Quartu S.E. Zone A Mare Loc Rio Foxi Wastewater Treatment Plant, Quartu Sant'Elena, Sardinia

Quartu S.E. Zone A Mare Loc Rio Foxi is an advanced wastewater treatment plant located in Quartu Sant'Elena, on the island of Sardinia, Italy. The plant serves a small population of 350 residents, reflecting its role in a localized coastal community. Its location near the Rio Foxi area places it within the municipality of Quartu Sant'Elena, part of the Metropolitan City of Cagliari. The plant employs advanced treatment processes, which go beyond the secondary treatment standard required by the EU Urban Waste Water Treatment Directive (91/271/EEC) for agglomerations of this size. With a designed capacity of 350 m³/day and an actual discharge volume of 69.29 m³/day, the facility operates well below its capacity, indicating room for future growth or seasonal demand. As an advanced treatment plant, it likely incorporates nutrient removal or other tertiary processes to protect the sensitive coastal environment. The treated effluent is discharged into the local watershed, which ultimately drains into the Tyrrhenian Sea. The plant's proximity to the coast (within 10 km) means its discharge can directly affect marine water quality. Sardinia's coastal ecosystems, including seagrass meadows and rocky reefs, are ecologically sensitive, and advanced treatment helps minimize nutrient loading and other pollutants. The plant plays a key role in safeguarding the bathing waters and marine habitats of the Cagliari Gulf.

The plant discharges into the local drainage network that flows into the Tyrrhenian Sea near the Gulf of Cagliari. This coastal area supports diverse marine life, including Posidonia oceanica seagrass meadows, which are sensitive to nutrient enrichment and turbidity. Advanced treatment at this plant helps reduce the ecological impact on these habitats and maintains water quality for recreational use.