The water is deliciously tasty and pure as a spring. And this notwithstanding the problems posed by the cellulose industry. Baikal has powerful defensive mechanisms of self-purification.
The total mineralization of the Baikal waters is 120 mg/l. The waters of Baikal belong to poorly mineralized soft waters. On average the share of hydrocarbonate calcium is about 84 %, chlorides and sulphates - 7 %, alkaline metalls - 9 %. The chemical composition of water is comparatively homogeneous due to intensive mixing up.
The main tributaries carry 6013 thous. tons of salts and 7809 thous. tons of dissolved compounds. Besides, 1200 thous. tons of different compounds come into Baikal from the atmosphere.
Baikal as a waterbody is filled up with surface waters. Rivers have no time to be saturated with salts, since crystalline rocks in their beds are difficult to dissolve, hence, they carry the water of poor mineralization into Baikal. The water has very high drinking qualities.
May be it is possible by the chemical sets of elements, but as for its molecular structure and isotope composition it seems unlikely.
On average the water exchange occurs during 383 years.
Indirect studies and isotope analyses determine the maximum age of the Baikal water approximately as 400 years old.
The Baikal water contains small amounts of dissolved and suspended substances, that is why, its transparency exceeds all lacustrine waterbodies in the world and is almost equal to transparency of ocean waters.
Taking into account modern optimal need in water, equal to 500 l of water per individual a day, people of the Earth could live on the Baikal water for about 40 years.
In regions with greatest depths in the southern and middle troughs. Secchi disk measurements have shown 40 m on the surface (standard - the Sargasso sea: 65 m.). Studies at the depth from 250 m determined transparency not less than in the Sargasso sea.
On space photoes the bottom relief is seen to the depth of 500 m. Absolute measurements record the disappearance of day light at the depth of 1500 m. Photosynthesis occurs to the depth of 70 m.
In the water thickness microbiological destructive processes became more active. For instance, the number of bacteria, growing on fish-peptone agar, increased by several ten times, there appeared many putrefactive bacteria. By the number of these bacteria the zone of waste water impact is more dictinctly defined. In the impact zone in some periods all 100% of specimens of the endemic planktonic species - Epishura - are dead. In this zone there are many unusual for Baikal species, coming into the lake from treatment facilities. The belt of polluted waters is regularly and constantly recorded at a distance of 7-10 km from the shore. Currents along the coast carry polluted waters far in the direction of the northern part of Baikal.
Autonomous diving apparatuses "Pisces" were first brought to Baikal by the Institute of Oceanology of the Academy of Sciences in 1977.
The main task was geological and biological studies of the Baikal depths.
When the apparatuses were based on the Baikalian Biological station of the Scientific-Research Institute of Biology of Irkutsk State University, scientists of this institute participated in the work of "Pisces". One of the participants of diving prof. O. M. Kozhova in her account shares her impressions: "I was much surprised that all I knew about Baikal from books, my own experience, analysis of hydrobiological sampling appeared to me as a film. Sinking to the bottom we passed three vertical zones. The upper zone is autotrophic dominated by algae, and we saw through port-holes dazzling green water. Deeper than 50-70 m the water colour changed sharply to grey-whitish . This is a zone with dominant zooplankton, among which you can see big specimens of pelagic Amphipoda - macrohectopus- and fish - Golomyanka. Deeper 150 m the water was crystal clear. It seemed as you were on land. Nearer to the bottom , i.e. at a depth of about 500 m there appeared again alive organisms, but these were species leading a pre-bottom way of life - gammarids and goby. The bottom proper in the main trough of Baikal is filled up with loose suspended material. Small elevations on it are habitats of worms - oligochaetes. Now here, now there is seen soaring like parachutes in the air the fish - golomyanka. Rising up the trough slope of the lake, along narrow stony canyons, we saw how diverse is the morphology and colouring of gammarids. Gammarids are lords of this zone - the batial of Baikal, kingly lords"