Hydrochemical Characteristics and Water Quality Assessment of Irkutsk Reservoir (Baikal Region, Russia)

The Irkutsk Reservoir, belonging to the largest unified freshwater Baikal–Angara system, is an important source of drinking water in the region. Therefore, studies of its hydrochemical characteristics are of prime importance in deciding on the role of anthropogenic activity in water quality. The water samples were collected across the reservoir in 2007, 2012, and 2021 and then were analyzed for major ions and trace elements. The data revealed that the distribution of HCO3−, SO42−, Cl−, Ca2+, Mg2+, Na+ and K+ is stable across the reservoir. Trace element concentrations varied from 1.13 to 15.39 µg L−1 for Al, from