The National Ambient Air Quality Standards EPA'S PROPOSED OZONE AIR QUALITY STANDARDS AND AGRICULTURE: FACT SHEET OVERVIEW OF ACTION • On Nov. 25, 2014, the U.S. Environmental Protection Agency (EPA) proposed to strengthen the National Ambient Air Quality Standards (NAAQS) for ground-level ozone, based on extensive scientific evidence about ozone's effects on public health and welfare. The proposed updates will improve public health protection, particularly for children, the elderly, and people of all ages who have lung diseases such as asthma. Today's proposal will expand the ozone monitoring season for many states, and update the Air Quality Index to ensure people are notified when air quality is unhealthy. And it will improve the health of trees, plants and ecosystems. • States would have time to develop and implement plans to meet revised standards, and existing and proposed federal rules will help by making significant strides toward reducing ozone-forming pollution. EPA projections show the vast majority of U.S. counties would meet the proposed standards by 2025 just with the rules and programs now in place or under way. • EPA has proposed to set both the primary (health) and the secondary (welfare) standards as 8-hour standards in a range from 65 to 70 parts per billion (ppb). The existing standards are both 75 ppb. The agency is taking comment on alternative levels for the standards. • The Clean Air Act requires EPA to set secondary standards to protect the public welfare, which includes trees, plants, crops and ecosystems. EPA analyses show that reducing ozone can improve yields for timber and some crops, such as soybeans and winter wheat. • EPA will take public comment for 90 days after the proposal is published in the Federal Register. The Agency will hold three public hearings. • EPA will issue final standards by Oct. 1, 2015. WHAT THE EXISTING OZONE STANDARDS HAVE MEANT FOR AGRICULTURE • Ozone, a key component of smog, forms in the atmosphere when emissions of nitrogen oxides and volatile organic compounds "cook" in the sun. Emissions from sources such as cars, trucks, buses, engines, industries, power plants and products such as solvents and paints are among the major manmade sources of ozone-forming emissions. Farm dust does not contribute to ozone formation. • Protecting and improving the nation's air quality is the work of a federal-state partnership established in the Clean Air Act. EPA issues national standards and designates the "nonattainment areas" that must reduce pollution in order to meet the standards. States then determine what those pollution reduction steps will be and outline those steps in plans known as "state implementation plans." • Like all national air quality standards, the existing ground-level ozone standards set the amount of ozone pollution allowed in the outdoor air. But the standards do not establish emission control requirements for any particular industry, including agriculture. Each state determines how to reduce an area's pollution to meet the standards in a way that makes the most sense for that area. 1 ------- • The vast majority of states have not required the agriculture industry to take any actions that require emission reductions, instead focusing their efforts on reducing emissions of the pollutants that form ozone from sources such as industrial processes and consumer products. • In California, some nonattainment areas are addressing ozone-forming emissions from agriculture by incorporating conservation management practices developed with growers and USDA into ozone implementation plans for those nonattainment areas. These include a menu of options growers can choose from, such spray application technologies or integrated pest management strategies, and limiting combustion emissions from engines by combining or reducing tillage operations to reduce the number of passes through fields. These commonsense practices also reduce emissions of VOCs and NOx. • In addition, the USDA Environmental Quality Incentives Program is helping reduce ozone-forming nitrogen oxides (NOx) emissions by providing financial assistance to farmers for replacing diesel engines that power agricultural equipment with lower-emitting models. WHAT EPA HAS PROPOSED Strengthening the primary (health) standard to improve public health protection • A significantly expanded body of scientific evidence shows that ozone can cause a number of harmful effects on the respiratory system, including difficulty breathing and inflammation of the airways. For people with lung diseases such as asthma and COPD (chronic obstructive pulmonary disease), these effects can lead to emergency room visits and hospital admissions. Ozone exposure also is likely to cause premature death from lung or heart diseases. • In addition, evidence indicates that long-term ozone exposure is likely to result in harmful respiratory effects, including the development of asthma. Asthma disproportionately affects children, families with lower incomes, and minorities, including Puerto Ricans, Native Americans/Alaska Natives and African-Americans. • EPA is proposing that the current 8-hour ozone standard of 75 ppb is not adequate to protect public health as the law requires and that the standard should be revised to improve public health protection for millions of Americans. • EPA is proposing to set the health standard within a range from 65 to 70 ppb and is seeking comment on levels for the primary standard as low as 60 ppb. The agency will accept comments on all aspects of the proposal, including on retaining the existing standard. Strengthening the secondary (public welfare) standard to improve protection for trees, plants and ecosystems • New studies since the last review of the standards add to evidence showing that repeated exposure to ozone reduces growth and has other harmful effects on plants and trees. These types of effects have the potential to impact ecosystems and the benefits they provide. • EPA is proposing to revise the level of the secondary standard to a level within the range of 65 to 70 ppb, the same range proposed for the primary standard. The agency is proposing that a standard in this range would provide appropriate protection against the cumulative ozone exposures that can affect ecosystems through damage to plants and trees. 2 ------- • In July 2013, the U.S. Court of Appeals for the D.C. Circuit upheld the 2008 primary ozone standard but remanded the secondary standard to EPA, on the grounds that the agency had not specified the level of air quality that was requisite to protect public welfare as required by the Clean Air Act, and had not clearly shown how the secondary standard provided this protection. The proposed revisions to the ozone standards respond to this remand. • EPA is proposing to identify the appropriate level of protection for trees, plants and ecosystems using a seasonal index that scientists often use to assess the impact of ozone on ecosystems and vegetation. This index is known as a W126 index, named for the equation used to calculate it. • EPA is proposing that air quality meeting a W126 index value between 13 and 17 parts per million- hours (ppm-hours), averaged over three years, would provide the degree of protection that the Clean Air Act requires. Ppm-hours is a measurement unit used to express the sum of weighted hourly ozone concentrations, combined over the 12-hour daylight period. EPA is proposing that this protection could be achieved by setting an 8-hour secondary standard in the range of 65 to 70 ppb. • EPA is seeking comment on this target level of protection. In addition, EPA is seeking comment on achieving the necessary protection by revising the secondary standard to a W126-based standard within a range of 13 to 17 ppm-hours, averaged over three years. EPA also is seeking comment on retaining the current secondary standard. FOR MORE INFORMATION: • More detail on the proposed standards: http://epa.gov/glo/pdfs/20141125fs-aqi • Proposal and additional fact sheets visit http://www.epa.gov/glo/actions.html • Commenting instructions: http://epa.gov/glo/pdfs/20141125fs-comment.pdf 3 ------- |