Effluent

Effluent is an outflowing of water or gas from a natural body of water, or from a manmade structure.

Effluent, in engineering, is the stream exiting a chemical reactor.

Effluent is defined by the United States Environmental Protection Agency as "wastewater - treated or untreated - that flows out of a treatment plant, sewer, or industrial outfall. Generally refers to wastes discharged into surface waters". The Compact Oxford English Dictionary defines effluent as "liquid waste or sewage discharged into a river or the sea".