Waste-water drain
 

What is the proper amount of drop per foot for a sewer line/waste water drain?

Standard is 1/4" per foot for pipe sizes under 6". Over 6" it drops to 1/8" per foot.

That's exactly how much I was thinking it was, but I wasn't sure. Thank you very much.

That is a minimum pitch, the maximum is vertical.
If someone says something about water outrunning solids it is a busted myth.

Job done. and water does indeed go down hill!:beer: