ARTIFICIAL SALINIZATION OF THE AQUIFER IN POLTAVA SEQUENCE DEPOSITS IN THE VILLAGE OF TARASIVKA, KYIV REGION

Abstract

The article considers an unprecedented case of intentional artificial pollution of the operational aquifer of local significance in the village of Tarasivka, located in Kyiv-Sviatoshynskyi district, Kyiv region by discharges of spent brine. The source of drinking groundwater pollution in the deposits of the Novopetrivska deposits of the Poltava Miocene sequence was established based on the results of express methods application and logical-apriori analysis. Based on hydrochemical tests, analysis of the results of water pumping from wells and calculations of salt migration rate, it has been proved that the source of contamination could only be a red caviar packing plant, which, according to the regulatory raw mate-rial washing technology, produces significant volumes of brine effluents. At the beginning of the study, several possible options for increasing water mineralization were considered, but all signs point to only one source. Firstly, the content of calcium, sodium and chlorine ions in the water is excessive, which rejects the possibility of its contamination from the chemical storage site, which is also located in the area of possible impact; 2) the source of pollution is located higher above the groundwater flow, i.e. in the area of its supply; 3) mineralization (due to the pres-ence of NaCl) in the water of the well, located 440 m downstream from the source of pollution, increases with increasing flow rate and duration of pumping and decreases after rains and infiltration of meltwater, which resembles seawater intrusion into coastal intakes, 4) mineralization increases along the aquifer from top to bottom, in accordance with the density and viscosity of the solution; 5) increased mineralization of this groundwater aquifer in this area is not an isolated phenomenon, salt water was found in wells only downstream from the above mentioned enter-prise, in addition, it appeared sequentially, first in a nearby well (365 m) – in about 5 years, then in another well (440 m) – in 6 years, which corresponds to the convective salt transfer rate in sand deposits at the appropriate flow gradients.