Seriously though, often it comes from a reservoir and that is mixed with the cleaned sewage water.
The reasoning I've heard is that they clean the poop water so well that they might as well add it back in.
This is how the birth control pills, fentanyl, etc. end up in the drinking water.
There was a story in our local paper about how the fish, frogs and turtles near the outlet of the poop plant are freakish and hermaphroditic. They are all hormoned up from the same crap in your tap now.
good it is