The U.S. Environmental Protection Agency (EPA) has 45 days to file a petition for rehearing with the same three-judge panel that recently vacated the Cross-State Air Pollution Rule (CSAPR) at the U.S. Court of Appeals for the District of Columbia Circuit – or to seek review “en banc” by the full D.C. Circuit.

That translates to an Oct. 5 deadline for EPA.

“As a practical matter, we’ll probably know by early December whether the full court will agree to rehear the case,” said Jeff Holmstead, a power industry lawyer at Bracewell & Giuliani and former George W. Bush Administration EPA official.

“I think EPA will almost certainly seek rehearing en banc, but it’s highly unlikely it will be granted,” Holmstead said.

If the D.C. Circuit denies rehearing, EPA will then have 90 days to file a cert petition asking the Supreme Court to hear an appeal. "The Solicitor General’s office is the gatekeeper for any federal Department or agency that wants to file a cert petition, and the folks in that office don’t want to use their credibility with the Supreme Court to ask for cert unless it’s a good case for them and presents important legal issues worthy of Supreme Court attention,” Holmstead said.

Holmstead doubts the Solicitor General’s office will seek Supreme Court review, although the environmental community could push hard for the Obama Administration to take the case to the highest court. Even if the government does eventually seek Supreme Court review, Holmstead considers it “extremely unlikely” the high court would agree to take the case.

Many environmental groups have already urged EPA to seek a rehearing at the D.C. Circuit. The Natural Resources Defense Council, for example, says that the green cause has a good chance of getting of getting a rehearing. That is because the one dissenting judge made such a strong argument against the majority that it would force the entire bench to hear the case.

Others are saying that coal groups don't like the law as it was written in 2005, and now they don't like EPA's rewrite that occurred last year. Either way, coal is dissatisfied and can only boast of beating EPA. The first version of the law still stands.

Wayne Barber is chief of power generation for Generation Hub, an Energy Central unit.