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Pierce Transit's Clean Machines
A breath of fresh air: Pierce Transit powers its bus fleet with compressed natural gasAt Pierce Transit, we're proud to be known for our lean, green, "Clean Machines."
That's the nickname given to our buses powered by compressed natural gas (CNG) because they reduce nitrogen oxide and carbon monoxide emissions by 90 percent compared to their diesel-powered counterparts. Smog-producing hydrocarbon emissions are 80 percent lower, and CNG buses significantly reduce carbon monoxide (CO), and nitrogen oxide (NOx) emissions, and virtually eliminate particulate emissions, when compared to conventional diesel-powered vehicles. By contrast, diesel buses release a gallon of soot for every 570 miles traveled.
Pierce Transit's commitment to CNG began in 1986 when the agency launched a four-year demonstration project to test the feasibility of it as a fuel source for our bus fleet. We chose CNG for its environmental benefits and safety record. Working with the Washington State Energy Office and Washington Natural Gas (now Puget Sound Energy), Pierce Transit converted two 1974 GMC buses to run on both diesel and CNG.
When results were compared with six diesel buses of the same age, the agency found it cost less per mile in most cases to operate CNG buses. The engines also ran quieter, helping curb noise pollution in neighborhoods.
We're now completely committed to CNG. In 1992, we added a fast-fill compressor station, capable of refueling three CNG buses simultaneously in less than 10 minutes; a second station is now up and running. The agency bought the first low-floor buses in the state powered by CNG in February, 1999.
By 2004, the agency's entire fleet had been converted to alternative fuels.
While the fueling stations and their accompanying natural gas detectors and ventilation systems in the shop are expensive, fuel costs for CNG-powered buses can be much lower than for diesel-powered vehicles. In 2007, the CNG buses cost 33.4 cents per mile to fuel while diesel buses cost 44.6 cents per mile.
Pierce Transit's clean-air efforts have garnered a number of awards from such groups as the American Lung Association, the Natural Gas Vehicle Coalition, American Gas Association and the U.S. Department of Transportation. Most recently, the U.S. Department of Energy honored Pierce Transit with a Clean Cities National Partner Award.
The Department of Energy's Clean Cities awards promote the use of alternative, nonpolluting fuels. Pierce Transit was nominated for its award by the Puget Sound Clean Cities Coalition, a regional government/industry partnership led by the City of Seattle to promote the use of alternative fuels.
"As one of the country's first public transportation fleets to convert to alternative fuels, Pierce Transit is an alternative fuels pioneer," stated the award letter from Thomas J. Gross, the Department of Energy's deputy assistant secretary for transportation technologies. "Market surveys show that customers, as well as the general public, are familiar with and appreciate Pierce Transit's commitment to keeping the environment clean. Your efforts are significant and very much appreciated."
Pierce Transit will continue to explore ways to share resources and expertise because we believe the data we've accumulated make a strong case for the increased use of alternative fuels. More importantly, our experience with CNG shows that corporate citizenship and bottom-line efficiency can co-exist.
Want to know more about our Clean Machines? E-mail us.