Mildenau Wastewater Treatment Plant, Plattenthal, Saxony, Germany

The Mildenau wastewater treatment plant is located in Plattenthal, a district of Mildenau in the Erzgebirgskreis district of Saxony, Germany. It serves a population of approximately 3,900 residents, classifying it as a small to medium agglomeration under EU classification. The plant is situated inland, away from coastal areas, and treats wastewater from the local community. The plant 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. With a designed capacity of 4,000 cubic meters per day and a current discharge volume of 585.00 cubic meters per day, the plant operates well within its capacity. The advanced treatment ensures high-quality effluent, reducing nutrients and pollutants before discharge. The treated effluent is discharged into local watercourses that eventually drain into the Zschopau River, a tributary of the Freiberger Mulde, which flows into the Mulde River and ultimately into the Elbe River. The Elbe drains into the North Sea. The plant plays a key role in protecting the water quality of these rivers and the downstream ecosystem, supporting aquatic life and recreational uses.

The Mildenau plant discharges into local streams that feed the Zschopau River, part of the Elbe River basin. The Elbe flows through Germany and the Czech Republic before reaching the North Sea. The watershed supports diverse aquatic habitats and is important for migratory fish species. Advanced treatment helps minimize nutrient loading, protecting downstream water quality and ecological balance.