Air Board May Ease Rule on Dirty Buses

In a move that would keep diesel-powered buses on roads in much of California, the state’s air-quality board today will consider a three-year delay in enforcing a smog-fighting standard that mandates cleaner-burning transit buses.

The Air Resources Board adopted a rule more than five years ago that requires all new transit buses beginning in 2007 to emit dramatically fewer nitrogen oxides, a key component of smog. But because no diesel buses will be able to meet that standard, the board is debating whether to allow six times more emissions until diesel technology can catch up in 2010.

Relaxing the standard would affect about 40 transit agencies, mostly in Central and Northern California, particularly the Bay Area, where cheaper diesel engines are still heavily used. In the smoggy Los Angeles Basin, the air board already requires all transit agencies to buy buses powered by alternative fuels, and most agencies have switched to compressed natural gas.

Diesel buses are among the largest sources of the emissions that create smog and soot, California’s worst air pollutants. There are about 10,000 transit buses in the state, around 60% of them diesel-powered.

The proposal seeks to reconcile California’s 2007 to 2009 emission standard of 0.2 grams of nitrogen oxides with a federal requirement of 1.2 grams. In 2010, all California buses must meet a federal standard of 0.2.

State air board officials said cleaner diesel technology did not progress as rapidly as they had predicted when the board adopted the standard.

Board spokesman Jerry Martin said delaying the standard by three years was not expected to increase emissions. On the contrary, he said, keeping it intact may actually be worse for air quality. Manufacturers would not be allowed to sell diesel engines in California for the three years, during which many transit agencies would buy no new buses and keep their older, higher-polluting diesel ones longer.

Of the 76 transit agencies statewide, 28 have chosen alternative fuels and six in the Los Angeles Basin will switch soon.

Transit agencies that are sticking with diesel say they are unwilling to spend millions of dollars for new natural gas fueling stations and equipment when cleaner diesels meeting smog standards will be available within five years. In the Bay Area, all but four of 21 transit districts buy diesel buses. Some say the natural gas buses could have maintenance problems in cold, hilly urban areas.

Diesel engine manufacturers say that although they cannot meet the standard for 2007, their pollution-control technology is improving rapidly and they expect diesel engines to be as clean as natural gas engines by 2010.

“The question becomes what is the most economical investment for public transit districts,” said Allen Schaeffer, executive director of the Diesel Technology Forum. “Is it a good use of public dollars to invest millions in natural gas pipelines and compressors when diesel could do it more cheaply, with the same environmental benefits -- freeing up funds for putting more buses in service or lowering fares?”

But environmental groups say relaxing the standard will allow agencies to continue buying dirtier diesel buses instead of cleaner alternative fuel ones and jeopardize air quality, particularly in areas where smog exceeds health standards, such as the San Joaquin Valley.

Environmentalists will ask the board today to keep the standard intact but allow agencies to buy new diesel buses if they retire some older, higher polluting ones in exchange.

“If [the air board] votes to weaken California’s bus emissions standards, they’ll be setting us back in the fight against air pollution, penalizing those engine makers that have invested heavily to develop cleaner engines that meet the 2007 standards, and letting a couple of transit agencies dictate policy for the whole state,” said Cary Brazeman of the California Natural Gas Vehicle Coalition, which represents makers of natural gas vehicles.

Brazeman said that if the looser standard was adopted, alternative fuel bus makers might decide to produce dirtier buses. Air board officials, however, called that unlikely because the major manufacturers, Cummins Westport and John Deere, have announced that they will introduce natural gas buses that meet the tougher standard in 2007.

Richard Hunt, a general manager who heads technology issues at the Metropolitan Transportation Authority, said if the state rule was changed, it would have no effect on bus purchases. Even if the board allows more emissions, he said, “every supplier has told us that they will be able to sell us” natural gas buses in 2007 that comply with the more stringent standard.

At the MTA and the Orange County Transportation Authority, some old diesels remain in their fleets but all the new buses run on compressed natural gas.

Some agencies are buying a newer clean-burning technology -- gasoline-electric hybrid buses. Long Beach Public Transit put Southern California’s first hybrid bus in service this year, with about 75 more coming soon.