Pettenbach Wastewater Treatment Plant | Oberösterreich, Austria

The Pettenbach wastewater treatment plant is located in the municipality of Pettenbach, in the Bezirk Kirchdorf region of Oberösterreich, Austria. It serves a population of approximately 2,661 residents, placing it in the small agglomeration category under Austrian and EU regulations. The plant employs advanced treatment processes, which go beyond the secondary treatment standard required by the EU Urban Waste Water Treatment Directive (91/271/EEC) for agglomerations of this size. With a designed capacity of 4,487 m³/day and an average daily discharge of 577.67 m³/day, the facility operates well within its capacity. The treated effluent is discharged into local watercourses that ultimately drain into the Danube River basin. The plant's advanced treatment helps protect downstream aquatic ecosystems, including the Danube, which supports diverse fish populations and serves as a critical migratory corridor for species such as sturgeon.

The plant discharges into small streams in the Krems River catchment, which flows into the Danube River near Krems an der Donau. The Danube is a major European waterway that supports rich biodiversity, including over 60 fish species and extensive floodplain forests. The advanced treatment at Pettenbach helps reduce nutrient loading to the Danube, mitigating eutrophication risks in the Black Sea, where the Danube ultimately discharges.