BUHL Wastewater Treatment Plant, Buhl, Grand Est, France

The BUHL wastewater treatment plant is located in Buhl, a commune in the Bas-Rhin department of the Grand Est region in northeastern France. It serves a population of approximately 4,100 residents, making it a small agglomeration under French and EU classification. The plant is situated near the German border, within the Upper Rhine plain. The facility employs advanced treatment processes, which go beyond the secondary treatment required by the EU Urban Waste Water Treatment Directive (91/271/EEC) for agglomerations of this size. Advanced treatment typically includes nutrient removal (nitrogen and phosphorus) to protect sensitive water bodies. The plant has a designed capacity of 4,650 m³/day and currently discharges 731.43 m³/day of treated wastewater, indicating significant spare capacity. The treated effluent is discharged into local streams that flow into the Sauer River, a tributary of the Rhine. The Rhine basin is a major European waterway supporting diverse aquatic ecosystems and providing drinking water for millions. The advanced treatment helps minimize nutrient loading and protects downstream water quality in the Rhine and its delta.

The plant discharges into the Sauer River catchment, which flows into the Rhine River. The Rhine is a transboundary river that ultimately reaches the North Sea via the Rhine-Meuse-Scheldt delta. This watershed supports diverse aquatic life, including migratory fish species such as salmon and eel. Advanced treatment at BUHL reduces nutrient pollution, helping to prevent eutrophication in downstream lakes and coastal zones.