Pipelines extending into coastal and ocean waters that are used by various industries and municipal wastewater treatment facilities to discharge treated effluent. Some may be simple pipes serving as conveyances from land-based facilities; others include diffusers that help to rapidly dilute effluent or risers that ensure effluent is discharged at a certain height above the ocean floor. The conveyances may extend more than three miles (5 km) offshore, beyond coastal waters into open ocean. Offshore oil and gas exploration, development, and production rigs also possess ocean outfalls. Discharges from these pipes must be permitted under the Clean Water Act national pollutant discharge elimination system.

See Also

Sewage Treatment