Plan to Require Cleaner Diesel Trucks Unveiled

New diesel trucks and other vehicles would be virtually exhaust-free beginning in 2007 under proposals announced Wednesday by the Clinton administration’s top environmental official and California’s air board chairman.

The proposed standards are designed to address rising concerns about the danger that diesel exhaust poses to people’s health. Diesel engines spew large quantities of tiny, soot-like particles that can lodge deeply in lungs and have been linked to cancer and respiratory disease. They also are a major contributor to California’s smog.

State Air Resources Board Chairman Alan Lloyd, while attending a symposium in Irvine on clean-air technologies, said near-zero emission trucks and other heavy duty vehicles are within reach.

This week he directed his staff to draft a proposal that would require manufacturers to cut particulates 90% and nitrogen oxides 75% by 2007 compared with today’s diesel engines. The standards would apply to new trucks, tractors, bulldozers and other farm and construction equipment.

The U.S. government is preparing to set national standards for diesel truck engines that are expected to be about the same. On Wednesday, Environmental Protection Agency Administrator Carol Browner said details of the EPA’s strategy are expected late this year or early next year.

“Anyone who has ever driven behind a large truck already knows about the levels of harmful air pollution that can come out of the exhaust pipes. This strategy would reduce those emissions by more than 90%,” Browner said.

As a result of air quality mandates, diesel engines have already been getting cleaner in the last 10 years, with new models no longer spewing clouds of black smoke. The new standards, if enacted, would cut exhaust so dramatically that a diesel bus or truck would be as clean as one that runs on natural gas.

“That’s wonderful. It’s something we’ve been advocating,” said Tim Carmichael, executive director of the Coalition for Clean Air, a Los Angeles-based environmental group. “There’s been so much information over the last decade and certainly over the last year about how nasty diesel exhaust is and how much harm it does to human health. We should be moving very aggressively to rid ourselves of our dependency on diesel fuel.”

State trucking industry officials say they would support the standards only if they were ordered nationwide. The state air board only has the power to regulate vehicles registered in California, but about 60% of trucks operating here are registered elsewhere and are regulated by the EPA.

“The technology is there and it’s the right thing to do,” said Stephanie Williams, environmental manager of the California Trucking Assn. “But you have to have a level playing field for the California trucker. We want clean air too, but we also want to stay in business. And we shouldn’t be punished just because we work in California.”

Manufacturers, under pressure to clean up trucks and other diesel vehicles, are close to perfecting pollution-reducing catalysts that would work on heavy duty diesel engines for the first time. They also are developing soot-capturing traps.

A major obstacle, however, lies in the state air board’s path: Diesel fuel must first undergo a formula change so it contains very little sulfur. Today’s fuel has so much sulfur that it would clog catalysts and filters.

“We’re confident that the technology will be there by 2007, but [the proposed standard] is dependent on very low sulfur fuel,” said air board spokesman Jerry Martin. “We’ve heard a lot of different manufacturers say they have technologies that they know will work.”

Browner said the EPA, within a few months, will propose a measure requiring a 90% cut in the sulfur found in diesel fuel. The requirement has been opposed by oil companies, because it would increase the cost of fuel and force major retooling of refineries.

Major engine manufacturers, such as Cummins, Navistar and Caterpillar, have spent millions of dollars on research in recent years. The biggest push driving the search for new technology came last year, when the California air board declared diesel soot a cancer-causing substance.

“The industry is seeing the writing on the wall,” the air board’s Lloyd said. He called the latest reports from manufacturers “very promising. It gives me a lot of encouragement that . . . we can get much cleaner air.”

Because a truck lasts about 30 years, the new technologies may take years to substantially reduce the cancer threat and smog problem posed by diesel engines.

Today, a new diesel truck puts out an average of 4 grams of nitrogen oxides and 0.10 of a gram of particulates per brakehorse hour, a standardized unit measuring heavy duty engine performance. Beginning in 2002, the nitrogen oxides allowed will drop to 2 grams under national standards already adopted.

The California rules proposed by Lloyd this week would be 0.5 of a gram or less for nitrogen oxides and 0.01 for particulates in 2007. A separate plan for buses has already been proposed by the state air board and would go into effect two years earlier, in 2005.

The EPA plans to change national truck standards to around the same levels as the state board proposes. Also, in its statement Wednesday, the EPA said it intends to reduce the sulfur content of diesel fuel “approximately 90% from its current level” of 500 parts per million.

During the last 30 years, the California air board has pioneered low-emission standards for a variety of vehicles that have had worldwide ramifications. In 1990, the board set stringent standards that required phased-in sales of low-emission and zero-emission cars. Since then, the technology has improved at a pace much quicker than anyone had imagined, and new gasoline-powered cars are virtually emissions free.

Lloyd, an expert in low-emission vehicles whom Davis appointed in February, has said his goal is to “count down to zero”--to push for vehicles that emit no pollutants.

The Coalition for Clean Air’s Carmichael said he will urge the air board to include requirements for some zero-emission diesel engines in its new proposal. Prototypes for exhaust-free trucks and buses, powered by fuel cells, are already available.

“It’s not going to happen tomorrow, but zero is an option, certainly by 2007,” he said.