SKA Unterkirnach Wastewater Treatment Plant, Unterkirnach, Baden-Württemberg

SKA Unterkirnach is an advanced wastewater treatment facility located in the Kirnachtal valley of Unterkirnach, within the Schwarzwald-Baar-Kreis district of Baden-Württemberg, Germany. The plant serves a population of approximately 3,450 residents and is designed to handle a capacity of 4,400 cubic meters per day, with an average discharge volume of 781.67 m³/day. As an advanced treatment plant, SKA Unterkirnach goes beyond secondary treatment to remove nutrients such as nitrogen and phosphorus, ensuring high effluent quality. This level of treatment is typical for plants in sensitive areas under the EU Urban Waste Water Treatment Directive (91/271/EEC), which requires advanced treatment for agglomerations discharging into sensitive water bodies. The treated effluent from SKA Unterkirnach is discharged into the local water system, which ultimately drains into the Danube River basin via the Brigach and Danube rivers. The plant plays a crucial role in protecting the water quality of the Kirnach stream and downstream aquatic ecosystems, supporting biodiversity in the Black Forest region.

SKA Unterkirnach discharges into the Kirnach stream, a tributary of the Brigach River, which joins the Breg to form the Danube River. The Danube flows eastward through Central and Eastern Europe before reaching the Black Sea. The plant's advanced treatment helps protect sensitive freshwater ecosystems in the upper Danube basin, including habitats for fish and macroinvertebrates. The region's forested landscape and reliance on groundwater make nutrient removal critical for preventing eutrophication in downstream waters.