Having caught Giardia once, I will boil water at least a minute if I can't treat it or filter it before I drink it.

I don't recall their names, but I think there were a couple other nasties out there that required a rolling boil for a bit longer.

In most cases, if I have a source of heating the water, I can get it to a boil and keep it there long enough.

Y'all do what you think is best for you. I've learnt my lesson.

Watching Les, he always gets his raw water boiling for a while. That together with my own experiences is gospel to me.