Polling Wastewater Treatment Plant, Bavaria, Germany - Secondary Treatment for Small Community

Polling wastewater treatment plant is located in the municipality of Polling, in the district of Mühldorf am Inn, Bavaria, Germany. The plant serves a population of approximately 2,400 residents, classifying it as a small agglomeration under the EU Urban Waste Water Treatment Directive (91/271/EEC). The plant provides secondary treatment, which is the minimum required by the EU directive for freshwater discharges from agglomerations of this size. Its designed capacity is 3,000 m³/day, with an average daily discharge volume of about 610 m³/day, indicating a utilization rate well below capacity. The treated effluent is discharged into a local watercourse that ultimately drains into the Inn River, a major tributary of the Danube. The Danube basin supports diverse aquatic ecosystems and is an important migratory corridor for fish species. The plant's secondary treatment helps protect downstream water quality in this ecologically sensitive river system.

The plant discharges into a small receiving water body that flows into the Inn River, which joins the Danube near Passau. The Danube is a major European river supporting diverse aquatic life and serving as a critical migratory corridor for fish such as sturgeon. The Inn River itself is ecologically important, with sections designated as sensitive areas under the EU Water Framework Directive. Secondary treatment at this plant helps reduce organic pollution and nutrient loads, contributing to the ecological health of the downstream watershed.