SUPPLEMENTARY INFORMATION:

I. General Information

A. How can I get copies of this document and related information?

1. Docket. EPA has established a docket for this action under Docket ID No. EPA-HQ-OAR-2018-0279. A separate docket established for the Integrated Science Assessment being prepared for this action (EPA-HQ-ORD-2018-0274) is also incorporated into the rulemaking docket for this review. Publicly available docket materials are available electronically through www.regulations.gov or may be viewed at the Air and Radiation Docket and Information Center, EPA/DC, EPA West, Room 3334, 1301 Constitution Ave. NW, Washington, DC. The Public Reading Room is open from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal holidays. The telephone number for the Public Reading Room is (202) 566-1744, and the telephone number for the Air and Radiation Docket and Information Center is (202) 566-1742.

2. The document announced today and related information will be available via the internet on the EPA's website at https://www.epa.gov/​naaqs/​ozone-o3-air-quality-standards. The document announced today will be accessible under “Planning Documents” from the current review.

II. Information Specific to This Document

Two sections of the Clean Air Act (CAA or the Act) govern the establishment and revision of the NAAQS. Section 108 directs the Administrator to identify and list certain air pollutants and then issue “air quality criteria” for those pollutants. The air quality criteria are to “accurately reflect the latest scientific knowledge useful in indicating the kind and extent of all identifiable effects on public health or welfare which may be expected from the presence of such pollutant in the ambient air. . .” (CAA ( printed page 43807) section 108(a)(2)). Under section 109 of the Act, the EPA is then to establish primary (health-based) and secondary (welfare-based) NAAQS for each pollutant for which the EPA has issued air quality criteria. Section 109(d)(1) of the Act requires periodic review and, if appropriate, revision of existing air quality criteria. Revised air quality criteria are to reflect advances in scientific knowledge on the effects of the pollutant on public health and welfare. Under the same provision, the EPA is also to periodically review and, if appropriate, revise the NAAQS, based on the revised air quality criteria.

The Act additionally requires appointment of an independent scientific review committee that is to periodically review the existing air quality criteria and NAAQS and to recommend any new standards and revisions of existing criteria and standards as may be appropriate (CAA section 109(d)(2)(A)-(B)). Since the early 1980s, the requirement for an independent scientific review committee has been fulfilled by the Clean Air Scientific Advisory Committee (CASAC).

Presently the EPA is reviewing the air quality criteria and NAAQS for photochemical oxidants and O₃ .^[1] The document announced in this notice has been developed as part of the planning phase for the review. In this phase, a draft IRP was prepared jointly by the EPA's National Center for Environmental Assessment, within the Office of Research and Development, and the Office of Air Quality Planning and Standards, within the Office of Air and Radiation. The draft IRP was the subject of a consultation with CASAC on November 29, 2018 and was available for public comment (83 FR 55163, November 2, 2018; 83 FR 55528, November 6, 2018). The document announced today has been prepared after consideration of CASAC and public comments. This IRP presents EPA's current plans for the schedule for the entire review, the process for conducting the review, and the key policy-relevant science issues that will guide the review. This document does not represent and should not be construed to represent any final EPA policy, viewpoint, or determination.