The wastewater currently generated by the Brussels Region (and part of the peripheral municipalities) and reaching the stations represents around 148 million m3 per year. Three quarters are processed at the North station, the last quarter at the South station. The purification performance of the North Station has been good and stable over the past 4 years. Those of the South Station, on the other hand, are insufficient, especially with regard to suspended matter and nutrients. In order to remedy this, a huge overhaul of the facilities started in 2014. It is however wrong to consider that all wastewater is treated by the stations: recent measures indeed underline the major role of spillways in the transfer of water pollutants to the Senne and the Canal.