ärbild av barn händer, hälla glas rent vatten från kranen i köket
Photo: iStock

Clean drinking water through groundwater - a major challenge in the future


– Providing clean drinking water by using groundwater in Sweden in the future is a major societal challenge that many are not aware of, says Philipp Wanner, new Associate Professor in Geology at the University of Gothenburg.

Almost 40 percent of the world's food production depends on groundwater. It is through groundwater that almost half of the world's population is supplied with drinking water. Also in Sweden, drinking water providers rely heavily on groundwater. 

Forskaren Philipp Wanner working in his lab
By studying contaminants in groundwater, Philipp Wanner's research group is shedding light on how PFAS enter groundwater systems and how this in turn affects drinking water.
Photo: Malin Arnesson

– In Sweden alone, 82 000 contaminated sites have been identified. They can negatively affect the groundwater and our drinking water when groundwater is used for drinking water purposes, says Philipp Wanner, research leader of the Contaminant Hydrogeology Research Group.

One of the major challenges for providing clean drinking water by using groundwater is the widespread detection of per- and polyfluoroalkyl substances (PFAS) in groundwater. PFAS is a term for around 5 000 industrially produced chemicals. PFAS are widely used in many different products such as in firefighting foam, textiles, electronics, cosmetics, and paints, leading to a large emission of PFAS to the environment, including to groundwater.

 A recent study showed that in almost 75 percent of the Swedish groundwater PFAS can be detected.

– The high quality of groundwater is no longer guaranteed, and the issue of water treatment is increasingly necessary in Sweden, says Philipp Wanner.

PFAS levels above new threshold value affects two million Swedes

The problem with PFAS is that they show adverse health effects already at very low concentrations. Consequently, the Swedish National Food Agency will lower the threshold value for PFAS in drinking water in 2026 to four nanogram per liter for the sum of four PFAS compounds.

However, currently two million Swedes - 20 percent of the Swedish population – have PFAS concentrations in their drinking water that exceeds this new threshold value.

– The new threshold value will force the drinking water producers to increasingly treat the drinking water in Sweden from 2026 onwards to comply with the new threshold value..

– I hope our research will help to better identify PFAS sources and to remediate them which in turn will help the drinking water producers to comply with the new threshold values and to reduce the PFAS emission to the groundwater and eventually to our drinking water, says Philipp Wanner.

For further information about the research, please contact

Philipp Wanner, Associate Professor in Geology, University of Gothenburg, Department of Earth Sciences, e-mail:, phone:  0766-18 56 15

Current research projects within the Contaminant Hydrogeology Research Group:

“Artificial groundwater recharge – A shortcut for harmful poly- and perfluoroalkyl substances (PFASs) into groundwater systems and drinking water supplies”
Financed by Formas
More about the project

“Plastic and pesticides in agricultural soils – A hazardous combination for groundwater systems and drinking water supplies worldwide? (2022 - 2025)”
Financed by the Swedish Research Council 
More about the project



Groundwater is the water present beneath Earth's surface in rock and soil pore spaces and in the fractures of rock formations. Groundwater is at a pressure higher than the pressure of the atmosphere. It is created by rain and meltwater flowing down through soil and ground layers to fill cracks in the bedrock. (Wikipedia, Woessner and Poeter, 2020)

Wikipedia, Woessner and Poeter, 2020