the water from you FW tank? I've read where some people don't and i don't understand why not. If you have sanitized your system what is there to be afraid of??
Just a quick story... Back in '77 we filled our tank at the city park campground in Montrose SD. (Funny how we will never forget Montrose.) We made lemonade with that water and we were sick for over a week. You should have seen me drag my butt out to see Mt. Rushmore. Sick as dogs, we were.
That's why we will always bring our own drinking water from home.