Waste material such as liquid industrial refuse or sewage that is discharged into the environment
Merriam-Webster Online Dictionary
effluent (adjective)flowing out - emanating outgoing an effluent river
something that flows out as
a) an outflowing branch of a main stream or lake
b) waste material (as smoke, liquid industrial refuse, or sewage) discharged into the environment especially when serving as a pollutant
effluent (Wikipedia)
Wastewater discharge
Effluent is an outflowing of water or gas to a natural body of water, from a structure such as a wastewater treatment plant, sewer pipe, or industrial outfall. Effluent, in engineering, is the stream exiting a chemical reactor.