Section 404 of the Clean Water Act (CWA) establishes a program to regulate the discharge of dredged or fill material into waters of the United States, including wetlands. Activities in waters of the United States regulated under this program include fill for development, water resource projects (such as dams and levees), infrastructure development (such as highways and airports) and mining projects.

Proposed activities are regulated through a permit review process. In reviewing Corps public notices, EPA gives greatest attention to projects that will have unacceptable impacts to Aquatic Resources of National Importance, as described in the 1992 MOA for Resolving Disputes between EPA and the Corps.