The South Coast Air Quality Management District (SCAQMD) has reached an agreement with the engine manufacturers to resolve a legal battle over district rules that require fleets of 15 vehicles or more to replace their older vehicles with ones using cleaner-burning alternative fuels. Under the agreement, the vehicle purchase rules will apply to local government fleets, but not those operated privately.

The case dates back to a rule promulgated by SCAQMD in 2000 that required any fleet, either private or public, to comply with clean vehicle purchase requirements. The Engine Manufacturers Association (EMA) filed a lawsuit claiming that the South Coast rules violated the Clean Air Act because the law only allows the federal government or the California Air Resources Board (CARB) to set vehicle emission standards, and not the air districts. While the federal district court and appeals court upheld the original South Coast fleet rules, in 2004 the Supreme Court reversed the lower court decision and sent the case back to district court to determine whether the fleet rules were not pre-empted under various legal doctrines.

The U.S. Ninth Circuit Court of Appeals ruled last year that SCAQMD’s fleet rules are not preempted by the Clean Air Act when they are applied to vehicle fleets owned by state and local governments. However, the court ordered the U.S. district court for the central district of California to decide whether private fleets are preempted from such rules. That court released a ruling on Feb. 7 that South Coast’s fleet rules are not preempted by the Clean Air Act so long as they only apply to fleets owned and operated by state or local governments, paving the way for the agreement between EMA and SCAQMD. The court rulings and agreements are important since many other air districts in California and throughout the country likely will adopt the SCAQMD rule.