StMichael Wastewater Treatment Plant, Sankt Michael in Obersteiermark, Austria

StMichael wastewater treatment plant is located in Sankt Michael in Obersteiermark, in the state of Steiermark, Austria. The plant serves a population of around 18,000 people, classifying it as a medium agglomeration under EU regulations. As an Austrian plant, StMichael is subject to the EU Urban Waste Water Treatment Directive (91/271/EEC), which requires secondary treatment for agglomerations of this size. The directive also mandates more advanced treatment if the receiving waters are sensitive areas. It is expected to meet these EU standards. The treated effluent from StMichael is discharged into local waterways that ultimately drain into the Danube River basin and then into the Black Sea. The plant plays a key role in protecting the local aquatic environment and downstream ecosystems from pollution.

StMichael's treated wastewater flows into the Mur River, a major tributary of the Drava River, which joins the Danube and eventually reaches the Black Sea. The local watershed supports diverse aquatic life and is an important ecological corridor. The plant's operation helps maintain water quality in this sensitive river system.