It has been established that in all sections of the rivers under study, cases of pollution with biogenic substances have been identified, which differ both in their concentrations and in the cases of their detection. In each river section, the intra-annual dynamics of the degree of biogenic pollution was revealed, followed by the determination of the dominant pollutant for each river ecosystem. The most environmentally unfavorable periods of time associated with this pollution have been established. The most unfavorable river section was revealed, which was the Byk, which has the highest degree of pollution and degrading state. It is shown that when assessing the quality of river water from an ecological point of view, inflows according to the same indicators had different quality classes. However, class V was determined in all river ecosystems, which indicates the fact of an increased anthropogenic load, associated primarily with the inflow of both recent and permanent pollution into the rivers.