Regnitzlosau Wastewater Treatment Plant, Vierschau, Bayern, Germany

The Regnitzlosau wastewater treatment plant is located near Vierschau in the Bavarian district of Hof, Germany. It serves a population of approximately 3,675, placing it in the small agglomeration category under the EU Urban Waste Water Treatment Directive (91/271/EEC). The plant is situated inland, away from coastal areas, and treats wastewater from the local community. The facility employs advanced treatment processes, which go beyond the secondary treatment standard required by the EU directive for smaller agglomerations. Advanced treatment typically includes nutrient removal (nitrogen and phosphorus) to protect sensitive water bodies. The plant's designed capacity is 7,000 m³/day, and it currently discharges an average of 930 m³/day, indicating ample capacity for future growth. The treated effluent is discharged into local watercourses that eventually drain into the Saale River basin, a tributary of the Elbe River. The Elbe flows into the North Sea, making the plant's advanced treatment important for reducing nutrient loads that could contribute to eutrophication in downstream waters. The region's water bodies support diverse aquatic life and are used for recreation and agriculture.

The plant discharges into local streams that feed the Saale River, a major tributary of the Elbe River. The Elbe flows through Germany and the Czech Republic before emptying into the North Sea. The watershed supports diverse aquatic ecosystems, including fish species such as salmon and trout, and is an important migratory corridor. Advanced treatment at Regnitzlosau helps reduce nutrient pollution that could otherwise contribute to algal blooms and oxygen depletion in downstream waters.