33 C.F.R. § 385.14
(a) General.
(b) Actions normally requiring an Environmental Impact Statement (EIS).
(1) In addition to the actions listed in § 230.6 of this chapter, actions normally requiring an EIS are:
(d) Categorical exclusions. In addition to the activities listed in § 230.9 of this chapter, the following actions do not require separate NEPA documentation, either because, when considered individually and cumulatively, they do not have significant effects on the quality of the human environment or because any such effects will already have been considered in NEPA documentation prepared in accordance with paragraphs (b) and (c) of this section. However, the District Engineer should be alert for extraordinary circumstances that may dictate the need to prepare an EA or an EIS. Even though an EA or EIS is not indicated for a Federal action because of a “categorical exclusion,” that fact does not exempt the action from compliance with any other applicable Federal, State, or Tribal law, including but not limited to, the Endangered Species Act, the Fish and Wildlife Coordination Act, the National Historic Preservation Act, the Clean Water Act, Clean Air Act, the Coastal Zone Management Act, and the Marine Mammal Protection Act.