МОНІТОРИНГ ТЕХНОГЕННОГО ЗАБРУДНЕННЯ ПІДЗЕМНИХ І ПОВЕРХНЕВИХ ВОД У ЗОНІ ВПЛИВУ УРАНОВИХ ХВОСТОСХОВИЩ ПРИДНІПРОВСЬКОГО ХІМІЧНОГО ЗАВОДУ (м. КАМ’ЯНСЬКЕ)

The article presents an analysis of data that were obtained in 2012–2013 in the framework of the Swedish-Ukrainian technical assistance project «ENSHURE — Academic», which included comprehensive monitoring studies of the impact of uranium tailings of the former production association «Pridneprovsky Chemical Plant» (PCHP) (Kamyanske) on radioactive and chemical contamination of groundwater and surface water. It was established that migration of contaminants from the «Dneprovskoye», «Zapadnoye» and «Central Yar» tailings causes pollution of the aquifer in Quaternary alluvial sandy deposits in the zone of influence of tailings by uranium-234, 238, major ions (sulfate, calcium, magnesium, etc.), and toxic metals (in particular, by manganese, lead, nickel) in levels, which significantly exceed respective maximum permissible concentrations for drinking water. Discharge of contaminated groundwater to Konoplyanka River, a tributary of the Dnieper, caused the increase of the total dissolved solids in river water (especially of the sulfate ion concentration), as well as uranium-234, 238. The geochemical modeling suggests that uranium-234, 238 migrates from tailings in the form of mobile carbonate and sulfate complexes, which is promoted by predominantly oxidizing hydrochemical conditions in the aquifer. The transport of manganese and lead to surface waters was likely limited by the redox barrier in «groundwater — surface water» system. It was also established that the flooded storm sewers at the territory of the PCHP industrial site acted as drains, and served pathways of facilitated transport of pollutants from the contaminant sources at the PCHP site (such as «Zapadnoe» tailings) to the Konoplyanka river. The presented studies show that along with the radioactive contamination, the chemical pollution of the hydrosphere by toxic elements and major ions is also of serious concern. Hydro-chemical monitoring of the PCHP industrial site has to be continued, the monitoring well network has to to be developed and the list of investigated chemical toxicants needs to be extended.