Switzerland must take care of its groundwater

Water is the basis of all life on our planet – and water is also essential for social and economic progress. However, the value of “blue gold” is still underestimated, at least in water-rich industrialized countries, and the use of water is unsustainable. The United Nations has been warning for years about a global water crisis that is being aggravated by climate change. In the Global Risks Report 2022 of the World Economic Forum, short- and long-term environmental risks occupy the top ranks ahead of social, geopolitical and economic risks.

Switzerland is only marginally affected by the global water problem in any direct way: We are Europe’s water castle and are barely familiar with water scarcity or quality problems. And even during hot years, there is so much water that agricultural areas can also be supplied with sufficient water. High rainfall in the Alps feeds rivers, lakes and groundwater reservoirs, while snow and glaciers serve as water reserves. But for how much longer? A detailed look at the water situation in Switzerland shows that a rethink on the country’s approach to water resources must also take place here.

Fresh water, salt water, drinking water, groundwater, surface water, wastewater, and so on – there are many different types of water. Whenever it comes up in discussion, one usually equates the term ‘water’ with drinking water. Of the drinking water consumed today in Switzerland, 55 % is attributed to households and small businesses, and 25 % to trade and industry. 5 % is used for public purposes, such as fountains, and around 3 % for the internal consumption of water utilities. Water losses in the distribution system amounts to as much as 12 %, according to the Swiss Gas and Water Industry Association (SVGW). Overall, drinking water consumption has declined from 500 liters per capita and day in 1977 to 410 liters per capita and day in 2000, and to 300 liters per capita and day in 2020.

This development – driven by a growing awareness among consumers, water-saving household appliances and more efficient water use in industry and trade – is pleasing. However, it only shows consumption developments within Switzerland.

Drinking water is most important to people. In Switzerland, 80 % of it comes from groundwater, of which about half is spring water, while 20 % originates from lakes and rivers. Groundwater is therefore an extremely important domestic resource and at the same time a key element of the natural water cycle. Groundwater occurs when rainfall or surface water – e.g. from streams and rivers – seeps into the soil. It flows into underground cavities and comes back to the surface as springs or through pumps. Groundwater quality partly depends on the quality of the soil, which can restrain or filter out pollutants.

While Switzerland has very large groundwater reserves, the groundwater is becoming more and more polluted. Increasing temperatures and contaminants reduce the water quality. Pesticides, nitrate from fertilizers, solvents and cleaning agents from industry, as well as detergents, shower gels and medicines from households – groundwater pollution has no limits. Micropollutants (organic trace substances) are particularly serious. They can get into groundwater in the form of heavy metals, microplastics or other synthetic substances. Almost all protagonists in the economic system – ranging from the petrochemical and agricultural sectors, retailers and construction companies through to hospitals and households – are responsible for such pollutants.

These sometimes highly toxic substances flow with wastewater into treatment plants. While natural pollutants can be broken down relatively easily by the microorganisms used in the clarifying tanks, synthetic substances are largely unchanged as they make their way back into the rivers and lakes. Furthermore, groundwater regenerates only very slowly; contaminants can still be found in it today even though their use was banned many years ago.

The NAQUA National Groundwater Monitoring service – the joint monitoring program of the federal government and cantons – records the quality and quantity of groundwater at around 600 monitoring stations in Switzerland. A 2019 study showed that nitrate and residues from pesticides impair groundwater quality the most. Especially affected are groundwater reserves in the midlands, which practice intensive farming and are densely populated (see Chart 2).

Society, government and the business community have recognized the need for action and are pulling together to protect groundwater. The federal government plans to preserve groundwater resources as well as habitats dependent on groundwater, such as swamps, spring biotopes and wetlands. For this purpose, it has developed an integrated strategy for water protection, which is to be implemented by the cantons. In line with the revision of the water protection law, the Parliament in 2014 laid the foundations to finance the upgrades of selected treatment plants. The new regulations have been in force since 2016, and their main objectives are to safeguard the quality of drinking water, to protect flora and fauna, and to reduce the amount of pollutants that drain into countries that are located downstream.

What does this mean in concrete terms? By 2040, around 100 of the 800 treatment plants in Switzerland should be equipped with additional treatment stages for the removal of micropollutants. As a result, many organic trace substances could be eliminated from wastewater in regions with heavily polluted waterways. Among the treatment plants affected by these measures are the biggest wastewater treatment plants (known as ARA) in Switzerland, large treatment plants in the catchment area of lakes, as well as smaller treatment plants that pipe wastewater into rivers even though it still contains more than 10 % organic trace substances. Starting in 2028, small plants that channel their wastewater into waterways located in environmentally sensitive areas will be included.

The project is financed by a special-purpose wastewater fund of the federal government, which is contributing 75 % to the upgrade of the treatment plants. The fund is supported by a wastewater tax that is charged throughout Switzerland and is intended to bring in around CHF 1,25 billion by 2040. A decisive factor for the tax levied by the federal government is the number of residents who are connected to a treatment plant. As soon as the proprietors of the treatment plants have implemented the relevant measures for the elimination of trace substances, they are exempt from the tax.