Outfall

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.[1]

United States permit requirements

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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]

See also

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References

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  1. ^ "Structure: Outfall". Bristol, UK: United Kingdom Department for Environment Food & Rural Affairs. 2025-04-06.
  2. ^ United States. Pub. L. 92–500: Federal Water Pollution Control Act Amendments of 1972 Approved October 18, 1972.
  3. ^ "National Pollutant Discharge Elimination System". Washington, D.C.: U.S. Environmental Protection Agency (EPA). 2025-06-03.
  4. ^ "NPDES Permit Basics". EPA. 2025-06-03.