ASSESSMENT OF THE SURFACE WATER QUALITY OF THE TRANSBOUNDARY RIVER WESTERN BUG BY THE CONTENT OF NITROGEN COMPOUNDS

Abstract

In the article, we considered the importance of monitoring and improving the water quality of the transboundary Western Bug River. It belongs to the Baltic Sea basin and covers the territory of three states (Ukraine, the Republic of Poland and the Republic of Belarus). The largest sources of water pollution of the Western Bug River are identified and listed. These are housing and communal enterprises, livestock complexes, landfill leachates of the city of Lviv, spontaneous landfills, and others. The state of water quality of the Western Bug River was analyzed by the content of nitrogen compounds at three observation points (704 km is Kamianka Buzka town; 637 km is Sokal town; 569 km is Ustilug town, 500 m below the confluence of the Ustilug River near the border with the Republic Poland). Research revealed exceeding the maximum permissible concentrations of ammonium and nitrite. The highest exceedances of permissible values of ammonium and nitrite content were recorded at observation point 704 km, Kamianka Buzka town (1.1–30.1 times and 1.1–28.8 times). The content of nitrates varies during the analyzed period from 1.20 mg/dm3 to 18.00 mg/dm3 (704 km, Kamianka Buzka town), from 1.70 mg/dm3 to 21.00 mg/dm3 (Sokal town), from 1.50 mg/dm3 to 20.00 mg/dm3 (Ustilug town, border with the Republic of Poland) and it is within the permissible values. The worst water quality in terms of the content of nitrogen compounds is in the area of the river Western Bug 704 km, Kamyanka Buzka town. In particular, water quality varies according to the content of NH4+ – from class IV, category 6 (polluted), to class V, category 7 (very polluted); NO3¯ – from class III, category 5 (moderately polluted), to class IV, category 6 (polluted); NO2¯ corresponds to class V, category 7 (highly polluted). The authors of the article recommend to improve the water quality of the river Western Bug to ensure the construction, reconstruction and modernization of treatment facilities, sewage networks of settlements, to more carefully control the inflow of pollutants from the landfill of Lviv city and spontaneous landfills.