Suderbrarup Wastewater Treatment Plant, Süderbrarup, Schleswig-Holstein, Germany

The Suderbrarup wastewater treatment plant is located in the municipality of Süderbrarup, in the Schleswig-Flensburg district of Schleswig-Holstein, Germany. It serves a population of approximately 5,200, classifying it as a small to medium agglomeration under German and EU regulations. The plant employs advanced treatment, which goes beyond the EU Urban Waste Water Treatment Directive's minimum requirement of secondary treatment for this population tier. Advanced treatment typically includes nutrient removal (nitrogen and phosphorus) to protect sensitive receiving waters. The plant has a designed capacity of 6,000 m³/day and currently treats an average daily flow of about 649 m³, indicating ample reserve capacity. Treated effluent is discharged into local streams that drain into the Schlei inlet, a Baltic Sea fjord. The Schlei is an ecologically sensitive brackish water body supporting diverse aquatic life and migratory birds. The plant's advanced treatment helps reduce nutrient loads that could otherwise contribute to eutrophication in the Baltic Sea.

The plant discharges into small watercourses that flow into the Schlei, a narrow Baltic Sea inlet in Schleswig-Holstein. The Schlei is a nutrient-sensitive brackish ecosystem that supports fish spawning, waterfowl, and unique flora. Its connection to the Baltic Sea means that nutrient removal at the plant helps mitigate eutrophication in the broader Baltic region, which is a priority under the Helsinki Convention (HELCOM).