Abstract
<jats:p>East Kazakhstan has centers for smelting industry and large tributaries to the transboundary Irtysh river. three rivers were taken for research in the neighborhood of Ridder c.: Zhuravlikha, Tikhaya and Filippovka. Comparative characteristic was given to these rivers over 2023-2024, a chemical composition of water studied along the riverbeds, namely: acidity, hardness, concentrations of calcium ions, hydrocarbonate-chloride- and sulfate ions as well as total salinity. The waters of studied rivers are classed as (as classified by О. А. Alekina) with no excess of MPC established by the Kazakhstani legislation and range within the values recommended by the US EPA. The exception is the Filippovka riv., which exhibited hardness exceeding MPC in 2023. Most likely, this was due to a man-made accident that had took place the day before.</jats:p>