Audit, Compliance and Risk Blog

EPA and Corps of Engineers (Re)define “Waters of the United States”

Posted by Jon Elliott on Tue, Jun 23, 2015 Clean Water Act (CWA) governs activities that may affect “waters of the United States” – sometimes called “navigable waters.” These activities include water quality planning and discharge regulation by the US Environmental Protection Agency (EPA) and delegated states, and regulation of projects that may lead to “dredge and fill” of waters, through permits issued by the US Army Corps of Engineers. However, CWA provides no definition of this critical term, leaving agencies and courts to define and apply the term, and thereby to define their authority to control actions that affect water quality. In 2001, and again in 2006, the U.S. Supreme Court issued decisions upending decades of established practice by eliminating some types of water bodies from CWA control, and casting others into ambiguous status. First, in Solid Waste Agency of Northern Cook County v. U.S. Army Corps of Engineers [SWANCC], the Court ruled that the Corps lacks jurisdiction over “isolated” waters and wetlands that are not “adjacent” to navigable waters—such as “prairie potholes,” mudflats, and freshwater seasonal ponds. Then, in Rapanos v. United States, the Court ruled that the Corps has jurisdiction over non-adjacent wetlands when it can demonstrate on a case-by-case basis that there is a “significant nexus” between the wetlands and navigable waters (in addition, opinions signed by eight of the justices required that the wetlands be at least “relatively permanent.”).

For the last decade, EPA and the Corps have worked to parse those ambiguities and re-establish predictable controls over water-affecting actions. In March 2014, the agencies proposed a revised regulation to do so (which I blogged about here). After another round of comments—in which active public outreach by EPA garnered over one millioncomments (and Congressional ire over what governing Republicans call “lobbying”) – the agencies have just announced a final rule. This rule makes further adjustments to last year’s draft. The key revised definition will now be 40 CFR section 230.3(s)(1)-(2):

“(1) [T]he term ‘waters of the United States’ means:

(i) All waters which are currently used, were used in the past, or may be susceptible to use in interstate or foreign commerce, including all waters which are subject to the ebb and flow of the tide.

(ii) All interstate waters, including interstate wetlands.

(iii) The territorial seas.

(iv) All impoundments of waters otherwise identified as waters of the United States under this section.

(v) All tributaries […]of waters identified in paragraphs (1)(i) through (iii).

(vi) All waters adjacent to a water identified in paragraphs (1)(i) through (v) …, including wetlands, ponds, lakes, oxbows, impoundments, and similar waters.

(vii) [Prairie potholes, Carolina bays or Delmarva bays, pocosins, western vernal pools, and Texas coastal prairie wetlands.] The[se] waters … are similarly situated and shall be combined, for purposes of a significant nexus analysis, in the watershed that drains to the nearest water identified in paragraphs (1)(i) through (iii) of this section. Waters identified in this paragraph shall not be combined with waters identified in paragraph (1).

(vi) of this section when performing a significant nexus analysis. If waters identified in this paragraph are also an adjacent water under paragraph (1)(vi), they are an adjacent water and no case-specific significant nexus analysis is required.

“(2) The following are not ‘waters of the United States’ even where they otherwise meet the terms of paragraphs (1)(iv) through (viii) of this section.

(i) Waste treatment systems, including treatment ponds or lagoons designed to meet the requirements of the Clean Water Act.

(ii) Prior converted cropland [as determined by EPA for CWA purposes].

(iii) [specified intermittent and agricultural ditches]:

(iv) The following features:

(A) Artificially irrigated areas that would revert to dry land should application of water to that area cease.
(B) Artificial, constructed lakes and ponds created in dry land such as farm and stock watering ponds, irrigation ponds, settling basins, fields flooded for rice growing, log cleaning ponds, or cooling ponds.
(C) Artificial reflecting pools or swimming pools created in dry land.
(D) Small ornamental waters created in dry land.
(E) Water-filled depressions created in dry land incidental to mining or construction activity, including pits excavated for obtaining fill, sand, or gravel that fill with water.
(F) Erosional features, including gullies, rills, and other ephemeral features that do not meet the definition of tributary, non-wetland swales, and lawfully constructed grassed waterways.
(G) Puddles.”

In this definition, EPA and the Corps are reaffirming the broadest definition that the courts’ allow. These include all “navigable” and interstate waters, and most natural waterways and water bodies connected to them – which the Supreme Court has said can be regulated using “Commerce Clause” powers from the US Constitution. They exclude isolated and single-state waters without sufficient “nexus” to such waters.

The agencies have scheduled this rule to become effective 60 days after publication in the Federal Register, so interested readers should watch for that publication. Practitioners will find that this complication will still lead to multi-step evaluations at many locations, as definitions are applied … first by would-be developers and then by preservationists and regulators.

Self-Assessment Checklist

Does my organization routinely discharge wastewaters:

  • Into a natural water body?

  • Into an artificial conveyance (ditch, storm sewer, etc.)?

  • Into a sanitary sewer system?

Does my organization operate a facility where rainwater or snowmelt might flow:

  • Into a natural water body?

  • Into an artificial conveyance (ditch, storm sewer, etc.)?

Is my organization undertaking a construction or other project that disturbs a waterway, or disturbs soil or rock that might contaminate runoff into a waterway?

Has my organization evaluated the receiving waters to determine whether they qualify as “waters of the United States” subject to CWA requirements?

    • Under existing regulations and permits?

    • Under the definitions included in the May 2015 regulation?

Where Can I Go For More Information?

Specialty Technical Publishers (STP) provides a variety of single-law and multi-law services, intended to facilitate clients’ understanding of and compliance with requirements. These include:

Subscribe to the STP Blog

 About the Author Elliott is President of Touchstone Environmental and has been a major contributor to STP’s product range for over 25 years. He was involved in developing 12 existing products, including Environmental Compliance: A Simplified National Guide and The Complete Guide to Environmental Law.

Mr. Elliott has a diverse educational background. In addition to his Juris Doctor (University of California, Boalt Hall School of Law, 1981), he holds a Master of Public Policy (Goldman School of Public Policy [GSPP], UC Berkeley, 1980), and a Bachelor of Science in Mechanical Engineering (Princeton University, 1977).

Mr. Elliott is active in professional and community organizations. In addition, he is a past chairman of the Board of Directors of the GSPP Alumni Association, and past member of the Executive Committee of the State Bar of California's Environmental Law Section (including past chair of its Legislative Committee).

You may contact Mr. Elliott directly at:

photo credit: crater lake national park 7 via photopin (license)