ARA Dienten - Advanced Wastewater Treatment in Höfl-Zachhof, Salzburg

ARA Dienten is an advanced wastewater treatment plant located in Höfl-Zachhof, a locality in the municipality of Dienten am Hochkönig, Bezirk Zell am See, Salzburg, Austria. The plant serves a population of 2,433, placing it in the small agglomeration category under the EU Urban Waste Water Treatment Directive (UWWTD). The plant employs advanced treatment processes, which go beyond secondary treatment to remove nutrients such as nitrogen and phosphorus. With a designed capacity of 3,800 cubic meters per day and an actual discharge volume of 374.93 cubic meters per day, the plant operates well below its capacity, indicating room for future growth or seasonal variations. The treated effluent is discharged into the local watershed, which drains into the Salzach River and ultimately the Danube River basin. This contributes to the protection of the Danube's ecological health, supporting diverse aquatic life and downstream ecosystems.

The plant discharges into the local watershed that feeds the Salzach River, a tributary of the Inn River, which flows into the Danube. The Danube is a major European waterway supporting diverse aquatic ecosystems, including fish species such as sturgeon and migratory birds. The advanced treatment at ARA Dienten helps reduce nutrient loading, protecting downstream water quality in the sensitive Danube basin.