Risk analysis for groundwater intake in an old mining shaft with increased chloride content, Upper Silesia, Southern Poland

Water from underground intakes is the main source of potable water for people in Poland, hence the protection of its resources is of great importance for the functioning of society and the economy. A new regulation in Polish Water Law imposes the obligation of performing risk analysis for water intakes, including the assessment of health hazards, factors negatively affecting water quality which are identified on the basis of hydrogeological and geological analyses. The main objective of the study was to determine the health risk for chlorides and to present an innovative approach to the health risk for non-toxic substances. In Upper Silesia, which is the most industrialized and urbanized area in Poland, old mining shafts are often used as deep wells in the water supply chain, and higher mineralization is the key feature of abstracted water which does not quite eliminate them as a source of drinking water supply. This paper proposes a new method of health risk determination as hazard index (HI). We present analysis of the health risks with increased concentration of chlorides in water which cause health effects for water consumers, especially for men, children aged 4–8, pregnant women and women during lactation. HIGHLIGHTS Children and the elderly are the most threatened by consuming chloride-rich water.; Mining water causes an increase in the chloride concentration of drinking water.; The extended health risk assessment should be done for the water intake localized on mining or industrial area.