I get my water by gravity from a creek and for free, have a filter in the garage and another one under my counter and that's it...... being doing it for seven years and I never being sick.

Have also a 3,500 and a 550 gallons tanks just in case there is a nuclear or gas attack and the open water becomes no good... have a line going from the big tank to my underground bunker.

When I go for a walk up in the hills I carry my straw water filter.