Research of changes in the quality of drinking water in the south-western part of Bryukhovychi (Lviv Region, Ukraine)

Abstract

The drinking water supply of Lviv Region requires special water treatment, a large part of which does not meet the standards due to increased mineralization, hardness and pollution by industrial and domestic effluents. A study of changes in the quality of drinking water from wells of private houses from two streets of the southwestern part of the village of Bryukhovychi was conducted. It was established that for the period 2011–2023 in most of the sampling points, the quality of water has significantly deteriorated, in some – the water composition has changed, many indicators of macro components have exceeded the maximum permissible concentration (MPC). According to the hydrogen indicator, the water from the studied wells is neutral and does not exceed the MPC. According to the degree of mineralization, the investigated water samples from wells of private residences belonged to fresh water, with the exception of the household on the street. Ozhinova, 2, where the water was weakly mineralized. Over the course of 12 years, the situation worsened significantly — in two more wells, the mineralization increased and exceeded the MPC, and fresh water became weakly mineralized. The best situation regarding the mineralization indicator is observed in the well of the household on the Lisna, 8a: the water is fresh, the growth of mineralization is insignificant and the MPC is not exceeded. As for water hardness, in all studied samples the water became hard and exceeded the MPC in two wells. The content of macrocomponents, which exceeds or approaches the maximum permissible concentrations, has also changed. The chemical composition of the studied water samples also changed over the course of 12 years, mainly due to the increase in the content of sulfate, chloride, and sodium ions. That is, in all the selected samples there is a tendency to deterioration of the quality of drinking water. Only from the well on the street in Lisna 8a, the macrocomponent composition of the sample almost did not change, and the water quality of this household remained the best. The content of ammonium, nitrates and nitrites in the studied water samples decreased or increased insignificantly, which indicates a slight anthropogenic influence. Proximity to the Soluky mineral water deposit can probably be a factor in the change in the quality of drinking water. Since the water of the Soluky deposit is sulfate-chloride calcium-sodium, and the water from the wells of the Ozhinova 2, 6, and 7 buildings has changed its chemical composition, being enriched with sulfate, chloride, and sodium ions, similar to the composition of the Soluky, it can be assumed that in the sediments of cracked marls of the Upper Cretaceous, groundwater flows occur.