Tangstedt Wassermuhle Wastewater Treatment Plant, Tangstedt, Germany

Tangstedt Wassermuhle is an advanced wastewater treatment plant located in Tangstedt, a municipality in the district of Stormarn, Schleswig-Holstein, Germany. The plant serves a population of approximately 5,000 residents, classifying it as a small agglomeration under the EU Urban Waste Water Treatment Directive (UWWTD). It is situated inland, more than 10 km from the coast, and its operations are part of the region's water management infrastructure. The plant employs advanced treatment processes, which go beyond the secondary treatment standard required by the EU UWWTD for agglomerations of this size. Advanced treatment typically includes nutrient removal (nitrogen and phosphorus) to protect sensitive water bodies. The plant has a designed capacity of 4,900 m³/day and reports a discharge volume of 649.78 m³/day, indicating it operates well below its capacity. This suggests the plant is equipped to handle future population growth or seasonal variations. The treated effluent from Tangstedt Wassermuhle is discharged into local streams that flow into the Alster river, a tributary of the Elbe. The Elbe river ultimately drains into the North Sea. The plant plays a key role in protecting the water quality of the Alster and Elbe basins, which support diverse aquatic ecosystems and are used for recreation and drinking water supply downstream.

The plant discharges into small watercourses that feed the Alster river, a tributary of the Elbe river system. The Elbe flows through northern Germany into the North Sea, supporting important estuarine and marine habitats. The region's watershed is ecologically sensitive, with wetlands and floodplains that provide habitat for migratory birds and fish species. Advanced treatment at this plant helps reduce nutrient loading, which is critical for preventing eutrophication in the downstream Elbe estuary and coastal waters.