WV Millstatter See Wastewater Treatment Plant, Spittal an der Drau, Kärnten

WV Millstatter See is a municipal wastewater treatment plant located in Tangern, Spittal an der Drau, in the state of Kärnten, Austria. It serves a population equivalent of approximately 101,651, classifying it as a large agglomeration under EU regulations. The plant is situated near the scenic Millstätter See lake and the Drau River valley. As a large-scale facility in Austria, the plant operates under the EU Urban Waste Water Treatment Directive (91/271/EEC), which requires secondary treatment as a minimum and tertiary treatment in sensitive areas. The plant's treatment processes are designed to meet stringent Austrian and EU standards for nutrient removal, particularly phosphorus and nitrogen, to protect the receiving waters. The treated effluent is discharged into the Drau River, a major tributary of the Danube. The Drau flows through Carinthia and into Slovenia and Croatia before joining the Danube. The plant plays a critical role in preserving water quality in the Drau basin, which supports diverse aquatic life and is used for recreation and agriculture downstream.

The plant discharges into the Drau River, which flows through the Alpine region of Carinthia and eventually joins the Danube River, ultimately reaching the Black Sea. The Drau basin is ecologically sensitive, supporting fish species such as grayling and brown trout, and is an important corridor for migratory birds. The plant's nutrient removal helps prevent eutrophication in downstream lakes and reservoirs.