CARB Aggressively Pursues Tougher NOx and PM Emissions Reductions

truck exhaust

California environmental regulators are aggressively moving forward with plans to require significant reductions in nitrogen oxides and particulate matter emissions for heavy trucks, improvements in “real time” on-board diagnostics, and lengthening the “useful life,” durability and warranty periods for heavy trucks.

The changes under consideration were the subject of a four-hour public workshop on Jan. 23 in which staff members of the California Air Resources Board outlined their plans, which drew concerns from heavy truck manufacturers.

Current plans call for proposal of a new NOx standard to the CARB board in early 2020 that is expected to reduce the current NOx ceiling of 0.2 gram per brake horsepower-hour to between 0.015 and 0.035 gram per brake horsepower-hour. Officials said they do not know when the new standard would take effect, nor what it will ultimately be.

Other Regulatory Changes Being Considered by CARB

• A reduction in particulate matter emissions by as much as one-half of the current level.

• Lengthening the manufacturers’ warranty period for Class 8 trucks from the current standard of 350,000 miles to 800,000 miles and the truck’s current useful life from 10 years and 435,000 miles to 15 years and one million miles.

• Implement tighter durability demonstration requirements.

• A requirement that inventories of older, warrantied parts be maintained for 10 years.

• Issue amendments to more effectively assess in-use compliance under all operating conditions.

CARB officials have said the strict regulatory measures are critical for compliance with federal health-based air quality standards for ozone in 2023 and 2031 in the state’s South Coast and San Joaquin Valley air basins. On-road heavy-duty vehicles are responsible for about 33% of the total statewide NOx emissions, officials said.

However, executives for some truck makers urged the agency to give them time to meet the stringent new requirements, cautioning that engineering development also could cause a spike in the cost of new trucks.

“It’s really important for us to know if you’re looking at a .015 standard or a .035 standard this could create dramatically different hardware,” said Navistar executive Matt Smith. “This would have been a great rule to have had we known about it two years ago with all the details finalized because the gestation period for a lot of these products is seven to nine years. Any time we have to compress, stuff is going to get compromised. It’s going to be cost, timing or durability.”

A representative from CARB expressed empathy for his concerns.

“We don’t want to impose such a shock on the industry that it’s too hard, too expensive, or you have horrible durability problems,” said Kim Heroy-Rogalski, chief of CARB’s Mobile Source Regulatory Development Branch. “But we also don’t want everyone to wait until like 2026 to start working on it. We want you guys to be working on it now.”

Heroy-Rogalski added, “It’s a difficult thing for us, because we’re obviously trying to phase this in really fast because NOx reductions are urgently needed in California. I’m under a lot of pressure for public health reasons and for SIP [State Implementation Plan] reasons to move this fast.”

Although CARB staff members are said to be working with federal environmental regulators, officials with the U.S. Environmental Protection Agency were not present at the public workshop due to the partial federal government shutdown.

In November, EPA announced it has begun an environmental review to reduce nitrogen oxide emissions from heavy-duty truck engines. Top agency officials labeled the review effort their “Cleaner Trucks Initiative,” but offered little detail about their plans or how long it will take to update the NOx standard.

“We’re hopeful that EPA will come along given the fact that they’re shut down right now, and given the fact that their rulemaking process takes a couple of years due to a number of mandatory steps they have to go through,” Heroy-Rogalski said. “I’m guessing they’ll probably be coming behind us. But we intend to adopt standards for California regardless of what EPA does.”