Air Panel Delays Decision on Phasing Out Diesel Buses

California’s air quality board on Thursday delayed a decision on a far-reaching regulation that would gradually replace polluting diesel transit buses with cleaner technologies.

After a six-hour hearing, state Air Resources Board Chairman Alan Lloyd said that too many concerns remained about the proposal to adopt it immediately. Several board members were particularly concerned that the measure would take too long to remove soot-emitting diesel buses from California’s roads, especially in the heavily polluted Los Angeles Basin.

Under the proposal, 85% of the soot emitted by new diesel buses would be eliminated over the next decade. But as the proposal now stands, transit agencies in the state would have the option to keep buying diesel buses for several years as long as they follow other steps to cut emissions, such as installing soot traps and using low-sulfur fuel.

Most transit agencies endorsed the proposal, calling it reasonable. But environmentalists and Los Angeles regional air quality officials were strenuously opposed, saying that it failed to push hard enough in requiring natural gas and other cleaner, alternative technologies.

Several board members asked the staff to come back next month with a new proposal that would accelerate the switch to alternative fuels, especially in the most polluted areas of the state.

Soot in diesel exhaust has been linked to cancer and other serious health problems.