Refers to liquid waste or sewage discharged into a river or the sea.
El efluido que sale de la fábrica debe ser tratado adecuadamente para evitar la contaminación del río.
The effluent that comes from the factory must be treated properly to avoid contaminating the river.
El efluido de la fábrica estaba contaminando el río cercano.
The effluent from the factory was contaminating the nearby river.