Assessment of quality and degree of protection for groundwater in Vladikavkaz city

Abstract

Relevance. The article presents the results of complex research of groundwater used for drinking purposes in the Promyshlenniy area of Vladikavkaz, where there is a danger of their anthropogenic pollution in the process of infiltration of pollutants from the dumps of the enterprise “Electrozinc”, as well as a constant increase in their water withdrawal. The data obtained in the course of the work will give scientifically grounded prerequisites for the development of actual recommendations aimed at preserving the natural quality of groundwater from external pollution. Aim of the work is to obtain information on the quality and degree of protection for groundwater of water intake facilities of Vladikavkaz: Zavodskoy site, site “Severny”, “Daryal” and “Agrofirma Fat”. Methods. Such parameters of hydrochemical composition of groundwater as total mineralization, hardness, hydrogen index, permanganate oxidizability (COD), content of major ions, fluorine, nitrates, manganese, total iron, aluminium, strontium and chromium were investigated. Peculiarities of chemical composition were identified and general assessment of groundwater quality was carried out, and data were obtained to determine the degree of protection of the exploited aquifer from external sources of pollution. Result. Since the 2000 s, there has been an increase in mineralisation, chloride ions and nitrate ions content, groundwater hardness index, which exceeded MAC standards several times, which indicates the technogenic impact on the underground hydrosphere, resulting in partial deterioration of the quality of the withdrawn water. Other investigated components are contained in groundwater in permissible quantities. As the analysis of available hydrochemical data has shown, in spite of increased hardness indicators, groundwater is characterised as conditionally clean (1st quality category), in terms of resistance to anthropogenic impact – steady state. According to the degree of protection, groundwater of the exploited Akchagyl-Apsheron aquifer complex in the Promyshlenniy area of Vladikavkaz can be considered as protected (V category of protection according to V.M. Goldberg).