In Baikal, instead of water, a solution of chlorhexidine is poured? Then you can’t drink it at all, even with boiling.

Where are your eyes, hell! The shuttler got angry, turning George and pointing to the river. It’s not too much, I could see".
" and George cried out, starting to think. But we can’t drink the river!
"Maybe, but you can drink in the throat well, followed the answer. I’ve been drinking it for 15 years.
George objected to the guard that his appearance could not serve as a promotion of river water and that he, George, preferred well.
We got some water in the cottage, located a little higher. I think that if we were to start investigating, it would prove that this water was taken directly from the river. But we didn’t try and everything was fine. What the eye does not see, the stomach does not feel.