The Supreme Court on Wednesday deferred to the Environmental Protection Agency in ruling that the stormwater runoff from logging roads is not a form of water pollution that needs a permit.

The victory for the timber industry came in the form of a 7-1 ruling in Decker v. Northwestern Environmental Defense Center and a companion case, Georgia-Pacific West v. Northwest Environmental Defense Center. Justice Anthony Kennedy wrote the decision in the case, which had become an important test of the court’s deference to administrative agency interpretations of their own regulations. Though endorsing the Environmental Protection Agency in this case, Wednesday’s ruling dropped hints that it may reconsider the deference issue when an appropriate case comes along.

The decision was one of two relatively low-profile rulings issued by the court on Wednesday. The other was Wos v. EMA, which declared that the federal Medicaid law pre-empts certain conflicting state restrictions. With the court in recess until next Monday, the justices’ output means that the court heads into next week’s historic oral arguments on same-sex marriage with a number of long-pending marquee cases still undecided. Among the awaited rulings, which could be released on the same day as the same-sex marriage arguments: Kiobel v. Royal Dutch Petroleum, argued last October 1, an important Alien Tort Statute case, and Fisher v. University of Texas, the affirmative action case that was argued October 10.

The Decker case involved runoff from logging roads in Tillamook State Forest in Oregon, with Kennedy noting that "it does often [rain] in the mountains of northwest Oregon." The Northwestern Environmental Defense Center, using a citizen-suit provision of the Clean Water Act, went to court alleging that the timber companies as well as the state forester of Oregon had violated the law, because no permits had been obtained for the runoff.

The group invoked a provision of the law that requires a permit for any discharges "associated with industrial activity." But another part of the law exempts discharges "composed entirely of stormwater." The EPA has long interpreted the law to exclude storm runoff from logging roads from the licensing requirement. The U.S. Court of Appeals for the Ninth Circuit ruled, however, that the logging road runoff was not exempted, in spite of the EPA’s interpretation.

But Kennedy chose to defer to EPA, asserting, "It is well established that an agency’s interpretation need not be the only possible reading of a regulation—or even the best one—to prevail." Noting that Oregon imposes its own regulations on logging runoff, Kennedy said the EPA could have reasonably decided that federal regulation would be "duplicative or counterproductive."

In a partial concurrence and dissent, Justice Antonin Scalia mocked Kennedy’s "defensive insistence" that the agency’s interpretation need not be the best one. Scalia said that excluding logging runoff from regulation is "certainly not the most natural" reading of the law. For several years, Scalia has objected to deferring to agency interpretation of its own rules. In Wednesday’s dissent Scalia said, "it is time" to reconsider Auer v. Robbins, a 1997 ruling—which he wrote—codifying that deference.

Significantly, Chief Justice John Roberts Jr. wrote a concurrence acknowledging the debate over Auer and related precedents. But he said the Decker case should not be the vehicle for reassessing the precedents, because the issue was not sufficiently briefed. In a rare reference to the Supreme Court bar, Roberts pointedly added, "The bar is now aware that there is some interest in reconsidering those cases." Justice Samuel Alito Jr. joined Roberts’ concurrence.

Jones Day partner Brian Murray, who filed a brief in the case for a group of law professors, said Roberts’ suggestion that a reconsideration of Auer could be near is "a huge development. It could change the way we think about administrative rulemaking."

Daniel A. Himebaugh, who filed a brief in the case for the Pacific Legal Foundation, applauded the decision. "As a practical matter, a contrary decision would have created crippling and intolerable regulatory burdens for many property owners and small timber-harvesting businesses across the country," Himebaugh said in a statement. "They would have been subjected to an expensive, ambiguous, and lengthy federal permitting process in order to continue making reasonable, productive, traditional use of their land

The Decker case was also notable for the oral argument last December, in which Roberts upbraided a government lawyer for failing to tell the court that a revised regulation on the stormwater runoff issue would be issued just days before the argument took place. The revised rule clarified that no permit was needed, and threatened to make the case moot. "Maybe in the future you could let us know when something as definite as that comes," Roberts told Deputy Solicitor General Malcolm Stewart. "There were 875 pages on the merits briefing in this case, and if we knew that the final rule was imminent, we could have rescheduled the case for April or something along those lines."

Roberts’ pique was not visible in the decision, though Kennedy did deal with the issue of mootness. He said the case was still a live controversy because the timber companies could still be penalized under the old regulation. "The possibility of some remedy for a proven past violation is real and not remote," Kennedy wrote.

Justice Stephen Breyer recused himself in Decker because his brother Charles, a federal district court judge in California, was part of the panel that ruled on the case, on assignment to the Ninth Circuit.

Tony Mauro can be contacted at tmauro@alm.com.