Clive I grew up in a place where city water was and is fully drinkable out of the tap. Delicious. For some reason water obtained at 7,000 feet is just naturally more pure.
Now we filter water down here on the coastal Sonoran desert. And it is still awful. If my roses are getting aphids I just hose them off with tap water and it kills them.
My point being that it is very difficult to get pure H2O. And when you find it it cannot be in a plastic bottle because stuff comes off the biodegradable bottle.
Now if you can stay above say 4.500 feet near a rim area of say 1,000 feet and have a spring. They water filters though layers of rock or formations. That water comes out perfectly safe to drink but has a lot of sediment or dirt in it.The sediment is minerals, including healthy salts. Normally it tastes delicious, much more so than pure H2O which is tasteless The formations would have taken billions of years to create.
That is the dirty water that man is made from.
Now you mess that up with over fertilizing, pesticides and crap like flouride and chlorine you get the water that unmakes man.
"Water is life" Water made life.
To "dig" a little deeper those formations that make our water perfect for life were laid down by millions of seas, rising and falling and melting glaciers as far down as the Grand Canyon caused by climate change.
And you see that the water capable of making and sustaining life was made perfect by global warming and cooling.
Maybe we need a big change to make our water life giving again.