CHICAGO – On August 20, the U.S. Ninth Circuit Court of Appeals issued a 33-page decision that can require state and local governments, as well as other publicly-funded fleets to purchase cleaner vehicles fueled by natural gas or other alternative fuels. This latest ruling upheld a majority of the fleet rules adopted by the South Coast Air Quality Management District (SCAQMD) in 2000.

The SCAWMD fleet rules applied to public and private fleets. While the Ninth District Court’s upheld the rules governing public sector fleets, it remanded the case back to the lower court where the mandates as applied to private fleets are expected to be ruled upon.

After a 2000 landmark SCAQMD study revealed that diesel exhaust contributed 70 percent of the total cancer risk from air pollution, the district established the first six of seven fleet rules to primarily target diesel-powered vehicles, including transit buses, school buses, garbage trucks, airport shuttles and taxis, street sweepers, and heavy-duty utility trucks. Generally requiring fleets with 15 or more vehicles to purchase “cleaner” vehicles, an estimated 6,000 new heavy-duty vehicles, mostly powered by natural gas, have been added to the region since the rules have been in place.

Though the Engine Manufacturers Association (EMA) claims the district’s rules banning diesel engines and fuels is outdated and does not take into account recent advances in fuel technology, the district is not convinced that diesel engines are anywhere near the level of clean as natural gas.

SCAQMD Governing Board Chairman William A. Burke strongly believes the clean fleet rules will benefit all Southern California residents, especially those most affected by the region’s poor air quality.

“We need these rules now more than ever to help us achieve strict federal air quality standards for particulate pollution by 2014,” Burke said.