On Tuesday, March 25, 2014, the U.S. Environmental Protection Agency and the U.S. Army Corps of Engineers jointly announced a proposed rule to amend the regulatory definition of “waters of the United States,” which essentially governs the scope of federal jurisdiction under the Clean Water Act.  The proposed rule would redefine which areas are covered under regulations for all Clean Water Act programs, including sections 303 (water quality standards programs), 311 (oil spill prevention and response program), 401 (state water quality certification requirements), 402 (National Pollutant Discharge Elimination System (NPDES) permit program), and 404 (dredge and fill permitting).

The Agencies state in the preamble of the proposed rule that certain water bodies which, under current law, would have been deemed to be subject to federal jurisdiction only after a case-by-case determination, would be deemed to be jurisdictional waters by definition.  Specifically, under the proposed rule, waters of the United States would, by definition, include not only traditional navigable waters, interstate waters, territorial seas, and tributaries of those water bodies, but also waters and wetlands that are adjacent to those waters.^[1]  The proposed rule also includes several definitions central to the interpretation of the scope of the terms “tributary” and “adjacent.”

• As proposed, “tributary” means a water with a bed, banks and an ordinary high water mark, which contributes flow, either directly or through another water, to a navigable water, interstate water, territorial sea, or an impoundment of such waters.  Wetlands, lakes, and ponds would also fit within the definition (even those lacking a bed and banks or ordinary high water mark) if they contribute flow, either directly or through another water, to a navigable water, interstate water, or territorial sea.  The term would also encompass rivers, streams, lakes, ponds, impoundments, canals, and ditches, whether natural or man-made, unless a particular water body is specifically excluded, as discussed below.  The presence of one or more man-made breaks (such as a bridge, culvert, pipe, or dam) or natural breaks (such as wetlands at the head of or along the run a stream, debris piles, boulder fields, or a stream that flows underground) would not necessarily disqualify a water body from meeting the definition of a tributary so long as a bed and banks and ordinary high water mark can be identified upstream of the break.

• With regard to whether waters or wetlands are adjacent to other waters of the United States, the proposed rule retains the existing regulatory definition for “adjacent,” which means “bordering, contiguous or neighboring.”  The proposed rule, however, provides new definitions for related terms, including:

• “Neighboring,” which, for purposes of the term “adjacent”, is defined to include waters located within the “riparian area” or “floodplain” of a water of the United States or “waters with a shallow subsurface hydrologic connection or confined surface hydrologic connection to such a jurisdictional water.”

• “Riparian area” is defined to mean “area bordering a water where surface or subsurface hydrology directly influence the ecological processes and plant and animal community structure in that area. Riparian areas are transitional areas between aquatic and terrestrial ecosystems that influence the exchange of energy and materials between those ecosystems.”

• “Floodplain” is defined as “an area bordering inland or coastal waters that was formed by sediment deposition from such water under present climatic conditions and is inundated during periods of moderate to high water flows.”

While the inclusion of the newly defined terms would avoid the application of the current “significant nexus” test to determine whether tributaries or adjacent waters are subject to Clean Water Act jurisdiction, the foregoing definitions appear to leave considerable room for varying interpretations as to whether a given area’s hydrology could, for instance, “influence ecological processes” or even whether or not an area is inundated during periods of “moderate to high water flows.”

The proposed rule would also leave open the possibility that “other waters” might also come within federal jurisdiction if, upon a case specific determination, “those waters alone, or in combination with other similarly situated waters, including wetlands, located in the same region, have a significant nexus” to a traditional navigable water, interstate water, or territorial sea.

The proposed rule defines “significant nexus” to mean “that a water, including wetlands, either alone or in combination with other similarly situated waters in the region (i.e., the watershed that drains to the nearest [traditional navigable water, interstate water, or territorial sea]), significantly affects the chemical, physical, or biological integrity of a [traditional navigable water, interstate water, or territorial sea]. For an effect to be significant, it must be more than speculative or insubstantial. Other waters, including wetlands, are similarly situated when they perform similar functions and are located sufficiently close together or sufficiently close to a ‘water of the United States’ so that they can be evaluated as a single landscape unit with regard to their effect on the chemical, physical, or biological integrity of a [traditional navigable water, interstate water, or territorial sea].”

The proposed rule would specifically exclude the following from the definition of waters of the United States:

• 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 the purposes of the Clean Water Act, the final authority regarding Clean Water Act jurisdiction remains with EPA

• Ditches that are excavated wholly in uplands, drain only to uplands, and have less than perennial flow

• Ditches that do not contribute flow, either directly or through another water, to navigable waters, interstate waters, territorial seas, or impoundments of such waters

Certain other water features:

• Artificially irrigated areas that would revert to upland should application of irrigation water to that area cease

• 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

• Artificial reflecting pools or swimming pools created by excavating and/or diking dry land

• Small ornamental waters created by excavating and/or diking dry land for primary aesthetic reasons

• Water-filled depressions created incidental to construction activity

• Groundwater, including groundwater drained through subsurface drainage systems

• Gullies and rills and non-wetland swales

Exemptions contained elsewhere in the Clean Water Act (such as those related to farming) would still apply, even if a particular water body would otherwise meet the definition of a water of the United States as proposed.

Comments on the proposed rule will be due 90 days from the date it is published in the Federal Register, which should occur soon.

_{[1] Interpreting Justice Kennedy’s concurring opinion in Rapanos v. United States, 547 U.S. 715 (2006), the Agencies have since applied the “significant nexus” test to determine whether adjacent wetlands or tributaries are subject to Clean Water Act jurisdiction on a case-by-case basis.  See Proposed Rule, to be published in the Federal Register and on Regulations.gov in  Docket No. EPA-HQ-OW-2011-0880, prepublication version at 18.}