Waiting for Rapanos (and Carabell Too):

Among the many big cases awaiting decision from the Supreme Court are Rapanos v. United States and Carabell v. U.S. Army Corps of Engineers - two companion cases that challenge the scope of federal regulatory jurisdiction under the Clean Water Act (CWA). Argued in February (on Justice Alito's first day), decisions are expected soon. According to some, the future of water pollution control is at risk. Such hyperbole aside -- and it is hyperbole -- these two cases are easily the most important environmental cases of the term and merit close attention. (I previewed both in an NRO column here; the "Rapanos blog" is here.)

The CWA applies to all "navigable waters of the United States" (which the Act defines simply as "waters of the United States"). As interpreted in prior cases, this jurisdiction extends to cover wetlands adjacent to navigable waterways (but does not reach isolated, intrastate waters). At issue in each case is how far the CWA's jurisdiction extends beyond navigable waters and adjacent wetlands, specifically whether the Act applies to wetlands adjacent or hydrologically connected to tributaries of navigable waters. In one case, the wetlands are adjacent to a ditch that drains into a creek that in turn drains into a tributary that is connected to a navigable waterway many miles away. In the other, the wetland is directly adjacent to a tributary, but it is hydrologically separated by a man-made berm.

The federal government argues that jurisdiction under the CWA extends to all wetlands with any hydrological connection to navigable waters, no matter how small or insignificant. "One drop" is enough, according to Solicitor General Paul Clement at oral argument. Rapanos' attorneys at the Pacific Legal Foundation make an equally ambitious argument, that the CWA does not apply past those wetlands truly adjacent to navigable waters -- and that if it did it would press against the limits of the federal government's Commerce Clause power.

Either argument, taken to its fullest extent, would have significant repercussions. Yet the Supreme Court is unlikely to accept either side's case in unadulterated form. While there are four justices who seem willing to adopt the government's position, I doubt they could get a fifth vote without making some concessions. On the other side, I also doubt there are five votes to curtail federal regulations as far as PLF suggests -- particularly since such an amibitious claim is not necessary for either petitioner to prevail on his underlying claim.

In the end, more important than who "wins" this case -- the government or the petitioners -- is how either side wins. In these cases, the devil will be in the details. For instance, the Court could side for the petitioners and remand their cases, yet do so on such narrow terms that they are certain to lose again in the lower courts. The Court could also side for the government largely by deferring to agency expertise without swallowing the heart of the government's argument (and without resolving some of the legal uncertainty that led to these cases in the first place). In other words, how they win is more important than who wins. We'll know soon . . . perhaps as early as today Thursday, when the Court is expected to next issue opinions.

Do Rapanos & Carabell Threaten the Everglades?

A recent article in Scientific American, "The End of the Everglades?" proclaimed that the two wetlands cases before the Supreme Court "jeopardize[] 90 percent of U.S. wetland[]." According to article author Sara Beardsley, the pending decisions "will probably eclipse [the] importance" of current controversies over domestic surveillance and the detention of enemy combatants. I am skeptical, and find SciAm's account misleading on several grounds.

John Rapanos has certainly put a very ambitious argument before the Court. He argues that federal jurisdiction under the Clean Water Act (CWA) extends no farther than truly navigable waters and their adjacent wetlands. Were the Court to accept this argument, it is possible that as much as 90 percent of wetlands in the United States, and a majority of other waters within the nation, would no longer be subject to the CWA. This is a plausible descriptive claim, but an implausible prediction. Few informed observers believe such a holding is a realistic possibility. In other words, the possibility SciAm suggests is something of a "worst case" scenario."

Rapanos and the other petitioner, June Carabell, may well win their cases without the Court adopting Rapanos' theory of CWA jurisdiction in its entirety. There are many intermediate bases upon which the Court could old that the lands in question are sufficiently remote or disconnected from navigable waters and their tributaries to escape federal jurisdiction. Under existing precedent, wetlands and other waters must have a "significant nexus" or otherwise be "inseparably bound up with" navigable waters to be subject to CWA jurisdiction. It would not take much for the Court to find that either or both parcels failed to satisfy this requirement. The Court could also hold that the lower courts applied too permissive a standard and remand for additional consideration. Any of these outcomes is more likely than the drastic reduction in federal jurisdiction postulated by Scientific American. This is especially so given the Roberts Court's demonstrated preference for narrow holdings over broad, sweeping pronouncements. So, as a technical matter, it is true that this case could result in the removal of federal protection for the vast majority of wetlands, but this is quite improbable.

The SciAm is also misleading because it equates the reduction of federal regulatory jurisdiction under the CWA with the elimination of environmental protection. This would be a non-controversial claim were federal regulation the only means of protecting wetlands (and if such regulation were clearly effective). But this is not the case. As the article notes in passing, "only half" of state have wetland programs. But this means that some amount of wetland protection would remain in at least half of the states. More importantly, a reduction in federal regulation would almost certainly result in an increase in wetland protection efforts.

After the Supreme Court held in 2001 (in Solid Waste Agency of Northern Cook County v. U.S. Army Corps of Engineers, aka "SWANCC") that the CWA does not apply to truly isolated waters, several states adopted new statutes or regulations to expand the scope of their protections so as to make up some of the gap. Many other states already had rules on the books covering isolated wetlands, so additional action was unnecessary. Still others considered adopting new rules, and may yet still. As I have documented elsewhere (see, e.g., here and here), states have been more active at wetland protection than many realize. The regulatory uncertainty produced by the SWANCC decision most likely discoraged some states from acting that otherwise would have expanded their wetland protection efforts. As I argue in this draft paper, federal regulation likely has a greater "crowding out" effect on state efforts than is conventionally recognized.

The point here is not that states will completely fill any regulatory gap created by judicial limitations on the scope of CWA jurisdiction. The net result of a victory for the petitioners will be a reduction in wetland regulation, at least in the short run. Nevertheless, state efforts -- both those preexisting and subsequent to any decision -- must be taken into account when assessing the actual environmental effect of the Court's decision. This is particularly important because there are reasons to expect that states, in the aggregate, will be more active regulators if federal jurisdiction is limited than they are today. Other factors that must also be considered are the extent to which existing non-regulatory efforts -- both public and private -- protect certain types of wetlands in certain types of the country, as these programs will not be influenced by the Court's ruling.

Here is the bottom line: Even if the Supreme Court were to rule this month that 90 percent of wetlands are no longer regulated by the Clean Water Act, this would not mean that 90 percent of wetlands are now unprotected or otherwise "jeopardized". While there are many threats to the Everglades, the pending Rapanos and Carabell decisions should not be counted among them.

UPDATE: I thought it went without saying that there are additional reasons why the Everglades, in particular, would not be threatened by a reduction in Clean Water Act jurisdiction. As noted in the comments, much of the Everglades would remain protected even under an exceedingly narrow interpretation of the law. Substantial portions of the Everglades qualify as wetlands adjacent to navigable waters. Moreover, a ruling on CWA jurisdiction would not affect the protection afforded those portions of the Everglades owned or managed by government entities at the federal or state level. I drew the title of the post from that of the article, but sought to focus on the SciAm story's broader suggestion that a victory for Rapanos and Carabell would necessarily result in a dramatic reduction in federal regulatory jurisdiction or environmental protection.

Rapanos, Wetlands & State Regulation:

A commenter on my last Rapanos-related post feels that I did not respond adequately to the concern that state efforts will be inadquate were the Supreme Court to narrow the scope of federal wetland regulation in Rapanos and Carabell. In this follow-up post, I will try to address this issue in greater detail (and point readers to articles in which I make some of these arguments in greater detail).

First, the fact that "only half" of states have wetland programs does not provide evidence that states would not protect wetlands in the absence of federal action. In fact, given the history of wetland regulation, I believe it suggests the opposite. State regulation of wetlands began in 1963, when Massachusetts adopted the first state wetland protection statute (which was itself modeled on preexisting local wetland protections). At this time, the federal government was not protecting wetlands. To the contrary, it was still subsidizing their destruction through various federal programs.

By the time the federal government got around to regulating the filling of wetlands in 1975, every coastal state save Texas had a wetland protection statutes on the books, and eleven states had freshwater wetland protection programs. The federal government did not lead the way in protecting wetlands. It was dragged along behind the states. Indeed, the U.S. Army Corps of Engineers only began regulating wetlands after it was told to by a federal court. [I recount this history in some detail in my article "Wetlands, Waterfowl and the Menace of Mr. Wilson, 29 Env. L. 1 (1999).]

Second, it is alleged that states are unlikely to protect wetlands because "there are pressures in local communities for land development that keep [state and local] guidelines from being as rigorous." Relatedly, some contend that the pressure to compete with other states for economic development will discourage states from adopting costly environmental measures. This "race to the bottom" argument is familiar, but it is also undermined by the empirical evidence. The pattern of state regulation prior to federal involvement is the exact opposite of what the RTB theory would predict. Those states with the most wetlands, measured as a percentage of their land area, should have been the least likely to regulate. Yet they regulated first. Indeed, every state in the continental U.S. with more than ten percent of its land area classified as wetlands regulated prior to 1975. Moreover, many states contain wetland protections that are more extensive, expensive, and ecologically minded than the federal program. [I have more to say about the alleged RTB here, as well as in the article cited above.]

The available evidence is even more suggestive when one realizes that the incentive for states to adopt their own wetland protections dropped dramatically once the federal government got into the act. In simple economic terms, the net benefits of adopting such programs declined to the extent that federal regulation served as a substitute for state regulations. Even those states that, today, demand greater levels of wetland protection than the federal government provides may be discouraged from adopting new programs by the existence of the federal regulations. [I have much more to say on this potential "crowding out" effect of federal regulation in this draft paper on SSRN.]

No one can say for certain what states (and local governments and non-governmental conservation groups) would do were the federal government's regulatory authority limited by the Court, but I do believe the evidence suggests that states, on the whole, would be significantly more active than they are today. As I noted in my last post, after the Supreme Court's 2001 SWANCC decision, it appeared that the federal government's CWA jurisdiction would limited substantially. In this period, numerous states began to consider new measures to fill the gap. In some states, such as Ohio, these measures were adopted. Within short order, however, it became clear that both the federal government and most lower courts would read SWANCC narrowly, so the need for greater state efforts was less clear. Nonetheless, when it looked like greater state action was necessary, states appeared ready to respond (even if they would have preferred action at the federal level).

All of this does not mean that a curtailment of federal regulation will have no effect on wetland protection. But I believe it does show that the actual reduction in actual wetland protection caused by limitations on federal jurisdiction will be less than many fear. If greater attention were paid to the interrelationship between federal and state regulation, and more focus were placed on encouraging state-level, as well as localized and non-governmental wetland protection efforts, we could achieve greater levels of environmental protection at lower economic and social cost. There are many reasons to be dissatisfied with federal regulation, not least its poor record at delivering the environmental goods. If Rapanos and Carabell such regulation, I hope they will spur new efforts to consider possible alternatives.

In the end, it is important to look at the broader context. I would be the last person to claim that state regulation is perfect. But federal regulation is far from ideal as well. Indeed, I could cite dozens of environmental analysts lamenting the inadequacy of federal wetlands regulations -- the same regulations that some seem to suggest are the only things preventing utter ecological devastation. The relevant question is not whether a given balance of state and federal authority produces the desired level of environmental protection -- for many of us, that is unlikely to ever be the case -- but which institutional arrangement maximizes the combination of environmental protection and other values that are important to us. So, the relevant question is not "will [states/feds/others] do a good job," but which is best (or, perhaps, least worst).

Post-Script: One point I did not address is the concern about interstate pollution. In this context it is largely a red herring. Federal wetland regulation has little to do with the control of interstate pollution spillovers. And while a decision limiting this program will have some effect on other parts of the CWA, it need not have much (if any) effect on federal efforts to control interstate water pollution. If there is interest, I can explain in greater detail in a subsequent post.

Rapanos & Carabell Decided:

SCOTUSBlog reports that a divided Supreme Court held this morning that Clean Water Act is limited. Justice Scalia wrote a plurality, with Justice Kennedy concurring (and providing the fifth vote). It appears to be a signficiant win for the petitioners, but the key will be how much Kennedy's opinion modifies Scalia's plurality. More to follow once I've read and digested the opinions.

UPDATE: From the Associated Press:

The Supreme Court ruled 5-4 Monday that regulators may have misinterpreted the federal Clean Water Act in refusing to allow two Michigan property owners to build a shopping mall and condos on wetlands they own. At the same time, justices could not reach a consensus on whether government wetlands protections extend miles away from waterways. . . .

The court voided rulings against June Carabell and John Rapanos, who wanted to fill their wetlands near Lake St. Clair in Macomb County. Carabell wanted to build condos on wetlands she owns about a mile from the lake. Rapanos wanted to put a shopping mall on his property, which is about 20 miles from the lake.

Instead of ruling in the property owners' favor, as they requested, justices said lower courts must reconsider whether ditches and drains near wetlands are waters.

UPDATE: The opinions are now available here.

Initial Thoughts on Rapanos:

In both Rapanos and Carabell, the petitioners obtained the remand of their cases, as they wanted, but should they be happy? Time will tell, but on my initial read it seems that the petitioners may have won the battle only to lose the war.

Justice Scalia offered a plurality opinion that would significantly narrow the application of Section 404 of the Clean Water Act (CWA) to private lands. Under his view, only wetlands actually "adjacent" (defined as "possessing a continuous surface water connection") to actual "waters of the United States" (defined as "continuously present, fixed bodies of water" or streams with "a relatively permanent flow") could be regulated as "waters" under the CWA. However appealing Scalia's opinion may be as a matter of textual interpretation, it is in tension with the Court's prior precedents and could not command a majority of the Court.

Justice Kennedy's opinion provided the fifth vote for a remand to the lower courts. This would seem to be a victory for the petitioners. Yet his opinion provides ample opportunity for the federal government to demonstrate jurisdiction over the relevant parcels. Indeed, the closing portion of his opinion provides a formula for how this could be achieved. If lower courts were reluctant to give the Supreme Court's SWANCC opinion much teeth, Justice Kennedy's opinion virtually assures a similar application of Rapanos.

Yet the Kennedy opinion is not a sweeping victory for the government. Just as Kennedy rejects the narrow reading offered by Justice Scalia, he equally rejects the anything-the-Corps-wants-the Corps-gets approach encouraged by the dissent. Relying on SWANCC, Justice Kennedy reiterates that "the Corps' jurisdiction over wetlands depends upon the existence of a significant nexus between the wetlands in question and navigable waters in the traditional sense." Yet where the SWANCC majority understood that a "significant nexus" required regulated parcels to to be "inseparably bound up with the 'waters' of the United States" (quoting Riverside Bayview Homes), Justice Kennedy would require the nexus to "be assessed in terms of the statute's goals and purposes."

In the near term, Justice Kennedy's concurring opinion creates more work for federal regulators. His concurrence presumes that the U.S. Army Corps of Engineers will draft and promulgate additional regulations that identify what creates a "significant nexus" between wetlands and waters. In subsequent enforcement actions and challenges to federal jurisdiction, federal officials will also have to make a greater showing that a given parcel has the requisite ecological attributes to meet this test. But without a dramatic shift in the approach adopted by most federal courts, this is a burden the federal government will meet more often than not, particularly since most federal courts will readily defer to the Corps' technical expertise.

It is also worth noting that the Court's actual opinions show unreasonably apocalyptic were some characterizations of the stakes in these cases (e.g. that the Everglades could be at stake as Scientific American suggested). The arguments advanced by petitioner Rapanos were so sweeping and ambitious that they commanded not a single vote on the Court. Even Justice Scalia's plurality explicitly rejected so narrow a reading of federal jurisdiction. Considerations of stare decisis have particular force in the statutory context. Thus, even were a majority of justices sympathetic to such an interpretation of the Act, it was foreclosed by the Court's prior interpretations.

Finally, I would note that the Corps has long been on notice that its wetland regulations exceeded the permissible scope of federal CWA jurisdiction. Yet for years it has refused to do anything about it. After a slim Court majority revived Commerce Clause limits on federal authority in United States v. Lopez, many observers identified the Corps' regulations as among the most vulnerable in the C.F.R., but the Corps looked the other way. Several years later, in SWANCC, a similarly slim majority struck down the "Migratory Bird Rule" on the grounds it exceeded the permissible scope of the statute and pushed against constitutional limits on federal power. Again the Corps failed to revise its rules.

As Chief Justice Roberts noted in his concurrence, the Bush Administration briefly considered revising the applicable rules so as to clarify their scope and ensure their compliance with applicable precedent, but this effort was soon scuttled.

Rather than refining its view of its authority in light of our decision in SWANCC, and providing guidance meriting deference under our generous standards, the Corps chose to adhere to its essentially boundless view of the scope of its power. The upshot today is another defeat for the agency.
I am not sure today's decision is a true "loss" for the agency in the long run, but the Chief Justice's point should be well taken. Had the Corps revised its regulations after Lopez or SWANCC, the outcome in Rapanos might have been different. Courts give agencies substantial leeway to define the scope of their activities, particularly in technical areas such as environmental regulation. Agencies that heed judicial warnings and take limiting decisions seriously will fare better in the future than those that look the other way.

[Cross-posted at SCOTUSBlog]

More Perspectives on Rapanos:

SCOTUSBlog is running a discussion board on today's Rapanos decision. Up so far are comments from Georgetown's Richard Lazarus, Emory's William Buzbee, and Chapman's John Eastman. More to follow.

The folks from the Pacific Legal Foundation, who represented Rapanos, are also busy with their reaction and analysis on the Rapanos blog.

Preliminary Thoughts on Rapanos and Federalism - Much Ado About Very Little:

Some observers hoped and others feared that the Rapanos case might rein in the virtually limitless theory of federal regulatory power that the Supreme Court embraced last year in Gonzales v. Raich. My preliminary reading of the Rapanos opinions suggests that such hopes and fears have turned out to be groundless. The Rapanos majority does not impose any constitutional limits on federal power. Nor does it increase protection for federalism provided by rules of statutory interpretation.

In Raich, the Court held that Congress' Commerc Clause power to regulate "Commerce . . . Among the several States" was broad enough to allow it to criminalize the possession of homegrown marijuana used for noncommercial medical purposes. For a good explanation of why the reasoning of Raich gives Congress virtually unlimited regulatory power (constrained only by constitutionally protected individual rights, but not by any notion of limited powers), see this article by co-blogger Jonathan Adler.

Rapanos does not Impose any Constitutional Limits on Federal Power.

Rapanos leaves the holding of Raich unchanged. Neither Justice Scalia in his plurality opinion nor Justice Kennedy addresses the constitutional issues raised by the property owners. Both rely exclusively on statutory interpretation arguments about the meaning of the Clean Water Act (CWA). They hold that Congress in the CWA DIDN'T give the Army Corps of Engineers the power to regulate any and all bodies of water, no matter how small or non-navigable. But that does not mean that it COULDN'T do so if it wanted to. Indeed, it is striking that Scalia's opinion does not even mention Raich, while Kennedy's does so only briefly, using it to justify interpreting the CWA to give the Corps greater regulatory authority than the plurality would allow.

Rapanos, Federalism, and Clear Statement Rules.

Rapanos also does little or nothing to limit congressional power through rules of statutory interpretation. There are two rules of construction by which the Rapanos majority could have constrained congressional power. The so-called "constitutional avoidance" canon requires courts to reject interpretations of a statute that "raise serious constitutional problems" unless there is a clear statement in the law that Congress intended it to be interpreted in that way. See, e.g., Edward J. DeBartolo Corp. v. Florida Gulf Coast Bldg. & Const. Trades Council, 485 U.S. 568, 574 (1988); NLRB v. Catholic Bishop of Chicago, 440 U.S. 490, 504 (1979) (requiring a "clear expression of an affirmative intention of Congress" before a statutory interpretation that raises serious constitutional questions can be accepted). The "federalism canon" requires a similar "unmistakably clear" statement of Congressional intent in statutes that "alter the usual constitutional balance between the States and the Federal Government." Gregory v. Ashcroft, 501 U.S. 452, 460 (1991). In the 2001 SWANCC case, the Court relied on both canons in rejecting the Army Corps of Engineers' "migratory bird rule," which interpreted the CWA to give the Corps authority to regulate any isolated non-navigable waters that might be used by migratory birds.

Justice Scalia's plurality opinion briefly cites the two canons to buttress its interpretation of the CWA. However, Scalia mostly relies on a detailed textual analysis of the statute. His opinion does not hold that either canon would require rejection of the government's interpretation of the CWA even if the latter were otherwise persuasive. This is a significant omission, since previous avoidance canon cases specifically note that clear statement rules require courts to reject even "an otherwise acceptable construction of a statute" if endorsing it "would raise serious constitutional problems." DeBartolo, 485 U.S. at 574.

In any event, Scalia's treatment of the canons probably lacks precedential signifance and does not bind lower courts because Justice Kennedy specifically rejected it in his concurring opinion. Because Rapanos is a 5-4 decision, Kennedy's vote was decisive to the result. As Justice Roberts (who signed onto Scalia's interpretation of the CWA) points out in his concurring opinion, cases where there is no one opinion endorsed by a majority of the Court are governed by Marks v. United States, 430 U.S. 188 (1977). According to Marks:

When a fragmented Court decides a case and no single rationale explaining the result enjoys the assent of five justices, the holding of the Court may be viewed as that position taken by those Members who concurred in the judgments on the narrowest grounds. Marks v. United States, 430 U.S. at 193.

In this case, Kennedy is almost certainly the justice who concurred on the "narrowest grounds," since his opinion places fewer restrictions on the Corps than Scalia's, and also provides a considerably less sweeping and more ambiguous interpretation of the CWA. Thus, Rapanos is unlikely to expand the application of the two avoidance canons to statutes that rely on Congress' Commerce Clause authority.

Perhaps even more importantly, both Kennedy and Scalia fail to consider the broader implications of Raich for the two clear statement canons. If Raich is correct and congressional Commerce Clause power is essentially unlimited, a statute that relies on a broad interpration of that power cannot "raise serious constitutional problems." There is no "problem" because there are no constitutional limits for Congress to infringe. Similarly it becomes almost impossible for Congress to write a statute that "alter[s] the usual constitutional balance between the States and the Federal Government." Under Raich, the "usual constitutional balance" is one where there are no structural limits to congressional authority. The only "usual constitutional balance" that can exist is whatever Congress decides on. Interestingly, the Court also failed to consider the impact of Raich on the two clear statement statement rules in this year's other federalism/statutory interpretation decision, Gonzales v. Oregon.

Some scholars, such as Columbia's Tom Merrill, have proposed a new rule under which courts could impose a federalism clear statement requirement even if there is no doubt that Congress has the constitutional power to regulate the activity in question. The Rapanos decision, however, does not endorse this approach or even mention it.

The implications of Raich for the two clear statement rules will have to be explored in some future case. For now, the post-Raich status quo remains essentially unchanged.

UPDATE: Georgetown professor Richard Lazarus also agrees that Kennedy's opinion will be the controlling one under Marks.

Scalia v. Roberts on Agency Deference in Rapanos:

Some commentators have zeroed in on a potential tension between Justice Scalia's plurality opinion and Chief Justice Roberts' separate concurring opinion in Rapanos over the issue of judicial deference to an agency's statutory interpretation. This tension is interesting both because the Chief Justice joined Scalia's opinion, and because it may tell us something about how the Roberts Court will approach future agency interpretations of regulatory statutes, both in the wetlands context as well as in future cases.

Justice Scalia's opinion adopts a particular interpretation of the meaning of "waters" in the Clean Water Act. Further, as the Cato Institute's Mark Moller observes, Scalia's opinion stresses "that before an agency can reach local conduct under a comprehensive regulatory program, Congress must clearly authorize it to do so in the statutory text." Chief Justice Roberts, on the other hand, suggests that the statute is sufficiently ambiguous for the Army Corps of Engineers to "enjoy[] plenty of room to operate in developing some notion of an outer bound to the reach of their authority." Justice Scalia seems to know what the CWA means, and devotes much of his opinion to analyzing the relevant statutory text, whereas the Chief finds it fairly ambiguous. Are these two opinions really in conflict? I am not so sure.

Despite Justice Scalia's focus on the text of the statute, his opinion avoids claiming that the precise scope of CWA jurisdiction is clear, and that no deference is due to the Corps of Engineers. To the contrary, his opinion notes that that "'waters of the United States' is in some respects ambiguous," and acknowledges that there is some "ambiguity" as to where land ends and water begins. All that is clear, according to the plurality, is that "the Corps' expansive interpretation of 'the waters of the United States' is . . . not 'based on a permissible construction of the statute.'"

While portions of the opinion appear to be offering an authoritative interpretation of the term "waters" in the CWA, that is not what the opinion does. In administrative law terms, Scalia's opinion rejects the Corps of Engineers' interpretation at step two rather than step one of the familiar Chevron analysis. Indeed, Scalia quotes the step two test -- whether the agency has adopted a "permissible construction" of ambiguous statutory text - in rejecting the Corps' position.

I believe this reading of the plurality opinion eases the apparent tension between it and the Chief's concurrence. It also suggests that the federal government would retain substantial ability to go back and define "waters of the United States" in fairly expansive terms, even if it could not rely upon a fifth vote from Justice Kennedy for a broad interpretation of the Act.

Commenting on Chief Justice Roberts' concurring opinion, Moller offers the following interpretation:

If the agency deliberates about its constitutional and statutory authority in a "limiting way" in the context of public notice and comment procedures, he would give the agency "generous" deference, even [if]the EPA would draw lines different (and more expansive) than those that Scalia's plurality opinion draws.
I would agree. My point is that nothing in Justice Scalia's opinion necessarily contradicts this view. While I have little doubt that Justice Scalia would continue to read the CWA quite narrowly, his opinion offers the relevant agencies more wiggle room that it might at first appear.

NOTE: I offer some additional thoughts on the Rapanos opinion in this NRO column .