Selm Cappenberg Wastewater Treatment Plant, Selm, Germany

Selm Cappenberg is a former wastewater treatment plant located in the Cappenberg district of Selm, in the Unna district of Nordrhein-Westfalen, Germany. The plant served a small community of approximately 1,969 residents and had a designed capacity of 2,150 cubic meters per day. It is now closed, and its treatment functions have likely been transferred to other facilities in the region. The plant provided advanced treatment, which typically includes nutrient removal beyond secondary treatment. Under the EU Urban Waste Water Treatment Directive (91/271/EEC), agglomerations with a population equivalent (PE) between 2,000 and 10,000 are generally required to have secondary treatment, while advanced treatment is mandated for sensitive areas. Although the plant is closed, its advanced treatment level suggests it operated in a sensitive catchment area. The plant's discharge volume was 498.31 m³/day, indicating a utilization rate of about 23% of its designed capacity before closure. The plant is located inland, away from the coast, so treated effluent likely discharged into a local stream or river within the Lippe or Emscher basin, which ultimately drains into the Rhine River and the North Sea. The closure of the plant may reflect consolidation of wastewater services in the region to improve efficiency and environmental protection.

The plant is situated in the Lippe River basin, a tributary of the Rhine. The Lippe flows through agricultural and urban areas before joining the Rhine near Wesel. The Rhine then discharges into the North Sea via the Rhine-Meuse-Scheldt delta. The region supports diverse aquatic life, including migratory fish species. The closure of the plant may reduce local nutrient loads, benefiting downstream water quality in the Lippe and Rhine.