On January 18, 2023, the US Environmental Protection Agency (EPA) and US Army Corps of Engineers (Corps) adopted revised definitions of “waters of the United States.” The Clean Water Act (CWA) empowers federal agencies to regulate activities that may affect “waters of the United States”—sometimes called “navigable waters.” These activities include water quality planning and discharge regulation by EPA and delegated states, and regulation of projects that may lead to “dredge and fill” of waters, requiring permits from the Corps. The remainder of this note offers a brief summary of the last 20 years of judicial reinterpretations and regulatory responses, and discusses the latest revisions.
How have the definitions been questioned in recent years?
CWA does not define this critical term. EPA and the Corps adopted regulatory definitions in 1986, which included ambiguities that increased agency discretion but sometimes frustrated landowner aspirations. After many years of regulatory stability, beginning in 2001 a series of US Supreme Court decisions frayed the expansive edges of the regulators’ traditional interpretations. 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 in 2006 that the Corps can jurisdiction over non-adjacent wetlands extends only where there is a “significant nexus” between “relatively permanent” wetlands and navigable waters.
These cases triggered a series of rulemakings through which EPA and the Corps have sought to define CWA terms in ways that reconcile Supreme Court with the agencies’ policy preferences … as those preferences have varied during the Obama, Trump, and now Biden administrations. Obama and Trump era revisions were stayed by litigation (I discussed the Obama era revisions HERE, and the superseding Trump era revisions HERE). Since President Biden assumed office, the agencies have administered their authority applying the pre-2015 definitions. In November 2021 EPA and the Corps proposed definitions to suit Biden Administration priorities, reaffirming the pre-2015 definitions with some adjustments (I wrote about that proposal HERE).
What definitions are provided by the latest proposal?
The agencies are now adopting the following definitions (in 33 CFR 328.3 and 40 CFR 120.1), which generally are consistent with those proposed in 2021:
- Waters of the United States
“[40 CFR 120.1(a)] Waters of the United States means:
- Waters which are:
- Currently used, or 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;
- The territorial seas; or
- Interstate waters, including interstate wetlands;
- Impoundments of waters otherwise defined as waters of the United States under this definition, other than impoundments of waters identified under paragraph (a)(5) of this section;
- Tributaries of waters identified in paragraph (a)(1) or (2) of this section:
- That are relatively permanent, standing or continuously flowing bodies of water; or
- That either alone or in combination with similarly situated waters in the region, significantly affect the chemical, physical, or biological integrity of waters identified in paragraph (a)(1) of this section;
- Wetlands adjacent to the following waters:
- Waters identified in paragraph (a)(1) of this section; or
- Relatively permanent, standing or continuously flowing bodies of water identified in paragraph (a)(2) or (a)(3)(i) of this section and with a continuous surface connection to those waters; or
- Waters identified in paragraph (a)(2) or (3) of this section when the wetlands either alone or in combination with similarly situated waters in the region, significantly affect the chemical, physical, or biological integrity of waters identified in paragraph (a)(1) of this section;
- Intrastate lakes and ponds, streams, or wetlands not identified in paragraphs (a)(1) through (4) of this section:
- That are relatively permanent, standing or continuously flowing bodies of water with a continuous surface connection to the waters identified in paragraph (a)(1) or (a)(3)(i) of this section; or
- That either alone or in combination with similarly situated waters in the region, significantly affect the chemical, physical, or biological integrity of waters identified in paragraph (a)(1) of this section.
However, the definition provides exclusions, under which the following are not “waters of the United States” even where they otherwise meet the terms above:
- Waste treatment systems, including treatment ponds or lagoons, designed to meet the requirements of the Clean Water Act;
- Prior converted cropland designated by the Secretary of Agriculture. The exclusion would cease upon a change of use, which means that the area is no longer available for the production of agricultural commodities. Notwithstanding the determination of an area’s status as prior converted cropland by any other Federal agency, for the purposes of the Clean Water Act, the final authority regarding Clean Water Act jurisdiction remains with EPA;
- Ditches (including roadside ditches) excavated wholly in and draining only dry land and that do not carry a relatively permanent flow of water;
- Artificially irrigated areas that would revert to dry land if the irrigation ceased;
- Artificial lakes or ponds created by excavating or diking dry land to collect and retain water and which are used exclusively for such purposes as stock watering, irrigation, settling basins, or rice growing;
- Artificial reflecting or swimming pools or other small ornamental bodies of water created by excavating or diking dry land to retain water for primarily aesthetic reasons;
- Waterfilled depressions created in dry land incidental to construction activity and pits excavated in dry land for the purpose of obtaining fill, sand, or gravel unless and until the construction or excavation operation is abandoned and the resulting body of water meets the definition of waters of the United States; and
- Swales and erosional features (e.g., gullies, small washes) characterized by low volume, infrequent, or short duration flow
“Wetlands means those areas that are inundated or saturated by surface or ground water 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. Wetlands generally include swamps, marshes, bogs, and similar areas.”
This definition attempts to define wetlands based on hydrology and associated lifeforms.
- “Significantly affect”
“Significantly affect means a material influence on the chemical, physical, or biological integrity of waters identified in paragraph (a)(1) of this section. To determine whether waters, either alone or in combination with similarly situated waters in the region, have a material influence on the chemical, physical, or biological integrity of waters identified in paragraph (a)(1) of this section, the functions identified in paragraph (c)(6)(i) of this section will be assessed and the factors identified in paragraph (c)(6)(ii) of this section will be considered:
- Functions to be assessed:
- Contribution of flow;
- Trapping, transformation, filtering, and transport of materials (including nutrients, sediment, and other pollutants);
- Retention and attenuation of floodwaters and runoff;
- Modulation of temperature in waters identified in paragraph (a)(1) of this section; or
- Provision of habitat and food resources for aquatic species located in waters identified in paragraph (a)(1) of this section;
- Factors to be considered:
- The distance from a water identified in paragraph (a)(1) of this section;
- Hydrologic factors, such as the frequency, duration, magnitude, timing, and rate of hydrologic connections, including shallow subsurface flow;
- The size, density, or number of waters that have been determined to be similarly situated;
- Landscape position and geomorphology; and
- Climatological variables such as temperature, rainfall, and snowpack.
This definition leaves regulators to make case-by-case determination, which is consistent with the ambiguous guidance from the Supreme Court. It supports traditional approaches in which upstream waters that might not qualify as waters of the US on their own are regulated as such because contamination or degradation would be expected to flow downstream to harm waters that do qualify on their own.
The revised rules will become effective on March 20, 2023, 60 days after publication in the Federal Register. After that the agencies will begin to enforce the final … and we will all await the inevitable litigation.
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 the previous definitions?
- Under the new definitions?
Has my organization evaluated requirements under state laws in each state in which activities may affect water bodies or wetlands?
Where can I go for more information?
- Proposed rule (1/18/23 Federal Register)
- EPA webpage ‘Revising the Definition of “Waters of the United States”
About the Author
Jon Elliott is President of Touchstone Environmental and has been a major contributor to STP’s product range for over 30 years.
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: firstname.lastname@example.org