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 Environmental Protection Agency 40 CFR Parts 52 and 81
[EPA-R10-OAR-2022-0124; FRL-9488-01-R10]
 AGENCY: Environmental Protection Agency (EPA).
 ACTION: Proposed rule.
 SUMMARY: The Environmental Protection Agency (EPA) proposes to redesignate the Oakridge, Oregon nonattainment area (Oakridge NAA or Oakridge area) to attainment for the 2006 24-hour fine particulate matter (PM2.5) National Ambient Air Quality Standard (NAAQS). EPA also proposes to approve a maintenance plan for the area demonstrating continued compliance with the PM2.5
                         NAAQS through 2035, which the Lane Regional Air Protection Agency (LRAPA) developed in coordination with the Oregon Department of Environmental Quality (ODEQ), for inclusion into the Oregon State Implementation Plan (SIP). The Oakridge PM2.5
                         maintenance plan was submitted to EPA by ODEQ along with the redesignation request on January 13, 2022. Additionally, EPA proposes to approve the motor vehicle emissions budgets included in the Oakridge PM2.5
                         maintenance plan and inform the public that we are starting the adequacy process for the proposed motor vehicle emissions budgets, including a public comment period. EPA also proposes to approve additional control measures because incorporation of these measures will strengthen the Oregon SIP and ensure PM2.5
                         emissions reductions in the Oakridge area. Finally, EPA proposes to take final agency action on an exceptional events request submitted by ODEQ on July 22, 2021 and concurred on by EPA on April 1, 2022. EPA proposes these actions pursuant to the Clean Air Act (CAA or the Act).
 DATES: Comments must be received on or before June 6, 2022.
 ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R10-OAR-2022-0124, at 
                        *https://www.regulations.gov.*
                         Follow the online instructions for submitting comments. Once submitted, comments cannot be edited or removed from 
                        *Regulations.gov*. EPA may publish any comment received to its public docket. Do not electronically submit any information you consider to be Confidential Business Information (CBI) or other information the disclosure of which is restricted by statute. Multimedia submissions (audio, video, etc.) must be accompanied by a written comment. The written comment is considered the official comment and should include discussion of all points you wish to make. EPA will generally not consider comments or comment contents located outside of the primary submission (
                        *i.e.*
                         on the web, cloud, or other file sharing system). For additional submission methods, the full EPA public comment policy, information about CBI or multimedia submissions, and general guidance on making effective comments, please visit 
                        *https://www.epa.gov/​dockets/​commenting-epa-dockets.*
 FOR FURTHER INFORMATION CONTACT: Christi Duboiski (15-H13), EPA Region 10, 1200 Sixth Avenue (Suite 155), Seattle WA 98101, at (360) 753-9081, or 
                        *duboiski.christi@epa.gov*.


SUPPLEMENTARY INFORMATION: Throughout this document whenever “we,” or “our” is used, it refers to EPA. Table of Contents I. Background II. Clean Air Act Requirements for Redesignation to Attainment III. EPA's Analysis of Oregon's Submittal A. Attainment Determination B. Applicable Requirements Under Section 110 and Part D of the CAA 1. CAA Section 110 General SIP Requirements 2. Part D of Title I Requirements 3. Fully Approved SIP Under CAA Section 110(k) C. Improvement in Air Quality Due to Permanent and Enforceable Measures D. Fully Approved Maintenance Plan 1. Attainment Inventory 2. Maintenance Demonstration 3. Monitoring Network and Verification of Continued Attainment 4. Contingency Plan E. Transportation Conformity and Motor Vehicle Emissions Budgets F. State Rule Changes To Reflect the Redesignation IV. Proposed Action V. Incorporation by Reference VI. Statutory and Executive Orders Review I. Background On October 17, 2006, EPA revised the level of the 24-hour PM2.5
                     NAAQS, lowering the primary and secondary standards from the 1997 standard of 65 micrograms per cubic meter (μg/m3
                    ) to 35 μg/m3
                     (71 FR 61143). On November 13, 2009, EPA designated a portion of Lane County, Oregon nonattainment for the 2006 24-hour PM2.5
                     NAAQS (74 FR 58688). This nonattainment area is referred to as the Oakridge, Oregon PM2.5
                     NAA (Oakridge NAA or Oakridge area). The Oakridge NAA boundary is a rectangular area that includes the City of Oakridge and the small town of Westfir. The City of Oakridge is situated in a valley where the middle fork of the Willamette River flows east to west, and mountains rise on the north and south sides. Westfir is a very small isolated rural mountain community also located in a valley along the north fork of the Willamette River about 1-mile NW of Oakridge. It is surrounded by the same high mountains. This topography can act as a barrier to air movement in the Oakridge NAA during temperature inversions, which occur in the winter months and are often the cause of elevated concentrations of PM2.5
                    . Additional information pertaining to the specific boundary for the Oakridge NAA can be found in the November 13, 2009, final designations action for the 2006 24-hour PM2.5
                     NAAQS (74 FR 58688). The nonattainment designation of the Oakridge NAA required Oregon to prepare and submit an attainment plan to meet statutory and regulatory requirements.[1]
                    
                     ODEQ submitted this attainment plan to EPA on December 12, 2012 (2012 attainment plan). EPA approved the description of the Oakridge NAA and the baseline emissions inventory and disapproved everything else submitted in the attainment plan on October 21, 2016 (81 FR 72714). ODEQ submitted a supplement to the attainment plan on January 20, 2017 (2017 Oakridge Update). On February 8, 2018, EPA approved the 2017 Oakridge Update including the attainment year emission inventory, the control measures in the attainment plan as meeting reasonably available control measures/technology (RACM/RACT), the attainment demonstration, the motor vehicle emissions budgets (MVEBs) for PM2.5, the demonstration of reasonable progress, the quantitative milestones and contingency measures (83 FR 5537). In addition, on July 18, 2016, EPA granted a one-year extension, under CAA section 188(d), to the December 31, 2015, Moderate attainment date for the 2006 24-hour PM2.5
                     Oakridge NAA (81 FR 46612). On February 8, 2018, EPA finalized a determination that the Oakridge NAA had attained the 2006 24-hour PM2.5
                     NAAQS (Determination of Attainment) by the December 31, 2016, attainment date (83 FR 5537). II. Clean Air Act Requirements for Redesignation to Attainment The CAA provides the requirements for redesignating a nonattainment area to attainment. Specifically, section 107(d)(3)(E) of the CAA, allows for redesignation provided that: (1) EPA determines that the area has attained the applicable NAAQS; (2) EPA has fully approved the applicable implementation plan for the area under section 110(k) of the CAA; (3) EPA determines that the improvement in air quality is due to permanent and enforceable reductions in emissions resulting from implementation of the applicable SIP and applicable Federal air pollutant control regulations and other permanent and enforceable reductions; (4) EPA has fully approved a maintenance plan for the area as meeting the requirements of section 175A of the CAA; and (5) the state has met all requirements applicable to the area under section 110 and part D of the CAA. In this proposed action, EPA will review CAA section 107(d)(3)(E) requirements (2) and (5) together as part of our evaluation of Oregon's redesignation request. EPA has provided guidance on redesignations in the “General Preamble,” [2]
                    
                     and has provided further guidance on processing redesignation requests in the following documents: (1) “Procedures for Processing Requests to Redesignate Areas to Attainment,” Memorandum from John Calcagni, Director, Air Quality Management Division, September 4, 1992 (hereafter the “Calcagni Memo”); (2) “State Implementation Plan (SIP) Actions Submitted in Response to Clean Air Act (CAA) Deadlines,” Memorandum from John Calcagni, Director, Air Quality Management Division, October 28, 1992; and (3) “Part D New Source Review (part D NSR) Requirements for Areas Requesting Redesignation to Attainment,” Memorandum from Mary D. Nichols, Assistant Administrator for Air and Radiation, October 14, 1994. These documents are included in the Docket for this proposed action. III. EPA's Analysis of Oregon's Submittal EPA proposes to redesignate the Oakridge NAA to attainment for the 2006 24-hour PM2.5
                     NAAQS and proposes to approve into the Oregon SIP the associated Oakridge PM2.5
                     maintenance plan. EPA's proposed approval of the redesignation request and maintenance plan is based upon EPA's determination that the area continues to attain the 2006 24-hour PM2.5
                     NAAQS and that all other redesignation criteria have been met for the area. Sections III.A through D of this document describe how Oregon's January 13, 2022, submittal satisfies the requirements of section 107(d)(3)(E) of the CAA for the 2006 24-hour PM2.5
                     standard.[3] Oregon's submittal also addresses transportation MVEBs and emissions from wildfire-influenced PM2.5
                     concentrations recorded in the Oakridge NAA in 2020. EPA proposes to approve the MVEBs and proposes to approve the exclusion of ambient air quality monitoring data associated with the wildfire-influenced exceptional events that affected this data in September of 2020 for the purposes of showing continued attainment of the NAAQS.
                    ( print page 26712) A. Attainment Determination To redesignate an area from nonattainment to attainment, the CAA requires EPA to determine that the area has attained the applicable NAAQS (CAA section 107(d)(3)(E)(i)). EPA determines whether an area has attained the 2006 24-hour PM2.5
                     NAAQS based upon measured air quality levels at each eligible monitoring site to produce a design value equal to or below 35 μg/m[3]
                    .[4]
                    
                     A state must demonstrate that an area has attained the 2006 24-hour PM2.5
                     NAAQS through submittal of ambient air quality data from an ambient air monitoring network representing expected maximum PM2.5
                     concentrations. The data must be quality-assured, quality-controlled and certified in EPA's Air Quality System (AQS) and it must show that the three-year average of valid PM2.5
                     98th percentile mass concentrations is equal to or below the 2006 24-hour PM2.5
                     NAAQS (35 μg/m3
                    ), pursuant to 40 CFR 50.13. In making this showing, three years of complete air quality data must be used. The Exceptional Event Rule Congress has recognized that it may not be appropriate for EPA to use certain monitoring data collected by the ambient air quality monitoring network and maintained in EPA's AQS database [5]
                    
                     in certain regulatory determinations. Thus, in 2005, Congress provided the statutory authority for the exclusion of data influenced by “exceptional events” meeting specific criteria by adding section 319(b) to the CAA.[6]
                    
                     To implement this 2005 CAA amendment, EPA promulgated the 2007 Exceptional Events Rule.[7]
                    
                     The 2007 Exceptional Events Rule created a regulatory process codified at 40 CFR parts 50 and 51 (sections 50.1, 50.14 and 51.930). These regulatory sections, which superseded EPA's previous guidance on handling data influenced by events, contain definitions, procedural requirements, requirements for air agency demonstrations, criteria for EPA's approval of the exclusion of event-affected air quality data from the data set used for regulatory decisions, and requirements for air agencies to take appropriate and reasonable actions to protect public health from exceedances or violations of the NAAQS. In 2016, EPA promulgated a comprehensive revision to the 2007 Exceptional Events Rule.[8]
                    
                     The 2016 Exceptions Events Rule revision included the requirement that, if a state demonstrates that emissions from a wildfire smoke event caused a specific air pollution concentration in excess of the NAAQS at a particular air quality monitoring location and otherwise satisfies the requirements of 40 CFR 50.14, EPA must exclude that data from use in determinations of exceedances and violations.[9] The Oakridge NAA Exceptional Event Demonstrations and Concurrences The CAA allows for the exclusion of air quality monitoring data from design value calculations when there are NAAQS exceedances caused by events, such as wildfires, that meet the criteria for an exceptional event identified in EPA's Exceptional Events Rule at 40 CFR 50.1, 50.14 and 51.930. For the purposes of this proposed action, on July 22, 2021, ODEQ submitted an exceptional events demonstration to show that PM2.5
                     concentrations recorded at the Oakridge Willamette Center monitor from September 11, 2020 through September 16, 2020 were influenced by wildfires. EPA concurred on this request on April 1, 2022. EPA found that Oregon's demonstration met the Exceptional Events Rule criteria and determined that these wildfire events had regulatory significance for purposes of calculating the area's most recent design value to demonstrate the area continues to attain the standard in order to redesignate the area to attainment for the PM2.5
                     NAAQS. As such, EPA proposes to take final regulatory action on the concurred dates, as detailed in the docket, as exceptional events to be removed from the data set used for regulatory purposes. For this proposed action, EPA will rely on the calculated values that exclude the event-influenced data for the purpose of demonstrating continued attainment of the 2006 PM2.5
                     NAAQS. Further details on Oregon's analyses and EPA's concurrences can be found in the docket for this regulatory action. While EPA may agree with Oregon's request to exclude event-influenced air quality monitoring data from regulatory decisions, these regulatory actions require EPA to provide an opportunity for public comment on the claimed exceptional events and all supporting data prior to EPA taking final agency action. This proposed action provides the public with an opportunity to comment on the claimed exceptional events, all supporting documents and EPA's proposed concurrence with Oregon's request. Evaluation of Continued Attainment As previously noted, on February 8, 2018, EPA finalized a Determination of Attainment for the Oakridge NAA based upon quality-assured and certified ambient air quality monitoring data for the 2014-2016 design value period (83 FR 5537). The monitoring data used as the basis for the Determination of Attainment under CAA section 188(b)(2) is provided in Table 1 of this document. Table 1—Oakridge Area PM
                        2.5
                         2016 Attaining Design Value
Monitor
AQS site ID
98th percentile value (μg/m3
                            )
2014-2016
                             design value2014
2015
2016Willamette Center
410392013
41.1
28.9
21.7
31
 For this proposed action, EPA reviewed the subsequent PM2.5
                     ambient air monitoring data in the Oakridge area for the monitoring design value periods of 2017-2020. Consistent with the requirements at 40 CFR part 50, this ambient monitoring data in EPA's AQS has been quality-assured, quality-controlled and certified by ODEQ. As Table 2 indicates, the Oakridge NAA has continued to attain the 2006 24-hour PM2.5
                     NAAQS since EPA issued its 
                    ( print page 26713)
                    February 8, 2018, Determination of Attainment for the area based on the 2016 attaining design value shown in Table 1 of this document. Table 2—Oakridge Area PM
                        2.5
                         Design Values (2017-2020)
Monitor
98th percentile values (μg/m3
                            )
2017-2020 design valuesa
                             (μg/m3
                            )2015
2016
2017
2018
2019
2020
2017
2018
2019
2020Willamette Center
28.9
21.7
35.7
33.2
36.7
32.2
29
30
35
34a
                         EPA concurred on the removal of exceptional events data for 2017 in a letter dated 5/21/2020 and exceptional events data for 2020 in a letter dated 4/01/2022. The specified data was excluded from AQS.
 EPA's review of the monitoring data supports the previous determination that the area has attained the standard and therefore EPA finds it is appropriate to conclude the area has continued to attain the NAAQS through 2020, based on uninterrupted attaining design values at the Willamette Center monitor. B. Applicable Requirements Under Section 110 and Part D of the CAA Section 107(d)(3)(E)(ii) and (v) of the CAA states that for an area to be redesignated to attainment, it must be determined that the Administrator has fully approved the applicable implementation plan for the area under CAA section 110(k) and all the requirements applicable to the Area under section 110 of the CAA (general SIP requirements) and part D of Title I of the CAA (SIP requirements for nonattainment areas) must be met. We interpret this to mean that, for a redesignation request to be approved, the state must have met all requirements that applied to the subject area prior to, or at the time of, submitting a complete redesignation request. EPA may rely on prior SIP approvals in approving a redesignation request [10]
                    
                     as well as any additional measure it may approve in conjunction with a redesignation action. 1. CAA Section 110 General SIP Requirements Section 110(a)(2) of Title I of the CAA delineates the general requirements for a SIP, which include enforceable emissions limitations and other control measures, means or techniques, provisions for the establishment and operation of appropriate devices necessary to collect data on ambient air quality, and programs to enforce the limitations. The general SIP elements and requirements set forth in CAA section 110(a)(2) include, but are not limited to the following: Submittal of a SIP that has been adopted by the state after reasonable public notice and hearing;
                Provisions for establishment and operation of appropriate procedures needed to monitor ambient air quality;
                Implementation of a source permit program; provisions for the implementation of part C requirements (PSD);
                Provisions for the implementation of part D requirements for NSR permit programs;
                Provisions for air pollution modeling; and
                Provisions for public and local agency participation in planning and emission control rule development.[11] We note that SIPs must be fully approved only with respect to applicable requirements for purposes of redesignation in accordance with section 107(d)(3)(E)(ii). Similarly, EPA believes that the other CAA section 110(a)(2) (and part D) requirements that are not connected with nonattainment plan submittals and not linked with an area's attainment status are not applicable requirements for purposes of redesignation because the area will still be subject to these requirements after it is redesignated. EPA considers the CAA section 110(a)(2) (and part D) requirements that relate to a particular nonattainment area's designation and classification as the relevant measures to evaluate in reviewing a redesignation request. This approach is consistent with EPA's existing policy on applicability of the conformity SIP requirement for redesignations.[12] EPA has reviewed the Oregon SIP and concludes that it meets the general SIP requirements under Section 110(a)(2) of the CAA to the extent they are applicable for the purposes of redesignation.[13]
                    
                     EPA has previously approved provisions of Oregon's SIP as demonstrating compliance with the CAA section 110(a)(2) requirements for the 2006 PM2.5
                     NAAQS (78 FR 46514, August 1, 2013, and 80 FR 2313, January 15, 2015). These requirements are, however, statewide requirements that are not linked to the PM2.5
                     nonattainment status of the Oakridge NAA. In addition, there are no outstanding or disapproved applicable SIP submittals with respect to the Oakridge portion of the SIP that would prevent redesignation of the Oakridge NAA for the PM2.5
                     NAAQS. Therefore, we conclude that ODEQ and LRAPA have met all general SIP requirements for the Oakridge NAA that are applicable for purposes of redesignating the area to attainment of the PM2.5. 2. Part D of Title I Requirements Part D of Title I of the CAA sets forth the basic nonattainment plan requirements applicable to all nonattainment areas at subpart 1 (CAA sections 172-176) and requirements specific to PM10
                     and PM2.5
                     areas at subpart 4 (CAA section 189). On August 24, 2016, EPA promulgated the Fine Particulate Matter National Ambient Air Quality Standards; State Implementation Plan Requirements rule.[14]
                    
                     This rule implements the requirements of part D of Title I of the CAA for areas designated nonattainment for any PM2.5
                     NAAQS. In accordance with 40 CFR 51.1015, upon a determination by EPA that a Moderate PM2.5
                     nonattainment area has attained the PM2.5
                     NAAQS, the requirements for the state to submit an attainment demonstration, provisions demonstrating that RACM (including RACT for stationary sources) shall be implemented no later than 4 years following the date of designation of the area, Reasonable Further Progress (RFP) plan, quantitative milestones (QM) and reports, and contingency measures for the area shall be suspended until such time as: (1) The area is redesignated to attainment, after which such requirements are permanently discharged; or, (2) EPA determines that the area has re-violated the PM2.5
                     NAAQS. Those states containing Moderate PM2.5
                     NAAs were required to submit a 
                    ( print page 26714)
                    SIP by December 31, 2014, which demonstrated attainment of the PM2.5
                     NAAQS by December 31, 2015.[15]
                    
                     Pursuant to CAA section 188(d) and 40 CFR 51.1005(a), on July 18, 2016, EPA extended the attainment date for the Oakridge NAA from December 31, 2015 to December 31, 2016 (81 FR 46612). As stated in the “Background” section of this document, EPA has approved all attainment plan elements for the Oakridge NAA. Specifically, EPA approved the following elements of the Oakridge attainment plan: Base year emissions inventory (October 21, 2016, 81 FR 72714); control measures, RACM/RACT level emission controls, attainment demonstration, contingency measures, RFP plan, QM and MVEB (February 8, 2018, 83 FR 5537); and nonattainment NSR (October 5, 2018, 83 FR 50274). In addition, Pursuant to 40 CFR 51.1015(a), on February 8, 2018, EPA determined that the Oakridge NAA achieved a Clean Data Determination (CDD) in accordance with EPA's clean data policy and that the Oakridge area attained the 2006 24-hour PM2.5
                     NAAQS by the December 31, 2016, attainment date (83 FR 5537). Determinations of attainment do not relieve states from submitting and EPA from approving certain part D planning requirements for the 2006 PM2.5
                     NAAQS. CAA section 172(c)(3) requires submittals and approval of a comprehensive, accurate and current inventory of actual emissions. For purposes of the PM2.5
                     NAAQS, this emissions inventory should address not only direct emissions of PM2.5, but also emissions of all precursors to PM2.5
                     formation, 
                    *i.e.,*
                     SO2, NOX, VOC, and ammonia. As previously discussed, EPA determined that Oregon met the CAA section 172(c)(3) comprehensive emissions inventory requirement in a final rulemaking on October 21, 2016 (81 FR 72714). CAA section 172(c)(4) requires the identification and quantification of allowable emissions for major new or modified stationary sources in an area, and CAA section 172(c)(5) requires source permits for the construction and operation of new or modified major stationary sources anywhere in the nonattainment area. EPA first approved the requirements of the part D, subpart 1 NSR permit program for LRAPA on December 27, 2011 (76 FR 80747, 80748). Subsequently, LRAPA revised its rules to meet additional part D, subpart 4 NSR requirements promulgated by EPA (81 FR 58010, August 24, 2016) and to align with the ODEQ's rules.[16]
                    
                     EPA approved LRAPA's rules on October 5, 2018 (83 FR 50274). Once the Oakridge NAA is redesignated to attainment, the prevention of significant deterioration (PSD) requirements of part C of the CAA will apply. LRAPA's PSD regulations are codified in LRAPA's rules at Title 38 (New Source Review) in conjunction with other provisions including but not limited to LRAPA's rules in Titles 12, 31, 34, 35, 40, 42, and 50. We most recently approved revisions to LRAPA's PSD program on October 5, 2018 (83 FR 50274). EPA finds that LRAPA's PSD provisions meet all applicable Federal requirements for any area designated unclassifiable or attainment, and these provisions will become fully effective in the Oakridge NAA upon redesignation of the area to attainment. CAA section 172(c)(7) requires the SIP to meet the applicable provisions of CAA section 110(a)(2). As noted above, we find that the Oregon SIP meets the CAA section 110(a)(2) applicable requirements. For purposes of redesignation to attainment for the 2006 24-hour PM2.5
                     NAAQS, EPA proposes to find that LRAPA has met all the applicable SIP requirements under part D of Title I of the CAA in accordance with section 107(d)(3)(E)(v) of the CAA. 3. Fully Approved SIP Under CAA Section 110(k) Section 110(k) of the CAA sets out provisions governing EPA's review of SIP submittals. In order for an area to qualify for redesignation, the SIP for the area must be fully approved under section 110(k) of the CAA. As discussed in Sections III.B.1 and III.B.2 of this document, for purposes of redesignation to attainment for the 2006 24-hour PM2.5
                     NAAQS, EPA has fully approved all applicable requirements of Oregon's SIP for the Oakridge area in accordance with CAA section 110(k). Therefore, the criterion for redesignation, set forth at CAA section 107(d)(3)(E)(ii), is satisfied. C. Improvement in Air Quality Due to Permanent and Enforceable Measures Section 107(d)(3)(E)(iii) of the CAA provides that for an area to be redesignated to attainment, the Administrator must determine that the improvement in air quality is due to permanent and enforceable reductions in emissions resulting from implementation of the applicable implementation plan, implementation of applicable Federal air pollutant control regulations, and other permanent and enforceable reductions. The main source of PM2.5
                     emissions in the Oakridge NAA during the winter season days—when concentrations of emissions accumulate leading to exceedances of the 2006 24-hour PM2.5
                     NAAQS—is wood combustion in woodstoves, fireplaces and pellet stoves. Therefore, LRAPA identified strategies in the 2017 Oakridge Update that focused primarily on residential wood combustion (RWC) emission reductions such as Oakridge's mandatory curtailment program and the woodstove change-out programs. EPA approved these control measures as RACM into the Oregon SIP on February 8, 2018 (83 FR 5537), making them federally enforceable. The 2017 Oakridge Update includes specific sections of the City of Oakridge's RWC Ordinance 920 (RWC Ordinance) as it applies within the City of Oakridge. The SIP-approved provisions of the RWC Ordinance include a mandatory curtailment program, which has been important in helping this area reach attainment of the NAAQS. Modeling showed that the curtailment program would result in a calculated PM2.5
                     emissions reduction of 7.1 μg/m3
                     in the Oakridge NAA, the largest of all the control measures included in the plan. The provisions of the RWC Ordinance that EPA approved into the SIP also prohibit the burning of any fuel other than “seasoned wood,” which is defined as any species of wood that has been sufficiently dried to contain 20 percent or less moisture by weight. EPA also approved into the SIP provisions of the RWC Ordinance that specifically prohibit the burning of specified materials such as plastic, rubber products, petroleum-treated materials and other materials which normally emit dense smoke, noxious odors, or hazardous air contaminants in a solid fuel burning device. LRAPA also quantified the emission reduction benefits from woodstove change-outs that were conducted between 2009 and 2012, replacing 90 uncertified woodstoves in the Oakridge NAA. These woodstove change-out programs achieved permanent and enforceable emissions reductions because the higher-emitting woodstoves were removed and required to be destroyed. In addition, the Oregon Heat Smart Program, a statewide mandate approved by EPA on October 11, 2017 
                    ( print page 26715)
                    (82 FR 47122), and the RWC Ordinance prohibit the installation of non-EPA certified devices and ban the sale or installation of non-EPA certified devices in new or existing buildings. The collective permanent and enforceable PM2.5
                     reductions for these changeout programs in the Oakridge NAA were calculated to be 2.6 μg/m3
                    . LRAPA also referenced Federal transportation and fuel-related control measures to reduce mobile source emissions, including the “Tier 3 Motor Vehicle Emission and Fuel Standards Rule” as permanent and enforceable reductions leading to improvement in air quality (1.3 μg/m3
                     reduction on a worst-case winter day) and ultimately to attainment, in the Oakridge NAA. 
                    *See*79 FR 23414 (April 28, 2014). The RWC Ordinance 920—Section Two(3) was initially submitted in the 2017 Oakridge Update, but was ultimately not approved as part of the 2017 Oakridge Update. The RWC Ordinance 920—Section Two(3) was later resubmitted as part of the Oakridge PM2.5
                     maintenance plan. The Lane County Code—
                    *Restriction on Use of Solid Fuel Space Heating Devices*
                     (9.120-9.140) (Lane County Code) is also included in the Oakridge PM2.5
                     maintenance plan submittal and applies more broadly to the Oakridge Urban Growth Boundary. Both establish additional permanent and enforceable control measures on residential heating devices for the purpose of ensuring continued attainment in the Oakridge NAA. The Lane County Code, like the previously approved provisions of the RWC Ordinance, includes a curtailment program in the Oakridge urban growth boundary, prohibiting the burning of any fuel other than seasoned wood and other specified prohibited materials in solid-fuel heating devices. These restrictions on materials that may be burned limit PM2.5
                     emissions from woodstoves and fireplaces on a continuous basis. Section Two(3) of the RWC Ordinance, which EPA did not act on as part of the 2017 Oakridge Update, prohibits emissions from solid-fuel heating devices with an opacity greater than 20%. The Lane County Code, included in the Oakridge PM2.5
                     maintenance plan submittal, also includes this restriction. These 20% opacity limits provide a visual indicator for the proper operation of a solid-fuel heating device, including the use of properly seasoned wood. The opacity limits apply at all times under each rule, except during a ten-minute startup period in any 4-hour period. During these startup periods, however, solid-fuel heating devices are subject to other restrictions, namely a fuel-content restriction that limits the moisture content of burned wood and restrictions on the type of fuel burned, such as a prohibition on burning any material that normally emits dense smoke, noxious odors, or hazardous air pollutants. EPA also notes that the current, federally-approved SIP includes no opacity limit for residential wood burning, meaning that approval of this provision will result in a net air quality benefit over the status quo. EPA has longstanding guidance that provides recommendations to states concerning the development of alternative emission limitations applicable during startup and shutdown. In a June 12, 2015, 
                    **Federal Register**
                     notice (80 FR 33840) (the “2015 SSM policy”), EPA recommended States consider seven criteria when developing alternative emission limitations to replace automatic or discretionary exemptions from otherwise applicable SIP requirements. These recommended criteria assure the alternative emission limitations meet basic CAA requirements. As discussed above, although the 20% opacity limit does not apply during short periods of startup and refueling, owners and operators of solid-fuel heating devices are subject to alternative fuel-content limitations during these periods. EPA evaluated whether these alternative requirements are consistent with the Agency's 2015 SSM policy, including the seven criteria recommended therein. For the reasons explained below, EPA finds that the opacity limit and other restrictions on fuel are consistent with the recommended criteria set forth in that policy and proposes to approve these provisions into the Oregon SIP as part of this action. First, the opacity limit for residential woodstoves and similar devices and the alternative restrictions on fuel content—which are codified in both the Lane County Code, Section 9.135, and Oakridge Ordinance No. 920, Section Two(3)—apply to a narrow subset of source categories: Solid-fuel heating devices. Second, application of the 20% opacity limit to startup and refueling periods would be technically infeasible because lower temperatures during these periods result in less complete combustion and, therefore, higher opacity. Third, for this source category, EPA believes the startup period is minimized to the greatest extent practicable. The startup period is limited to just ten minutes in every 4-hour period to account for starting the solid fuel burning device and refueling. This ten minute period represents the minimum time necessary to adequately start a fire in a solid fuel burning device. Furthermore, the startup period is limited to once every four hours, which reasonably reflects the amount of time before a residential fire needs additional fuel. With respect to the fourth factor, EPA believes that LRAPA's proposed control strategy, specifically the episodic curtailment program, would effectively prohibit the use of solid fuel burning devices at most locations [17]
                    
                    —and thus largely prohibit use of the startup exemption—during worst-case air quality scenarios. Fifth, the limits on fuel content and type are designed to ensure that all possible steps are taken to minimize the impact of emissions during the startup period. With respect to this factor, EPA also notes that the emission source at issue here is subject to curtailment requirements during periods of high PM2.5
                     ambient air concentration, which would further minimize potential air quality impacts from reliance on the alternative emission limits when the opacity limit does not apply. Similarly, EPA believes the sixth factor—that the alternative emission limit requires operation of the facility in a manner consistent with good practices for minimizing emissions and best-efforts regarding planning, design, and operating procedures—supports approval of the State's chosen control strategy. As noted above, limits on fuel content and type used in conjunction with emission curtailment during air quality episodes represent the best practices available in this context. With respect to the last criterion for alternative emission limits, Oregon has not included a requirement that affected sources document startup periods using properly signed, contemporaneous logs or other evidence. Given that the rule at issue here generally applies to individual homeowners, rather than industrial sources accustomed to complying with such recordkeeping requirements, EPA believes a recordkeeping requirement would impose an unreasonable burden on both regulators implementing the rule and the regulated community, with virtually no enforcement benefit justifying the burden. For all of these reasons, EPA proposes to approve (and incorporate by reference) the Oakridge RWC Ordinance 920—Section Two(3) and the Lane 
                    ( print page 26716)
                    County Code as they apply to the Oakridge area because they are permanent and enforceable SIP-strengthening measures that contribute to continued maintenance of the 2006 PM2.5
                     24-hour NAAQS. Both provisions include limits on emissions that apply during all modes of source operation and impose continuous emission controls on solid-fuel heating devices consistent with the requirements of the CAA applicable to SIP provisions. In addition, they support the maintenance and continued attainment of the PM2.5
                     NAAQS in the Oakridge area. Based on the foregoing evaluation of the Oakridge PM2.5
                     control measures, EPA proposes to determine that the improvement in air quality is reasonably attributable to permanent and enforceable reductions in emissions resulting from implementation of the applicable implementation plan, implementation of applicable Federal air pollutant control regulations, and other permanent and enforceable reductions. D. Fully Approved Maintenance Plan CAA section 107(d)(3)(E)(iv) requires that, for a nonattainment area to be redesignated to attainment, EPA must fully approve a maintenance plan for the area as meeting the requirements of CAA section 175A. The maintenance plan must demonstrate continued attainment of the relevant NAAQS in the area for at least 10 years after our approval of the redesignation. Eight years after redesignation, the state must submit a revised maintenance plan demonstrating attainment for the 10 years following the initial 10-year period. The maintenance plan must also contain a contingency plan to ensure prompt correction of any violation of the NAAQS that occurs after redesignation of the area. 
                    *See*
                     CAA sections 175A(a), (b) and (d). The Calcagni Memo provides additional guidance on the content of a maintenance plan, stating that a maintenance plan should include the following elements: (1) An attainment emissions inventory; (2) a maintenance demonstration showing attainment for 10 years following redesignation; (3) a commitment to maintain and operate an appropriate air quality monitoring network; (4) verification of continued attainment; and (5) a contingency plan to prevent or correct future violations of the NAAQS. In this proposed action, EPA will review requirements (3) and (4) together as part of our evaluation of LRAPA's maintenance plan for the Oakridge area. In conjunction with Oregon's request to redesignate the Oakridge area to attainment, Oregon submitted a SIP revision to provide for maintenance of the 2006 24-hour PM2.5
                     NAAQS through 2035. EPA proposes to approve LRAPA's PM2.5
                     maintenance plan for the Oakridge area. The following paragraphs describe how each of the maintenance plan elements are addressed in the maintenance plan. 1. Attainment Inventory As discussed in the CAA General Preamble (
                    *See*57 FR 13498, April 16, 1992) and the Calcagni Memo, PM2.5
                     maintenance plans should include an attainment emission inventory to identify the level of emissions in the area, which are sufficient to maintain the NAAQS. The maintenance plan attainment inventory should be consistent with EPA's emissions inventory requirements and most recent guidance on emission inventories for nonattainment areas available at the time and should represent emissions during the time period associated with the monitoring data showing attainment.[18]
                    
                     The inventory must also be comprehensive, including emissions from stationary point sources, area sources, mobile sources, and must be based on actual emissions during the appropriate season, if applicable. The EPA-approved 2017 Oakridge Update included projected 2015 PM2.5
                     attainment year emission inventories for the Oakridge NAA. Oregon's January 13, 2022, Oakridge PM2.5
                     maintenance plan submittal provided a revised and updated 2015 attainment year inventory of actual emissions. The year 2015 is one of the years during the time period where the Oakridge area first monitored attainment of the 24-hour PM2.5
                     NAAQS (
                    *See*
                     section III.A of this document).[19]
                    
                     The 2015 maintenance plan attainment year emission inventory is based on emission reduction strategies that were implemented as of 2015. The 2015 maintenance plan attainment year inventory includes emissions of PM2.5, nitrogen oxides (NOX), sulfur dioxide (SO2), ammonia (NH3) and volatile organic compounds (VOCs). The 2015 attainment levels of point, area, on-road mobile and nonroad mobile source emissions are summarized in Tables 3 and 4, along with future year projected emissions for a “horizon year” (a future year at least 10 years from the approval date of the maintenance plan) of 2035, and two interim years of 2025 and 2030. Oregon developed the attainment inventory based on the methods and assumptions presented in detail in Appendix II of the Oakridge PM2.5
                     maintenance plan (“Emision Inventory for 2015 Base Year”). The attainment year inventory is based on typical season and worst-case day (episodic) emissions. The typical season day emissions represent an average daily emission value occurring from November 1 through the end of February. This four-month time period is considered to be the particulate matter season and is when the PM2.5
                     standard has historically been exceeded. The worst-case day emissions represent a day during the PM season when emissions generating activity is at its highest due to meteorological factors like temperature. However, residential woodburning and other area source emissions on worst-case days are lower than on typical season days in the inventory due to woodburning curtailments and outdoor burning bans. This approach is consistent with the PM2.5
                     SIP Requirements Rule in which EPA stated that an episodic period, developed in order to reflect periods of higher emissions during periods of high ambient PM2.5
                     can help, in some situations, to ensure the area's inventory reflects the emissions conditions that led to the nonattainment designation for the area (81 FR 58010, 58030, August 24, 2016). RWC emissions from certified and non-certified woodstoves, fireplaces and pellet stoves continue to be the major source of PM2.5
                     emissions on both typical season days and worst-case winter days contributing to exceedances of the NAAQS.
                    ( print page 26717) Table 3—Oakridge PM
                        2.5
                         Maintenance Plan Emissions Inventories
[In pounds per day]
Source category
2015
                             attainment
2025
                             interim
2030
                             interim
2035
                             maintenance
Difference 
                             from 2015  
                             and 2035**PM**
                            2.5
                              
                            **Typical Season Day**Point
0.0
0.5
0.5
0.5
0.5Area
444.8
364.1
364.0
363.5
−81.3Onroad
34.4
23.0
22.1
22.1
−12.3Nonroad
2.7
2.7
2.7
2.7
0.0Total
481.9
389.8
389.3
388.8
−93.1**PM**
                            2.5
                              
                            **Worst-Case Day**Point
0.0
0.8
0.8
0.8
0.8Area
334.5
250.9
233.8
216.5
−118Onroad
41.4
26.6
26.6
24.7
−16.7Nonroad
2.7
2.7
2.7
2.7
0Total
378.6
281.0
263.9
244.7
−133.9
 Secondary particulate is a very minor contributor to the Oakridge PM2.5
                     air pollution concentrations on both typical season days and worst-case winder days as summarized in Appendix II of the Oakridge PM2.5
                     maintenance plan. Historical speciated PM2.5
                     filter analyses indicate that concentrations of all the precursors groups (NOX, SO2, NH3
                     and VOCs) were determined to be below insignificant thresholds (less than 1.3 μg/m3
                    ). The precursor emission shown in Table 4 are projected to decrease between 2015 and 2035, indicating that precursor emissions will continue to be below insignificant threshold contributions to PM2.5
                     in the future. Table 4—Oakridge PM
                        2.5
                         Maintenance Plan Precursor Emissions Inventories
[In pounds per day]
Source category
2015
                             attainment
2025
                             interim
2030
                             interim
2035
                             maintenance
Difference
                             from 2015  
                             and 2035**NO**
                            X
                              
                            **Typical Season Day**Point
0.0
5.1
5.1
5.1
5.1Area
55.5
48.5
48.5
48.5
−7.0Onroad
613.6
171.2
103.2
87.8
−525.8Nonroad
0.1
0.1
0.1
0.1
0.0Total
669.2
224.9
156.9
141.5
−527.7**NO**
                            X
                              
                            **Worst-Case Day**Point
0.0
8.7
8.7
8.7
8.7Area
42.1
33.9
34.9
32.9
−9.2Onroad
711.3
193.1
127.9
108.8
−602.5Nonroad
0.1
0.1
0.1
0.1
0.0Total
753.5
235.8
171.6
150.5
−603.0**SO**
                            2
                              
                            **Typical Season Day**Point
0.0
0.0
0.0
0.0
0.0Area
11.2
10.3
10.3
10.3
−0.9Onroad
2.4
1.1
1.0
1.0
−1.4Nonroad
0.1
0.1
0.1
0.1
0.0Total
13.7
11.5
11.4
11.4
−2.3**SO**
                            2
                              
                            **Worst-Case Day**Point
0.0
0.0
0.0
0.0
0.0Area
7.0
5.9
5.6
5.2
−1.8Onroad
2.9
1.4
1.2
1.2
−1.7Nonroad
0.1
0.1
0.1
0.1
0.0( print page 26718)Total
10.0
7.4
6.9
6.5
−3.5**VOC Typical Season Day**Point
0.0
0.4
0.4
0.4
0.4Area
507.0
349.3
346.0
341.7
−165.3Onroad
522.7
173.7
15.7
13.2
−509.5Nonroad
5.2
5.1
5.1
5.1
−0.1Total
1,034.9
528.5
367.2
360.4
−674.5**VOC Worst-Case Day**Point
0.0
0.8
0.8
0.8
0.8Area
321.2
179.3
165.1
150.5
−170.7Onroad
543.2
183.2
18.8
15.9
−527.3Nonroad
5.2
5.1
5.1
5.1
−0.1Total
869.6
368.4
189.8
172.3
−697.3**NH**
                            3
                              
                            **Typical Season Day**Point
0.0
0.0
0.0
0.0
0.0Area
30.0
25.4
25.4
25.4
−4.6Onroad
9.7
7.4
4.4
4.3
−5.4Nonroad
0.1
0.1
0.1
0.1
0.0Total
39.8
32.9
29.9
29.8
−10.0**NH**
                            3
                              
                            **Worst-Case Day**Point
0.0
0.0
0.0
0.0
0.0Area
18.2
13.5
12.6
11.8
−6.4Onroad
12.0
9.1
5.4
5.3
−6.7Nonroad
0.1
0.1
0.1
0.1
0.0Total
30.3
22.7
18.1
17.2
−13.1
 In addition to the precursor assessment, LRAPA assessed the condensable and filterable fractions of the PM2.5
                     emission inventory. Since condensable and filterable emissions currently are not required to be reported for the mobile source and the residential wood combustion portion of the inventory and EPA's best tools to date do not have a declarative answer for the condensable emissions portion for these sources, there was no information to report. In addition, condensable and filterable information for the other source categories were similarly either unavailable or not applicable. Based on available data sources, therefore, the condensible portion of PM2.5
                     was reported as zero in the 2015 emissions inventory and the projected inventories do not include separately reported filterable and condensable components of direct PM2.5
                     emissions. EPA has reviewed the results, procedures, and methodologies for the Oakridge area 2015 attainment emissions inventories and proposes to find that they are based on the most current and accurate information available to LRAPA at the time they were developed. Based on our review of the emissions inventories Oregon provided in its January 13, 2022 submittal, we propose to find that LRAPA prepared an adequate attainment inventory for the Oakridge area.[20] 2. Maintenance Demonstration CAA section 175A requires a state seeking redesignation to attainment to submit a SIP revision to provide for maintenance of the NAAQS in the area “for at least 10 years after the redesignation.” A state can make this demonstration by either showing that future emissions of a pollutant or its precursors will not exceed the level of the attainment inventory, or by modeling to show that the future mix of sources and emissions rates will not cause a violation of the NAAQS.[21] In its maintenance demonstration for the Oakridge area, LRAPA elected to demonstrate maintenance of the 2006 PM2.5
                     NAAQS for at least 10 years following redesignation using the attainment inventory method. LRAPA developed projected inventories, provided in Tables 3 and 4 of this document, to show that the Oakridge area will remain in attainment through the year 2035. These projected inventories, covering interim years 2025 and 2030 and a horizon year of 2035, show that future emissions of direct PM2.5
                     throughout the nonattainment area will remain at or below the 2015 attainment-level emissions for the 2006 24-hour PM2.5
                     NAAQS. The projected emissions inventories in the Oakridge PM2.5
                     maintenance plan 
                    ( print page 26719)
                    address four major source categories: Point, area, onroad mobile and nonroad mobile. Oregon estimated future year emission inventories using the latest socioeconomic growth indictors and applying emissions reduction benefits from adopted control strategies when appropriate. A detailed description of the 2015 base year inventory and the 2025, 2030 and 2035 projected inventories can be found in Appendix III of LRAPA's January 13, 2022, PM2.5
                     maintenance plan submittal, which is in the docket for this action. As discussed in the Oakridge PM2.5
                     maintenance plan, direct PM2.5
                     emissions estimates for stationary point sources reflect actual emissions for both industrial point sources in Oakridge. The Oakridge Sand & Gravel ready-mix concrete plant and rock crusher did not operate in Oakridge in 2015, resulting in actual 2015 emissions that were zero. In addition, the ready-mix concrete plant air discharge permit was terminated on January 24, 2014, resulting in zero emissions in the 2015 and projected year emission inventories. Future year emissions were therefore based on the January 2011 PM2.5
                     emissions at this source. Areawide sources occur over a wide geographic area with the most significant emissions resulting from RWC sources such as fireplaces, woodstoves and pellet stoves. These residential wood heating devices are commonly used to heat homes in Oakridge since natural gas is not available in this area. The permanent and enforceable RWC control strategies are discussed in Section III.C. of this document. The only other area source category with potentially significant emissions is outdoor burning, which is banned in Lane County from November-February. Emissions for these categories are derived using various surveys, PM2.5
                     emission factors and other methodologies. Emissions from on-road mobile sources (exhaust, brake wear and tire wear), which include passenger vehicles, buses, and trucks, were estimated using MOVES2014a. Traffic growth in Vehicle-Miles Traveled (VMT) was based on transportation modeling by the Lane Council of Governments (LCOG) and the Oregon Department of Transportation (ODOT). LRAPA confirmed re-entrained road dust calculations for both paved and unpaved roads using AP-42 protocols. Federal control measures included in the MOVES2014a modeling are all Federal measures that affect the fleets and fuels used in future years once implemented by EPA. The nonroad emissions from railroads were calculated using the EPA NONROAD2008a emission protocol. The National Emissions Inventories (NEIs) for Lane County indicate a significant decrease in locomotive emissions from 2008 to 2014 (40.09 tons/year and 18.26 tons/year, respectively). The 2015 PM2.5
                     railroad emissions have been adjusted to reflect the locomotive emission reductions as seen in the 2014 NEI data. Future year emissions are based on the adjusted 2014 and 2017 NEI data. All other Oakridge nonroad mobile sources are categorized by LRAPA as insignificant during the PM2.5
                     winter season. EPA has reviewed the documentation provided by Oregon for developing the projected 2025, 2030 and 2035 emissions inventories for the Oakridge PM2.5
                     NAA. Based on our review, EPA finds that the projected inventories were developed using appropriate procedures, comprehensively address all source categories in the Oakridge area, and sufficiently account for PM2.5
                     projected actual emissions. These inventories indicate a decrease in PM2.5
                     and precursor emissions throughout the maintenance period, therefore EPA proposes to determine that the projected emissions inventories in the maintenance plan sufficiently demonstrate that the Oakridge PM2.5
                     area will continue to attain the 2006 24-hour PM2.5
                     standard throughout the maintenance period. 3. Monitoring Network and Verification of Continued Attainment Once a nonattainment area has been redesignated to attainment, the state must continue to operate an appropriate air quality monitoring network, in accordance with 40 CFR part 58, to verify the attainment status of the area. The maintenance plan should contain provisions for continued operation of air quality monitors that will provide such verification. In the Oakridge PM2.5
                     maintenance plan, LRAPA noted that it currently operates a regulatory monitor (the Willamette Center since 1989) in the Oakridge NAA and committed to continue operating a regulatory monitoring network through the year 2035 in order to verify continued attainment of the PM2.5
                     NAAQS and track the progress of the maintenance plan. LRAPA also stated it will continue operation of the PM2.5
                     monitoring network as outlined in the Oregon Annual Ambient Criteria Pollutant Air Monitoring Network Plan (ANP) and any modification to the monitoring network will be done in consultation with ODEQ and EPA Region 10. ODEQ and LRAPA will work with EPA each year through the air monitoring network review process (per 40 CFR part 58) to determine the adequacy of the monitoring network.[22] Oregon remains obligated to continue to quality-assure monitoring data and enter all data into AQS in accordance with Federal guidelines. LRAPA will review the air monitoring results and design values each year to verify continued attainment. LRAPA will determine annually if exceptional events influenced the continued attainment of the 2006 24-hour PM2.5
                     NAAQS and need to be documented. If needed, ODEQ and LRAPA will coordinate and provide exceptional events documentation to EPA Region 10 for review. EPA proposes to determine that the Oakridge PM2.5
                     maintenance plan contains adequate provisions for continued operation of an air quality monitoring network and a commitment to annually verify continued attainment of the 2006 24-hour PM2.5
                     NAAQS for the Oakridge area. 4. Contingency Plan CAA section 175A(d) requires that a maintenance plan also include contingency provisions, as necessary, to promptly correct any violation of the NAAQS that occurs after redesignation of the area to attainment. For the purposes of CAA section 175A, a state is not required to have fully adopted contingency measures that will take effect without further action by the state in order for the maintenance plan to be approved. However, the contingency plan is an enforceable part of the SIP and should ensure that contingency measures are adopted expeditiously once they are triggered. The contingency plan should discuss the measures to be adopted and a schedule and procedure for adoption and implementation. The contingency plan must require that the state will implement all measures contained in the part D nonattainment plan for the area prior to redesignation. The state should also identify the specific indicators, or triggers, which will be used to determine when the contingency plan will be implemented.[23] The Oakridge PM2.5
                     maintenance plan outlines the procedures for the adoption and implementation of contingency measures to further reduce emissions should a violation of the 2006 24-hour PM2.5
                     NAAQS occur. If the PM2.5
                     design 
                    ( print page 26720)
                    value indicates a violation of the standard, after consideration of any exceptional events, the following contingency strategies, or equivalent, will be implemented by LRAPA and the City of Oakridge: Stricter green-yellow-red advisory program,[24]
                    
                     with more red advisory days each winter, by reducing the red advisory thresholds by 3 μg/m3
                     PM2.5.
                     This is projected to increase the average number of potential red advisory days by three to five additional days per year. Prohibition of fireplace use on yellow advisory days (in addition to the existing prohibition on red advisory days). While these measures do not need to be fully adopted by LRAPA prior to the occurrence of a NAAQS violation, LRAPA commits to adopting and implementing the necessary contingency measures as expeditiously as possible, but not later than one year after a violation, based on confirmed quality-assured data. Any contingency measures adopted and implemented will become part of the control measures in the next revised maintenance plan submitted to EPA for approval. LRAPA will evaluate all appropriate data including air quality data, meteorological data, evaluation of wood smoke programs and information on unusual weather events (
                    *e.g.,*
                     wildfires or winter power outages) and other data to determine the cause of the violation. LRAPA will perform this evaluation within three months of the determination of a violation. Where appropriate, LRAPA will follow EPA's exceptional events rules and guidance if it is determined that an exceptional event contributed to the violation.[25] Based on our analysis of Oregon's submittal, we propose to find that the contingency measure provisions provided in the Oakridge PM2.5
                     maintenance plan are sufficient and meet the requirements of CAA section 175A(d). E. Transportation Conformity and Motor Vehicle Emissions Budgets Transportation conformity is required by CAA section 176(c). EPA's conformity rule at 40 CFR part 93, subpart A requires that transportation plans, programs, and projects conform to SIPs and establishes the criteria and procedures for determining whether they conform. Conformity to a SIP means that transportation activities will not produce new air quality violations, worsen existing violations, or delay timely attainment of the NAAQS. Thus, EPA's conformity rule requires a demonstration that emissions from a Metropolitan Planning Organization's Regional Transportation Plan and Transportation Improvement Program, involving Federal Highway Administration or Federal Transit Administration funding or approval, are consistent with the MVEB(s) contained in a control strategy SIP revision or maintenance plan (40 CFR 93.101, 93.118, and 93.124). A MVEB is the level of mobile source emissions of a pollutant relied upon in the attainment or maintenance demonstration to attain or maintain compliance with the NAAQS in the nonattainment or maintenance area. A PM2.5
                     maintenance plan should identify MVEBs for direct PM2.5, NOX
                     and all other PM2.5
                     precursors from on-road mobile source emissions that are determined to significantly contribute to PM2.5
                     levels in the area.[26]
                    
                     All direct PM2.5
                     SIP budgets should include direct PM2.5
                     motor vehicle emissions from tailpipe, brake wear and tire wear. A State must also consider whether re-entrained paved and unpaved road dust are significant contributors and should be included in the direct PM2.5
                     budget.[27] It should be noted that Oakridge is considered an isolated rural nonattainment area within the meaning of 40 CFR 93.109(g), so transportation conformity determinations are only required when a non-exempt Federal Highway Administration or Federal Transit Administration funded project is funded or approved.[28] The Oakridge PM2.5
                     maintenance plan includes direct PM2.5
                     MVEBs for the attainment year (2015), two interim years (2025 and 2030) and the maintenance horizon year (2035). 
                    *See*
                     Table 5, below. On February 8, 2018, EPA approved a 2015 attainment year PM2.5
                     MVEB of 22.2 lb/day (83 FR 5537). The projected MVEBs (2025, 2030 and 2035) reflect the total on-road PM2.5
                     worst-case day emissions (a sum of primary exhaust, brake wear and tire wear), plus a portion of the available safety margin to accommodate technical uncertainties due to model updates and inputs into the EPA MOVES model and travel forecasting models as well as potential changes to regional transportation plans. A safety margin is the amount by which the total projected PM2.5
                     emissions from all sources are less than the total emissions that would satisfy the NAAQS for the 2015 attainment year. With the safety margin applied to the future year MVEB, the budgets still demonstrate maintenance of the 2006 24-hour PM2.5
                     NAAQS. Oregon used the Motor Vehicle Emissions Simulator model, MOVES2014a, during the development of the maintenance plan and executed it with locally developed inputs representative of wintertime calendar year 2015 conditions and future projections in order to appropriately calculate the budgets. MOVES2014a was the accepted model when this work began. EPA recently released MOVES3, but since sufficient work had taken place on this SIP with MOVES2014a, we are accepting that mobile model in this submittal (86 FR 1106, 1108, January 7, 2021). Traffic growth in VMT for the Oakridge NAA is based on transportation modeling by Lane County, LCOG and ODOT. The mobile source emissions, in total, were modeled to steadily decrease between 2015 and 2035 as a result of cleaner vehicles and cleaner fuels. The MVEBs are based on the control measures in the maintenance plan and consistent with maintaining the 2006 24-hour PM2.5
                     NAAQS. As determined in the 2016 attainment plan approval (83 FR 5537, February 8, 2018), secondary particulate are still minor contributors to the Oakridge PM2.5
                     air pollution concentrations on worst-case winter days as summarized in section III.D.1. Oregon excluded paved road dust emissions and NOX
                     emissions from the MVEB in accordance with 40 CFR 93.102(b)(3). Vehicle emissions of SO2
                     and NH3
                     were also found to contribute minimally to PM2.5
                     in the area and therefore the maintenance plan does not include MVEBs for these precursors in accordance with 40 CFR 93.102(b)(2)(v). 
                    *See*
                     Appendix IV of LRAPA's Oakridge PM2.5
                     maintenance plan, in the docket for this action, for further analysis of the MVEB pollutants and precursors. Therefore, based on its analysis, LRAPA set the Oakridge direct PM2.5
                     MVEBs for 2015, 2025, 2030 and 2035 as provided in Table 5 of this proposed action. According to EPA's conformity rule, the emissions budget acts as a ceiling on emissions in the year for which it is defined or until a SIP revision modifies the budget.[29] 
 
 Table 5—Direct PM
                        2.5
                         MVEBs for the Oakridge PM
                        2.5
                         NAA
Motor vehicle emissions budgets
Year2015
2025
2030
2035Direct PM
                            2.5
                             (lb/day)
22.2
8.2
7.2
6.5
 For MVEBs to be approvable, they must meet, at a minimum, EPA's adequacy criteria (40 CFR 93.118(e)(4)). EPA's process for determining adequacy of a budget consists of three basic steps: (1) Notifying the public of a SIP submittal; (2) providing the public the opportunity to comment on the budget during a public comment period; and (3) making a finding of adequacy or inadequacy. The process for determining the adequacy of a submitted budget is codified at 40 CFR 93.118(f). EPA can notify the public by either posting an announcement that EPA has received SIP budgets on EPA's adequacy website (40 CFR 93.118(f)(1)), or via a 
                    **Federal Register**
                     notice of proposed rulemaking when EPA reviews the adequacy of an implementation plan budget simultaneously with its review and action on the SIP itself (40 CFR 93.118(f)(2)). Today, we are notifying the public that EPA will be reviewing the adequacy of the 2015, 2025, 2030 and 2035 budgets in the Oakridge PM2.5
                     maintenance plan. The public has a 30-day comment period as described in the 
                    **DATES**
                     section of this document. After this comment period, EPA will indicate whether the budgets are adequate via the final rulemaking on this proposed action or on the adequacy website, according to 40 CFR 93.118(f)(2)(iii). The details of EPA'evaluation of the budget for compliance with the budget adequacy criteria of 40 CFR 93.118(e) are provided in a separate memorandum included with the docket for this rulemaking.[30]
                    
                     As noted earlier, the public comment period for EPA's adequacy finding will be concurrent with the public comment period for this proposed action on the Oakridge PM2.5
                     Maintenance Plan. Based on the information presented in the Oakridge PM2.5
                     maintenance plan and our adequacy review to date, we propose to find that Oregon has evaluated the appropriate pollutants and precursors and appropriately established MVEBs for direct PM2.5
                     emissions. EPA has reviewed the Oakridge PM2.5
                     maintenance plan's MVEBs and found them to be consistent with the control measures in the SIP and consistent with maintenance of the 2006 24-hour PM2.5
                     NAAQS within the Oakridge area through 2035. We propose to approve the MVEBs in the Oakridge PM2.5
                     maintenance plan as meeting the requirements of the CAA and EPA regulations. F. State Rule Changes To Reflect the Redesignation Oregon adopted maintenance plans for both the Oakridge PM2.5
                     and Oakridge PM10
                     area in the same state rulemaking package and submitted them as a single SIP submittal to EPA. This single submittal includes changes to LRAPA rules to reflect the anticipated redesignation of both areas. Today's action addresses the Oakridge PM2.5
                     area, and we are addressing the Oakridge PM10
                     area in a separate action. However, in today's action, for the sake of simplicity, we are proposing to approve all updates to LRAPA rules to reflect the anticipated redesignation of both areas. We believe this is appropriate because we intend to finalize our proposed actions on both areas within the same time frame. In today's action, EPA is proposing to approve revisions to LRAPA's Title 29 
                    *Designation of Air Quality Areas,*
                     Section 29-0030(2) 
                    *Designation of Nonattainment Areas*
                     and Section 29-0040(3) 
                    *Designation of Maintenance Areas.*
                     These revisions will remove the Oakridge PM2.5
                     nonattainment areas from the list of PM2.5
                     nonattainment areas and add them to the list of PM2.5
                     maintenance areas within the federally-approved Oregon SIP. EPA is also proposing to approve minor editorial changes to LRAPA's Title 29 
                    *Designation of Air Quality Areas,*
                     Section 29-0010 
                    *Definitions*
                     and Section 29-0310 
                    *Designation of Reattainment Areas,*
                     to consistently refer to the “Oakridge PM2.5
                     Maintenance Area” rather than the “Oakridge PM2.5
                     Non-attainment area.” [31] IV. Proposed Action EPA proposes to redesignate the Oakridge, Oregon PM2.5
                     NAA, and proposes approval of the associated maintenance plan for the area. If this proposal is finalized, the designation status of the Oakridge, Oregon PM2.5
                     NAA under 40 CFR part 81 will be revised to attainment upon the effective date of that final action. EPA proposes to approve and incorporate by reference into the Oregon SIP, the submitted revisions to LRAPA Title 29 Sections 29-0010, 29-0020, 29-0030(2), 29-0040(3), 29-0050, 29-0060, 29-0070, 29-0080, 29-0090, 29-0300, 29-0310 and 29-0320, state effective November 18, 2021. In addition, EPA proposes to approve and incorporate into the SIP specific sections of the local rule submitted on January 20, 2017, and the local rule submitted on January 13, 2022, as part of the maintenance plan to the extent set forth in this document. EPA also proposes to take final agency action on Oregon's exceptional event demonstration for the Oakridge PM10
                     monitor as discussed in this action. Finally, we propose that the Oakridge PM2.5
                     maintenance plan's MVEBs meet applicable CAA requirements for maintenance plans and transportation conformity requirements. With this action, we are starting the adequacy process for these proposed MVEBs and opening a public comment period. We note that the January 13, 2022 submittal also includes the Oakridge PM10
                     redesignation and maintenance plan and additional revisions to LRAPA's Title 29 rules, which EPA will address in a separate action. V. Incorporation by Reference In this document, EPA proposes to include, in a final rule, regulatory text that includes incorporation by reference. In accordance with the requirements of 1 CFR 51.5, EPA proposes to incorporate by reference the provisions described in Section IV of this document, specifically (1) The Lane County Code Chapter 9—
                    *Restriction on Use of Solid Fuel Space Heating Devices,*
                     Sections 9.120-9.140, (2) the City of Oakridge Ordinance No. 920—
                    *An Ordinance Amending Section 7 of Ordinance 914 and Adopting New Standards for the Oakridge Air 
                        ( print page 26722)
                        Pollution Control Program;*
                     Section Two(3)—
                    *Solid Fuel Burning Devices—Prohibitions*
                     and (3) revisions to LRAPA's Title 29 rules as described in Section IV of this document. EPA has made, and will continue to make, these documents generally available through 
                    *https://www.regulations.gov*
                     and at the EPA Region 10 Office (please contact the person identified in the 
                    **FOR FURTHER INFORMATION CONTACT**
                     section of this preamble for more information). VI. Statutory and Executive Orders Review Under the CAA, redesignation of an area to attainment and the accompanying approval of a maintenance plan under section 107(d)(3)(E) are actions that affect the status of a geographical area and do not impose any additional regulatory requirements on sources beyond those imposed by state law. A redesignation to attainment does not in and of itself create any new requirements, but rather results in the applicability of requirements contained in the CAA for areas that have been redesignated to attainment. Moreover, the Administrator is required to approve a SIP submittal that complies with the provisions of the CAA and applicable Federal regulations. 42 U.S.C. 7410(k); 40 CFR 52.02(a). Thus, in reviewing SIP submittals, EPA's role is to approve state choices, provided that they meet the criteria of the CAA. Accordingly, this proposed action merely proposes to approve a State plan and State law as meeting Federal requirements and does not impose additional requirements beyond those already imposed by State law. For that reason, this proposed action: Is not a “significant regulatory action” subject to review by the Office of Management and Budget under Executive Orders 12866 (58 FR 51735, October 4, 1993) and 13563 (76 FR 3821, January 21, 2011);
                Does not impose an information collection burden under the provisions of the Paperwork Reduction Act (44 U.S.C. 3501 
                    *et seq.*);
                Is certified as not having a significant economic impact on a substantial number of small entities under the Regulatory Flexibility Act (5 U.S.C. 601 
                    *et seq.*);
                Does not contain any unfunded mandate or significantly or uniquely affect small governments, as described in the Unfunded Mandates Reform Act of 1995 (Pub. L. 104-4);
                Does not have federalism implications as specified inExecutive Order 13132 (64 FR 43255, August 10, 1999);
                Is not an economically significant regulatory action based on health or safety risks subject toExecutive Order 13045 (62 FR 19885, April 23, 1997);
                Is not a significant regulatory action subject toExecutive Order 13211 (66 FR 28355, May 22, 2001);
                Is not subject to requirements of Section 12(d) of the National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272 note) because application of those requirements would be inconsistent with the CAA; and
                Does not provide EPA with the discretionary authority to address, as appropriate, disproportionate human health or environmental effects, using practicable and legally permissible methods, underExecutive Order 12898 (59 FR 7629, February 16, 1994). In addition, the SIP is not approved to apply on any Indian reservation land or in any other area where EPA or an Indian tribe has demonstrated that a tribe has jurisdiction. In those areas of Indian country, this rule does not have tribal implications as specified by Executive Order 13175 (65 FR 67249, November 9, 2000). List of Subjects 40 CFR Part 52 Environmental protection
Air pollution control
Carbon monoxide
Incorporation by reference
Intergovernmental relations
Lead
Nitrogen dioxide
Ozone
Particulate matter
Reporting and recordkeeping requirements
Sulfur oxides
Volatile organic compounds 40 CFR Part 81 Environmental protection
Air pollution control
National parks
Wilderness areas
 Authority:
                    42 U.S.C. 7401 
                        *et seq.* Dated: April 25, 2022. Michelle L. Pirzadeh, Acting Regional Administrator, Region 10.


# Footnotes

1.
    
                         
                        *See*
                         part D of title I of the Clean Air Act and EPA's Fine Particulate Matter National Ambient Air Quality Standards: State Implementation Plan Requirements (72 FR 20586, April 25, 2007). Back to Citation
 2.
    
                         
                        *See*
                         “State Implementation Plans; General Preamble for the Implementation of Title I of the Clean Air Act Amendments of 1990,” 57 FR 13498, April 16, 1992. Back to Citation
 3.
    
                         We note that the January 13, 2022 submittal also includes the Oakridge PM10
                         redesignation and maintenance plan and revisions to LRAPA's Title 29 rules, which EPA will address in a separate action. Back to Citation
 4.
    
                         
                        *See*40 CFR part 50 and 40 CFR part 50, appendix N. Back to Citation
 5.
    
                         AQS is EPA's official repository of ambient air data. Back to Citation
 6.
    
                         Under CAA section 319(b), an exceptional event means an event that (i) affects air quality; (ii) is not reasonably controllable or preventable; (iii) is an event caused by human activity that is unlikely to recur at a particular location or a natural event; and (iv) is determined by EPA under the process established in regulations promulgated by EPA in accordance with section 319(b)(2) to be an exceptional event. For the purposes of section 319(b), an exceptional event does not include (i) stagnation of air masses or meteorological inversions; (ii) a meteorological event involving high temperatures or lack of precipitation; or (iii) air pollution relating to source noncompliance. Back to Citation
 7.
    
                         72 FR 13560, March 22, 2007. Back to Citation
 8.
    
                         81 FR 68216 (October 3, 2016). We refer herein to the 2016 revision as the “Exceptional Events Rule.” Back to Citation
 9.
    
                         40 CFR 50.14(b)(4). Back to Citation
 10.
    
                         Calcagni Memo, 3; 
                        *Wall*
                         v. 
                        *EPA,*
                         265 F.3d 426, 438 (6th Cir. 2001); and 
                        *Southwestern Pennsylvania Growth Alliance*
                         v. 
                        *Browner,*
                         144 F.3d 984, 989-990 (6th Cir. 1998). Back to Citation
 11.
    
                         
                        *See*
                         the General Preamble for further explanation of these requirements. 57 FR 13498 (April 16, 1992). Back to Citation
 12.
    
                         
                        *See*75 FR 36023, 36026 (June 24, 2010) and citations within. Back to Citation
 13.
    
                         The LRAPA portion of the federally-approved Oregon SIP can be viewed at 
                        *https://www.epa.gov/​sips-or/​epa-approved-regulations-oregon-sip.* Back to Citation
 14.
    
                         
                        *See*81 FR 58010 (August 24, 2016). Codified at 40 CFR part 51, subpart Z. Back to Citation
 15.
    
                         
                        *See*
                         Section 188(c)(1) of the CAA, 42 U.S.C. 7513(c)(1), and 40 CFR 51.1004(a)(1). 
                        *See also*
                         Identification of Nonattainment Classification and Deadlines for Submission of State Implementation Plan (SIP) Provisions for the 1997 Fine Particle (PM2.5) National Ambient Air Quality Standard (NAAQS) and 2006 PM2.5
                         NAAQS (June 2, 2014), 79 FR 31566, 31567-68. Back to Citation
 16.
    
                         
                        *See*40 CFR 51.160, 51.161, 51.165, and 51.166. 
                        *See also*
                         EPA's proposed approval of Oregon nonattainment NSR program (March 22, 2017, 82 FR 14654, 14663) and EPA's final approval (October 11, 2017, 82 FR 47122). Back to Citation
 17.
    
                         Exemptions from the use of woodstoves and similar devices during curtailment periods are available on an annual basis if the woodstove or similar device is the sole source of heat in the residence and/or due to economic need based on specified criteria. Back to Citation
 18.
    
                         
                        *See*
                         Calcagni Memo at 8. Back to Citation
 19.
    
                         83 FR 5537, February 8, 2018. Back to Citation
 20.
    
                         
                        *See*
                         “Emissions Inventory Guidance for Implementation of Ozone and Particulate Matter National Ambient Air Quality Standards (NAAQS) and Regional Haze Regulations,” May 2017, available at 
                        *https://www.epa.gov/​sites/​default/​files/​2017-07/​documents/​ei_​guidance_​may_​2017_​final_​rev.pdf.* Back to Citation
 21.
    
                         
                        *See*
                         Calcagni Memo, pages 9-10. Back to Citation
 22.
    
                         
                        *See*
                         EPA's February 22, 2022 approval of Oregon's 2021 Annual Ambient Criteria Pollutant Air Monitoring Network Plan, in the docket for this action. Back to Citation
 23.
    
                         
                        *See*
                         Calcagni Memo at 12. Back to Citation
 24.
    
                         LRAPA implements an advisory system that designates days as green, yellow, or red when 24-hour PM levels reach certain designated thresholds. During a red advisory day, LRAPA prohibits the use of any solid fuel space heating device that emits visible emissions into the air outside of the building housing the device unless a specific exemption has been granted. Back to Citation
 25.
    
                         Treatment of Data Influenced by Exceptional Events, October 3, 2016, 81 FR 68216. Back to Citation
 26.
    
                         
                        *See*40 CFR 93.102(b)(2)(iv)-(v) and (b)(3). Back to Citation
 27.
    
                         
                        *See*40 CFR 93.102(b), 93.122(f). Back to Citation
 28.
    
                         
                        *See*40 CFR 93.109(g). Back to Citation
 29.
    
                         
                        *See*40 CFR 93.118. Back to Citation
 30.
    
                         
                        *See*
                         EPA memorandum titled, “EPA Region 10 Adequacy Review of Motor Vehicle Emissions Budgets in Oakridge PM2.5
                         Maintenance Plan”, dated April 6, 2022. Back to Citation
 31.
    
                         On January 13, 2022, Oregon also submitted LRAPA Title 29 Sections 0020, 0050-0090, 0300 and 0320. Oregon made no changes to these sections, except for the State effective date. EPA has reviewed these rules and approved them in a previous action (83 FR 50274, March 23, 2018). Back to Citation


[FR Doc. 2022-09256 Filed 5-4-22; 8:45 am] BILLING CODE 6560-50-P