According to the Royal Academy of Language the second meaning in the definition of emissary says: "Conduction or channel that serves to evacuate the wastewater of a population in a treatment plant, in a river or in the sea." However, in Sea Outfalls we define it as: that conduit that connects an underwater section with another terrestrial one, extending the definition also to the intake or inlet pipes.

 

The following table specifies the different types of outfalls according to their use: