SUPPLEMENTARY INFORMATION:

Throughout this document, wherever “we,” “us” or “our” are used, it is intended to refer to the EPA.

Table of Contents

I. Background and Purpose

II. EPA Clean Data Policy and Clean Data Determinations

III. Analysis of Air Quality Data

IV. Proposed Action

V. Statutory and Executive Order Reviews

( printed page 6689)

I. Background and Purpose

On October 26, 2015 (80 FR 65291), EPA promulgated a revised primary and secondary NAAQS for ozone to provide requisite increased protection of public health and welfare, respectively. In that action, EPA strengthened both standards from 0.075 parts per million (ppm) to 0.070 ppm, and retained the indicator (O₃), averaging time (8-hour) and form (annual fourth-highest daily maximum, averaged over three years) of the existing standards. Effective August 3, 2018 (83 FR 25776), EPA designated 52 areas throughout the country as nonattainment for the 2015 ozone NAAQS, including the Washington Area,^[1] which was classified as a Marginal nonattainment area. This designation was based on certified air quality monitoring data from calendar years 2014 to 2016. In that action, EPA established the attainment date for Marginal nonattainment areas as three years from the effective date of the final designations. Thus, the attainment date for Marginal nonattainment areas for the 2015 ozone NAAQS was August 3, 2021.^[2]

On April 13, 2022 (87 FR 21842), EPA proposed to determine that 24 Marginal areas, including the Washington Area, failed to attain the 2015 ozone NAAQS by their applicable attainment date and the areas were therefore going to be reclassified by operation of law as Moderate nonattainment upon the effective date of the final reclassification notice. On October 7, 2022 (87 FR 60897), EPA published the final action in the Federal Register stating that 22 Marginal areas or portions of areas failed to attain the standard by the applicable attainment date, including the Washington Area. In that action, EPA reclassified the Washington Area as Moderate nonattainment for the 2015 ozone NAAQS because it failed to attain the standard by the attainment date of August 3, 2021. This designation was based on quality-assured, quality-controlled, and certified ozone air quality monitoring data from calendar years 2018 to 2020. More recent air quality data from 2019 to 2021 indicates that the Washington Area is now attaining the 2015 ozone standard—the basis for EPA's proposed CDD.

II. EPA Clean Data Policy and Clean Data Determinations

Following enactment of the Clean Air Act (CAA) Amendments of 1990, EPA discussed its interpretation of the requirements for implementing the NAAQS in the “General Preamble for the Implementation of title I of the CAA Amendments of 1990” (General Preamble).^[3] In 1995, based on the interpretation of CAA sections 171, 172, and 182 in the General Preamble, EPA set forth what has become known as its “Clean Data Policy” for the 1-hour ozone NAAQS.^[4] Under the Clean Data Policy, for a nonattainment area that can demonstrate attainment of the standard before implementing CAA nonattainment measures, EPA interprets the requirements of the CAA that are specifically designed to help an area achieve attainment, including attainment demonstrations, implementation of reasonably available control measures (RACM), including reasonably available control technology (RACT), reasonable further progress (RFP) demonstrations, emissions limitations and control measures as necessary to provide for attainment, and contingency measures, to be suspended for so long as air quality continues to meet the standard.^[5]

EPA may issue a CDD under our Clean Data Policy when a nonattainment area is attaining the 2015 ozone NAAQS based on the most recent available data. EPA will determine whether the area has attained the 2015 ozone NAAQS based on available information, including air quality monitoring data for the affected area. If the CDD is made final, then certain attainment plan requirements for the area are suspended for so long as the area continues to attain the NAAQS.

Furthermore, the suspension of the obligation to submit an attainment plan is only appropriate where the area remains in attainment of the NAAQS. A CDD under the Clean Data Policy does not serve to alter the area's nonattainment designation. CDDs are not redesignations to attainment. For EPA to redesignate an area to attainment the state must submit, and EPA must approve, a redesignation request for the area that meets the requirements of CAA section 107(d)(3).

III. Analysis of Air Quality Data

EPA has reviewed the ambient air monitoring data for ozone, consistent with the requirements contained in 40 Code of Federal Regulations (CFR) part 50 and recorded in EPA's AQS database for the Washington Area from 2019 through 2022. On the basis of that review, EPA has concluded that this Area attained the 2015 ozone NAAQS at the end of the 2021 ozone season, based on certified 2019 to 2021 ozone data. In addition, preliminary ozone data for 2022 that are available in AQS, but not yet certified, is consistent with continued attainment of the 2015 ozone NAAQS.

Under EPA regulations, the 2015 ozone NAAQS is attained when the 3-year average of the annual fourth-highest daily maximum 8-hour average ozone concentrations at an ozone monitor is less than or equal to 0.070 ppm.^[6] This 3-year average is referred to as the design value (DV). When calculating the DV, digits to the right of the third decimal place are truncated.^[7] When the DV is less than or equal to 0.070 ppm at each monitor within the area, then the area is meeting the NAAQS. In addition, the 2015 ozone DVs are based solely on ozone season data.^[8] Ozone season is defined for each state or portion of a state.^[9] The ozone season for DC, MD and VA runs from March 1st to October 31st each year.^[10] There is also a data completeness requirement that is met when the average percentage of days with valid ambient monitoring data is greater than 90%, and no single year has less than 75% data completeness as determined in Appendix I of 40 CFR part 50. The Washington Area has complete data for the years 2018 to 2021, as shown in Table 1 in this document.

( printed page 6690)

Table 2 in this document shows the fourth-highest maximum 8-hour average ozone concentrations for the Washington Area monitors for the years 2018 to 2022. Table 3 in this document shows the ozone design values for these same monitors based on the following 3-year periods: 2018-2020, 2019-2021 and 2020-2022.

( printed page 6691)

EPA's review of these data indicate that the Washington Area met the attainment standard in 2019-2021 and the preliminary data from 2022 indicates that the DV for the period of 2020-2022 is consistent with continued attainment of the 2015 ozone NAAQS.

IV. Proposed Action

EPA is proposing to determine that the Washington Moderate ozone nonattainment area has attained the 2015 NAAQS for ozone. This determination is based upon certified ambient air monitoring data that show the area has monitored attainment of the 2015 ozone NAAQS based on 2019 to 2021 data. In addition, preliminary ^[11] ozone data for 2022 that are available in EPA's AQS database, but not yet certified, is consistent with continued attainment of the 2015 ozone NAAQS. As provided in 40 CFR 51.1318, if EPA finalizes this CDD, it would suspend the requirements for such area to submit attainment demonstrations, associated RACM, including RACT, RFP plans, and contingency measures under CAA section 172(c)(9), and any other planning State Implementation Plan (SIP) revision related to attainment of the 2015 ozone NAAQS for this Area, for so long as the area continues to attain the standard. EPA is soliciting public comments on the issues discussed in this document or on other relevant matters. These comments will be considered before taking final action. Interested parties may participate in the Federal rulemaking procedure by submitting written comments to this proposed rule by following the instructions listed in the ADDRESSES sections of this Federal Register .

V. Statutory and Executive Order Reviews

This rulemaking action makes a clean data determination for attainment of the 2015 ozone NAAQS based on air quality and does not impose additional requirements. For that reason, this clean data determination:

• 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, this proposed clean data determination for the Washington Area for the 2015 ozone NAAQS does not have tribal implications as specified by Executive Order 13175 (65 FR 67249, November 9, 2000), because the SIP is not approved to apply in Indian country located in the multi-state area, and EPA notes that it will not impose substantial direct costs on tribal governments or preempt tribal law.

88 FR 6688