In one of the most far-reaching of numerous new air regulations expected from the Obama administration, the Environmental Protection Agency (EPA) has proposed to tighten the primary federal standard for ground-level ozone, the principal constituent of smog, to within a range of 60 to 70 parts per billion, saying the tougher standard is needed to protect human health.
The new primary ozone standard, which would be measured over eight-hour periods, is designed to protect children and other sensitive population groups from daily peaks of ozone, a noxious irritant that can exacerbate existing respiratory ailments such as asthma and trigger asthma attacks in healthy children, according to the EPA.
The new standard, if finalized, would replace the existing eight-hour standard of 75 parts per billion (ppb) set in 2008. The Bush-era standard was immediately challenged by states and environmental groups, who noted that then-EPA Administrator Stephen Johnson disregarded a recommendation by an EPA science advisory panel that he set the standard within a range of 60 to 70 ppb. EPA plans to issue the final standards by August 31, 2010.
Lower Recommended Limits
EPA Administrator Lisa Jackson signaled plans to review the ozone standards in March, when the Justice Department asked the U.S. Court of Appeals for the District of Columbia Circuit to freeze all legal challenges to the 2008 rulemaking to give the agency time to decide whether to revise the standard. Jackson announced in September the agency would reconsider the earlier rule.
EPA said that in reconsidering the earlier standard, the agency conducted a review of the science that guided the 2008 decision, including more than 1,700 scientific studies and public comments from the 2008 rulemaking process. EPA also reviewed the findings of the independent Clean Air Scientific Advisory Committee, which recommended standards in the ranges proposed by the new rule.
In a statement accompanying EPA’s announcement, Jackson said a tougher primary ozone standard was clearly needed and justified by the latest scientific data on the health impacts of ozone.
Depending on the level of the final standard, the proposal would yield health benefits between $13 billion and $100 billion, EPA said, citing projected reductions in premature deaths, aggravated asthma, bronchitis cases, hospital and emergency room visits and days when people miss work or school because of ozone-related symptoms.
EPA said the cost of a final standard of 70 ppb would range from an estimated $19 billion to $25 billion per year in 2020. For a standard of 0.060 ppm, the costs would range from $52 billion to $90 billion, EPA said. The Clean Air Act prohibits EPA from weighing costs when considering tightening a national ambient air quality standard.
Compliance Technologies Unclear
Notably, EPA acknowledged that its cost review assumed that the proposed standards can be achieved throughout the U.S. “using a mixture of known air pollution control technologies and unknown, future technologies.”
John Kinsman, senior director for environment at the Edison Electric Institute, the national association of investor-owned utilities, suggested that much of the burden of meeting the proposed standard would fall on power companies, but that other sources of ozone also would face significant costs.
“We probably won’t know for a couple of years just what utilities and other emissions sources will be required to do in response to a tighter ozone standard,” Kinsman said. “States will have to cast a very wide net when targeting sources for emissions cuts, in part because utilities already have made substantial reductions in ozone-related emissions.”
On the Road to Success
Ground-level ozone is formed when volatile organic compounds (VOC) combine with nitrogen oxides (NOx) in the presence of sunlight. Fossil fuel power plants produce less than 20% of national NOx emissions but emit virtually no VOCs, which typically come from motor vehicles, chemical manufacturers and oil refineries, among other sources.
In the eastern U.S., where ozone levels typically are highest, various Clean Air Act regulations issued by EPA since 1990 have reduced ozone-season NOx emissions by 75% since 1996 and about 62% since 2000.
However, a Bush-era rule aimed at helping states meet ozone and fine particulate standards set in 1997 was thrown out by the D.C. appeals court in 2008, although the court subsequently let the first phase of this rule, known as the Clean Air Interstate Rule (CAIR), remain in force to preserve air quality benefits already achieved. EPA, in addition to other regulations, is developing a new regulation to address a variety of objections raised by the court in its CAIR decision.
EPA also proposed to establish a new cumulative seasonal secondary ozone standard designed to protect sensitive vegetation and ecosystems, including forests, parks, wildlife refuges and wilderness areas, within a range of 7 to 15 parts per million.