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Early Action Compacts - 1997 Ozone Standard

Fact Sheet - Final Extension to Defer Clean Air Act Requirements for 8-hour Ozone National Ambient Air Quality Standards for the Denver Early Action Compact

Information provided for informational purposes onlyNote: EPA no longer updates this information, but it may be useful as a reference or resource.


  • On September 13, 2007, the U.S. Environmental Protection Agency finalized deferral of Clean Air Act requirements to reduce ozone pollution for the Denver Early Action Compact (EAC) area from September 14, 2007 to November 20, 2007.  Communities with Early Action Compacts are reducing smog one to two years sooner than required by the Clean Air Act.
  • The deferral serves two purposes, (1) provides time for EPA to review the latest air quality data for the Denver area; and (2) provides time to publish and take comment on a settlement agreement reached between EPA and a Denver environmental group after it challenged EPA’s previous deferral for the Denver area.

Air Quality Data Review

  • The deferral provides time for EPA to evaluate Denver’s ozone data for 2005, 2006 and the first three quarters of 2007, to see if the region remains eligible to stay in the EAC program.  
  • To date, Colorado has met their milestones for submitting progress reports for the Denver area.  The progress reports describe actions taken to reduce smog in the Denver area so this community will attain the 8-hour ozone NAAQS by November 20, 2007. Colorado has also approved legislation to reduce ozone-forming pollutants from the oil and gas industry.

Settlement Publication and Comment Request

  • A Colorado environmental group challenged the EPA’s action to extend Denver’s deferral until July 1, 2007. EPA and the environmental group have agreed to a settlement that provides more certainty about the dates by which EPA will review the Colorado State Implementation Plan for ozone. 
  • The deferral from September 14, 2007 to November 20, 2007 will provide time for the settlement to be published in the Federal Register, and for EPA to take public comment on the settlement.  


  • In April 2004, the EPA published a final rule designating areas of the country as either meeting or not meeting the ground-level ozone National Ambient Air Quality Standards (NAAQS), also called the 8-hour ozone NAAQS.  If an area fails to meet health-based national air quality standards, the Clean Air Act requires an area to implement a number of efforts to improve air quality by a certain date.
  • EPA is working with several areas across the country to reduce ground-level ozone, or smog, as quickly as possible.  Together with EPA, 29 areas entered into agreements called Early Action Compacts.  The Compacts give areas the flexibility to develop their own approach to meeting the 8-hour ozone standard, provided they achieve clean air sooner than the Clean Air Act would otherwise require.
  • Fifteen of these communities already met the 8-hour ozone standard when they chose to join the compact.  The communities joined to ensure that they stay in attainment and to take voluntary steps to protect the health and quality of life in their communities. By reducing pollution ahead of schedule, these communities are bringing sustainable health and environmental improvements to their residents sooner than without these agreements.
  • Early Action Compacts require communities to:
    • Develop and implement air pollution control strategies,
    • Account for emissions growth, and
    • Achieve and maintain the national 8-hour ozone standard.
  • Early Action Compact areas must attain the 8-hour ozone standard no later than December 31, 2007.  Any EAC area that does not meet the standard on that date will be designated as not meeting the standard by April 15, 2008, which will trigger the mandatory Clean Air Act requirements to reduce ground-level ozone.
  • EPA will withdraw the deferral if an area misses any milestone set out in its Early Action Compact.
  • In November 2006, EPA deferred the date that certain Clean Air Act requirements become effective for 13 Early Action Compact areas to April 15, 2008, and deferred the effective date for Denver’s requirements until July 1, 2007.  EPA then deferred Denver again to September 14, 2007.
  • The Denver EAC has a separate deferral date from the other EAC areas because Colorado under-estimated emissions from oil and gas exploration. The state has since adopted a new rule to ensure additional reductions from the industry.
  • In addition to working with areas that are participating in Early Action Compacts, EPA is also working with local governments, States and Tribes that are not participating in an Early Action Compact to develop an implementation strategy for the 8-hour ozone standard.
  • Ground-level ozone B the primary component of smog B is formed in the atmosphere on hot, sunny days.  The main ingredients of ozone come from cars, trucks, power plants, refineries and other large industrial facilities, and some natural sources.
  • When inhaled, even at very low levels, ozone can:
    • cause acute respiratory problems;
    • aggravate asthma;
    • cause significant temporary decreases in lung capacity in some healthy adults;
    • cause inflammation of lung tissue;
    • lead to hospital admissions and emergency room visits; and
    • impair the body's immune system defenses, making people more susceptible to respiratory illnesses, including bronchitis and pneumonia.


  • Today’s final rule and other background information are also available either electronically at http://www.regulations.gov, EPA’s electronic public docket and comment system, or in hardcopy at the EPA Docket Center’s Public Reading Room.
    • The Public Reading Room is located in the EPA Headquarters Library, Room Number 3334 in the EPA West Building, located at 1301 Constitution Ave., NW, Washington, DC.  Hours of operation are 8:30 a.m. to 4:30 p.m. Eastern Standard Time, Monday through Friday, excluding Federal holidays.
    • Visitors are required to show photographic identification, pass through a metal detector, and sign the EPA visitor log.  All visitor materials will be processed through an X-ray machine as well.  Visitors will be provided a badge that must be visible at all times.
    • Materials for this final action can be accessed using Docket ID No. EPA‑HQ‑OAR‑2003-0090.

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