Collected from the Environmental Protection Agency and the state, the grant money has helped the district buy 33 school buses that run on compressed natural gas (CNG). While the buses represent only about 10 percent of the district's fleet, their impact is far-reaching. Besides helping the environment, the buses serve as an example that other school districts might want to follow.

"We feel good about running the CNG buses," said James Hinckle, transportation director for the district. "They're better for the students and the environment, and they make a lot less noise."

Hinckle took over the transportation department several years after the district started its program to switch some of its buses to alternative fuels. It was his continued push, however, that resulted in the district receiving a $180,000 Clean School Bus USA grant in 2006.

This grant, along with those collected in the past, was offered in conjunction with the Utah Clean Cities Coalition as part of the Wasatch Front Clean School Bus initiative. The grants pay the difference in cost between a bus that runs with a diesel engine and an engine that runs on compressed natural gas. The most recent grant the district collected added another five CNG buses to its fleet.

Beverly Miller, director of the Utah Clean Cities Coalition, has worked with three transportation directors from the Jordan School District during the past 10 years. She says the district is one of a few in the state that have been bold enough to switch from diesel fuel.

"A school-district fleet is a huge operation, and it takes tenacity to go through with these types of changes," she said.

According to information submitted in the district's 2003 grant application - the application netted the district $350,000 for 10 alternative-fuel buses - CNG buses produce significantly less air pollution than diesel-fueled buses without advanced emission controls.

A study comparing CNG and diesel emissions from 1997-model buses shows reductions in nitrogen oxides, carbon monoxide emissions and particulate matter for buses that run on CNG. Although hydrocarbon emissions are higher for CNG vehicles, those emissions are less toxic and less reactive to ozone formation.

A study of school buses published by the Union of Concerned Scientists states exhaust from diesel fuel - 90 percent of the nation's 454,000 school buses are powered by diesel - exacerbates asthma, lung disease, cancer and has been linked to premature death.

That group's 2002 national report for school-bus emissions gave Utah a barely passing grade for its buses in relation to public health. That, however, was prior to the progress made in the Jordan School District and others across the state. For example, Chevron USA is giving the Davis School District a $200,000 grant to retrofit some of its 230 diesel-powered school buses with pollution-control devices.

The EPA's Clean School Bus USA initiative aims to reduce students' exposure to diesel exhaust by installing effective emission-control systems on newer buses and replacing the oldest buses in the fleet with new buses that use alternative fuels. The EPA also awards grants for polices and programs that eliminate unnecessary idling by school buses.

The Utah Clean Cities Coalition is joining with the EPA in the administration of a $100,000 grant to create idling-reduction programs in school districts across the nation. This project includes policy and curriculum development by the nonprofit National Energy Foundation and the Environmental and Energy Studies Institute. The program involves six Utah and Nevada school districts, including the Cache County, Washington County and Salt Lake school districts. The Utah Clean Cities Coalition will provide a cost share of $115,000.