Client: S.I.A.A.P., Paris (Inter-Departmental Sanitation Authority)
Engineering: Campenon Bernard
Process Engineering: OTV - Degremont
Commission: Public Works
Overall Building Area: 130.000 sq.m
Construction Cost: Ffr. 892m
Completed - June 1998
(with S'pace Architectes Associes)

Life Support - Waste
The Colombes plant is key modern installation in Paris' attempt to clean up water returning to the Seine. The plant filters and de-toxifies waste water during dry weather conditions (2.8m per second) or heavy rainfall (12 m per second). Its 3.5 hectare site is within a densely inhabited area and height restrictions meant two thirds of the plant machinery had to be located below ground.

Most of the construction was of in-situ concrete with a 29m diaphragm retaining wall.

The articulation of service routes and visitors circulation routes was designed with the water treatment layout to express the plants processes; we show where water comes in from Paris and where it goes through before returning to the Seine.

As with Mery sur Oise the aim was to make the building legible and move away from the ubiquitous tin shed. Inhabited buildings were separated from the main volume by bridges and the accueil area was designed to include the two listed Eiffel buildings on the site