Supreme Court voids So. Calif. emissions mandate

Supreme Court voids So. Calif. emissions mandate

The U.S. Supreme Court dealt Southern California smog fighters a blow when it ruled against air quality rules credited with putting more than 5,500 clean and low emission vehicles on the region's roads.

The justices voted 8-1 on April 28 to block the South Coast Air Quality Management District from applying a clean air mandate to the operators of private vehicle fleets.

The ruling didn't specifically address public fleets, according to South Coast, instead leaving that decision to a lower court that had previously ruled in favor of the regulators.

Wednesday's Supreme Court ruling is the result of a challenge to South Coast's 2000 decision to require fleet operators to choose natural gas vehicles or something cleaner when making new purchases.

Diesel engine manufacturers, the petroleum industry and the Bush administration argued against the rules.

They accused the AQMD of overstepping its bounds by regulating vehicles, a job typically left to the state and federal governments.

Although air quality regulators said the ruling doesn't hamper their efforts to regulate public and some other fleets, the Engine Manufacturers Association, a diesel engine trade group that argued the case in front of the court, disagreed.

They said the ruling vindicated their argument that emission standards should be set nationally so manufacturers can build engines to a single standard.

The San Francisco-based 9th U.S. Circuit Court of Appeals had upheld the tougher local rules, but the decision was voided by the high court. The Supreme Court sent the case back to California to consider the issues.

Justice Antonin Scalia, writing for the court, said that the emissions rules appear to be blocked by the federal Clean Air Act.

"If one state or political subdivision may enact such rules, then so may any other; and the end result would undo Congress's carefully calibrated regulatory scheme," he wrote.

Justice David H. Souter filed the only dissent. Souter, who is from New Hampshire, said he disagreed that the Clean Air Act "prohibits one of the most polluted regions in the United States from requiring private fleet operators to buy clean engines that are readily available on the commercial market."

The Clean Air Act gives states some authority to set their own rules. At issue in Wednesday's case were local standards.