The results of this study show the necessity of an associated treatment prior to the crossflow filtration on mineral membranes to treat surface waters like Seine River water. In general, ultrafiltration membranes (20 nm, 50 nm) have small fluxes, more stabilized than microfiltration membranes (0.1 um, 0.2 um HP). Also, there is no particular influence of the pore diameter and of the type of treatment on the quality of the permeate. The best results are obtained with the combination coagulation plus ozonation on microfiltration membranes. Ozone allows cleaning of microfiltration membranes with a total and rapid efficiency. This reagent presents another advantage; it is easier to use (rejection, manipulation, production) than the usual cleaning agents (NaOH, HNO3). A new development of the mineral membrane technology in the water treatment associated with a new application of ozone is now possible.