Last week the Supreme Court of the United States issued its decision in Sackett v. EPA, clarifying what wetlands are subject to federal jurisdiction and regulation under the Clean Water Act (CWA). The Sackett case was brought by property owners after the Environmental Protection Agency (EPA) prevented them from backfilling their residential lot to build a home. The EPA’s position was that the Sacketts’ lot contained wetlands that qualified as jurisdictional “waters of the United States” (WOTUS) because the wetlands were near a ditch that fed into a creek which in turn fed into a nearby lake. The district court agreed with the EPA, entering summary judgment against the Sacketts. The United States Court of Appeals for the Ninth Circuit affirmed.

In Sackett, the Supreme Court reversed the lower court and ruled for the Sacketts, concluding that wetlands on their property were not subject to regulation under the CWA. The Court clarified that wetlands are covered waters only when they share a “continuous surface connection” to bodies of water that are covered in their own right, significantly narrowing the federal government’s jurisdiction over wetlands under the CWA.

Defining “Waters of the United States”

Congress provides for the regulation of wetlands under the CWA, which is jointly enforced by the EPA and the Army Corps of Engineers (Corps). The CWA prohibits “the discharge of any pollutant” into “navigable waters.” 33 U.S.C. §§ 1311(a), 1362(12)(A). The CWA first defined “navigable waters” as “the waters of the United States, including the territorial seas,” 33 U.S.C. § 1362(7). Congress later amended the CWA, clarifying that it extends to wetlands “adjacent” to traditional waters of the United States. 33 U.S.C. § 1344(g)(1). Eventually the EPA and Corps issued regulations defining WOTUS similarly, claiming jurisdiction over wetlands “adjacent” to other covered waters. See 45 Fed. Reg. 33424 (1980); 47 Fed. Reg. 31810–31811 (1982). Federal courts and agencies have struggled to limit the breadthof these definitions ever since.

The Supreme Court tried to clarify which wetlands were covered by the CWA in Rapanos v. United States, 547 U.S. 715 (2006). That decision offered two tests for CWA jurisdiction, though neither was backed by a majority of the Court. A plurality of the Court held that the CWA regulates “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.”  Rapanos, 547 U.S. at 742. Alternatively, Justice Kennedy’s concurrence opined that the CWA regulates wetlands with a “significant nexus” to covered waters, meaning wetlands that, whether or not they share a surface connection, “significantly affect the chemical, physical, and biological integrity” of covered waters. Id. at 759, 779–780.

Rather than clarify, Rapanos created further confusion. First, there was confusion over how to interpret and apply the Rapanos decision, since neither the “continuous surface connection” test nor the “significant nexus” test enjoyed majority support. Second, the Rapanos decision prompted a series of conflicting federal rulemakings that attempted to adopt a specific regulatory definition of “Waters of the United States” that would delineate jurisdictional wetlands.

Under the Obama Administration, the EPA and the Corps adopted a version of the significant nexus test, giving federal agencies case-by-case discretion to determine whether a wetland had the required “significant nexus” with another jurisdictional water. 80 Fed. Reg. 37105, 37116. That rule was repealed and replaced by the Trump Administration, which narrowed federal jurisdiction to only wetlands that are adjacent to jurisdictional waters, though “adjacent” still included certain wetlands that were physically separated from covered waters. 85 Fed. Reg. 22338, 22340. Then the Biden Administration promulgated yet another rule, which would have again expanded federal jurisdiction over wetlands, reaching wetlands with a “significant” hydrological or ecological “nexus” to those protected waters. 88 Fed. Reg. 3143–3144.

The Sackett Decision

The Court in Sackett has provided some clarity by limiting the scope of federal jurisdiction over wetlands. Unlike Rapanos, the Sackett decision has issued a majority opinion that sets clear limits on what wetlands are subject to federal regulation under the CWA.

First, Sackett has eliminated the old “significant nexus” test applied by many courts after Rapanos and at various times used by the EPA and the Corps. The decision explains that because “the CWA never mentions the ‘significant nexus’ test . . . the EPA has no statutory basis to impose it.”  Sackett v. Env’t Prot. Agency, No. 21-454, 2023 WL 3632751, at *15 (U.S. May 25, 2023).

Second, Sackett affirmatively adopts the “continuous surface connection” jurisdictional test.  The majority explains that “the CWA’s use of ‘waters’ encompasses ‘only those relatively permanent, standing or continuously flowing bodies of water ‘forming geographic[al] features’ that are described in ordinary parlance as ‘streams, oceans, rivers, and lakes.’” Id. at *10. And it concludes that “the CWA extends to only those ‘wetlands with a continuous surface connection to bodies that are ‘waters of the United States’ in their own right” such that they are “‘indistinguishable’ from those waters.” Id. at *17.

Here the Court has effectively redefined what it means to be an adjacent wetland. Where “adjacent” once swept in wetlands that, though not directly connected with covered waters, were indirectly connected and in close proximity to those waters, Sackett says that sweeps too broadly. The Court in Sackett concludes that “[w]etlands that are separate from traditional navigable waters cannot be considered part of those waters, even if they are located nearby.” Id. at *13. After Sackett, the use of the phrase “adjacent wetlands” in the CWA and its implementing regulations should be limited to include only wetlands that are “adjoining” or “directly connected” to traditional waters of the United States via a continuous surface connection.

Finally, Sackett notes that although wetlands must share a continuous surface connection with covered water to be covered themselves, artificial barriers constructed for the purpose of breaking such a surface connection will not remove wetlands from federal jurisdiction. Responding to concerns that the “continuous surface connection” test will leave too many wetlands unregulated, the majority explains that though existing barriers between wetlands and covered water can remove that wetland from federal jurisdiction, property owners “cannot carve out wetlands from federal jurisdiction by illegally constructing a barrier on wetlands otherwise covered by the CWA.” Id. at *14, n.16.

Sackett’s Regulatory Impact

The Sackett ruling likely means that the Biden administration’s recently promulgated WOTUS rule, which relies in part on the old “significant nexus” test, is unlikely to survive the numerous legal attacks lodged against it, since it now exceeds the maximum reach of the federal government’s CWA jurisdiction (and the rule’s application had already been blocked by federal courts in several states). Further attempts to reimpose a definition resembling the “significant nexus” test will likely be blocked by federal courts, unless Congress provides additional authority to EPA and the Corps.

Questions remain even after Sackett. For example, how “continuous” must a “continuous surface connection” be to create jurisdiction over a wetland? What about surface connections that exist for most of the year, but occasionally dry up in the summer? What about wetlands that are separated from covered water by an obvious barrier—but one that is frequently inundated? Though it remains to be seen how EPA and the Corps will interpret “continuous surface connection,” they may interpret the phrase in ways that confer the broadest jurisdiction possible, either in new proposed rules or in agency guidance. However, it will take some time for the agencies to respond to Sackett. And attempts by agencies to creatively read “continuous surface water connection” in ways that expand jurisdiction—like what occurred after Rapanos–will be scrutinized by federal courts.

Note, however, that while Sackett considerably narrows federal jurisdiction over wetlands, it does nothing to limit state and local authority over wetlands. The Sackett majority explains that even though some regulated wetlands are now beyond the reach of the CWA, that does not mean they will go unregulated. That is because wetlands that fail the “continuous surface connection” test for federal CWA jurisdiction may still be regulated under state environmental laws. States may, if they choose, enact more stringent environmental regulations than what is allowed at the federal level under the CWA.