Outfall

An outfall is the discharge point of a storm drain or waste stream into a body of water. In the United Kingdom, the term may also apply to discharges from a "watercourse", which may be a river, stream or canal.^[1]

Outfall with a flap valve at River Thames in London

United States permit requirements

Outfall from a sewage plant discharging to Passaic River in New Jersey

In the United States, point sources may not discharge pollutants to surface waters without a permit issued through the National Pollutant Discharge Elimination System (NPDES), as required by the Clean Water Act.^[2] Most NPDES permits are issued by state environmental agencies. The U.S. Environmental Protection Agency (EPA) issues permits in some locations.^[3]

Point sources include industrial facilities; service industries; municipal governments (particularly sewage treatment plants and stormwater outfalls); other government facilities such as military bases; and some agricultural facilities, such as animal feedlots.^[4]

Further information: United States regulation of point source water pollution

See also

• Combined sewer
• Greywater
• Marine outfall
• Night soil
• River mouth