California officials say they are forging ahead with emissions-cutting measures despite the Trump administration's move this week to delay implementation of Obama-era limits on ozone, the lung-searing gas in smog.
"We are committed to working with states and local officials to effectively implement the ozone standard in a manner that is supportive of air quality improvement efforts without interfering with local decisions or impeding economic growth," Pruitt said in a statement.
The extension applies to a tougher 70 parts per billion limit on ozone the Obama administration EPA adopted in October 2015.
The move is the latest in a series of steps Pruitt has taken to roll back or delay Obama-era environmental protections. The decision is expected to push back federal deadlines to reach the health standard, allowing states with dirty air, including California, to put off the adoption of pollution-reduction measures.
California regulators insisted that Pruitt's decision would in no way delay progress in cleaning the air.
"California is forging ahead with aggressive actions to reduce ozone levels, irrespective of EPA's delay," California Air Resources Board spokesman Stanley Young said. "In the meantime, we believe that EPA cannot back off on its own responsibility to set cleaner standards."
Young cited the "critical public health challenge" of air pollution in Los Angeles and the San Joaquin Valley. He said steps that California regulators are taking to reduce emissions in the freight and transportation sector "will put us on the trajectory for meeting the 70 [parts per billion] standard in any case."
Ozone is a corrosive gas that forms when emissions from smokestacks and tailpipes cook in the heat and sunlight. It triggers asthma and other respiratory illness. Southern California has the nation's worst ozone pollution and remains far from meeting a series of previous federal air quality standards.
Environmentalists blasted the EPA's move as a step toward rolling back the Obama administration's clean-air standards and allowing industries to avoid stronger emissions controls.
"This delay is a flagrant violation of the law that denies Americans their right to safe air free from unhealthy smog pollution," said John Walke, clean air director for the Natural Resources Defense Council, an environmental group.
Industry groups waged a fierce lobbying and advertising campaign against the 2015 ozone rules, predicting they would harm businesses by requiring costly new pollution controls.
In his previous job as attorney general of Oklahoma, Pruitt was one of the top legal adversaries seeking to block the EPA's regulations on climate change, clean water and air quality, suing the Obama administration over its 2015 ozone standards and other major environmental rules.
After Trump appointed Pruitt administrator, the EPA began reexamining its ozone rules.
EPA records show all 50 states and the District of Columbia submitted recommendations last year on which areas should be designated as meeting or violating ozone limits. None said they had insufficient information to do so.
The EPA did not respond to requests for comment, including questions about what specific information it lacks and the potential health consequences of the delay.
Republican lawmakers who have long been critical of Obama's environmental regulations applauded Pruitt's decision.
"This regulation was yet another attack on the middle class by the Obama Administration and was forced through despite significant concern from communities across the country," U.S. Senate Majority Leader Mitch McConnell (R-Ky.) said in a statement.
Tougher ozone standards, achieved quickly, would benefit tens of millions of Americans who live in counties with unhealthy air. That includes 17 million people in Los Angeles, Orange, Riverside and San Bernardino counties who breathe the nation's worst-polluted air. After decades of reducing ozone levels, progress has faltered in recent years.
This year, ozone has exceeded the 70 ppb ozone standard on 37 days. That's up from 33 days during the same time last year and 21 days in 2015, according to South Coast Air Quality Management District data through Monday.
Clean-air advocates say that means California pollution regulators must do more locally to reduce emissions. California adopted its own 70 ppb ozone standard in 2005, citing the threat to children's health.
AQMD spokesman Sam Atwood said "the best path forward toward meeting this standard is the one we are on now — implementing all feasible measures, fostering cleaner technologies and accelerating deployment of zero- and near-zero technologies."
In 2015, the EPA estimated that achieving the 70 ppb limit by its 2025 deadline would prevent hundreds of thousands of asthma attacks and missed school days for children and hundreds of early deaths from cardiovascular disease and other illnesses. It also said the savings from those health benefits would outweigh the billions of dollars in annual costs to the industry by about 4-1.
Obama gave California extra time to comply — until 2037 — because of the severity of its air pollution.
California air quality officials say they expect the EPA to extend the deadline until 2038.
Under the Clean Air Act, the EPA is required to review its air quality standards for ozone and other pollutants every five years and adjust them if necessary to reflect the latest health science.
Ozone is such a widespread pollutant that obligations to keep reducing it have vexed previous administrations.
The administration of George W. Bush rejected recommendations for a tougher limit when it adopted the 2008 ozone standard of 75 ppb.
Obama’s EPA vowed to tighten ozone rules but set aside EPA administrator