What is the jurisdictional reach of the Clean Water Act? The Act applies to “navigable waters”, which are defined as the “waters of the United States, including the territorial seas.” That’s all the CWA says about jurisdiction. Congress left it to the implementing agencies—EPA and the Corps of Engineers—and the courts to define the contours of CWA jurisdiction. In the 45 years following enactment, we are not much closer to clarity.

The 2019 proposed “waters of the U. S.” or WOTUS rule is the latest attempt and, like all its predecessors, it has generated a lot of controversy. Setting aside for the moment whether the rule is ultimately adopted and survives the inevitable court challenges, will it achieve the CWA’s object “to restore and maintain the chemical, physical, and biological integrity of the Nation's waters”? Unfortunately, the approach taken in the rule seeks an easy resolution to a complex problem as it avoids the interconnectedness of natural systems. That approach will be of limited use in meeting the CWA’s objective.

What it Means

The central strategy underlying the CWA is adoption by the states of water quality standards. The standards would be protected through grant funding of public treatment facilities on the one hand, and on the other, a regulatory program allowing for limited discharges of pollutants or filling of wetlands to ensure attainment of standards. Early cases looking at discharges or fills subject to the CWA stressed whether the receiving waters were “navigable in fact,” that is, capable of carrying interstate commerce. However, regulations adopted by the Corps of Engineers extended jurisdiction to tributaries and adjacent wetlands, as degradation of these results in degradation of the navigable waters. These regulations also included certain intermittent streams among WOTUS.

In its 2006 decision in Rapanos v. U. S., a majority of the Supreme Court found the regulations too broad, but did not quite agree as to why. Writing for the plurality, Justice Scalia criticized the Corps for regulatory overreach and argued for a common sense, dictionary understanding of WOTUS:

"In sum, on its only plausible interpretation, the phrase “the waters of the United States” 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.” See Webster’s Second 2882. The phrase does not include channels through which water flows intermittently or ephemerally, or channels that periodically provide drainage for rainfall.

In other words, if you can see it and your feet get wet when you stand on it, the CWA applies. Applying his usual strict constructionist approach, Justice Scalia found no statutory justification for a nuanced approach to jurisdiction. By Executive Order, President Trump directed EPA and the Corps to replace the Obama WOTUS rule with one based on Justice Scalia’s interpretation, and the proposed rules do just that.

Will this approach serve the stated objective of the CWA to protect our waters? Justice Kennedy, in his concurring opinion in Rapanos, thought not. He chastised both the plurality and the dissent for not applying the test established by the Court just five years earlier in Solid Waste Agency of Northern Cook Cty. v. Army Corps of Engineers. That case pegged jurisdiction to whether there is a “significant nexus” between the wetland in question and a navigable waterway. In SWANCC, the Court rejected Corps regulations that imposed jurisdiction over isolated wetlands because they served as habitat for migratory birds. That was not, per the Court, enough to show a significant nexus between those wetlands and a navigable waterway.

However, in Rapanos, Justice Kennedy argued that the Court must do the SWANCC analysis, with all its inherent complexity, before simply concluding there is no jurisdiction:

Taken together [prior Court opinions show that], the connection between a nonnavigable water or wetland and a navigable water may be so close, or potentially so close, that the Corps may deem the water or wetland a “navigable water” under the Act. In other instances, as exemplified by SWANCC, there may be little or no connection. Absent a significant nexus, jurisdiction under the Act is lacking.

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The required nexus must be assessed in terms of the statute’s goals and purposes. Congress enacted the law to “restore and maintain the chemical, physical, and biological integrity of the Nation’s waters,” 33 U. S. C. §1251(a), and it pursued that objective by restricting dumping and filling in “navigable waters,” §§1311(a), 1362(12). With respect to wetlands, the rationale for Clean Water Act regulation is, as the Corps has recognized, that wetlands can perform critical functions related to the integrity of other waters—functions such as pollutant trapping, flood control, and runoff storage. 33 CFR §320.4(b)(2). Accordingly, wetlands possess the requisite nexus, and thus come within the statutory phrase “navigable waters,” if the wetlands, either alone or in combination with similarly situated lands in the region, significantly affect the chemical, physical, and biological integrity of other covered waters more readily understood as “navigable.” When, in contrast, wetlands’ effects on water quality are speculative or insubstantial, they fall outside the zone fairly encompassed by the statutory term “navigable waters.”

The analysis called for by Justice Kennedy is complex and requires professional judgment. Granting agencies the discretion to exercise that judgment makes many uncomfortable, but such discretion is inherent in our current framework in which Congress provides vague direction that agencies must implement. There is much talk about the Supreme Court eviscerating Auer and Chevron deference to agency interpretations of their own rules or statute, but surely there must be some leeway for agencies that courts can find acceptable. If not, already ponderous and glacially slow regulatory processes will get only more so.

The Obama WOTUS rule took the Kennedy approach and then tried to put certain sideboards around it to determine CWA jurisdiction, which played to mixed reviews—a million comments and scores of legal challenges were filed. The Trump WOTUS rule swings the pendulum toward the simplistic Scalia approach, which will also draw broad opposition.

Getting clarity on the scope of CWA jurisdiction has proved elusive. However, in our zeal for clarity and preventing overly aggressive federal regulation, we must not lose sight of the clarion purpose Congress gave in enacting the CWA in the first place.