What asian body of water contains 20 percent of the planet's surface fresh water?

Explanation:

Studies on Lake Baikal, located south of Russian Siberia, showed that if the entire world population only drank water from this lake, they could live 40 years without any problem of scarcity. This is the oldest lake that is known and considered drinkable thanks to the cleaning carried out by the microorganisms that inhabit it. Its waters are a paradise for fauna and flora and are also used for different medical purposes.