Unna Billmerich Wastewater Treatment Plant, Unna, Germany

Unna Billmerich is a municipal wastewater treatment plant located in the Ringebrauck district of Unna, in the state of Nordrhein-Westfalen, Germany. The facility serves a population of approximately 2,700 people, classifying it as a small agglomeration under the EU Urban Waste Water Treatment Directive (91/271/EEC). As a German plant serving fewer than 10,000 people, Unna Billmerich is required to provide secondary treatment or equivalent under the EU UWWTD. The regulatory framework ensures that appropriate biological treatment is in place to meet effluent standards for organic matter and suspended solids. The treated effluent from Unna Billmerich is discharged into the local water system, which ultimately drains into the Lippe River, a tributary of the Rhine. The Rhine basin is a major European waterway supporting diverse aquatic life and providing drinking water for millions. The plant's operation helps protect the water quality of the Lippe and Rhine rivers from nutrient pollution and organic loads.

The plant discharges into the local drainage network that flows into the Lippe River, a right-bank tributary of the Rhine. The Lippe River supports a variety of fish species and is part of the Rhine basin, which is ecologically sensitive due to its role as a migratory corridor for fish and its importance for biodiversity. Downstream, the Rhine flows through the Netherlands into the North Sea, making nutrient and pollutant control critical for both freshwater and marine environments.