– A federal judge ruled May 6 that the South Coast Air Quality Management District (SCAQMD) may enforce its seven clean fleet rules, according to the Progressive Newswire.U.S. District Judge Florence-Marie Cooper issued her 24-page opinion in Los Angeles in response to a motion filed in January by the Engine Manufacturers Association and Western States Petroleum Association seeking to invalidate SCAQMD's fleet rules in their entirety."This lifts a legal cloud cast by the U.S. Supreme Court over a large portion of our fleet rules," said Dr. William A. Burke, governing board chairman of the SCAQMD. "We can now continue to implement major portions of our fleet rules, which are essential to our strategy for reducing both smog-forming and toxic emissions in the Southland."In her ruling, Judge Cooper stated that in requiring state and local government fleet operators to purchase the cleanest available vehicles, SCAQMD was acting as a market participant, not a regulator. In the case of state and local government agencies, the fleet rules are not preempted by the federal Clean Air Act, Cooper ruled. "The Fleet Rules, as applied to state and local governments, fall within the market participant doctrine," Cooper said in the conclusion to her opinion. "They are not preempted. Plaintiff's challenge fails. Plaintiff's motion is denied."SCAQMD's governing board adopted its fleet rules in 2000 and 2001. The seven fleet rules target primarily diesel-powered vehicles, including transit buses, school buses, trash trucks, airport shuttles and taxis, street sweepers, and heavy-duty utility trucks. The rules generally require fleet operators to buy clean-fueled models when they replace vehicles or add to their fleets of 15 or more vehicles. As a result of the rules, more than 5,500 clean-burning heavy-duty vehicles, powered by natural gas and other clean fuels, have been added to the region's fleets.SCAQMD is the air pollution control agency for Orange County and major portions of Los Angeles, San Bernardino, and Riverside counties.