Published June 2002

Community Transit aims to cut diesel exhaust emissions

By John Wolcott
Herald Business Journal Editor

Buses are true “working wheels,” an important part of Snohomish County's transportation system. Unfortunately, while mass transit buses reduce traffic congestion, their diesel-fueled engines still contribute to air pollution.

Now, Community Transit's directors have taken steps to help solve that problem. Last month they voted to slash diesel exhaust emissions by 90 percent by the end of 2005, a year before the Environmental Protection Agency deadline.

To reach that goal, the transit agency will begin switching to ultra-low sulfur diesel fuel in July and — over the next three-and-a-half years — its existing buses will be equipped with an exhaust “after treatment” system that re-burns exhaust gases.

Gary Nelson, Chairman of Community Transit's board of directors, said the changes will impact every person in the region.

“The Puget Sound region was recently ranked in the worst 5 percent for toxins in our air,” Nelson said. “Community Transit's board of directors felt it was important to begin converting our fleet to this new fuel as early as possible to help reduce pollution in our congested Puget Sound region. Adding these after-treatment systems will further reduce emissions and help keep the air we all have to breathe cleaner.”

Ultra-low sulfur diesel fuel produces just 15 parts per million (ppm) of sulfur in emissions, compared to the low sulfur diesel Community Transit currently uses, which can produce up to 500 ppm. Before the low sulfur diesel was developed, regular diesel fuel could produce up to 30,000 ppm.

The after-treatment system, a unit installed in the exhaust line, acts like a catalytic converter on a passenger car. A catalyst filters out particles, then the heat from the exhaust reacts with the catalyst and reburns the particles in the muffler. Unlike a catalytic converter however, the after-treatment unit can be taken apart and cleaned.

Ultra-low sulfur diesel fuel costs about 15 cents per gallon more than low sulfur diesel. During the next five years Community Transit estimates the ultra-low sulfur fuel will cost about $843,000 more than regular diesel. As EPA standards toughen between now and 2007, however, fuel costs will decrease as production of ultra-low sulfur diesel increases.

The after-treatment units cost $7,000 apiece, but that price will also drop as they become more common.

Community Transit will install the units on 41 coaches in 2002, 48 coaches in 2003, 83 coaches in 2004 and 38 in 2005. The unit will also be required on all of the 71 coaches Community Transit plans to buy between 2003 and 2005.

Community Transit operates 19 local bus routes, 33 commuter routes and Dial-A-Ride Transportation (DART) services throughout Snohomish County. It also offers carpool matching and a successful vanpool program that ranks as the third largest in the nation.

For more information, call Community Transit at 800-562-1375 for bus information or 888-814-1300 for carpool or vanpool information.

Related: Mobile command center to aid CT in emergencies

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