Baikal water is exceptionally pure. It has a very low
degree of mineralization, up to 96.6 mg/1. The Buryat poet, D.Ulzytuev said of Baikal:
"Because in its depths it is pure and peaceful, Baikal is joyful and free". In actual
fact Baikal's water is purest in its depths.
Dr. K.K.Votintsev devoted many years to the study of the chemical composition of
Baikal's water. Over the last ten years during which the threat of pollution has been
growing the problem of working out a quality standard for Baikal's water has posed
itself. As this investigator reports in one of his posthumous articles, in 1975 the sampling of water from the surface to the bottom
all over the lake was undertaken. More than 1000 samples were analysed, and it
was proposed to take the average of various components as the standard quality of
the water. The results were the following in milligrams per litre: carbonates 65.60,
calcium 15.77, sulphates 4.85, sodium and potassium 3.56, magnesium 3.10,
chloride 0.56, nitrates 0.34, phosphorous 0.028, total mineralization (ionic) 93.81.
The water is defined as being of the carbonate-calcium type. Up to 11.44 mg/1 of
oxygen, 2.87 mg/l silica, 2.72 mg/l carbonic acid and organic matter is also present
in the water. Waters below the 200 metre level correspond more closely to this
Baikal water, especially in the deepest parts of its great mass, has a
surprisingly constant chemical composition.
River waters, and especially the waters of the Selenga influence the
concentration of individual ions in the water. Some components vary spatially and
seasonally. First and foremost this concerns the biogenic elements - Si, P, N, and
also oxygen, carbonic acid and organic substances.
Silicon and phosphorous in the water are used by diatomic algae, after death
the remains of these settle on the floor of the lake, forming diatomic silt. The
silicon and phosphorous end up in this silt where, for example, as much as
500,000 tons of silicon earth settles yearly. The fate of nitrogen in the cycle of
matter has as yet not been cleared up. Organic matter in water is subject to decay,
and part of this also goes into the floor sediments.
Baikal waters situated at a distance from human settlements and particularly
deep waters are quite pure, as researchers at the Limnological Institute have
shown, in the bacteriological sense, and only near settlements does slight bacterial
pollution of the waters occur including bacteria that are dangerous to human
The low level of mineralization of Baikal's water is due to the low
mineralization of the waters of its tributaries. The Selenga, the lake's main
tributary, brings water with an average mineralization of 126.81 mg/l, the
Verkhnaya Angara - 81.31, and Barguzin - 134.47. Most mineralized are the
waters of the river Buguldeika which reaches 300 mg/1.
The low mineralization of the water of the tributaries can be accounted for by
the fact that the Baikal basin is composed mostly of metamorphic and magmatic
rock not containing easily dissolved minerals. The river Buguldeika washes away
carbonate and, possibly, salt-bearing rocks.
Like the waters of the lake itself, the waters of the tributaries are neutral or
slightly alkaline in their degree of acidity (pH 7.0 - 8.2).
The microelement content of Baikal water has not been sufficiently studied,
but it is known that, for example, the heavy metal content is extremely low.