Section 404 permits are obtained from the USACE for projects that require fill material in jurisdictional waters of the U.S.
- General Permit (GP) - The SCDOT maintains a GP that authorizes the discharge of dredge and/or fill material in waters of the U.S. for the construction, expansion, modification, or improvement of existing linear transportation projects. Impacts cannot exceed 3.0 acres of freshwater wetlands, 0.5 acres of tidal wetlands, or 300 linear feet of stream. Section 401 Water Quality Certification is part of the GP.
- Nationwide Permit (NWP) - The most common NWPs used by SCDOT are the NWP 3 for maintenance and the NWP 14 for linear transportation projects. The NWP authorizes up to 0.5 acres of fill in freshwaters, 0.3 acres in tidal waters, and 300 linear feet in streams. Section 401 Water Quality Certification is part of the NWP.
- Individual Permits (IPs) - Required for projects that do not fall under a NWP or GP. IPs have a public notice component and are awarded based on the outcome of a public interest balancing process where the benefits of the project are balanced against the detriments. Section 401 Water Quality Certification is a separate process (through SCDHEC) for IPs.