Lohmar Donrath Wastewater Treatment Plant, Lohmar, Germany

The Lohmar Donrath wastewater treatment plant is located in the town of Lohmar, within the Rhein-Sieg-Kreis district of Nordrhein-Westfalen, Germany. The plant serves a population of approximately 16,900, 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 agglomerations with a population equivalent between 10,000 and 150,000. The directive also mandates more advanced treatment if the receiving waters are designated as sensitive areas. The plant's treatment process and capacity are aligned with these regulatory standards to ensure compliance with national and EU water quality goals. The treated effluent from the plant is discharged into local watercourses that ultimately drain into the Rhine River basin. The Rhine is a major European waterway that flows through Germany and the Netherlands into the North Sea. The plant plays a key role in protecting the water quality of the Rhine basin, which supports diverse aquatic life and serves as a critical water resource for millions of people.

The plant discharges into the catchment of the Agger River, a tributary of the Sieg River, which flows into the Rhine. The Rhine basin is a densely populated and industrialized region, making wastewater treatment essential for maintaining water quality. The downstream environment includes ecologically sensitive areas that support fish migration and aquatic biodiversity. The plant's operations help reduce nutrient and pollutant loads entering the North Sea via the Rhine.