MB Civic

Americans who live in areas with substandard air won another important round last week in the tortured legal battle to force power companies, other industrial polluters and the Bush administration itself to obey the Clean Air Act. In a unanimous decision, a federal appeals court in Chicago upheld a controversial provision of the act that requires older plants to install modern pollution controls whenever they undergo physical or operational changes that increase harmful emissions.

The provision, known as New Source Review, has been critical to the efforts of New York and other Northeastern states to reduce air pollution from Midwestern power plants. But industry hates it, and the administration has spent the last five years trying to get rid of it. This effort seemed very close to success until the courts intervened, delivering two rebuffs in less than half a year.

The first rebuff came in March when a three-judge panel of the Court of Appeals for the District of Columbia Circuit struck down an effort by the administration to redefine major modifications in power plants as “routine maintenance,” thereby placing them outside the scope of the law and sparing the power companies the need to invest in pollution controls.

Thursday’s decision, from a three-judge panel of the Court of Appeals for the Seventh Circuit in Chicago, turned on the question of how to measure emissions. The plaintiff in the case, Cinergy, a major Midwestern power producer recently acquired by Duke Energy, argued that the appropriate standard was the hourly rate of emissions. Judge Richard Posner, who wrote the decision, said that what counted was the plant’s annual emissions, since a plant that had been upgraded could presumably be driven harder, producing more emissions over time.

Both decisions are likely to be appealed, and the Supreme Court has already agreed to hear a case in which the Fourth Circuit, faced with the same arguments that confronted Judge Posner, produced the opposite result. But the fact that a distinguished conservative jurist like Judge Posner came down so clearly and sensibly on the side of the law has given clean air advocates hope that they, and the law itself, may yet prevail.