Trust me. One case of beaver fever and there will be no such thing as too cautious. Very common in our neck of the woods actually. I admit, I wasn't in Canada at the time I was struck down but it was a lesson well learned about having someone else prep drinking water. I only drink water I prepare myself nowadays.

It was a steripen that was used BTW. I don't know if it was user error or malfunction. Maybe the water was too cloudy and didn't have time to be fully zapped before being consumed. I don't trust them anymore regardless. Second time was using one of those useless purification "straws"

Unless I see the water boiling like mad or it tastes like strong iodine I don't get a warm fuzzy feeling. Thus the reason for posing the questions. Now I must admit, water being forced thru ceramic comes out really clean looking. I guess if I am posting from the toilet in a few weeks it can be safely assumed I was no good at working an MSR filter either.

I don't know about Calgary, but up here north of Edmonton the water is more like a scum right now.(around the accessible edge anyway) The north sask river smells and tastes like fuel, and you couldn't pay me enough to use the snow runoff in some areas do to all the chip bags and garbage collected in the water.