Emerging contaminants challenge Sweden’s drinking water supply
A quarter of Sweden’s drinking water is produced using managed aquifer recharge. But when water from lakes and rivers infiltrates into the ground, persistent chemicals can travel with it. A new study from the University of Gothenburg shows that improved monitoring is needed to meet new requirements for drinking water quality.
Managed aquifer recharge is used to help secure drinking water supplies. The method involves allowing surface water from lakes and rivers, for example, to infiltrate through the ground and replenish groundwater resources.
In Sweden, around 25 per cent of drinking water is produced using this method. However, surface water can contain chemicals that may ultimately reach the groundwater.
“Surface water used in this process often contains man-made chemicals from sources such as plastics, pesticides and pharmaceuticals, as well as substances known as per- and polyfluoroalkyl substances, or PFAS,” says Tabea Mumberg, a doctoral student at the Department of Earth Sciences at the University of Gothenburg.
Contaminants can reach groundwater
PFAS are a large group of highly persistent chemicals used in products such as firefighting foams and water-repellent textiles. When surface water infiltrates through the ground, there is a risk that these substances can be transported into the groundwater.
In a systematic review, Tabea Mumberg examined previous research on how so-called contaminants of emerging concern (CECs) are transported through managed aquifer recharge systems. These are contaminants that are attracting increasing attention because of their potential environmental and health impacts, many of which are not yet regulated.
The review shows, among other things, that more knowledge is needed about how effectively current systems deal with these substances.
“My study highlights the need for regular monitoring programmes that specifically address CECs. This is particularly important for CECs that are not yet regulated,” says Tabea Mumberg.
New requirements for drinking water
The issue is becoming increasingly important as water supplies are affected by factors such as drought and flooding. At the same time, more contaminants are being identified in surface water and requirements for drinking water quality are becoming stricter.
The study also points to a need to develop managed aquifer recharge systems so that chemicals can be retained more effectively before they reach the groundwater.
“By understanding what happens to these contaminants in our water systems, we can minimise CEC concentrations before the costly treatment of drinking water.”
About the study
The study “Managed aquifer recharge as a potential pathway of contaminants of emerging concern into groundwater systems - A systematic review” is published in Chemosphere. http://dx.doi.org/10.1016/j.chemosphere.2024.143030
For more information:
Tabea Mumberg, PhD student, University of Gothenburg, Department of Earth Sciences, tabea.mumberg@gu.se
By: Jenny Meyer Daneback
