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Ground-level Ozone Pollution

1997 Ozone National Ambient Air Quality Standards (NAAQS) Nonattainment Actions

Implementation of the Revoked 1997 8-hour Ozone National Ambient Air Quality Standards; Updating Federal Regulations to Show Areas that Attained by the Attainment Date

August 31, 2020 - EPA confirmed for the public and state air agencies that nine areas attained the1997 ozone National Ambient Air Quality Standards (NAAQS) by their respective attainment dates.  This action recognizes the effort these areas took to address ozone air quality and ensures that they will not be subject to consequences for not attaining the standards as required.  The areas are:

  1. Buffalo-Niagara Falls, New York;
  2. Jamestown, New York;
  3. Jefferson County, New York;
  4. Poughkeepsie, New York;
  5. Shoreline Sheboygan County, Wisconsin;
  6. Inland Sheboygan County, Wisconsin;
  7. Denver-Boulder-Greeley-Ft. Collins-Loveland, Colorado;
  8. San Francisco Bay Area, California; and,
  9. Ventura County, California.

Read the direct final rule, parallel proposal and summary fact sheet.

December 3, 2020 - Withdrawal of Direct Final Rule - EPA is withdrawing its direct final rule published on October 9, 2020, intended to codify in 40 CFR part 52 and confirm for the public and state air agencies that nine areas in four states attained the revoked 1997 ozone National Ambient Air Quality Standards by their respective attainment dates.  EPA will consider an adverse comment received on the parallel proposal published on the same day, and will include a written response to the comment in a subsequent final rule.  Read the withdrawal notice.

Resource Document for 1997 Ozone NAAQS Areas: Supporting Information for States Developing  Maintenance Plans

November 20,  2018 – EPA is providing a Resource Document and supporting technical information to assist states in developing maintenance plans for certain areas that were designated as nonattainment or redesignated to maintenance for the 1997 Ozone NAAQS prior to its revocation. The Resource Document also discusses the option of developing a “limited maintenance plan” for certain areas.

Implementing the 1997 8-hour Ozone National Ambient Air Quality Standards
April 27, 2012 - This final action revises the 2004 rule that specified the first phase of requirements that state, tribal and local air pollution control agencies would follow to meet the 1997 8-hour Ozone National Ambient Air Quality Standards. As a result of this action, the Clean Air Act classifications for 16 areas of the U.S. will be revised.

EPA proposes revisions to the reasonable further progress requirements for the 1997 8-hour ozone national ambient air quality standard.
December 15, 2010 - EPA is proposing to revise an earlier interpretation of its rule regarding requirements for Reasonable Further Progress (RFP) State Implementation Plans, and is also seeking comment on retaining the existing RFP approach.

EPA Issues Guidance for Fee Collection Programs - 1997 1-hour Ozone Standard
January 5, 2010 - EPA issued a guidance memorandum to help states develop fee collection programs for the 1-hour standard.

EPA Completes Revisions to 1997 8-Hour Ozone Implementation Phase 2 Rule to Address Vacatur and Remand of Reasonable Further Progress Credits
August 5, 2009 - This final rule will allow states to take credit for reductions of Volatile Organic Compound and nitrogen oxides emissions outside of a nonattainment area if the state can demonstrate that those reductions would help the nonattainment area meet its reasonable further progress goals.