Kleines Muhltal Wastewater Treatment Plant, Altenfelden, Austria

Kleines Muhltal is an advanced wastewater treatment plant located in Altenfelden, a municipality in the Bezirk Rohrbach district of Oberösterreich, Austria. The plant serves a population of 1,140 and has a designed capacity of 3,000 m³/day, with an actual discharge volume of 291.63 m³/day. It operates under Austria's implementation of the EU Urban Waste Water Treatment Directive (91/271/EEC), which requires advanced treatment for sensitive areas and secondary treatment as a minimum for agglomerations of this scale. The plant's advanced treatment level ensures high-quality effluent, reducing nutrients and organic pollutants before discharge. As an inland facility, it is not subject to coastal discharge regulations. The plant's capacity utilization is low relative to its design, indicating potential for future growth or seasonal variability. 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 water quality of the region's streams and rivers, supporting aquatic ecosystems and downstream water uses.

The plant discharges into local streams that are part of the Danube River basin, which flows through Central and Eastern Europe before reaching the Black Sea. The receiving waters support diverse aquatic life and are used for recreation and agriculture. The advanced treatment helps minimize nutrient loading, protecting downstream ecosystems from eutrophication.