Seemingly acting out of character, the U.S. Environmental Protection Agency on Nov. 13 announced it will launch a rulemaking to further cut the emission of nitrogen oxide from diesel-powered heavy-duty trucks. EPA said it intends to publish a proposed NOx rule in early 2020.

While the EPA under President Trump has beenheavily engaged in rolling back dozens of environmental rules, the agency could now be said to be aiming to promulgate a single federal rule to forestall a patchwork of federal and state rules on NOx emissions from commercial vehicles.

Indeed, even as California moves toward writing new state emissions rules, trucking and truck-manufacturing lobbying groups along with state environmental officials have been pushing EPA to set a new nationwide rule on allowable NOx emissions for diesel trucks. California would actually prefer a national rule, if it is tight enough, as more than half the trucks delivering goods there are registered in other states.

EPA has tagged its new effort as the “Cleaner Trucks Initiative,” which Acting Administrator Andrew Wheeler said will include a “future” rulemaking that will update the existing (federal) NOx standard, which was last set in 2001. In addition, he said the new rule would “streamline” compliance and certification requirements.

“The Cleaner Trucks Initiative will help modernize heavy-duty truck engines, improving their efficiency, and providing cleaner air for all Americans,” said Wheeler, speaking at a public announcement in Washington that was shown live online.“The U.S. has made major reductions in NOx emissions, but it’s been nearly 20 years since EPA updated these standards. Through rulemaking and a comprehensive review of existing requirements, we will capitalize on these gains and incentivize new technologies to ensure our heavy-duty trucks are clean and remain a competitive method of transportation.”

“Today’s announcement makes clear that reducing NOx emissions from heavy-duty vehicles is a clean air priority for this administration,” said EPA Office of Air and Radiation Assistant Administrator Bill Wehrum. “EPA’s Cleaner Trucks Initiative is an important signal to all interested stakeholders that we will work hard on reducing emissions while producing a more effective and efficient program.”

EPA is not required by statue to update the NOx standard. However, in a news release, the agency asserted that although U.S. NOx emissions fell by more than 40% from 2007 to 2017, “there is more work to be done.” EPA estimates that heavy-duty trucks will be responsible for one-third of NOx emissions from the transportation sector in 2025. The agency said “any update to the standards will result in significant mobile source NOx reductions, which will aid communities across the country in the attainment of ozone and particulate matter standards.”

Referencing the agency’s rollback already of over two dozen regulations since Trump took office, EPA said that in addition to NOx emissions standards, the “CTI will cut unnecessary red tape while simplifying certification of compliance requirements for heavy-duty trucks and engines.”

The agency said that “areas of deregulatory focus will include onboard diagnostic requirements, cost-effective means of reassuring real world compliance by using modern and advanced technologies, the deterioration factor testing process, and concerns regarding annual recertification of engine families.”

Commenting on the EPA initiative, John Mies, manager of corporate communications for Volvo Group North America (parent of Volvo Trucks North America and Mack Trucks) told HDT that the OEM “supports the agency’s decision to investigate whether additional NOx reductions are needed to address any of the nation’s last remaining air quality challenges.

“This is a great opportunity to update and streamline the certification and compliance processes, ensuring a focus on real-world emissions control with minimal impediment to market vitality,” he continued.

Mies added that, historically speaking, trucking has “delivered dramatic emissions reductions in response to EPA’s leadership in developing challenging but practical national emissions regulations.”

The American Trucking Associations also applauded EPA for “taking the first step” toward issuing new NOx standards. “As an industry engaged in interstate commerce, ATA strongly favors a single national emission pathway as opposed to a patchwork of state standards,” ATA Executive Vice President of Advocacy Bill Sullivan said in a statement.

He pointed out that trucking has “repeatedly demonstrated that it can work proactively and in partnership with the federal government in achieving these aims. We look forward to working with the EPA in developing a standard that achieves nationwide air quality improvements across the country while maintaining a strong and robust economy.”

Global diesel engine maker Cummins Inc. also announced support for the EPA effort. “Cummins has a long history of working with regulators to help develop tough, clear and enforceable standards that lead to a cleaner, healthier and safer environment,” said Jennifer Rumsey, vice president and CTO. “We can and should do more to reduce NOx. This is an important step forward because a streamlined, national regulatory program brings consistency across the country allowing manufacturers to develop cleaner, more cost-effective solutions for our customers.”

The Diesel Technology Forum advocacy group said that EPA’s action “follows petitions for rulemaking from a number of state and local air agencies, as well as support for a new low NOx standard from truck and engine makers. The EPA last revised these standards in January 2001. The CTI proposal [rulemaking] is slated to be released in 2020.”

DTF added that it expects the planned low-NOX rulemaking for trucks will “help bring today's generation of diesel even nearer to zero emissions than ever before.”

Truck and Engine Manufacturers Association President Jed Mandel called the Cleaner Trucks Initiative “a tremendous opportunity. We – EPA and the manufacturers – have done this before, and we’re ready to step forward to do it again. We ask the agency to follow that same successful roadmap by leading a collaborative, open regulatory process involving all stakeholders.”

Mandel also stated that adopting a national low-NOX truck program with sufficient regulatory lead time, stability and certainty will be essential to provide a clear path for [truck and engine] manufacturers to succeed. “By working together,” he said, “we believe we can reduce emissions and improve and streamline the compliance program while at the same time preserve the necessary diversity of the commercial vehicle marketplace and protect the needs of our customers for durable, reliable products.”

Daimler Trucks North America, in a statement issued on Nov. 14, said it “strongly supports the EPA’s initiative to streamline regulatory requirements and improve air quality, while maintaining a regulatory framework that encourages reliable, durable products with low total cost of ownership.” 

Sean Waters, DTNA’s director of regulatory compliance, said the OEM is “confident that the Cleaner Air Initiative will provide real world emission reductions, streamline certification and compliance, and continue to enable us to provide vehicles with the best TCO.”

EPA has set up a website devoted to its new Cleaner Trucks Initiative.

Updated Nov. 15 at 4:10 pm EST to add Daimler Trucks North America comments.