Effluent

Effluent is wastewater from sewers or industrial outfalls that flows directly into surface waters, either untreated or after being treated at a facility.

[2] Effluent is defined by the United States Environmental Protection Agency (EPA) as "wastewater–treated or untreated–that flows out of a treatment plant, sewer, or industrial outfall.

[1] The Compact Oxford English Dictionary defines effluent as "liquid waste or sewage discharged into a river or the sea".

[7] Effluent in the artificial sense is in general considered to be water pollution, such as the outflow from a sewage treatment facility or an industrial wastewater discharge.

[10] Effluent may carry pollutants such as fats, oils and greases; solvents, detergents and other chemicals; heavy metal; other solids; and food waste.

Treating wastewater efficiently is challenging, but improved technology allows for enhanced removal of specific materials, increased re-use of water, and energy production from waste.