Covering an area of 116 km2, the objective of this station is to purify wastewater from a large part of the agglomeration of Liège (10 municipalities) before discharge in the Meuse. While the water is non-potable, it is clean enough to be safely absorbed by the Meuse after processing at the station.
The plant of Liège-Oupeye uses the activated sludge process. This is a purification process known for its efficiency and robustness. It allows for the easy removal of nitrogen and phosphorus using bacteria. The station is also equipped with a secondary treatment to meet European standards more stringently.
The sludge sufficiently mineralized to stop fermenting thereafter but still contain enough organic matter to allow recycling in agriculture to produce energy. Moreover, this process does not produce odours and treatment ponds may remain open without nuisance to residents and operating personnel.
The purification station in numbers: