EPA Proposes Tighter NAAQS Standards For Ozone

Jun 21: U.S. EPA is proposing to strengthen the nation's air quality standards for ground-level ozone, revising the standards for the first time since 1997. The proposal is based on the most recent scientific evidence about the health effects of ozone -- the primary component of smog. EPA Administrator Stephen Johnson said, "Advances in science are leading to cleaner skies and healthier lives. America's science is progressing and our air quality is improving. By strengthening the ozone standard, EPA is keeping our clean air momentum moving into the future."

The proposal recommends an ozone standard within a range of 0.070 to 0.075 parts per million (ppm). EPA also is taking comments on alternative standards within a range from 0.060 ppm up to the level of the current 8-hour ozone standard, which is 0.08 ppm. The Agency will take public comment for 90 days following publication of the proposal in the Federal Register and will hold four public hearings. The hearings will be held in Los Angeles and Philadelphia on August 30, and in Chicago and Houston on September 5.

EPA says that since 1980, ozone levels have dropped 21 percent nationwide as the Agency, states and local governments have worked together to continue to improve the nation's air. Ground-level ozone is not emitted directly into the air, but is created through a reaction of nitrogen oxides and volatile organic compound emissions in the presence of sunlight. Emissions from industrial facilities, electric utilities, motor vehicle exhaust, gasoline vapors, and chemical solvents are the major man-made sources of these ozone precursors.

EPA also is proposing to revise the "secondary" standard for ozone to improve protection for plants, trees and crops during the growing season. The secondary standard is based on scientific evidence indicating that exposure to even low levels of ozone can damage vegetation. EPA is proposing two alternatives for this standard: a standard that would be identical to the "primary" standard to protect public health; and a cumulative standard aimed at protecting vegetation during the growing season.

EPA is estimating the health benefits of meeting a range of alternative ozone standards based on published scientific studies and the opinion of outside experts. These findings will be detailed in a Regulatory Impact Analysis to be released in the next few weeks, which will include both the estimated costs and benefits. EPA projects that health benefits of the proposed standard could be in the billions of dollars. However, EPA does not consider costs in setting ozone standards.

The American Lung Association (ALA) said it was pleased that the EPA is calling for tighter standards and it was "a step toward cleaner air;" however, the organization said, "the agency’s plan falls short of the goal recommended by its own scientific experts [Clean Air Scientific Advisory Committee (CASAC) Ozone Review Panel, See WIMS 10/25/07]. We are particularly concerned that the EPA has left the door open to choosing options that are simply not acceptable. We have reason to be concerned... Under today’s proposal, the EPA could tighten the smog standards to 75 parts per billion (ppb), a clear improvement, but far short of the 60 to 70 ppb unanimously recommended by the scientists after they conducted an extensive review of the evidence. Alarmingly, the new EPA plan leaves the door wide open to an option the American Lung Association considers unacceptable: Making no improvements in the standards at all by retaining the current standard."

The United States Chamber of Commerce said, “It would be ludicrous for EPA to revise any NAAQS [National Ambient Air Quality Standards], let alone the standards for ozone, without first considering the impact of these extraterritorial emissions.” The Chamber made the comment in a release that applauded the Task Force on Hemispheric Transport of Air Pollution (HTAP), which released a draft interim study finding that emissions from foreign nations constitute a significant share of the background ozone levels; which they said would make it "very difficult for localities to meet the new more restrictive standards being proposed by the Environmental Protection Agency (EPA) in its National Ambient Air Quality Standards (NAAQS)." The Chamber's vice president for Environment, Technology and Regulatory Affairs Bill Kovacs said, “This confirms what the Chamber has been saying for years: emissions from China, India, Mexico, and Africa don’t just disappear—they come to the United States.” The Long Range Transboundary Air Pollution (LRTAP) Executive Body created the Task Force on Hemispheric Transport of Air Pollutants.

The Chamber said that lowering the current standard of 84 ppb to either 70 ppb or 60 ppb, as recommended by the Science Advisory Board, would double, or even triple, the number of U.S. counties in non-attainment. They said the economic consequences of non-attainment are serious -- "non-attainment counties can lose federal highway and transit funding; restrictive permit requirements deter companies from building new plants or modifying existing ones; and mandated federal pollution control measures inhibit business expansion as local plans for economic development are put on hold."

Access an EPA release (click here). Access EPA's 2007 Proposed Revisions to Ground-Level Ozone Standards website with links to background information, a fact sheet, the Proposed Rule and Tech Support Documents (click here). Access a release from ALA (click here). Access a release from the U.S. Chamber (click here). Access the HTAP recently revised executive summary (click here). Access the draft chapters of the 2007 interim report for review and discussion at a May HTAP Task Force Meeting (click here). Access the HTAP website (click here). Access additional information on the LRTAP (click here). Access a release from Sierra Club (click here). Access a release from the Union of Concerned Scientists (click here). Access a release from Environmental Defense (click here). Access the Clean Air Scientific Advisory Committee (CASAC) Ozone Review Panel website for their review documents (click here). [*Air]