OLIVONE BLENIO Wastewater Treatment Plant, Olivone, Ticino, Switzerland

OLIVONE BLENIO is a municipal wastewater treatment plant located in Olivone, a village in the Blenio district of Ticino, Switzerland. The plant serves a population of 898 and is situated in the Swiss Alps, reflecting the region's mountainous terrain and small-scale settlement patterns. The plant provides secondary treatment, which is the standard biological treatment required under Swiss water protection legislation. With a designed capacity of 1,500 m³/day and an average discharge volume of 407.62 m³/day, the facility operates well below its capacity, indicating room for future growth or seasonal variations. Switzerland's strict water protection laws mandate advanced treatment for sensitive areas, but secondary treatment is typical for smaller agglomerations in less sensitive catchments. The treated effluent is discharged into local watercourses that drain into the Brenno River, a tributary of the Ticino River, which ultimately flows into Lake Maggiore and then the Po River system to the Adriatic Sea. The plant plays a key role in protecting the alpine aquatic ecosystem and downstream water quality in the Ticino basin.

The plant discharges into the Brenno River, which flows through the Blenio Valley and joins the Ticino River near Biasca. The Ticino River then enters Lake Maggiore, a large subalpine lake shared with Italy, and continues via the Po River to the Adriatic Sea. The alpine watershed supports diverse aquatic life, including brown trout and other cold-water species, and is sensitive to nutrient loading from wastewater. Secondary treatment helps reduce organic pollution and protect the ecological integrity of this transboundary river system.