FIEZ Wastewater Treatment Plant, Fiez, Vaud, Switzerland

FIEZ is an advanced wastewater treatment plant located in the municipality of Fiez, within the District du Jura-Nord vaudois in the canton of Vaud, Switzerland. The plant serves a small population of 455 residents, reflecting its role in a rural or small community setting. Its location in the Swiss Jura region places it within a landscape of rolling hills and agricultural areas. The plant operates with advanced treatment technology, which goes beyond the secondary treatment standard required by Swiss regulations for smaller agglomerations. Under Swiss water protection law (Gewässerschutzgesetz), all wastewater treatment plants must meet strict effluent quality standards, and advanced treatment often includes nutrient removal to protect sensitive water bodies. The plant has a designed capacity of 1000 cubic meters per day, with a current discharge volume of 206.53 cubic meters per day, indicating ample reserve capacity. The treated effluent from FIEZ is discharged into the local hydrological network, which ultimately drains into the Rhone River basin via the Arnon or other tributaries. The Rhone flows through Lake Geneva and into the Mediterranean Sea, making the plant's advanced treatment important for protecting downstream aquatic ecosystems, including Lake Geneva, which is a major freshwater resource and ecologically sensitive area supporting diverse fish and bird life.

The FIEZ plant discharges into the local watershed that feeds into the Rhone River basin, which flows through Lake Geneva and eventually reaches the Mediterranean Sea. The advanced treatment level helps protect downstream water quality in this ecologically sensitive region, where Lake Geneva supports diverse aquatic life and serves as a critical freshwater resource. The surrounding Jura region features karstic geology, making groundwater protection particularly important.