Abstract: A process for decontaminating water contaminated by emergent pollutants or micropollutants, includes a step of injecting the contaminated water into a device having a vertically filtering planted organic filter, which planted organic filter includes: an inlet for the contaminated water; an outlet for treated water; filtration and decontamination elements interposed between the inlet and the outlet, characterized in that the filtration and decontamination elements take the form of a planted organic substrate composed of a compost and insoluble aggregates, making it possible for the organic substrate to maintain a permeability of at least 40 litres per hour per m2, preferably at least 70 litres per hour per m2 and particularly preferably at least 100 litres per hour per m2. A device for decontaminating water contaminated by emergent pollutants or micropollutants is also described.