Adequacy Status of the Klamath Falls, Oregon Submitted 2006 24-Hour PM2.5 NAAQS Redesignation Request and Maintenance Plan Budgets for Transportation Conformity Purposes

<RULE> ENVIRONMENTAL PROTECTION AGENCY <CFR>40 CFR Part 52</CFR> <DEPDOC>[EPA-R10-OAR-2025-0052; FRL-12541-01-R10]</DEPDOC> <SUBJECT> Adequacy Status of the Klamath Falls, Oregon Submitted 2006 24-Hour PM <E T="0735">2.5</E> NAAQS Redesignation Request and Maintenance Plan Budgets for Transportation Conformity Purposes </SUBJECT> <HD SOURCE="HED">AGENCY:</HD> Environmental Protection Agency (EPA). <HD SOURCE="HED">ACTION:</HD> Determination of adequacy. <SUM> <HD SOURCE="HED">SUMMARY:</HD> The EPA is notifying the public that we have found the motor vehicle emissions budgets for the Klamath Falls, Oregon 2006 24-hour fine particulate matter standard nonattainment area adequate for transportation conformity purposes. The budgets were submitted on August 20, 2024, as part of Oregon's Klamath Falls Redesignation Request and Maintenance Plan. As a result of our finding, the Klamath Falls area must use these budgets for future transportation conformity determinations. </SUM> <DATES> <HD SOURCE="HED">DATES:</HD> This finding is effective September 5, 2025. </DATES> <FURINF> <HD SOURCE="HED">FOR FURTHER INFORMATION CONTACT:</HD> Tess Bloom, 1200 6th Avenue, Suite 155, Seattle, WA 98101; <E T="03">bloom.tess@epa.gov</E> or 206-553-6362. </FURINF> <SUPLINF> <HD SOURCE="HED">SUPPLEMENTARY INFORMATION:</HD> Throughout this document, “we” and “our” refer to the EPA. This document is an announcement of a finding that we have already made. The EPA Region 10 sent a letter to the Oregon Department of Environmental Quality on April 25, 2025 stating that the 2017 and 2037 fine particulate matter (PM <E T="52">2.5</E> ) and nitrogen oxides (NO <E T="52">X</E> ) motor vehicle emissions budgets in the Klamath Falls 2006 24-hour PM <E T="52">2.5</E> national ambient air quality standards (NAAQS) nonattainment area, submitted as part of Oregon's August 20, 2024, Redesignation Request and Maintenance Plan, are adequate. The finding is available in the docket for this action and at the EPA's conformity website: <E T="03">https://www.epa.gov/state-and-local-transportation/adequacy-review-state-implementation-plan-sip-submissions-conformity</E> /. The adequate motor vehicle emissions budgets are provided in the following table: <GPOTABLE COLS="4" OPTS="L2,nj,i1" CDEF="16C,12C,16C,12C"> <TTITLE> Adequate Motor Vehicle Emissions Budgets for the 24-Hour PM <E T="0732">2.5</E> NAAQS in the Klamath Falls Nonattainment Area for a Typical Season Day (TSD) </TTITLE> <CHED H="1"> PM <E T="0732">2.5</E> emissions (lbs/day) </CHED> <CHED H="2">2017 Attainment year</CHED> <CHED H="2">2037 Future year</CHED> The motor vehicle emissions budgets for the 2037 future year will be 77 and 1448 lbs/day for PM <E T="52">2.5</E> and NO <E T="52">X</E> respectively. Oregon's Klamath Falls Redesignation Request and Maintenance Plan established a safety margin for the 2037 future year motor vehicle emissions budgets along with additional margin allocated from emissions reductions from woodstoves. The safety margin was applied to the 2037 future year motor vehicle emissions budgets to account for emissions from future transportation projects. The submission establishes that 411 woodstoves were removed after 2017 from the Klamath Falls nonattainment area which led to decreases in PM <E T="52">2.5</E> and NO <E T="52">X</E> emissions. To provide an extra safety margin for mobile vehicle emissions, a portion of the emissions that would have occurred from the 411 woodstoves that were removed was allocated to the 2037 future year motor vehicle emissions budgets. Transportation conformity is required by Clean Air Act section 176(c). The EPA's Transportation Conformity Rule requires that transportation plans, transportation improvement programs, and projects conform to state air quality implementation plans (SIPs) and establishes the criteria and procedures for determining whether or not they do. <SU>1</SU> <FTREF/> 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. <FTNT> <SU>1</SU>  40 CFR part 93, subpart A. </FTNT> The criteria by which we determine whether a SIP's motor vehicle emission budgets are adequate for conformity purposes are outlined in 40 CFR 93.118(e)(4). We've described our process for determining the adequacy of submitted SIP budgets in our July 1, 2004 (69 FR 40004) preamble starting at page 40038 and we used the information in these resources in making our adequacy determination. Please note that an adequacy review is separate from the EPA's completeness review and should not be used to prejudge the EPA's ultimate action on the redesignation request and maintenance plan. <HD SOURCE="HED">Authority:</HD> 42 U.S.C. 7401 <E T="03">et seq.</E> <SIG> <DATED>Dated: August 8, 2025.</DATED> <NAME>Emma Pokon,</NAME> Regional Administrator, Region 10. </SIG> </SUPLINF> <FRDOC>[FR Doc. 2025-15991 Filed 8-20-25; 8:45 am]</FRDOC> </RULE>