On the merits, the Supreme Court held that EPA's rules exempt "discharges of channeled stormwater runoff from logging roads from the NPDES permitting scheme." Slip Op. at 15. The Court reasoned that EPA's reading of its regulations was reasonable, was longstanding, and complied with the intent of the Clean Water Act:
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. When an agency interprets its own regulation, the Court, as a general rule, defers to it “unless that interpretation is ‘plainly erroneous or inconsistent with the regulation.’” Chase Bank USA, N. A. v. McCoy, 562 U. S. _, _ (2011) (slip op., at 12) (quoting Auer, 519 U. S., at 461). The EPA’s interpretation is a permissible one. Taken together, the regulation’s references to “facilities,” “establishments,” “manufacturing,” “processing,” and an “industrial plant” leave open the rational interpretation that the regulation extends only to traditional industrial buildings such as factories and associated sites, as well as other relatively fixed facilities associated sites, as well as other relatively fixed facilities.
There is another reason to accord Auer deference to the EPA’s interpretation: there is no indication that its current view is a change from prior practice or a post hoc justification adopted in response to litigation. See Christopher v. SmithKline Beecham Corp., 567 U. S. ___, ___ (2012) (slip op., at 10). The opposite is the case. The agency has been consistent in its view that the types of discharges at issue here do not require NPDES permits.
The EPA’s decision exists against a background of state regulation with respect to stormwater runoff from logging roads. The State of Oregon has made an extensive effort to develop a comprehensive set of best practices to manage stormwater runoff from logging roads. These practices include rules mandating filtration of stormwater runoff before it enters rivers and streams, Ore. Admin. Rule 629–625–0330(4) (2012); requiring logging companies to construct roads using surfacing that minimizes the sediment in runoff, Rule 629–625–0700(2); and obligating firms to cease operations where such efforts fail to prevent visible increases in water turbidity, Rule 629–625–0700(3). Oregon has invested substantial time and money in establishing these practices. In addition, the development, siting, maintenance, and regulation of roads—and in particular of state forest roads—are areas in which Oregon has considerable expertise. In exercising the broad discretion the Clean Water Act gives the EPA in the realm of stormwater runoff, the agency could reasonably have concluded that further federal regulation in this area would be duplicative or counterproductive. Indeed, Congress has given express instructions to the EPA to work “in consultation with State and local officials” to alleviate stormwater pollution by developing the precise kind of best management practices Oregon has established here. 33 U. S. C. §1342(p)(6).Slip Op. at 14-15. The Court's resolution of this issue seems to still leave the Ninth Circuit litigation on the EPA's new rule in play. I'll continue following that issue.
The second broader implication, as the New York Times notes, is Justice Scalia's call for review in his dissent of the longstanding principle of administrative law that executives agencies receive great deference to agency interpretations of their own regulations:
The Court gives effect to a reading of EPA’s regulations that is not the most natural one, simply because EPA says that it believes the unnatural reading is right. It does this, moreover, even though the agency has vividly illustrated that it can write a rule saying precisely what it means—by doing just that while these cases were being briefed. Enough is enough.Justice Scalia forcefully argues that, while there may be reasons to defer to an agency's interpretation to a statute where Congress has purposefully delegated authority to the agency, there is no good reason to do the same for an agency when it interprets its own rule. "For decades, and for no good reason, we have been giving agencies the authority to say what their rules mean, under the harmless-sounding banner of “defer[ring] to an agency’s interpretation of its own regulations.” Ultimately, he says, "He who writes a law must not adjudge its violation."
This idea seems quite reasonable to me, just as it did to Chief Justice Roberts and Justice Alito. They, however, recognized the argument goes "to the heart of administrative law." Accordingly, while they expressed some interest in reconsidering this principle, they felt this case was not the proper vehicle for the argument because it had not been argued in any depth. At the very least, Justice Scalia's dissent should give rise to some interesting petitions for certiorari to the Supreme Court in the coming days.