Soil-based constructed wetlands for discharge of treated wastewater are currently seen as a valuable technique to reduce flow to surface receiving water bodies and to perform complementary treatments. In France, more than 500 constructed wetlands for discharge of treated wastewater have been built over the last ten years (Prost-Boucle & Boutin, 2013). Performance and lifetime derive from a dynamic interaction between physical, chemical, and biological processes that is not completely understood. Infiltration of large volumes of treated wastewater in soils could modify soil structure and physico-chemical characteristics, leading to a loss of water renovation capacity. Clogging is one of the critical parameters. If a limited degree of clogging can enhance purification, severe clogging can reduce the hydraulic capacity below the operational loading rate leading to anoxic soil conditions (McKinley & Siegrist, 2011; Siegrist & Boyle, 1987; Van Cuyk et al., 2001). This work will focus on: (I) the description of removal rate of organic compounds, retention of inorganic pollutants, and ammonium transformation in soil; (II) the observation of the influence of wastewater loading rate and intermittent loading on soil clogging on pilot-scale laboratory columns.