ARA Melk 159 ME Wastewater Treatment Plant, Emmersdorf an der Donau, Austria

ARA Melk 159 ME is a wastewater treatment plant located in Emmersdorf an der Donau, a municipality in the Melk district of Lower Austria. The plant serves a population of approximately 5,336 people, placing it in the small to medium agglomeration category under EU classification. As an Austrian plant, ARA Melk 159 ME 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 designated as sensitive areas. The plant is expected to meet these regulatory standards. The plant discharges treated wastewater 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 millions of people. The plant's operations contribute to protecting water quality in this important river system.

The plant's treated effluent enters the local tributary network that feeds into the Danube River near Melk. The Danube is a transboundary river that flows through multiple countries before reaching the Black Sea. This stretch of the Danube supports diverse aquatic life, including fish species such as Danube salmon and various migratory birds. The region is also known for its agricultural activity, making nutrient management important for preventing eutrophication downstream.