ARA GAV Kleinharraserbach 3366 GF Wastewater Treatment Plant, Matzen-Raggendorf, Austria

ARA GAV Kleinharraserbach 3366 GF is a wastewater treatment plant located in the municipality of Matzen-Raggendorf, in the Bezirk Gänserndorf of Niederösterreich, Austria. The plant serves a population of 1,350 and operates with secondary treatment, a standard level for smaller agglomerations under Austrian and EU regulations. With a designed capacity of 6,000 m³/day and an actual discharge volume of 605.60 m³/day, the plant operates well below its capacity. As an Austrian facility, it falls under the EU Urban Waste Water Treatment Directive (91/271/EEC), which requires secondary treatment for agglomerations above 2,000 population equivalent, though Austria applies stringent standards across all scales. The treated effluent is discharged into local watercourses that drain into the Danube River basin, ultimately reaching the Black Sea. The plant plays a key role in protecting the region's groundwater and surface water quality, supporting the ecological health of the Marchfeld area and downstream aquatic habitats.

The plant discharges into local streams that feed into the Danube River basin, which flows into the Black Sea. The Marchfeld region is an important agricultural area with sensitive groundwater resources. The plant's secondary treatment helps reduce nutrient loads, protecting downstream aquatic ecosystems and supporting biodiversity in the Danube floodplains.