Just thinking about my current 5th wheel trailer tank.... but we drink from the tank on 3 different truck campers in the '60s and 70s long time before bottled water. Later a TT and then later three 5th wheel trailers and drank from the fresh water tank on them all.
Of course the first thing I did after getting them home was after purchasing them was disinfect the fresh water tank.
WE don't carry drinking water in the campers.
We also use the shower and toilet in all our units.