U.S. EPA Provides Guidance to Clarify Clean Water Act

In June of 2007, the EPA issued a Rapanos Guidance Memorandum to clarify Clean Water Act jurisdiction following the U.S. Supreme Court Decision in Rapanos v. United States & Carabell v. United States. Since Rapanos was a plurality decision, the EPA will apply the Scalia or Kennedy standards for determining Clean Water Act jurisdiction on a case-by-case basis. The Guidance prepared by the EPA indicates that its analysis will apply to CWA § 404 permits, but it may also apply to other permits that share the definition of “waters of the United States,” e.g., §§ 311 and 402 permits.

The Guidance summarizes its key points as follows:

The agencies will assert jurisdiction over the following waters:

• Traditional navigable waters
• Wetlands adjacent to traditional navigable waters
• Non-navigable tributaries of traditional navigable waters that are relatively permanent where the tributaries typically flow year-round or have continuous flow at least seasonally (e.g., typically three months)
• Wetlands that directly abut such tributaries

The agencies will decide jurisdiction over the following waters based on a fact-specific analysis to determine whether they have a significant nexus with a traditional navigable water:

• Non-navigable tributaries that are not relatively permanent
• Wetlands adjacent to non-navigable tributaries that are not relatively permanent
• Wetlands adjacent to but that do not directly abut a relatively permanent non-navigable tributary

The agencies generally will not assert jurisdiction over the following features:

• Swales or erosional features (e.g., gullies, small washes characterized by low volume, infrequent, or short duration flow)
• Ditches (including roadside ditches) excavated wholly in and draining only uplands and that do not carry a relatively permanent flow of water

The agencies will apply the significant nexus standard as follows:

• A significant nexus analysis will assess the flow characteristics and functions of the tributary itself and the functions performed by all wetlands adjacent to the tributary to determine if they significantly affect the chemical, physical and biological integrity of downstream traditional navigable waters
• Significant nexus includes consideration of hydrologic and ecologic factors