The Trump administration's Environmental Protection Agency is proposing to rewrite rules that limit pollution from heavy trucks but that the EPA says slow the economy.
Acting EPA Administrator Andrew Wheeler argues that new technology can help improve air quality, noting that the regulation of harmful nitrogen oxide emissions hasn't been revamped since 2000.
EPA officials were to announce the plans Tuesday but offered few details and said they were just beginning a regulatory process that can take years.
"We are doing it because it's good for the environment," said Wheeler, who notes that the EPA is under no requirement to redo the regulation. "Our goal is to update our standards so that we can get these new technologies in use across the country."
The proposed "Cleaner Trucks Initiative" is drawing expressions of hope but skepticism from some environmental groups, especially because the EPA under President Donald Trump already has proposed relaxing emissions requirements for light passenger cars and trucks by freezing them at 2020 levels.
Andrew Linhardt, the Sierra Club's deputy director for clean transportation, said his group is wary, and it wants to see details. Linhardt said he would favor the adoption of rules that would reduce nitrogen oxide emissions but doubts that the administration wants to do that.
"Unfortunately, this administration and this leadership of the EPA do not fill us with much confidence that this will be a real air pollution reduction measure," Linhardt said.
Paul Billings of the American Lung Association said he thinks the idea is encouraging but depends on exactly what the proposal looks like.
"The devil's always in the details," Billings said. "If they were not to tighten the (nitrogen oxide) standards, it'd be a bait-and-switch."
Nitrogen oxides can worsen existing lung disease, contribute to the development of asthma and increase susceptibility to respiratory infections.
Since the emissions regulations were last updated in 2000, regulatory requirements have been added piecemeal, resulting in what Wheeler calls "overly complex and costly" requirements that don't benefit the environment. The goal of the regulatory change would be to root out inefficiencies and perhaps use onboard diagnostic computers to ensure compliance over the life of trucks, Wheeler said.
The share of overall pollution contributed by heavy trucks has grown over the years, especially in urban areas and port cities with significant truck traffic, said Bill Wehrum, assistant administrator of the EPA's Office of Air and Radiation.
Wehrum said the EPA doesn't have a proposed target for setting new nitrogen oxide standards because it's at the beginning of a rule-making process. He said vehicles are now tested for emissions on a treadmill-like dynamometer, which might not capture all high-emissions phases of engine operation. The new standards could cut emissions during high-pollution phases, he said.
California already is working on more stringent heavy truck emissions standards, and new federal standards could conflict with them. Wehrum said the EPA isn't drawing up its own standards to set up a confrontation with California, and it will work with the state on the new regulation.
The EPA's plan to freeze passenger vehicle fuel economy standards at 2020 levels would relax a regulation enacted at the end of the Obama administration. But that plan already has touched off a legal fight with California and about a dozen other states that follow its rules. California wants the requirements to become progressively more stringent through 2026.
For now, the U.S. and California standards match, and the auto industry fears they could be split in two, forcing them to make costly design changes for California and the other states.
The EPA is still considering the light-vehicle standards. Its preferred option would freeze them so the fleet would be required to average 30 miles a gallon in real-world driving from 2021 to 2026.
AP writer Ellen Knickmeyer contributed from Washington.