# California.
**AGENCY:**
Environmental Protection Agency (EPA).
**ACTION:**
Final rule.
**SUMMARY:**
The Environmental Protection Agency (EPA) is finalizing a one-year extension of the “Extreme” attainment date from June 15, 2024 to June 15, 2025, for the 1997 ozone national ambient air quality standards (NAAQS) to the Riverside County (Coachella Valley), California ozone nonattainment area (“Coachella Valley”). The EPA is also taking final action on the exceptional event request submitted by the California Air Resources Board (CARB) on October 11, 2024. This action is based on the EPA's concurrence on the exceptional events demonstration, which removed from the design value (DV) calculation the wildfire-influenced data recorded at the Palm Springs—Fire Station monitor (AQS Site ID #060655001) on July 14-15, 2023, and the extension request submitted by the State of California.
**DATES:**
This rule is effective October 6, 2025.
**ADDRESSES:**
The EPA has established a docket for this action under Docket ID No. EPA-R09-OAR-2024-0570. All documents in the docket are listed on the *https://www.regulations.gov* website. Although listed in the index, some information is not publicly available, *e.g.,* Confidential Business Information (CBI) or other information whose disclosure is restricted by statute. Certain other material, such as copyrighted material, is not placed on the internet and will be publicly available only in hard copy form. Publicly available docket materials are available through *https://www.regulations.gov,* or please contact the person identified in the *FOR FURTHER INFORMATION CONTACT* Tom Kelly, Geographic Strategies and Modeling Section (AIR-2-2), EPA Region IX, 75 Hawthorne Street, San Francisco, CA 94105; phone: (415) 972-3856; or email: *[email protected].*
**SUPPLEMENTARY INFORMATION:**
Throughout this document, “we,” “us,” and “our” refer to the EPA.
**Table of Contents**
I. Proposed Action
II. Public Comments and the EPA's Responses
III. The EPA's Action
IV. Statutory and Executive Order Reviews
**I. Proposed Action**
On March 17, 2025, [^1] the EPA proposed to grant California's request for a one-year extension of the Extreme attainment date for the 1997 ozone NAAQS, from June 15, 2024, to June 15, 2025, for the Coachella Valley. The proposed action was based on the EPA's evaluation of air quality monitoring data, and our determination that the State has satisfied the two statutory criteria for a one-year extension under CAA section 181(a)(5) and 40 CFR 51.907. For details regarding the EPA's reasons for proposing to grant the one-year extension, please see the March 17, 2025, proposal.
[^1] 90 FR 12239, March 17, 2025.
**II. Public Comments and the EPA's Responses**
The EPA's proposed action provided a 30-day public comment period. During this period, we received comments from Amber R, Air Law for All (ALFA), and Colin Williams. All the comments, which were received on April 16, 2025, are summarized and addressed below. The comments from Amber R and Colin Williams have been combined.
*Comment 1:* One commenter acknowledged the potential for wildfires to affect ozone levels but questioned their use to justify another extension. The commenter emphasized the need for bold action by the South Coast Air Quality Management District (SCAQMD) and CARB to “accelerate efforts to reduce ozone forming emissions.” Another commenter was concerned that the EPA was prolonging exposure to respiratory illnesses, such as emphysema and bronchitis. The commenter recommended immediate aggressive response to reduce emissions, improve air quality, more stringently enforce existing regulations, develop a more robust system to monitor air quality, and adopt cleaner technologies.
*Response 1:* As discussed in the proposal to grant the one-year extension of the attainment date, the EPA reviewed 2023 annual mean concentrations at each of the regulatory monitoring sites in the Coachella Valley. We determined that such data indicate that ozone concentrations were at or below 0.084 parts per million (ppm), [^2] which is one of two minimum criteria necessary to grant an extension.
[^2] The 1997 ozone standard was set at a level of 0.08 ppm, which is equivalent to 0.084 ppm using standard rounding conventions. For more information, see 73 FR 16436 (March 27, 2008).
Our determination relied on the exclusion of certain air quality monitoring data based on our December 10, 2024, concurrence on the State's exceptional events demonstration. As described in our proposal, 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 and granted the EPA with the authority to propose regulations to review and manage air quality monitoring data influenced by exceptional events. As stated in CAA section 319(b), an exceptional event is an event that “(1) affects air quality, (2) is not reasonably controllable or preventable, (3) is caused by human activity that is unlikely to recur at a particular location or was a natural event, and (4) is determined by the Administrator through a process established in regulations to be an exceptional event.” For EPA to concur on an exceptional event demonstration, the exclusion of data showing an exceedance or violation of the NAAQS must have regulatory significance. Here, the Highland, Rabbit, and Reche wildfires had regulatory significance to qualify the area for an attainment date extension, pursuant to 40 CFR 50.14(1)(i)(D). Furthermore, under the EPA's regulations implementing CAA section 319(b) for wildfires, the EPA is required to exclude exceptional events from wildfires “where a State demonstrates to the Administrator's satisfaction that emissions from wildfires caused a specific air pollution concentration in excess of one or more national ambient air quality standard at a particular air quality monitoring location.” [^3] Because we found that the State's demonstration satisfied the regulatory requirements and concurred on the demonstration, the excluded days were not considered in our evaluation of the air quality criteria for a one-year extension, as required by our regulations. [^4]
[^3] 40 CFR 50.14(b)(4).
[^4] The State's exceptional event demonstration is included in the docket for this action.
Despite the extension, the area will remain subject to Extreme classification requirements for the 1997 ozone NAAQS. The area is not relieved of any planning obligations under the CAA as a result of the extension. Within six months of the June 15, 2025 attainment date, the CAA and EPA's implementing regulations obligate the EPA to publish, in the *Federal Register* , a determination of whether the area has attained the 1997 ozone NAAQS. If the area has met the NAAQS, the EPA will publish a determination that the area attained by its attainment date. If the State does not demonstrate attainment with the 1997 ozone NAAQS based on the 2024 design value and is not eligible for a second one-year extension, the EPA will issue a finding of failure to attain and the State will become subject to additional CAA requirements to achieve attainment of the 1997 annual ozone NAAQS in the Coachella Valley. [^5] Furthermore, the nonattainment area remains subject to more stringent air quality standards under the 2008 and 2015 ozone NAAQS.
[^5] The EPA notes that the certified data in a design value report for the Palm Springs monitor, the only monitor in the Coachella Valley that did not attain the 1997 ozone NAAQS, indicates the monitor has attained the NAAQS based on the 2024 design value. Air Quality Systems, 2024 Design Value Report, U.S. EPA, dated May 7, 2025, has been added to the docket for the rulemaking.
Regarding air quality monitoring, the SCAQMD has established a monitoring network consistent with the EPA's requirements at 40 CFR part 58, which is documented in our review of the District's annual monitoring network plans and technical systems audits. The docket for the rulemaking contains the District's annual monitoring plans for 2023 and 2024, the EPA's approval letters, and the findings from the EPA's technical systems audit. More information on the nonattainment area's monitoring network can be found in section II.B.2 of the proposed rule (90 FR 12239, March 17, 2025).
*Comment 2.A:* Commenters assert that the EPA's proposal did not explain whether the EPA has previously granted any one-year extensions for the Coachella Valley nonattainment area pursuant to CAA section 181(a)(5). In a footnote, commenters argue that a plain language reading of CAA section 181(a)(5) indicates that the statutory limitation of two one-year extensions applies to any extension for any ozone standard for a nonattainment area. They claim that omitting additional information regarding other one-year extensions from the proposal constitutes inadequate notice. Moreover, commenters argue that proper notice requires a statement of the legal effects of the proposal, which includes an indication of how many one-year extensions the nonattainment area has remaining.
*Response 2.A:* The EPA disagrees with commenters that CAA section 181(a)(5) can be read to limit a nonattainment area to two cumulative one-year extensions for all ozone NAAQS. As a result, the EPA believes it provided adequate notice in the proposed approval.
First, the best reading of the statute does not suggest such a strong limitation of the extension authority. CAA section 181, under subpart 2 of part D of title I, was written for a single ozone standard, the 1979 1-hour ozone NAAQS. [^6] Likewise, the analogous provision under subpart 1, CAA section 172(a), governs classifications and attainment dates pertaining to a single NAAQS at a time. [^7] Subparts 3 and 4 also guide a state through the steps of classification and attainment dates for carbon monoxide and particulate matter nonattainment areas, respectively, for a single NAAQS at a time. [^8] With this context, it would be unreasonable to conclude that Congress intended the prohibition on the number of one-year extensions to apply to all NAAQS for a particular pollutant. This interpretation would lead to the undesirable outcome that a nonattainment area would not be able to avail itself of a one-year extension for a much more stringent ozone NAAQS decades in the future because they were granted two one-year extensions prior to attaining the 1979 1-hour ozone NAAQS.
[^6] Later ozone NAAQS have relied on subpart 2 to guide implementation. See 69 FR 23951 (April 30, 2004) (implementing the 8-hour ozone NAAQS in accordance with subpart 1 and subpart 2); see also 62 FR 38885 (July 18, 1997) (“These [Subpart 2] provisions do not lead to the conclusion that because Congress established them for the O <sub>3</sub> standard in effect at the time of the 1990 amendments, Congress meant that EPA could not revise that standard in order to appropriately protect public health.”).
[^7] CAA section 172(a)(2)(A) (“The attainment date for an area designated nonattainment with respect to a national primary ambient air quality standard. . .”).
[^8] Both subparts contain the same two one-year extension limitation as in subparts 1 and 2.
Indeed, in the general preamble to the 1990 CAA amendments, the EPA described situations where an ozone nonattainment area would “receive one or two extensions (under section 181(a)(5)) for the 1979 1-hour ozone NAAQS.” [^9] But at no point in the general preamble's discussion of CAA section 181(a)(5) does the EPA caution states or nonattainment areas that these extensions, if granted, would be the only two one-year extensions they could ever receive for any ozone NAAQS. Nor does the EPA acknowledge this sort of limitation in the agency's subsequent implementation of the 8-hour ozone NAAQS. Both the 2008 and 2015 ozone NAAQS implementation rules include their own unique provision referencing CAA section 181(a)(5), 40 CFR 51.1107 (2008 ozone NAAQS) and 40 CFR 51.1307 (2015 ozone NAAQS). Neither regulatory provision references a limitation on one-year extensions from previously granted extensions from other NAAQS (or from earlier classifications of the same NAAQS). [^10] Thus, the EPA's historical interpretation of CAA section 181(a)(5) also supports the EPA's conclusion in this final action.
[^9] 57 FR 13507 (April 16, 1992).
[^10] Under 40 CFR 51.1119, the provisions in 40 CFR part 51 subpart AA for the 2008 ozone NAAQS apply to the revoked 1997 ozone NAAQS.
Because CAA section 181(a)(5) applies to a specific NAAQS, our proposal adequately explains the history of attainment dates for the Coachella Valley nonattainment area for the purposes of providing adequate notice of the legal effects for a one-year extension of the attainment date for the 1997 ozone NAAQS. As described in our proposal, following initial classification as “Serious” nonattainment for the 1997 ozone NAAQS, the EPA set the Coachella Valley nonattainment area's attainment date as no later than June 15, 2013. [^11] Effective June 4, 2010, the EPA granted a reclassification request from Serious to “Severe-15” and set the attainment date as no later than June 15, 2019. [^12] The EPA again approved a reclassification request on July 10, 2019, to reclassify the nonattainment area from Severe-15 to Extreme and set the attainment date as June 15, 2024. [^13] The EPA's proposed approval of a one-year extension concerns the extension of the June 15, 2024 attainment date.
[^11] 69 FR 23858 (April 30, 2004).
[^12] 75 FR 24409 (May 5, 2010).
[^13] 84 FR 32841 (July 10, 2019).
Thus, as demonstrated in our proposal, the Coachella Valley nonattainment area has never requested and the EPA has never acted on a request from California for a one-year extension of the attainment date for the Coachella Valley nonattainment area for the 1997 ozone NAAQS. [^14] Upon finalizing this one-year extension, the Coachella Valley will be entitled to one additional one-year extension of the applicable attainment date for the 1997 ozone NAAQS, provided the nonattainment area meets the requirements of CAA section 181(a)(5). [^15]
[^14] For informational purposes, for the 2008 ozone NAAQS, the EPA designated and classified the Coachella Valley nonattainment area as Severe-15 and set the attainment date as no later than July, 20, 2027. 77 FR 30088 (May 21, 2012). Effective April 7, 2023, the EPA granted the Coachella Valley's voluntary reclassification request from Severe-15 to Extreme and set the attainment date as no later than July 20, 2032. 88 FR 14291 (March 8, 2023). For the 2015 ozone NAAQS, the EPA designated and classified the Coachella Valley nonattainment area as Severe and set the attainment date for no later than August 3, 2033. 83 FR 10376 (March 9, 2018). Thus, no one-year extensions have been granted for these NAAQS.
[^15] The EPA notes that, given the certified air quality levels in Coachella Valley from 2022 and 2023, a 2024 4th highest value that is below the NAAQS would put the 3-year design value below the standard, and thus, the area would demonstrate attainment with the 1997 ozone NAAQS. In other words, if the Coachella Valley satisfies the criteria for a second one-year extension, it will also be able to demonstrate attainment of the NAAQS, and an extension will be unnecessary.
*Comment 2.B:* Commenters argue that under CAA section 181(a)(5)(A), a state must demonstrate that it has complied with all requirements and commitments pertaining to the applicable implementation plan, which includes any Federal Implementation Plan (FIP) governing the nonattainment area in question. Commenters then argue that because South Coast is a delegated authority to implement EPA's federal prevention of significant deterioration (PSD) regulations, which constitute a FIP, the District is required to certify that it is complying with the EPA's PSD regulations.
The commenters note that the nonattainment New Source Review (NNSR) permit program applies to Coachella Valley, but they argue that sources outside the area will impact ozone levels within the nonattainment area, and therefore, PSD regulations “pertain to the area” within the meaning of CAA section 181(a)(5).
*Response 2.B:* The EPA disagrees with commenters that a determination of California's compliance with Federal PSD regulations is necessary for granting a one-year extension under CAA section 181(a)(5) for the Coachella Valley nonattainment area for the 1997 ozone NAAQS, given the area's status under that NAAQS as Extreme and the NNSR permitting requirements that are therefore applicable to that area.
Under the CAA, a PSD permitting program applies to areas designated as attainment/unclassifiable. [^16] As commenters acknowledge, the nonattainment area's NNSR permit program applies for sources of ozone precursors within the Coachella Valley because the area is subject to nonattainment area requirements for all ozone NAAQS, including the 1997 ozone NAAQS. Indeed, there are no PSD permits within the Coachella Valley nonattainment area for sources of ozone precursors. [^17]
[^16] See 89 FR 84286 (October 22, 2024) (The PSD “program sets forth procedures for the preconstruction review and permitting of new and modified stationary sources of air pollution located in areas meeting the National Ambient Air Quality Standards (NAAQS) (“attainment” areas) and areas for which there is insufficient information to classify an area as either attainment or nonattainment (“unclassifiable” areas).”); 40 CFR 52.21(a)(1) (“The provisions of this section are applicable to any State implementation plan which has been disapproved with respect to prevention of significant deterioration of air quality in any portion of any State where the existing air quality is better than the national ambient air quality standards.”).
[^17] Email dated May 5, 2025, from Sang-Mi Lee (SCAQMD) to Thomas Kelly (EPA), Subject: “PSD Permits in Coachella Valley?”.
The commenters appear to argue that because there may be PSD permitted sources outside of the Coachella Valley nonattainment area that impact ozone levels within the nonattainment area, PSD regulations would nonetheless apply as requirements “pertaining to the area” within the meaning of CAA section181(a)(5). The EPA does not believe there is any legal basis to this interpretation of the CAA, and the commenters do not cite to any authority to support their theory. The CAA section 181(a)(5)(A) requires that “the State has complied with all requirements and commitments pertaining to the area in the applicable implementation plan.” The better reading of that provision is that it is limited to whether a state is complying with a requirement or commitment that actually applies to the area, not a requirement or commitment that could theoretically have some unspecified impact on the area. With respect to permitting requirements, the Coachella Valley SIP includes requirements for the NNSR permitting program that is applicable for new and modified sources within Coachella Valley. [^18] Further, the commenter asserts with no support that sources outside the area “will impact” ozone levels within the area and thus the PSD requirements qualify as requirements “pertaining to” the area. The commenter does not provide any factual basis for how the construction or modification of sources under the PSD program, outside of the Coachella Valley area, will have any such impact on the air quality in the area. There is no legal or factual basis for the commenter's interpretation of CAA section 181(a)(5).
[^18] See “Coachella Valley Extreme Area Plan for the 1997 Ozone Standard,” p. 6-31.
*Comment 2.C:* Commenters argue that the EPA improperly ignored its discretion in granting the one-year extension. They argue that the EPA's proposal approached the statutory language as though it required the EPA to grant the extension, instead of the correct reading of the statutory language, which permits but does not require the EPA to grant the extension. They further argue that as a result, the EPA did not evaluate additional context regarding the nonattainment area, including the area's history of nonattainment, and its decision to grant the extension is therefore arbitrary and capricious.
*Response 2.C:* The EPA disagrees with commenters that it is improperly exercising its discretion in approving the one-year extension. The EPA does not dispute that CAA section 181(a)(5) grants the EPA the discretion to disapprove a state application for a one-year extension of the applicable attainment date, even if the area were to satisfy the two statutory requirements under CAA 181(a)(5). But the EPA disagrees with commenters' characterization of that discretion, which turns the EPA's authority from CAA section 181(a)(5) inside-out, as well as the notion that the EPA, in responding to commenters, is now advancing a post-hoc explanation of its proposal.
First, the CAA and the EPA's associated regulations regarding one-year extensions for ozone nonattainment areas provide a clear framework for states and the EPA to evaluate whether a state qualifies for a one-year extension. To grant an extension, the EPA must determine that (1) the State has complied with all requirements and commitments pertaining to the area in the applicable implementation plan; and (2) no more than one exceedance of the NAAQS level for ozone has occurred in the area in the year preceding the Extension Year. These are the elements Congress determined would indicate that an area is nearing attainment and that some flexibility may provide adequate time for the area to attain without requiring a new planning cycle. If the EPA determines that both criteria are satisfied, and the nonattainment area has not already been granted the two allowable one-year extensions for that NAAQS, the EPA may approve the one-year extension—the statute does not identify any other criteria the EPA must evaluate to do so.
Nonetheless, there are instances where the EPA may look beyond those two criteria and may even ultimately disapprove an application for a one-year extension on grounds not explicitly identified under the two statutory criteria. For example, the commenters point to guidance concerning procedures for processing bump-ups and extension requests for “Marginal” ozone nonattainment areas, including additional considerations for granting extensions to Marginal ozone nonattainment areas under CAA section 181(a)(5). [^19] But this guidance is illustrative of the reasons those considerations for Marginal ozone nonattainment areas are not applicable to the Coachella Valley nonattainment area for the 1997 ozone NAAQS, and thus, EPA's proposal adequately explained its rationale for approving the extension.
[^19] Commenters also cite to a recent example in Uinta Basin regarding a one-year extension of a Marginal ozone nonattainment area. The EPA is currently reconsidering our final action on that extension. But the EPA's rationale in this final action regarding guidance for Marginal ozone nonattainment areas would apply equally to distinguishing Coachella Valley with the unique circumstances in the Uinta Basin.
The EPA's guidance cited by commenters encourages that, given the “very tight timeframes to implement the new SIP requirements [if a Marginal area ultimately fails to attain], in addition to achieving the reductions to meet the new attainment date,” Marginal nonattainment areas applying for a one-year extension should start preparing for the potential that the area may be required to implement the next highest classification nonattainment area requirements. [^20] To do so, the EPA suggested the State submit with their extension application: (1) documentation that the State has planned or begun the necessary monitoring activities to develop information for the modeling analysis that will be required for the new classification; (2) documentation that the State has examined its legislative authority and regulatory procedures to determine whether or not it can quickly adopt and implement the emissions controls needed to meet the new attainment date; and/or (3) a plan to meet the SIP submittals and attainment date required by the higher classification. [^21] With this guidance, the EPA leaves open, but does not commit the agency to, the possibility that the agency may find a one-year extension for a Marginal nonattainment area inappropriate if the area does not appear prepared for a bump-up or is otherwise not nearing attainment.
[^20] Memorandum from D. Kent Berry, Acting Director, “Procedures for Processing Bump Ups and Extension Requests for Marginal Ozone Nonattainment Areas” (February 3, 1994).
[^21] Id.
Notably, Marginal ozone nonattainment areas are not required to prepare reasonable further progress demonstrations, attainment demonstrations, or implement “reasonable available control measures” as a part of their SIP planning process. The lack of these planning obligations—and associated modeling—for Marginal ozone nonattainment areas makes it all the more important that the State has the planning capacity in place if they do not have an attaining design value by the Marginal attainment date, even if they qualify for the criteria for a one-year extension. Because higher ozone nonattainment classifications, like Extreme nonattainment, are required to model attainment and implement stricter control measures, they have already undergone significant nonattainment planning and much of the information lacking from a Marginal nonattainment area's one-year extension request is already available for the EPA to fully evaluate the nonattainment area's control measure strategy for higher classifications or the likelihood that a one-year extension will lead to attainment by the extended attainment date.
Effective July 12, 2024, the EPA approved portions of the Coachella Valley's Extreme nonattainment SIP for the 1997 ozone NAAQS, specifically the area's RACM demonstration and attainment demonstration as well as other CAA requirements. [^22] Our final action approved a determination that “the District's control strategy [is] acceptable for purposes of attaining the 1997 ozone standards in the Coachella Valley” and that the attainment demonstration “shows the area attaining the 1997 ozone standards by the outermost statutory attainment date of June 15, 2024.” [^23] With this context, the EPA's proposed approval of a one-year extension for the Coachella Valley nonattainment area evaluated the state's progress towards implementing the control measures from the applicable SIP as well as the relevant air quality data for the nonattainment area. Based on our evaluation, we found that the area was complying with its SIP's implementation schedule and the area's air quality is nearing attainment of the NAAQS, with the area's air quality below the standard in 2023. [^24] We therefore determined that the application was adequate to grant the one-year extension.
[^22] 89 FR 26817 (April 16, 2024).
[^23] 89 FR 26817 (June 15, 2024); 89 FR 49815 (June 12, 2024).
[^24] The 2023 design value for Coachella Valley is 0.085 ppm, based on data from 2021 to 2023, which is down from 0.108 ppm in 2003. See Coachella Valley Extreme Area Plan for the 1997 Ozone Standard, p. 5-2. The EPA also notes that the certified data in a preliminary design value report for the Palm Springs monitor, the only monitor in the Coachella Valley that did not attain the 1997 ozone NAAQS, indicates the monitor has attained the NAAQS based on the 2024 design value. Air Quality Systems, Preliminary Design Value Report, U.S. EPA, dated May 7, 2025, has been added to the docket for the rulemaking.
Commenters do not point to any specific characteristics of the Coachella Valley, the nonattainment area's control strategy, or its recent air quality that would weigh in favor of the EPA exercising its discretion to reject a nonattainment area's application that satisfies the statutory criteria. Nor do they identify any reason why rejecting the extension request and finding the area failed to attain would expedite attainment of the 1997 ozone NAAQS. The only specific detail commenters identify regarding the nonattainment area is that it has not yet attained the 1997 ozone NAAQS. The EPA acknowledges that the Coachella Valley nonattainment area has historically struggled to attain this NAAQS and did not have an attaining design value by the applicable attainment date. But absent any other supporting justifications for rejecting California's application, these facts alone are not factors Congress instructed us to consider. [^25] The very purpose of a one-year extension is to provide flexibility for areas that are not yet in attainment. Thus, based on our evaluation of air quality monitoring data and the extension request submitted by the California, we are finalizing the one-year extension as proposed.
[^25] See *Motor Vehicle Mfrs. Ass'n of the U.S., Inc.* v. *State Farm Auto. Ins. Co.,* 463 U.S. 29, 48 (1983).
**III. The EPA's Action**
In response to the request from the State of California on October 11, 2024, the EPA is granting a one-year extension to the applicable attainment date for the 1997 ozone NAAQS for Coachella Valley. Additionally, the EPA is taking final action on the exceptional events request submitted by CARB on October 11, 2024, and concurred with by EPA on December 10, 2024. This final action extends the applicable attainment date from June 15, 2024, to June 15, 2025, for this nonattainment area. This decision is based on the State's compliance with the requirements in the applicable SIP for the area and on the 2023 ozone monitoring data from sites in the Coachella Valley.
**IV. Statutory and Executive Order Reviews**
This action provides a one-year extension of the Coachella Valley attainment date for the 1997 ozone NAAQS from June 15, 2024, to June 15, 2025, and imposes no additional requirements. For that reason, this action:
• Is not a significant regulatory action subject to review by the Office of Management and Budget under Executive Order 12866 (58 FR 51735, October 4, 1993);
• Is not subject to Executive Order 14192 (90 FR 9065, February 6, 2025) because SIP actions are exempt from review under Executive Order 12866;
• 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 in Executive Order 13132 (64 FR 43255, August 10, 1999);
• Is not subject to Executive Order 13045 (62 FR 19885, April 23, 1997) because it approves a state program;
• Is not a significant regulatory action subject to Executive Order 13211 (66 FR 28355, May 22, 2001); and
• 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 Clean Air Act.
In addition, 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. In those areas of Indian country, the rule does not have Tribal implications and will not impose substantial direct costs on Tribal governments or preempt Tribal law as specified by Executive Order 13175 (65 FR 67249, November 9, 2000).
This action is subject to the Congressional Review Act, and the EPA will submit a rule report to each House of the Congress and to the Comptroller General of the United States. This action is not a “major rule” as defined by 5 U.S.C. 804(2).
Under section 307(b)(1) of the Clean Air Act, petitions for judicial review of this action must be filed in the United States Court of Appeals for the appropriate circuit by November 4, 2025. Filing a petition for reconsideration by the Administrator of this final rule does not affect the finality of this action for the purposes of judicial review nor does it extend the time within which a petition for judicial review may be filed and shall not postpone the effectiveness of such rule or action. This action may not be challenged later in proceedings to enforce its requirements. (See section 307(b)(2)).
**List of Subjects in 40 CFR Part 81**
Environmental protection, Air pollution control, Nitrogen oxides, Ozone, Reporting and recordkeeping requirements, Volatile organic compounds.
Dated: August 25, 2025.
Joshua F.W. Cook,
Regional Administrator, Region IX.
For the reasons stated in the preamble, the EPA amends part 81, chapter I, title 40 of the Code of Federal Regulations as follows:
**PART 81—DESIGNATION OF AREAS FOR AIR QUALITY PLANNING PURPOSES**
**40 CFR Part 81**
1. The authority citation for part 81 continues to read as follows:
**Authority:**
42 U.S.C. 7401 *et seq.*
**Subpart C—Section 107 Attainment Status Designations California**
**40 CFR Part 81**
2. Section 81.305 is amended in the table for “California 1997 8-Hour Ozone NAAQS [Primary and Secondary]” by:
a. Revising the entry for “Riverside Co. (Coachella Valley), CA”;
b. Adding footnote “h.”; and
c. Revising footnote “2”
The revisions and additions read as follows:
§ 81.305
| Designated area | Designation | Date | Type | Category/classification | Date | Type |
| --- | --- | --- | --- | --- | --- | --- |
| | | | | | | |
| * * * * * * * | | | | | | |
| Riverside Co. (Coachella Valley), CA | | | | | | |
| Riverside County (part) | | Nonattainment | 6/12/19 | Subpart 2/Extreme. | | |
| That portion of Riverside County which lies to the east of a line described as follows: Beginning at the Riverside-San Diego County boundary and running north along the range line common to Range 4 East and Range 3 East, San Bernardino Base and Meridian; then east along the Township line common to Township 8 South and Township 7 South; then north along the range line common to Range 5 East and Range 4 East; then west along the Township line common to Township 6 South and Township 7 South to the southwest corner of Section 34, Township 6 South, Range 4 East; then north along the west boundaries of Sections 34, 27, 22, 15, 10, and 3, Township 6 South, Range 4 East; then west along the Township line common to Township 5 South and Township 6 South; then north along the range line common to Range 4 East and Range 3 East; then west along the south boundaries of Sections 13, 14, 15, 16, 17, and 18, Township 5 South, Range 3 East; then north along the range line common to Range 2 East and Range 3 East; to the Riverside-San Bernardino County line. And that portion of Riverside County which lies to the west of a line described as follows: | | | | | | |
| That segment of the southwestern boundary line of Hydrologic Unit Number 18100100 within Riverside County, further described as follows: Beginning at the Riverside-Imperial County boundary and running north along the range line common to Range 17 East and Range 16 East, San Bernardino Base and Meridian; then northwest along the ridge line of the Chuckwalla Mountains, through Township 8 South, Range 16 East and Township 7 South, Range 16 East, until the Black Butte Mountain, elevation 4504′; then west and northwest along the ridge line to the southwest corner of Township 5 South, Range 14 East; then north along the range line common to Range 14 East and Range 13 East; then west and northwest along the ridge line to Monument Mountain, elevation 4834′; then southwest and then northwest along the ridge line of the Little San Bernardino Mountains to Quail Mountain, elev. 5814′; then northwest along the ridge line to the Riverside-San Bernardino County line. | | | | | | |
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