If you don’t live in a pristine area, if you live in a country where you are downstream from someone(s) who are taking pharmaceuticals for which you don’t have need or prescription…..
As one joker friend of my brother said to another friend….”If we didn’t flush, you wouldn’t have drinking water”…
Hate to say it, for the energy use, but buy a distiller, stainless steel guts, preferably, and make it one of your disciplines to always have a gallon distilling.
What remained for me, across several water systems in different states, was a foul yellow-brown liquid, about a teaspoon and a half.
Post your pics online with a hashtag #distillerresidue, and post a link in the comments, please.