ALWAYS BEWARE of news released quietly from the White House on a Friday afternoon.

It's usually something the administration hopes will not attract a lot of attention as America's focus turns to the weekend. Which probably means the news isn't something the president wants to brag about.

Certainly that definition should apply to the circumstances of last Friday. The Bush administration put out the word that it was going to let power plants and other polluting industries take a pass on federal requirements that they clean up their acts.

Eastern states downwind of some dirty, old coal-fired plants in the Midwest consider the administration's decision so threatening to the health and welfare of their citizens that nine, including Maryland, are trying to block it in federal court.

Maryland's incoming Republican governor, Robert L. Ehrlich Jr., hasn't decided whether to stick with the decision his Democratic predecessor, Parris N. Glendening, made to join the lawsuit. But he should endorse it enthusiastically.

This isn't a partisan fight against the Bush administration. Six of the eight other states involved either have current or recently elected Republican governors.

The conflict here is regional. The East Coast states have been waiting 25 years for the Midwest industrial polluters to fall within the protections of the Clean Air Act.

When the law was passed in 1977, existing utility plants and other facilities were exempted from the strict new curbs on smokestack emissions until they were renovated or expanded. The bargain was made to spare plant owners the expense of making immediate improvements with the understanding that if the time came when the owners were in a position to upgrade, the pollution controls could be installed then.

Dozens of such power plants remain, contributing 25 percent of the pollution from fossil fuels while generating 11 percent of the electricity from such sources.

But now the plant owners want to expand their facilities without making the additional investment to meet higher pollution control standards. And the Bush administration has decided to let them. Administration officials argue that applying the tougher standards to older plants is counterproductive, because it discourages improvements that would increase energy efficiency and decrease air pollution that way.

The Eastern states don't buy it. They went to court two years ago, charging that many of the older plants were expanding without improved emission controls in violation of the 1977 law. The revised Bush rules would void that lawsuit, but the new legal challenge puts the issue before the courts again.

For Mr. Ehrlich, who hopes to hasten cleanup of the Chesapeake Bay despite a huge hole in the state's budget, supporting the move to reduce bay-polluting smog from the Midwest should be an easy call.