Discharge of Pollutants with Wastewater in the European Part of the Country and Its Consequences for Water Resources Quality

Abstract

The purpose of the research is to conduct an integrated analysis of the composition and volume of pollutants discharged into water bodies with wastewater in the federal districts and several major river basins (Neva, Northern Dvina, Volga, Oka, Kama, Don, Kuban) of the European part of Russia (EPR) during 2015-2020, as well as to compare pollutant discharges with their actual concentrations in river waters. Materials and methods. The analysis is based on offi cial data on annual pollutant discharges by regions and federal districts within the EPR, as well as on information regarding their average annual concentrations in river waters, obtained from statistical reference books. The study examines concentrations of total BOD (as an indicator of organic substances), petrochemicals, dry residue (mineralization), iron, nitrate-ion, and copper. A method of geographical and hydrological comparison is applied. Results and discussion. It is shown that federal districts diff er signifi cantly from each other both in the amount of total discharge of individual pollutants discharged with wastewater and per capita, km2 of area and km3 of local river runoff . No general, clearly expressed trend in the amount of pollutants discharged in 2015-2020 was revealed. At the same time, exceedances of MACs were observed in most closing sections of the considered river basins and a signifi cant excess of the actual annual removal of pollutants, including the excess, compared to the annual discharge with wastewater. Conclusion. The signifi cant excess of the actual annual removal of pollutants in the closing sections of river basins over the volumes discharged with wastewater indicates the predominant contribution of other sources of pollution, primar ily diff use runoff from catchment areas.