New York City has traditionally regarded clean air as more of a journey than a destination. Since Congress passed the first Clean Air Act in 1970, ozone, smog, and particulate matter levels have decreased dramatically throughout the city and the surrounding region. Still, with the prevailing winds bringing in a fresh (or, rather, stale) supply of pollution every day, local levels remain disappointingly high when measured against most other regions of the country.

The Bush Administration says it would like to change that. In 2002 it proposed a new rule that it says will reduce emissions faster by introducing a more flexible permit process. Critics, however, argue that "flexibility" is simply a code word for relaxed standards and are fighting the proposal.

The Bush argument, which parallels that of administration allies in the coal and power industries, has it that the current interpretation of "major" is absurdly low. In 1999, for example, the Environmental Protection Agency filed seven lawsuits against utilities that had modified their facilities without reapplying for a new permit. In one suit, the agency cited a new furnace floor and replaced steam drum parts as sufficiently major modifications.

Utility industry lobbyists and the agency's current leadership argue that such strict interpretations -- and the cost of buying the new "best available" technologies that goes into qualifying for a new permit -- only encourages power companies to let their aging power plants grow dirtier and less efficient.

Given the challenge of cleaning up its own skies, you would think that New York City would be sympathetic to such arguments. Not so. Last March, together with the city of San Francisco and 27 Connecticut municipalities, the city joined in a 14-state lawsuit that aims to block the Environmental Protection Agency’s rule change.

For the city, the issue comes down to health care costs: More upwind pollutants means more asthma and more hospitalization cases.

"It doesn't take a genius to see that this is a rollback," says one city attorney close to the case. "If they're not rollbacks, the government has a role to explain why they aren't, and they haven't done that yet."

For decades, Republican lawmakers and their conservative Democratic allies pushed for compromises that would take regulatory power away from the Environmental Protection Agency. Now, states and municipalities, even as they flex their own regulatory muscles, are insisting that the federal agency retain its tough Clinton-era standards.

The one state leading the way is New York. Attorney General Eliot Spitzer has built on the successes of his predecessors in going after the out-of-state polluters whose smokestacks contribute to acid rain and other local problems.

Judith Enck, a policy advisor to Spitzer, says the Office of the Attorney General has targeted 30 coal-burning power plants both in New York and out of state over the last five years. Until last November, when the Environmental Protection Agency suspended ongoing investigations into 50 facilities, citing the rule change, the state was counting on the federal government to carry out a similar crackdown in other regions.

"Three years into the dance, we lost our partner," says Enck.

City lawyers, meanwhile, have undergone a role reversal. Only four years ago the city was the defendant in a civil lawsuit citing the Clean Air Act. Settled in 2000, the lawsuit stemmed from EPA charges that the New York City Department of Sanitation had been improperly handling discarded refrigerators and air conditioners, allowing the ozone layer-depleting freon inside to escape into the atmosphere. In the final settlement, the city agreed to pay a $1 million penalty and implement $3 million in new environmental programs.

Since then, the city has worked to get its own environmental house in order. Included in that effort are a series of epidemiological surveys studying the direct and indirect health impacts of air pollution on city residents.

One city attorney, speaking anonymously, says the Law Department was "happy to jump in" on the states' case, albeit in a background role.

The city has assisted the state in building its case mainly by offering local statistics on the hospitalization costs related to ozone and fine particulate matter -- the two local byproducts of increased upwind pollution. Dr. Thomas Frieden, commissioner of the city Department of Health and Mental Hygiene, says these statistics are the product of a two year long campaign to fill in the "major gaps" on local air pollution and its after-effects.

"What we know is that particulate matter and the amount of particulate matter in the air correlates with heart disease and death," Frieden says. "Both particulate and ozone are reasonable markers of air quality problems that may exacerbate asthma and other conditions for vulnerable people."

This linkage has been enough for the states’ legal argument to include dramatic information about health care in the city. Thanks in part to the city's data, federal judges have agreed to put the federal rules change on hold pending the outcome of the case. A three judge panel in the D.C. Circuit Court of Appeals, the primary venue for such policy disputes, made its decision on December 23, just three days before the revised policy was slated to go into effect.

Mike Leavitt, the new commissioner of the Environmental Protection Agency, says the agency will "vigorously defend" the new rule. He also maintains, however, that the agency, via the Department of Justice, would continue pressing the 1999 lawsuits filed under the old, Clinton-era interpretations.

Meanwhile, the former Utah governor has pushed the wind-borne pollutants debate into a new direction, unveiling the "Interstate Air Quality Rule." Aimed at the 29 states that currently fail to meet federal standards, the new rule would nationalize the "cap and trade" pollution credits program -- an outgrowth of the 1990 Clean Air Act.

"Our belief is simple: people do the right things faster, and they do more of it, when they have an incentive and the latitude to do it in a way that makes sense for them," said Leavitt in a Jan. 19 speech at the Edison Electric Institute, an electric utilities trade group.

Such comments, while rooted in federalist Republican doctrine, acknowledge the failures of a policing system that, to date, has allowed more than half the nation's states and 530 individual counties to skirt compliance. With air standards set to get even tougher in the coming years, it also acknowledges that, like it or not, the federal government has to play a stronger leadership role on the environmental front -- something Enck and her colleagues have been calling for all along.

"The EPA has been missing in action when it comes to air pollution," Enck says. "We truly want them involved in these cases."