This post is part of the Environmental Law Review Syndicate.
On January 31, 2018, the U.S. Environmental Protection Agency (“EPA”) and U.S. Army Corps of Engineers (“Corps”) finalized a rule delaying implementation of the Obama-era Clean Water Rule until February, 2020. The Clean Water Rule had attempted to clarify the definition of “waters of the United States” and the boundaries of federal jurisdiction under the Clean Water Act (“CWA”). Now, with implementation of the Clean Water Rule delayed, we return to a world where federal jurisdiction under the CWA is governed by the Supreme Court’s fractured opinion in Rapanos v. United States.
This article will briefly review the Clean Water Act and previous Supreme Court opinions that led to Rapanos, discuss the Court’s Rapanos opinions, examine how Marks v. United States defined the “narrowest grounds,” provide an overview of the various lower court’s interpretations of Rapanos as they have attempted to apply Marks, and finally consider options going forward.
To understand the problems posed by Rapanos and some of the challenges the lower courts have faced in parsing the opinion, it is necessary to have a basic understanding of the Clean Water Act and the Supreme Court’s opinions prior to Rapanos.
Congress passed CWA for the purpose to “restore and maintain the chemical, physical, and biological integrity of the Nation's waters.” Two of the ways the Act sought to achieve its lofty goal was to prohibit the discharge of any “pollutants” or “dredged or fill material” to “navigable waters” without a permit. The term “navigable waters” was traditionally defined as navigable-in-fact waterways that could be used as a channel of interstate commerce. However, Congress, recognizing a broader definition was needed to achieve the goals of the act, expanded “navigable waters” to “waters of the United States, including the territorial seas,” without defining “waters of the United States.” This vague definition of “navigable waters” started the flow of litigation leading to Rapanos.
The first Supreme Court case to consider the definition of “navigable waters” was United States v. Riverside Bayview Homes in 1985. In Riverside, the Court held that the Corps did not act unreasonably in interpreting “navigable waters” to include non-navigable wetlands that were adjacent or connected to navigable-in-fact waters. This decision seemed to support deference to the agency, in making what can be a complicated scientific decision, and a broad definition of “navigable waters.” In 2001, however, the Court held that the agency went beyond its jurisdictional authority in Solid Waste Agency of Northern Cook County v. Army Corps of Engineers (“SWANCC”). Prior to SWANCC the Corps and EPA had promulgated the Migratory Bird Rule, which extended the Corps’ jurisdiction under the CWA to include intrastate waters and wetlands that were not connected to traditionally navigable waters so long as they were used by migratory birds. The Court, after reviewing the statutory language, struck down the Migratory Bird Rule as beyond the scope of the Act and held that for a wetland to be within the Corps’ jurisdiction it must be adjacent to a navigable water. While the Court recognized that Congress intended to regulate beyond navigable-in-fact waters, it narrowed the Corps’ authority and set what, until Rapanos, was the outer bound of the Corps’ jurisdiction. Despite SWANCC lower courts continued to take a broad reading of “navigable water.”
III. The Rapanos Decision
The preceding history, and the lower courts’ broad reading of “navigable waters,” set the stage for Rapanos. In Rapanos, the Court addressed whether the terms “navigable waters” and “waters of the United States” in the CWA covered wetlands which were not navigable themselves and which were not adjacent to waters that were navigable. Rather, the waters at issue were connected to man-made ditches and drains that eventually emptied into traditionally navigable waters.
Justice Scalia wrote for the plurality, joined by Chief Justice Roberts and Justices Alito and Thomas (hereinafter “the Plurality”). The Plurality found that the Corps’ interpretation of “navigable waters” exceeded the scope of the CWA. The Plurality first narrowed the definition of the phrase “waters of the United States,” with regard to tributaries, such that it
includes only those relatively permanent, standing or continuously flowing bodies of water “forming geographic features” that are described in ordinary parlance as “streams[,] . . . oceans, rivers [and] lakes.” The phrase does not include channels, through which water flows intermittently or ephemerally, or channels that periodically provide drainage for rainfall.
It is important to note the emphasis on the relative permanency of flow and the geographic features of the waters. The Plurality dropped a footnote to clarify that by “relatively permanent” they did not mean to exclude waters that might dry up in extraordinary circumstances or seasonal rivers which contain flow only during some months. These features of the Plurality’s opinion have become important as lower courts have struggled to apply the law to geology and hydrology.
The second part of the Plurality opinion addressed wetlands, stating that “only those wetlands with a continuous surface connection to bodies that are ‘waters of the United States’ in their own right, so that there is no clear demarcation between ‘waters’ and wetlands, are ‘adjacent to’ such waters and covered by the Act.” The opinion explained that “[w]etlands with only an intermittent, physically remote hydrologic connection to ‘waters of the United States’. . . lack the necessary connection” to be jurisdictional. This continuous surface connection test represents the Plurality’s focus on physical features to define “waters of the United States.”
In support of this test, the Plurality also spent some time discussing Congress’ use of the term “navigable” in relation to defining the scope of CWA jurisdiction. Reasoning that Congress must have meant something by using “the traditional phrase ‘navigable waters,’” the Plurality attempted to give it some effect in their interpretation of “waters of the United States.”
Justice Kennedy concurred in the judgment, agreeing that the Corps had exceeded their jurisdiction, but differed from the Plurality in how to define “waters of the United States.” His opinion limited the Corps’ jurisdiction to those wetlands that have a “significant nexus” to “navigable waters in the traditional sense.” To have a significant nexus a wetland must “either alone or in combination with similarly situated lands in the region, significantly affect the chemical, physical, and biological integrity” of traditionally navigable waters. Conversely, if a “wetlands’ effects on water quality are speculative or insubstantial” it would not be jurisdictional. Justice Kennedy’s test takes a much more ecological approach than the Plurality. This is in part a recognition that Congress’ purpose in passing the act was to restore the ecological health of the Nation’s waterways. The one point where Justice Kennedy and the Plurality agreed was that wetlands that are adjacent to traditionally navigable waters are “waters of the United States.”
Justice Stevens’ dissent, joined by Justices Souter, Ginsburg, and Breyer (hereinafter “the Dissent”), would have granted Chevron deference to the Corps’ interpretation of “navigable waters” and upheld the lower court’s rulings. Recognizing the problems created by the lack of a controlling majority the Dissent pointed out that the Plurality and Justice Kennedy’s concurrence “define different tests to be applied on remand.” The Dissent then went on to advise lower courts that all four justices of the Dissent would uphold the Corps’ jurisdiction under either the Plurality’s or Justice Kennedy’s test, and that “on remand each of the judgments should be reinstated if either of those tests is met.” Justice Stevens recognized that there was not going to be an easily determined “narrowest grounds,” or overlapping directive, between the two opinions. While Justice Kennedy’s concurrence gives the Corps more jurisdiction than the Plurality’s opinion, there is the potential for a wetland to have a continuous surface flow, meeting the Plurality’s test, but not a significant nexus, failing Justice Kennedy’s test.
Chief Justice Roberts also recognized the problems posed by the lack of a controlling opinion and wrote separately to provide guidance to the lower courts. The Chief Justice lamented that “[l]ower courts and regulated entities will now have to feel their way on a case-by-case basis.” The Chief Justice then went on to cite Grutter v. Bollinger for its discussion of Marks. Some have suggested that pointing to the discussion of Marks in Grutter was meant to show lower courts that there was precedent on how to interpret plurality opinions, and that lower courts should apply the Marks doctrine to the fractured Rapanos opinion. However, the actual approach taken by the Court in Grutter, not “[pursuing] the Marks inquiry to the utmost logical possibility,” is much closer, in reality, to the lower courts’ varying treatment of the Rapanos opinion. The message the Chief Justice meant to send with his citation to Grutter as opposed to citing directly to Marks is unknown, but it was prescient.
IV. Finding Meaning in Marks - What are the Narrowest Grounds?
In Marks v. United States, the Court stated that 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.’” In the case of Marks, the Court held that the narrowest grounds from the prior opinion in Memoirs v. Massachusetts was the plurality’s opinion that “materials were deemed to be constitutionally protected unless. . . they were ‘utterly without redeeming social value,’ and satisfied the. . . other requirements.”
The “narrowest grounds” quote from Marks was derived from a footnote in Gregg v. Georgia, where the Court considered whether the death penalty, as applied, was cruel and unusual punishment and interpreted the fractured opinion of Furman v. Georgia. In Gregg, the Court determined that the narrowest grounds articulated in Furman was that of the two concurring judges who found the death penalty as applied cruel and unusual, but did not find the death penalty per se cruel and unusual. The Gregg Court held that “Furman mandates that where discretion is afforded a sentencing body [on the death penalty], that discretion must be suitably directed and limited so as to minimize the risk of wholly arbitrary and capricious action.”
The Court in both Marks and Gregg, therefore, recognized that despite the lack of controlling majority, Memoirs and Furman yielded controlling law. In both cases the Court spent little time discussing how exactly to define the narrowest grounds, instead identifying the opinions that constituted the “governing standard.”
Where fractured plurality opinions directly overlap, and one opinion is a logical subset of the other(s), finding such a standard may be fairly straight-forward. However, when the fractured opinions are based on divergent reasoning, and thus are not logical subsets of each other, applying the “narrowest grounds” inquiry gets much more complicated. Indeed, as one court has observed “[f]or some issues, asking which of two opinions is narrower is akin to asking, ‘Which is taller, left or right?’” With this in mind, it is useful to examine the various ways in which the Memoirs plurality and the Furman concurrence may constitute the narrowest grounds.
The first approach is the implicit consensus approach, where the opinion that is found to be the “governing standard” is a logical subset of the other opinions. In Memoirs the plurality was a logical subset of the other concurrences in that it arrived at the same outcome but was not as restrictive for future cases as the concurrences. One way to think about this approach is as a “middle-ground opinion,” which falls between the broadest opinion supporting the judgment and the dissent. In other words, the opinion constituting the narrowest grounds would “apply in a subset of cases encompassed by the broader opinion.” This was true for the Gregg Court’s determination that the Furman concurrence constituted the narrowest grounds.
However, when the opinions are not logical subsets of each other, then the implicit consensus approach falls apart. In such cases, another option is the “fifth-vote approach,” which defines the narrowest grounds as the opinion that would enjoy the support of the most judges should they be forced to choose. Marks suggested that the “narrowest grounds” must be found from those judges concurring in the judgment, implying that the dissent should not be considered. However, some courts have determined that the dissent may be included in this calculation. Indeed, this is what Justice Stevens counseled in his Rapanos dissent by noting that the four dissenting justices would find jurisdiction under either the Plurality’s test or Justice Kennedy’s test. However, courts have been hesitant to employ this approach.
Another way to view the Marks and Gregg analysis is that the “least far-reaching” approach constitutes the “narrowest grounds.” In the case of Marks this could be either the opinion least restrictive of the government’s ability to police obscene material, or the opinion which changes the status quo the least. In the case of Gregg the “least far-reaching” might mean the opinion that changes the status quo the least, or is the least restrictive of the government’s ability to use the death penalty. In either case, however, it is hard to see how these rationalizations might be described as the “narrowest” except that they make the narrowest change to existing law.
Finally, Professor Ryan Williams advances the “issue-by-issue” approach to finding the “narrowest grounds,” where the lower court looks to fractured opinions (including the dissent) to “determine each proposition where five or more justices agree.” Several courts have taken this approach in parsing Rapanos, demonstrating what has become clear from lower courts’ attempts to find meaning in Rapanos: the clearest guidance may have been that of Chief Justice Roberts’ concurrence, telling courts “to feel their way on a case-by-case basis.”
V. Lower Courts Tackle Rapanos
To date the Rapanos opinion has been cited in over ninety cases in at least thirty-five states. Six circuit courts have attempted to apply the fractured opinion with varying results. The first appellate court to consider the Rapanos opinion was the Seventh Circuit in United States v. Gerke Excavating. The Supreme Court had remanded Gerke to the Seventh Circuit with express instructions to reconsider the decision in light of Rapanos. Applying Marks, the Gerke court determined that Justice Kennedy’s concurrence constituted the narrower test because it was less restrictive of federal authority. The Gerke court reasoned that where Justice Kennedy found jurisdiction so would the four Rapanos dissenters. In reaching its decision, the court did recognize that in some cases the Rapanos plurality would find jurisdiction where Justice Kennedy would not and that the four dissenters would join the Plurality in those rare cases, but found that as a “practical matter the Kennedy concurrence was the least common denominator.”
The Ninth Circuit and Eleventh Circuit arrived at similar conclusions as the Seventh Circuit, determining that Justice Kennedy’s test constituted the narrowest grounds. Even though these three circuit courts arrived at the same conclusion, they got there by very different reasoning. The Seventh Circuit and Ninth Circuit both employed an issue-by-issue approach in determining that a majority of the justices, including the dissenters, would most often find CWA jurisdiction under Justice Kennedy’s test. In contrast, and despite also holding that Justice Kennedy’s approach was the narrowest, the Eleventh Circuit explicitly rejected the issue-by-issue approach, instead determining that Marks prevented it from considering the dissent when determining the narrowest grounds.
The next circuit court to consider Rapanos after the Seventh Circuit was the First Circuit in United States v. Johnson. After an extensive analysis of Marks and subsequent decisions analyzing Marks, the Johnson court noted that the Supreme Court had “moved away from Marks” and determined that neither the Plurality nor Justice Kennedy’s concurrence constituted the “narrowest grounds.” The Johnson court decided to take Justice Steven’s advice and find jurisdiction if either the Plurality’s or Justice Kennedy’s tests were met. The Third and Eighth Circuits have followed the First Circuit in this reasoning.
The Second, Fourth, Fifth, and Sixth Circuits have thus far avoided determining which approach to apply. These circuits have either accepted the parties’ stipulation that Justice Kennedy’s test applied or found that both tests have been met, thereby leaving resolution of a standard to a future case.
The Supreme Court has refused to grant certiorari in any of the cases attempting to resolve CWA jurisdiction. Where it has taken a case that raises the issue, it has carefully avoided the issue. Given the challenges associated both with the underlying scientific issues of determining hydrologic connectivity and parsing fractured opinions, the Supreme Court may be waiting for more percolation on the issue, in hopes of identifying a more manageable legal standard. In his Rapanos concurrence, Chief Justice Roberts also admonished the Corps for not promulgating a new rule clarifying their jurisdiction under the CWA in-light of the Court’s ruling in SWANCC. The Supreme Court may have hoped to have the agencies take up the issue and propose a rule before reconsidering the issues raised in Rapanos. As it stands, with the Trump administration’s delay of implementation of the Clean Water Rule pending a new rule being proposed, lower courts are left to grapple with the Rapanos decision.
VI. Moving Ahead
Perhaps the most interesting thing about the Rapanos opinion is not its lack of clarity, but that two justices saw fit to give lower courts advice on how to interpret it. While Chief Justice Roberts cited to Grutter and Marks, Justice Stevens advised courts to consider the votes of the dissenters. Unfortunately, neither directive has proved very helpful. As discussed above, applying Marks to Rapanos is problematic. Likewise, taking account of the dissenting justices, which effectively tries to predict the outcome of the case should the Court grant certiorari, raises concerns that judges are counting noses instead of applying the law. The confirmation of Justice Gorsuch to the bench and the rumors of Justice Kennedy’s retirement make clear that “counting noses” to find the “narrowest grounds” is not a reliable strategy. Should the current Court reconsider its holding in Rapanos, it is likely to split along similar lines, but if Justice Kennedy retires, the Court may take a new position either restraining, or broadening, federal jurisdiction.
Generally, the lower courts have determined that Justice Kennedy’s opinion constitutes the narrowest grounds, either because it would enjoy the support of a majority of justices (i.e. the fifth vote approach) or because it is the most deferential to the government’s authority. The Plurality opinion has never been considered the “narrowest” and has only been adopted as an alternative way to find jurisdiction. Notably, none of the courts have held that jurisdiction should be found when both the Plurality’s test and Justice Kennedy’s test are met. If Marks requires the position that the majority of the justices supporting the judgment of the Court must be found, then in the case of Rapanos this would require that both the Plurality’s and Justice Kennedy’s tests are met to find jurisdiction. In this way, the majority of those supporting the “narrowest” judgment would also support the corresponding outcome of the lower court on appeal.
Yet, lower courts have been reluctant to narrow the jurisdiction of the Corps under the CWA, largely because the language and congressional history of the Act support a broad reading to address the multitude of challenges to achieving clean water. This underlying purpose points to another approach for the lower courts to take, which several of them have, to interpret the Rapanos opinion in-light of the purpose of the CWA and grant deference to the Corps in their interpretation of both the act and the Rapanos opinion. Following SWANCC the outer bounds of the Corps’ jurisdiction are clearer. And, granting deference up to this outer bound where the Corps have otherwise met the less restrictive Rapanos opinion (either the Plurality’s or Justice Kennedy’s as the case may be) might hold truer to the intent of Congress in passing the CWA.
Unfortunately, until the agencies further clarify the definition of “waters of the United States,” or the Court deems it appropriate to clarify its opinions in both Marks and Rapanos, the lower courts will be left with little guidance. Perhaps Chief Justice Roberts was correct to cite Grutter for the proposition that Marks is unworkable in situations like Rapanos and the lower courts should look beyond Rapanos to determine jurisdiction under the CWA.
 See 83 Fed. Reg. 5200 (Feb. 6, 2018); Amena H. Saiyid, Pruitt Signs off on Blocking Clean Water Regulation, Water L. & Pol’y Monitor (BNA), Feb. 1, 2018.
 33 U.S.C. § 1251 et seq.
 547 U.S. 715 (2006).
 See e.g., Berkolow, Much Ado About Pluralities: Pride and Precedent Amidst the Cacophony of Concurrences, and Re-Percolation After Rapanos, 15 Va. J. Soc. Pol'y & L. 299, 319 (2008) (discussing the use of Marks in Rapanos analysis).
 United States v. Chevron Pipe Line Co., 437 F. Supp. 2d 605, 613 (N.D. Tex. 2006) (holding that under Fifth Circuit precedent dry stream beds were not “navigable waters” under the meaning of the CWA, the court did not consider Marks).
 United States v. Robison, 521 F. Supp. 2d 1247, 1248 (N.D. Ala. 2007) (“Remarkably, … the Eleventh Circuit held that a test which serves to broaden federal jurisdiction (‘i.e., less restrictive of CWA jurisdiction’) is the ‘less far reaching’ and ‘narrowest’ of two purported tests.”).
 United States v. Cundiff, 555 F.3d 200, 208 (6th Cir. 2009).
 Marks v. United States, 430 U.S. 188, 193 (1977) (“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.’” (citing Gregg v. Georgia, 428 U.S. 153, 169 n.15, (1976) (opinion of Stewart, Powell, and Stevens, JJ.)).
 33 U.S.C. § 1251.
 Id. at § 1311(a) (the term “pollutant” is defined in the Act, point source dischargers (commonly thought of as industrial sources) are able to apply for a pollution control permit from the EPA).
 Id. at § 1344 (“dredged or fill material” is not defined in the Act but is typically thought of to include fill dirt from uplands or dredged material removed to keep waterways open to ships, the Corps has authority to issue permits for deposition of dredged or fill material to “navigable waters”).
 The Daniel Ball, 77 U.S. 557 (1870) (defining “navigable waters” as navigable-in-fact “when they are used, or are susceptible of being used, in their ordinary condition, as highways for commerce, over which trade and travel are or may be conducted in the customary modes of trade and travel on water”).
 33 U.S.C. § 1362(7) (the CWA charges the EPA and Corps with further defining “waters of the United States”).
 United States v. Riverside Bayview Homes, 474 U.S. 121 (1985).
 Id. at 133 (wetlands were defined as “those areas that are inundated or saturated by surface or ground water at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions”).
 531 U.S. 159 (2001).
 Id. at 163.
 Id. at 171. The Court also discussed concerns that the Migratory Bird Rule may be beyond Congress’ authority to regulate under the Commerce Clause, and that the rule would be a “significant impingement of the States’ traditional . . . power over land and water use.” Id. at 174.
 See, e.g., United States v. Hubenka, 438 F.3d 1026, 1030–31 (10th Cir. 2006) (recognizing that Congress intended to define waters covered by the act broadly).
 Rapanos, 547 U.S. at 716. The Rapanos decision came from two consolidated cases. In the first, John Rapanos had filled wetlands without the appropriate permits. The wetlands on the Rapanos’ property connected remotely through ditches or man-made drains to the Lake Huron and Tittabawassee River. Id. at 729. In the second, Carabell v. Army Corps of Eng’rs, 257 F.3d 704, the Carabell’s had sought, and were denied, a permit to fill wetlands on their property. The Corps denied the permit because of the damage caused to water quality, wildlife, and overall ecology of the area. The wetlands were separated by a dirt berm from a man-made ditch that connected to a creek and eventually entered Lake St. Clair. The district court found that the berm did not always block overflow from wetlands from entering the ditch and rejected the Carabell’s challenge. Id. at 706.
 Rapanos, 547 U.S. at 739 (citing Webster’s Second for the internally quoted phrases).
 Id. at 732, n.5 (The Plurality went on to state that: “Common sense and common usage distinguish between a wash and seasonal river.”).
 See Jeffrey G. Miller, Plain Meaning, Precedent, and Metaphysics: Interpreting the “Navigable Waters” Element of the Clean Water Act Offense, 45 Envtl. L. Rep. News & Analysis 10548, 10569 (2015) (analyzing lower courts’ application of the Plurality’s test). Miller also provides a more in-depth critique of the Plurality’s approach.
 Rapanos, 547 U.S. at 742 (emphasis added).
 Id. (discussing the Riverview and SWANCC opinions to distinguish past precedent).
 See id. at 733–35. The Plurality also felt it important that Congress had recognized the rights of the States in the CWA and felt that the Corps’ interpretation would severely restrict state autonomy.
 Id. at 759 (Kennedy, J., concurring). Justice Kennedy’s opinion focused almost solely on wetlands and did not address tributaries, except to take issue with the Plurality’s requirement that they be “relatively permanent.” Id. at 769.
 Id. at 779. Justice Kennedy believed that by requiring a significant nexus to a traditionally navigable water he was giving some meaning to Congress’ use of the term “navigable”.
 Id. at 780.
 Id. at 782.
 Id. at 788 (citing Chevron v. NRDC, 467 U.S. 837 (1984)) (when statutory language is ambiguous the court will grant deference to the agency’s interpretation).
 Id. at 810.
 Id. Justice Stevens included a footnote, perhaps to provide some guidance in-light of Chief Justice Robert’s reference to Marks. “I assume that Justice Kennedy's approach will be controlling in most cases because it treats more of the Nation’s waters as within the Corps’ jurisdiction, but in the unlikely event that the plurality's test is met but Justice Kennedy’s is not, courts should also uphold the Corps’ jurisdiction. In sum, in these and future cases the United States may elect to prove jurisdiction under either test.” Id. at 810, n.14.
 See id. at 810.
 Id. at 758.
 Id. (citing Grutter v. Bollinger, 539 U.S. 306, 325 (2003) (discussing Marks v. United States, 430 U.S. 188 (1977)).
 See Berkolow, supra note 4, at 319.
 Grutter v. Bollinger, 539 U.S. 306, 325 (2003) (citing Nichols v. United States, 511 U.S. 738, 745–746, (1994)).
 Marks, 430 U.S. at 193–94.
 Id. at 194 (citing A Book Named “John Cleland's Memoirs of a Woman of Pleasure” v. Attorney Gen. of Com. of Mass., 383 U.S. 413, 419 (1966)). In Memoirs the plurality opinion had struck down the conviction but also left plenty of room for finding materials obscene. Marks, 430 U.S. at 194. See also Berkolow, supra note 4, at 322–26 (discussing the Marks opinion’s analysis of Memoirs).
 Gregg v. Georgia, 428 U.S. 153, 168–69 (1976) (citing Furman v. Georgia, 408 U.S. 238 (1972)).
 Id. at 169 n.15 (“Since five Justices wrote separately in support of the judgments in Furman, the holding of the Court may be viewed as that position taken by those Members who concurred in the judgments on the narrowest grounds Mr. Justice Stewart and Mr. Justice White.”).
 Id. at 189 (citing Furman v. Georgia, 408 U.S. 238, 308 (1972) (Stewart, J., concurring)).
 See id.; Marks, 430 U.S. at 194 (“Memoirs therefore was the law.”).
 Marks, 430 U.S. at 194.
 See Ryan C. Williams, Questioning Marks: Plurality Decisions and Precedential Constraint, 69 Stan. L. Rev. 795, 808 (2017).
 Id. at 811.
 Lisk v. Lumber One Wood Preserving, LLC, 792 F.3d 1331, 1337 (11th Cir. 2015) (discussing the challenges of applying Marks).
 Marks, 430 U.S. at 194 (the concurrences would have either found that the first amendment served as an absolute bar to obscenity regulation, or that only “hardcore pornography” would be considered obscene).
 United States v. Duvall, 740 F.3d 604, 610 (D.C. Cir. 2013) (Kavanaugh, J., concurring in the denial of rehearing en banc).
 Williams, supra note 48, at 808 (citing United States v. Robison, 521 F.3d 1319, 1323 (11th Cir. 2008) (Wilson, J., dissenting from the denial of rehearing en banc)).
 See Gregg, 428 U.S. at 188 n.36.
 Williams, supra note 48, at 814.
 Marks, 430 U.S. at 194. See also id.
 See Williams, supra note 48, at 815.
 Rapanos, 547 U.S. at 810.
 United States v. Robison, 505 F.3d 1208, 1221 (11th Cir. 2007).
 Id. (describing the “least far-reaching” as being the least restrictive of CWA jurisdiction).
 Williams, supra note 48, at 817. See also Duvall, 740 F.3d at 613 (D.C. Cir. 2013) (discussing how to arrive at a result consistent with precedent when there is no “common rationale” between the fractured opinions).
 See United States v. Robertson, 496 F.3d 993, 1289 (9th Cir. 2017).
 Rapanos, 547 U.S. at 758 (Roberts, C. J., concurring).
 See generally Kristen Clark, Navigating Through the Confusion Left in the Wake of Rapanos: Why a Rule Clarifying and Broadening Jurisdiction Under the Clean Water Act is Necessary, 39 Wm. & Mary Envtl. L. & Pol'y Rev. 295, 306–08 (2014).
 464 F.3d 723 (2006).
 Id. at 724–25.
 Id. at 725.
 Id. The Gerke court did not foreclose application of the Plurality’s test in future cases where jurisdiction would be met under that test, it only held that Justice Kennedy’s test governed the current litigation. Id.
 N. Cal. River Watch, 496 F.3d 993, 999–1000 (9th Cir. 2007) (stating that Justice Kennedy’s concurrence provided “the controlling rule of law for our case” and that it is “the narrowest ground to which a majority of the Justices would assent if forced to choose in almost all cases”); United States v. Robison, 505 F.3d 1208, 1219–21 (11th Cir. 2007) (recognizing that Marks does not easily apply to Rapanos, but stating that the court “simply cannot avoid the command of Marks,” that Marks does not allow lower courts to consider the opinion of the dissent, and determining that the “narrowest” opinion would be least-restrictive of CWA jurisdiction); see also United States v. Robertson, 875 F.3d 1281, 1292 (9th Cir. 2017).
 Berkolow, supra note 4, at 336.
 Robison, 505 F.3d at 1219.
 467 F.3d 56 (1st Cir. 2006).
 Id. at 64–66 (noting that the Seventh Circuit assumed that the narrowest grounds would be the opinion which granted the most deference to the government, but questioning how that logic would be applied when the government wasn’t a party to the litigation, and discussing the constitutional implications of granting deference to the government when the government’s interpretation may extend beyond Congress’ commerce clause authority).
 United States v. Donovan, 661 F.3d 174, 183 (3rd Cir. 2011); United States v. Bailey, 571 F.3d 791, 799 (8th Cir. 2009).
 See Cordiano v. Metacon Gun Club, 575 F.3d 199 (2d Cir. 2009); United States v. Cundiff, 555 F.3d 200, 208–12 (6th Cir. 2009) (the court engaged in an extensive analysis of Marks vis-à-vis Rapanos and highlighted many of the problems associated with attempting to apply Marks to Rapanos but decided that both tests were met so it didn’t need to pick one); United States v. Lucas, 516 F.3d 316 (5th Cir. 2008). The Fourth Circuit considered whether wetlands were jurisdictional in Precon Development Corp. v. Army Corps Eng’rs, 633 F.3d 278 (4th Cir. 2011), the court accepted the parties’ stipulation that Justice Kennedy’s test controlled and noted that application of the Plurality’s test would be “questionable” under the facts of the case. Id. at 288, n.9.
 United States v. Donovan, 661 F.3d 174 (3d Cir. 2011), cert. denied, 2012 WL 1190315 (U.S. 2012); United States v. Cundiff, 555 F.3d 200 (6th Cir. 2009), cert. denied, 130 S. Ct. 74 (2009); Northern California River Watch v. City of Healdsburg, 496 F.3d 993, 64 (9th Cir. 2007), cert. denied, 128 S. Ct. 1225 (2008).
 See U.S. Army Corps of Engineers v. Hawkes Co., 136 S. Ct. 1807 (2016) (ruling that a jurisdictional determination is final agency action).
 See Berkolow, supra note 4, at 344 (discussing the Supreme Court allowing challenging legal issues to “re-percolate” in the lower courts after handing down a less than clear standard).
 Rapanos, 547 U.S. at 757 (Roberts, C.J., concurring).
 See Saiyid, supra note 1.
See generally Miller, supra note 24, at 10551 (discussing congressional history of the CWA).