Villesse Wastewater Treatment Plant, Friuli-Venezia Giulia, Italy

The Villesse wastewater treatment plant is located in the municipality of Villesse (Vilès) in the Friuli-Venezia Giulia region of northeastern Italy. The facility serves a population of approximately 1,572 and operates with advanced treatment processes, reflecting a high standard of effluent quality. The plant's designed capacity is 5,000 m³/day, with a current discharge volume of 626.92 m³/day. As an advanced treatment plant, Villesse goes beyond the secondary treatment requirements set by the EU Urban Waste Water Treatment Directive (91/271/EEC) for agglomerations of this size. The directive mandates secondary treatment for populations between 2,000 and 10,000, but Italy has implemented advanced treatment in sensitive areas to protect coastal and lagoon ecosystems. The plant's permit and operational oversight fall under Italian national regulations, which align with EU standards. The treated effluent is discharged into local watercourses that drain into the Adriatic Sea, a semi-enclosed basin with high ecological sensitivity. The plant's proximity to the coast (within 10 km) means its discharge contributes to the nutrient and pollutant load entering the northern Adriatic, which is subject to eutrophication risks. Advanced treatment helps mitigate these impacts by reducing nitrogen and phosphorus levels.

The Villesse plant discharges into the Isonzo River basin, which flows into the Gulf of Trieste in the northern Adriatic Sea. This coastal area is ecologically sensitive due to its shallow depth, limited water exchange, and vulnerability to nutrient enrichment. The advanced treatment at Villesse helps protect downstream habitats, including seagrass beds and fish nursery grounds, by reducing organic and nutrient loads.