In a rare demonstration of continuity between administrations, the EPA announced that in early 2020, it would propose regulations to reduce emissions of nitrogen oxide (NOx) from on-road heavy-duty trucks and engines.

The proposal would be part of the Cleaner Truck Initiative (CTI), which Acting EPA Administrator Andrew Wheeler unveiled in the company of representatives of the truck manufacturers industry, several unions, and the Environmental Council of the States, among others.

The CTI and the announced proposal would ostensibly fulfill a commitment the Obama EPA made in December 2016 in response to petitions from 20 entities, including state and local governments, asking that the Agency undertake a package of actions to update the existing NOx regulations for heavy-duty trucks, which were last revised in 2001. The EPA agreed that an update was in order and said it would propose one by July 2017 and issue a final rule by December 2017 (see memo). Although those dates were missed after the change in administrations, the current EPA asserts that revisions are still in order.

New technologies available

“The U.S. has made major reductions in NOx emissions, but it’s been nearly 20 years since EPA updated these standards,” said Wheeler. “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.”

Under the current standards, it is estimated that heavy-duty trucks will be responsible for one-third of NOx emissions from the transportation sector in 2025.

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,” says the Agency. 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.

In their June 2016 petitions, California’s South Coast Air Quality Management District (SCAQMD), the New York City Department of Environmental Protection, nine public health and medical associations, and other public and private entities requested four actions, including an “ultra-low” NOx exhaust emissions standard of 0.02 grams per brake horsepower per hour (g/bhp-hr), deadlines for compliance, and incentive funding for truck owners under the Diesel Emission Reduction Act (DERA).

Single national standard

The 0.02 g/bhp-hr NOx limit is currently being adopted in California on a voluntary basis. Regulatory agencies and industry have acknowledged the availability of new technologies that enable engines to exhaust at this low NOx level. In its memo, the EPA did not commit to issuing a mandatory 0.02 g/bhp-hr NOx limit, although the Agency agreed that a lower limit than what is now required should be part of a larger strategy that also includes improvements to test procedures and test cycles to ensure emissions reductions occur in the real world, updates to certification and in-use testing protocols, and lengthening the period of mandatory emissions-related component warranties.

A revised federal NOx limit could also dissuade California from acting on its own to promulgate new limits. The Clean Air Act allows California to issue its own on-road vehicle emissions standards, which must be at least as stringent as the federal standards. Once California finalizes such standards, other states may adopt them. In the case of heavy-duty trucks, this would lead to bifurcated regulations nationwide—a situation the CTI seeks to avoid.

“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,” commented Jennifer Rumsey, vice president and chief technical officer at Cummins Inc.

Enviro groups will wait and see

Announcement of the CTI was greeted cautiously by environmental groups, including the Natural Resources Defense Council (NRDC).

“Given its sorry overall record in protecting public health, we will be watching closely to make sure the Agency follows through and actually mandates the needed cuts in these smog-forming compounds,” said the NRDC. “There’s ample reason for skepticism.”

“Any plan to reduce dangerous nitrogen oxides pollution from big diesel trucks must be able to achieve protective real-world results—without the type of cheating we saw during the Volkswagen scandal,” said Vickie Patton, general counsel of the Environmental Defense Fund.

More information on the CTI is at https://www.epa.gov/regulations-emissions-vehicles-and-engines/cleaner-truck-initiative.