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 Environmental Protection Agency 40 CFR Part 52
[EPA-R09-OAR-2024-0472; FRL-12322-01-R9]
 AGENCY: Environmental Protection Agency (EPA).
 ACTION: Proposed rule.
 SUMMARY: The Environmental Protection Agency (EPA) is proposing to make a clean data determination (CDD) for the Los Angeles-South Coast Air Basin (“South Coast”) air quality planning area in California based on our determination that the area is attaining the 2006 fine particle (PM2.5) National Ambient Air Quality Standards (NAAQS). If we finalize this CDD, certain Clean Air Act (CAA) requirements that apply to the South Coast Air Quality Management District (SCAQMD or “District”) will be suspended for so long as the area continues to meet the 2006 24-hour PM2.5
                         NAAQS. The EPA is also proposing to approve a revision to California's state implementation plan (SIP) consisting of the 2018 base year emissions inventory for the South Coast PM2.5
                         nonattainment area, submitted by the California Air Resources Board (CARB) on December 29, 2020. We are taking comments on this proposal and plan to follow with a final action.
 DATES: Comments must be received on or before December 26, 2024.
 ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R09-OAR-2024-0472 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 a disability 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: Ashley Graham, Geographic Strategies and Modeling Section (AIR-2-2), EPA Region IX, 75 Hawthorne Street, San Francisco, CA 94105; phone: (415) 972-3877; email: 
                        *graham.ashleyr@epa.gov.*


SUPPLEMENTARY INFORMATION: Throughout this document, “we,” “us,” and “our” refer to the EPA. Table of Contents I. Background A. PM2.5
                         NAAQS B. South Coast PM2.5
                         Designations, Classifications, and SIP Revisions C. Clean Air Act Requirements for PM2.5
                         Nonattainment Areas That Fail To Attain by the Serious Area Attainment Date D. The EPA's Clean Data Policy II. The EPA's Proposed Clean Data Determination A. Monitoring Network Review, Quality Assurance, and Data Completeness B. The EPA's Evaluation of Attainment III. Review of the 2018 Base Year Emissions Inventory in the South Coast PM2.5
                         Plan A. Statutory and Regulatory Requirements B. Base Year Emissions Inventory in the Plan C. The EPA's Evaluation IV. Environmental Justice Considerations V. The EPA's Proposed Action VI. Statutory and Executive Order Reviews I. Background A. PM*2.5*
                     NAAQS Under section 109 of the CAA, the EPA has established NAAQS for certain pervasive air pollutants (referred to as “criteria pollutants”) and conducts periodic reviews of the NAAQS to determine whether the EPA should revise or establish new NAAQS to protect public health. The EPA first established annual and 24-hour NAAQS for PM2.5
                     on July 18, 1997.[1]
                    
                     The 24-hour primary and secondary standards were set at 65 μg/m[3]
                     based on the three-year average of the 98th percentile of 24-hour PM2.5
                     concentrations at each monitoring site within an area.[2]
                    
                     On September 21, 2006, the EPA strengthened the 24-hour PM2.5
                     NAAQS to provide increased protection of public health, revising the level of the standard to 35 μg/m[3]
                    .[3]
                    
                     Since then, the EPA has also revised the level of the primary annual PM2.5
                     NAAQS, which is currently set at 9.0 μg/m[3]
                    .[4] The EPA established each of the PM2.5
                     NAAQS after considering substantial evidence from numerous health studies demonstrating that serious health effects are associated with exposures to PM2.5
                     concentrations above these levels. Epidemiological studies have shown statistically significant correlations 
                    ( print page 92874)
                    between elevated PM2.5
                     levels and premature mortality. Other important health effects associated with PM2.5
                     exposure include aggravation of respiratory and cardiovascular disease (as indicated by increased hospital admissions, emergency room visits, absences from school or work, and restricted activity dates), changes in lung function and increased respiratory symptoms, and new evidence for more subtle indicators of cardiovascular health. Individuals particularly sensitive to PM2.5
                     exposure include older adults, people with heart and lung disease, and children.[5] PM2.5
                     can be particles emitted by sources directly into the atmosphere as a solid or liquid particle (“primary PM2.5
                    ” or “direct PM2.5
                    ”) or can be particles that form in the atmosphere as a result of various chemical reactions from PM2.5
                     precursor emissions emitted by sources (“secondary PM2.5
                    ”). The EPA has identified the precursors of PM2.5
                     to be oxides of nitrogen (“NOX
                    ”), sulfur oxides (“SOX
                    ”), volatile organic compounds (“VOC”), and ammonia.[6] B. South Coast PM*2.5*
                     Designations, Classifications, and SIP Revisions The South Coast PM2.5
                     nonattainment area is home to approximately 17 million people, has a diverse economic base, and contains one of the highest-volume port areas in the world. For a precise description of the geographic boundaries of the South Coast PM2.5
                     nonattainment area, see 40 CFR 81.305. The local air district with primary responsibility for developing a plan to attain the 2006 24-hour PM2.5
                     NAAQS in this area is the SCAQMD. The District works cooperatively with CARB in preparing these plans. Authority for regulating sources in the South Coast is split between the District, which has responsibility for regulating stationary and most area sources, and CARB, which has responsibility for regulating most mobile sources and some categories of consumer products. Following promulgation of a new or revised NAAQS, the EPA is required by CAA section 107(d) to designate areas throughout the nation as attaining or not attaining the NAAQS. Effective December 14, 2009, the EPA designated the South Coast as nonattainment for the 2006 24-hour PM2.5
                     standards.[7]
                    
                     On June 2, 2014, the EPA classified the South Coast area as “Moderate” nonattainment for the 2006 24-hour PM2.5
                     NAAQS under subpart 4 of part D, title I of the Act.[8] On January 13, 2016, the EPA reclassified the South Coast area as a “Serious” nonattainment area based on our determination that the area could not practicably attain the 2006 24-hour PM2.5
                     NAAQS by the area's December 31, 2015 attainment date.[9]
                    
                     As a consequence, California was required to submit a nonattainment new source review program revision and a Serious area attainment plan, including a demonstration that the plan provides for attainment of the 2006 24-hour PM2.5
                     NAAQS in the South Coast as expeditiously as practicable but no later than December 31, 2019, which is the latest permissible attainment date under CAA section 188(c)(2).[10]
                    
                     California submitted a plan addressing the Serious area attainment planning requirements for the 2006 24-hour PM2.5
                     NAAQS in the South Coast on April 27, 2017,[11]
                    
                     and the EPA approved the Serious area plan on February 12, 2019.[12] Effective October 16, 2020, the EPA determined, based on air quality monitoring data from 2017 through 2019, that the South Coast nonattainment area failed to attain the 2006 24-hour PM2.5
                     NAAQS by the December 31, 2019 Serious area attainment date.[13]
                    
                     As a result of this determination, California was required to submit a revision to the California SIP that, among other elements, provided for a five percent annual reduction in emissions of direct PM2.5
                     or a PM2.5
                     plan precursor pollutant. In accordance with sections 179(d)(3) and 172(a)(2) of the CAA and 40 CFR 51.1004(a)(3), the revised plan was required to demonstrate attainment of these NAAQS as expeditiously as practicable and no later than 5 years from the effective date of the EPA's prior determination that the area failed to attain (
                    *i.e.,*
                     by October 16, 2025), except that the EPA may extend the attainment date to a date no later than 10 years from the effective date of this determination (
                    *i.e.,*
                     to October 16, 2030), “considering the severity of nonattainment and the availability and feasibility of pollution control measures.” [14] On December 29, 2020, California submitted to the EPA the “Final South Coast Air Basin Attainment Plan for 2006 24-hour PM2.5
                     Standard,” (“South Coast PM2.5
                     Plan” or “Plan”) adopted by SCAQMD on December 4, 2020, and adopted by CARB on December 21, 2020.[15 16]
                     The PM2.5
                     Plan was intended to address the requirements resulting from the September 16, 2020 finding of failure to attain and included the State's demonstration that the South Coast Air Basin would attain the 2006 24-hour PM2.5
                     NAAQS by December 31, 2023.[17]
                    
                     As part of this action, as discussed in Section III of this document, the EPA is proposing to approve the base year emissions inventory in the South Coast PM2.5
                     Plan as meeting the requirements of CAA section 172(c)(3) and 40 CFR 51.1008(c)(1). The EPA is not proposing action on the remaining elements of the Plan and will do so through subsequent rulemaking, as appropriate. C. Clean Air Act Requirements for PM*2.5*
                     Nonattainment Areas That Fail To Attain by the Serious Area Attainment Date The general CAA part D nonattainment area planning requirements are found in subpart 1 and the nonattainment area planning requirements specific to particulate matter are found in subpart 4. The subpart 1 statutory requirements for attainment plans include the following: the section 172(c)(1) requirements for reasonably available control measures (RACM)/reasonably available control technology and attainment demonstrations; the section 172(c)(2) requirement to demonstrate reasonable further progress (RFP); the section 172(c)(3) requirement for emissions inventories; the section 172(c)(5) requirements for a nonattainment new source review permitting program; and the section 172(c)(9) requirement for contingency measures. The more specific subpart 4 statutory requirements for a Serious PM2.5
                     nonattainment area that has failed to attain the PM2.5
                     NAAQS by the applicable attainment date, such as the South Coast area, include the requirements under CAA section 189(d) that the State submit an attainment plan revision that, among other things, demonstrates expeditious attainment of the NAAQS within the time period provided under CAA section 179(d)(3) and provides for annual reductions in emissions of direct PM2.5
                     or a PM2.5
                     plan 
                    ( print page 92875)
                    precursor pollutant within the area of not less than five percent per year from the most recent emissions inventory for the area until attainment.[18] In addition to the requirement to submit control measures providing for a five percent reduction in emissions of certain pollutants on an annual basis, the EPA interprets CAA section 189(d) as requiring a state to submit an attainment plan that includes the same basic statutory plan elements that are required for other attainment plans.[19]
                    
                     Specifically, such plan submission must include a comprehensive, accurate, current inventory of actual emissions from all sources of PM2.5
                     and PM2.5
                     precursors in the area, and must address requirements for an attainment plan control strategy, attainment demonstration, reasonable further progress, quantitative milestones, contingency measures, and nonattainment new source review.[20] To support implementation of the PM2.5
                     NAAQS, the EPA promulgated the “Fine Particle Matter National Ambient Air Quality Standard: State Implementation Plan Requirements; Final Rule” (“PM2.5
                     Implementation Rule”).[21]
                    
                     The PM2.5
                     Implementation Rule provides additional regulatory requirements and interpretive guidance on the statutory SIP requirements that apply to areas designated nonattainment for the PM2.5
                     NAAQS, including the 2006 24-hour PM2.5
                     NAAQS at issue in this proposal. D. The EPA's Clean Data Policy Under the EPA's longstanding Clean Data Policy, which was reaffirmed in the PM2.5
                     Implementation Rule at 40 CFR 51.1015, when an area has attained the relevant PM2.5
                     standard(s), the EPA may issue a CDD (also sometimes referred to as a determination of attainment for the purposes of the Clean Data Policy) after notice and comment rulemaking determining that a specific area is attaining the relevant standard(s). A CDD is not linked to any particular attainment deadline and is not necessarily equivalent to a determination that an area has attained the standard by its applicable attainment deadline. The effect of a CDD is to suspend the requirement for the area to submit an attainment demonstration, RACM, an RFP plan, contingency measures, and any other planning requirements related to attainment for as long as the area continues to attain the standard.[22]
                    
                     With respect to the attainment demonstration requirements of section 189(d) of the CAA, the EPA finds that if an area already has air quality monitoring data demonstrating attainment of the standard, under the Clean Data Policy, there is no need for the area to make a further submittal containing additional measures to achieve attainment, nor is there a need for the area to perform future modeling to show how the area will achieve attainment.[23]
                    
                     Similarly, the EPA interprets the CAA as not requiring the submittal of RFP and associated quantitative milestones for areas that are already attaining the NAAQS. For areas that are attaining the NAAQS, showing that the state will make RFP towards attainment has no meaning. Similar reasoning applies to other SIP submittal requirements that are linked with attainment demonstration and RFP requirements. The EPA interprets the obligation to submit contingency measures as suspended when the area has attained the standard because those contingency measures are directed at ensuring RFP and attainment by the applicable date. A CDD does not suspend the requirements for an emissions inventory or for new source review.[24] II. The EPA's Proposed Clean Data Determination A. Monitoring Network Review, Quality Assurance, and Data Completeness A determination of attainment under the EPA's Clean Data Policy is typically based upon complete, quality-assured data gathered at established State and Local Air Monitoring Stations (SLAMS) in a nonattainment area and entered into the EPA's Air Quality System (AQS) database. Data from ambient air monitors operated by state/local agencies in compliance with the EPA monitoring requirements must be submitted to AQS. Monitoring agencies annually certify that these data are accurate to the best of their knowledge. Accordingly, the EPA relies primarily on data in AQS when determining compliance with the NAAQS.[25]
                    
                     The EPA reviews all data to determine the area's air quality status in accordance with 40 CFR part 50, appendix N. Under EPA regulations in 40 CFR 50.13 and in accordance with appendix N, the 2006 24-hour PM2.5
                     NAAQS are met when the 98th percentile 24-hour concentration, as determined in accordance with the rounding conventions in 40 CFR part 50, appendix N, is less than or equal to 35 μg/m3
                     at each eligible monitoring site within the area. Section 110(a)(2)(B)(i) of the CAA requires states to establish and operate air monitoring networks to compile data on ambient air quality for all criteria pollutants. The monitoring requirements are specified in 40 CFR part 58. These requirements are applicable to state, and where delegated, local air monitoring agencies that operate criteria pollutant monitors. The regulations in 40 CFR part 58 establish specific requirements for operating air quality surveillance networks to measure ambient concentrations of PM2.5, including requirements for measurement methods, network design, quality assurance procedures, and in the case of large urban areas, the minimum number of monitoring sites designated as SLAMS. In section 4.7 of appendix D to 40 CFR part 58, the EPA specifies minimum monitoring requirements for PM2.5
                     to operate at SLAMS. SLAMS produce data comparable to the NAAQS, and therefore, the monitor must be an approved federal reference method (FRM) or federal equivalent method (FEM). The minimum number of SLAMS required is described in section 4.7.1 and can be met by either filter-based or continuous FRMs or FEMs. The monitoring regulations also provide that each core-based statistical area must operate a minimum number of PM2.5
                     continuous monitors; [26]
                    
                     however, this requirement can be met by either an FEM or a non-FEM continuous monitor, and the continuous monitors can be located with other SLAMS or at a different location. Consequently, the monitoring requirements for PM2.5
                     can be met with filter-based FRMs/FEMs, continuous FEMs, continuous non-FEMs, or a 
                    ( print page 92876)
                    combination of monitors at each required SLAMS. Under 40 CFR 58.10, states are required to submit annual monitoring network plans to the EPA.[27]
                    
                     Within the South Coast Air Basin, the District and the Pechanga Band of Indians (“Pechanga Band”) are the agencies responsible for assuring that the area meets PM2.5
                     air quality monitoring requirements. The District submits annual monitoring network plans (ANPs) to the EPA that describe the various monitoring sites operated by the District. The Pechanga Band does the same for the monitoring site it operates. These plans discuss the status of the air monitoring network, as required under 40 CFR 58.10. Each year, the EPA reviews these ANPs for compliance with the applicable monitoring requirements in 40 CFR part 58. The EPA approved those portions of the District's 2023 ANP [28]
                    
                     and the Pechanga Band's 2023 ANP [29]
                    
                     that pertain to the adequacy of the network for PM2.5
                     monitoring purposes. During the 2021-2023 period, ambient PM2.5
                     concentration data that are eligible for use in determining whether an area has attained the PM2.5
                     NAAQS were collected at a total of 19 sites within the South Coast. The District operates 18 of these sites while the Pechanga Band operates 1 of these sites. All of the sites are designated SLAMS for PM2.5
                    .[30]
                    
                     Based on our review of the PM2.5
                     monitoring network, we propose to find that the monitoring network in the South Coast is adequate for the purpose of collecting ambient PM2.5
                     concentration data for use in determining whether the South Coast has attained the 2006 24-hour PM2.5
                     NAAQS. Under 40 CFR 58.15, monitoring agencies must submit a letter to the EPA each year to certify that all of the ambient concentration and quality assurance data for the previous year have been submitted to AQS and that the ambient concentration data are accurate to the best of their knowledge, taking into consideration the quality assurance findings. The letter must address data for all FRM and FEM monitors at SLAMS and special purpose monitoring stations that meet the criteria specified in 40 CFR 58, appendix A. The District [31]
                    
                     and the Pechanga Band [32]
                    
                     submit this certification annually, as required by 40 CFR 58.15. With respect to data completeness, we determined that the data collected by the District met the quarterly completeness criterion for all 12 quarters of the three-year period at most of the PM2.5
                     monitoring sites in the South Coast. The Pechanga Band, as of proposal, did not meet the quarterly completeness criterion for all 12 quarters of the three-year period at its PM2.5
                     monitoring site. More specifically, among the 19 PM2.5
                     monitoring sites from which regulatory data are available, the data from six of the sites did not meet the 75 percent completeness criterion for at least one quarter in the 2021-2023 period, leading to invalid 2023 design values. Of the six sites with invalid design values, two sites, Long Beach (North) and Long Beach (South), were approved for closure by the EPA and ceased operating at the end of the second quarter in 2022 and the end of the first quarter in 2022, respectively.[33 34]
                     The Signal Hill (Lbsh) site began monitoring for PM2.5
                     in the second quarter of 2022 and was complete for three quarters in 2022 and all four quarters of 2023. Two other sites, Azusa and Mission Viejo, temporarily ceased operating in 2022. The Azusa site was incomplete in the second and third quarter of 2022 and temporarily ceased monitoring at the end of the third quarter in 2022. The Mission Viejo site temporarily ceased operations during the second quarter of 2022. At the time this document was being prepared, the remaining site, Pechanga, operated by the Pechanga Band had yet to fully upload and certify their 2023 data. The invalid design values from the six monitors described above are from sites within the South Coast that generally measure lower 24-hour design values than other monitors in the South Coast. Given that the District and the Pechanga Band operate more than the minimum number of PM2.5
                     monitoring sites in the Los Angeles-Long Beach-Anaheim, CA metropolitan statistical area (MSA) and the Riverside-San Bernardino-Ontario, CA MSA, the overall completeness of data from all sites, especially those sites that historically measure the highest concentrations in the South Coast, we find that the data set compiled from the PM2.5
                     monitoring networks is sufficient for the purposes of determining whether the South Coast has attained the 2006 24-hour PM2.5
                     NAAQS.[35] Finally, the EPA conducts regular technical systems audits (TSAs) where we review and inspect state and local ambient air monitoring programs to assess compliance with applicable regulations concerning the collection, analysis, validation, and reporting of ambient air quality data. For the purposes of this proposal, we reviewed the findings from the EPA's most recent TSAs of the District's [36]
                    
                     and the Pechanga Band's [37]
                    
                     ambient air monitoring programs. The results of the TSAs do not preclude the EPA from determining that the South Coast PM2.5
                     nonattainment area has attained the 2006 24-hour PM2.5
                     NAAQS. In summary, based on the EPA's reviews of the relevant ANPs, certifications, quality assurance data, and TSAs, we propose to find that the PM2.5
                     data collected at the South Coast Air Basin monitoring sites are suitable for determining whether the South Coast PM2.5
                     nonattainment area is attaining the 2006 24-hour PM2.5
                     NAAQS. B. The EPA's Evaluation of Attainment Table 1 provides the PM2.5
                     design values at each of the 19 monitoring sites with the South Coast PM2.5
                     nonattainment area, expressed as a single design value representing the 2021-2023 period and for each individual year. The PM2.5
                     data show that the design values at the South Coast Air Basin monitoring sites were below 
                    ( print page 92877)
                    the 2006 24-hour PM2.5
                     NAAQS of 35 μg/m3
                    . Table 1—2021-2023 24-Hour PM
                        2.5
                         Design Values for the South Coast PM
                        2.5
                         Nonattainment Area
General location
Site
                             (AQS ID)
Annual 98th percentile
                             
                                (μg/m3
                                )
2021-2023
                             24-hour 
                             design value 
                             
                                (μg/m3
                                )2021
2022
2023**Los Angeles County**East San Gabriel Valley
Azusa (06-037-0002)
36.1
17.8 (Inc)
No Data (Inc)
27 (Inv).Central Los Angeles
Los Angeles (Main Street) (06-037-1103)
45.2
21.9
23.4
30.West San Fernando Valley
Reseda (06-037-1201)
36.1
19.5
19.2
25.South Central Los Angeles County
Compton (06-037-1302)
42.5
32.6
28.1
34.South San Gabriel Valley
Pico Rivera #2 (06-037-1602)
47.9
25.6
27.8
34.West San Gabriel Valley
Pasadena (06-037-2005)
29.9
19.0
17.7
22.South Coastal Los Angeles County
Long Beach (North) (06-037-4002)
31.2
18.0 (Inc)
No Data (Inc)
25 (Inv).South Coastal Los Angeles County
South Long Beach (06-037-4004)
32.8
23.1 (Inc)
No Data (Inc)
28 (Inv).South Coastal Los Angeles County
Long Beach-Route 710 Near Road (06-037-4008)
34.8
25.5
25.4
29.South Coastal Los Angeles County
Signal Hill (Lbsh) (06-037-4009)
No Data (Inc)
19.3 (Inc)
22.3
21 (Inv).**Orange County**Central Orange County
Anaheim (06-059-0007)
37.1
22.1
22.6
27.Saddleback Valley
Mission Viejo (06-059-2022)
24.9
16.9 (Inc)
No Data (Inc)
21 (Inv).**Riverside County**Temecula Valley
Pechanga (06-065-0009)
16.5
11.4
12.0 (Inc)
13 (Inv).Metropolitan Riverside County
Rubidoux (06-065-8001)
37.5
23.2
24.5
28.Mira Loma
Mira Loma (Van Buren) (06-065-8005)
42.8
26.2
30.2
33.**San Bernardino County**Southwest San Bernardino Valley
Ontario-Route 60 Near Road (06-071-0027)
49.4
26.4
26.4
34.Central San Bernardino Valley
Fontana (06-071-2002)
33.4
28.1
25.0
29.East San Bernardino Mountains
Big Bear (06-071-8001)
21.5
23.2
18.0
21.Central San Bernardino Valley
San Bernardino (06-071-9004)
34.2
25.8
21.8
27.Source: EPA, AQS Design Value Report (AMP480), Report Request ID: 2218164, August 23, 2024.**Notes:**
                         Inc = Incomplete Data. Inv = Invalid design values due to incomplete data.
 Preliminary data available in AQS for 2024 (January through June) indicate that the South Coast area continues to show concentrations below the 2006 24-hour PM2.5
                     NAAQS.[38]
                    
                     Consequently, the EPA is proposing to determine based upon three years of complete, quality-assured, and certified data from 2021 through 2023 that the South Coast PM2.5
                     nonattainment area has attained the 2006 24-hour PM2.5
                     NAAQS and to issue a CDD. If we finalize this proposed CDD, the requirements for the State to submit an attainment demonstration, an RFP plan, quantitative milestones and quantitative milestone reports, and contingency measures for the area will be suspended until such time as: (1) the area is redesignated to attainment, after which such requirements are permanently discharged; or, (2) the EPA determines that the area has re-violated the 24-hour PM2.5
                     NAAQS, after which time the state shall submit such attainment plan elements for the Serious nonattainment area by a future date to be determined by the EPA and announced through publication in the 
                    **Federal Register**
                     at the time the EPA determines the area is violating the 24-hour PM2.5
                     NAAQS.[39] A CDD does not suspend the requirements for an emissions inventory. As discussed in Section III of this document, this document includes our proposed approval of the 2018 base year emissions inventory included in the attainment plan for the South Coast PM2.5
                     nonattainment area, submitted on December 29, 2020. III. Review of the 2018 Base Year Emissions Inventory in the South Coast PM
                    2.5
                     Plan A. Statutory and Regulatory Requirements 1. Requirements for Emissions Inventories CAA section 172(c)(3) requires that each nonattainment plan SIP submission include a comprehensive, accurate, current inventory of actual emissions from all sources of the relevant pollutant or pollutants in the nonattainment area. The EPA discussed the emissions inventory requirements that apply to PM2.5
                     nonattainment areas in the PM2.5
                     SIP Requirements Rule and 
                    ( print page 92878)
                    codified these requirements in 40 CFR 51.1008.[40]
                    
                     The EPA has also issued guidance concerning emissions inventories for PM2.5
                     nonattainment areas.[41] The base year emissions inventory for an attainment plan under CAA section 189(d) must provide a state's best estimate of actual emissions from all sources of the relevant pollutants in the area (
                    *i.e.,*
                     all emissions that contribute to the formation of a particular NAAQS pollutant). For the PM2.5
                     NAAQS, the base year inventory must include direct PM2.5
                     emissions, separately reported filterable and condensable PM2.5
                     emissions,[42]
                    
                     and emissions of all chemical precursors to the formation of secondary PM2.5
                     (
                    *i.e.,*
                     NOX, SO2
                    , VOC, and ammonia).[43] The emissions inventory base year for a Serious PM2.5
                     nonattainment area subject to CAA section 189(d) must be one of the three years for which the EPA used monitored data to determine that the area failed to attain the PM2.5
                     NAAQS by the applicable Serious area attainment date, or another technically appropriate year justified by the state in its Serious area SIP submission.[44] A state's nonattainment plan SIP submission must include documentation explaining how it calculated emissions data for the inventory. In estimating mobile source emissions, a state should use the latest emissions models and planning assumptions available at the time the SIP is developed. At the time the South Coast PM2.5
                     Plan was developed, the latest EPA-approved version of California's mobile source emissions factor model for estimating tailpipe, brake and tire wear emissions from on-road mobile sources was EMFAC2017.[45]
                    
                     States are also required to use the EPA's “Compilation of Air Pollutant Emission Factors” (AP-42) road dust method for calculating re-entrained road dust emissions from paved roads.[46] 2. Procedural Requirements for SIPs and SIP Revisions CAA sections 110(a)(1) and (2) and 110(l) require each state to provide reasonable public notice and opportunity for public hearing prior to the adoption and submission of a SIP or SIP revision to the EPA. To meet this requirement, every SIP submission should include evidence that the State provided adequate public notice and an opportunity for a public hearing consistent with the EPA's implementing regulations in 40 CFR 51.102. The District provided a public comment period and held a public hearing prior to the adoption of the South Coast PM2.5
                     Plan on October 7, 2020.[47]
                    
                     The SIP submission includes proof of publication of notices for the District's public hearing. Therefore, we find that the South Coast PM2.5
                     Plan meets the procedural requirements for public notice and hearing in CAA sections 110(a) and 110(l). CAA section 110(k)(1)(B) requires the EPA to determine whether a SIP submittal is complete within 60 days of receipt. This section of the CAA also provides that any plan that the EPA has not affirmatively determined to be complete or incomplete will become complete by operation of law six months after the date of submittal. The EPA's SIP completeness criteria are found in 40 CFR part 51, appendix V. On June 29, 2021, the South Coast PM2.5
                     Plan was deemed complete by operation of law under CAA section 110(k)(1)(B). B. Base Year Emissions Inventory in the Plan The annual average planning emissions inventories for direct PM2.5
                     and all PM2.5
                     precursors (NOX, SOX, VOC, and ammonia) for the South Coast PM2.5
                     nonattainment area, together with documentation for the inventories, are included in Chapter 3 (“Base-Year and Future Emissions”) of the Plan. More detailed emissions inventories for the South Coast PM2.5
                     nonattainment area are included in appendix I (“Emissions Inventory”) of the Plan. Each emissions inventory is divided into two source classifications: Stationary sources (
                    *i.e.,*
                     point sources and area sources) and mobile sources (
                    *i.e.,*
                     on-road and off-road sources). Point sources in the South Coast Air Basin that emit four tons per year (tpy) or more of PM, NOX, SOX
                    , or VOC report annual emissions to the District. Point source emissions for the 2018 base year emissions inventory are generally based on reported data from facilities using the District's Annual Emissions Reporting program.[48]
                    
                     Area sources include small emissions sources distributed across the nonattainment area. CARB and the District estimate emissions for about 400 area source categories using established inventory methods, including publicly available emissions factors and activity information. Activity data may come from national survey data such as from the Energy Information Administration or from local sources such as the Southern California Gas Company, paint suppliers, and District databases. Emissions factors can be based on a number of sources including source tests, compliance reports, and the EPA's AP-42. On-road emissions inventories are calculated using CARB's EMFAC2017 model and the travel activity data provided by the Southern California Association of Governments (SCAG) in “The 2016-2040 Regional Transportation Plan/Sustainable Communities Strategy.” [49]
                    
                     CARB used the Spatial and Temporal Allocator tool to distribute emissions spatially and temporally.[50] 
 
 CARB provided emissions inventories for off-road equipment, which includes construction and mining equipment, industrial and commercial equipment, lawn and garden equipment, locomotives, aircraft, tractors, harbor craft, off-road recreational vehicles, construction equipment, forklifts, cargo handling equipment, and various other mobile equipment types. CARB uses several models to estimate emissions for more than one hundred off-road equipment categories.[51] Finally, the South Coast PM2.5
                     Plan provides separate estimates of filterable and condensable PM2.5
                     emissions, expressed as annual average PM2.5
                     emissions, for all of the identified source categories for the 2018 base year, as well as subsequent relevant years.[52] Table 2 provides a summary of the annual average inventories in tons per day (tpd) of direct PM2.5
                     and PM2.5
                     precursors for the 2018 base year. For a detailed breakdown of the inventories, see Chapter 3 and appendix I of the South Coast PM2.5
                     Plan. Table 2—Summary of Emissions by Major Source Category in the South Coast Air Basin: 2018 Base Year Average Annual Day
[tpd] a
Source category
Direct PM
                            2.5
NO
                            X
SO
                            X
VOC
AmmoniaStationary Sources
44.8
57.7
8.2
206.8
58.6On-Road Mobile
11.4
177.9
1.7
81.6
14.2Off-Road Mobile
6.3
134.9
4.1
80.8
0.2Total
62.4
370.5
14.0
369.2
72.9a
                         Values may not sum due to rounding.Source: South Coast PM
                        2.5
                         Plan, Chapter 3, Table 3-1.
 C. The EPA's Evaluation The inventories in the South Coast PM2.5
                     Plan are based on the most current and accurate information available to the State and District at the time the Plan and its inventories were being developed, including the latest EPA-approved version of California's mobile source emissions model that was available to the State and District at the time they were developing the Plan, EMFAC2017. The inventories comprehensively address all source categories in the South Coast PM2.5
                     nonattainment area and were developed consistent with the EPA's regulations and inventory guidance. In accordance with 40 CFR 51.1008(c)(1), the 2018 base year is one of the three years for which monitored data were used to determine that the area failed to attain the 2006 24-hour PM2.5
                     NAAQS by the applicable Serious area attainment date, and it represents actual annual average emissions of all sources within the nonattainment area. Direct PM2.5
                     and all PM2.5
                     precursors are included in the inventories, and filterable and condensable direct PM2.5
                     emissions are identified separately. For these reasons, we are proposing to approve the 2018 base year emissions inventory in the South Coast PM2.5
                     Plan as meeting the requirements of CAA section 172(c)(3) and 40 CFR 51.1008(c)(1). IV. Environmental Justice Considerations To identify environmental burdens and susceptible populations in underserved communities in the South Coast PM2.5
                     nonattainment area and to better understand the context of the proposed CDD and approval of the base year emissions inventory on these communities, we conducted a screening-level analysis using the EPA's environmental justice (EJ) screening and mapping tool (“EJSCREEN”).[53]
                     [54]
                    
                     The results of this analysis are being provided for informational and transparency purposes. Our screening-level analysis indicates that communities affected by this action rank above the national average for the EJSCREEN “Demographic Index,” which is the average of an area's percent low income and percent people of color populations, 
                    *i.e.,*
                     the two demographic indicators explicitly named in Executive Order 12898 on EJ.[55]
                    
                     These communities also rank above the national average for the “Limited English Speaking Households,” and “Less Than High School Education” indicators. Although the area is attaining the PM2.5
                     NAAQS, because almost all areas across the U.S. are also attaining the NAAQS (some by a wider margin), communities within the South Coast PM2.5
                     nonattainment area rank above the national average for the “Particulate Matter 2.5 (μg/m3
                    )” environmental burden indicator. These communities also score above the national average for other environmental burden indicators, including the “Ozone (ppb),” “Nitrogen Dioxide (NO2) (ppbv),” and “Traffic Proximity (daily traffic count/distance to road)” indicators. As discussed in the EPA's EJ technical guidance, people of color and low-income populations, such as those in the South Coast Air Basin, often experience greater exposure and disease burdens than the general population, which can increase their susceptibility to adverse health effects from environmental stressors.[56]
                    
                     Underserved communities may have a compromised ability to cope with or recover from such exposures due to a range of physical, chemical, biological, social, and cultural factors.[57] 
 
 Notwithstanding the EJ concerns highlighted by the results of the EJSCREEN analysis, because monitoring data indicate the area has attained the 2006 24-hour PM2.5
                     NAAQS, we expect that this action will generally have neutral environmental and health impacts on all populations in the South Coast Air Basin, including communities with EJ concerns. At a minimum, this action would not worsen existing air quality and there is no information in the record indicating that this action is expected to have disproportionately high or adverse human health or environmental effects on a particular group of people. Our final action on the base year emissions inventory will fulfill our statutory obligation to act on a portion of a SIP submittal under section 110(k)(3). If we finalize our proposed CDD, requirements related to achieving attainment of the 2006 24-hour PM2.5
                     NAAQS will be suspended. Because the area has attained the standard, such requirements are not necessary for timely attainment of the NAAQS. However, if prior to a potential future redesignation to attainment we determine the South Coast PM2.5
                     nonattainment area subsequently violates the NAAQS, we will rescind the CDD and any unfulfilled attainment planning requirements will apply once again to the area.[58]
                    
                     Furthermore, notwithstanding the suspension of certain attainment-related requirements, all requirements adopted into the SIP prior to attainment will remain in place.[59] The EPA notes that there are other efforts underway to reduce environmental burdens in the South Coast Air Basin. The South Coast Air Basin is designated nonattainment for the 2012 annual PM2.5
                     NAAQS and on June 27, 2024, CARB adopted a revised attainment plan which includes, among other things, the State's control strategy to achieve reductions in direct PM2.5
                     and PM2.5
                     precursors to bring the area into attainment of those NAAQS.[60]
                    
                     Additionally, on July 22, 2024, the EPA announced the selection of the SCAQMD to receive a Climate Pollution Reduction Grant of approximately $500 million to implement community-driven solutions to address the climate crisis, reduce air pollution, advance environmental justice, and accelerate America's clean energy transition.[61]
                    
                     Furthermore, on October 29, 2024, the U.S. EPA announced the selection of the Los Angeles Harbor Department to receive a Clean Ports Program—Zero-Emission Technology Deployment Grant of approximately $400 million to fund zero-emission port equipment and infrastructure to reduce mobile source emissions.[62]
                    
                     These efforts are expected to result in further reductions in direct PM2.5
                     and PM2.5
                     precursor emissions and to relieve some of the cumulative burden on disadvantaged communities in the South Coast PM2.5
                     nonattainment area. V. The EPA's Proposed Action The EPA is proposing to determine, based on the most recent three years (2021-2023) of complete (or otherwise validated), quality-assured, and certified data meeting the requirements of 40 CFR part 50, appendix N, that the South Coast PM2.5
                     nonattainment area has attained the 2006 24-hour PM2.5
                     NAAQS. In conjunction with and based on our proposed determination that the South Coast area has attained and is currently attaining the 2006 24-hour PM2.5
                     NAAQS, in accordance with 40 CFR 51.1015, the EPA is proposing to issue a CDD for the South Coast PM2.5
                     nonattainment area for the 2006 24-hour PM2.5
                     NAAQS. Accordingly, the EPA is proposing to determine that the obligation to submit any remaining attainment-related SIP revisions arising from the EPA's September 16, 2020 finding that the area failed to attain the 2006 24-hour PM2.5
                     NAAQS by the Serious area attainment date is not applicable for so long as the area continues to attain those NAAQS. If the EPA finalizes this proposal, the requirements for this area to submit an attainment demonstration, RFP plan, quantitative milestones and quantitative milestone reports, contingency measures, and any other SIP revisions related to the attainment of the 2006 24-hour PM2.5
                     NAAQS will be suspended so long as this area continues to meet the standard. We note that as discussed in section I.B of this document, on December 29, 2020, California submitted a SIP revision to address these requirements. The EPA intends to evaluate and act on the remaining SIP elements in this submission through subsequent rulemakings, as appropriate. This CDD does not constitute a redesignation to attainment. The South Coast PM2.5
                     nonattainment area will remain designated nonattainment for the 2006 24-hour PM2.5
                     NAAQS until such time as the EPA determines, pursuant to sections 107 and 175A of the CAA, that the South Coast PM2.5
                     nonattainment area meets the CAA requirements for redesignation to attainment, including an approved maintenance plan showing that the area will continue to meet the standard for 10 years. We are also proposing to approve the South Coast PM2.5
                     Plan's 2018 base year emissions inventory as meeting the requirements of CAA section 172(c)(3) and 40 CFR 51.1008(c)(1). As authorized in section 110(k)(3) of the Act, the EPA is proposing to approve the submitted base year emissions inventory because we believe it fulfills all relevant requirements. The EPA is soliciting public comments on the issues discussed in this document. We will accept comments from the public on this proposal for the next 30 days. We will consider these comments before taking final action. VI. Statutory and Executive Order Reviews Additional information about these statutes and Executive Orders can be found at 
                    *https://www.epa.gov/​laws-regulations/​laws-and-executive-orders.* A. Executive Order 12866: Regulatory Planning and Review and Executive Order 13563: Improving Regulation and Regulatory Review This action is not a significant regulatory action and was therefore not submitted to the Office of Management and Budget (OMB) for review. This action proposes to issue a CDD for the South Coast PM2.5
                     nonattainment area and to approve a portion of a state submission as meeting federal requirements and imposes no new requirements. B. Paperwork Reduction Act (PRA) This action does not impose an information collection burden under the PRA. This action proposes to determine that the South Coast PM2.5
                     nonattainment area is attaining the 2006 24-hour PM2.5
                     NAAQS and to approve the base year emissions inventory in the South Coast PM2.5
                     Plan. Thus, this proposed action does not impose additional requirements beyond those imposed by state law.
                    ( print page 92881) C. Regulatory Flexibility Act (RFA) I certify that this action will not have a significant economic impact on a substantial number of small entities under the RFA. This action will not impose any requirements on small entities beyond those imposed by state law. The proposed CDD and approval of the base year emissions inventory does not create any new requirements and does not directly regulate any entities. D. Unfunded Mandates Reform Act (UMRA) This action does not contain any unfunded mandate as described in UMRA, 2 U.S.C. 1531-1538, and does not significantly or uniquely affect small governments. This action does not impose additional requirements beyond those imposed by state law. Accordingly, no additional costs to state, local, or tribal governments, or to the private sector, will result from this action. E. Executive Order 13132: Federalism This action does not have federalism implications. It will not have substantial direct effects on the states, on the relationship between the national government and the states, or on the distribution of power and responsibilities among the various levels of government. Pursuant to the CAA, this action proposes a CDD and to approve a base year emissions inventory. F. Executive Order 13175: Coordination With Indian Tribal Governments This action does not have tribal implications, as specified in Executive Order 13175, because the SIP is not approved to apply on any Indian reservation land or in any other area where the EPA or an Indian tribe has demonstrated that a tribe has jurisdiction, and it will not impose substantial direct costs on tribal governments or preempt tribal law. Thus, Executive Order 13175 does not apply to this action. G. Executive Order 13045: Protection of Children From Environmental Health Risks and Safety Risks The EPA interprets Executive Order 13045 as applying only to those regulatory actions that concern environmental health or safety risks that the EPA has reason to believe may disproportionately affect children, per the definition of “covered regulatory action” in section 2-202 of the Executive Order. Therefore, this action is not subject to Executive Order 13045 because it merely proposes a CDD and to approve a base year emissions inventory as meeting federal requirements. Furthermore, the EPA's Policy on Children's Health does not apply to this action. H. Executive Order 13211: Actions That Significantly Affect Energy Supply, Distribution, or Use This action is not subject to Executive Order 13211, because it is not a significant regulatory action under Executive Order 12866. I. National Technology Transfer and Advancement Act (NTTAA) Section 12(d) of the NTTAA directs the EPA to use voluntary consensus standards in its regulatory activities unless to do so would be inconsistent with applicable law or otherwise impractical. The EPA believes that this action is not subject to the requirements of section 12(d) of the NTTAA because application of those requirements would be inconsistent with the CAA. J. Executive Order 12898: Federal Actions To Address Environmental Justice in Minority Populations and Low-Income Populations Executive Order 12898 (Federal Actions To Address Environmental Justice in Minority Populations and Low-Income Populations, 59 FR 7629, February 16, 1994) directs Federal agencies to identify and address “disproportionately high and adverse human health or environmental effects” of their actions on communities with EJ concerns to the greatest extent practicable and permitted by law. Executive Order 14096 (Revitalizing Our Nation's Commitment to Environmental Justice for All, 88 FR 25251, April 26, 2023) builds on and supplements E.O. 12898 and defines EJ as, among other things, “the just treatment and meaningful involvement of all people, regardless of income, race, color, national origin, or Tribal affiliation, or disability in agency decision-making and other Federal activities that affect human health and the environment.” For the SIP portion of this action, under the CAA, the Administrator is required to approve a SIP submission that complies with the provisions of the Act and applicable federal regulations. 42 U.S.C. 7410(k); 40 CFR 52.02(a). Thus, in reviewing SIP submissions, the EPA's role is to review state choices and approve those choices if they meet the minimum criteria of the Act. Accordingly, this proposed CDD and approval of a base year emissions inventory does not impose any additional regulatory requirements on sources beyond those imposed by state law. The State did not evaluate EJ considerations as part of its attainment plan for the 2006 24-hour PM2.5
                     NAAQS; the CAA and applicable implementing regulations neither prohibit nor require such an evaluation. Consistent with the EPA's discretion under the CAA, the EPA has evaluated the EJ considerations of this action, as is described in the section of this document titled, “Environmental Justice Considerations.” The analysis was included in this document for the purpose of providing additional context and information about this rulemaking to the public, not as a basis of the proposed action. Due to the nature of the action being proposed here, this action is expected to have a neutral impact on the air quality of the affected area. In addition, there is no information in the record upon which this decision is based inconsistent with the stated goal of E.O. 12898/14096 of achieving EJ for communities with EJ concerns. List of Subjects in 40 CFR Part 52 Environmental protection
Air pollution control
Ammonia
Incorporation by reference
Intergovernmental relations
Nitrogen oxides
Particulate matter
Reporting and recordkeeping requirements
Sulfur oxides
Volatile organic compounds
 Dated: November 18, 2024. Martha Guzman Aceves, Regional Administrator, Region IX.


# Footnotes

1.
    
                         62 FR 38652. Back to Citation
 2.
    
                         40 CFR 50.7. Back to Citation
 3.
    
                         71 FR 61144 (October 17, 2006) and 40 CFR 50.13. Unless otherwise noted, all references to the PM2.5
                         NAAQS in this document are to the 2006 24-hour PM2.5
                         NAAQS of 35 μg/m3.
    
                        , codified at 40 CFR 50.13. Back to Citation
 4.
    
                         In December 2012, the EPA announced its decision to revise the level of the primary annual PM2.5
                         NAAQS to 12.0 μg/m3.
    
                         (78 FR 3086, January 15, 2013). On February 7, 2024, the EPA announced its decision to revise the level of the primary annual PM2.5
                         NAAQS once more to 9.0 μg/m3.
    
                         (89 FR 16202, March 6, 2024). Back to Citation
 5.
    
                         EPA, Air Quality Criteria for Particulate Matter, No. EPA/600/P-99/002aF and EPA/600/P-99/002bF, October 2004. Back to Citation
 6.
    
                         For example, see 72 FR 20586, 20589 (April 25, 2007). Back to Citation
 7.
    
                         74 FR 58688 (November 13, 2009). Back to Citation
 8.
    
                         79 FR 31566. Back to Citation
 9.
    
                         81 FR 1514. Back to Citation
 10.
    
                         Id. Back to Citation
 11.
    
                         Letter dated April 27, 2017, from Richard Corey, Executive Officer, CARB, to Alexis Strauss, Acting Regional Administrator, EPA Region IX. Back to Citation
 12.
    
                         84 FR 3305. Back to Citation
 13.
    
                         85 FR 57733 (September 16, 2020). Back to Citation
 14.
    
                         Id. at 57735. Back to Citation
 15.
    
                         Letter dated December 28, 2020, from Richard W. Corey, Executive Officer, CARB, to John W. Busterud, Regional Administrator, EPA Region 9, with enclosures (submitted electronically December 29, 2020). 16.
    
                         CARB Executive Order S-20-33, “South Coast PM2.5
                         SIP Revision Submittal.” Back to Citation
 17.
    
                         Id. Back to Citation
 18.
    
                         CAA section 189(d), 40 CFR 51.1004(a)(3), and 40 CFR 51.1010(c). Back to Citation
 19.
    
                         81 FR 58010, 58098 (August 24, 2016). Back to Citation
 20.
    
                         40 CFR 51.1003(c)(1). Back to Citation
 21.
    
                         81 FR 58010. Back to Citation
 22.
    
                         In the context of CDDs, the EPA distinguishes between attainment planning requirements of the CAA, which relate to the attainment demonstration for an area and related control measures designed to bring an area into attainment for the given NAAQS as expeditiously as practicable, and other types of requirements, such as permitting requirements under the nonattainment new source review program, emissions inventory requirement, and specific control requirements independent of those strictly needed to ensure timely attainment of the given NAAQS. 81 FR 58010, 58128. Back to Citation
 23.
    
                         Id. Back to Citation
 24.
    
                         Id. On October 22, 2021, the EPA approved SCAQMD's Rule 1325, “Federal PM2.5
                         New Source Review Program” as meeting applicable CAA requirements for new source review, thereby satisfying the requirement for new source review (86 FR 58592). This action includes our proposed approval of the base year emissions inventory included in the attainment plan for the South Coast nonattainment area submitted on December 29, 2020. See Section III of this document. Back to Citation
 25.
    
                         See 40 CFR 50.7; 40 CFR part 50, appendix L; 40 CFR part 53; 40 CFR part 58, and 40 CFR part 58, appendices A, C, D, and E. Back to Citation
 26.
    
                         40 CFR part 58, appendix D, section 4.7.2. Back to Citation
 27.
    
                         40 CFR 58.10(a)(1). Back to Citation
 28.
    
                         We have included copies of SCAQMD's annual network plans for 2021-2023 in the docket for this rulemaking. Back to Citation
 29.
    
                         We have included copies of the Pechanga Band's annual network plans for 2021-2023 in the docket for this rulemaking. Back to Citation
 30.
    
                         There are a number of other PM2.5
                         monitoring sites within the South Coast Air Basin, including other sites operated by the District, the National Park Service, and certain Indian tribes, but the data collected from these sites are non-regulatory and not eligible for comparison with the PM2.5
                         NAAQS. Back to Citation
 31.
    
                         We have included SCAQMD's annual data certifications for 2021, 2022, and 2023 in the docket for this rulemaking. Back to Citation
 32.
    
                         We have included the Pechanga Band's annual data certifications for 2021 and 2022 in the docket for this rulemaking. Back to Citation
 33.
    
                         Letter dated April 15, 2022, from Gwen Yoshimura, Manager, Air Quality Analysis Office, Air and Radiation Division, U.S. EPA Region IX, to Rene Bermudez, Atmospheric Measurements Manager, SCAQMD. 34.
    
                         Letter dated May 26, 2022, from Gwen Yoshimura, Manager, Air Quality Analysis Office, Air and Radiation Division, U.S. EPA Region IX, to Rene Bermudez, Atmospheric Measurements Manager, SCAQMD. Back to Citation
 35.
    
                         See 40 CFR part 50, appendix N, section 4.2(b). Back to Citation
 36.
    
                         Letter dated March 17, 2021, from Elizabeth Adams, Director, Air and Radiation Division, EPA Region IX, to Dr. Matt Miyasato, Executive Officer, SCAQMD, with enclosure titled, “Technical Systems Audit Report, SCAQMD, June 1-June 5, 2020.” Back to Citation
 37.
    
                         Letter dated August 22, 2022, from Elizabeth Adams, Director, Air and Radiation Division, EPA Region IX, to Kelsey Stricker, Environmental Director, Pechanga Band of Luiseno Indians, with enclosure titled, “Technical Systems Audit Report of the Ambient Air Monitoring Program, Pechanga Band of Luiseno Indians, September 27-30 and October 7, 2022.” Back to Citation
 38.
    
                         EPA, AQS Design Value Report (AMP480), Report Request ID: 2228533, October 1, 2024. Back to Citation
 39.
    
                         40 CFR 51.1015(b). Back to Citation
 40.
    
                         81 FR 58010, 58098-58099. Back to Citation
 41.
    
                         EPA, “Emissions Inventory Guidance for Implementation of Ozone and Particulate Matter National Ambient Air Quality Standards (NAAQS) and Regional Haze Regulations,” May 2017 (“Emissions Inventory Guidance”), available at 
                        *https://www.epa.gov/​air-emissions-inventories/​air-emissions-inventory-guidance-implementation-ozone-and-particulate.* Back to Citation
 42.
    
                         The Emissions Inventory Guidance identifies the types of sources for which the EPA expects states to provide condensable PM emissions inventories. Emissions Inventory Guidance, Section 4.2.1 (“Condensable PM Emissions”), pp. 63-65. Back to Citation
 43.
    
                         40 CFR 51.1008. Back to Citation
 44.
    
                         40 CFR 51.1008(c)(1). Back to Citation
 45.
    
                         84 FR 41717 (August 15, 2019). EMFAC is short for 
                        *EM*
                        ission 
                        *FAC*
                        tor. 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. 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**
                        . On November 15, 2022, the EPA approved and announced the availability of EMFAC2021, the latest update to the EMFAC model for use by State and local governments to meet CAA requirements (87 FR 68483). Back to Citation
 46.
    
                         AP-42 has been published since 1972 as the primary source of the EPA's emissions factor information and is available at 
                        *https://www.epa.gov/​air-emissions-factors-and-quantification/​ap-42-compilation-air-emissions-factors.*
                         It contains emissions factors and process information for more than 200 air pollution source categories. A source category is a specific industry sector or group of similar emitting sources. The emissions factors have been developed and compiled from source test data, material balance studies, and engineering estimates. The EPA released an update to AP-42 in January 2011 that revised the equation for estimating paved road dust emissions based on an updated data regression that included new emissions tests results. 76 FR 6328 (February 4, 2011). CARB used the revised 2011 AP-42 methodology in developing on-road mobile source emissions; see 
                        *https://ww3.arb.ca.gov/​ei/​areasrc/​fullpdf/​2021_​paved_​roads_​summary_​7_​9.pdf,*
                         p.2. Back to Citation
 47.
    
                         “Transcript of Proceedings, October 07, 2020, Regional Public Hearing for the Proposed Attainment Plan for the 2006 24-Hour PM2.5
                         Standard for the South Coast Air Basin,” and South Coast Air Quality Management District Governing Board Resolution 20-21, dated December 4, 2020. Back to Citation
 48.
    
                         Information about the SCAQMD's Annual Emissions Reporting program is available at 
                        *http://www.aqmd.gov/​home/​rules-compliance/​compliance/​annual-emission-reporting.* Back to Citation
 49.
    
                         SCAG, “The 2016-2040 Regional Transportation Plan/Sustainable Communities Strategy: A Plan for Mobility, Accessibility, Sustainability and a High Quality of Life.” Available at 
                        *https://scag.ca.gov/​2016-rtpscs.* Back to Citation
 50.
    
                         
                        *https://github.com/​mmb-carb/​ESTA.* Back to Citation
 51.
    
                         South Coast PM2.5
                         Plan, p. 3-4. Back to Citation
 52.
    
                         Id. at appendix I, tables C1 through C4. Back to Citation
 53.
    
                         EJSCREEN provides a nationally consistent dataset and approach for combining environmental burden and socioeconomic indicators. EJSCREEN is available at 
                        *https://www.epa.gov/​ejscreen/​what-ejscreen.*
                         The EPA used EJSCREEN to obtain environmental burden and socioeconomic indicators representing the South Coast PM2.5
                         nonattainment area. These indicators are included in EJSCREEN reports that are available in the rulemaking docket for this action. 54.
    
                         EPA Region IX, “EJSCREEN (version 2.3) Analysis for the Four Counties of the South Coast Nonattainment Area,” September 2024. Back to Citation
 55.
    
                         EJSCREEN reports environmental burden indicators (
                        *e.g.,*
                         toxic releases to air, lead paint exposure, and traffic proximity and volume) and socioeconomic indicators (
                        *e.g.,*
                         people of color, low income, and limited English-speaking household). The value of a particular indicator measures how the community of interest compares with the state or national average. For example, if a given location is at the 95th percentile nationwide, this means that only five percent of the US population has a higher value than the average person in the location being analyzed. EJSCREEN also reports EJ indexes, which are combinations of a single environmental burden indicator with the EJSCREEN Demographic Index. For additional information about environmental burden indicators, demographic indexes, and EJ indexes reported by EJSCREEN, see EPA, “EJScreen Environmental Justice Mapping and Screening Tool, EJScreen Technical Documentation for Version 2.3,” July 2024, Section 3. Back to Citation
 56.
    
                         EPA, “Technical Guidance for Assessing Environmental Justice in Regulatory Analysis,” June 2016, Section 4.1. Back to Citation
 57.
    
                         Id. Back to Citation
 58.
    
                         81 FR 58010, 58128. Back to Citation
 59.
    
                         Id. Back to Citation
 60.
    
                         CARB, “South Coast Air Basin Attainment Plan for the 2012 Annual PM2.5
                         Standard, Resolution 24-7,” June 27, 2024. Back to Citation
 61.
    
                         
                        *https://www.epa.gov/​newsreleases/​biden-harris-administration-announces-nearly-500-million-effort-cut-transportation-and.* Back to Citation
 62.
    
                         
                        *https://www.epa.gov/​newsreleases/​biden-harris-administration-announces-selections-nearly-3-billion-investments-clean.* Back to Citation


[FR Doc. 2024-27517 Filed 11-22-24; 8:45 am] BILLING CODE 6560-50-P