Who would usually find it completely alright to link fresh drinking water with sewage waste? Not me, at least. But a city in Denmark is bringing the two together, to become the world’s first city to provide fresh water using only the energy from household wastewater.
The water treatment plant in Aarhus is now generating so much excess electricity, the surplus is being used to pump drinking water around the city.
The plant pumps household waste into huge digesters kept at 38°C and filled with bacteria producing biogas that is then burned to make energy in the form of heat and electricity.
Other cities around the world, including Chicago and San Francisco, are now showing interest in replicating Aarhus’ water system.