HORNUSSEN Wastewater Treatment Plant, Böztal, Aargau, Switzerland

HORNUSSEN is a wastewater treatment plant located in the municipality of Böztal, within the canton of Aargau, Switzerland. The plant serves a population of around 2,858 residents, making it a small-scale facility typical of rural Swiss communities. It operates under Swiss water protection legislation, which aligns with the EU Urban Waste Water Treatment Directive (91/271/EEC) through bilateral agreements, ensuring high environmental standards. As a small agglomeration, the plant is expected to provide secondary treatment or equivalent to meet Swiss water quality requirements. The facility is part of Switzerland's decentralized wastewater infrastructure, which emphasizes local treatment to protect sensitive water bodies. Swiss regulations mandate effective nutrient removal to safeguard receiving waters. The treated effluent is discharged into local waterways that drain into the Rhine River basin, ultimately reaching the North Sea. The plant plays a key role in protecting the aquatic ecosystems of the Aargau region, which includes diverse habitats for fish and invertebrates. Its operation supports the ecological health of downstream environments, including the Rhine, a major European waterway.

The plant discharges into local streams that flow into the Rhine River, which passes through Switzerland, Germany, and the Netherlands before reaching the North Sea. The Rhine basin supports diverse aquatic life, including migratory fish species. The plant's treatment helps maintain water quality in this ecologically sensitive river system, which is vital for drinking water, recreation, and biodiversity.