New WOTUS Definition Finalized – New Challenges Expected

On January 23, 2020, the U. S. Environmental Protection Agency (EPA) and the U. S. Army Corps of Engineers (Corps) pre-published the final Navigable Waters Protection Rule (NWP Rule), which (yet again) redefines the scope of waters that are regulated under the Clean Water Act (CWA).  In particular, the final NWP Rule revises the definition of “waters of the United States” (WOTUS) in 12 federal regulations and will become effective 60 days after publication in the Federal Register. Once effective, the NWP Rule will almost certainly be challenged in the courts by NGOs and other interested parties. These challenges could result in the courts staying the NWP Rule in some, or all, states while the lawsuits are litigated.

The NWP Rule is the final step in fulfilling the Trump administration’s promise to repeal and replace the Obama administration’s 2015 Clean Water Rule (CWR), which many believe improperly expanded the scope of waters regulated under the CWA. Effective December 23, 2019, EPA and the Corps repealed the CWR and restored the WOTUS definition that existed prior to 2015 (Pre-2015 Rule). Prior to the repeal, the Pre-2015 Rule’s WOTUS definition applied in approximately half of the states, while the CWR’s WOTUS definition applied in the remainder (including Pennsylvania), resulting in certain states having more federally regulated waters than other states.

The stated intent of the NWP Rule is to provide “clarity, predictability and consistency” regarding CWA jurisdiction. Consistent with the President’s February 28, 2017 Executive Order, the NWP Rule heavily reflects and relies upon Justice Antonin Scalia’s interpretation of the Pre-2015 Rule’s definition of WOTUS, as expressed in his plurality opinion in the seminal case, Rapanos v. United States (547 U.S. 715 (2006)). Missing from the NWP Rule is any reference to the significant nexus test discussed in Justice Anthony Kennedy’s concurring opinion in Rapanos.  As background, Justice Scalia opined that relatively permanent, standing, or continuously flowing waters and wetlands with a continuous surface connection to such relatively permanent waters should be regulated under the CWA, while Justice Kennedy advocated for CWA jurisdiction for wetlands with a significant nexus to a navigable water (i.e., a significant effect on the chemical, physical and biological integrity of traditional navigable water).

Scope of NWP Rule is Narrower and Clearer than Previous Rules

The NWP Rule consolidates jurisdictional waters into four categories: (1) territorial seas and navigable-in-fact waters; (2) tributaries; (3) lakes, ponds and impoundments of jurisdictional waters; and (4) adjacent wetlands.

As expected, the WOTUS definition in the NWP Rule is much narrower, and will federally regulate less waters, than would have been regulated under the CWR. The NWP Rule also provides more clarity as to the scope of WOTUS than the Pre-2015 Rule. The NWP Rule includes sixteen definitions and twelve exclusions, as compared to the five definitions and two exclusions in the Pre-2015 Rule, including, for the first time, definitions to clarify the prior converted cropland and waste treatment system exclusions. The NWP Rule categorically excludes, among other things, ephemeral streams and ditches without perennial or intermittent flow.

We note that, despite attempts to provide clarity, the NWP Rule still contains terms that may be subjectively interpreted. For example, the Rule relies on conditions in a “typical year” to determine whether a water meets the definition of an “adjacent wetland,” “lakes and ponds, and impoundments,” or a “tributary.” Subjectivity is likely in making these determinations because a “typical year” is defined by the “normal periodic range” of climatic conditions in a geographic area based on a rolling 30-year period.

Practical Impact of NWP Rule is Uncertain

While the NWP Rule is intended to clarify the scope of federally regulated waters, the practical impact of the Rule for industry, developers, agriculture and others is uncertain. The effect of the NWP Rule is likely less in states with very inclusive definitions of state waters than in states with narrower definitions of the same.

For example, under Pennsylvania’s Clean Streams Law, “waters of the Commonwealth” broadly include “any and all rivers, streams, creeks, rivulets, impoundments, ditches, water courses, storm sewers, lakes, dammed water, ponds, springs and all other bodies or channels of conveyance of surface and underground water, or parts thereof, whether natural or artificial, within or on the boundaries of this Commonwealth.” Pennsylvania’s definition of “waters of the Commonwealth” is generally more expansive (i.e., includes more types of waters) than the NWP Rule’s WOTUS definition. Therefore, projects that are expected to impact, or discharge into, a water of the Commonwealth will still (typically) require state permitting, even if federal permitting may not be required. In some instances, Corps permitting may not be needed for impacts to streams or wetlands that would require a state permit. There may also be implications, in limited circumstances, as to whether Spill Prevention, Control, and Countermeasure (SPCC) plans would be needed for certain facilities.

In states with definitions of state waters that are the same or less inclusive than the NWP Rule, the Rule is expected to be a more significant consideration on projects that require permitting or spill planning/response.

Controversy Continues and Challenges are Expected

While many in industry and agriculture have supported the NWP Rule, a number of NGOs and other interested parties have signaled that they will challenge the NWP Rule on procedural and substantive grounds. In addition, the EPA’s own Science Advisory Board, and other scientific organizations, have criticized the NWP Rule as being in conflict with established science and the objectives of the CWA. With legal challenges looming, the NWP Rule may be stayed in some, or all, states, with the Pre-2015 Rule remaining the definition of WOTUS nationwide or in select states.

EPA and the Corps will hold a public webcast on the NWP Rule on February 13, 2020. Interested parties can register for the webcast at Babst Calland has analyzed the evolution of the regulatory definition of WOTUS in numerous Environmental Alerts over the years (see and will continue to actively monitor this controversial regulatory issue. If you have questions about the NWP Rule or water-related matters in general, please contact Lisa M. Bruderly at (412) 394-6495 or

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