An average of some 140 million litres of drinking water flows through more than 1,800 km of the Dusseldorf supply system every day. That is the equivalent of about 700,000 bathtubs each holding 200 litres of water. Approximately one quarter of local water originates underground and an enormous three quarters through seepage from the river Rhine.
Here, the quality of the tap water is extremely high and is controlled by both European directives and national law. Specimens are taken and tested daily.