ARA GAV Mittleres Schmidatal Wastewater Treatment Plant, Großwiesendorf, Austria

ARA GAV Mittleres Schmidatal is a municipal wastewater treatment plant located in Großwiesendorf, within the district of Tulln in Niederösterreich, Austria. The plant serves a population equivalent of approximately 12,965 people, placing it in the medium agglomeration category under EU classification. As an Austrian facility, the plant operates under the EU Urban Waste Water Treatment Directive 91/271/EEC, which requires secondary treatment for agglomerations of this size. The directive also mandates more stringent treatment if the receiving waters are designated as sensitive areas. The plant's treatment processes are designed to meet these regulatory standards. The treated effluent is discharged into the local water system, which ultimately drains into the Danube River basin. The Danube is a major European waterway that flows into the Black Sea, supporting diverse aquatic ecosystems and providing water for agriculture and industry along its course.

The plant's discharge enters the Schmidatal region, a tributary of the Danube River basin. The Danube is one of Europe's most important rivers, flowing through multiple countries before reaching the Black Sea. The watershed supports a variety of fish species and provides critical habitat for migratory birds. The plant's operations help protect downstream water quality in this ecologically significant river system.