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

  • MCHF d’investissement pour la nouvelle extension

  • habitant∙es raccordé∙es à la STEP à l’issue des travaux

  • litres d’eaux usées traitées chaque seconde

  • décision du projet d’utilité publique par le Conseil d’Etat

Visite virtuelle

En attendant de pouvoir visiter cette installation novatrice, nous vous proposons une visite virtuelle.
Les collaborateurs et collaboratrices SIG vous guideront depuis les toitures de l’ouvrage jusqu’au cœur du traitement biologique ! Cet ouvrage industriel incontournable du canton n'aura bientôt plus de secrets pour vous.

Commencer la visite

Where to find us