Geneva - Switzerland

600,000 PE
Dry weather flow: 3.2 m³/s
Full flow to treatment: 6 m³/s

Discharge Consent Reductions

BOD₅ > 90%
COD > 75%
Total SS < 15 mg/l
N-NH₄ < 2 - 3 mg/l (depending on water temperature)
Total P < 2 mg/l

Built in 1967, Geneva-Aïre treatment plant was commissioned to meet the wastewater demands of an increase in population.
The plant had to treat mixed effluents from the Geneva conurbation (from homes, industries, small businesses and tourist locations) and also wastewater from neighbouring districts in France.

By 1980 the plant became overloaded, the water of the Rhone was deteriorating.

Many local residents were affected by unpleasant odours and the plant's operating and maintenance difficulties were increasing.

To meet new discharge standards and the additional load from anticipated development of the area up to 2010, the capacity of the new Geneva-Aïre 2 plant has been doubled and will be capable of treating up to 600,000 PE. The treatment works has been equipped with new compact technologies that are both environmentally friendly and compatible with economic constraints.

Effective, coherent and compact techniques

Veolia Water Solutions & Technologies was responsible for the design, procurement, installation and commissioning of the processes associated with the water treatment system.

Constructed on the original site, with limited space available, the new plant accommodates the latest compact and innovative technology including Actiflo™ lamella settling with ballasted floc and Biostyr™, biofilters. The most stringent nitrogen and phosphorus discharge standards are adhered to under all operating conditions. This high quality effluent is then discharged into the River Rhone.