EPA's Guidance for Implementation of the 1-Hour Ozone and Pre-Existing Particulate Matter Standards

Note: EPA no longer updates this information, but it may be useful as a reference or resource.

December 29, 1997

FACT SHEET

EPA'S GUIDANCE FOR IMPLEMENTATION OF THE 1-HOUR OZONE AND PRE-EXISTING PARTICULATE MATTER NATIONAL AMBIENT AIR QUALITY STANDARDS

Today's Action...

Today the Environmental Protection Agency is issuing guidance for States to use in implementing the Clean Air Act requirements for ground-level ozone and particulate matter during the transition time between implementation of the old and new air quality standards.
This guidance is intended to ensure that States maintain the momentum of existing control programs for ozone and particulate matter during the time when they are preparing their plans to implement the new standards.
This guidance applies to all areas now subject to EPA's 1-hour standard and the pre-existing particulate matter standards and provides additional flexibility to States to achieve these standards.
EPA will implement the concepts discussed in this guidance through subsequent guidance and rulemaking actions, as appropriate. Such rulemaking actions include approving or disapproving State implementation plan submittals.
In a related matter, EPA is releasing a list of all of the counties for which the 1-hour ozone standard has been revoked. The new 8-hour standard remains in effect for these counties. EPA will formally "designate" areas as attainment or nonattainment for the 8-hour standard in the year 2000.

Background

On July 17, 1997, following a lengthy scientific review process, the EPA revised the national ambient air quality standards for ground-level ozone and particulate matter.
Specifically, the EPA is phasing out and replacing the previous 1-hour ozone standard with a new 8-hour standard to protect against longer exposure periods. In addition, the EPA revised the primary and secondary particulate matter standard by establishing annual and 24-hour standards for smaller or "fine" particles (particles 2.5 micrometers in diameter or smaller) and by changing the form of the existing 24-hour particulate matter standard (for particles 10 micrometers in diameter or smaller).
EPA will "designate" areas as nonattainment for the new 8-hour ozone standard in the year 2000, based on the most recently available 3 years of air quality data at that time (e.g., 1997-1999). EPA will not designate areas as nonattainment for the revised particulate matter standard until 3 years of monitoring data in the area for that pollutant are available. Since implementation of these new standards is still several years away, the EPA has issued this guidance to maintain the momentum of existing State control programs.
The EPA is also preparing guidance and regulations on the implementation of these new standards and will issue these over the next year.
This guidance reflects President Clinton's July 16, 1997 directive to Administrator Browner which laid out a common-sense implementation strategy for the new standards as well as interim implementation of the 1-hour ozone and pre-existing particulate matter standards.

Key Elements of the Guidance...

The goal of this guidance is to ensure that essential programs required under the Clean Air Act for implementing the existing air quality standards are continued where it is appropriate to do so. Retaining these implementation provisions is expected to help areas transition to attainment planning for the new standards while avoiding "backsliding" to degraded air quality.
This guidance identifies: (1) parts of the Clean Air Act governing implementation of the 1-hour ozone and pre-existing particulate matter standards that continue to be applicable, (2) the process for revoking applicability of the 1-hour ozone and pre-existing particulate matter standards, and (3) the details of specific Clean Air Act requirements for continued progress in reducing emissions.
Specifically, the provisions of the Clean Air Act that govern implementation of the 1-hour ozone standard will continue to apply to all areas now subject to that standard until EPA makes a determination that the area's air quality meets the 1-hour standard. At that time, EPA will revoke the 1-hour standard for that area. Similarly, the Clean Air Act guidance for implementation of the pre-existing particulate matter standards will continue to apply in areas that do not meet this standard for an interim period until EPA revokes the pre-existing particulate matter standard in those areas.
The guidance provides for revocation of the existing standards for areas with clean air quality data if certain requirements are met. Even though the 1-hour ozone and pre-existing particulate matter standards would no longer apply once revoked, the new 8-hour ozone standard and the new particulate matter standards would apply. In the interim until EPA formally designates areas as nonattainment for the new ozone and particulate matter standards, areas would have to continue to implement the programs that lead to their attaining these standards. Today's guidance also allows for revisions of current attainment plan elements, as appropriate, to reflect the transition from the old standards to the new standards.
The guidance also provides States with additional flexibility to satisfy control programs for ozone mandated by the Clean Air Act. Specifically, the guidance will generally allow credit for emission reductions outside existing nonattainment areas to satisfy the post-1996 rate-of-progress requirements mandated by the Clean Air Act (e.g., 100 km outside the area for VOC emission reductions, and 200 km outside the area for NOx reductions and beyond in certain cases).

For Further Information

Interested parties can download this guidance from EPA's web site on the Internet under [recently signed rules] at the following address: (https://www.epa.gov/ttn/oarpg/rules.html). For further information about the guidance relating to implementation of the 1-hour ozone standard, contact Ms. Sharon Reinders of EPA's Office of Air Quality Planning and Standards at (919) 541-5284. For further information about the guidance relating to implementation of the existing particulate matter standard, contact Ms. Robin Dunkins of EPA's Office of Air Quality Planning and Standards at (919) 541-5335.
EPA's Office of Air and Radiation's homepage on the Internet contains a wide range of information on the ozone and particulate matter standards, as well as many other air pollution programs and issues. The Office of Air and Radiation's home page address is: (https://www.epa.gov/oar/).

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