TRIEI Wastewater Treatment Plant, Triei, Sardinia, Italy

TRIEI is a wastewater treatment plant located in Triei, a town in the Ogliastra province of Sardinia, Italy. The facility serves a population of approximately 3,565 residents, reflecting a small to medium agglomeration. It operates under Italy's implementation of the EU Urban Waste Water Treatment Directive (91/271/EEC), which mandates appropriate treatment levels for sensitive areas. The plant provides advanced treatment, which goes beyond the secondary treatment standard required by the EU directive for most agglomerations. This level of treatment is typically employed to reduce nutrients like nitrogen and phosphorus, protecting sensitive receiving waters. The plant has a designed capacity of 4,000 cubic meters per day and currently discharges about 706 cubic meters daily, indicating ample reserve capacity. The treated effluent is released into the local watershed, which ultimately drains into the Tyrrhenian Sea. Sardinia's coastal ecosystems are ecologically sensitive, supporting diverse marine life and seagrass meadows. The advanced treatment helps minimize nutrient loading and protects the coastal water quality, which is vital for tourism and fisheries in the region.

The plant discharges into the local drainage basin that flows to the Tyrrhenian Sea, a part of the Mediterranean Sea. The coastal waters near Triei support diverse marine habitats, including seagrass beds and rocky reefs, which are sensitive to nutrient pollution. Advanced treatment at the plant reduces the risk of eutrophication and helps maintain the ecological balance of this coastal environment.