by Dan Simon

The Wissahickon School District bus fleet includes a mix of old and new buses. ©GreenWorks photo by Dan Simon

Reducing the diesel engine emissions its buses produce will be a multi-step, long-term project said Joe Malseed, the head mechanic for the Wissahickon, Penn., School District. The good news is at least one of those steps is already underway.

"We've already started using a low-sulfer emission fuel," he explained. "What will happen is as the vehicles start using it, it will clean their engines. We're hoping it will reduce emissions from 18 to 30 percent per bus."

Right now the cleaner fuel is about nine to 15 cents a gallon more expensive than the fuel the school district had been using. Wissahickon is using a $250,000 grant from the state Department of Environmental Protection to help defray the costs of the effort.

The school district uses about 74 buses to transport some 4,000 students to and from school and various events. ©GreenWorks photo by Dan Simon

Malseed said he expects the price of the cleaner fuel to be less of an issue in the future because federal rules mandate that eventually all school buses will have to use it.

"We're getting a head start on it," he said. "It will take about three to six months for the fleet to clean up from the fuel."

Wissahickon, like most other school districts, has a fleet of buses of different ages. It replaces from three to six buses a year depending on a variety of factors including budget constraints and projected student populations. As a result, additional emission reduction measures will depend on the age of each bus.

"We're going to put particulate filters on the newest buses," he said. "Then there are converters similar to a car's catalytic converter, that we're going to put on some of the older buses."

The district's efforts include switching to a low-sulfer diesel fuel and adding filters or convertors to reduce emissions on many of the buses in its fleet. ©GreenWorks photo by Dan Simon

The particulate filters are the latest emission reduction technology available for the school buses and should be offered as an option on the models coming out next year. Malseed said that combined with the low-sulfer fuels, bus emissions should be reduced about 90 percent on the district's newest equipment.

"They're very impressive," he said.

The district's middle-aged buses won't fare quite as well with the new converters, but should still see as much as a 60 percent reduction in emissions. The oldest buses, which are only receiving the low-emission fuel should still see some improvement too.

"It wouldn't make sense to retrofit a bus we're trading in a year," he said.