The Danish water supply is based on 100 % groundwater and it is highly decentralized. 

Approximately 120 drinking water- and sewerage-utilities are organised as companies which primarily is owned by the municipalities. They are responsible for water supply, sewerage collection and treatment, storm water management and partly climate change adaptation.

While these, public owned, drinking water utilities supply the more densely populated areas approximately 2000 private cooperatives supply mostly villages.

Water treatment plants which is connected to public networks are without exemption owned by the local authorities and operated by the municipality owned companies.