What amount of water on earth is drinkable?
Although approximately 70% of the earth is covered in water, a very small percentage is drinkable.
97% of earth's water is salt-water. The remaining 3% is fresh water. However, large percentages of the earth's fresh water is locked in glaciers.
Although most is not readily drinkable, in actuality 100% of the water on Earth is drinkable. Water evaporates from oceans and falls as fresh water, and we know how to desalinate water. Ice can melt and that produces drinkable water. Ground water is what we drill for if you have a well.