Is there any conceptual difference between "Liquid refuse" and "Liquid waste"? What are the differences, if any? Is any of them used more than the other?
It feels to me that "liquid waste" is more used in common language.
If there is no conceptual difference, I'll go with the most commonly used. If there are conceptual differences, though, I'm chosing the one which most closely refers to waste in liquid state as it is discarded in industrial/residential pipes. If my word choices are not the best ones and there is a third even-better one, please enlighten me.
[EDIT: adding contextualization]
Maybe I should provide some contextualization. I'm describing the following scene: it's raining and one person is disgusted because the water that is spilling on his face are not just raindrops, but it is mixed with water/greywater/waste water/liquid waste/whatever disposed from the buildings above him. He does not acknowledge them being industries or residential buildings, but he knows he's not being under pure raindrops. In this context, what better describes this generic dirty water? Greywater? Waste Water? Liquid Waste?