Schwanenstadt Wastewater Treatment Plant, Schlatt, Oberösterreich

The Schwanenstadt wastewater treatment plant is located in Schlatt, a municipality in the Bezirk Vöcklabruck district of Oberösterreich, Austria. Serving a population equivalent of 24,883, the plant is part of Austria's municipal wastewater infrastructure, which is regulated under the EU Urban Waste Water Treatment Directive (91/271/EEC). This directive requires secondary treatment for agglomerations between 10,000 and 150,000 population equivalent, and tertiary treatment in sensitive areas. The plant's scale places it in the medium-agglomeration category. Under Austrian implementation of the EU directive, such plants typically employ biological treatment with nutrient removal, especially in the Danube basin where sensitive areas are designated. The population served indicates a facility of moderate size. The plant discharges into the local watershed, which ultimately drains into the Danube River via the Traun River system. The Danube is a major European waterway that flows into the Black Sea, supporting diverse aquatic ecosystems. The region's wastewater treatment contributes to protecting downstream water quality in the Danube Delta, an ecologically sensitive area that supports migratory birds and fish species.

The plant's treated effluent enters the local watercourse, which flows into the Traun River, a tributary of the Danube. The Danube River drains into the Black Sea, supporting a vast watershed that includes ecologically sensitive floodplains and wetlands. The region's aquatic habitats rely on effective nutrient removal to prevent eutrophication and maintain biodiversity, particularly in the downstream Danube Delta.