Altertheim Wastewater Treatment Plant, Steinbach, Bayern

Altertheim is a municipal wastewater treatment plant located in Steinbach, part of the Altertheim area in the district of Würzburg, Bayern, Germany. The plant serves a population of approximately 2,154 people, classifying it as a small agglomeration under the EU Urban Waste Water Treatment Directive (UWWTD). The plant provides secondary treatment, which is the minimum required by the EU UWWTD for freshwater discharges from agglomerations of this size. With a designed capacity of 4,000 m³/day and an average discharge volume of 545.13 m³/day, the plant operates well below its capacity, indicating room for future growth or seasonal variations. The treated effluent is discharged into local watercourses that eventually drain into the Main River, a major tributary of the Rhine. The Rhine basin is ecologically significant, supporting diverse aquatic life and serving as a critical migratory corridor for fish species. The plant's secondary treatment helps protect downstream water quality in this sensitive river system.

The plant discharges into small streams that flow into the Main River, which joins the Rhine near Mainz. The Rhine basin is a vital European waterway, supporting rich biodiversity and providing drinking water for millions. Downstream, the Rhine flows through the Rhine Delta into the North Sea. The region's agricultural and urban runoff can contribute nutrient loads, making the plant's secondary treatment important for controlling eutrophication risks in the river and coastal waters.