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Area Designations for 1997 Ground-level Ozone Standards

Regulatory Actions

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This page contains a chronological listing of all regulatory actions related to the 1997 8-hour ozone standard.

Final Notice of Reconsideration -- Aspects of Phase 2 Implementation Rule

EPA's response to questions regarding the impacts of a recent Court Decision to vacate the Phase 1 Ozone Implementation Rule.

Supplemental Proposed Rulemaking on 8-Hour Ozone Redesignations for Various Areas in Michigan, Ohio and West Virginia

Proposed Notice of Reconsideration -- Aspects of Phase 2 Implementation Rule

8-Hour Ozone Flex Program Announced

Proposed Notice of Reconsideration -- Overwhelming Transport Classification

EPA's Final Implementation Rule - Phase 2

Notice Revoking the 1-hour Standard in Most of the Nation

Ozone Clean Air Progress Will Continue

Bump-Down Requests

EPA's Final Implementation Rule-Phase I

EPA's Final Nonattainment Designations for 8-Hour Ozone




Final Notice of Reconsideration -- Aspects of Phase 2 Implementation Rule

May 31, 2007 - EPA completed reconsideration on is requesting public comment on several issues associated the ozone implementation rule requirements and their interaction with the Clean Air Interstate Rule and the New Source Review permitting program.

Notice of Reconsideration (PDF) (90 pp, 267KB)
Fact Sheet (PDF) (2 pp, 25KB)


EPA's response to questions regarding the impacts of a recent Court Decision to vacate the Phase 1 Ozone Implementation Rule.

March 19, 2007 - EPA's Acting Assistant Administrator, William L. Wehrum, signed a memorandum to be sent to EPA Regional Administrators. This memo is written in response to questions regarding the impacts of a recent Court Decision to vacate the Phase 1 Ozone Implementation Rule.

Memorandum (PDF) (3 pp, 135KB)


Supplemental Proposed Rulemaking on 8-Hour Ozone Redesignations for Various Areas in Michigan, Ohio and West Virginia

March 16, 2007 - In this supplemental proposal, EPA is requesting comment on its belief that the Agency may move forward to finalize proposed redesignations to attainment for ozone nonattainment areas in Michigan, Ohio and West Virginia.

Supplemental Proposal (PDF) (33 pp, 153KB)
Fact Sheet (PDF) (3 pp, 88KB)


Proposed Notice of Reconsideration -- Aspects of Phase 2 Implementation Rule

December 11, 2006 - EPA is requesting public comment on several issues associated the ozone implementation rule requirements and their interaction with the Clean Air Interstate Rule and the New Source Review permitting program.

Notice of Reconsideration (PDF) (55 pp, 140 KB)
Fact Sheet (PDF) (2 pp, 22KB)


8-Hour Ozone Flex Program Announced

May 18, 2006 - The 8-Hour Ozone Flex program is a voluntary agreement between the Environmental Protection Agency (EPA), State, Tribal, and local communities to encourage 8-hour ozone attainment areas nationwide to reduce ozone emissions so they can continue to meet the National Ambient Air Quality Standard (NAAQS) for ozone. This program will support and reward innovative, voluntary, local strategies to reduce ground-level ozone, thereby improving air quality and helping areas maintain attainment.

Memorandum (PDF) (2 pp, 85KB)
Guidance (PDF) (19 pp, 1.1MB)


Proposed Notice of Reconsideration -- Overwhelming Transport Classification

EPA is requesting public comment on several issues associated with the overwhelming transport classification available to certain areas designated "nonattainment" because they do not meet EPA's 8-hour ozone national ambient air quality standard.

Notice of Reconsideration (PDF) (46 pp, 167KB)
Fact Sheet (PDF) (4 pp, 126KB)


EPA's Final Implementation Rule - Phase 2

November 9, 2005 - EPA issued a final rule that will take the next steps to protect the American public from ground-level ozone pollution. This rule, often called the Phase 2 Ozone Rule, outlines the remaining elements of the program to implement the 8-hour ground-level ozone National Ambient Air Quality Standard that EPA established in July 1997. State, tribal and local government will rely upon these requirements as they develop their plans showing how they will attain or maintain the 8-hour ozone standard.

Final rule (PDF) (94pp, 613k) - Federal Register - November 29, 2005
Fact sheet (PDF) (3 pp, 70KB)
Fact sheet (print version)


Notice Revoking the 1-hour Standard in Most of the Nation

August 3, 2005 - EPA identified ozone areas for which the 1-hour standard has been revoked and issued technical corrections to the Phase 1 Rule.

Final Rule (PDF) (9 pp, 82KB)


Ozone Clean Air Progress Will Continue

July 26, 2005 - EPA identified the boundaries, designations, and classifications for areas under the 1-hour ozone standard that were in place as of June 15, 2004.

Final rule
Final rule in FR format (PDF) (9 pp, 84KB)
Fact sheet


Bump-Down Requests

On September 15, 2004, EPA reclassified nine of the identified 8-hour ozone nonattainment areas from moderate to the next lower classification-marginal. Follow the links below to read:

Bump-down request documents
Fact sheet about the change
Part 81 Revision (PDF) (15pp, 116KB)


EPA's Final Implementation Rule-Phase I

On June 15, 2004, EPA issued the final rule to implement the 8-hour Ozone National Ambient Air Quality Standard-Phase I. The phase I final rule sets forth the classification scheme for nonattainment areas and requires States' continued obligations with respect to existing 1-hour ozone requirements.

Final notice of reconsideration 05/20/2005
Final implementation rule (PDF) (279 pp, 517KB)
Final implementation rule fact sheet


EPA's Final Nonattainment Designations for 8-Hour Ozone

On April 15, 2004 EPA designated as "nonattainment" areas throughout the country that exceeded the health-based standards for 8-hour ozone. Follow the links below to read:

Fact sheet about the designations
Final designations rule:
  Preamble (PDF) (97 pp, 263KB)
  Part 81 (PDF) (52 pp, 131KB)
Table showing final designations
Frequent Questions
Press release
Map of nonattainment areas
Sample nonattainment requirements

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