Johanniskirchen Wastewater Treatment Plant, Bavaria, Germany

The Johanniskirchen wastewater treatment plant is located in the municipality of Johanniskirchen in the Rottal-Inn district of Bavaria, Germany. It serves a population of approximately 2,383 people, classifying it as a small agglomeration under the EU Urban Waste Water Treatment Directive (UWWTD). The plant is situated inland, away from coastal areas. The plant provides secondary treatment, which is the minimum required by the EU UWWTD for freshwater discharges from agglomerations of this size. The designed capacity is 4,980 m³/day, with an average daily discharge volume of about 867 m³/day, indicating a utilization rate well below capacity. As a German facility, it operates under the national Wasserhaushaltsgesetz (WHG) and relevant state regulations, with permits issued by the local water authority. The treated effluent is discharged into a local water body within the Danube river basin, ultimately flowing into the Black Sea. The plant plays a key role in protecting the local watershed from nutrient pollution and organic load, supporting aquatic life in the receiving streams and downstream ecosystems.

The plant discharges into a small watercourse in the Rottal-Inn region, part of the Danube basin. The Danube flows eastward through several countries before reaching the Black Sea. The local watershed supports diverse aquatic habitats and is important for migratory fish species. The plant's secondary treatment helps reduce organic pollution and nutrient loads, contributing to the ecological health of the downstream river system.