St. Radegund Wastewater Treatment Plant, Steiermark, Austria

The St. Radegund wastewater treatment plant is located in the municipality of St. Radegund in the Bezirk Graz-Umgebung district of Steiermark, Austria. It serves a population of approximately 1,325 residents, classifying it as a small agglomeration under Austrian and EU wastewater 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 2,500 m³/day and an actual discharge volume of 279.36 m³/day, the plant operates well below its capacity, indicating room for future growth or seasonal variations. The treated effluent is discharged into local watercourses that ultimately drain into the Mur River, a major tributary of the Drava and Danube river systems. The plant's advanced treatment helps protect the sensitive aquatic ecosystems of the Mur basin, which supports diverse fish populations and is an important corridor for migratory species.

The plant discharges into small streams that flow into the Mur River, which joins the Drava near the Croatian border and eventually reaches the Danube River and the Black Sea. The Mur basin is ecologically sensitive, supporting species such as the Danube salmon (Hucho hucho) and providing critical habitat for aquatic biodiversity. Advanced treatment at this plant helps reduce nutrient loads and protect downstream water quality.