Assessment of surface water pollution in Western Bug River within the cross-border section of Ukraine

Monitoring of surface waters within the transboundary section of the Western Bug River showed, that during 2014–2018, a significant excess of the maximum permissible concentration (MPC) was observed for some substances for fish ponds. As a result of this, the water in the river for these substances was rated as “dirty” in terms of purity and corresponded to water quality class IV, namely: phosphorus was observed to exceed the MPC at the observation point Ambukіv village in 2015 (9.7 times), for manganese – an excess of the MPC at the observation point Ambukіv village in 2018 (9.7 times) and in point Zabuzhzhia village in 2014 (7.9 times), 2015 (8.0 times), 2017 (7.1 times), 2018 (8.3 times); for the total iron – the exceeding of MPC at the observation point Ambukіv village in 2016 (5.95 times) and 2017 (6.13 times); at the observation point Ustilug town in 2016 (5.23 times); in the observation point Zabuzhzhia village in 2016 (9.44 times) and 2017 (5.27 times). The assessment of the surface waters based on the determination of the pollution factor showed that during the study period their quality did not deteriorate but did not meet the norms. In general, surface waters of the river correspond to the second class of quality and are characterized as “poorly polluted” waters by the level of pollution.