The U.S. Environmental Protection Agency (EPA) has provided details on its proposal to further reduce oxides in nitrogen (NOx) from heavy-truck emissions beginning in model year 2027.
EPA Administrator Andrew Wheeler signed and released a draft copy of the proposal, known as the Cleaner Trucks Initiative (CTI), on Jan. 6 as an Advanced Notice of Proposed Rulemaking (ANPR) to soon be formally published for public comment. Wheeler announced a general outline of the initiative in November 2018.
EPA is attempting to align new standards for NOx (which contributes to ground-level ozone pollution) with Phase 2 carbon dioxide (CO2) standards, which are also scheduled to take effect in 2027. This would provide four to six full model years of lead time, allowing manufacturers to implement a single engine redesign.
"Through this initiative, we will modernize heavy-duty truck engines, improving their efficiency and reducing their emissions, which will lead to a healthier environment," Wheeler said at a press conference in Marshall, Virginia, outside Washington, D.C. "The U.S. has made major reductions in NOx emissions, but through this initiative we will continue to reduce emissions, while spurring innovative new technologies, ensuring heavy-duty trucks are clean and remain a competitive method of transportation."
The push by EPA for new NOx standards – which have not been revised since 2001 – was initiated in 2016 in response to a petition from a coalition of 20 state and local government agencies, led by California, urging lower emissions from trucks. The goal, EPA stated at the time, "is to develop a program that could be adopted by EPA and the California Air Resources Board, creating a 50-state program" to ease compliance for truck manufacturers and fleet owners.
"To this end, the trucking industry seeks one national, harmonized NOx emissions standard that will result in positive environmental progress while not compromising truck performance and delivery of the nation's goods," commented American Trucking Associations (ATA) Vice President of Advocacy Bill Sullivan regarding the ANPR. "ATA is committed to continuing to work closely with EPA on developing the next generation of low-NOx-emitting trucks."
Owner-Operator Independent Drivers Association President Todd Spencer said his group, which represents small-business truckers, appreciated EPA's work over the last year to understand how pollution regulations affect his members, after earlier revisions left them "justifiably wary" of new proposals.
"We're hopeful our ongoing conversations with EPA and the feedback our members will soon provide during the ANPR comment period will lead to the development of an acceptable new standard," Spencer said.
In its 2016 petition, the coalition asked that EPA tighten NOx standards from the current 0.2 grams NOx per brake horsepower-hour (g/bhp-hr) to 0.02 g/bhp-hr – a 90% reduction that is currently an optional standard in California. In asking that industry inform the agency on a new federal standard, EPA pointed out that "only natural gas and liquefied petroleum gas engines have been certified" to the 0.02 standard.
In addition to comments on how natural gas could be used to reduce NOx – including potential government incentives – EPA asked industry to comment on how hybrid, battery-electric and fuel cell vehicles could be used to further reduce NOx.
The agency said it also intends to propose longer emissions warranty periods for NOx reduction components because current warranty periods of five years or 50,000 to 100,000 miles (whichever comes first) do not reflect real-world operations. "A longer emissions warranty period could provide an extended period of protection for purchasers, as well as a greater incentive for manufacturers to design emission control components that are more durable and less costly to repair," according to the proposal.
EPA said the increasing use of telematics services as a result of the Federal Motor Carrier Safety Administration's electronic logging device mandate could be used to measure and communicate NOx emissions to manufacturers in real time.
"By being able to schedule repairs proactively or otherwise respond promptly, operators would be able to prevent or mitigate failures during in-use operation and make arrangements to avoid disrupting operations."
EPA said it intends to publish a formal notice of proposed rulemaking later this year after reviewing comments. The formal rule proposal will likely take a closer look at specific standards, costs, and the effect new standards could have on fuel economy.