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Area Designations for 2008 Ground-level Ozone Standards

National Air Quality Standards for Ozone,
Final Designations - Questions and Answers


EPA is implementing the 2008 ozone standards as required by the Clean Air Act. EPA is taking the next step to implement the 2008 standards as quickly as possible. Meeting these standards will provide important public and environmental health benefits. EPA has worked closely with states and tribes to identify areas in the country that meet the standards and those that need to take steps to reduce ozone pollution.

EPA’s final designations are based on air quality monitoring data, recommendations submitted by the states and tribes, and other technical information including emissions, commuting patterns, population growth, weather patterns and topography. EPA will work closely with states and tribes to implement the standards using a common-sense approach that improves air quality, maximizes flexibilities under the Clean Air Act and minimizes burden on state and local governments.

Breathing air containing high levels of ozone can reduce lung function and increase respiratory symptoms, aggravating asthma or other respiratory conditions. Ozone exposure also has been associated with increased susceptibility to respiratory infections, medication use by asthmatics, doctor visits, and emergency department visits and hospital admissions for individuals with respiratory disease. Ozone exposure may also contribute to premature death, especially in people with heart and lung disease.

Reducing smog and improving air quality is a shared responsibility of the federal, state, local and tribal governments. EPA recognizes that air pollution can cross state boundaries contributing to violations in downwind states. National rules such as the Cross State Air Pollution Rule and clean vehicle and fuel standards and more locally focused state, tribal and local air quality programs will reduce pollution and protect public health. Most areas will be able to meet the 2008 standards as a result of recent and pending rules.


What areas does this action affect?

On May 31, 2012, EPA completed area designations for the 2008 ozone standards by designating the counties in the Chicago-Naperville, Illinois-Indiana-Wisconsin area, as meeting or not meeting the 2008 ozone standards. EPA designated the rest of the country on April 30, 2012.

Air quality continues to improve across the nation as a result of successful federal, state and local pollution reduction efforts. EPA designated 113 areas as not meeting the 1997 ozone standards set at 84 parts per billion. Less than half that number are not meeting the 2008 standards. In addition, many of the areas designated today cover a smaller geographic area than the previous standards.

Forty-six areas are designated “nonattainment” for the 2008 ozone standards. Two of these are tribal areas designated separately from the surrounding state areas for the first time.

Final designations for states: www.epa.gov/ozonedesignations/2008standards/state.htm

Final designations for tribes: www.epa.gov/ozonedesignations/final/tribalf.htm

Map of areas: www.epa.gov/ozonedesignations/2008standards/final/finalmap.htm

List of nonattainment areas: www.epa.gov/ozonedesignations/2008standards/final/finaldes.htm

Only three areas in two states (California and Wyoming) have not been nonattainment for previous ozone standards. Wyoming is the only state that has not previously had an area designated nonattainment for ozone.

What has happened so far in the process to designate areas for the 2008 ozone standards?

The designation process begins with state governors evaluating air quality monitoring data across their state along with other factors, such as sources of pollutants that form ozone and weather patterns, then making recommendations to EPA for how all areas in the state should be designated. Tribal leaders may also make area recommendations but they are not required to do so.

States and tribes provided their initial designation recommendations for the 2008 ozone standards in 2009 based on the most recent three years of air quality monitoring data generally 2006 to 2008. In 2011, many states and tribes provided EPA with updates to their original recommendations. EPA is making final designations using air quality monitoring data from 2008, 2009 and 2010 generally the most recent three years of certified data available and in some cases using data from 2009, 2010, and 2011. The Agency considered data through 2011 if a state certified it as complete and submitted it for consideration by February 29, 2012 2 months earlier than required.

What happens next in the process?

Each area that is designated as not meeting the 2008 standards is assigned a classification based on how close they are to meeting the standards. These classifications include Marginal (closest to meeting the standards), Moderate, Serious, Severe, and Extreme (farthest from meeting the standards). Most of the nonattainment areas (36) for the 2008 standards are initially being classified as Marginal. EPA expects these areas would be able to meet the standards within three years, usually as a result of recent and pending federal pollution control measures.

States with areas classified as Moderate or higher must detail control requirements in plans demonstrating how the areas will meet the 2008 ozone standards. Those plans are known as state implementation plans, or SIPs, and are expected to be submitted to EPA by 2015 - within three years of final designations. States may need to implement additional measures to control emissions of nitrogen oxides and volatile organic compounds the pollutants that react in the atmosphere to form ozone so that these areas attain the standards as soon as possible.

EPA continues to work on the next five-year review of the smog standards and currently expects to propose action in 2013.

What will states need to do to come into attainment?

The Clean Air Act requires state and local governments to take steps to control ozone pollution in nonattainment areas within their states and to address air pollution from their states that is adversely affecting air quality in downwind states. Those steps may include stricter controls on industrial facilities and additional planning requirements for transportation-related sources. Implementation requirements will be phased in over several years, and areas with worse problems will have more time to comply with the standards.

Nonattainment areas must implement “transportation conformity,” which requires local transportation and air quality officials to coordinate planning to ensure that transportation-related emissions from projects, such as road construction, do not interfere with an area’s ability to reach its clean air goals. Transportation conformity requirements become effective one year after an area is designated as nonattainment.

Major industrial sources of emissions of nitrogen oxides and volatile organic compounds the pollutants that react in the atmosphere to form ozone in nonattainment areas also are subject to new source review requirements. New Source Review is a permitting program for industrial facilities that ensures new and modified sources of pollution do not impede progress toward cleaner air.

Nonattainment areas classified as moderate or higher and are home to over 200,000 people must implement an inspection and maintenance program to control emission of smog forming compounds from vehicles. No areas will need to implement an inspection and maintenance program that do not currently have programs in place.

In areas that are designated “unclassifiable/attainment,” states will not have to take new steps to improve air quality, but they have programs in place, including monitoring and permitting programs to help prevent air quality in these areas from deteriorating to unhealthy levels.

How did EPA determine which areas were meeting or not meeting the standards?

After EPA sets a new National Ambient Air Quality Standard or revises an existing standard, the Clean Air Act requires the agency to formally determine whether areas are meeting the standards (attainment), not meeting the standards (nonattainment), or there is not enough information to make a determination at this time (unclassifiable). EPA is implementing the 2008 standards0.075 parts per millionas required by the Clean Air Act. A nonattainment area is one where air quality does not meet the ozone standards, and also includes nearby sources that contribute to poor air quality in the area.

EPA works closely with the states and tribes to make these decisions. States and, in many cases, tribes submit recommendations to the agency. The recommendations for the 2008 ozone standards were initially submitted in 2009, and many were updated in 2011. For the majority of the areas, EPA agreed with the states’ recommendation.

Why is EPA implementing the 2008 ozone standards now?

The Clean Air Act requires EPA to review and, if necessary, revise air quality standards every five years to ensure that they protect public health with an adequate margin of safety. Following a change in standards, EPA works with states and tribes as appropriate to identify areas that do not meet the standards and establish plans to improve air quality. In 2008, EPA set a new standard at 0.075 parts per million and EPA is taking the next step to implement these standards.
Working closely with the states and tribes, EPA is implementing the standards using a common sense approach that will improve air quality and minimize the burdens on state and local governments. Federal safeguards like the Mercury and Air Toxics Standards and the Cross-State rule and existing vehicle engine and tailpipe standards will significantly help many areas meet these standards without requiring additional action.

What is EPA doing to help the states meet the 2008 ozone standards?

History shows that cleaner air, better health and economic growth go hand-in-hand. Working closely with the states and tribes, EPA is implementing the 2008 ozone standards using a common sense approach that improves air quality, maximizes flexibilities and minimizes burden on state and local governments.
EPA recognizes that it shares the responsibility with the states and tribes for reducing ozone air pollution. Current and upcoming federal standards and safeguards, including pollution reduction rules for power plants, industry, vehicles and fuels, will assure steady progress to reduce smog-forming pollution and will protect public health in communities across the country.
EPA will be assisting state, local and tribal air agencies by identifying existing emission reduction measures as well as relevant information concerning the efficiency and cost-effectiveness of the measures. State, local and tribal agencies will be able to use this information in developing emission reduction strategies, plans and programs.  

For more information on the designation process for ozone, please visit: www.epa.gov/ozonedesignations/


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