Graz Gossendorf Wastewater Treatment Plant: Serving Graz, Austria

Graz Gossendorf is a major wastewater treatment plant located in Abtissendorf, near Graz in the state of Styria, Austria. Serving a population equivalent of 515,612, it is one of the largest treatment facilities in the region, handling municipal wastewater from the Graz metropolitan area. As a large agglomeration under the EU Urban Waste Water Treatment Directive (91/271/EEC), the plant is required to provide at least secondary treatment, with tertiary treatment likely implemented to meet sensitive area standards. The plant's design capacity and treatment processes are aligned with Austrian regulations, which mandate advanced nutrient removal for discharges into sensitive water bodies. The treated effluent is discharged into the Mur River, which flows through Graz and continues southeast into Slovenia and Croatia before reaching the Drava and ultimately the Danube River and Black Sea. The plant plays a critical role in protecting the Mur River's water quality, supporting aquatic life and downstream ecosystems.

The plant discharges into the Mur River, a major tributary of the Drava, which flows into the Danube and eventually the Black Sea. The Mur River supports diverse aquatic life, including fish species such as grayling and brown trout, and is an important corridor for migratory birds. The plant's advanced treatment helps maintain the river's ecological health, particularly downstream in the sensitive floodplain areas.