Aha,

good ol' Nalgenes

We used a couple of 1L ones when we did our Sierra hikes with Scouts years ago. Of course, there used to be water every 5 miles on those hikes too, so no need to carry gallons. And we drank from creeks, lakes, and springs without fear of "beaver fever" and I cannot recall any cases of a kid or adult getting sick. Maybe we were just tougher?

The desert is a true treasure for him who seeks refuge from men and the evil of men.
In it is contentment
In it is death and all you seek
(Quoted from "The Bleeding of the Stone" Ibrahim Al-Koni)

member of the cabal of dysfunctional squirrels?