Rehling Wastewater Treatment Plant, Unterach, Bavaria

Rehling wastewater treatment plant is located in Unterach, a district of Rehling in the Bavarian district of Aichach-Friedberg, Germany. The plant serves a population of 2,532 and operates with secondary treatment, a standard level for smaller agglomerations under German and EU regulations. The plant has a designed capacity of 4,600 m³/day and currently discharges 505.60 m³/day of treated wastewater. As a German facility, it operates under the EU Urban Waste Water Treatment Directive (91/271/EEC), which requires secondary treatment for agglomerations between 2,000 and 10,000 population equivalent. The plant's discharge volume indicates it is operating well below its design capacity. The treated effluent is discharged into the local water system, which ultimately drains into the Danube River basin. The plant plays a key role in protecting the region's water quality, supporting the ecological health of the Danube watershed and its downstream environments.

The plant discharges into the Lech River, a tributary of the Danube, which flows into the Black Sea. The Lech River supports diverse aquatic life, including fish species such as grayling and brown trout. The plant's secondary treatment helps reduce organic pollutants and protect the river's ecological balance.