The Aïre WWTP

The Aïre wastewater treatment plant (Aïre WWTP) is one of the largest in Switzerland. Its key role is to conserve the quality of the Rhône's water. It thus treats wastewater from the city of Geneva and the 24 communes in the canton, as well as from parts of the cross-border region.


This site is not accessible to visitors.


The Aïre WWTP replaced a former facility that was there from 1967. It was built between 1998 and 2003, with due regard for the three pillars of sustainable development – ecological, economic and social. Every effort has been made to protect riverbank residents from any possible nuisances caused by the plant.

The Aïre WWTP treats all the sludge produced by all the cantonal treatment plants. This centralised treatment produces nearly 8 million m³ of biogas, which is used for the heat-energy needs of the facility. Any surplus is then transferred into the natural gas network.

Key figures

  • + 445'000 residents are connected to the plant

  • 2'000 litres of wastewater enter the station every second

  • + 80% of wastewater from the Geneva region processed at Aïre

  • 1'100 water samples taken annually

  • 30'000 parameters are analysed in the laboratory