Assessing the effectiveness of a constructed wetland for water quality mitigation in Brittany (France) - A case study within the Aquisafe project.


The Aquisafe project assesses the effectiveness of natural mitigation zones in reducing diffuse pollution to surface waters. In one case study on a constructed wetland in agriculturally dominated Western France, nitrate concentrations from drainage inflows to a small river decreased up to tenfold on the way through an intermediary constructed wetland. However, only ~30 % of the total N-load is retained in the wetland, whereas ~70 % enters the river directly during high flow events as a result of low soil permeability. The study underlines the importance of flow paths and infiltration for nitrate removal in natural or constructed wetlands, which is often neglected in practice.

p 4 In: IWA DIPCON 2008: 12th International Conference on Integrated Diffuse Pollution Management. Khon Kaen, Thailand. 25. - 29.8.2008
Matzinger, A.
Matzinger, A.