WASHINGTON, D.C. — The U.S. EPA announced on Thursday that it is awarding $30 million for clean diesel projects as part of its “ongoing campaign to reduce harmful diesel exhaust that can lead to asthma attacks and premature deaths.”

School buses are among the vehicles being replaced or retrofitted in the latest round of funding for the Diesel Emission Reduction Program, also known as DERA.

Here are details on some of the pupil transportation-related projects:

• The Colorado Department of Public Health and Environment is being awarded $700,000 for retrofitting an estimated 186 diesel school buses with diesel oxidation catalysts, crankcase filtration systems and fuel-operated heaters.

• The Maine Department of Environmental Protection is getting $1.39 million for replacing four school buses with compressed natural gas buses and for repowering two vessels with two marine propulsion and four auxiliary engines to Tier 3.

• The Idaho Department of Environmental Quality is being awarded $290,000 for retrofitting 12 school buses and 20 pieces of construction equipment with pollution control devices.

• Sioux Falls (S.D.) School District is being awarded $450,000 for replacing 18 school buses.

• Aldine Independent School District in Houston is getting $1.04 million for retrofitting 65 school buses with diesel particulate filters.

To view the full list of projects that have been awarded for fiscal year 2012, go here.

The EPA said that winners were selected based on proposals' potential for maximizing health and environmental benefits by targeting areas that have significant air quality issues.

“Reduced air pollution from diesel engines in these areas can have a direct and significant impact on community health,” the agency said.

DERA was enacted in 2005. Since it was first funded in fiscal year 2008, the EPA has awarded more than 500 grants nationwide. According to the agency, these projects have "reduced hundreds of thousands of tons of air pollution and saved millions of gallons of fuel.”

In September, the EPA announced its first-ever rebate program (also under DERA). The pilot will focus specifically on replacing older school buses. The agency said it anticipates that the rebate application acceptance period will start in November.