What does wastewater mean?
Wastewater is water that has been used for domestic, commercial, agricultural, or industrial purposes and has thereby collected waste, pollutants, or contaminants. The term is broader than sewage: sewage usually refers to wastewater from toilets, while wastewater may also include factory effluent, agricultural runoff, and other liquid waste streams. Its composition and effects depend on its source, so some wastewater may require extensive treatment before it can be discharged safely, reused in industry or agriculture, or returned to the environment. The word commonly appears in environmental regulation, public health, infrastructure, and engineering, especially in expressions such as “wastewater treatment” and “wastewater pollution.” Although the subject can evoke unpleasantness or industrial contamination, modern wastewater management also treats water as a recoverable resource. Effective treatment can remove pathogens and harmful chemicals, conserve freshwater supplies, and reduce the environmental impact of human and industrial activity.
nounWater used for domestic, industrial, or commercial purposes that contains dissolved, suspended, or biodegradable waste. Sewage is a type of wastewater, while the broader term also includes many industrial and agricultural waste streams.
- Water that has been used in homes, businesses, farms, or industrial processes and that contains waste materials, pollutants, or contaminants.
"The plant uses advanced filtration to make wastewater safe for reuse."
"Strict limits on wastewater discharge help protect the river and the wildlife that depends on it."
"The engineer analyzed samples of wastewater to determine which treatment process would remove the industrial solvents."
Rare; wastewater is normally used as an uncountable mass noun. The plural may distinguish separate waste streams.
"The study compared the chemical composition of wastewaters discharged by several industrial facilities."
What flows down the drain does not have to disappear: with the right treatment, wastewater can become a reusable resource.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does wastewater come from?
Wastewater is an English compound formed from “waste” and “water.” Both elements have Germanic origins: “waste” descends through Old English from a Germanic root associated with empty, unused, or unoccupied places, while “water” comes from Old English wæter and likewise has Germanic ancestry. The compound is now commonly written as one word, though the two-word form “waste water” is also established.
How wastewater is actually used
Wastewater is primarily a formal technical and environmental term. It is usually treated as an uncountable mass noun, though the plural “wastewaters” is occasionally used for distinct waste streams. The closed compound “wastewater” is standard, although “waste water” remains common.
Easily confused with wastewater
Wastewater is the broader term for used water containing waste, whereas sewage refers specifically to wastewater arising mainly from human toilets and their associated waste streams.