The U.S. Environmental Protection Agency (EPA) approved a more stringent National Ambient Air Quality Standard (NAAQS) for ground-level ozone (aka "smog"). From the EPA announcement:
EPA today met its requirements of the Clean Air Act by signing the most stringent 8-hour standard ever for ozone, revising the standards for the first time in more than a decade. The agency based the changes on the most recent scientific evidence about the effects of ozone, the primary component of smog.
"America's air is cleaner today than it was a generation ago. By meeting the requirement of the Clean Air Act and strengthening the national standard for ozone, EPA is keeping our clean air progress moving forward," said EPA Administrator Stephen L. Johnson.
The new primary 8-hour standard is 0.075 parts per million (ppm) and the new secondary standard is set at a form and level identical to the primary standard. The previous primary and secondary standards were identical 8-hour standards, set at 0.08 ppm. Because ozone is measured out to three decimal places, the standard effectively became 0.084 ppm: areas with ozone levels as high as 0.084 ppm were considered as meeting the 0.08 ppm standard, because of rounding.
Although the standard is, as EPA noted, the most stringent ozone NAAQS ever adopted, it is not as stringent as that recommended by the EPA's Science Advisory Board. Also of note, EPA Administrator Stephen Johnson stated he wants Congress to give the EPA authority to consider costs when setting NAAQS under the Clean Air Act. The Washington Post reports:
The Environmental Protection Agency yesterday limited the allowable amount of pollution-forming ozone in the air to 75 parts per billion, a level significantly higher than what the agency's scientific advisers had urged for this key component of unhealthy air pollution.
Administrator Stephen L. Johnson also said he would push Congress to rewrite the nearly 37-year-old Clean Air Act to allow regulators to take into consideration the cost and feasibility of controlling pollution when making decisions about air quality, something that is currently prohibited by the law. In 2001, the Supreme Court ruled that the government needed to base the ozone standard strictly on protecting public health, with no regard to cost. . . .
Nearly a year ago, EPA's Clean Air Scientific Advisory Committee reiterated in writing that its members were "unanimous in recommending" that the agency set the standard no higher than 70 parts per billion (ppb) and to consider a limit as low as 60 ppb. EPA's Children's Health Protection Advisory Committee and public health advocates lobbied for the 60-ppb limit because children are more vulnerable to air pollution. . . .
Rogene Henderson, who chairs the agency's Clean Air Scientific Advisory Committee, said in an interview that she disagrees with Johnson's decision even as she welcomed a tighter standard.
"We can't kid ourselves that this is as health protective as we would like, but this is a step in the right direction," Henderson said. "I understand that with our dependence on fossil fuels, it's difficult to reduce ground-level ozone. But the fact that it's difficult doesn't mean it's not worth doing."
A slew of industries had recently urged White House officials to keep the current limit, effectively 84 ppb, to minimize the cost of installing pollution controls. The EPA estimated that it will cost polluting industries $7.6 billion to $8.8 billion a year to meet the 75-ppb standard, but that rule will yield $2 billion to $19 billion in health benefits. . . .
Under the Clean Air Act, the federal government is obligated to reexamine the science underpinning its smog standards every five years. The agency last revised the standards in 1997, and 85 counties have yet to meet those rules.
As both industry and environmentalist groups are unhappy with the new standard, litigation will surely follow.