An outstanding feat of modern technology: the Mery-sur-Oise nanofiltration Treatment plant (340,000 m3/d)

Abstract The paper presents the new membrane plant built by the Syndicat des Eaux d'Ile de France(SEDIF) in Mery-sur-Oise. The drinking water plant is able to produce a maximum of 340,000 m 3 /d of water (90 MGD) for the North Paris Region. A facility with membrane for 140,000 m 3 /d (37 MGD) is operated in parallel to the existing conventional plant. The commissioning of the membrane plant took place in 1999 and the first thousand cubic meters of water were provided to the distribution system on September 22, 1999. The paper describes how the 9,120 membrane elements were control-checked before commissioning, and how the integrity of the membrane system has been secured. It emphasises the capability of the pre-treatment to provide good quality water in order to control the fouling of the membranes.