wastewater

{{Short description|Water that has been used and contaminated}}

{{distinguish|Wastwater}}

{{Pollution sidebar}}

Wastewater (or waste water) is water generated after the use of freshwater, raw water, drinking water or saline water in a variety of deliberate applications or processes.{{Cite book|url=https://www.worldcat.org/oclc/48053912|title=Wastewater engineering : treatment and reuse|date=2003|publisher=McGraw-Hill|first1=George |last1=Tchobanoglous |first2=Franklin L. |last2=Burton |first3=H. David |last3=Stensel |last4=Metcalf & Eddy|isbn=0-07-041878-0|edition=4th|location=Boston|oclc=48053912}}{{rp|1}} Another definition of wastewater is "Used water from any combination of domestic, industrial, commercial or agricultural activities, surface runoff / storm water, and any sewer inflow or sewer infiltration".{{cite book|last=Tilley|first=E.|last2=Ulrich|first2=L.|last3=Lüthi|first3=C.|last4=Reymond|first4=Ph.|last5=Zurbrügg|first5=C.|url=http://www.eawag.ch/en/department/sandec/publications/compendium/|title=Compendium of Sanitation Systems and Technologies –|publisher=Swiss Federal Institute of Aquatic Science and Technology (Eawag), Duebendorf, Switzerland|year=2014|isbn=978-3-906484-57-0|edition=2nd Revised|archive-url=https://web.archive.org/web/20160408021403/http://www.eawag.ch/en/department/sandec/publications/compendium/|archive-date=8 April 2016|url-status=live|df=dmy-all}}{{rp|175}} In everyday usage, wastewater is commonly a synonym for sewage (also called domestic wastewater or municipal wastewater), which is wastewater that is produced by a community of people.

As a generic term, wastewater may also describe water containing contaminants accumulated in other settings, such as:

• Industrial wastewater: waterborne waste generated from a variety of industrial processes, such as manufacturing operations, mineral extraction, power generation, or water and wastewater treatment.
• Cooling water, is released with potential thermal pollution after use to condense steam or reduce machinery temperatures by conduction or evaporation.
• Leachate: precipitation containing pollutants dissolved while percolating through ores, raw materials, products, or solid waste.
• Return flow: the flow of water carrying suspended soil, pesticide residues, or dissolved minerals and nutrients from irrigated cropland.
• Surface runoff: the flow of water occurring on the ground surface when excess rainwater, stormwater, meltwater, or other sources, can no longer sufficiently rapidly infiltrate the soil.
• Urban runoff, including water used for outdoor cleaning activity and landscape irrigation in densely populated areas created by urbanization.
• Agricultural wastewater: animal husbandry wastewater generated from confined animal operations.