If you drink tap water instead of buying it in bottles, you can save a lot of CO2. Many production steps are eliminated if the water ends up straight from the tap in the glass – for example, transport to the supermarket or home. You can also save money by drinking tap water: the drinking water we supply costs around half a cent per liter including wastewater disposal. The cheapest mineral water in plastic bottles costs many times more.

Substances of concern find their way into the groundwater via wastewater

The soil works like a natural filter that holds back many substances. Nevertheless, substances that have got into the environment can also be found in the groundwater. Many substances in daily use enter the sewage treatment plant as wastewater. In addition, there is wastewater from industry and rainwater. In the sewage treatment plant, the water is cleaned of pollutants. However, some trace substances that are not biodegradable cannot be completely removed in the sewage treatment plants.

Trace substances get into water

However, a small proportion of trace substances remains in the treated wastewater and ends up in rivers and other bodies of water via the effluent of the sewage treatment plant. Substances that are not or only with difficulty biodegradable are particularly relevant. One example are pain relievers with the active ingredient diclofenac, which, depending on the application, ends up in the wastewater when washing or via the urine. The stable chemical compound cannot be completely broken down in the sewage treatment plant, which means that it ends up in the water.

Sweeteners cannot be held back

In light drinks, sweeteners such as cyclamate or saccharin are used – they too cannot be completely retained in the sewage treatment plant and thus pollute our surface waters.

Microplastics are problematic

Microplastics in cosmetics are also problematic. Most of the pollutants from the street are drained into the sewer system with the rainwater, which means that the abrasion from tires that sticks to the asphalt can get into the sewer system. Drugs and their metabolites such as 17-alpha-ethinylestradiol are also examined. The parameter is below the limit of quantification.

Quelle geo.de trinkwasser welche stoffe in klaerwerken probleme bereiten