California will require half of all heavy-duty trucks sold in the state to be electric by 2035, reports CNBC. The U.S. Environmental Protection Agency has given the state legal authority to implement this rule, as the mandate goes beyond federal requirements. The California Air Resources Board had sought two waivers from the Clean Air Act for the mandate.

“Under the Clean Air Act, California has longstanding authority to address pollution from cars and trucks,” EPA Administrator Michael Regan said in a statement. “Today’s announcement allows the state to take additional steps in reducing their transportation emissions through these new regulatory actions.”

Under the mandates, vehicle manufacturers will be required to produce zero-emission trucks starting next year. By 2035, 55% of delivery vans and small trucks, 75% of buses and larger trucks and 40% of tractor-trailers and other large vehicles sold in the state must be all-electric.

The California Air Resources Board estimates that the requirements will cut carbon emissions by nearly three million metric tons each year by 2040. Heavy-duty vehicles are responsible for nearly one-third of California’s nitrogen oxide and over a quarter of its fine particle pollution from diesel fuel, according to estimates from the board.

Opponents of the requirements say such regulations are costly and difficult to implement. The Truck and Engine Manufacturers Association said that the mandates would increase truck costs, and truck buyers would delay their purchasing of new heavy-duty vehicles. Reuters reports that American Trucking Association CEO Chris Spear said that “allowing the state to proceed with these technologically infeasible rules on unworkable and unrealistic timelines, the EPA is sowing the ground for a future supply chain crisis."

Others applauded the new regulations. “California has been hard at work passing landmark regulations to clean our air and protect our climate with zero emissions vehicles, so we’re heartened to see EPA stand with California today and grant this waiver,” Paul Cort, director of Earthjustice’s Right to Zero campaign, said in a statement.

In August, the California Air Resources Board passed a plan that requires all new passenger cars and light trucks sold in the state to be electric vehicles or plug-in electric hybrids by 2035. Currently, 16% of all new car sales in California are zero-emission vehicles.

NACS, along with other stakeholders, filed a petition in a federal court in Washington, D.C., challenging the Environmental Protection Agency’s waiver that would allow California to implement a zero-emission vehicle mandate.