Water having low salt content (less than 500 PPM, Parts Per Million) is termed as freshwater. More than 97% of the water, which is in oceans of course, is 70 times more salty than this desired.
Natural evaporation is the only efficient and sustainable way to remove excessive salts. Evaporation forms the natural water cycle leading to rains and it may also fall somewhere on the land.
For every 1 liter present in the Ocean, less than 8 drops evaporate. Out of this only 1.5 drops fall in the form of rain over the land. This drop after being consumed and discharged into the sea, may not get back to the land in another 3,000 years, which is almost 100 generations of mankind.
So relish even that single glass of water, respect it, dignify it, conserve it, worship it, but don’t treat it with indifference, because you don’t know when you will meet that drop again.