On Sept. 8, 2023, the U.S. Environmental Protection Agency (EPA) and U.S. Army Corps of Engineers (ACE) changed the regulatory definition of the term “waters of the United States” (WOTUS). This is the fifth time that this definition – which determines the scope of the Clean Water Act – has been amended within 8 years.

This latest amendment conforms the definition of WOTUS to the U.S. Supreme Court’s decision earlier this year in the case of Sackett v. EPA. In a unanimous 9-0 ruling, the Sackett decision limited the scope of the Clean Water Act by providing that a waterbody qualifies for WOTUS protections only if it

  • is navigable, or supports interstate commerce;
  • flows across or forms part of a state’s boundaries; or
  • maintains a continuous surface connection to navigable waters.

New language included as part of this redefinition — as well as language missing from the updated guidelines — promise to dramatically shift the regulatory landscape for such crucial waterbodies as wetlands and streams.

Streams and Wetlands Lose Clean Water Act Protections

This post-Sackett redefinition is a departure from criteria promulgated by EPA and ACE in January 2023, which upheld WOTUS status for wetlands and intermittent streams so long as they maintained a “significant nexus” to other waters receiving Clean Water Act protections. This had been the applicable standard in about 50% of U.S. states. In Sackett v. EPA, the Supreme Court rejected the “significant nexus” test outright.

The Sackett rule became effective on the day it was published. No public comments were sought or accepted on any draft of the rule.

Testifying before the U.S. Senate Committee on Environment and Public Works in October, Clemson University (South Carolina) Ecologist Mažeika Patricio Sulliván estimated that approximately 6.6 million ha (16.3 million ac) of wetlands — an area roughly the size of West Virginia — will lose federal protections as a result of the Sept. 8 redefinition. Additionally, Sulliván noted that non-permanent, ephemeral, and intermittent streams, which represent about 59% of all streams in the conterminous U.S., are also now unprotected under the Clean Water Act — amounting to at least 7.7 million km (4.8 million mi) of streams.

Unlike previous WOTUS definitions, the Sept. 8 rule also does not identify exclusions for artificial or nature-based stormwater and flood control features. This lapse means discharging pollutants into artificial or nature-based stormwater and flood control features may require a National Pollutant Discharge Elimination System (NPDES) permit under section 402 of the Act while dredging or filling previously-protected wetlands may no longer require a permit under section 404.

Wetlands Regulation Will Continue to Vary by State

More than 20 U.S. states rely on the federal definition of WOTUS to regulate activities within waters in their borders. Many of these states even prohibit state-level legislators from adopting laws or regulations that exceed federal law.

In May 2023, the U.S. Supreme Court unanimously ruled that wetlands and streams only qualify for federal protections under the Clean Water Act if they maintain a continuous surface connection to navigable or interstate waters. The ruling prompted the U.S. Environmental Protection Agency to redefine “Waters of the United States” in September. Image courtesy of Mark Thomas/Pixabay

In these states, regulation of activities affecting streams and wetlands has shrunk alongside the scope of federal law. Especially in arid and mountainous areas, stormwater managers may need to reconsider whether existing discharge and dredge-and-fill permits are valid or need to be renewed if the system discharges to or affects a streambed with ephemeral or intermittent flows.

The remaining states have laws that protect waters more expansively than federal law. In these states, stormwater managers will likely need to shift their focus from the permitting and enforcement standards of federal law and onto the standards articulated in state laws.

For example, a biology or hydrology study that evaluated the presence of wetlands within a project area using a “significant nexus” test would no longer be consistent with federal law and may need to be updated to consider the standards articulated under state law. A project affecting a wetland that does not have a continuous surface connection to a traditional navigable water, for example, would probably not require a federal Section 404 dredge-and-fill permit for construction and maintenance, or a Section 402 discharge permit for operation. That same project, however, may require state permits for dredging, filling, and discharging activities.

Significant Uncertainty Remains

In absence of further guidance from courts or federal agencies, the Sackett decision leaves additional areas of uncertainty for stormwater and flood control programs.

Temporary interruptions. The court in Sackett recognized that temporary interruptions in a surface connection or flow due to drought or low tides, for example, will not remove federal protections from a jurisdictional wetland, stream, lake, or other water body. The court and federal agencies, however, did not define what constitutes a “temporary” interruption to a “relatively permanent” waterbody.

Artificial barriers. The court noted that legally constructed artificial barriers between a water of the United States and a wetland ordinarily remove federal protections from the wetland. If the permit for the artificial barrier is revoked, would federal jurisdiction then extend to the wetland?

Estimates from the water sector hold that this recent redefinition will exclude approximately 16.3 million acres of wetlands and roughly 4.8 million miles of streams from federal protections. Image courtesy of fahad sahir/Pixabay

Artificial connections. The Sept. 8 redefinition excludes from federal jurisdiction ditches, including roadside ditches, that do not carry a relatively permanent flow of water. This exception, however, may not extend to ditches constructed in and draining dry land that may carry a relatively permanent flow of groundwater or other relatively permanent sources of water flows.

Similarly, under the new guidelines, wetlands may be jurisdictional if they are connected to protected waters by features such as an artificial ditch or pipe if that feature provides a continuous surface connection.

In light of these uncertainties, it may be possible for artificial wetlands and other green infrastructure to become subject to federal jurisdiction if they have a continuous surface connection with an existing, protected WOTUS.

Indirect discharges. Inthe Supreme Court’s 2020 case, County of Maui v. Hawaii Wildlife Fund, the court determined that discharges to groundwater required an NPDES permit because the discharged pollutants were the “functional equivalent of a direct discharge” based on the time and distance traveled from the discharge point through the groundwater and to the Pacific Ocean. Under this reasoning, it is possible that a discharge to a non-jurisdictional stream or wetland may still require a federal NPDES permit if the discharge eventually reaches a jurisdictional water.

As a result, it is possible that soils and hydrogeology may still play a significant role in determining whether a stormwater or flood control project is subject to federal jurisdiction.

What’s Next

Over the next few months, stormwater and flood control agencies may see efforts to further define and clarify what water bodies qualify for WOTUS protections.

Litigation. The January 2023 WOTUS definition was subject to litigation and was stayed in 23 U.S. states. According to EPA, this litigation means that these states, as well as the District of Columbia and the U.S. territories, are following the Sept. 8 rule for determining when a water is regulated under the Clean Water Act. In the remaining 27 states, the agencies are interpreting WOTUS consistent with the pre-2015 rule and the Sackett decision until further notice.

In light of the lack of public comment on the Sept. 8 rule and the lack of guidance on the concepts of “relatively permanent” and “continuous,” it is possible the newest definition of WOTUS may also face legal challenges.

Legislation. In mid-October, legislators in the U.S. House of Representatives introduced the Clean Water Act of 2023, which proposes to amend the Clean Water Act to replace the terms “navigable waters” and “waters of the United States” with the term “protected water resources.” Protected water resources would then be broadly defined to include all the waters in the Sept. 8 rule, as well as all interstate and intrastate waters and their tributaries, wetlands, and impoundments. If this bill makes it through the legislative process, it would represent a significant expansion of the Clean Water Act over the Sept. 8 rule.

Local Regulation. In states that rely on federal law to protect streams and wetlands, it is possible that new state and local regulations may emerge to fill the regulatory gap left by Sackett. Stormwater managers may need to consider their role in adopting and complying with local regulations.

Top image courtesy of Alain Audet/Pixabay

Rebecca Andrews is a partner at the law firm of Best Best & Krieger, based in Houston and San Diego. Rebecca helps public agencies navigate environmental issues related to wastewater, stormwater, land use, and property development. Her practice focuses on Clean Water Act sections 402 and 404, the Safe Drinking Water Act, and state-level equivalents to these federal laws.