Transient nature of riverbank filtered drinking water supply systems - A new challenge of natural radioactivity assessment

• Published in: Journal of environmental radioactivity Vol. 211; p. 106072
• Main Authors: Csondor, Katalin, Baják, Petra, Surbeck, Heinz, Izsák, Bálint, Horváth, Ákos, Vargha, Márta, Erőss, Anita
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01-01-2020
• Subjects: Drinking Water; Flow system; Groundwater; Hungary; Natural radioactivity; Radiation Monitoring; Radioactivity; River bank filtration; Uranium; Water Pollutants, Radioactive; Water Supply; Hungary; River bank filtration; Drinking water; Flow system; Uranium; Groundwater; Natural radioactivity
• ISSN: 0265-931X; 1879-1700
• DOI: 10.1016/j.jenvrad.2019.106072

In Hungary the drinking water supply is mainly based on groundwater, in which radionuclides are common components. Since the mobility of the most common radionuclides, uranium and radium, is strongly influenced by the geochemical conditions, knowledge on the geochemical parameters of water is required. This depends on the flow system and the flow regime. Therefore, hydrogeology has a crucial role in revealing the origin of elevated activity concentrations. This research presents a case study in Hungary where the drinking water supply is provided by bank filtered and karst wells. In most of the wells of the research area the gross alpha values are above the screening level, 0.1 Bq L−1. The aim of this study is to determine which radionuclides may cause the elevated radioactivity and explain their occurrence using the hydrogeological approach. All samples of the study were analysed for (U-238+U-234), Ra-226, Rn-222. Alpha spectrometry applied on Nucfilm discs was used to measure the uranium and radium activity while radon activity was determined by liquid scintillation. The study revealed the correlation between the river water level fluctuation and the uranium content of the wells. The results of this study highlighted the transient nature of river bank filtered systems, which should be taken into account in the monitoring and water supply strategy.
•Riverbank filtered wells' uranium content depends on river water level fluctuation.•High uranium content related to low river water level, as groundwater less diluted.•Radionuclide monitoring must be adjusted to transient riverbank filtration systems.•Nuclide specific measurements are more reliable compared to gross methods.