Natural water from lakes, rivers and groundwater deposits is collected and cleaned for household use. Every day, we use approximately 60 litres of water for washing ourselves, 40 litres of water in the toilet, 35 litres of water in the kitchen and 20 litres of water for washing clothes. This means that we produce over 200 litres worth of wastewater every day. The waste substances contained in wastewater can be harmful to lakes, rivers and oceans. This is why wastewater is cleaned and treated in sewage treatment facilities. These treatment plants receive wastewater from the sewer system. In sewage treatment facilities, the wastewater undergoes mechanical, chemical and biological processes that result in clear, drinkable water.

A sewage treatment facility.