EPA moves to reduce NOx on heavy-duty trucks

The EPA will look to redefine current NOx emissions levels for heavy duty vehicles. ( Photo: Shutterstock )

The EPA will look to redefine current NOx emissions levels for heavy duty vehicles. (Photo: Shutterstock)

In a surprise move, the Environmental Protection Agency has announced the Cleaner Trucks Initiative (CTI), which will try to rein in oxides of nitrogen (NOx) emissions from commercial vehicles. The agency said it will begin a formal rulemaking process for the program.

“This initiative will help modernize heavy-duty truck engines, improving their efficiency and providing cleaner air for all Americans,” EPA Acting Administrator Andrew Wheeler said, speaking to reporters. “We are under no regulatory or court order requirements to launch this initiative. We are doing it because it’s good for the environment.”

CTI differs from the Phase 2 Greenhouse Gas Emissions rule, which is being phased in through 2027. Phase 2 tackles carbon dioxide emissions (CO2) from commercial vehicles and built upon Phase 1, which ran from 2014 through 2018. The goal of Phase 2 is to reduce CO2 emissions by 270 million metric tons per year and was done so through the addition of aerodynamic devices and vehicle designs that emphasize fuel efficiency. It is estimated that by meeting Phase 2 regulations, U.S. fleets would save $50 billion a year in fuel costs.

CTI is attacking NOx levels, which hasn’t been addressed since the year 2001. Current NOx levels are set at 0.20 g/bhp-hr.

The California Air Resources Board (CARB) has led a coalition of states and clean air groups in pushing EPA to revise and lower NOx limits, citing technologies that are now available that can push the limits down further. CARB has pushed for a 90% reduction in NOx. But, those efforts, which began at the end of the Obama Administration, were expected to be for naught after the Trump Administration began taking down key parts of the Obama climate legacy. This included rolling back the EPA’s light vehicle mpg standards that would have required a 55-mpg average fuel economy for on-road vehicles. While it had not happened to the Phase 2 rules, there was some belief that the administration may do the same for commercial vehicles, especially once it announced an exemption from the rules for glider kits.

Under pressure, the EPA eventually removed the proposed exemption for gliders and has left the Phase 2 regulations untouched to this point.

In 2013, California set optional low-NOx standards with the most aggressive being 0.02 g/bhp-hr, which is 90% below the current standard. The state said the optional standards were developed “to pave the way for mandatory standards by encouraging manufacturers to develop and certify low NOx engines and incentivizing the purchase of certified low NOx engines.”

In an email to the Washington Post, CARB spokesperson Stanley Young offered cautious optimism on the development.

“It’s good that they are moving forward, because heavy-duty NOx is a huge problem, both as a precursor to ozone and fine particles,” he wrote, the Post reported. “CARB petitioned EPA to begin this process, as have many other state and local agencies, so we are pleased that the agency is moving forward to address the next generation of new heavy-duty engines.”

“The new Cleaner Trucks Initiative announced today sets the vision for the heavy-duty diesel engines of the future as high-value assets which help achieve our nation’s future energy and clean air goals while also expanding economic growth,” said the Diesel Technology Forum (DTF) in a statement. “Diesel has always been a technology of continuous improvement and this initiative sets the pace for the next generation of advanced diesel technology.”

DTF noted the progress over the years in the industry reducing NOx to its current levels – through the EPA 2007 and 2010 emissions rules – and believes the industry will again meet the challenge.

“Tremendous progress has been made in virtually eliminating criteria emissions from today’s generation of diesel engines. Consider that it would take more than 60 of today’s generation of diesel-powered heavy-duty commercial trucks to equal the emissions of a single U.S. model made in the pre-2000 era,” DTF said. “Modern diesel technologies of all kinds also deliver substantial reductions in greenhouse gas emissions, while preserving their superior fuel efficiency and performance characteristics.”

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The addition of SCR – selective catalytic reduction – technology to meet the NOx levels in 2010 added as much as $10,000 to the cost of a new truck.

The Truck and Engine Manufacturers Association (EMA) also applauded EPA’s move. Over the past 20 years EMA manufacturers have innovated and implemented advanced clean technologies to reduce NOx emissions by over 90% and particulate emissions by over 98%, EMA said.

“The Cleaner Trucks Initiative is 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,” said EMA President Jed Mandel. “Our members continue to increase fuel efficiency and lower greenhouse gas emissions in line with standards that will continue to challenge us through the next decade. EMA members are ready to build upon these successes to achieve even greater reductions.”