By Suhrith Parthasarathy 

NEW YORK, Dec. 3 (Reuters) - When the U.S. Supreme Court hears a pair of cases challenging the Environmental Protection Agency today, it will do so without Justice Stephen Breyer, who has recused himself.

Breyer is a noted expert in administrative law and has tended to defer to the position of federal agencies in the past. By recusing himself, he may have deprived the EPA of an ally in two too-close-to-call challenges, which could determine how the agency handles certain logging permits.

Breyer's absence could therefore give an advantage to environmentalists, who are challenging the EPA in the two cases.

Under long-standing EPA policy, logging companies are exempt from securing permits for stormwater runoff. In the two lawsuits, originally filed in 2006, an environmental group says runoff is a major source of urban pollution and that the Clean Water Act in fact requires permits. The Oregon state agencies and timber companies who are the defendants in the lawsuits argue that the act does not mandate permits.

The district court ruled against the Northwest Environmental Defense Center, but the 9th Circuit Court of Appeals reversed in a unanimous decision in 2011. The defendants, including the Oregon State Forester, the Oregon Board of Forestry and a group of timber companies, appealed to the Supreme Court.

When the Supreme Court announced in June that it had granted certiorari, it noted that Breyer would be recused, though it did not disclose the reason, as is typical in recusal cases.

In the past, Breyer has disqualified himself in cases in which his brother, Judge Charles Breyer, a senior district judge for the Northern District of California, had played a role. Judge Breyer sat by designation on the 9th Circuit in both Georgia Pacific-West v. Northwest Environmental Defense Center and Decker v. Northwest Environmental Defense Center.

Before he joined the Supreme Court in 1994, Justice Breyer was a noted expert in administrative law and wrote two influential books on deregulation. His absence in the environmental cases could be considered a loss for the EPA and logging companies, experts said.

"Justice Breyer tends to be very sympathetic on the kinds of issues this case presents -- the Environmental Protection Agency's ability to interpret statutory language ... and t o address the problem at hand," said Richard Lazarus, who teaches environmental law and Supreme Court advocacy at Harvard Law School. "His is a vote I would think would have been inclined to favor the government's position here."

Without Breyer on the bench, the outcome of the cases is harder to predict. The most likely result is that the court's five conservative justices will vote together in support of the timber industry and reverse the 9th Circuit, said Michael Barsa, co-director of the environmental law concentration at Northwestern University Law School.

Alternatively, Justice Antonin Scalia, who is known to adopt the plain and textual meaning of a statute, could break ranks with his usual allies on the right and interpret the Clean Water Act to mandate permits for stormwater runoff, said Barsa. If Scalia votes with the more liberal members of the court, the vote could be 4-4.

A split would automatically affirm the 9th Circuit ruling, which would be a win for the environmentalists. As with all 4-4 votes, the decision would resolve the case at hand but would not set any precedent.

TO RECUSE OR NOT TO RECUSE

During each Supreme Court term, there typically are a handful of cases in which justices recuse themselves. Members of the court make those decisions based on a federal statute, court rules and personal judgment.

In its "Statement of Recusal Policy," the court spells out situations where a justice must bow out. These include cases in which a relative of a justice has appeared as a lawyer or a justice has a financial interest in the outcome. At the same time, the guidelines caution that members of the court should not go beyond the required recusals.

"Even one unnecessary recusal impairs the functioning of the Court," the policy says.

The recusal policy and the federal statute do not address whether a justice needs to recuse himself when a relative sits on a case under review by the court.

In choosing to step aside, Breyer would have had to rely on personal judgment to decide if anyone might question his ability to remain impartial, given his brother's role.

Because the justice has recused himself each time he has had to sit in judgment of his brother's decisions, the latest recusal became necessary to maintain consistency, said David A. Dana, a professor of environmental law and professional responsibilities at Northwestern Univeristy Law School.

Richard Painter, a professor at the University of Minnesota who co-authored a book on lawyers' professional responsibilities, isn't so sure about that. He said that Breyer's recusal was not strictly required and may have been ill-advised. "I am surprised with Justice Breyer's recusal. There is no financial interest involved here," Painter said. "I don't think the public would have thought him to be non-independent."

Justice Breyer and Judge Breyer declined to comment through representatives. Timothy Bishop, the Mayer Brown attorney representing the timber industry, and Jeffrey Fisher, the attorney representing the environmental group, also declined to comment on the cases.

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