this document and supported by the “Technical Support Document (TSD) for the Final Federal Good Neighbor Plan for the 2015 Ozone National Ambient Air Quality Standard, Docket ID No. EPA-HQ-OAR-2021-0668, EGU NO X Mitigation Strategies Final Rule TSD” (Mar. 2023), hereinafter referred to as the EGU NO X Mitigation Strategies Final Rule TSD, included in the docket for this action, the EPA determines 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. See section V.B.1 of this document for a full discussion of EPA's analysis of NO X emissions mitigation strategies for EGU sources. The EPA is requiring control stringency levels that offer the most incremental NO X emissions reduction potential from EGUs—among the uniform mitigation measures assessed for the covered region—and the most corresponding downwind ozone air quality improvements to the extent feasible in each year analyzed. The EPA is making a finding 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 the 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. 15 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. 15 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 rulemaking, the EPA is addressing good neighbor obligations for the more protective 2015 ozone NAAQS, and the Agency observes ongoing and persistent contribution from upwind states to ozone nonattainment and maintenance receptors in downwind states under that NAAQS. As further discussed in section V of this document, 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. In this rule, the EPA is requiring emissions performance levels for 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 V of this document, the EPA finds 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 22 states linked to downwind nonattainment or maintenance in 2023 (Alabama, Arkansas, Illinois, Indiana, Kentucky, Louisiana, Maryland, Michigan, Minnesota, Mississippi, Missouri, Nevada, New Jersey, New York, Ohio, Oklahoma, Pennsylvania, Texas, Utah, Virginia, West Virginia, and Wisconsin). For 19 of those states that are also linked in 2026 (Arkansas, Illinois, Indiana, Kentucky, Louisiana, Maryland, Michigan, Mississippi, Missouri, Nevada, New Jersey, New York, Ohio, Oklahoma, Pennsylvania, Texas, Utah, Virginia, and West Virginia), the EPA is determining that the selected EGU control stringency also includes emissions reductions commensurate with the retrofit of SCR at coal-fired units of 100 MW or greater capacity (excepting circulating fluidized bed units (CFB)), new SNCR on coal-fired units of less than 100 MW capacity and on CFBs of any capacity size, 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, for the proposed FIP, the EPA evaluated air quality modeling information, annual emissions, and information about potential controls to determine which industries, beyond the power sector, could have the greatest impact in providing ozone air quality improvements in affected downwind states. Once the EPA identified the industries, the EPA used its Control Strategy Tool to identify potential emissions units and control measures and to estimate emissions reductions and compliance costs associated with application of non-EGU emissions control measures. The technical memorandum Screening Assessment of Potential Emissions Reductions, Air Quality Impacts, and Costs from Non-EGU Emissions Units for 2026 lays out the analytical framework and data used to prepare proxy estimates for 2026 of potentially affected non-EGU facilities and emissions units, emissions reductions, and costs. 16 17 This information helped shape the proposal and final rule. To further evaluate the industries and emissions unit types identified by the screening assessment and to establish the applicability criteria and proposed emissions limits, the EPA reviewed Reasonably Available Control Technology (RACT) rules, New Source Performance Standards (NSPS) rules, National Emissions Standards for Hazardous Air Pollutants (NESHAP) rules, existing technical studies, rules in approved SIPs, consent decrees, and permit limits. That evaluation is detailed in the “Technical Support Document (TSD) for the Proposed Rule, Docket ID No. EPA-HQ-OAR-2021-0668, Non-EGU Sectors TSD” (Dec. 2021), hereinafter referred to as the Proposed Non-EGU Sectors TSD, prepared for the proposed FIP. 18 16 The memorandum is available in the docket at https://www.regulations.gov/document/EPA-HQ-OAR-2021-0668-0150 . 17 This screening assessment was not intended to identify the specific emissions units subject to the proposed emissions limits for non-EGU sources but was intended to inform the development of the proposed rule by identifying proxies for (1) non-EGU emissions units that had emissions reduction potential, (2) potential controls for and emissions reductions from these emissions units, and (3) control costs from the potential controls on these emissions units. This information helped shape the proposed rule. 18 The TSD is available in the docket at https://www.regulations.gov/document/EPA-HQ-OAR-2021-0668-0145 . In this final rule, the EPA is retaining the industries and many of the emissions unit types included in the proposal in its findings of significant contribution at Step 3, as discussed in section V of this document. As discussed in the memorandum for the final rule, titled “Summary of Final Rule Applicability Criteria and Emissions Limits for Non-EGU Emissions Units, Assumed Control Technologies for Meeting the Final Emissions Limits, and Estimated Emissions Units, Emissions Reductions, and Costs,” the EPA uses the 2019 emissions inventory, the list of emissions units estimated to be captured by the applicability criteria, the assumed control technologies that would meet the emissions limits, and information on control efficiencies and default cost/ton values from the Control Measures Database, 19 to estimate NO X emissions reductions and costs for the year 2026. In this final rule, the EPA made changes to the applicability criteria and emissions limits following consideration of comments on the proposal and reassessed the overall non-EGU emissions reduction strategy based on the factors at Step 3 to render a judgment as to whether the level of emissions control that would be achievable from these units meets the criteria for “significant contribution.” In the final rule, we affirm our proposed determinations of which industries and emissions units are potentially impactful and warrant further analysis at Step 3, and we find that the available emissions reductions are cost-effective and make meaningful improvements at the identified downwind receptors. For a detailed discussion of the changes, between the proposal and this final rule, in emissions unit types included and in emissions limits, see section VI.C. of this document. 19 More information about the control measures database (CMDB) can be found at the following link: https://www.epa.gov/economic-and-cost-analysis-air-pollution-regulations/cost-analysis-modelstools-air-pollution . The EPA performed air quality analysis using the Ozone Air Quality Assessment Tool (AQAT) to evaluate the air quality improvements anticipated to result from the implementation of the selected EGU and non-EGU emissions reduction strategies. See section V.D of this document. 20 We also used AQAT to determine whether the emissions reductions for both EGUs and non-EGUs potentially create an “over-control” scenario. As in prior transport rules following the holdings in EME Homer City, overcontrol would be established if the record indicated that, for any given state, there is a less stringent emissions control approach for that state, by which (1) the expected ozone improvements would be sufficient to resolve all of the downwind receptor(s) to which that 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) to all of linked receptors. The EPA's over-control analysis, discussed in section V.D.4 of this document, shows that the control stringencies for EGU and non-EGU sources in this final rule 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. 20 The use of AQAT and other simplified modeling tools to generate “appropriately reliable projections of air quality conditions and contributions” when there is limited time to conduct full-scale photochemical grid modeling was upheld by the D.C. Circuit in MOG v. EPA, No. 21-1146 (D.C. Cir. March 3, 2023). The EPA has used AQAT for the purpose of air quality and overcontrol assessments at Step 3 in the prior CSAPR rulemakings, and we continue to find it reliable for such purposes. We discuss the calibration of AQAT for this action and the multiple sensitivity checks we performed to ensure its reliability in the Ozone Transport Policy Analysis Final Rule TSD in the docket. Because we were able to conduct a photochemical grid modeling run of the 2026 final rule policy scenario, these results are also included in the docket and confirm the regulatory conclusions reached with AQAT. See section VIII of this document and Appendix 3A of the Final Rule RIA for more information. 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 23 upwind states subject to EGU and non-EGU emissions reductions requirements under the rule. For additional details about the multi-factor test and the over-control analysis, see the document titled “Technical Support Document (TSD) for the Final Federal Good Neighbor Plan for the 2015 Ozone National Ambient Air Quality Standard, Docket ID No. EPA-HQ-OAR-2021-0668, Ozone Transport Policy Analysis Proposed Rule TSD” (Mar. 2023), hereinafter referred to as Ozone Transport Policy Analysis Final Rule TSD, included in the docket for this rulemaking. In this fourth step of the 4-step framework, the EPA is including enforceable measures in the promulgated FIPs to achieve the required emissions reductions in each of the 23 states. Specifically, the FIPs require covered power plants within the borders of 22 states (Alabama, Arkansas, Illinois, Indiana, Kentucky, Louisiana, Maryland, Michigan, Minnesota, Mississippi, Missouri, Nevada, New Jersey, New York, Ohio, Oklahoma, Pennsylvania, Texas, Utah, Virginia, West Virginia, and Wisconsin) 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 the following 12 states currently participating in the Group 3 Trading Program will remain in the program, with revised provisions beginning in the 2023 ozone season, under this rule: Illinois, Indiana, Kentucky, Louisiana, Maryland, Michigan, New Jersey, New York, Ohio, Pennsylvania, Virginia, and West Virginia. Affected EGUs within the borders of the following seven states currently covered by the CSAPR NO X Ozone Season Group 2 Trading Program (the “Group 2 trading program”)—Alabama, Arkansas, Mississippi, Missouri, Oklahoma, Texas, and Wisconsin—will transition from the Group 2 program to the revised Group 3 trading program beginning with the 2023 control period, 21 and affected EGUs within the borders of three states not currently covered by any CSAPR trading program for seasonal NO X emissions—Minnesota, Nevada, and Utah—will enter the Group 3 trading program in the 2023 control period following the effective date of the final rule. In addition, the EPA is revising other aspects of the Group 3 trading program to better ensure that this method of implementation at Step 4 provides a durable remedy for the elimination of the amount of emissions deemed to constitute significant contribution at Step 3 of the interstate transport framework. These enhancements, summarized later in this section, are designed to operate together to maintain that degree of control stringency over time, thus improving emissions performance at individual units and offering a necessary measure of assurance that NO X pollution controls will be operated throughout each ozone season, as described in section VI.B of this document. This rulemaking does not revise the budget stringency and geography of the existing CSAPR NO X Ozone Season Group 1 trading program. Aside from the seven states moving from the Group 2 trading program to the Group 3 trading program under the final rule, this rule otherwise leaves unchanged the budget stringency of the existing CSAPR NO X Ozone Season Group 2 trading program. 21 The EPA will deem participation in the Group 3 trading program by the EGUs in these seven states as also addressing the respective states' good neighbor obligations with respect to the 2008 ozone NAAQS (for all seven states), the 1997 ozone NAAQS (for all the states except Texas), and the 1979 ozone NAAQS (for Alabama and Missouri) 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 establishing preset ozone season NO X emissions budgets for each ozone season from 2023 through 2029, using generally the same Group 3 trading program budget-setting methodology used in the Revised CSAPR Update, as explained in section VI.B of this document and as shown in Table I.B-1. The preset budgets for the 2026 through 2029 ozone seasons incorporate EGU emissions reductions to eliminate significant contribution and also take into account a substantial number of known retirements over that period to ensure the elimination of significant contribution is maintained as intended by this rule. These budgets serve as floors and may be supplanted by a budget that the EPA calculates for that control period using more recent information (a “dynamic budget”) if that dynamic budget yields a higher level of allowable emissions—still consistent with the Step 3 level of emissions control stringency—than the preset budget. As reflected in Table I.B-1, and accounting for both the stringency of the rule and known fleet change, the 2026 preset budget is 23 percent lower than the 2025 preset budget; the 2027 preset budget is 20 percent lower than the 2026 preset budget; the 2028 preset budget is 4 percent lower than the 2027 preset budget; and the 2029 preset budget is 8 percent lower than the 2028 preset budget. While it is possible that additional EGUs may seek to retire in this 2026-2029 period than are currently scheduled and captured in the preset emissions budgets, it is also possible that EGUs with currently scheduled retirements may adjust their retirement timing to accommodate the timing of replacement generation and/or transmission upgrades necessitated by their retirement. While the EPA designed this final rule to provide preset budgets through 2029 to incorporate known retirement-related emissions reductions to ensure the elimination of significant contribution as identified at Step 3 is maintained over time, the use of these floors also provides generators and grid operators enhanced certainty regarding the minimum amount of allowable NO X emissions for reliability planning through the 2020s. By providing the opportunity for dynamic budgets to subsequently calibrate budgets to any unforeseen increases in fleet demand, it also ensures this rule will not interfere with ongoing retirement scheduling or adjustments and thus is robust to future uncertainty during a transition period. The EPA also believes the likelihood and magnitude of a scenario in which a state's preset emissions budgets during this period would authorize more emissions than the corresponding dynamic budget is low. As described elsewhere, dynamic budgets are incorporated to best calibrate the rule's stringency to future unknown changes to the fleet. The circumstances in which a dynamic budget would produce a level of allowable emissions less than preset budgets is most pronounced for future periods in which there is a high degree of unknown retirements (increasing the risk that budgets are not appropriately calibrated to the reduced fossil fuel heat input post retirement). However, the 2026-2029 period presents a case where retirement planning has been announced with greater lead time than normal due to a combination of utility 2030 decarbonization commitments, and Effluent Limitation Guideline (ELG) and Coal Combustion Residual (CCR) alternative compliance pathways available to units planning to cease combustion of coal by December 31, 2028. For each of these existing rules, facilities that are planning to retire have already conveyed that intention to EPA in order to take advantage of the alternative compliance pathways available to such facilities. 22 Therefore, the likelihood of unknown retirements—leading to lower dynamic budgets—is much lower than typical for this time horizon. This makes EPA's balanced use of preset emissions budgets or dynamic budgets if they exceed preset levels a reasonable mechanism to accommodate planning and fleet transition dynamics during this period. The need and reasoning for the limited-period preset budget floor is further discussed in section VI.B.4. 22 Notices of Planned Participation for the ELG Reconsideration Rule were due October 31, 2021 (85 FR 64708, 64679). For the CCR Action, facilities had to indicate their future plans to cease receipt of waste by April 11, 2021 (85 FR 53517). For control periods in 2030 and thereafter, the emissions budgets will be the amounts calculated for each state and noticed to the public roughly one year before the control period, using the dynamic budget-setting methodology. In this manner, the stringency of the program will be secured and sustained in the dynamic budgets of this program, regardless of whatever EGU transition activities ultimately occur in this 2026-2029 transition period. Table I.B-1—Preset CSAPR NO X Ozone Season Group 3 State Emissions Budgets (tons) for 2023 Through 2029 Control Periods * State 2023 State budget 2024 State budget 2025 State budget 2026 State budget ** 2027 State budget ** 2028 State budget ** 2029 State budget ** Alabama 6,379 6,489 6,489 6,339 6,236 6,236 5,105 Arkansas 8,927 8,927 8,927 6,365 4,031 4,031 3,582 Illinois 7,474 7,325 7,325 5,889 5,363 4,555 4,050 Indiana 12,440 11,413 11,413 8,410 8,135 7,280 5,808 Kentucky 13,601 12,999 12,472 10,190 7,908 7,837 7,392 Louisiana 9,363 9,363 9,107 6,370 3,792 3,792 3,639 Maryland 1,206 1,206 1,206 842 842 842 842 Michigan 10,727 10,275 10,275 6,743 5,691 5,691 4,656 Minnesota 5,504 4,058 4,058 4,058 2,905 2,905 2,578 Mississippi 6,210 5,058 5,037 3,484 2,084 1,752 1,752 Missouri 12,598 11,116 11,116 9,248 7,329 7,329 7,329 Nevada 2,368 2,589 2,545 1,142 1,113 1,113 880 New Jersey 773 773 773 773 773 773 773 New York 3,912 3,912 3,912 3,650 3,388 3,388 3,388 Ohio 9,110 7,929 7,929 7,929 7,929 6,911 6,409 Oklahoma 10,271 9,384 9,376 6,631 3,917 3,917 3,917 Pennsylvania 8,138 8,138 8,138 7,512 7,158 7,158 4,828 Texas 40,134 40,134 38,542 31,123 23,009 21,623 20,635 Utah 15,755 15,917 15,917 6,258 2,593 2,593 2,593 Virginia 3,143 2,756 2,756 2,565 2,373 2,373 1,951 West Virginia 13,791 11,958 11,958 10,818 9,678 9,678 9,678 Wisconsin 6,295 6,295 5,988 4,990 3,416 3,416 3,416 Total 208,119 198,014 195,259 151,329 119,663 115,193 105,201 * Further information on the state-level emissions budget calculations pertaining to Table I.B-1 is provided in section VI.B.4 of this document as well as the Ozone Transport Policy Analysis Final Rule TSD. Further information on the 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 VI.B.9 of this document. ** As described in section VI of this document, the budget for these years will be subsequently determined and equal the greater of the value above or that derived from the dynamic budget methodology. The budget-setting methodology that the EPA will use to determine dynamic budgets for each control period starting with 2026 is an extension of the methodology used to determine the preset budgets and will be used routinely to determine emissions budgets for each future control period 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. The stringency of the dynamic emissions budgets will 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. As already noted, for the control periods in which both preset budgets and dynamic budgets are determined for a state ( i.e., 2026 through 2029), the state's dynamic budget will apply only if it is higher than the state's preset budget. See section VI.B of this document for additional discussion of the EPA's method for adjusting emissions budgets to ensure elimination of significant contribution from EGU sources in the linked upwind states. In conjunction with the levels of the emissions budgets, the carryover of unused allowances for use in future control periods as banked allowances affects the ability of a trading program to maintain the rule's selected control stringency and related EGU effective emissions rate performance level as the EGU fleet evolves over time. Unrestricted banking of allowances allows what might otherwise be temporary surpluses of allowances in some individual control periods to accumulate into a long-term allowance surplus that reduces allowance prices and weakens the trading program's incentives to control emissions. To prevent this outcome, the EPA is also revising the Group 3 trading program by adding provisions that establish a routine recalibration process for banked allowances using a target percentage of 21 percent for the 2024-2029 control periods and 10.5 percent for control periods in 2030 and later years. As an enhancement to the structure of the trading program originally promulgated in the Revised CSAPR Update, the EPA is also establishing backstop daily emissions rates for coal steam EGUs greater than or equal to 100 MW in covered states. Starting with the 2024 control period, a 3-for-1 allowance surrender ratio (instead of the usual 1-for-1 surrender ratio) will apply to emissions during the ozone season from any large coal-fired EGU with existing SCR controls exceeding by more than 50 tons a daily average NO X emissions rate of 0.14 lb/mmBtu. The daily average emissions rate provisions will apply to large coal-fired EGUs without existing SCR controls starting with the second control period in which newly installed SCR controls are operational at the unit, but not later than the 2030 control period. The backstop daily emissions rates work in tandem with the ozone season emissions budgets to ensure the elimination of significant contribution as determined at Step 3 is maintained over time and more consistently throughout each ozone season. They will offer downwind receptor areas a necessary measure of assurance that they will be protected on a daily basis during the ozone season by more continuous and consistent 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. 23 In addition to maintaining a mass-based seasonal requirement, this rule will achieve a much more consistent level of emissions control in line with our Step 3 determination of significant contribution while maintaining compliance flexibility consistent with that determination. These trading program improvements will promote consistent emissions control performance across the power sector in the linked upwind states, which protects communities living in downwind ozone nonattainment areas from exceedances of the NAAQS that might otherwise occur. 23 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 is including enforceable emissions control requirements that will apply during the ozone season (annually from May to September) for nine non-EGU industries in the promulgated FIPs to achieve the required emissions reductions in 20 states with remaining interstate transport obligations for the 2015 ozone NAAQS in 2026: Arkansas, California, Illinois, Indiana, Kentucky, Louisiana, Maryland, Michigan, Mississippi, Missouri, Nevada, New Jersey, New York, Ohio, Oklahoma, Pennsylvania, Texas, Utah, Virginia, and West Virginia. These requirements would apply to all existing emissions units and to any future emissions units constructed in the covered states that meet the relevant applicability criteria. Thus, the emissions limitations for non-EGU sources and associated compliance requirements would apply in all 20 states listed in this paragraph, even if some of these states do not currently have any existing emissions units meeting the applicability criteria for the identified industries. Based on our evaluation of the time required to install controls at the types of non-EGU sources covered by this rule, the EPA has identified the 2026 ozone season as a reasonable compliance date for industrial sources. The EPA is therefore finalizing control requirements for non-EGU sources that take effect in 2026. However, in recognition of comments and additional information indicating that not all facilities may be capable of meeting the control requirements by that time, the final rule provides a process by which the EPA may grant compliance extensions of up to 1 year, which if approved by the EPA, would require compliance no later than the 2027 ozone season, followed by an additional possible extension of up to 2 more years, where specific criteria are met. For sources located in the 20 states listed in the previous paragraph, the EPA is finalizing the NO X emissions limits listed in Table I.B-2 for reciprocating internal combustion engines in Pipeline Transportation of Natural Gas; the NO X emissions limits listed in Table I.B-3 for kilns in Cement and Cement Product Manufacturing; the NO X emissions limits listed in Table I.B-4 for reheat furnaces in Iron and Steel Mills and Ferroalloy Manufacturing; the NO X emissions limits listed in Table I.B-5 for furnaces in Glass and Glass Product Manufacturing; the NO X emissions limits listed in Table I.B-6 for boilers in Iron and Steel Mills and Ferroalloy Manufacturing, Metal Ore Mining, Basic Chemical Manufacturing, Petroleum and Coal Products Manufacturing, and Pulp, Paper, and Paperboard Mills; and the NO X emissions limits listed in Table I.B-7 for combustors and incinerators in Solid Waste Combustors or Incinerators. Table I.B-2—Summary of NO X Emissions Limits for Pipeline Transportation of Natural Gas Engine type and fuel NO X emissions limit (g/hp-hr) Natural Gas Fired Four Stroke Rich Burn 1.0 Natural Gas Fired Four Stroke Lean Burn 1.5 Natural Gas Fired Two Stroke Lean Burn 3.0 Table I.B-3—Summary of NO X Emissions Limits for Kiln Types in Cement and Concrete Product Manufacturing Kiln type 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 Based on evaluation of comments received, the EPA is not, at this time, finalizing the source cap limit as proposed at 87 FR 20046 ( see section VII.C.2 of the April 6, 2022, Proposal). Table I.B-4—Summary of NO X Control Requirements for Iron and Steel and Ferroalloy Emissions Units Emissions unit NO X emissions standard or requirement (lb/mmBtu) Reheat furnace Test and set limit based on installation of Low-NO X Burners. Table I.B-5—Summary of NO X Emissions Limits for Furnace Unit Types in Glass and Glass Product Manufacturing Furnace type 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 7.0 Table I.B-6—Summary of NO X Emissions Limits for Boilers in Iron and Steel and Ferroalloy Manufacturing, Metal Ore Mining, 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 Table I.B-7—Summary of NO X Emissions Limits for Combustors and Incinerators in Solid Waste Combustors or Incinerators Combustor or incinerator, averaging period NO X emissions limit (ppmvd) ppmvd on a 24-hour block averaging period 110 ppmvd on a 30-day rolling averaging period 105 Section VI.C of this document provides an overview of the applicability criteria, compliance assurance requirements, and the EPA's rationale for establishing these emissions limits and control requirements for each of the non-EGU industries covered by the rule. The remainder of this preamble is organized as follows: section II of this document outlines general applicability criteria and describes the EPA's legal authority for this rule and the relationship of the rule to previous interstate ozone transport rulemakings. Section III of this document describes the human health and environmental challenges posed by interstate transport contributions to ozone air quality problems, as well as the EPA's overall approach for addressing interstate transport for the 2015 ozone NAAQS in this rule. Section IV of this document describes the Agency's analyses of air quality data to inform this rulemaking, including descriptions of the air quality modeling platform and emissions inventories used in the rule, as well as the EPA's methods for identifying downwind air quality problems and upwind states' ozone transport contributions to downwind states. Section V of this document describes the EPA's approach to quantifying upwind states' obligations in the form of EGU NO X control stringencies and non-EGU emissions limits. Section VI of this document 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 VII of this document discusses the environmental justice analysis of the rule, as well as outreach and engagement efforts. Section VIII of this document describes the expected costs, benefits, and other impacts of this rule. Section IX of this document provides a summary of changes to the existing regulatory text applicable to the EGUs covered by this rule; and section X of this document discusses the statutory and executive orders affecting this rulemaking. C. Costs and Benefits A summary of the key results of the cost-benefit analysis that was prepared for this final 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 recommended by OMB's Circular A-4, of the health and climate benefits, compliance costs, and net benefits of the final rule, in 2016 dollars, discounted to 2023. The estimated monetized net benefits are the estimated monetized benefits minus the estimated monetized costs of the final rule. These results present an incomplete overview of the effects of the rule because important categories of benefits—including benefits from reducing 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 rule to be more net beneficial than this table reflects. Table I.C-1—Estimated Monetized Health and Climate Benefits, Compliance Costs, and Net Benefits of the Final Rule, 2023 Through 2042 [Millions 2016$, discounted to 2023] a 3% Discount rate 7% Discount rate Present Value: Health Benefits b $200,000 $130,000 Climate Benefits c 15,000 15,000 Compliance Costs d 14,000 9,400 Net Benefits 200,000 140,000 Equivalent Annualized Value: Health Benefits 13,000 12,000 Climate Benefits 970 970 Compliance Costs 910 770 Net Benefits 13,000 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 ozone and PM 2.5 concentrations. The health benefits are associated with two 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. c Climate benefits are calculated using four different estimates of the social cost of carbon (SC-CO 2 (model average at 2.5 percent, 3 percent, and 5 percent discount rates; 95th percentile at 3 percent discount rate). For presentational purposes in this table, the climate benefits associated with the average SC-CO 2 at a 3-percent discount rate are used in the columns displaying results of other costs and benefits that are discounted at either a 3-percent or 7-percent discount rate. d The costs presented in this table are consistent with the costs presented in Chapter 4 of the Regulatory Impact Analysis (RIA). To estimate these annualized costs for EGUs, the 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 percent real discount rate consistent with the rate used in IPM's objective function for cost-minimization. For further information on the discount rate use, please see Chapter 4, Table 4-8 in the RIA. As shown in Table I.C-1, the PV of the monetized health benefits, associated with reductions in ozone and PM 2.5 concentrations, of this final rule, discounted at a 3-percent discount rate, is estimated to be about $200 billion ($200,000 million), with an EAV of about $13 billion ($13,000 million). At a 7-percent discount rate, the PV of the monetized health benefits is estimated to be $130 billion ($130,000 million), with an EAV of about $12 billion ($12,000 million). The PV of the monetized climate benefits, associated with reductions in GHG emissions, of this final rule, discounted at a 3-percent discount rate, is estimated to be about $15 billion ($15,000 million), with an EAV of about $970 million. The PV of the monetized compliance costs, discounted at a 3-percent rate, is estimated to be about $14 billion ($14,000 million), with an EAV of about $910 million. At a 7-percent discount rate, the PV of the compliance costs is estimated to be about $9.4 billion ($9,400 million), with an EAV of about $770 million. II. General Information A. Does this action apply to me? This rule affects EGU and non-EGU sources, and regulates the groups identified in Table II.A-1. Table II.A-1—Regulated Groups Industry group NAICS Fossil fuel-fired electric power generation 221112 Pipeline Transportation of Natural Gas 4862 Metal Ore Mining 2122 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 Solid Waste Combustors and Incinerators 562213 This table is not intended to be exhaustive, but rather provides a guide for readers regarding entities likely to be regulated by this rule. This table lists the types of entities that the EPA is now aware could potentially be regulated by this rule. Other types of entities not listed in the table could also be regulated. To determine whether your EGU entity is regulated by this rule, you should carefully examine the applicability criteria found in 40 CFR 97.1004, which are unchanged in this rule. If you have questions regarding the applicability of this 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 finds that emissions reductions are required from EGU and non-EGU sources in a total of 23 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 FIP requirements for 23 states: Alabama, Arkansas, California, Illinois, Indiana, Kentucky, Louisiana, Maryland, Michigan, Minnesota, Mississippi, Missouri, Nevada, New Jersey, New York, Ohio, Oklahoma, Pennsylvania, Texas, Utah, Virginia, West Virginia, and Wisconsin. The EPA is revising the existing CSAPR Group 3 Trading Program to include additional states beginning in the 2023 ozone season. EGUs in three states not currently covered by any CSAPR trading program for seasonal NO X emissions—Minnesota, Nevada, and Utah—will be added to the CSAPR Group 3 Trading Program under this rule. EGUs in twelve states currently participating in the Group 3 Trading Program will remain in the program under this rule: Illinois, Indiana, Kentucky, Louisiana, Maryland, Michigan, New Jersey, New York, Ohio, Pennsylvania, Virginia, and West Virginia. EGUs in seven states (Alabama, Arkansas, Mississippi, Missouri, Oklahoma, Texas, and Wisconsin) will transition from the CSAPR Group 2 Trading Program to the CSAPR Group 3 Trading Program under this rule beginning in the 2023 ozone season. The EPA is establishing 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 is establishing 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 establishing a backstop daily emissions rate of 0.14 lb/mmBtu for coal-fired steam units greater than or equal to 100 MW in covered states. The backstop emissions rate will first apply in 2024 for coal-fired steam sources with existing SCRs, and in the second control period in which a new SCR operates, but not later than 2030, for those currently without SCRs. This rule establishes emissions limitations for non-EGU sources in 20 states: Arkansas, California, Illinois, Indiana, Kentucky, Louisiana, Maryland, Michigan, Mississippi, Missouri, Nevada, New Jersey, New York, Ohio, Oklahoma, Pennsylvania, Texas, Utah, Virginia, and West Virginia. In these states, the EPA is establishing control requirements for the following unit types in non-EGU industries: reciprocating internal combustion engines in Pipeline Transportation of Natural Gas; kilns in Cement and Cement Product Manufacturing; reheat furnaces in Iron and Steel Mills and Ferroalloy Manufacturing; furnaces in Glass and Glass Product Manufacturing; boilers in Iron and Steel Mills and Ferroalloy Manufacturing, Metal Ore Mining, Basic Chemical Manufacturing, Petroleum and Coal Products Manufacturing, and Pulp, Paper, and Paperboard Mills; and combustors and incinerators in Solid Waste Combustors and Incinerators. See Table II.A-1 in this document for a list of NAICS codes for each entity included for regulation in this rule. This rule reduces 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 air quality issues addressed by this rule are included in section III of this document. C. What is the Agency's legal authority for taking this action? The statutory authority for this 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 rule. The most relevant portions of CAA section 110 are subsections 110(a)(1), 110(a)(2) (including 110(a)(2)(D)(i)(I)) and 110(c)(1)). 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. 24 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. 25 24 42 U.S.C. 7410(a)(1). 25 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. 26 It includes a list of specific elements that “[e]ach such plan” must address. 27 26 42 U.S.C. 7410(a)(2). 27 The 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 2 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. 28 28 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 rule. 29 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].” 30 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.” 29 42 U.S.C. 7410(a)(2)(D)(i)(I). 30 Id. Once the EPA promulgates a NAAQS, the EPA must designate areas as being in “attainment” or “nonattainment” of the NAAQS, or “unclassifiable.” CAA section 107(d). 31 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. 32 In general, states with nonattainment areas classified as Moderate or higher must submit plans to the EPA to bring these areas into attainment according to the statutory schedule. CAA section 182. 33 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). 34 31 42 U.S.C. 7407(d). 32 42 U.S.C. 7511, 7511a. 33 42 U.S.C. 7511a. 34 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. 35 Pursuant to this section, the 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 to make certain other changes to its regulations under 40 CFR parts 52, 75, 78, and 97, to effectuate the purposes of the Act. Such changes are discussed in section IX of this document. 35 42 U.S.C. 7601(a)(1). Tribes are not required to submit state implementation plans. However, as explained in the 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 the EPA's approval of, an implementation plan. See 40 CFR 49.11(a); see also CAA section 301(d)(4). 36 In the proposed rule, the EPA proposed an “appropriate or necessary” finding under CAA section 301(d) and proposed tribal FIP(s) as necessary to implement the relevant requirements. The EPA is finalizing these determinations, as further discussed in section III.C.2 of this document. 36 42 U.S.C. 7601(d)(4). D. What actions has the EPA previously issued to address regional ozone transport? The EPA has issued several previous 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. 37 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. 38 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). 37 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). 38 “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 the EPA's most recent trading programs are discussed in section VI.B.1.a of this document. The EPA's next rule addressing the good neighbor provision, CAIR, was promulgated in 2005 and addressed both the 1997 fine particulate matter (PM 2.5 ) NAAQS and 1997 ozone NAAQS. 39 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. 40 On March 15, 2006, the EPA promulgated FIPs to implement the emissions reductions required by CAIR. 41 CAIR was remanded to EPA by the D.C. Circuit in North Carolina v. EPA, 531 F.3d 896 (D.C. Cir.), modified on reh'g, 550 F.3d 1176 (D.C. Cir. 2008). 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. 42 39 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). 40 70 FR 21147 (April 25, 2005). 41 71 FR 25328 (April 28, 2006). 42 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. 43 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. 44 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. 43 76 FR 48208. 44 CSAPR was revised by several rulemakings after its initial promulgation 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. 45 However, this decision was reversed in April 2014 by the Supreme Court, which largely upheld the rule, including the 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 the EPA's interpretation of various statutory provisions and the 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 the 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. 46 45 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 the 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). 46 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. 47 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. 48 The EPA aligned the analysis and implementation of the CSAPR Update with the 2017 ozone season to assist downwind states with timely attainment of the 2008 ozone NAAQS. 49 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. 47 81 FR 74504. 48 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. 49 81 FR 74516. The 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. 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. 50 50 Determination Regarding Good Neighbor Obligations for the 2008 Ozone National Ambient Air Quality Standard, 83 FR 65878, 65882 (December 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 because 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. 51 51 Subsequently, the D.C. Circuit made clear in a decision reviewing the 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. 52 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 would 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 the 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 the EPA, would replace the Revised CSAPR Update FIP for that state. 52 Revised Cross-State Air Pollution Rule Update for the 2008 Ozone NAAQS, 86 FR 23054 (April 30, 2021). On March 3, 2023, the D.C. Circuit Court of Appeals denied the Midwest Ozone Group's (MOG) petition for review of the Revised CSAPR Update. MOG v. EPA, No. 21-1146 (D.C. Cir. March 3, 2023). The court noted that it has “exhaustively” addressed the interstate transport framework before, citing relevant cases, and “incorporate them herein by reference.” Slip Op. 1 n.1. In response to MOG's arguments, the court upheld the Agency's air quality analysis. Id. at 10-11. The court noted that in light of the statutory timing framework and court-ordered schedule the EPA was under, the Agency's methodological choices were reasonable and provided “an appropriately reliable projection of air quality conditions and contributions in 2021.” Id. at 11-12. III. Air Quality Issues Addressed and Overall Rule Approach 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. 53 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). 54 In general, areas that exceed the ozone standard are designated as nonattainment areas, pursuant to the designations process under CAA section 107(d), and are subject to heightened planning requirements depending on the severity of their nonattainment classification, see CAA sections 181, 182. 53 80 FR 65291. 54 40 CFR part 50, appendix P. 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 Greenhouse Gas 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. 55 (80 FR 65300). The U.S. Global Change Research Program's Impacts of Climate Change on Human Health in the United States: A Scientific Assessment 56 and Impacts, Risks, and Adaptation in the United States: Fourth National Climate Assessment, Volume II 57 reinforced these findings. 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. 58 59 60 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). The EPA responds to comments received on the impacts of climate change on ozone formation in section 11 of the Response to Comments ( RTC ) document. 55 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. O3 by scenario and across models and years, within the overall signal of higher summer O3 concentrations in a warmer climate. 56 U.S. Global Change Research Program (USGCRP), 2016: The Impacts of Climate Change on Human Health in the United States: A Scientific Assessment. Crimmins, A., J. Balbus, J.L. Gamble, C.B. Beard, J.E. Bell, D. Dodgen, R.J. Eisen, N. Fann, M.D. Hawkins, S.C. Herring, L. Jantarasami, D.M. Mills, S. Saha, M.C. Sarofim, J. Trtanj, and L. Ziska, Eds. U.S. Global Change Research Program, Washington, DC, 312 pp. https://dx.doi.org/10.7930/J0R49NQX . 57 USGCRP, 2018: 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, 1515 pp. doi: 10.7930/NCA4.2018. 58 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 59 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. 60 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. 61 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. 61 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, in conjunction with variable meteorological conditions. 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 62 continue to show the importance of NO X emissions for ozone transport. This analysis is included in the docket for this rulemaking. 62 Available in the docket for the October 2015 Revisions to the National Ambient Air Quality Standards for Ground-Level Ozone at https://www.regulations.gov/docket/EPA-HQ-OAR-2008-0699 . 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 of the 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. 63 63 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 , the 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. 64 The EPA and others have long regarded NO X to be the more significant ozone precursor in the context of interstate ozone transport. 65 64 “Ozone Air Pollution.” Introduction to Atmospheric Chemistry, by Daniel J. Jacob, Princeton University Press, Princeton, New Jersey, 1999, pp. 231-244. 65 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 rule. As described in section V.A of this document, 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 demonstrates that regional ozone concentrations affecting the vast majority of the downwind areas of air quality concern are NO X -limited, rather than VOC-limited. Therefore, the 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. The potential impacts of NO X mitigation strategies from other sources are discussed in section V.B of this document. In section V of this document, the 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 included in this rule will provide meaningful improvements in air quality at the downwind receptors. Based on the implementation schedule established in section VI.A of this document, the EPA finds that the regulatory requirements included in the 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 prema [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%3A2023-05744. Public record. Not legal advice.