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Release Date: 05/17/2000
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The U.S. Environmental Protection Agency today proposed a major action to protect the public health and the environment of all Americans by reducing the sulfur content in diesel fuel by 97 percent to provide for the cleanest-running heavy-duty trucks and buses in history. By addressing diesel fuel and engines together as a single system, harmful emissions from diesel and gasoline heavy trucks and buses will be reduced up to 95 percent -- the clean-air equivalent of eliminating air pollution from 13 million of today’s trucks.

“Anyone who has ever driven behind a large truck or bus is familiar with the smell of diesel fuel and the clouds of thick exhaust emissions. Today’s action would cut this harmful air pollution by more than 90 percent,” said EPA Administrator Carol M. Browner. “The Clinton-Gore Administration already has produced the toughest tailpipe standards ever for passenger cars, minivans, sport utility vehicles, and pick-up trucks. This proposal takes the next big step to achieve cleaner air. It will provide dramatically cleaner heavy-duty trucks and buses. The result will be significantly healthier air for all Americans.”

This action, in combination with other actions EPA is taking to improve air quality, such as controlling pollution from power plants and passenger cars, will help ensure that more than 120 million people across the country will be able to live in areas that meet national health standards for clean air. This proposal would reduce smog-causing nitrogen oxides from these vehicles by 95 percent, and it would reduce particulate matter, or soot, by 90 percent. In the United States, every year, smog and particulate matter (soot) account for 15,000 premature deaths, one million respiratory problems, 400,000 asthma attacks, and thousands of cases of aggravated asthma, especially in children.

An older, dirtier diesel vehicle can emit almost 8 tons of air pollution per year. There also is increasing evidence that diesel exhaust may cause lung cancer in humans. This proposal would reduce 2.8 million tons of smog-causing nitrogen oxides emissions each year once the program is fully implemented. Emissions of soot would be reduced by 110,000 tons each year.

To date, most diesel trucks and buses have not used pollution control devices such as catalytic converters, similar to the devices that have been used on cars for the last 25 years. To enable pollution-control technology to be effective on trucks and buses, diesel fuel must be significantly cleaner than it is today. EPA has proposed a reduction in the sulfur content of highway diesel fuel from its current level of 500 parts per million to 15 parts per million – a 97 percent reduction. Diesel engines are more durable and have higher fuel economy than gasoline engines. With lower-sulfur fuels and advanced technology, they also will be able to burn more cleanly as well.

This proposal requires diesel and gasoline engines to meet stringent emission standards. These standards would result in the first broad use of emission control devices such as three-way catalysts and soot traps on these engines. Diesel engine manufacturers would have flexibility to meet the new standards through a phase-in approach between 2007 and 2010. Gasoline engine manufactures will have to meet the standards in 2007.

EPA has designed this proposal to include significant lead time for the introduction of new cleaner fuel into the marketplace and to ensure no disruptions in fuel supply. The proposal also discusses various flexible phase-in approaches for the diesel fuel industry to facilitate the complete transition to new clean diesel fuel and to reduce costs further. The fuel provisions would go into effect in June, 2006. EPA is seeking comments in its proposal on ways to incorporate additional flexibility for small oil refiners.

Today’s action, coupled with other actions regarding diesel engines taken by the Clinton Administration, would produce clean-air benefits that will provide as much reduction in air pollution as will the tough new tailpipe standards for passenger vehicles that President Clinton announced last December. Those standards are the toughest ever for passenger vehicles and require cars to be 77 to 95 percent cleaner than those on the road today. Beginning in 2004, light-duty trucks, mini-vans and sport utility vehicles will have to meet the same tailpipe-emission standards as passenger cars. Also, that rule requires a 90 percent reduction in the sulfur content of gasoline.

There will be five public hearings regarding today’s proposal. The hearings will take place in New York, Chicago, Atlanta, Denver and Los Angeles. Following the public hearings, there will be a 45 day comment period. Instructions on submitting written comments are in the Federal Register notice. EPA plans to finalize its proposal by the end of this year. The proposed rule and related documents are available electronically via the EPA Internet site at:

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