On Jan. 23, the U.S. Environmental Protection Agency (EPA) released revised rules defining what constitute waters of the United States under federal Clean Water Act (CWA) jurisdiction. The rule, entitled the Navigable Water Protection Rule, clarifies the definition of “waters of the United States.”¹ The final rule constitutes the second and final step of the administration’s plan to repeal and replace the controversial 2015 Clean Water Rule² that expanded the scope of waters regulated by the federal government compared to the 1986 rule.³

The revised rule, when it goes into effect, limits federal regulatory and enforcement jurisdiction under the CWA to:

• The territorial seas and traditional navigable waters
• Perennial and intermittent tributaries to those waters,
• Certain lakes, ponds, and impoundments, and
• Wetlands adjacent to jurisdictional waters.⁴

EPA Administrator Andrew Wheeler unveiled the revisions at a conference in Las Vegas in conjunction with the Jan. 23 announcement. In addition to describing what is regulated under the rulemaking, the final rule also clarifies what are not “waters of the United States.” The revised rule would remove jurisdiction over “ephemeral streams,” which are waters that only flow following large precipitation events. Ephemeral streams remain dry when not carrying the resulting stormwater to larger bodies of water. This regulation is expected to dramatically reduce federal CWA jurisdiction in arid states such as Arizona and Nevada. In addition, the finalized rule clarifies that the following waters are not regulated under the CWA as “waters of the United States”:

• groundwater, including groundwater drained through subsurface drainage systems;
• ephemeral features that flow only in direct response to precipitation, including ephemeral streams, swales, gullies, rills, and pools;
• diffuse stormwater runoff and directional sheet flow over upland;
• ditches that are not traditional navigable waters, tributaries, or that are not constructed in adjacent wetlands, subject to certain limitations;
• prior converted cropland;
• artificially irrigated areas that would revert to upland if artificial irrigation ceases;
• artificial lakes and ponds that are not jurisdictional impoundments and that are constructed or excavated in upland or non-jurisdictional waters;
• water-filled depressions constructed or excavated in upland or in non-jurisdictional waters incidental to mining or construction activity, and pits excavated in upland or in non-jurisdictional waters for the purpose of obtaining fill, sand, or gravel;
• stormwater control features constructed or excavated in upland or in non-jurisdictional waters to convey, treat, infiltrate, or store stormwater run-off;
• groundwater recharge, water reuse, and wastewater recycling structures constructed or excavated in upland or in non-jurisdictional waters; and
• waste treatment systems.⁵

The final rule follows a lengthy litigation and regulatory battle over how to define what waters are covered by the CWA. For many years a rule promulgated in 1986 was in place, but the Supreme Court placed the application of the 1986 rule in doubt by handing down a 4-1-4 ruling in Rapanos v. United States, 547 U.S. 715 (2006). The 2015 Clean Water Rule finalized by the Obama administration attempted to address the thorny legal issues, but ultimately with an expansive definition that faced significant opposition in courts. It is likely that this rule will also face legal challenges from numerous environmental groups. However, because of the changes to the makeup of the Supreme Court since the Rapanos decision, it is likely that the 2020 Navigable Water Protection Rule rule will ultimately survive legal challenges.

Additionally, should the November election result in a change in control of the presidency, it is possible that a new administration could attempt to again expand the definition of “waters of the United States.” However, any serious regulatory expansion of Clean Water Act jurisdiction will require formal rulemaking and would likely face an uphill climb to being upheld by the current Supreme Court.

The Navigable Water Protection Rule will be in effect 60 days after it is published in the Federal Register.

¹ EPA, Navigable Waters Protection Rule, https://www.epa.gov/sites/production/files/2020-01/documents/navigable_waters_protection_rule_prepbulication.pdf.

² 80 Fed. Reg. 37053 (2015).

³ 51 Fed. Reg. 41217 (1986).

⁴ EPA, The Navigable Waters Protection Rule (Step Two) – Revise, https://www.epa.gov/nwpr/navigable-waters-protection-rule-step-two-revise.

5 EPA, Prepublication rule preamble, The Navigable Waters Protection Rule, https://www.epa.gov/sites/production/files/2020-01/documents/navigable_waters_protection_rule_prepbulication.pdf.