IDL_STAGNO Wastewater Treatment Plant, Collesalvetti, Toscana

IDL_STAGNO is a wastewater treatment plant located in the Stagno area of Collesalvetti, in the Toscana region of Italy. It serves a population of approximately 4,837 people, placing it in the small agglomeration category under Italian and EU regulations. The plant is situated near the coast, within 10 km of the Tyrrhenian Sea, which influences its operational and environmental considerations. The plant provides secondary treatment, which is the standard required by the EU Urban Waste Water Treatment Directive (91/271/EEC) for agglomerations of this size discharging into coastal waters. Secondary treatment typically involves biological processes to reduce organic matter and suspended solids. The plant has a designed capacity of 8,000 m³/day and currently discharges an average volume of 957.55 m³/day, indicating it operates well below its capacity. The treated effluent is discharged into the local water system, which ultimately drains into the Tyrrhenian Sea. This coastal discharge requires careful management to protect marine water quality and the sensitive ecosystems of the Ligurian Sea. The plant's operation is subject to Italian national regulations implementing the EU directive, ensuring compliance with discharge standards for coastal environments.

The plant discharges treated wastewater into the local drainage network that flows into the Tyrrhenian Sea, a part of the Mediterranean Sea. This coastal area supports diverse marine life, including seagrass meadows and fish nursery habitats. The proximity to the coast necessitates stringent treatment to prevent nutrient enrichment and protect the ecological balance of the marine environment.