A clean air agency can ban government agencies from using diesel-powered vehicles, according to a federal judge.

According to the Associated Press, the ruling upheld a ban on diesel vehicles in public fleets by the South Coast Air Quality Management District in Southern California.
The Engine Manufacturers Assn. and the Western States Petroleum Assn. had challenged the rule. The groups said the ban violated the federal clean air act, which generally prohibits state or local governments from imposing emissions standards stricter than federal regulations.
However, the judge said the regulations would only affect government purchases, not what manufacturers can produce and sell to other customers.
EMA says it will appeal the ruling. Jed Mandel, EMA general counsel, says the group disputes the court's reasoning that prohibiting the purchase of certain engines or vehicles is different from prohibiting their sale. "By regulating which new engines or vehicles customers can purchase, SCAQMD has in fact banned the purchase and sale of specific engine technologies - regardless of how low their emissions levels are. That ban is in direct violation of the federal Clean Air Act."
Mandel says that the court's rationale "could allow each locality across the country to establish its own separate emissions and purchasing requirements, forcing engine manufacturers to build engines in compliance with a chaotic patchwork of multiple standards."
The rules require public entities with fleets of 15 or more to buy alternative-fuel vehicles. The rules affect vehicles such as trash trucks, street sweepers, buses and airport shuttles in Los Angeles, Orange, Riverside and San Bernardino Counties.
For more on the controversial regulations, see "Southern California Public Fleets Will Have to Scrap Diesel," 6/19/2000.