Strass Wastewater Treatment Plant, Spielfeld, Steiermark, Austria

Strass wastewater treatment plant is located in Spielfeld, a municipality in the district of Leibnitz, Steiermark, Austria. The facility serves a population equivalent of approximately 36,029, placing it in the medium agglomeration category under EU classification. As an Austrian plant, Strass operates under the EU Urban Waste Water Treatment Directive (91/271/EEC), which mandates secondary treatment for agglomerations of this size discharging into inland waters. The directive also requires more advanced treatment if the receiving water body is designated as sensitive. Austria has implemented the directive through national legislation, with oversight by the relevant state authority. The plant's treated effluent is discharged into the Mur River, a major tributary of the Drava River, which flows into the Danube and ultimately the Black Sea. The Mur River supports diverse aquatic life and is an important ecological corridor in the region. The plant plays a key role in protecting water quality in the Mur basin and downstream ecosystems.

The plant discharges into the Mur River, which flows through Steiermark and joins the Drava near the Croatian border. The Drava then meets the Danube in Croatia, with the combined flow reaching the Black Sea. The Mur River supports a variety of fish species and is part of a network of rivers that provide habitat for migratory birds and aquatic organisms. The plant's treatment helps maintain the ecological health of this river system.