The Clean Water Act (CWA) governs the discharge of pollutants into waters of the United States. Supreme Court rulings and agency rulemakings that define the reach of this act have considerable consequences for protection of US waters and wetlands. Defining “waters of the United States” has been attempted by the Obama administration, the Trump administration, and now the Biden administration is again working to define what waters are protected under the CWA. However, the Supreme Court’s decision to hear Sackett v. EPAthis fall will potentially shape EPA’s rulemaking, implementation, and breadth of its authority under the CWA.
Waters of the United States
Which waterbodies are considered waters of the United States (WOTUS) determines what receives CWA protection. EPA administers much of the CWA, including under section 402 and 303. The Army Corps of Engineers (“Corps”) issues Section 404 Permits for discharge of dredge and fill material into navigable water. (The CWA defines “navigable waters” as “the waters of the United States, including the territorial seas.”) These permits can be critical in protecting wetlands, but which wetlands are protected depends on the definition of WOTUS.
During the past three presidential administrations, EPA and the Corps have issued multiple rules defining WOTUS. The Obama Administration published the Clean Water Rule in June 2015. The Clean Water Rule referenced Justice Kennedy’s concurring opinion in Rapanos v. EPA, which I discuss below. This rule defined WOTUS to include eight categories of jurisdictional waters. Soon after EPA finalized the Clean Water Rule, it was challenged in multiple lawsuits.
Under the Trump administration, EPA and the Corps repealed the Clean Water Rule. EPA and the Corps then issued the Navigable Waters Protection Rule (NWPR) in 2020. Under this rule, four categories of waters were considered to be within the jurisdiction of the CWA. One of these categories was for “perennial and intermittent tributaries that contribute surface water flow” to navigable waters, which aligned more closely to Justice Scalia’s plurality opinion in Rapanos.
Again, several challenges were filed, and on August 30, 2021, the U.S. District Court for the District of Arizona vacated the rule. In response, the Biden administration’s EPA and Corps began interpreting WOTUS “consistent with the pre-2015 regulatory regime.” However, EPA recognized the 14 additional pending cases challenging either, or all of the prior rules, (the 2015 rule, the rule repealing the 2015 rule, and the NWPR) and took the regulatory step in a December 2021 proposal to update the regulations to reflect the pre-2015 definition of WOTUS. EPA has also initiated a process to hear from stakeholders to support a second rulemaking step, which would refine the definition of WOTUS.
Supreme Court Addressing WOTUS
The Supreme Court has addressed the definition of WOTUS multiple times. In United States v. Riverside Bayview Homes Inc., the Supreme Court found that the Corps’ interpretation of the Clean Water Act, which included wetlands in navigable waters and thus WOTUS, was reasonable. The Court confirmed that “navigable water” applied to wetlands that were adjacent to navigable waters.
In a subsequent case, the Court addressed the definition of WOTUS in Solid Waste Agency of Northern Cook County v. U.S. Army Corps of Engineers (“SWANCC”). Unlike the wetlands at issue in Riverside Bayview, the wetlands in SWANCC were not adjacent to navigable waters. In this case, the waters at issue were isolated ponds that served as habitat for migratory birds. The Court found that these isolated waters were not navigable waters. The Court distinguished this case from earlier precedent on the basis that unlike the wetlands adjacent to navigable waters at issue in Riverside Bayview, there was no significant nexus between the wetlands and the navigable waters. The Court concluded while the term ‘navigable’ may have a limited effect, granting isolated ponds status as navigable waters should not cause the term ‘navigable’ to be devoid of significance.
Significant nexus was a key focus in the next Supreme Court WOTUS case – Rapanos v. United States. However, there was no majority opinion in Rapanos. Instead, Justice Scalia wrote a plurality opinion, and Justice Kennedy wrote a concurring opinion. Thus, the Court was split 4-1-4 with Chief Justice Roberts and Justices Thomas and Alito joining Justice Scalia’s opinion, Justice Kennedy writing the concurrence, and Justice Stevens authoring the dissent which Justices Souter, Ginsburg, and Breyer joined. Although they reached the same conclusion, the differences between Justice Scalia’s and Justice Kennedy’s reasoning have caused confusion in the lower courts and for each of the rulemakings.
In his opinion, Justice Scalia engaged in a textualist analysis of the CWA looking to the dictionary definition of waters. Scalia’s opinion concludes that navigable waters, and thus WOTUS, cannot refer to channels that carry intermittent water, like ditches, because other sections of the CWA define such conduits as point sources. Thus, under the plurality opinion, point sources and navigable waters are separate, distinct categories. To determine what waters are navigable and thus subject to the CWA, Justice Scalia explained a two-step test: “first, that the adjacent channel contains a ‘wate[r] of the United States,’ (i.e., a relatively permanent body of water connected to traditional interstate navigable waters); and second, that the wetland has a continuous surface connection with that water, making it difficult to determine where the ‘water’ ends and the ‘wetland’ begins.”
Justice Scalia also explained that including intermittent flows would impinge on powers that traditionally belong to the states and that “[w]e ordinarily expect a ‘clear and manifest’ statement from Congress to authorize an unprecedented intrusion into traditional state authority”. The Trump administration’s Navigable Waters Protection Rule relied on the plurality’s reasoning.
In contrast, Justice Kennedy’s concurrence established that there needs to be “a significant nexus between the wetlands in question and navigable waters in the traditional sense” and that nexus needs to be assessed with regard to CWA’s purpose and goals. The concurrence also addressed constitutional concerns and explained that the legitimacy of such concerns “in some circumstances does not require the adoption of an interpretation that departs in all cases from the Act’s text and structure.” As I note above, the Obama administration’s Clean Water Rule adopted much of Justice Kennedy’s opinion.
The plurality opinion has created confusion over what waters fall under the CWA since different circuit courts have interpreted Rapanos in different ways. For example, the Seventh, Ninth, and Eleventh Circuits follow the test put forward in Justice Kennedy’s concurrence. However, the First, Third, and Eighth Circuits have found that a body of water can be considered navigable water if it meets either of Justice Scalia’s or Kennedy’s tests.
Sackett v. EPA
The Supreme Court recently agreed to hear Sackett v. EPA, which is not the first time for this case to be before the Court. In 2004, Michael and Chantell Sackett bought a residential lot near Priest Lake, Idaho. EPA notified the Sacketts that they could not place fill on their lot because wetlands on the property fell under the CWA. The Sacketts sued EPA arguing that the CWA did not apply to their property, but the case was dismissed for a lack of subject-matter jurisdiction. The Sacketts appealed the case to the Ninth Circuit then the Supreme Court. In this first case before the Supreme Court, (“Sackett I”), the Court held that the Sacketts could bring a civil action under the Administrative Procedures Act (APA) as EPA’s action constituted a final agency action for which there is no other adequate remedy in court outside the APA. Thus, the Court remanded the case to the lower courts allowing it to proceed on the merits.
On remand, the lower court upheld EPA’s determination that the wetlands on the Sackett’s property are WOTUS based on several factors including, for example that the wetlands were adjacent to a navigable body of water and connected by a “shallow subsurface” flow to the adjacent lake. Applying the Justice Kennedy test under Rapanos, the court of appeals affirmed the lower court’s decision.
For the case currently before the Court (“Sackett II”), the question the Supreme Court will examine is “whether the Ninth Circuit set forth the proper test for determining whether wetlands are ‘waters of the United States’ under the Clean Water Act, 33 U.S.C. §1362(7).” This question sets the Court to potentially clarify what test (Justice Scalia’s or Justice Kennedy’s) should govern the definition of WOTUS. The petitioners are arguing that Justice Kennedy’s significant nexus test should be abandoned. They urge the Court to apply a two-step test similar to the plurality in Rapanos but which would place further emphasis on potential Constitutional questions by specifically looking for if the water is under Congress’s commerce clause authority
In its brief, the Biden administration argues that the application of a “restrictive version of the ‘continuous surface connection’ test articulated by the plurality…has no grounding in the CWA’s text, structure, or history.” It also notes that it would “seriously compromise the Act’s comprehensive scheme by denying protection to many adjacent wetlands—and thus the covered waters with which those wetlands are inextricably linked.” The administration points out that the petitioner’s approach would lead to arbitrary outcomes where a small surface connection would result in a CWA determination but a “pervasive hydrological connection between a waterway and an adjacent wetland” would not, and the Act’s coverage could “come and go as floods or storms created or breached natural barriers like berms and dunes.”
As the Court will hear oral arguments in October, a decision is likely in 2023. Thus, the timing of a decision and EPA’s expected rulemaking will be critical to watch.
Agency Rulemakings Going Forward
Hydrologic connectivity is complex, and EPA and the Corps are responsible to draw the lines of jurisdiction under the CWA based on the legal precedents and the hydrology of the site. As the agencies work to propose and finalize their rulemakings, federal agencies, landowners, companies, and other regulated entities need to understand what rules apply where. However, as EPA has noted leading into and during the listening sessions it has held in advance of its rulemaking, hydrologic conditions differ throughout the country. A key challenge in defining WOTUS is to draw jurisdiction lines that are applicable and appropriate to all parts of the country.
It is unclear whether agencies will finalize a new rule prior to a decision by the Court, but the breadth of the decision on the agencies authority to define WOTUS will impact the jurisdictional reach of the CWA on the country’s waters and wetlands.
 33 U.S.C. §§ 1251–1387.
 Sackett v. Env’t Protection Agency, 8 F.4th 1075 (9th Cir. 2021), cert. granted Jan. 24, 2022.
 Section 402 establishes the national pollution discharge elimination system which is a national permit program administered by EPA, states, or Indian tribes. Section 303 has two major parts. The first is for states and tribes to adopt water quality criteria, subject to EPA approval. The second part is for states and tribes to identify any waters that may not meet the quality criteria and create total maximum daily loads of pollutants for those waters. See, e.g., Percival et al., Environmental Regulation: Law, Science, and Policy 587 (9th ed. 2021).
 33 U.S.C. §1362(7).
 80 Fed. Reg. 37054 (Jun. 29, 2015).
 Id. at 37056.
 Id. at 37057.
 84 Fed. Reg. 56626 (Oct. 22, 2019).
 85 Fed. Reg. 22250 (Apr. 21, 2020).
 Id. at 22251.
 Pasqua Yaqui Tribe v. US EPA, No. CV-20-00266, 2021 WL 3855977 (D. Ariz. Aug. 30, 2021).
 86 Fed. Reg. 69372, 69272 (Dec. 7, 2021).
 474 U.S. 121 (1985)
 Id. at 133.
 In Nat. Res. Def. Couns. v. Callaway, the court rejects a narrower reading of the Clean Water Act that limited the statute to traditionally navigable waters. 392 F. Supp. 685, 686 (D.D.C. 1975).
 531 U.S. 159 (2001).
 Id. at 171–72.
 Id. at167.
 Id. at 172.
 547 U.S. 715 (2006).
 In a plurality opinion, at least five justices agree on the result, but no legal reasoning is shared by enough justices to establish a majority.
 Id. at 732.
 Id. at 736.
 Id. at 742.
 Id. at 738.
 Id. at 779.
 Id. at 783.
 Orchard Hill Bldg. Co. v. United States Army Corps of Eng’rs, 893 F.3d 1017, 1021 (7th Cir. 2018) (“Rapanos did not produce a majority opinion, and without one to definitively answer the question, we have held that Justice Anthony Kennedy’s concurrence controls.” citing United States. v. Gerke Excavating, Inc. 723, 724–725 (7th Cir. 2006).
 N. Cal. River Watch v. City of Healdsburg, 496 F.3d 993, 999–1000 (9th Cir. 2007) (“Justice Kennedy’s concurrence provides the controlling rule of law for our case.”).
 United States v. Robison, 505 F.3d 1208, 1221 (11th Cir. 2007) (we join the Seventh and Ninth Circuits’ conclusion that Justice Kennedy’s ‘significant nexus’ test provides the governing rule of Rapanos”).
 United States v. Johnson, 467 F.3d 56, 60 (1st Cir. 2006) (“We conclude that the United States may assert jurisdiction over the target sites if it meets either Justice Kennedy’s legal standard or that of the plurality.”).
 United States v. Donovan, 661 F.3d 174, 184 (3rd Cir. 2011) (“we find that Rapanos establishes two governing standards”).
 United States v Bailey, 571 F.3d 791, 799 (8th Cir. 2009) (“we join the First Circuit in holding that the Corps has jurisdiction over wetlands that satisfy either the plurality or Justice Kennedy’s test”).
 Sackett v. Env’t Protection Agency, 8 F.4th 1075 (9th Cir. 2021), cert. granted Jan. 24, 2022.
 Id. at 1708.
 Sackett v. Envt’l Protection Agency, No. 08-CV-185-N-EJL, 2008 WL 3286801 (D. Idaho Aug. 7, 2008).
 Sackett v. Envt’l Protection Agency, 622 F.3d 1139 (9th Cir. 2010).
 Sackett v. Envt’l Protection Agency, 566 U.S. 120 (2012).
 Id. at 127.
 Id. at 131.
 March 2019: Sackett v. Envt’l Protection Agency, No. 2:08-cv-00185-EJL, 2019 WL 13026870 (D. Idaho Mar. 31, 2019).
 Sackett v. Envt’l Protection Agency, 8 F.4th 1075, 1091 (9th Cir. 2021).
 21-454 Sackett v. Envt’l Protection Agency.
 Brief for Petitioner, Sackett v. Envt’l Protection Agency, (No. 21-454).
 Brief for the Respondents at 17, Sackett v. Envt’l Protection Agency, (No. 21-454).
 Id. at 18.