CADRO MEDIO CASSARATE Wastewater Treatment Plant, Lugano, Switzerland

CADRO MEDIO CASSARATE is a wastewater treatment plant located in the Cadro district of Lugano, in the canton of Ticino, Switzerland. Serving a population of around 9,644, it is part of the municipal wastewater infrastructure for the Lugano area, which lies in the southern Alpine region near the Italian border. As a Swiss plant, it operates under the Federal Water Protection Act (GSchG) and the Water Protection Ordinance (GSchV), which mandate appropriate treatment for all wastewater discharges. For a plant of this scale, secondary treatment with nutrient removal is typically required to protect sensitive water bodies. Swiss regulations ensure compliance with stringent effluent standards. The treated effluent from this plant ultimately discharges into the Cassarate River, which flows through Lugano and into Lake Lugano (Lago di Lugano). Lake Lugano is a subalpine lake shared with Italy and is part of the Po River basin, draining into the Adriatic Sea. The lake is ecologically sensitive, supporting diverse aquatic life and serving as a key water resource for the region.

The plant's treated effluent enters the Cassarate River, a short river that flows through Lugano and empties into Lake Lugano. Lake Lugano is part of the Po River basin, which drains into the Adriatic Sea. The lake is a deep subalpine lake with sensitive ecology, including endemic fish species and important migratory bird habitats. Nutrient loading from wastewater can contribute to eutrophication, so effective treatment is critical for maintaining water quality in this transboundary water body.