Mettmann Wastewater Treatment Plant: Serving ~34,000 People in Nordrhein-Westfalen

The Mettmann wastewater treatment plant is located in the city of Mettmann, in the state of Nordrhein-Westfalen, Germany. It serves a population of approximately 34,074, classifying it as a medium-sized agglomeration under European Union regulations. As a German facility, the plant operates under the EU Urban Waste Water Treatment Directive (91/271/EEC), which requires secondary treatment for discharges into freshwater systems from agglomerations of this size. The plant's treatment processes and capacity are designed to meet these standards, ensuring compliance with national and EU water quality objectives. The treated effluent is discharged into local watercourses that eventually drain into the Rhine River basin, a major European watershed. The Rhine supports diverse aquatic life and is an important ecological corridor, making effective wastewater treatment critical for protecting downstream water quality and biodiversity.

The plant discharges into the local drainage network within the Rhine River basin, which flows through Germany and the Netherlands before reaching the North Sea. The Rhine supports diverse aquatic ecosystems, including fish species such as salmon and eel, and is a vital migratory corridor. Effective treatment helps protect these habitats from nutrient pollution and other contaminants.