Metro bus retrofits, new fuel help bring cleaner air

A New Flyer articulated bus like the one above is the first in Metro's fleet to get a new catalytic soot filter that, together with new ultra-low sulfur diesel fuel, will reduce emissions by more than 90 percent. It's part of a broad regional coalition to transform the market to the new, cleaner fuel.

King County Metro is joining with other local governments and private companies to clean up existing fleets of diesel engines in the region through engine retrofits and the early introduction of low sulfur fuels.

U.S. Environmental Protection Agency Administrator Christine Todd Whitman joined King County Executive Ron Sims and Seattle Mayor Paul Schell on July 10 to launch the Puget Sound Diesel Solutions Program, a model program to make diesel engines in this region dramatically cleaner. For King County, this effort will involve the retrofitting of 800 buses during the next two years.

Metro introduced new clean-diesel buses in 1996 that reduced vehicle emissions by 90 percent. This new program will reduce soot emissions and toxic emissions by another 90 percent and cut hydrocarbon emissions to undetectable levels.

The program has two parts: using new ultra-low sulfur diesel fuel that is now coming to market and replacing existing mufflers with new catalytic soot filters. Tosco Refining also announced its commitment to produce ultra-low diesel fuel at its refinery in Ferndale, five years earlier than required by the EPA.

A 60-foot articulated bus was retrofitted with the new catalytic mufflers on June 5. Since then, the bus has been driven 2,000 miles with the new fuel with no visible soot in its exhaust stream, no exhaust odor and no loss in performance or fuel efficiency.

All future buses bought by Metro will be equipped with this new technology. The ultra-low sulfur diesel fuel is already available at Metro's East Base in Bellevue. Other bases will get this fuel beginning early next year. Buses operating out of East Base will also be the first to be retrofitted.

When Metro's retrofit of 800 buses is complete, they will travel 31 million miles and use 9 million gallons of the new fuel per year--and Metro will have the one of the cleanest-burning bus fleets in the nation.