Title: Definition of “waters of the United States” – Recodification of Pre-existing rules

Docket ID: CEO-2017-0005

Agency: EPA, DOD - Army Corps of Engineers

Comments Close: September 27, 2017 (extended from August 28, 2017)



Summary Index (select section title to go to section)

  1. Purpose
  2. Notice Details 
  3. Context: (1) Definition of "waters of the United States" and the Clean Water Act, (2) Evolution of the current definition through relevant court cases, (3) The Clean Water Rule.




In 2015, the Environmental Protection Agency and the Department of the Army published the Clean Water Rule: Definition of `Waters of the United States'. The agencies now propose to replace the 2015 definition of “waters of the United States”, and reinstate the definition of "waters of the United States" 'that existed prior to the 2015 rule, to reflect the current legal regime under which the agencies are operating.' This is in compliance with the February 28, 2017 Executive Order “Restoring the Rule of Law, Federalism, and Economic Growth by Reviewing the `Waters of the United States' Rule.”Changing the definition of "waters of the United States" changes the waters which fall under the provisions of the Clean Water Act. 





'In this proposed rule, the agencies would rescind the 2015 Clean Water Rule,' and replace it with the definition of "waters of the United States" used prior to the Clean Water Rule. This is the definition currently being implemented by the EPA and the Army Corps of Engineers. 

While the proposal merely establishes a definition, and not any regulatory requirements or mandated actions, 'by changing the definition of “waters of the United States,” the proposed rule would change the waters where other regulatory requirements ...come into play,' such as when a permit would be required to dump waste into a certain body of water. 'The consequence of a water being deemed non-jurisdictional is simply that [Clean Water Act] provisions no longer apply to that water.'

In the text, the agencies note that 'a decision to rescind and revise the regulatory definition of the "waters of the United States" need not be based upon a change of facts or circumstances. A revised rulemaking based “on a re-evaluation of which policy would be better in light of the facts” is “well within an agency's discretion,” and “[a] change in administration brought about by the people casting their votes is a perfectly reasonable basis for an executive agency's reappraisal” of its regulations and programs.'

'Nothing in this proposed rule restricts the ability of States to protect waters within their boundaries by defining the scope of waters regulated under State law more broadly than the federal law definition.'





The legal definition for “waters of the United States” greatly impacts how the Environmental Protection Agency (EPA) implements the Clean Water Act. The Clean Water Act, or CWA, was established to prevent, reduce, and eliminate pollution in the nation’s water in order to “restore and maintain the chemical, physical, and biological integrity of the Nation’s waters” and to eliminate discharge of pollutants in “navigable waters” (section 101(a); section 502(7)). Additionally, the CWA establishes permit systems, programs, and standards, to meet its defined goals, among which includes the dredge or fill discharge permit program (section 404(a)). This program prohibits any discharge of dredged or fill materials into “navigable waters”, defined as “waters of the United States”, unless authorized by a permit issued by the Army Corps of Engineers.

How "waters of the United States" is defined directly effects "the scope of CWA jurisdiction, [which] is an issue of great national importance." This definition has changed several times since the CWA was established.


Evolution of the current definition of "waters of the United States"

Congressional Research Service

U.S. v. Riverside Bayview Homes 1985

The US Army Corps of Engineers issued a regulation to interpret the dredge or fill discharge permit program of the CWA to include “adjacent wetlands” as waters of the United States, and defined “adjacent wetlands” as “those areas that are inundated or saturated by surface or groundwater at a frequency and duration sufficient to support, and that under normal circumstances do support a prevalence of vegetation typically adapted for life in saturated soil conditions”.

 This expansion of the “waters of the United States” was upheld by the Supreme Court in a 1985 court case. Bayview Homes, Inc. began placing fill materials on its property near Lake St. Clair, Michigan and the Corps issued a suit to prevent Bayview Homes from filling its property without applying for the required permit.

Ultimately, the Supreme Court deferred to the Corps’ judgment that adjacent wetlands are “inseparably bound up” with waters to which they are adjacent, and upheld the inclusion of adjacent wetlands in the regulatory definition of “waters of the United States”.

 Solid Waste Agency of Northern Cook County v. U.S. Army Corps of Engineers (SWANCC) 2001

In 1986, the Army Corps of Engineers attempted to clarify its jurisdiction stating that the definition of “waters of the United States” extends to intrastate waters that provide habitat for migratory birds, as migratory birds are a form of interstate commerce. This was dubbed the “Migratory Bird Rule” (FRL-7439-9). Ultimately, the Supreme Court ruled the use of ‘isolated’ non-navigable intra-state ponds by migratory birds was an insufficient basis for federal regulation. This decision did not call into question previous rulings for wetlands ‘adjacent’ to navigable waterways, but did introduced a concept that it is a ‘significant nexus’ which informs the Courts reading of the CWA jurisdiction over non-navigable waters.

 This ruling came from a court case following the Solid Waste Agency of Northern Cook County selection of an abandoned sand and gravel pit as a solid waste disposal site. This pit, after being unused for a long period, had evolved into permanent and seasonal ponds. The operation required some of the ponds to be filled, which required a landfill permit from the Army Corps of Engineers. The Corps refused to issue the permit on the basis of the Migratory Bird Rule. Even though lower courts had sustained the Rule for the 15 years since the Rule was implemented, this case went to the Supreme Court, which threw out the Rule.

 Rapanos v. United States (Rapanos) 2006

In 1989 the petitioner, John A. Rapanos, backfilled wetlands on a parcel of land he owned and sought to develop in Michigan. The parcel included land with sometimes-saturated conditions, though the nearest navigable water body was 11 to 20 miles away. Rapanos was informed his land included ‘waters of the United States’ even though they were not navigable waterways.

It was determined that a critical factor in the CWA’s coverage is whether the water has ‘significant nexus’ to downstream ‘traditional navigable waters’ – in other words, is the water important to protecting the chemical, physical, or biological integrity of navigable waters? A guidance was issued in 2008 by the EPA and Corps for clarification, but the agencies did not officially change or codify the definition.


The Clean Water Rule

The EPA and the Corps were ask to replace the 2008 guidance (above) with a regulation to provide more clarity by a range of organizations, including Congress, developers, farmers, state and local governments, environmental organizations, and energy companies. The agencies published a final rule defining the scope of the “waters of the United States” protected under the CWA: the 2015 Clean Water Rule: Definition of “Waters of the United States”The definition established in this rule incorporated the Supreme Court Decisions of Riverside, SWANCC, and Rapanos, in addition to agencies’ experience, expertise, scientific review, and public comment periods.

The 2015 Clean Water Rule established eight types of waterways and the extent of the legal power to regulate those waters under the CWA.

“Waters of the United States,” regulated under the CWA:


  • Traditional navigable waterways, interstate waters, and impoundments of jurisdictional waters
  • Other waterways which have a “significant nexus” to navigable waters, interstate waters, or territorial seas. This includes: (1) tributaries, (2) adjacent waters that are “bordering, contiguous, or neighboring” navigable waterways, interstate waters, and impoundments, (3) adjacent waters separated by constructed dikes, barriers, natural river berms, and beach dunes.”  
  • Streams that are “intermittent, ephemeral, or headwaters”

Not “Waters of the United States”: Waters that are not classified as navigable waterways, interstate waters, impoundments, tributaries, or adjacent waters, which includes:

  • Converted cropland
  • Waste treatment systems
  • Ditches that are not modified tributaries
  • Groundwater
  • Erosional features

This rule also established a "significant nexus" standard which allows agencies to interpret the scope of the “waters of the United States” if the waters in question significantly affect the chemical, physical, or biological integrity of traditional navigable waters, interstates waters, or territorial seas - either alone, or in combination with similarly situated waters in the region. So any of the excluded waters above are subject to a case-specific analysis to determine if a "significant nexus" exists, and if it does, that specific water body is regulated under the Clean Water Rule. 


Stay of the Clean Water Rule by the Sixth Circuit Court

After publication of the final Clean Water Rule, thirteen States and additional parties sought judicial review about the Rule’s scope and legal authority. In State of North Dakota et al. v. US EPA the Sixth Circuit court of appeals paused the implementation of the Clean Water Rule until the Supreme Court could hear the case and make a decision on its legality. As of August 2017, the EPA and the Corps use the pre-Clean Water Rule definition of “waters of the United States” to implement the Clean Water Act.


Review of the Clean Water Rule by Executive Order

An executive order was issued on February 28, 2017 (Presidential Executive Order on Restoring the Rule of Law, Federalism, and Economic Growth by Reviewing the “Waters of the United States” Rule) which called for a review of the 2015 Clean Water Rule by the Administrator of the EPA and Assistant Secretary of the Army for Civil Works to ensure “the Nation’s navigable waters are kept free from pollution, while at the same time promoting economic growth, minimizing regulatory uncertainty, and showing due regard for the roles of Congress” and to rescind or revise any rules, orders, regulations, guidelines, or policies that do not comply with these goals. Additionally, it states the definition of “navigable waters” will be interpreted as defined by 33 U.S.C. 1362(7) “in a manner consistent with Justice Antonin Scalia in Rapanos v. United States, 547 U.S. 715 (2006),” who expressed concern over the Corps' broadening of the definition of "waters of the United States" as regulatory overreach. 




Contributor: MS Student, Aquatic and Fishery Sciences