It is easy to take water for granted. Clean water comes out of a tap, we use the water and then ‘dirty’ water disappears down the drain. The collection and treatment of urban waste water is essential to protecting human health and the environment because the water that leaves our homes, schools and workplaces is contaminated by organic matter and nutrients.

If released into waterways, these contaminants can make rivers uninhabitable for fish and invertebrates or cause plants and algae to grow excessively.

The widespread introduction of effective waste water treatment during the 20th century has greatly improved human health and environmental quality. For most European citizens, waste water is collected, transported and then treated at an urban waste water treatment plant where components that are harmful to the environment and human health are removed, before the water is returned to nature.

More information about how waste water treatment works can be found in our briefing Urban waste water treatment for 21st century challenges. Additionally, maps detailing urban waste water treatment plants, data viewers and a database are available. The report on Industrial waste water treatment — pressures on Europe’s environment analyses data on emissions from industry to water bodies, sewerage systems and urban waste water treatment plants.