{{Short description|Discharge point of a drain or waste stream into a body of water}} {{Globalise|date=December 2025}} [[File:Bell Wharf CSO outfall in London.jpg|thumb|Outfall with a flap valve at River Thames in London]] 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.<ref>{{cite web |title=Structure: Outfall |url=https://environment.data.gov.uk/asset-management/drl-app/revision/current/categories/Structure/asset-types/Outfall |publisher=United Kingdom Department for Environment Food & Rural Affairs |date=2025-04-06 |location=Bristol, UK}}</ref>
== United States permit requirements == [[File:FlorhamParkSewerageUtilityOutfall.webm|thumb|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.<ref>United States. {{USPL|92|500|Federal Water Pollution Control Act Amendments of 1972}} Approved October 18, 1972.</ref> Most NPDES permits are issued by state environmental agencies. The U.S. Environmental Protection Agency (EPA) issues permits in some locations.<ref>{{cite web |title=National Pollutant Discharge Elimination System |url=https://www.epa.gov/npdes |date=2025-06-03 |publisher=U.S. Environmental Protection Agency (EPA) |location=Washington, D.C.}}</ref>
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.<ref>{{cite web |title=NPDES Permit Basics |url=https://www.epa.gov/npdes/npdes-permit-basics |date=2025-06-03 |publisher=EPA}}</ref> {{Further|United States regulation of point source water pollution}}
== See also == * Combined sewer * Greywater * Marine outfall * Night soil * River mouth
== References == {{Reflist}}
{{Sewerage}}
Category:Sewerage infrastructure Category:Water pollution