ARA Kilchberg_Zeglingen Wastewater Treatment Plant, Kilchberg, Basel-Landschaft

ARA Kilchberg_Zeglingen is a municipal wastewater treatment plant located in Kilchberg, a village in the Basel-Landschaft canton of Switzerland. The plant serves a small population of 402 residents, reflecting its role in a rural or peri-urban setting within the Swiss wastewater infrastructure. The plant employs advanced treatment processes, which typically include biological nutrient removal and possibly tertiary filtration or disinfection, ensuring high-quality effluent. With a designed capacity of 940 m³/day and an average daily discharge of 182.48 m³/day, the plant operates well below its capacity, indicating room for future growth or seasonal variations. The treated effluent is discharged into a local watercourse, likely a tributary of the Rhine River system, which ultimately drains into the North Sea. The plant's advanced treatment helps protect downstream aquatic ecosystems and supports Switzerland's stringent water quality standards under the Swiss Water Protection Act (Gewässerschutzgesetz).

The plant discharges into a small stream in the Ergolz River basin, a tributary of the Rhine. The Rhine flows through Switzerland, Germany, and the Netherlands before reaching the North Sea. The local watershed supports diverse aquatic life, including fish species such as brown trout and grayling, and the advanced treatment ensures minimal nutrient loading, protecting downstream habitats from eutrophication.