The Clean Water Act (CWA) provides federal agencies with authority to regulate a wide range of activities that may affect “waters of the United States”—sometimes called “navigable waters.” These activities include water quality planning and discharge regulation by the 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.
How Have the Definitions Evolved?
CWA does not provide a statutory definition of the waters it covers, and CWA Section 502 defines “navigable waters” as “waters of the United States, including territorial seas.” This vague and circular definition has left agencies and courts to decide which waters are covered, and therefore which CWA programs apply. Not surprisingly, EPA and the Corps established expansive interpretations, which for decades allowed them to regulate a wide range of activities. The US Supreme Court upended these interpretations in a series of decisions beginning in 2001. 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 (in a 4-4-1 fragmented opinion with Justice Kennedy’s opinion the effective decision of the Court) ruled in 2006 that the Corps can exert 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”).
These Supreme Court decisions led the agencies to evaluate their jurisdiction over waters on a case-specific basis far more frequently, complicating their regulatory programs. To attempt to clarify and streamline regulation, on March 25 they have jointly proposed a definition that incorporates the Supreme Court’s guidance. The central provision of this 370 page document is the following definition:
(a) For purposes of all sections of [CWA] and its implementing regulations, subject to the exclusions in paragraph (b) of this section, the term “waters of the United States” means:
- 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.
- All interstate waters, including interstate wetlands.
- The territorial seas.
- All impoundments of waters identified in paragraphs (a)(1) through (3) and (5) of this section.
- All tributaries of waters identified in paragraphs (a)(1) through (4) of this section.
- All waters, including wetlands, adjacent to a water identified in paragraphs (a)(1) through (5) of this section.
- On a case-specific basis, other waters, including wetlands, provided that those waters alone, or in combination with other similarly situated waters, including wetlands, located in the same region, have a significant nexus to a water identified in paragraphs (a)(1) through (3) of this section.
(b) The following are not “waters of the United States” notwithstanding whether they meet the terms of paragraphs (a)(1) through (7) of this section ??
- Waste treatment systems, including treatment ponds or lagoons, designed to meet the requirements of the Clean Water Act.
- Prior converted cropland. Notwithstanding the determination of an area’s status as prior converted cropland by any other federal agency, for [CWA purposes] the final authority regarding Clean Water Act jurisdiction remains with EPA.
- Ditches that are excavated wholly in uplands, drain only uplands, and have less than perennial flow.
- Ditches that do not contribute flow, either directly or through another water, to a water identified in paragraphs (a)(1) through (4) of this section.
- The following features:
(i) Artificially irrigated areas that would revert to upland should application of irrigation water to that area cease. (ii) Artificial lakes or ponds created by excavating and/or diking dry land and used exclusively for such purposes as stock watering, irrigation, settling basins, or rice growing. (iii) Artificial reflecting pools or swimming pools created by excavating and/or diking dry land. (iv) Small ornamental waters created by excavating and/or diking dry land for primarily aesthetic reasons. (v) Water-filled depressions created incidental to construction activity. (vi) Groundwater, including groundwater drained through subsurface drainage systems. (vii) Gullies and rills and non-wetland swales.