Work

Assessment of the current ecological state of the Tolych River basin under intensive technogenic load

Year: 2026

Type: article

Abstract: Relevance. The need to investigate rivers with complex water management situations, as they are characterized by unsatisfactory ecological conditions and significant alteration of natural hydrological and hydrochemical characteristics. Aim. To assess the current ecological state of the Tolych River (Perm Krai) resulting from long-term wastewater discharge impacts. Objects. Environmental components – water and bottom sediments of the Tolych River. Methods. For all wastewater outfall points, in accordance with SP 529.1325800.2023, calculations of the intra-annual runoff distribution for the unstudied river were performed for a low-water year (P=75%) and a very low-water year (P=95%), which model possible conditions of maximum technogenic impact. The macrocomponent composition of the waters was determined in accredited laboratories using certified methodologies. Results. The paper introduces the results of an assessment of runoff formation and water quality in the Tolych River within the city of Berezniki. Half of its catchment area is designated for industrial use, hosting chemical and energy sector productions, non-ferrous metallurgy, and their infrastructure facilities (settling ponds, sludge reservoirs, technological roads and railways, pipelines). It was established that the volume of wastewater entering the river basin exceeds by many times the critical values at which it could maintain natural hydrological, hydrochemical, and ecological conditions. A joint analysis of data on the average monthly volume of wastewater discharge and the monthly runoff volume led to the conclusion of a critical situation regarding the ratio of technogenic to natural runoff in the lower reaches of the Tolych River (below outfall 569). In general, active dilution processes occur in the Tolych River after outfall 569 – mineralization decreases by 2.5 times, flow velocity increases by 3 times, and a decrease in the sum of salts in the aqueous extract of bottom sediments – was noted (by 2.8 times). The highest exceedances of the fishery Maximum Permissible Concentration in river water were recorded for chloride ions and sodium and calcium ions (3.9, 1.3, and 2.4 times, respectively). Among nutrients, an exceedance was identified only for nitrite ions, with the highest value noted at point T5 (up to 30 Maximum Permissible Concentration). The outcome of the work is the conclusion about the necessity for territorial monitoring of small tributary rivers of the Kama Reservoir that receive wastewater. For citation: Ushakova E.S., Menshikova E.A., Larchenko O.V., Pigilev R.A. Assessment of the current ecological state of the Tolych River basin under intensive technogenic load. Bulletin of the Tomsk Polytechnic University. Geo Assets Engineering, 2026, vol. 337, no. 9, pp. 90–102. http://doi.org/10.18799/24131830/2026/9/5302

Source: Bulletin of the Tomsk Polytechnic University Geo Assets Engineering

DOI: 10.18799/24131830/2026/9/5302

Authors: Evgeniya S. Ushakova, Elena A. Menshikova, Olga V. Larchenko, Roman A. Pigilev

Institutions: Perm National Research Polytechnic University, Tomsk Polytechnic University

Language: English

Topic: Water Quality and Pollution Assessment

Subfield: Water Science and Technology

Field: Environmental Science

Domain: Physical Sciences

SDG: Clean water and sanitation

Open Access status: diamond

Funder: Ministry of Science and Higher Education of the Russian Federation