Anthropogenic Changes in the Hydrochemical and Sanitary–Microbiological Characteristics of Water Quality in Southern Baikal Tributaries: Listvennichnyi Bay

A sanitary–bacteriological and hydrochemical survey of rivers flowing into Lake Baikal near Listvyanka Settl. was carried out in period from 2014 to 2015. Water quality at the mouths of the rivers of Bol’shaya Cheremshanka, Malaya Cheremshanka, and Kamenushka was found not to meet the standards of the normative and technical documentation introduced in Russia and abroad (in the United States and Europe) in terms of thermotolerant coliform bacteria, thermotolerant E. coli, and enterococci. In terms of hydrochemical characteristics, such as phosphates, water quality at the mouths of the Bol’shaya Cheremshanka, Malaya Cheremshanka, and Kamenushka rivers also failed to meet Russian standards. The coastal water of Lake Baikal at the mouth of the Bol’shaya Cheremshanka in July (at the peak of tourist season) 2015 showed the abundance of the group of thermotolerant coliform bacteria (TCB) more than 10 times in excess of the standard. Therefore, the study suggests the conclusion that the quality of water sampled at river mouths is much poorer than that in river reaches upstream of the settlement. Moreover, in July, when the recreational load increases appreciably, the abundance of the analyzed bacteria in water in river reaches within the settlement and in water samples taken upstream of it (background points) is found to differ radically. Hydrochemical and sanitary–bacteriological analysis of the coastal water of Lake Baikal was carried out at the mouths of the rivers flowing into it and revealed an effect of river water on the quality of coastal Baikal water.