Well like so many things in life it depends upon the who, what, where and when...
That is to say Spring water is the best if you can get an excellent source, like the the North Ga Mts... But there are people who live long full lives {over 100 years} drinking silt filled glacier water in some parts of the world... Then if there is not any good water available; as when I was at sea we used distilled water... Even some sea water can be used in certain quanities...
Just maybe I will use my back ground and experience to blog on water resourses...
BTW: I worked for years with the USGS water resources as an electronic engineering technician; installing and maintaining Ground Truth Stations; which were 7 x 24 data loggers; that were used to confirm what the satillies scanned!!
There is a lot of interesting info about water that is not reported...
See ya.. Kermit