# Air Quality Implementation Plans; California; San Diego County; 2008 and 2015 8-Hour Ozone Nonattainment Area Requirements > Briefs, arguments, decisions, and more. URL: https://www.frixlaw.com/law-library/documents/fr%3A2023-27513 ## Record - **Collection:** Federal Register - **Document type:** Proposed Rule - **Published:** December 19, 2023 - **Citation:** 88 FR 87850 ## Text ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 52 [EPA-R09-OAR-2021-0135; FRL-9538-02-R9] Air Quality Implementation Plans; California; San Diego County; 2008 and 2015 8-Hour Ozone Nonattainment Area Requirements AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule. SUMMARY: The Environmental Protection Agency (EPA) is proposing to approve portions of two state implementation plan (SIP) revisions submitted by the State of California to meet Clean Air Act requirements for the 2008 8-hour ozone national ambient air quality standards (NAAQS or “standards”) and the 2015 8-hour ozone NAAQS in the San Diego County ozone nonattainment area (“San Diego County area” or “area”). The first SIP revision, “2020 Plan for Attaining the National Ambient Air Quality Standards for Ozone in San Diego County” (“2020 San Diego County Ozone SIP” or “2020 Plan”), addresses most of the SIP requirements for the area. The second SIP revision, referred to as the “Smog Check Certification,” supplements the motor vehicle inspection and maintenance program portion of the 2020 Plan. The EPA is proposing to approve the 2020 Plan, and the San Diego County portion of the Smog Check Certification, as meeting all the applicable ozone nonattainment area requirements for the 2008 and 2015 8-hour ozone NAAQS addressed by the plan except for the emissions statement requirement that the EPA previously found to have been met and the contingency measure requirements, for which the EPA is deferring action. DATES: Comments must be received on or before January 18, 2024. ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R09-OAR-2021-0135 at https://www.regulations.gov. For comments submitted at Regulations.gov, follow the online instructions for submitting comments. Once submitted, comments cannot be edited or removed from Regulations.gov . The EPA may publish any comment received to its public docket. Do not submit electronically any information you consider to be Confidential Business Information (CBI) or other information whose disclosure is restricted by statute. Multimedia submissions (audio, video, etc.) must be accompanied by a written comment. The written comment is considered the official comment and should include discussion of all points you wish to make. The EPA will generally not consider comments or comment contents located outside of the primary submission ( i.e., on the web, cloud, or other file sharing system). For additional submission methods, please contact the person identified in the FOR FURTHER INFORMATION CONTACT section. For the full EPA public comment policy, information about CBI or multimedia submissions, and general guidance on making effective comments, please visit https://www.epa.gov/dockets/commenting-epa-dockets. If you need assistance in a language other than English or if you are a person with disabilities who needs a reasonable accommodation at no cost to you, please contact the person identified in the FOR FURTHER INFORMATION CONTACT section. FOR FURTHER INFORMATION CONTACT: John J. Kelly, Air Planning Office (AIR-2-1), EPA Region IX, 75 Hawthorne Street, San Francisco, CA 94105. By phone at (415) 947-4151, or by email at kelly.johnj@epa.gov. SUPPLEMENTARY INFORMATION: Throughout this document, “we,” “us,” and “our” refer to the EPA. Table of Contents I. Regulatory Context A. Ozone Standards, Area Designations, and SIPs B. The San Diego County Ozone Nonattainment Area C. Clean Air Act and Regulatory Requirements for 2008 and 2015 Ozone Nonattainment Area SIPs II. Submission From the State of California To Address Ozone Requirements in San Diego County A. Summary of State Submissions B. Clean Air Act Procedural Requirements for Adoption and Submission of SIP Revisions III. Evaluation of the 2020 San Diego County Ozone SIP A. Emissions Inventories B. Reasonably Available Control Measures Demonstration and Control Strategy C. Attainment Demonstration D. Rate of Progress Plan and Reasonable Further Progress Demonstration E. Transportation Control Strategies and Measures To Offset Emissions Increases From Vehicle Miles Traveled F. Contingency Measures G. Motor Vehicle Emissions Budgets for Transportation Conformity H. General Conformity Budgets I. Other Clean Air Act Requirements Applicable to Severe Ozone Nonattainment Areas IV. Environmental Justice Considerations V. Proposed Action VI. Statutory and Executive Order Reviews I. Regulatory Context A. Ozone Standards, Area Designations, and SIPs Ground-level ozone pollution is formed from the reaction of volatile organic compounds (VOC) and oxides of nitrogen (NO X ) in the presence of sunlight. 1 These two pollutants, referred to as ozone precursors, are emitted by many types of sources, including on- and off-road motor vehicles and engines, power plants and industrial facilities, and smaller area sources such as lawn and garden equipment and paints. 1 The State of California refers to reactive organic gases (ROG) in some of its ozone-related SIP submissions. As a practical matter, ROG and VOC refer to the same set of chemical constituents, and for the sake of simplicity, we refer to this set of gases as VOC in this proposed rule. Scientific evidence indicates that adverse public health effects occur following exposure to ozone, particularly in children and adults with lung disease. Breathing air containing ozone can reduce lung function and inflame airways, which can increase respiratory symptoms and aggravate asthma or other lung diseases. 2 2 “Fact Sheet—2008 Final Revisions to the National Ambient Air Quality Standards for Ozone,” dated March 2008. Under section 109 of the Clean Air Act (CAA or “the Act”), the EPA promulgates NAAQS for pervasive air pollutants, such as ozone, to protect public health and welfare. Under CAA section 110, following promulgation of a new or revised NAAQS, states are required to adopt and submit plans that provide for implementation, maintenance, and enforcement of the NAAQS (referred to as State Implementation Plans or SIPs). Under CAA section 107(d), the EPA is required to designate areas throughout the nation as either attaining or not attaining the NAAQS, and states with designated nonattainment areas are required to submit SIP revisions to, among other things, provide for attainment as expeditiously as practicable but not later than the applicable attainment dates. In 1979, the EPA established primary and secondary NAAQS for ozone at 0.12 parts per million (ppm) averaged over a 1-hour period (“1979 ozone NAAQS”). 3 In 1997, the EPA revised the primary and secondary standards for ozone in the ambient air to 0.08 ppm averaged over an 8-hour period (“1997 ozone NAAQS”). 4 3 44 FR 8202 (February 8, 1979). When the CAA was amended in 1990, each area of the country that was designated nonattainment for the 1979 ozone NAAQS, including the San Diego area, was classified by operation of law as nonattainment and classified as Marginal, Moderate, Serious, Severe, or Extreme depending on the severity of the area's air quality problem. The EPA redesignated the San Diego County area from Serious nonattainment to attainment for the 1979 ozone NAAQS, effective July 28, 2003. 68 FR 37976 (June 26, 2003). 4 62 FR 38856 (July 18, 1997). In 2004, the EPA designated areas of the country with respect to the 1997 ozone NAAQS. See 69 FR 23858 (April 30, 2004). The EPA redesignated the San Diego County area from Moderate nonattainment to attainment for the 1997 ozone NAAQS, effective July 5, 2013. 78 FR 33230 (June 4, 2013). In 2008, the EPA lowered the 8-hour ozone NAAQS to 0.075 ppm (“2008 ozone NAAQS”). 5 Then in 2015, the EPA further lowered the 8-hour ozone NAAQS to 0.070 ppm (“2015 ozone NAAQS”). 6 On December 31, 2020, the EPA finalized its most recent periodic review of the ozone NAAQS, retaining the form and level of the standards. 7 The EPA has revoked both the 1979 ozone NAAQS and the 1997 ozone NAAQS but not the 2008 ozone NAAQS. 8 5 73 FR 16436 (March 27, 2008). 6 80 FR 65292 (October 26, 2015). 7 85 FR 87256. The SIP revision that is the subject of this proposed action relates to the requirements for the 2008 and 2015 ozone standards. 8 40 CFR 50.9(b) and 40 CFR 50.10(c). In 2012, the EPA designated San Diego County as nonattainment for the 2008 ozone NAAQS and classified the area as “Marginal.” 9 Areas classified as Marginal must attain the NAAQS within three years of the effective date of the nonattainment designation. 10 Following this initial classification as Marginal, the EPA found in 2016 that the area did not attain the 2008 ozone standards by the Marginal attainment deadline of July 20, 2015. 11 As a result of our finding, the area was reclassified by operation of law to Moderate nonattainment. 12 Moderate nonattainment areas have six years to attain the standard. Following the Moderate attainment deadline of July 20, 2018, the EPA found that the area did not attain the 2008 ozone standards. 13 As a result of our finding, the area was reclassified by operation of law to Serious nonattainment, with a Serious attainment deadline of July 20, 2021, nine years after the effective date of designation as a nonattainment area for the 2008 ozone NAAQS. In response to a letter to the EPA dated January 8, 2021 from the California Air Resources Board (CARB), the EPA reclassified the area to Severe for the 2008 ozone NAAQS. 14 In the same letter, CARB requested that the EPA also reclassify the area as Severe for the 2015 ozone NAAQS. The EPA's initial designation for the San Diego County area for the 2015 ozone NAAQS was nonattainment, with a Moderate classification. 15 The San Diego County area is now classified as Severe for both the 2008 and the 2015 ozone NAAQS. 16 9 77 FR 30087 (May 21, 2012), effective July 20, 2012. 10 CAA section 181(a)(1); 40 CFR 51.1102 and 51.1103(a). 11 81 FR 26697 (May 4, 2016). 12 The State of California submitted the San Diego County area's 2016 Moderate ozone attainment plan and the 2016 Moderate ozone RACT demonstration to the EPA as a SIP revision on April 12, 2017. The State withdrew the 2016 Moderate ozone attainment plan by letter dated December 16, 2021, following submittal of the 2020 plan and the EPA's grant of the State's request to reclassify San Diego County to Severe for the 2008 ozone NAAQS. The EPA approved the 2016 Moderate ozone RACT demonstration at 85 FR 77996 (December 3, 2020), 87 FR 38665 (June 29, 2022) and 88 FR 2538 (January 17, 2023). 13 84 FR 44238 (August 23, 2019). 14 Letter dated January 8, 2021 from Richard Corey, Executive Officer, California Air Resources Board, to John Busterud, Regional Administrator, U.S. EPA Region IX; 86 FR 29522 (June 2, 2021), effective July 2, 2021. 15 83 FR 25776 (June 4, 2018). Severe areas must attain the standard as expeditiously as practicable, but not later than 15 years after the effective date of designation. For the 2008 ozone NAAQS, the Severe attainment deadline is July 20, 2027. However, note that for attainment modeling purposes we refer to the attainment year as 2026. For the 2015 ozone NAAQS, the Severe attainment deadline is August 3, 2033, with a 2032 attainment year. 16 86 FR 29522 (June 2, 2021), effective July 2, 2021. Designations of nonattainment for a given NAAQS trigger requirements under the CAA to prepare and submit SIP revisions. The SIP revision that is the subject of this proposed action addresses the Severe nonattainment area requirements that apply to the San Diego County area for the 2008 and the 2015 ozone NAAQS. Under California law, CARB is the state agency that is responsible for the adoption and submission to the EPA of California SIPs and SIP revisions, and it has broad authority to establish emissions standards and other requirements for mobile sources and certain area sources, such as consumer products. Local and regional air pollution control districts in California are responsible for the regulation of stationary sources and are generally responsible for the development of regional air quality management plans (“plans”). In the San Diego County area, the San Diego County Air Pollution Control District (SDCAPCD or “District”) develops and adopts plans to address CAA planning requirements applicable to that area. Such plans are then submitted to CARB for adoption and submittal to the EPA as revisions to the California SIP. B. The San Diego County Ozone Nonattainment Area The San Diego County area is located in the southwestern-most portion of the State of California, and its boundaries generally align with those of San Diego County. For a precise description of the geographic boundaries of the San Diego County area for both the 2008 and 2015 ozone NAAQS, see 40 CFR 81.305. Prior plans and state control measures developed by the District and CARB have produced significant emissions reductions over the years and improved air quality in the area. For instance, the 8-hour ozone design value for the San Diego County area decreased from 0.095 ppm to 0.079 ppm from 2002 to 2022, 17 despite increases in population and vehicular activity. 17 Three design value reports (EPA, Air Quality Design Value Report, July 12, 2011; San Diego 2008 Ozone Trends Report, U.S. EPA Air Quality System, May 8, 2023; and San Diego 2015 Ozone Trends Report, U.S. EPA Air Quality System, May 8, 2023), are included in the docket for this action. For the 2008 and 2015 ozone NAAQS, the design value at any given monitoring site is the 3-year average of the annual fourth highest daily maximum 8-hour average ambient air quality ozone concentration. The maximum design value among the various ozone monitoring sites is the design value for the area. Under certain weather conditions, the San Diego County area is downwind from the Los Angeles-South Coast Air Basin (“South Coast”) and, under certain other weather conditions, from Mexico, and is subject to transport of ozone from those areas. The South Coast is regulated by the South Coast Air Quality Management District (SCAQMD). The 2020 Plan describes ozone transport from these areas as follows: . . . air pollution from both regions significantly contribute to ozone levels in the San Diego region under certain weather conditions. This impact is acknowledged in State documentation and regulation. Importantly . . . SCAQMD has implemented effective emissions control programs, resulting in a trend of emission reductions and air quality improvements in the South Coast region. Though the region is designated as an Extreme Nonattainment Area for the 2008 and 2015 ozone NAAQS, SCAQMD predicts continued ozone reductions through at least 2031 as shown in their SIP for the 2008 ozone NAAQS. In turn, air pollution transported to San Diego County is expected to decrease as a result of their actions. 18 18 2020 Plan, p. 13. Because of the transport from the South Coast into the San Diego County area, continued progress in the South Coast towards meeting the 2008 and 2015 ozone NAAQS is expected to help the San Diego County area attain these ozone NAAQS. C. Clean Air Act and Regulatory Requirements for 2008 and 2015 Ozone Nonattainment Area SIPs States must implement the 2008 and 2015 ozone NAAQS under title I, part D of the CAA, including sections 171-179B of subpart 1 (“Nonattainment Areas in General”) and sections 181-185 of subpart 2 (“Additional Provisions for Ozone Nonattainment Areas”). To assist states in developing effective plans to address ozone nonattainment problems, in 2015, the EPA issued a SIP Requirements Rule (SRR) that addresses implementation of various aspects of the 2008 ozone NAAQS (“2008 Ozone SRR”), including attainment dates, requirements for emissions inventories, attainment demonstrations, and reasonable further progress (RFP) demonstrations, among other SIP elements. The 2008 Ozone SRR also addresses the transition from the 1997 ozone NAAQS to the 2008 ozone NAAQS and associated anti-backsliding requirements. 19 In 2018, the EPA also issued an SRR for the 2015 ozone NAAQS (“2015 Ozone SRR”) that addresses implementation of the 2015 standards. 20 The regulatory requirements of the 2008 Ozone SRR are codified at 40 CFR part 51, subpart AA; those for the 2015 Ozone SRR are codified in 40 CFR part 51, subpart CC. We discuss the CAA and regulatory planning requirements for the elements of 2008 and 2015 ozone plans relevant to this proposed action in more detail in Section III of this document. 19 80 FR 12264 (March 6, 2015). Anti-backsliding requirements are the provisions applicable to revoked NAAQS (including the 1979 1-hour ozone NAAQS and the 1997 ozone NAAQS). 20 83 FR 62998 (December 6, 2018). II. Submission From the State of California To Address Ozone Requirements in San Diego County A. Summary of State Submissions 1. SDCAPCD's 2020 Attainment Plan On January 12, 2021, CARB submitted the 2020 Plan to the EPA as a revision to the California SIP. 21 The 2020 Plan addresses many of the nonattainment area requirements for the San Diego County area for both the 2008 and the 2015 8-hour ozone NAAQS. In this document, we are proposing action on the 2020 Plan that addresses both the 2008 and 2015 8-hour ozone NAAQS for the San Diego County area. 21 Letter (with enclosures) dated January 8, 2021, from Richard Corey, Executive Officer, CARB, to John Busterud, Regional Administrator, EPA Region IX (submitted electronically January 12, 2021). The 2020 Plan SIP submittal includes the various sections and attachments of the plan, plus the District's resolution of approval for the plan (District Resolution 20-166) and CARB's resolution of adoption of the plan as a revision to the California SIP (CARB Resolution 20-29). 22 The 2020 Plan includes a District commitment to achieve additional emissions reductions beyond those expected to occur from already-implemented control measures and relies on a similar commitment by CARB. More specifically, the 2020 Plan includes a commitment by the District to achieve an additional 1.7 tons per day (tpd) reduction in NO X by 2032 23 and relies on CARB's commitment to achieve aggregate emissions reductions in San Diego County of 4 tpd of NO X by 2032. 24 Both commitments are part of the 2020 Plan's attainment demonstration for the 2015 ozone NAAQS. With respect to both the 2008 and the 2015 ozone NAAQS, the 2020 Plan addresses the CAA requirements for emissions inventories, air quality modeling demonstrating attainment, reasonably available control measures (RACM), RFP, transportation control strategies and measures, new source review (NSR), contingency measures for failure to make RFP or to timely attain the relevant standards, and motor vehicle inspection and maintenance (I/M) programs (also referred to as “smog check” programs), among other requirements. The 2020 Plan also addresses the emissions statement requirement, and in separate action, the EPA approved the emissions statement portion of the 2020 Plan as meeting the applicable requirements for emissions statements for the 2008 and 2015 ozone NAAQS. 25 22 SDCAPCD Board Resolution 20-166, October 14, 2020; CARB Board Resolution 20-29, Proposed San Diego 8-Hour Ozone State Implementation Plan Submittal, November 19, 2020 (“CARB Board Resolution 20-29”). 23 2020 Plan, at 58, 81-82. 24 CARB Board Resolution 20-29, at 6. 25 87 FR 45657 (July 29, 2022). The 2020 Plan is organized into an executive summary, five sections, and attachments lettered A through Q. Section 1, “Introduction and Overview,” introduces the 2020 Plan, including its purpose, the two ozone NAAQS it addresses, current air quality in the area in comparison with those NAAQS, historical air quality progress in San Diego County, and the District's approach to air quality planning. Section 2, “General Attainment Plan Requirements,” addresses CAA requirements that apply to the area as nonattainment for both the 2008 and the 2015 ozone NAAQS. Section 3, “2008 Eight Hour Ozone NAAQS Attainment Plan Requirements,” addresses CAA requirements that apply to the area as nonattainment specifically for the 2008 ozone NAAQS, including anti-backsliding requirements for the revoked 1979 and 1997 ozone standards. Section 4, “2015 Eight Hour Ozone NAAQS Attainment Plan Requirements,” addresses CAA requirements that apply to the area as nonattainment specifically for the 2015 ozone NAAQS, including anti-backsliding requirements for revoked standards. Section 5, “Conclusions,” presents the District's conclusions regarding whether the 2020 Plan meets applicable Clean Air Act requirements. The 2020 Plan also includes technical attachments: • Attachment A (“Emissions Inventories and Documentation for Baseline, RFP, and Attainment Years”) presents tables, analysis, and documentation for the emissions inventories included in the plan. • Attachment B (“Planned Military Projects Subject to General Conformity”) contains annual data compiled by the United States Marine Corps (USMC) and Department of the Navy (DoN) for emissions changes resulting from USMC and DoN projects out to year 2037, for the purpose of demonstrating general conformity for USMC and DoN facilities in the area. • Attachment C (“Planned San Diego International Airport Projects Subject to General Conformity”) is a report that provides an emissions inventory for the San Diego International Airport, for the purpose of demonstrating general conformity for the airport. • Attachment D (“CARB Control Measures, 1985 to 2019”) is a listing of CARB control measures from 1985 to 2019. • Attachment E (“CARB Analyses of Key Mobile Source Regulations and Programs Providing Emission Reductions”) describes CARB's mobile source regulations and programs that provide emissions reductions in the San Diego County area. • Attachment F (“Pre-Baseline Banked Emission Reduction Credits”) describes emission reduction credits that were banked before the baseline year. • Attachment G (“Analyses of Potential Additional Stationary Source Control Measures”) provides the District's analysis of the feasibility of additional stationary source control measures that could be pursued in the area. • Attachment H (“Implementation Status of Transportation Control Measures”) provides the implementation status of transportation control measures by the San Diego Association of Governments (SANDAG) and other transportation agencies. • Attachment I (“CARB Analyses of Potential Additional Mobile Source and Consumer Products Control Measures”) analyzes the potential for further mobile source and consumer products controls in the area. • Attachment J (“Calculation of Cumulative Potential Emission Reductions for Possible Reasonably Available Control Measures (RACM)”) calculates the cumulative potential emissions reductions in the area in support of the plan's RACM demonstration. • Attachment K (“Modeling Protocol & Attainment Demonstration for the 2020 San Diego Ozone SIP”) provides the modeling protocol and attainment demonstration for the San Diego County area as Severe nonattainment for both the 2008 and the 2015 ozone NAAQS. • Attachment L (“Modeling Emission Inventory for the Ozone State Implementation Plan in San Diego County”) describes the modeled or “gridded” emissions inventories for the area, in support of the area's two modeled attainment demonstrations. • Attachment M (“Weight of Evidence Demonstration for San Diego County”) provides a weight-of-evidence demonstration for the area, in support of the area's modeled attainment demonstrations. • Attachment N (“VMT Offset Demonstration for San Diego County”) provides the area's VMT offset demonstration. • Attachment O (“Contingency Measures for San Diego County”) represents the District's assessment of compliance with the contingency measure requirements for the area. • Attachment P (“Federal Clean Air Act Requirements and References in Attainment Plan”) provides a summary of CAA requirements that apply to the area with specific citations to locations in the plan that address those requirements. • Attachment Q (“Endnotes”) contains the text of all endnotes found in the plan. Attainment of the 2008 and the 2015 ozone NAAQS in the San Diego County area is dependent on emissions reductions occurring in the adjacent South Coast nonattainment area. The 2016 South Coast Ozone SIP documents baseline emissions reductions from already-adopted control measures and provides for new emissions reductions to be achieved through fulfillment of SCAQMD and CARB commitments for further reductions, and through new technology measures. 26 More specifically, as discussed in Section III.D, “Attainment Demonstration,” of the EPA's proposed approval of the 2016 South Coast Ozone SIP, 27 the ozone attainment demonstrations for South Coast for the 1997 and 2008 ozone NAAQS include emissions reduction commitments made by the SCAQMD in the 2016 AQMP and by CARB in the “Revised Proposed 2016 State Strategy for the State Implementation Plan” (“2016 State Strategy”). 26 84 FR 28132 (June 17, 2019), at 28134-28134, tables 10 and 11. The EPA finalized its approval of the 2016 South Coast Ozone SIP at 84 FR 52005 (October 1, 2019). 27 84 FR 28132, 28143-28157 (June 17, 2019), The 2016 State Strategy focuses on two areas: the South Coast and the San Joaquin Valley. Although it did not include specific emissions reduction commitments for San Diego County, CARB states that, “[s]hould additional areas require emission reductions to meet the current ozone and PM 2.5 standards, ARB will quantify area and year specific reductions as part of individual attainment plans.” 28 The 2020 Plan for the 2015 ozone NAAQS relies on CARB's commitment to achieve 4 tpd of NO X emissions reductions in 2032 from mobile sources to demonstrate attainment of this standard in San Diego County. 29 28 2016 State Strategy, 35. 29 CARB Review of the 2020 Plan for Attaining the National Ambient Air Quality Standards for Ozone in San Diego County, Release Date: October 16, 2020, at 11; CARB Board Resolution 20-29, at 6. 2. Smog Check Certification On April 26, 2023, CARB submitted the “California Smog Check Performance Standard Modeling and Program Certification for the 70 Parts Per Billion (ppb) 8-Hour Ozone Standard” (“Smog Check Certification”) to supplement the motor vehicle I/M portion of the 2020 Plan. 30 The Smog Check Certification includes CARB's evaluation of the California Smog Check program for compliance with the applicable I/M performance standard as defined in EPA's regulations for certain nonattainment areas for the 2008 and 2015 ozone NAAQS, including San Diego County. 30 Letter (with enclosures) dated April 26, 2023, from Steven S. Cliff, Ph.D., Executive Officer, CARB, to Martha Guzman, Regional Administrator, EPA Region IX (submitted electronically April 26, 2023). CARB's SIP submittal package for the Smog Check Certification includes CARB Resolution 23-9, through which CARB adopted the Smog Check Certification as part of the California SIP, 31 public notice of CARB's hearing on the proposed SIP revision, public comments and responses, and MOVES 32 input and output data sheets. In this document, we are proposing action on the San Diego County portion of the Smog Check Certification as a supplement to the vehicle I/M portion of the 2020 Plan. 31 CARB Board Resolution 23-9, March 23, 2023. 32 MOVES is the acronym for the EPA's Motor Vehicle Emission Simulator model. B. Clean Air Act Procedural Requirements for Adoption and Submission of SIP Revisions CAA sections 110(a) and 110(l) require a state to provide reasonable public notice and opportunity for public hearing prior to the adoption and submission of a SIP or SIP revision. To meet this requirement, every SIP submittal should include evidence that adequate public notice was given and an opportunity to submit written comments and request a public hearing was provided consistent with the EPA's implementing regulations in 40 CFR 51.102. Both the District and CARB have satisfied the applicable statutory and regulatory requirements for reasonable public notice and hearing prior to the adoption and submittal of the 2020 Plan. The District held two public webinars, one in July and another in August, 2020, and held a hearing on October 14, 2020, to discuss the plan and solicit public input. 33 On September 14, 2020, the District published a notice in a local newspaper of the public hearing to be held on October 14, 2020, to consider approval of the 2020 Plan. 34 On October 14, 2020, the District held the public hearing, and on that same date, through Resolution 20-166, the District board approved the 2020 Plan and directed the Air Pollution Control Officer to forward its resolution and the 2020 Plan to CARB for submittal to the EPA for inclusion in the California SIP. 33 Letter dated October 20, 2020,from Robert Reider, Interim Director, SDCAPCD, to Richard Corey, CARB Executive Officer. See the letter's response to comments document regarding the two webinars and its “Minute Order” document regarding the public hearing. 34 Id. See the October 20, 2020 letter's proof of publication document regarding public notice for the October 14, 2020 public hearing. Upon receipt of the 2020 Plan from the District, CARB also provided public notice and opportunity for public comment on the plan. On October 16, 2020, CARB released for public review its staff report for the 2020 Plan (“CARB Staff Report”) 35 and published a notice of public meeting to be held on November 19, 2020, to consider adoption of the 2020 Plan as a revision to the California SIP. 36 On November 19, 2020, CARB held the hearing and adopted the 2020 Plan as a revision to the California SIP and directed the Executive Officer to submit the 2020 Plan to the EPA for approval into the California SIP. 37 On January 12, 2021, the Executive Officer of CARB submitted the 2020 Plan to the EPA. Six months after submittal, on July 12, 2021, the 2020 Plan became complete by operation of law. 38 35 CARB Review of the 2020 Plan for Attaining the National Ambient Air Quality Standards for Ozone in San Diego County, Release Date: October 16, 2020. 36 Notice of Public Meeting to Consider Approval of the Proposed San Diego 8-Hour Ozone State Implementation Plan Submittal, signed by Richard Corey, Executive Officer, CARB, October 16, 2020. 37 CARB Resolution 20-29, 6. 38 CAA section 110(k)(1)(B). CARB has also satisfied the applicable statutory and regulatory requirements for reasonable public notice and hearing prior to the adoption and submittal of the Smog Check Certification. On February 10, 2023, CARB released for public review the draft Smog Check Certification and published a notice of public meeting to be held on March 23, 2023, to consider adoption of the Smog Check Certification as a revision to the California SIP. 39 On March 23, 2023, CARB held the hearing and adopted the Smog Check Certification as a revision to the California SIP and directed the Executive Officer to submit the Smog Check Certification to the EPA for approval into the California SIP. 40 On April 26, 2023, the Executive Officer of CARB submitted the Smog Check Certification to the EPA. 39 Notice of Public Meeting to Consider the Proposed California Smog Check Performance Standard Modeling and Program Certification for the 70 parts per billion 8-hour Ozone Standard, signed by Steven S. Cliff, Ph.D., Executive Officer, CARB, February 10, 2023. 40 CARB Resolution 23-9, 6. Based on information provided in the SIP revisions submitted on January 12, 2021 and April 26, 2023, and summarized in Section II.A this document, the EPA has determined that all hearings were properly noticed and that a reasonable opportunity to submit written comments was provided. Therefore, we find that the submittal of the 2020 Plan and the Smog Check Certification meets the procedural requirements for public notice and hearing in CAA sections 110(a) and 110(l) and 40 CFR 51.102. III. Evaluation of the 2020 San Diego County Ozone SIP A. Emissions Inventories 1. Statutory and Regulatory Requirements CAA sections 172(c)(3) and 182(a)(1) require states to submit for each ozone nonattainment area a “base year inventory” that is a comprehensive, accurate, current inventory of actual emissions from all sources of the relevant pollutant or pollutants in the area. In addition, the 2008 Ozone SRR and the 2015 Ozone SRR require that the inventory year be selected consistent with the baseline year for the RFP demonstration, which is the most recent calendar year for which a complete triennial inventory is required to be submitted to the EPA under the Air Emissions Reporting Requirements (AERR) at the time of designation for the ozone NAAQS. 41 For the 2008 ozone NAAQS, the baseline year for the RFP demonstration is 2011, and for the 2015 ozone NAAQS, the base year for the RFP demonstration is 2017. 41 2008 Ozone SRR at 40 CFR 51.1115(a) and 40 CFR 51.1110(b), 2015 Ozone SRR at 40 CFR 51.1315(a) and 40 CFR 51.1310(b), and the Air Emissions Reporting Requirements at 40 CFR part 51, subpart A. The EPA has issued guidance on the development of base year and future year emissions inventories for 8-hour ozone and other pollutants. 42 Emissions inventories for ozone must include emissions of VOC and NO X and represent emissions for a typical ozone season weekday. 43 States should include documentation explaining how the emissions data were calculated. In estimating mobile source emissions, states should use the latest emissions models and planning assumptions available at the time the SIP is developed. 44 42 “Emissions Inventory Guidance for Implementation of Ozone and Particulate Matter National Ambient Air Quality Standards (NAAQS) and Regional Haze Regulations,” EPA-454/B-17-002, May 2017, available in the docket for this action and at https://www.epa.gov/air-emissions-inventories/air-emissions-inventory-guidance-implementation-ozone-and-particulate . 43 For 2008 ozone, 40 CFR 51.1115(a) and (c), and 40 CFR 51.1100(bb) and (cc). For 2015 ozone, 40 CFR 51.1315(a) and (c), and 40 CFR 51.1300(p) and (q). 44 80 FR 12264, 12290 (March 6, 2015); 83 FR 62998, 63022 (December 6, 2018). Future baseline emissions inventories must reflect the most recent population, employment, travel, and congestion estimates for the area. In this context, “baseline” emissions inventories refer to emissions estimates for a given year and area that reflect rules and regulations and other measures that are already adopted. Future baseline emissions inventories are necessary to show the projected effectiveness of SIP control measures. Both the base year and future year inventories are necessary for photochemical modeling to demonstrate attainment. 2. Summary of State's Submission The 2020 Plan includes three sets of base year and future year average summer day baseline inventories for NO X and VOC for the San Diego County area, for both the 2008 and 2015 ozone NAAQS. 45 One set of base year and future year baseline emissions inventories reflects emissions within the San Diego County area and includes marine emissions out to 100 nautical miles (NM) from the coast. A second set of emissions inventories adds emissions from the South Coast Air Basin to those generated within the San Diego County area (plus marine emissions out to 100 NM from the coast) to produce combined inventories. A third set of emissions inventories reflects San Diego County area emissions including marine emissions but only out to three NM from the coast. All three sets of inventories include the years 2011, 2017, 2020, 2023, 2026, 2029 and 2032. 45 2020 Plan, Attachment A. Documentation for the inventories is found in Sections 3 and 4 of the 2020 Plan, addressing the 2008 and 2015 ozone NAAQS, respectively, as well as in the Plan's Attachment A. Because ozone levels in the area are typically highest during the summer months, the inventories provided in the 2020 Plan represent average summer day emissions from May through October. The inventories in the 2020 Plan reflect District rules adopted through the end of calendar year 2019 and CARB rules adopted through the end of calendar year 2017. For estimating on-road motor vehicle emissions, these inventories use EMFAC2017, the EPA-approved version of California's mobile source emissions model available at the time the 2020 Plan was developed. 46 46 EMFAC is short for EMission FACtor. The EPA announced the availability of the EMFAC2017 model for use in state implementation plan development and transportation conformity in California on August 15, 2019. 84 FR 41717. The EPA's approval of the EMFAC2017 emissions model for SIP and conformity purposes was effective on the date of publication of the notice in the Federal Register . The VOC and NO X emissions estimates are grouped into two general categories, stationary sources and mobile sources. Stationary sources are further divided into “point” and “area” sources. Point sources typically refer to stationary sources that are permitted facilities and have one or more identified and fixed pieces of equipment and emissions points. Area sources consist of widespread and numerous smaller emissions sources, such as consumer products, fireplaces and agricultural burning. 47 The mobile sources category is divided into two major subcategories, “on-road” and “off-road” mobile sources. On-road mobile sources include light-duty automobiles, light-, medium-, and heavy-duty trucks, and motorcycles. Off-road mobile sources include aircraft, locomotives, construction equipment, mobile equipment, and recreational vehicles. 47 2020 Plan, p. A-30. Point source (also referred to as “stationary source”) emissions for the 2011 and 2017 base year emissions inventories are calculated using reported data from facilities using the District's annual emissions reporting program, which applies under District Rule 19.3 to stationary sources in the San Diego County area that emit 25 tons per year (tpy) or more of VOC or NO X . Area sources include smaller emissions sources distributed across the nonattainment area. CARB and the District estimate emissions for numerous area source categories using established inventory methods, including publicly available emissions factors and activity information. Specific estimates are included in the 2020 Plan for area source categories: consumer products, architectural coatings and related process solvent use, pesticides and fertilizers, asphalt paving and roofing, residential fuel combustion, farming operations, fires, managed burning and disposal, and cooking. On-road emissions inventories in the 2020 Plan are calculated using CARB's EMFAC2017 model and the travel activity data provided by SANDAG in SANDAG's 2018 adopted Regional Transportation Improvement Program. 48 CARB provided emissions inventories for off-road equipment, including construction and mining equipment, industrial and commercial equipment, lawn and garden equipment, agricultural equipment, ocean-going vessels, commercial harbor craft, locomotives, cargo handling equipment, pleasure craft, and recreational vehicles. CARB used several models to estimate emissions for off-road equipment categories. 49 Aircraft emissions inventories are developed in conjunction with the airports in the region. In particular, an emissions analysis was included in the 2020 Plan for the San Diego International Airport. 50 48 Id. at A-35. SANDAG is the metropolitan planning organization (MPO) for San Diego County. 49 Id. at A-36. 50 Id., Attachment C, “Planned San Diego International Airport Projects Subject to General Conformity.” The 2020 Plan distinguishes between emissions sources within San Diego County, which includes coastal emissions (including marine vessel emissions) within three NM of the coastline, and emissions sources operating outside the county but within 100 NM of the coastline. The base year emissions inventory reflects only those emissions sources that operate within the nonattainment area ( i.e., within three NM of the coastline), but offshore emissions sources affect ozone concentrations in the nonattainment area and thus are included in the emissions inventories used for the attainment demonstrations in the 2020 Plan. The calendar year 2017 is the base year in the 2020 Plan for both the 2008 and 2015 ozone NAAQS because 2017 the most recent calendar year for which a complete triennial inventory was required to be submitted to the EPA under the provisions of 40 CFR part 51, subpart A at the time of plan development. The 2020 Plan includes an emissions inventory for an earlier year, i.e., calendar year 2011, because that year is the RFP baseline year for the 2008 ozone NAAQS. The 2017 base year inventory was used to forecast all future years for area and mobile sources and to “backcast” such sources for 2011. 51 51 Id. at Q-2, footnote 29. To develop the 2011 inventory, CARB relied on actual emissions reported from industrial point sources for 2011 and backcast emissions from 2017 for smaller stationary and certain area sources. 52 Area source emissions from pesticide were developed by CARB based on actual emissions reported for 2011, while those from agricultural burning were developed by CARB based on actual emissions reported for 2008 that were “grown” (that is, projected forward from 2008, based on estimated changes in agricultural burning) to 2011. CARB produced 2011 on-road emissions estimates using EMFAC2017. Non-road emissions were either backcast from 2017 (commercial aircraft and military ocean-going vessels) or were estimated using CARB's OFFROAD2007 model. 53 52 Id. 53 Email dated March 21, 2023, from Nick Cormier, SDCAPCD to John J. Kelly, EPA, Subject: “FW: 2011 emission inventory in SD's 2020 ozone plan.” For the 2020 Plan, CARB used the California Emission Projection Analysis Model (CEPAM), 2019 SIP Baseline Emission Projections, Version 1.00 to develop future year emissions forecasts ( i.e., 2020, 2023, 2026, 2029 and 2032). 54 In doing so, CARB reviewed the growth and control factors for each category and relevant year along with the resulting emissions projections. 55 CARB compared year-to-year trends to similar and past datasets to ensure general consistency, checked emissions for specific categories to confirm they reflect the anticipated effects of applicable control measures, and verified mobile source categories with CARB mobile source staff for consistency with the on-road and off-road emission models. 56 54 2020 Plan, Attachment A, Section A.8. 55 Id. 56 Id. In developing the 2020 Plan, the District worked with the Department of the Navy and the United States Marine Corps to identify specific growth increments from future anticipated actions to include in the baseline emissions forecasts for use by the military to comply with the applicable general conformity regulations. The District then coordinated with CARB to include the growth increments or “budgets” in the applicable source categories in the CEPAM model used by CARB to develop the future year emissions inventories. More specifically, the CEPAM model runs used for the future year emissions estimates in the 2020 Plan reflect a military growth increment of 1.08 tpd of VOC and 8.34 tpd of NO X for all future years addressed in the plan. 57 Similarly, the District worked with the San Diego County Regional Airport Authority to identify a growth increment for future anticipated actions at San Diego International Airport (SDIA) for use in connection with the general conformity regulations. The growth increment for SDIA for all future year emissions estimates in the 2020 Plan is 0.141 tpd of VOC and 1.756 tpd for NO X . 58 Section III.H of this document provides further information on the military and SDIA growth increments reflected in the 2020 Plan. 57 2020 Plan, Section 2.1.3.1 and Attachment B. 58 Id., Section 2.1.3.2 and Attachment C. The future year emissions estimates in the 2020 Plan include two additional specific adjustments—one to account for pre-base year emissions reduction credits (ERCs) and one to account for the EPA's rescission, in a final action referred to as “SAFE 1,” of a waiver of preemption of CARB's light-duty vehicle zero emission vehicle (ZEV) sales mandate and greenhouse gas (GHG) standards. 59 59 “The Safer Affordable Fuel-Efficient (SAFE) Vehicles Rule Part One: One National Program” (SAFE 1), 84 FR 51310 (September 27, 2019). Under the EPA's SIP regulations for nonattainment new source review (NSR) programs, a state may allow new major stationary sources or major modifications to use as offsets ERCs that were generated through shutdown or curtailed emissions units occuring before the base year of an attainment plan. However, to use such ERCs, the projected emissions inventories used to develop the RFP and attainment demonstration must explicitly include the emissions from such previously shutdown or curtailed emissions units. 60 The District has elected to provide for use of pre-base year ERCs as offsets by explicitly including such ERCs in the future year emissions estimates in the 2020 Plan. The ERC set-aside in the 2020 Plan amounts to 0.71 tpd of VOC and 0.56 tpd of NO X . 61 60 40 CFR part 51, Appendix S, section IV.C.5. 61 2020 Plan, section 2.1.3.3 and Attachment F. The “EMFAC2017 Adjustment Factors” refers to adjustment factors that CARB developed for EMFAC2017 to account for the EPA's SAFE 1 final action that, among other things, withdrew the EPA's waiver of preemption for CARB's Advanced Clean Car (ACC) regulation as it pertained to CARB's ZEV sales mandate and GHG standards. 62 EMFAC2017 reflected emissions reductions that were estimated to be achieved through implementation of the ACC regulation, including the ZEV sales mandate. In response to the EPA's SAFE 1 action, CARB developed correction factors to be used to account for the foregone emissions reductions (EMFAC2017 Adjustment Factors). 63 In 2020, the EPA concurred on the use of CARB's EMFAC2017 Adjustment Factors for the purposes of SIP development in California, 64 and the 2020 Plan takes them into account as an adjustment to the EMFAC2017-derived motor vehicle emissions estimates included in the future year emissions inventories. For the 2020 Plan, the EMFAC2017 Adjustment Factor is generally 0.1 tpd or less for VOC and NO X in all future years expected to be affected by the SAFE 1 action. 62 The EPA issued the ACC waiver on January 9, 2013 (78 FR 2112). 63 Letter and enclosures dated March 5, 2020 from Steven S. Cliff, Ph.D., Deputy Executive Officer, CARB, to Elizabeth Adams, Director, Air and Radiation Division, EPA Region IX. 64 Letter dated March 12, 2020, from Elizabeth J. Adams, Director, Air and Radiation Division, EPA Region IX, to Steven S. Cliff, Ph.D., Deputy Executive Officer, CARB. Table 1 of this document provides a summary of the baseline emissions inventories for the base year and future years in tpd (average summer day) for VOC and NO X for the 2008 ozone NAAQS. 65 The inventories summarized in Table 1 distinguish between emissions generated within the nonattainment area and emissions that are generated offshore between three NM and 100 NM from the coastline of San Diego County. Table 1 also shows the adjustments made to account for ERCs and the EMFAC2017 Adjustment Factors. Table 2 of this document provides the same type of summary information as Table 1, but presents the base year and future years that are relevant for the 2015 ozone NAAQS. 65 Tables 1 and 2 summarize anthropogenic emissions sources only, which is consistent with the EPA's “Emissions Inventory Guidance for Implementation of Ozone and Particulate Matter National Ambient Air Quality Standards (NAAQS) and Regional Haze Regulations” (May 2017). Anthropogenic emissions sources are distinguishable from natural sources, which include biogenic, geogenic and wildfire emissions sources. Both anthropogenic and natural sources of emissions are, however, included in emissions inventories used for attainment demonstration modeling purposes. Based on the emissions inventory for 2017, stationary, area, and mobile sources (on-road and off-road) contribute roughly equally to county-wide VOC emissions, whereas mobile sources (on-road and off-road) are the predominant sources of NO X emissions. The inventory for 2017 also shows the magnitude of marine offshore (3 NM to 100 NM) emissions sources relative to those within the nonattainment area. A comparison of the base years with the future years shows the significant decrease that is expected to be achieved through CARB's regulations for new on-road and off-road mobile sources together with vehicle turnover ( i.e., the rate of replacement of older, more polluting models with new models manufactured to meet tighter emissions standards). For a more detailed discussion of the methodologies used to develop the inventories, see Attachment A of the 2020 Plan. Table 1—San Diego County Base Year and Future Year Baseline Emissions Inventories for the 2008 Ozone NAAQS [Summer planning inventory, tpd] 2011 NO X VOC 2017 NO X VOC 2020 NO X VOC 2023 NO X VOC 2026 NO X VOC Stationary Sources 4.4 27.4 4.1 27.6 4.0 26.9 3.9 26.3 4.0 26.3 Area Sources 1.9 36.8 1.7 33.6 1.5 34.3 1.4 34.8 1.2 35.2 On-Road Mobile Sources 71.2 34.4 37.7 20.5 28.5 16.5 19.7 13.8 17.5 12.3 Off-Road Mobile Sources 33.2 38.0 33.5 31.1 32.6 28.5 31.2 26.7 30.3 25.2 Emission Reduction Credits adjustment 0.6 0.7 0.6 0.7 0.6 0.7 EMFAC2017 Adjustment Factor <0.1 0.1 <0.1 <0.1 Total—San Diego County Nonattainment Area 110.7 136.6 77.0 112.9 67.1 107.0 56.8 102.4 53.6 99.7 Marine Emissions (3 NM-100 NM) 15.8 0.8 17.5 1.0 17.5 1.0 18.1 1.0 18.6 1.1 Total—Nonattainment Area plus Marine Emissions (3 NM-100 NM) 126.5 137.5 94.5 113.8 84.7 108.0 74.8 103.4 72.2 100.8 Source: 2020 Plan, Attachment A, Tables A-1 and A-3. The sum of the emissions values may not equal the total due to rounding of the numbers. Table 2—San Diego County Base Year and Future Year Baseline Emissions Inventories for the 2015 Ozone NAAQS [summer planning inventory, (tpd)] 2017 NO X VOC 2023 NO X VOC 2026 NO X VOC 2029 NO X VOC 2032 NO X VOC Stationary Sources 4.1 27.6 3.9 26.3 4.0 26.3 4.0 26.6 4.1 27.2 Area Sources 1.7 33.6 1.4 34.8 1.2 35.2 1.0 35.6 1.0 36.1 On-Road Mobile Sources 37.7 20.5 19.7 13.8 17.5 12.3 16.0 11.1 15.1 10.0 Off-Road Mobile Sources 33.5 31.1 31.2 26.7 30.3 25.2 29.7 24.2 28.9 23.2 Emission Reduction Credits adjustment 0.6 0.7 0.6 0.7 0.6 0.7 0.6 0.7 EMFAC2017 Adjustment Factor <0.1 0.1 <0.1 <0.1 <0.1 <0.1 <0.1 0.1 Total—San Diego County Nonattainment Area 77.0 112.9 56.8 102.4 53.6 99.7 51.3 98.2 49.7 97.2 Marine Emissions (3 NM-100 NM) 17.5 1.0 18.1 1.0 18.6 1.1 19.0 1.0 19.3 1.1 Total—Nonattainment Area plus Marine Emissions (3 NM-100 NM) 94.5 113.8 74.8 103.4 72.2 100.8 70.0 99.3 69.0 98.3 Source: 2020 Plan, Attachment A, Tables A-1 and A-3. The sum of the emissions values may not equal the total due to rounding of the numbers. 3. The EPA's Review of the State's Submission The 2020 Plan refers to year 2017 as the base year inventory for both the 2008 and 2015 ozone NAAQS but also includes an inventory of actual emissions in calendar year 2011, which we have reviewed for the purpose of evaluating compliance with the base year emissions inventory SIP requirement for the 2008 ozone NAAQS. Year 2017 is the appropriate base year for the emissions inventory SIP requirement for the 2015 ozone NAAQS. We have reviewed the 2011 and 2017 base year emissions inventories in the 2020 Plan and the inventory methodologies used by the District and CARB for consistency with CAA requirements and EPA guidance. First, we find that the 2011 and 2017 inventories include estimates for VOC and NO X for a typical ozone season weekday, and that CARB has provided adequate documentation explaining how the emissions are calculated. Second, we find that the 2011 and 2017 base year emissions inventories in the 2020 Plan reflect appropriate emissions models and methodologies, and, therefore, represent comprehensive, accurate, and current inventories of actual emissions during those years in the San Diego County area. Therefore, the EPA is proposing to approve the 2011 and 2017 emissions inventories in the 2020 Plan as meeting the requirements for base year inventories for 2008 and 2015 ozone set forth in CAA sections 172(c)(3) and 182(a)(1), and 40 CFR 51.1115 and 40 CFR 51.1315. In addition, although the requirement for a base year emissions inventory applies to the nonattainment area, we find that the District's estimates of marine emissions out to 100 NM ( i.e., beyond the nonattainment area boundary that extends three NM offshore) are reasonable and appropriate to include in the 2020 Plan given that such emissions must be accounted for in the ozone attainment demonstrations for this nonattainment area. With respect to the future year emissions baseline projections, we have reviewed the growth and control factors and find them acceptable and conclude that the future baseline emissions projections in the 2020 Plan reflect appropriate calculation methods and the latest planning assumptions. We have also reviewed the documentation concerning the growth increments for the military and for SDIA and the documentation for the ERCs and find that they are appropriately accounted for in the future year baseline emissions inventories or, in the case of the ERCs, as an off-model adjustment to the inventories. 66 With respect to the EMFAC2017 Adjustment Factors, we note that, since adoption of the 2020 Plan, the EPA has rescinded SAFE 1 (the withdrawal of the waiver of CARB's ZEV sales mandate and GHG standards), 67 which calls into question the use of the EMFAC2017 Adjustment Factor, as it may affect projections, particularly over the long term. However, as shown in Tables 1 and 2, the EMFAC2017 Adjustment Factor adjustment in the future year emissions inventories is insignificant (0.1 tpd or less for both VOC and NO X ), and thus the change in circumstances regarding the status of CARB's ZEV sales mandate does not affect the emissions projections used for the RFP and attainment demonstrations in the 2020 Plan. 66 See Section III.H of this document for our full evaluation, and proposed approval, of the growth increments for the military and SDIA. 67 87 FR 14332 (March 14, 2022). Also, as a general matter, the EPA will approve a SIP revision that takes emissions reduction credit for a control measure only where the EPA has approved the measure as part of the SIP. Thus, to take credit for the emissions reductions from District rules for stationary sources and CARB rules for mobile sources, the related rules must be approved by the EPA into the SIP. 68 The EPA performed a review of District rules relied upon in developing the future baseline emissions inventories for the 2020 Plan. 69 Based on our review, we find that, with only one exception that does not implicate the RFP or attainment demonstrations of the 2020 Plan, 70 District rules relied upon in developing the future baseline emissions inventories are approved as part of the SIP. With respect to mobile sources, the EPA has taken action in recent years to approve CARB mobile source regulations into the California SIP. 71 We therefore find that the future year baseline projections in the 2020 Plan are properly supported by SIP-approved stationary and mobile source measures. 68 See generally Committee for a Better Arvin v. EPA, 786 F.3d 1169, 1175-1177 (9th Cir. 2015). 69 The EPA's review of District rules relied upon in developing the future baseline emissions inventories is presented in Memorandum to Docket EPA-R09-OAR-2021-0135 from Jeff Wehling, Office of Regional Counsel, EPA Region IX, August 25, 2023. 70 District Rule 61.4.1 should be submitted for approval as part of the SIP; however, the related emissions reductions are not of a magnitude as to implicate the RFP or attainment demonstrations. 71 See 81 FR 39424 (June 16, 2016), 82 FR 14446 (March 21, 2017), and 83 FR 23232 (May 18, 2018). B. Reasonably Available Control Measures Demonstration and Control Strategy 1. Statutory and Regulatory Requirements CAA section 172(c)(1) requires that each attainment plan provide for the implementation of all RACM as expeditiously as practicable (including such reductions in emissions from existing sources in the area as may be obtained through implementation of reasonably available control technology (RACT)), and to provide for attainment of the NAAQS. The 2008 Ozone SRR and the 2015 Ozone SRR require that, for each nonattainment area required to submit an attainment demonstration, the state concurrently submit a SIP revision demonstrating that it has adopted all RACM necessary to demonstrate attainment as expeditiously as practicable and to meet any RFP requirements. 72 72 40 CFR 51.1112(c); 40 CFR 51.1312(c). The “San Diego County area” is shorthand for two nonattainment areas, one for each of two ozone NAAQS: the 2008 and the 2015 ozone NAAQS. The boundary is the same for both areas. Accordingly, the District submitted two attainment demonstrations in the 2020 Plan, one for each of the two standards. The EPA has previously provided guidance interpreting the RACM requirement, in the General Preamble for the Implementation of the Clean Air Act Amendments of 1990 (“General Preamble”) and in a memorandum entitled “Guidance on the Reasonably Available Control Measure Requirement and Attainment Demonstration Submissions for Ozone Nonattainment Areas.” 73 In short, to address the requirement to adopt all RACM, states should consider all potentially reasonable measures for source categories in the nonattainment area to determine whether they are reasonably available for implementation in that area and whether they would, if implemented individually or collectively, advance the area's attainment date by one year or more. 74 Any measures that are necessary to meet these requirements that are not already either federally promulgated, or part of the state's SIP, must be submitted in enforceable form as part of the state's attainment plan for the area. 73 See General Preamble, 57 FR 13498, 13560 (April 16, 1992) and memorandum dated November 30, 1999, from John S. Seitz, Director, OAQPS, to Regional Air Directors, Subject: “Guidance on the Reasonably Available Control Measure Requirement and Attainment Demonstration Submissions for Ozone Nonattainment Areas.” 74 Id. See also 44 FR 20372 (April 4, 1979), and memorandum dated December 14, 2000, from John S. Seitz, Director, OAQPS, to Regional Air Directors, Subject: “Additional Submission on RACM From States with Severe One-Hour Ozone Nonattainment Area SIPs.” For ozone nonattainment areas classified as Moderate or above, CAA section 182(b)(2) also requires implementation of RACT for all major sources of VOC and for each VOC source category for which the EPA has issued a control techniques guideline. CAA section 182(f) requires that RACT under section 182(b)(2) also apply to major stationary sources of NO X . In Severe areas, a major source is a stationary source that emits or has the potential to emit at least 25 tpy of VOC or NO X (CAA sections 182(d) and (f)). Under the 2008 Ozone SRR and the 2015 Ozone SRR, states were required to submit SIP revisions meeting the RACT requirements of CAA sections 182(b)(2) and 182(f) no later than 24 months after the effective date of designation for the 2008 ozone NAAQS and the 2015 ozone NAAQS, respectively. Implementation of the required RACT measures is required as expeditiously as practicable but no later than January 1 of the 5th year after the effective date of designation for the 2008 ozone NAAQS (see 40 CFR 51.1112(a)) and for the 2015 ozone NAAQS (see 40 CFR 51.1312(a)). 75 75 California submitted the CAA section 182 RACT SIP for the San Diego County area for both the 2008 and 2015 ozone NAAQS, as a Severe nonattainment area with a 25 tpy major source threshold, on December 29, 2020. To date, the EPA has taken several actions on the San Diego County RACT SIP. We are not taking action on the RACT SIP in this rulemaking but will be completing action on it in a separate rulemaking(s). 2. Summary of the State's Submission The 2020 Plan presents two RACM demonstrations. The first is included in Section 3.2.1 and addresses the 2008 ozone NAAQS. The second is presented in Section 4.2.1 for the 2015 ozone NAAQS. Within each Section, the 2020 Plan presents a RACM analysis organized by several emissions source groups. The District and CARB each undertook a process to identify and evaluate potential RACM that could contribute to expeditious attainment of the 2008 ozone NAAQS and the 2015 ozone NAAQS in the San Diego County area. In addition, the District presented a “RACM Cumulative Analysis” for each standard as an overarching analysis of all source categories covered by CARB, the District and SANDAG. 76 76 2020 Plan, Sections 3.2.1 and 4.2.1. The 2020 Plan's RACM section for the 2008 ozone NAAQS begins by determining the magnitude of emissions reductions that would be needed to advance the area's attainment date by one year. As noted in Section I.B of this document, air pollutants transported from the South Coast region contribute to higher ozone levels in San Diego County under certain weather conditions. Accordingly, the RACM analysis in the 2020 Plan for the 2008 ozone NAAQS accounts for projected emissions from the San Diego County-South Coast transport couplet. 77 77 2020 Plan, p. 38. In this context, “transport couplet” refers to a “transport couple,” a term that refers to two air basins, one of which has an impact on ambient air pollutant concentrations in the other air basin due to transport of pollutants and precursors by prevailing wind patterns. See “Assessment of the Impacts of Transported Pollutants on Ozone Concentrations in California,” CARB, March 2001. Using emissions levels of the District's chosen 2026 attainment demonstration year as a basis for comparison, the District compared emissions levels from 2026 to what the levels are projected to be one year earlier, that is, 2025. The lower levels in 2026 were then subtracted from the higher levels of emissions in 2025, providing a difference in emissions levels that could then be compared against the 2020 Plan's RACM, that is, emissions reductions from reasonably available control measures, to determine if enough RACM reductions would be available to advance the 2026 attainment year to 2025. These levels are provided in Table 3 of this document. Table 3—Emissions Reductions Needed To Advance Attainment by One Year, 2008 Ozone NAAQS Emissions totals Emissions (tpd) 2026 VOC Emissions Inventory 471.0 2025 VOC Emissions Inventory 473.8 VOC Emissions Reductions Needed in 2025 to Demonstrate Attainment 2.8 2026 NO X Emissions Inventory 344.0 2025 NO X Emissions Inventory 347.4 NO X Emissions Reductions Needed in 2025 to Demonstrate Attainment 3.4 Source: 2020 Plan, Table 3-2 and Table A-2. Because the District's attainment demonstration relies on specific levels of emissions of both VOC and NO X , the reductions of emissions to advance that attainment date one year would require reductions in both VOC and NO X at the levels shown in Table 3, that is, 2.8 tpd of VOC and 3.4 tpd of NO X (“2008 ozone NAAQS RACM targets”). These amounts of reductions are then viewed as targets to see if they can be met or exceeded, and if so, then the attainment year for the 2008 ozone NAAQS would be moved up one year, to 2025. The 2020 Plan groups emissions sources into several large categories and assesses each one to identify potential RACM and to determine their potential collectively to provide emissions reductions equal to or greater than these targets. a. 2008 Ozone NAAQS, District's RACM Analysis The District provides a comprehensive evaluation of its 2008 ozone NAAQS RACM control strategy in Section 3.2.1 (“Reasonably Available Control Measures (RACM) Demonstration”) and Attachments A, D, G, H, I and J of the 2020 Plan. The evaluation includes: source descriptions; base year and projected baseline year emissions for the source category affected by the rule; discussion of the current requirements of the rule; and discussion of potential additional control measures, including, in many cases, a discussion of the technological and economic feasibility of the additional control measures. This includes a comparison of each District rule to analogous control measures adopted by other agencies. The District's RACM demonstration for the 2008 ozone NAAQS begins with an analysis of stationary source controls, described in Section 3.2.1.2 (“Identifying Potential RACM for Stationary Sources”) of the 2020 Plan. This section of the 2020 Plan identifies potential control measures and analyzes these measures for emissions reduction opportunities, as well as economic and technological feasibility. The District's comprehensive demonstration considers potential control measures for stationary sources located throughout the area under its jurisdiction, that is, the entirety of San Diego County. As a first step in the RACM analysis, the District prepared a detailed inventory of emissions sources of VOC and NO X to identify source categories from which emissions reductions would effectively contribute to attainment. Details on the methodology and development of the emissions inventory are discussed in Section 3 and Attachment A of the 2020 Plan. Because the San Diego County area airshed is coupled with the South Coast Air Basin, which was used in the attainment demonstration modeling in the 2020 Plan, the District prepared a “couplet” emissions inventory that includes the two areas' combined emissions. A total of 75 source categories are included in the couplet emissions inventory: 45 for stationary and area sources and 30 for mobile sources. 78 Although the couplet emissions inventory includes South Coast and is therefore used in calculating the 2008 ozone NAAQS RACM targets (2.8 tpd VOC, 3.4 tpd NO X ), only sources of emissions within San Diego County were evaluated for their potential to either meet the 2008 ozone NAAQS RACM targets or to contribute to a collective reduction to meet those targets. 78 2020 Plan, Table A-2. The District compared the 45 source categories to its rules for stationary and area sources. This analysis builds upon a foundation of District rules developed for earlier ozone plans and approved as part of the SIP. These rules establish emissions limits or other types of emissions controls for a wide range of sources, including VOC storage and handling, use of solvents, gasoline storage, gasoline transfer, dry cleaning with petroleum-based solvent, architectural coatings, surface coating operations, marine, wood products and aerospace coating operations, degreasing operations, cutback and emulsified asphalts, kelp processing and biopolymer manufacturing operations, pharmaceutical and cosmetic manufacturing, and bakery ovens, among others. These rules have already provided significant reductions toward attainment of the 2008 ozone NAAQS by 2026. The District excluded RACT rules from their stationary source RACM analysis because those rules are already required by federal law to be included in the SIP and are therefore not “potential” RACM control measures. Likewise, the District excluded stationary and area sources it regulates under the State's requirement to adopt “all feasible measures,” as these measures are also already implemented and incorporated into the area's attainment demonstration, and are therefore also not potential RACM. In addition, California state law requires “Best Available Retrofit Control Technology” or BARCT. 79 Because BARCT is an ongoing requirement for the District, BARCT rules are already implemented, would provide no new emissions reductions, and are therefore not potential RACM. 79 California Health & Safety Code sections 40918, 40919, 40920 and 40920.5. To demonstrate that the SDCAPCD considered all candidate measures that are available and technologically and economically feasible for stationary sources, the District conducted several steps in their analysis. Step 1. Stakeholder Outreach As part of a previous planning effort for the 2008 ozone NAAQS (the 2016 Moderate Plan), 80 and again as part of the SIP development effort for the (Severe) 2020 Plan, the District held multiple stakeholder outreach sessions. These sessions were intended to solicit stakeholder input on the full array of control measures that might be available for emissions sources in the area. Two public workshops were held in July 2020, in addition to other individual stakeholder meetings that were held for feedback on the entire draft 2020 Plan before and after each public workshop. These meetings built upon similar outreach the District conducted for prior federal and state air quality plans, including the 2016 Moderate Plan. 80 The State of California submitted the San Diego County area's 2016 Moderate ozone attainment plan to the EPA as a SIP revision on April 12, 2017. At the time, the area was a Moderate nonattainment area for the 2008 ozone NAAQS. The State withdrew the 2016 Moderate ozone attainment plan by letter dated December 16, 2021 following submittal of the 2020 Plan and the EPA's grant of the State's request to reclassify San Diego County to Severe for the 2008 ozone NAAQS. Step 2. Reasonably Available Control Technology Analysis The District then considered Reasonably Available Control Technology (RACT) stationary source categories and found 11 existing District control measures that could be further controlled when compared to existing rules in other California air districts. 81 These 11 control measures apply to specific types of emissions sources: Receiving and Storing Volatile Organic Compounds at Bulk Plants and Bulk Terminals, Transfer of Organic Compounds into Mobile Transport Tanks, Metal Parts and Product Coating Operations, Paper, Film, and Fabric Coatings, Aerospace Coating Operations, Graphic Arts Operations, Marine Coating Operations, Adhesive Materials Application Operations, Industrial and Commercial Boilers, Process Heaters and Steam Generators, Natural Gas-Fired Fan-Type Central Furnaces, and Stationary Gas Turbine Engines. The SDCAPCD compared its rules to the analogous rules for the same stationary source types in other California air districts, as candidate potential measures, and estimated the potential emissions reductions associated with each control measure if it were modified to reflect the other district's rule. 81 2020 Plan, Table G-1, items G.1 to G.11. Step 3. EPA Technical Support Documents (TSDs) The District researched TSDs from recent EPA rulemakings but did not find any potential additional stationary source controls beyond what its RACT analysis found. 82 82 Email dated August 31, 2023, from Nick Cormier, SDCAPCD, to John J. Kelly, EPA. Step 4. Control Measures in Other Areas The District reviewed stationary source control measures in other areas ( i.e., San Francisco Bay Area, Sacramento, San Joaquin Valley, Santa Barbara, South Coast, and Ventura County) to evaluate whether control technologies available and cost-effective within other areas would be available and cost-effective for use in the San Diego County area. 83 These include six control measures: Vacuum Truck Operations, Miscellaneous NO X Sources, Equipment Leaks, Restaurant Cooking Operations, Food Products Manufacturing/Processing, and Metalworking Fluids and Direct-Contact Lubricants. 83 2020 Plan, Table G-1, items G.12 to G.17. Step 5. EPA Menu of Control Measures The Menu of Control Measures (MCM) 84 compiled by the EPA's Office of Air Quality Planning and Standards was created to provide information useful in the development of emissions reduction strategies and to identify and evaluate potential control measures. District staff reviewed the EPA's MCM for stationary source point and nonpoint sources of NO X and VOC. 84 EPA, MCM, April 12, 2012. Based on its evaluation of all available stationary source control measures, the District concluded that its existing rules are generally as stringent as analogous rules in other districts, and where they were not, quantified the difference. In all, the District estimated that the total possible emissions reductions from further control of stationary sources subject to existing District rules and control of additional source categories would be approximately 0.4 tpd for VOC and 0.4 tpd for NO X . 85 85 2020 Plan, Attachment G, Table G-1. b. 2008 Ozone NAAQS, RACM Analysis for Transportation Control Measures Attachment H of the 2020 Plan contains the District's transportation control measure (TCM) RACM evaluation. The implemented TCMs in Attachment H are applicable in San Diego County. The District conducted the TCM RACM analysis on behalf of SANDAG and local jurisdictions in San Diego County, based on SANDAG's regional transportation plan (RTP), specifically, “San Diego Forward: The 2019 Federal Regional Transportation Plan” (“2019 RTP”). 86 The 2019 RTP was developed in consultation with federal, state and local transportation and air quality planning agencies and other stakeholders. 86 The 2019 RTP was adopted by SANDAG's Board on October 25, 2019. The 2019 RTP was approved by the Federal Highway Administration on November 15, 2019. As described in Attachment H of the 2020 Plan, for the TCM RACM analysis, the District listed all TCMs that are included in CAA section 108(f) and their implementation status in San Diego County. 87 Of the 16 TCMs listed in CAA section 108(f), 13 are implemented in San Diego County. Of these implemented TCMs, five were included in the area's 1982 SIP. 87 2020 Plan, Attachment H, “Implementation Status of Transportation Control Measures,” Table H-1. Of the three TCMs that are not implemented in San Diego County, one (“Trip Reduction Ordinances”) was adopted in 1994, but was then rescinded in 1995 when federal and State laws were amended eliminating the mandate for such measures. 88 Another (“Programs to limit or restrict vehicle use in downtown areas or other areas of emission concentration particularly during periods of peak use” or “Peak Use Restriction Programs”) was found to be infeasible due to San Diego's low-density land use pattern and accompanying longer transit travel times. However, the District notes that SANDAG's Smart Growth Incentive Program provides funding to cities in San Diego County for infrastructure projects that enhance alternatives to driving in higher density areas. 88 As amended in 1990, CAA section 182(d)(1)(B) required states with Severe ozone nonattainment areas to adopt and submit SIP revisions requiring employers in such areas to implement programs to reduce work-related vehicle trips and miles traveled by employees, commonly referred to as “trip reduction ordinances.” Amendments to the CAA promulgated in 1995 revised CAA section 182(d)(1)(B) such that trip reduction ordinances are no longer required but may be adopted and submitted as SIP revisions at the state's discretion. Finally, one TCM, (“Programs to reduce motor vehicle emissions, consistent with Title II, which are caused by extreme cold start conditions” or “Cold Weather Start Programs”) was found to be not applicable to San Diego County due to its mild climate. Based on its review of TCM projects implemented in San Diego County, the District determined that 13 of the 16 TCMs listed in CAA section 108(f) are being implemented in the county and are therefore ineligible for consideration as potential RACM. To determine if the three unimplemented TCMs could be required as RACM, the District estimated the maximum emissions reductions to be attributed to those TCMs. The 2020 Plan estimates the maximum emissions reduction potential of the three unimplemented TCMs, citing a 1992 SANDAG study that estimated maximum emissions reductions for Trip Reduction Ordinances alone at less than 2 percent of on-road vehicle emissions. 89 The 1992 SANDAG study also found that potential reductions of all 15 of the other TCMs combined do not equal the Trip Reduction Ordinances TCM alone. Therefore, the 2020 Plan estimates the maximum potential emissions reduction potential of the three unimplemented TCMs as 2 percent of on-road vehicle emissions in a given year. For the modeled attainment year, 2026, projected on-road motor vehicle emissions in San Diego County are 12.2 tpd VOC and 17.5 tpd NO X . Two percent of these projected emissions is 0.2 tpd VOC and 0.4 tpd NO X . 89 “Transportation Control Measures for the Air Quality Plan,” SANDAG, 1992. c. 2008 Ozone NAAQS, CARB's RACM Analysis CARB's RACM analysis is contained in Attachment I (“CARB Analyses of Potential Additional Mobile Source and Consumer Products Control Measures”) (“CARB RACM assessment”) of the 2020 Plan. The CARB RACM analysis provides a general description of CARB's existing mobile source programs. In its analysis, CARB includes mobile source control measures described in CARB's “2016 State Strategy for the State Implementation Plan” (2016 State Strategy). 90 A more detailed description of CARB's mobile source control program, including a comprehensive table listing on- and off-road mobile source regulatory actions taken by CARB from 1985 to 2019, is contained in Attachment D of the 2020 Plan (“CARB Control Measures, 1985 to 2019 (March 2020)”). CARB's RACM analysis and 2016 State Strategy collectively contain CARB's evaluation of mobile source and other statewide control measures that reduce emissions of NO X and VOC in California, including San Diego County. 90 CARB's 2016 State Strategy is available in the docket for this action and at https://ww3.arb.ca.gov/planning/sip/2016sip/rev2016statesip.pdf . Source categories for which CARB has primary responsibility for reducing emissions in California include most new and existing on- and off-road engines and vehicles, motor vehicle fuels, and consumer products. CARB developed its 2016 State Strategy through a multi-step measure development process, including extensive public consultation, to develop and evaluate potential strategies for mobile source categories under CARB's regulatory authority that could contribute to expeditious attainment of the standard. 91 Through the process of developing the 2016 State Strategy, CARB identified certain defined measures as available to achieve additional VOC and NO X emissions reductions from sources under CARB jurisdiction, including tighter requirements for new light- and medium-duty vehicles (referred to as the “Advanced Clean Cars 2” measure), a low-NO X engine standard for vehicles with new heavy-duty engines, tighter emissions standards for small off-road engines, and more stringent requirements for consumer products, among others. 92 In adopting the 2016 State Strategy, CARB committed to bringing the defined measures to the CARB Board for action according to the specific schedule included as part of the strategy. 93 91 2020 Plan, p. I-2. 92 2016 State Strategy, Chapter 4 (“State SIP Measures”). 93 CARB Resolution 17-7 (dated March 23, 2017), p. 7. CARB's resolution is available in the docket for this action and at https://ww3.arb.ca.gov/planning/sip/2016sip/res17-7.pdf . Given the need for substantial emissions reductions from mobile and area sources to meet the NAAQS in California nonattainment areas, CARB established stringent control measures for on-road and off-road mobile sources and the fuels that power them. California has unique authority under CAA section 209 (subject to a waiver by the EPA) to adopt and implement new emission standards for many categories of on-road vehicles and engines, and new and in-use off-road vehicles and engines. CARB's mobile source program extends beyond regulations that are subject to the waiver or authorization process set forth in CAA section 209 to include standards and other requirements to control emissions from in-use heavy-duty trucks and buses, gasoline and diesel fuel specifications, and many other types of mobile sources. Generally, these regulations have been submitted and approved as revisions to the California SIP. 94 94 See, e.g., the EPA's approval of standards and other requirements to control emissions from in-use heavy-duty diesel-powered trucks, at 77 FR 20308 (April 4, 2012), revisions to the California on-road reformulated gasoline and diesel fuel regulations at 75 FR 26653 (May 12, 2010), and revisions to the California motor vehicle inspection and maintenance program at 75 FR 38023 (July 1, 2010). In their RACM analysis, CARB concludes that, in light of the extensive public process culminating in the 2016 State Strategy, with the current mobile source program and proposed measures included in the 2016 State Strategy, there are no additional mobile source RACM that would advance attainment of the 2008 ozone NAAQS in San Diego County. As a result, CARB concludes that California's mobile source programs fully meet the RACM requirement. 95 95 2020 Plan, p. I-6. Attachment I of the 2020 Plan describes CARB's current consumer products program and commitments in the 2016 State Strategy to achieve additional VOC reductions from consumer products. 96 As described in Attachment I, CARB's current consumer products program limits VOC emissions from 129 consumer product categories, including product categories such as antiperspirants and deodorants and aerosol coatings. 97 The EPA has approved these measures into the California SIP as VOC emissions controls for a wide array of consumer products. 98 96 Id., pp. I-6, I-7. CARB's consumer product measures are found in the California Code of Regulations, Title 17 (“Public Health”), Division 3 (“Air Resources”), Chapter 1 (“Air Resources Board”), Subchapter 8.5 (“Consumer Products”). 97 Id., p. D-34. 98 The compilation of such measures that have been approved into the California SIP, including Federal Register citations, is available at: https://www.epa.gov/sips-ca/epa-approved-regulations-california-sip . EPA's most recent approval of amendments to California's consumer products regulations was in 2020. 85 FR 57703 (September 16, 2020). d. 2008 Ozone NAAQS, the District's RACM Conclusion In addition to evaluating a number of stationary, area, and mobile sources, as well as consumer products, in the separate groups as described in Section III.B.a. to Section III.B.c. in this document, the District presents a “cumulative analysis” to assess whether all potential RACM combined could result in advancement of the modeled 2026 attainment year to 2025. 99 Attachment J (“Calculation of Cumulative Potential Emission Reductions for Possible Reasonably Available Control Measures (RACM)”) of the 2020 Plan presents the cumulative potential RACM. 100 When taken together, all potential RACM reductions of VOC and NO X that the District and CARB evaluated amount to approximately 0.7 tpd VOC and 0.7 tpd NO X . These amounts fall far short of the 2008 ozone RACM targets of 2.8 tpd VOC and 3.4 tpd NO X . 101 The District therefore concludes that, collectively, there are not enough potential RACM reductions to advance the attainment date. 99 2020 Plan, Section 3.2.1.6, “RACM Cumulative Analysis,” pp. 41-42. 100 Id., Table J-1. 101 Although the District based its RACM analysis for the 2008 ozone NAAQS on emissions reductions in the San Diego County-South Coast transport couplet, the District also analyzed emissions reductions from the District alone and also concluded that the attainment year could not be advanced one year with RACM emissions reductions. See email dated August 9, 2023, from Nick Cormier, SDCAPCD, to Jefferson Wehling, EPA. e. 2015 Ozone NAAQS, RACM In addition to addressing RACM for the 2008 ozone NAAQS, the 2020 Plan addresses RACM for the 2015 NAAQS. Section 4.2.1, “Reasonably Available Control Measures (RACM) Demonstration,” of the 2020 Plan contains the plan's RACM demonstration for the 2015 ozone NAAQS. The demonstration reflects much of what the 2020 Plan presents for demonstrating RACM for the 2008 ozone NAAQS and relies on the same attachments described in Section III.B.2.a.-d. of this document, that is, Attachments A (“Emissions Inventories and Documentation for Baseline, RFP, and Attainment Years”), D (“CARB Control Measures, 1985 to 2019”), G (“Analyses of Potential Additional Stationary Source Control Measures”), H (“Implementation Status of Transportation Control Measures”), I (“CARB Analyses of Potential Additional Mobile Source and Consumer Products Control Measures”), and J (“Calculation of Cumulative Potential Emission Reductions for Possible Reasonably Available Control Measures (RACM”). In the 2020 Plan, the District compares 2032 projected emissions of the ozone precursors VOC and NO X to those of the year prior, 2031, to determine the amount of emissions reductions that would be necessary in order to advance attainment by one year, to 2031, providing a 2015 ozone NAAQS RACM target. These levels are provided in Table 4 of this document. Unlike the emissions projections used to determine the magnitude of emissions reductions that would be necessary to advance attainment by one year for the RACM demonstration for the 2008 ozone NAAQS, the emissions projections used to determine the magnitude of emissions reductions necessary to advance attainment by one year for the RACM demonstration for the 2015 ozone NAAQS reflect emissions only for San Diego County ( i.e., including marine emissions 3 to 100 NM off the County coastline) rather than those for the South Coast-San Diego couplet. Using this more conservative approach, the District determined that VOC reductions of 0.1 tpd and NO X reductions of 5.9 tpd would advance the attainment date for the 2015 ozone NAAQS by one year. 102 102 2020 Plan, Table 4-2, p. 58. Table 4—Emissions Reductions Needed To Advance Attainment by One Year, 2015 Ozone NAAQS Emissions totals Emissions (tpd) 2032 VOC Emissions Inventory 98.3 2031 VOC Emissions Inventory 98.4 VOC Emissions Reductions Needed in 2031 to Demonstrate Attainment 0.1 2032 NO X Emissions Inventory * 63.3 2031 NO X Emissions Inventory 69.2 NO X Emissions Reductions Needed in 2025 to Demonstrate Attainment 5.9 Source: 2020 Plan, Table 4-2, “Emissions Reductions Required to Advance Attainment By One Year, 2015 Ozone NAAQS (tons per day).” * Adjusted for RACM. The unadjusted 2032 NO X emissions inventory for San Diego County is 69.0 tpd. However, for attainment purposes, CARB has committed to obtain additional emissions reductions, in the amount of 4 tpd NO X , as described in Section 4.3.5 of the 2020 Plan, and 1.7 tpd NO X , as described in Section 4.3.4 of the 2020 Plan and in Attachment L, Section L.3.9. These commitments add up to 5.7 tpd NO X , leaving a total emissions inventory of NO X in 2032 of 63.3 tpd. Once the District identifies 2015 ozone NAAQS RACM targets (0.1 tpd VOC, 5.9 tpd NO X ) in the 2020 Plan, the District assesses all potential RACM reductions to determine if, collectively, they could equal or exceed the targets. The District analyzes these potential RACM reductions in essentially the same steps as those taken to assess potential RACM for the 2008 ozone NAAQS, starting with stationary sources. As described in Section III.B.2.a. of this document, for the stationary source portion of the RACM demonstration for the 2008 ozone NAAQS, if all potential stationary source RACM were adopted in the area, stationary source emissions would be reduced an additional 0.41 tpd for VOC and 0.40 tpd for NO X . 103 With respect to TCMs, the District estimates that if all unimplemented TCMs were to be adopted, transportation-related emissions sources in San Diego County would be reduced by 2 percent of the on-road motor vehicle emissions inventory for year 2032, or approximately 0.2 tpd VOC and 0.3 tpd NO X . For mobile sources and consumer products, the District concludes in the 2020 Plan that there are no potential RACM reductions available since all reasonable rules regulating both are currently being implemented. 104 In the 2020 Plan, the District bases this conclusion on analysis performed by CARB in Attachment I, which we describe in Section III.B.2.c. of this document regarding 2008 ozone NAAQS RACM. 103 2020 Plan, Attachment G, Table G-1, “Stationary Source Categories for Which More Stringent Control Requirements Have Been Adopted by Another Air District,” p. G-1. 104 Id., Section 4.2.1.5, “Identifying Potential RACM for Mobile Sources and Consumer Products,” 61, and Attachment I, “CARB Analyses of Potential Additional Mobile Source and Consumer Products Control Measures.” The District included an additional step in its RACM analysis for the 2015 ozone NAAQS, which was not performed for the 2008 ozone NAAQS. The purpose was to determine whether further reductions would be possible, given that the area's 2032 modeled attainment year was further in the future for the 2015 ozone NAAQS than for the 2008 ozone NAAQS (2026). The District assessed the top ten non-mobile source categories of VOC and NO X in San Diego County's emissions inventory. 105 105 Id., Attachment A-1, Table A-1. For each of these categories, the District estimates the percentage of the county's 2032 emissions of VOC and NO X . 106 In each of two tables in the 2020 Plan (Table 4-3 and Table 4-4), the District provides, for each category: the numerical ranking from 1 to 10, with 1 representing the category with the highest emissions of all ten categories; the source category name; the emission inventory code or EIC; 107 2017 base year and 2032 projected attainment year emissions of VOC or NO X ; the percentage of the County's projected 2032 total emissions of VOC or NO X ; a description of applicable regulations for the category; and whether there are potential RACM reductions, with an accompanying justification. The purpose of this last item, potential RACM and justification, is to determine first if there are RACM reductions available. A “yes” in this column indicates that the category has further reductions that are not being implemented. A “no” indicates that the category has no potential RACM reductions. Justifications for a “no” in this column vary. For example, the number 1 category of VOC non-mobile emissions is Consumer Products. These were discussed in both the 2008 and 2015 ozone NAAQS RACM sections in the 2020 Plan. In both instances, the conclusions, based on the analyses provided, are that there are no further CARB Consumer Products regulations to put in place. 106 Id., Table 4-3, “Top Ten Categories of VOC Emissions in 2032 (Non-Mobile),” and Table 4-4, “Top Ten Categories of NO X Emissions in 2032 (Non-Mobile).” 107 Emissions inventory source categories are represented by a 14-digit emission inventory code (EIC) for area and mobile sources. In the 2020 Plan, text accompanying each of these two tables (that is, Tables 4-3 and 4-4) provides further assessment of each category. To continue the example for Consumer Products, the text explains that CARB has been developing regulations for this category for thirty years, developing regulations for over 100 consumer product categories. These regulations have been amended frequently, with increasing levels of stringency for VOC limits and reactivity limits. In each of these two tables, the District demonstrates that the top ten categories of VOC and NO X are addressed in the 2020 Plan. Where a potential for RACM exists, each category is addressed in the 2020 Plan in Sections 3.2.1.1 and 4.2.1.1 regarding RACM for the 2008 and 2015 ozone NAAQS, respectively, and in Attachment G. f. 2015 Ozone NAAQS, the District's RACM Conclusion After evaluating the emissions reduction potentials of stationary, area, and mobile sources, as well as consumer products, by themselves, the District presents a “cumulative analysis” to assess whether all potential RACM combined could result in advancement of the modeled 2032 attainment year to 2031. 108 Attachment J (“Calculation of Cumulative Potential Emission Reductions for Possible Reasonably Available Control Measures (RACM)”) of the 2020 Plan presents the cumulative potential RACM reductions in Table J-1, “Calculation of Cumulative Potential Emission Reductions for Possible Reasonably Available Control Measures (RACM).” When taken together, all potential RACM reductions of VOC and NO X that the District and CARB evaluated amount to approximately 0.6 tpd VOC and 0.7 tpd NO X . The potential RACM for combined VOC and NO X , 1.3 tpd potential RACM reduction falls far short of the 2015 ozone RACM target (for combined VOC and NO X ), 6.0 tpd. The District therefore concludes that collectively, there is not enough potential RACM reductions to advance the attainment date for the 2015 ozone NAAQS. 108 2020 Plan, Section 4.2.1.7, “RACM Cumulative Analysis,” p. 74. 3. The EPA's Review of the State's Submission As described in Section III.B.2.a. of this document, the District already implements many rules to reduce VOC and NO X emissions from stationary and area sources in the San Diego County area. For the 2020 Plan, the District evaluated a range of potentially available measures. We find that the process followed by the District in the 2020 Plan to identify additional stationary and area source RACM is generally consistent with the EPA's recommendations in the General Preamble, that the District's evaluation of potential measures is appropriate, and that the District has provided reasoned justifications for rejection of measures deemed not reasonably available. With respect to mobile sources, CARB's current program addresses the full range of mobile sources in the San Diego County area through regulatory programs for both new and in-use vehicles. With respect to TCMs, we find that the District's process for identifying additional TCM RACM and its conclusion that the TCMs being implemented in the San Diego County area ( i.e., the TCMs listed in Attachment H of the 2020 Plan) represents all TCM RACM to be reasonably justified and supported. Further, we find that the District's cumulative analyses appropriately sum the various sources of potential RACM, and we agree with the District's conclusion that, taken together, all potential RACM would advance neither the 2026 modeled attainment year for the 2008 ozone NAAQS, nor the 2032 modeled attainment year for the 2015 ozone NAAQS. Based on our review of these RACM analyses and the District's and CARB's adopted rules, we propose to find that there are currently no additional RACM that would advance attainment of either the 2008 ozone NAAQS or the 2015 ozone NAAQS in the San Diego County area, and that the 2020 Plan provides for the implementation of all RACM as required by CAA section 172(c)(1), 40 CFR 51.1112(c) and 40 CFR 51.1312(c). C. Attainment Demonstration 1. Statutory and Regulatory Requirements An attainment demonstration consists of: (1) technical analyses, such as base year and future year modeling, to locate and identify sources of emissions that are contributing to violations of the ozone NAAQS within the nonattainment area ( i.e., analyses related to the emissions inventory for the nonattainment area and the emissions reductions necessary to attain the standards); (2) a list of adopted measures (including RACT controls) with schedules for implementation and other means and techniques necessary and appropriate for demonstrating RFP and attainment as expeditiously as practicable but no later than the outside attainment date for the area's classification; (3) a RACM analysis; and (4) contingency measures required under sections 172(c)(9) and 182(c)(9) of the CAA that can be implemented without further action by the state or the EPA to cover emissions shortfalls in RFP and failures to attain. 109 In this section, we address the first two components of the attainment demonstration—the technical analyses and a list of adopted measures. We address the RACM component of the 2020 Plan attainment demonstration in Section III.B (Reasonably Available Control Measures Demonstration and Control Strategy) of this document and the contingency measures component of the attainment demonstration in Section III.F (Contingency Measures) of this document. 109 78 FR 34178, 34184 (June 6, 2013) (proposed rule for implementing the 2008 ozone NAAQS), codified at 40 CFR 51.1108. For the 2015 ozone NAAQS, the EPA finalized modeling requirements at 40 CFR 51.1308. With respect to the technical analyses, section 182(c)(2)(A) of the CAA requires that a plan for an ozone nonattainment area classified Serious or above include a “demonstration that the plan . . . will provide for attainment of the ozone [NAAQS] by the applicable attainment date. This attainment demonstration must be based on photochemical grid modeling or any other analytical method determined . . . to be at least as effective.” The attainment demonstration predicts future ambient concentrations for comparison to the NAAQS, making use of available information on measured concentrations, meteorology, and current and projected emissions inventories of ozone precursors, including the effect of control measures in the plan. Areas classified Severe for the 2008 and 2015 ozone NAAQS must demonstrate attainment as expeditiously as practicable, but no later than 15 years after the effective date of designation to nonattainment. San Diego County was designated nonattainment for the 2008 ozone NAAQS effective July 20, 2012, and for the 2015 ozone NAAQS, the area was designated nonattainment effective August 3, 2018. 110 Accordingly the area must demonstrate attainment of the 2008 ozone NAAQS by July 20, 2027; for the 2015 ozone NAAQS, the area must demonstrate attainment by August 3, 2033. 111 An attainment demonstration must show attainment of the standards by the ozone season (for San Diego County, the ozone season is the entire calendar year) prior to the attainment date, so in practice, Severe nonattainment areas must demonstrate attainment in 2026 for the 2008 ozone NAAQS and in 2032 for the 2015 ozone NAAQS. 110 77 FR 30087 (May 21, 2012) and 83 FR 25776 (June 4, 2018), respectively. 111 80 FR 12264 and 83 FR 62998, respectively. The EPA's recommended procedures for modeling ozone as part of an attainment demonstration are contained in “Modeling Guidance for Demonstrating Air Quality Goals for Ozone, PM 2.5 , and Regional Haze” (“Modeling Guidance”). 112 The Modeling Guidance includes recommendations for a modeling protocol, model input preparation, model performance evaluation, use of model output for the numerical NAAQS attainment test, and modeling documentation. Air quality modeling is performed using meteorology and emissions from a base year, and the predicted concentrations from this base case modeling are compared to air quality monitoring data from that year to evaluate model performance. 112 Modeling Guidance, EPA 454/R-18-009, November 2018. Additional EPA modeling guidance can be found in 40 CFR 51 Appendix W, “Guideline on Air Quality Models,” 82 FR 5182 (January 17, 2017). These documents are available in the docket for this action and at https://www.epa.gov/sites/default/files/2020-10/documents/o3-pm-rh-modeling_guidance-2018.pdf and https://www.epa.gov/scram/clean-air-act-permit-modeling-guidance, respectively. Once the model performance is determined to be acceptable, future year emissions are simulated with the model. The relative (or percent) change in modeled concentration due to future emissions reductions provides a relative response factor (RRF). Each monitoring site's RRF is applied to its monitored base year design value to provide the future design value for comparison to the NAAQS. The Modeling Guidance also recommends supplemental air quality analyses, which may be used as part of a weight of evidence analysis. A weight of evidence analysis corroborates the attainment demonstration by considering evidence other than the main air quality modeling attainment test, such as trends and additional monitoring and modeling analyses. Lastly, an unmonitored area analysis is used to predict areas of high ozone concentrations where air quality monitoring data is not available. This analysis utilizes interpolated ambient data with modeled outputs to determine gradient-adjusted spatial fields. Section 4.7 of the Modeling Guidance provides guidelines for estimating design values at unmonitored grid cells. The Modeling Guidance does not require a particular year to be used as the base year for 8-hour ozone plans. 113 The Modeling Guidance states that the most recent year of the National Emissions Inventory 114 may be appropriate for use as the base year for modeling, but that other years may be more appropriate when considering meteorology, transport patterns, exceptional events, or other factors that may vary from year to year. 115 Therefore, the base year used for the attainment demonstration need not be the same year used to meet the requirements for emissions inventories and RFP. 113 Modeling Guidance, Section 2.7.1, p. 35. 114 The National Emissions Inventory (NEI) is an electronic database of criteria pollutant and precursor emissions data for the United States. State, local and tribal agencies contribute to the NEI every three years (2011, 2014, 2017, 2020, etc.). For more information about the NEI, see: https://www.epa.gov/air-emissions-inventories/national-emissions-inventory-nei. 115 Modeling Guidance at Section 2.7.1, p 35. With respect to the list of adopted measures, CAA section 172(c)(6) requires that nonattainment area plans include enforceable emissions limitations, and such other control measures, means or techniques (including economic incentives such as fees, marketable permits, and auctions of emission rights), as well as schedules and timetables for compliance, as may be necessary or appropriate to provide for timely attainment of the NAAQS. 116 Under the 2008 Ozone SRR and the 2015 Ozone SRR, all control measures needed for attainment must be implemented no later than the beginning of the attainment year ozone season. 117 The attainment year ozone season is defined as the ozone season immediately preceding a nonattainment area's maximum attainment date. 118 116 See also CAA section 110(a)(2)(A). 117 40 CFR 51.1108(d) and 40 CFR 51.1308(d), respectively. 118 40 CFR 51.1100(h) for the 2008 ozone NAAQS and 40 CFR 51.1300(g), for the 2015 ozone NAAQS. 2. Summary of the State's Submission a. Photochemical Modeling The 2020 San Diego County Ozone SIP includes photochemical modeling for the 2008 and 2015 ozone NAAQS. CARB performed the air quality modeling for the 2020 Plan. The modeling relies on a 2017 base year and demonstrates attainment of the 2008 ozone NAAQS in 2026 and attainment of the 2015 ozone NAAQS in 2032. As a general matter, the modeling for the 2020 Plan represents the most up-to-date photochemical modeling performed for the area, accounting for improved chemical gaseous and particulate mechanisms, improved computational resources and post-processing utilities, enhanced spatial and temporal allocations of the emissions inventory, and CARB's latest attainment demonstration methodology. Air quality modeling included in the 2020 Plan is described briefly in the plan's Sections 3.3 and 4.3 (for 2008 and 2015 ozone NAAQS, respectively) and in detail in the plan's Attachment K (“Attachment K” or “Modeling Protocol”). 119 The 2020 Plan discusses its modeling emissions inventory in Attachment L, “Modeling Emissions Inventory,” while Attachment M, “Weight of Evidence Demonstration for San Diego County,” supplements the plan's modeling results with a weight of evidence analysis. 119 2020 Plan, Attachment K, “Modeling Protocol & Attainment Demonstration for the 2020 San Diego Ozone SIP” (March 2020). Attachment K of the 2020 Plan provides a description of model input preparation procedures, various model configuration options, and model performance statistics. The Modeling Protocol contains all the elements recommended in the Modeling Guidance, including: selection of model, time period to model, modeling domain, and model boundary conditions and initialization procedures; a discussion of emissions inventory development and other model input preparation procedures; model performance evaluation procedures; selection of days; and other details for calculating Relative Response Factors (RRFs). Attachment K also provides the coordinates of the modeling domain. Attachment L of the 2020 Plan thoroughly describes the development of the modeling emissions inventory, including its chemical speciation, its spatial and temporal allocation, its temperature dependence, and quality assurance procedures. The CARB Staff Report for the 2020 Plan provides additional information about CAA requirements that apply to the San Diego County area, including an attainment demonstration, emissions reductions commitments by CARB and the District and the source categories from which those reductions are expected to come. 120 120 Emissions reduction commitments are described in the 2020 Plan (Sections 4.3.4 and 4.3.5; Attachment L, Section 3.9; and Table 4-9), the CARB Staff Report, and the District's and CARB's Board resolutions. The modeling analysis uses version 5.2.1 of the Community Multiscale Air Quality (CMAQ) photochemical model, developed by the EPA. To prepare meteorological input for CMAQ, the Weather Research and Forecasting model version 3.9.1.1 (WRF) from the National Center for Atmospheric Research was used. CMAQ and WRF are both recognized in the Modeling Guidance as technically sound, state-of-the-art models. The areal extent and the horizontal and vertical resolution used in these models are adequate for modeling San Diego County ozone. The WRF meteorological model results and performance statistics are described in Section K.3.1 (“Meteorological Model Evaluation”) of Attachment K. The District and CARB evaluated the performance of the WRF model through a series of simulations and concluded that the daily WRF simulation for 2017 performed comparably to recent WRF modeling studies of ozone formation in California. The District's conclusions are supported by hourly time series, with performance statistics provided in Table K-7 for wind speed, temperature and relative humidity. Ozone model performance and related statistics are described in the 2020 Plan Attachment K, Section K.3.2 (“Air Quality Model Evaluation”), which includes tables of statistics recommended in the Modeling Guidance for ozone for San Diego County. Model performance metrics provided in the 2020 Plan include mean bias, mean error, mean fractional bias, mean fractional error, normalized mean bias, normalized mean error, root mean square error, and correlation coefficient. In addition, plots were provided in evaluating the modeling: time-series plots comparing the predictions and observations, scatter plots for comparing the magnitude of the simulated and observed mixing ratios, box plots to summarize the time series data across different regions and averaging times, as well as frequency distributions. After model performance for the 2017 base case was accepted, the model was applied to develop RRFs for the attainment demonstration. 121 This entailed running the model with the same meteorological inputs as before, but with adjusted emissions inventories to reflect the expected changes between 2017 and the attainment years 2026 and 2032. The base year, or “reference year” as referred to by the District and CARB, modeling inventory was the same as the inventory for the modeling base case, except for the exclusion of some emissions events that are random or cannot be projected to the future. 122 The 2026 and 2032 inventories project the base year into the future by including the effect of economic growth and emissions control measures. To develop the RRFs for the 8-hour ozone NAAQS, only the top 10 modeled days were used, consistent with the Modeling Guidance. 123 121 Modeling TSD, p. 26. Section 4.0 of the Modeling Guidance focuses on establishing guidelines for analyzing simulated emissions reductions for a future year with the goal of meeting the NAAQS. The Modeling Guidance recommends examining relative changes in design values through Relative Response Factors instead of absolute values to reduce the effect of model biases. In short, the RRF is a relative change in concentration with respect to a change in emissions between a base and future year, i.e., the ratio of future year and base year modeled concentrations, and is multiplied by the base design value obtained from monitoring data at a particular site to obtain a future year design value at that site. 122 The terms base year and reference year can be used interchangeably. To use consistent EPA terminology, the terms “base year” and “base case” are used in this document and correspond to the District's and CARB's use of the terms “reference year” and “base year,” respectively. 123 See Modeling Guidance at section 4.2.1. The Modeling Guidance addresses attainment demonstrations with ozone NAAQS based on 8-hour averages, and for the 2008 and 2015 ozone NAAQS, the 2020 Plan carried out the attainment test procedure consistent with the Modeling Guidance. The RRFs were calculated as the ratio of future to base year concentrations. The resulting RRFs were then applied to two sets of reference design values. One set is for the period 2016-2018. Another set of design values was more current at the time of the state and District's analysis, the period 2017-2019. However, because that set of design values included data for 2019 that was not finalized at the time of the analysis, the earlier 2016-2018 set was used as an additional reference. The RRFs were applied to five monitoring sites in the San Diego County area to obtain future year 2026 and 2032 design values, summarized in Table K-13 and Table K-14 of the 2020 Plan, respectively. The modeled 2026 and 2032 ozone design values at the Alpine monitoring site (the highest of the county's monitors) are 0.074 ppm and 0.070 ppm, respectively; these values demonstrate attainment of the 2008 and the 2015 ozone NAAQS. The 2020 Plan modeling demonstration includes a weight of evidence demonstration. 124 The weight of evidence demonstration in Attachment M of the 2020 Plan includes ambient ozone data and trends, precursor emissions trends and reductions, to complement the regional photochemical modeling analyses. The CARB Staff Report for the 2020 Plan concludes that the weight of evidence analysis supports the conclusions of the photochemical modeling. 125 124 2020 Plan, Attachment M, “Weight of Evidence Demonstration for San Diego County.” 125 CARB Staff Report, 10. b. Control Strategy for the 2008 Ozone NAAQS and for the 2015 Ozone NAAQS Continued air quality improvement in the San Diego County area is expected during the 2017 through 2032 timeframe because of the continued implementation of adopted District and CARB control measures and ongoing fleet turnover that replaces older more polluting mobile sources with newer, cleaner models and the downward emissions trends in the upwind South Coast Air Basin. The control strategy for the San Diego County area for the 2008 ozone NAAQS relies on emissions reductions from baseline (already-implemented) measures. The baseline control measures include the District's stationary source rules and CARB's mobile source and consumer products regulations adopted at the time of development of the 2020 Plan. The control strategy for the San Diego County area for the 2015 ozone NAAQS also relies on emissions reductions from baseline (already-implemented) measures. However, unlike the 2008 ozone NAAQS attainment demonstration, the 2020 Plan concludes that baseline measures will not by themselves provide sufficient emissions reductions by 2032 to demonstrate attainment of the 2015 ozone NAAQS. Thus, the control strategy for the attainment demonstration for the 2015 ozone NAAQS includes commitments by CARB and the District to adopt and submit new control measures to achieve additional emissions reductions that the modeling indicates are necessary to attain the 2015 ozone NAAQS in the San Diego County area by the attainment year (2032). To provide for attainment of the 2015 ozone NAAQS by the attainment year (2032), CARB and the District commit in the 2020 Plan to reduce NO X emissions by 4.0 tpd 126 and by 1.7 tpd, 127 respectively. CARB expects to adopt and submit certain mobile source control measures developed pursuant to CARB's 2016 State Strategy to fulfill the 4.0 tpd NO X aggregate emissions reduction commitment for San Diego County by 2032. The specific control measures that CARB expects to adopt and submit are listed in Table 5 of this document. The District expects to adopt and submit certain stationary source control measures to fulfill the 1.7 tpd NO X aggregate emissions reduction commitment by 2032, as listed in Table 6 of this document. 126 CARB Board Resolution 20-29, 6; 2020 Plan, section 4.3.5. 127 2020 Plan, section 4.3.4. Table 5—San Diego County Expected NO X Emissions Reductions From CARB 2016 State SIP Strategy Measures 2016 State strategy measure(s) Control measure/regulation 2032 (tpd) On-Road Heavy-Duty Vehicles: Low-NO X Engine Standard—California Action and Lower In-Use Emission Performance Level Heavy-Duty Engine and Vehicle Omnibus Regulation (“Low NO X Omnibus Regulation”) 1.9 On-Road Heavy-Duty Vehicles: Last Mile Delivery Advanced Clean Trucks Regulation 0.4 On-Road Heavy-Duty Vehicles: Lower In-Use Emission Performance Level Heavy Duty Vehicle Inspection and Maintenance Regulation 1.7 Total Aggregate CARB Commitment 4.0 Sources: 2016 State Strategy, Chapters 3 and 4; 2020 Plan, Table 4-9. Table 6—San Diego County Expected NO X Emissions Reductions From SDCAPCD Control Measures Source type Control measure/rule 2032 (tpd) Stationary Reciprocating Internal Combustion Engines Amended District Rule 69.4.1 0.8 Small and Medium Boilers, Process Heaters, Steam Generators and Large Water Heaters New or Amended District Rules 69.2.1 and 69.2.2 0.9 Total Aggregate SDCAPCD Commitment 1.7 Source: 2020 Plan, Section 4.3.4. c. Attainment Demonstration Table 7 of this document summarizes the attainment demonstration for the 2008 ozone NAAQS by listing the 2011 base year emissions level, the attainment year (2026) baseline emissions level, the modeled attainment (2026) emissions level, and the reductions that the District and CARB estimate will be achieved through implementation of baseline ( i.e., adopted) measures taking into account area-wide growth, the growth increments for the military and SDIA, the District's ERC set-aside and the EMFAC2017 Adjustment Factors adjustment. The District and CARB have not made any emissions reductions commitments as part of the control strategy for attainment of the 2008 ozone NAAQS in San Diego County. The control strategy relies only on baseline measures. As shown in Table 7, baseline measures are expected to reduce base year (2011) emissions of NO X by 43 percent and VOC emissions by 27 percent by the 2026 attainment year, notwithstanding area-wide growth, the growth increments for the military and SDIA, the District's ERC set-aside and the EMFAC2017 Adjustment Factors adjustment, and to attain the 2008 ozone NAAQS in San Diego County by that year. Table 7—Summary of San Diego County 2008 Ozone NAAQS Attainment Demonstration [Summer planning inventory, tpd] Row NO X VOC A 2011 Base Year Emissions Level a 126.5 137.5 B 2026 Attainment Year Baseline Emissions Level b 72.2 100.8 C 2026 Modeled Attainment Emissions Level c 72.2 100.8 D Total Reductions Needed from 2011 Levels to Demonstrate Attainment (A−C) 54.3 36.7 E Reductions from Baseline ( i.e., adopted) Measures, net of growth, growth increment for military and SDIA, ERC set-aside and EMFAC2017 Adjustment Factors adjustment (A−B) 54.3 36.7 F Reductions from District's Aggregate Emissions Reduction Commitment from 2020 Plan 0 0 G Reductions from CARB's Aggregate Emissions Reduction Commitment from 2016 State Strategy 0 0 H Total Reductions from District's and CARB's Commitments 0 0 I Total Reductions from Baseline Measures and the District's and CARB's Commitments (E + H) 54.3 36.7 J 2026 Emissions with Reductions from Control Strategy (A−I) 72.2 100.8 Attainment demonstrated? Yes Yes a See Table 1 of this document. Includes emissions out to 100 NM from the coast. b See Table 1 of this document. Includes emissions out to 100 NM from the coast. Year 2026 baseline emissions reflect area-wide growth, the growth increments for the military and SDIA, the District's ERC set-aside and the EMFAC2017 Adjustment Factors adjustment. c 2020 Plan, Section 3.3.4. Table 8 of this document summarizes the attainment demonstration for the 2015 ozone NAAQS by listing the 2017 base year emissions level, the attainment year (2032) baseline emissions level, the modeled attainment (2032) emissions level, and the reductions that the District and CARB estimate will be achieved through implementation of baseline ( i.e., adopted) measures taking into account area-wide growth, the growth increments for the military and SDIA, the District's ERC set-aside and the EMFAC2017 Adjustment Factors adjustment. Table 8 also shows the aggregate emissions reductions commitments (for year 2032) made by the District and CARB as part of the control strategy for attainment of the 2015 ozone NAAQS in San Diego County. As shown in Table 8, baseline measures are expected to reduce base year (2017) emissions of NO X by 27 percent and VOC emissions by 14 percent by the 2032 attainment year, notwithstanding area-wide growth, the growth increments for the military and SDIA, the District's ERC set-aside and the EMFAC2017 Adjustment Factors adjustment. The District's and CARB's commitments would further reduce emissions of NO X by 2032 by an additional 5.7 tpd. Together, the baseline emissions reductions and the NO X emissions reduction commitments would provide for attainment of the 2015 ozone NAAQS by the attainment year (2032). Table 8—Summary of San Diego County 2015 Ozone NAAQS Attainment Demonstration [Summer planning inventory, tpd] Row NO X VOC A 2017 Base Year Emissions Level a 94.5 113.8 B 2032 Attainment Year Baseline Emissions Level b 69.0 98.3 C 2032 Modeled Attainment Emissions Level c 63.3 98.3 D Total Reductions Needed from 2017 Levels to Demonstrate Attainment (A−C) 31.0 15.5 E Reductions from Baseline ( i.e., adopted) Measures, net of growth, growth increment for military and SDIA, ERC set-aside and EMFAC2017 Adjustment Factors adjustment (A−B) 25.5 15.5 F Reductions from District's Aggregate Emissions Reduction Commitment from 2020 Plan 1.7 0 G Reductions from CARB's Aggregate Emissions Reduction Commitment from 2016 State Strategy 4.0 0 H Total Reductions from District's and CARB's Commitments 5.7 0 I Total Reductions from Baseline Measures and the District's and CARB's Commitments (E + H) 31.2 15.5 J 2032 Emissions with Reductions from Control Strategy (A−I) 63.3 98.3 Attainment demonstrated? Yes Yes a See Table 1 of this document. Includes emissions out to 100 NM from the coast. b See Table 1 of this document. Includes emissions out to 100 NM from the coast. Year 2032 [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%3A2023-27513. Public record. Not legal advice.