Cugnana Verde Wastewater Treatment Plant, Olbia, Sardinia

Cugnana Verde is an advanced wastewater treatment plant located in the Cugnana Verde district of Olbia, in the Sardinia region of Italy. The plant serves a population of 3,363 people and has a designed capacity of 4,200 m³/day, with an average discharge volume of 665.76 m³/day. As an advanced treatment facility, Cugnana Verde provides tertiary-level purification beyond secondary biological treatment, typically including nutrient removal or disinfection. This level of treatment is consistent with Italy's implementation of the EU Urban Waste Water Treatment Directive (91/271/EEC), which requires advanced treatment for discharges into sensitive areas or for agglomerations serving over 10,000 population equivalent. Although the plant serves fewer than 10,000 people, its advanced treatment reflects local environmental requirements. The plant is situated within 10 km of the coast, indicating that treated effluent likely discharges into a coastal water body or a river that flows into the Tyrrhenian Sea. The surrounding area is part of the Gallura region, known for its scenic coastline and tourism. The plant's advanced treatment helps protect the marine environment and supports the ecological health of the nearby coastal waters.

The plant discharges into a coastal environment near Olbia, on the northeastern coast of Sardinia. The treated effluent likely enters the Tyrrhenian Sea via a local watercourse or directly through a marine outfall. This area supports diverse marine life, including seagrass meadows and fish habitats, and is important for local fisheries and tourism. Advanced treatment reduces nutrient loads, helping to prevent eutrophication and maintain water quality in the sensitive coastal ecosystem.