California seeks to ban sales of diesel big rigs in a bold bid to cut pollution – and to save money
The first time California regulators attempted to implement a diesel emission limit, they ran into an unexpected problem: The state’s truck and bus fleet, which relies on diesel to drive more than half of its freight, has its own emissions standards to meet, and regulators did not have the authority to override those.
In the beginning, the state had to wait until 2017 to figure out whether it could do what it was seeking to do: set its own emissions standards for diesels without going through California’s traditional permitting process, even for the most routine changes – such as tweaking regulations for engines that use more fuel than those allowed by the state’s emissions standard.
Now the state has figured it out: The agency proposing to regulate diesels says it can override the standards set by California for light-duty trucks, buses and passenger cars because the standards are confusing.
“The state of California is essentially the ‘No Man’s Land,’” state Transportation Secretary Cheryl Engle told reporters in February, referring to an area of open land in which there is no road or infrastructure. The state is seeking to set its own emissions standards on a patchwork of routes. California has been waiting to figure out how to regulate diesels until the state can figure out the same thing.
Diesel trucks and buses, the biggest source of diesel pollution in California from 2013 through 2017, are regulated through an “end-use standard” in a rule that makes it a crime to exceed the California standards.
That approach would have been considered illegal by the U.S. Environmental Protection Agency, since the state was attempting to regulate a product that is exempt from that agency and other federal regulations. The EPA said in a letter that the California rules would conflict with its own regulations.
But the California Air Resources Board (CARB) found that the end-use standard was