I wonder if 100% purification is even desirable?
There's plenty of baddies in the water I drink (straight from the tap, or even the hose), but I don't get sick because I'm immune to them.
Travel around enough, and you encounter new bacteria and virii and all that stuff... So it's important to filter/clean you're water. But, if you're always drinking 100% 'dead' water, you will never develop any immunities to the bad stuff.
Then one day, when you're forced to drink from a tap, maybe even in you're own country... it kills you.
Any relatively healthy person will be "safe" with a standard chemical treatment and a halfway decent filter. It's OK to get a little bad with the mostly good... We're talking 1 percent of a microscopic amount here! IF THAT.
Ever eat at restaurant? Use a public restroom? live on a boat!!? There's plenty of bacteria and virus's around us all the time, most of them are not harmful... Same is true with water. If you can eat in a restaurant in any given destination
, you can drink the water. Now, if you filter it, and maybe even put a little bleach in it, you have NOTHING to worry about