Drinking Water

Maintaining the quality of drinking water

Water is our most important nutrient. Water supply of adequate quantity and quality is a human right. Through its research, Eawag is working to ensure that this right can be guaranteed both in Switzerland and in less privileged regions - a major challenge in view of population growth, climate change and pollutant inputs.

A crack in the water tower

In Switzerland, households consume almost 150 litres of drinking water per person per day. 80 per cent of this is obtained from groundwater, the rest from lake water. While lake water usually has to be treated in several stages, most groundwater can be used as drinking water without treatment or with simple treatment. But the supply of drinking water of sufficient quality and quantity can no longer be taken for granted, even in Switzerland’s water tower.

Identifying and reducing pollutant inputs

In intensively farmed regions, nitrate and pesticide residues enter water bodies and groundwater. This poses great challenges for the drinking water suppliers. With its research, Eawag is helping to reveal the extent of the pollution and to develop proposals for improving the situation.

To promote exchange between research, practice and public authorities on these topics, Eawag operates the Platform for Water Quality together with the Association of Swiss Water Protection Experts (VSA) and the Federal Office for the Environment (FOEN), and has also launched the Swiss Groundwater Network CH-GNet.

Optimising water treatment

In addition to reducing pollutant inputs to water bodies, Eawag is also conducting research into water treatment so the pollutants can be removed as efficiently as possible. This involves optimising existing and researching new treatment technologies, but also potential new pollutants such as nanoplastics.

Even if drinking water of impeccable quality reaches consumers, the building installations on the other hand, harbour new dangers. If the water is heated, legionella can form - bacteria that can cause severe pneumonia, known as Legionnaire's disease. A multidisciplinary research team led by Eawag is investigating how this danger can be contained in the “LeCo” project.

Reusing water

With hot and dry summers becoming more frequent due to climate change, supply bottlenecks are also becoming an issue in the water tower of Switzerland. Eawag is therefore researching the reuse of greywater - effluent from showers, washing machines or dishwashers - which can be treated and used to flush toilets or for irrigation. Because it is not necessary to use drinking water everywhere, as we do today.

Research projects

Cyano-metabolites from source to tap
This project facilitates the exchange of data, maps and information on geogenic contaminants (focussing on arsenic and fluoride) via the web-based Groundwater Assessment Platform (GAP)
Inhalation of legionella bacteria – which thrive in warm water – can cause illness: in a new project, an Eawag-led multidisciplinary research team is investigating how the risks associated with these bacteria can best be managed.
WABES explores opportunities for integrated planning, implementation and sustainability of water, solid waste and fecal sludge service provision in urban settings.
NEST building
Sustainable urban water and wastewater management applied and implemented in the modular NEST building.
An inter- and transdisciplinary strategic research program that strives to develop novel non-gridconnected water and sani- tation systems that can function as comparable alternatives to network-based systems.


We work together with a wide variety of partners.

The FOEN Water Division is responsible for the protection of surface water, groundwater and drinking water.

Federal Office for the Environment (FOEN)

The SVGW is the national professional organisation of Swiss gas, district heating and water supply companies.

The Swiss Gas and Water Industry Association (SVGW)


Dr. Christian Binz
  • decentralized systems
  • innovation
  • global change
  • sustainable transitions
  • urban water management
Dr. Frederik Hammes
  • biofilms
  • Flow cytometry
  • Legionella
  • Microbiology
  • sensors
Prof. Dr. Juliane Hollender
  • Computational methods
  • biological degradation
  • bioaccumulation
  • groundwater
  • mass spectrometry
Dr. Stephan Hug
  • arsenic
  • solid-water interfaces
  • groundwater
  • spectroscopic methods
Dr. Tim Julian
  • microbes
  • urban sanitation
Prof. Dr. Rolf Kipfer
  • noble gases
  • isotopes
Prof. Dr. Mario Schirmer
  • groundwater
  • hydrogeology
  • modeling
  • surface water
Dr. Andreas Voegelin
  • wastewater
  • arsenic
  • solid-water interfaces
  • geogenic contaminants
  • nanoparticles
  • spectroscopic methods
  • water treatment
Prof. Dr. Urs Von Gunten
  • advanced oxidation processes
  • ozonation
  • drinking water
  • water treatment
Prof. Dr. Lenny Winkel
  • inorganic contaminants
  • arsenic
  • groundwater
  • organic pollutants
  • sediments
  • selenium

Scientific publications

Guo, Y.; Yu, G.; von Gunten, U.; Wang, Y. (2023) Evaluation of the role of superoxide radical as chain carrier for the formation of hydroxyl radical during ozonation, Water Research, 242, 120158 (10 pp.), doi:10.1016/j.watres.2023.120158, Institutional Repository
Remke, S. C.; Houska, J.; von Gunten, U.; Canonica, S. (2023) Impact of chlorination and ozonation of dissolved organic matter on its photo-induced production of long-lived photooxidants and excited triplet states, Water Research, 239, 119921 (9 pp.), doi:10.1016/j.watres.2023.119921, Institutional Repository
Zhang, T.; von Gunten, U. (2023) Chlorination of amides: kinetics and mechanisms of formation of N-chloramides and their reactions with phenolic compounds, Water Research, 242, 120131 (9 pp.), doi:10.1016/j.watres.2023.120131, Institutional Repository

Cover picture: Zurich water supply filter well in Hardhof. (Photo: Eawag, Urs von Gunten)