Transportation projects must also be compliant with the Clean Water Act (CWA). The CWA establishes the regulation of pollutant discharge into waters of the United States and regulates the standards for surface waters. The CWA has made it against the law to discharge any pollutant from a point source into navigable waters, unless a permit is obtained.
Section 404 of the CWA establishes a program to regulate the discharge of dredged or fill material into “waters of the United States,” including wetlands. Activities regulated under this program include fill for development, water resources projects, infrastructure development (transportation projects) and mining projects. A permit is required before dredged or fill material may be discharged into waters. As part of the application process, it must be shown that steps have been taken to avoid impacts to wetlands, steams and other aquatic resources, that potential impacts have been minimized and that compensation will be provided for all remaining unavoidable impacts. Wetland delineations and stream assessments are done to identify water bodies within a project’s boundaries the meet the definition of “waters of the United States.” If the US Army Corps of Engineers determines a wetland is a “water of the United States” it must be regulated under the CWA. Permits are reviewed by the US Army Corps of Engineers, and are evaluated under a public interest review as well environmental criteria.
If a Section 404 permit is received from the US Army Corps of Engineers, it is then required to obtain a Section 401 Water Quality Certification from the state regulatory agency. Issuance of this certifications shows that the project will comply with state water quality standards. The certification covers the construction, operation and maintenance of the project.
- Wetland Delineation: Wetland delineation establishes the existence and physical limits of a wetland. Once completed, a wetland boundary shall be clearly marked in the field, have a map that clearly identifies data collection points and the boundaries and have a report that explains how the boundary was determined.
- Stream Assessment: Stream assessments are done to analyze the condition of a stream that may be impacted. Items such as stream length, velocity, depth, sediment deposition, channel flow, bank stability and vegetative protection are all measured.
- Mitigation: The restoration, creation, enhancement, or preservation of a wetland, stream, or habitat area which offsets expected impacts to nearby ecosystems. The overall goal is to replace the exact function and value of the specific wetland habitats that would be adversely affected by a proposed project.