ARA Rauris - Advanced Wastewater Treatment Plant in Rauris, Salzburg

ARA Rauris is an advanced wastewater treatment plant located in Hundsdorf, near Rauris, in the state of Salzburg, Austria. The plant serves a population of approximately 8,095 people, reflecting its role in managing municipal wastewater for this Alpine community. The plant employs advanced treatment processes, which go beyond secondary treatment to remove nutrients and other pollutants. With a designed capacity of 10,500 m³/day and an actual discharge volume of about 698 m³/day, the facility operates well within its capacity. As an Austrian plant, it operates under the EU Urban Waste Water Treatment Directive (91/271/EEC), which mandates advanced treatment for sensitive areas. The treated effluent is discharged into local watercourses that eventually drain into the Salzach River, a tributary of the Inn River, which flows into the Danube and ultimately the Black Sea. The plant plays a key role in protecting the sensitive Alpine aquatic environment and downstream ecosystems.

The plant discharges into small streams in the Rauris valley, which feed into the Salzach River. The Salzach flows north through the Alps, joining the Inn River near Braunau, then the Danube, and finally the Black Sea. The surrounding watershed is ecologically sensitive, supporting diverse aquatic life and serving as an important corridor for migratory fish species. Advanced treatment helps minimize nutrient loading in these pristine Alpine waters.