Artificial groundwater recharge systems need better monitoring of new chemicals
With an increasing number of new identified chemicals in surface water, and upcoming stricter EU guidelines for clean drinking water, better monitoring of persistent organic contaminants and redesign of artificial groundwater recharge systems are needed, a new study suggests.
Managed aquifer recharge (MAR) is a method commonly used to artificially recharge groundwater systems to ensure sufficiently high groundwater quantities for drinking water supplies. It is a well-developed technology increasingly used for water security around the world. The process involves the artificial infiltration of surface water, like lake or river water, into the subsurface to refill groundwater systems.
While recharging groundwater is an efficient way to ensure there is enough water, it may come with risks.
– The surface water used in MAR often contains man-made chemicals from plastics, pesticides, medicines and substances known as per- and polyfluoroalkyl substances (PFAS), says Tabea Mumberg, PhD student at the University of Gothenburg, Department of Earth Sciences. Her research investigates PFAS migration pathways at different managed aquifer recharge plants.
PFAS are a group of more than 16.000 persistent contaminants found in a variety of products, such as fire extinguishing foams and water repellents in textile. When adding surface water back into the subsurface, there is a risk that these chemicals contaminate groundwater systems.
In a recently published literature review, Tabea Mumberg takes a closer look at the transport process of so-called Contaminants of Emerging Concern (CECs) through MAR systems.
– My study highlights the need of using regular monitoring programs that specifically address CECs. This is especially important for the CECs not yet regulated, Tabea Mumberg says.
– 25 per cent of drinking water in Sweden is produced using MAR so this is a common technique. Little is known about how well today’s MAR technology meets up to new challenges posed by CECs.
Due to extreme weather events, such as droughts and floodings, the water industry faces increasing demands to ensure high quality drinking water. Even though water quality is strictly regulated in the EU, water suppliers also must adapt to lower CEC drinking water guidelines from the EU in the future, as well as an increasing number of identified CECs in surface waters.
Another result of the study highlights the need for possible treatment options to improve the retention of chemicals during MAR.
– By understanding the fate of these contaminants in raw water systems we can minimize CEC concentrations prior to costly drinking water treatment.
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 further information about this study, please contact:
Tabea Mumberg, PhD student, University of Gothenburg, Department of Earth Sciences, tabea.mumberg@gu.se
BY: Jenny Meyer Daneback
