IDL_FORMELLE_PIANCASTAGNAIO Wastewater Treatment Plant, Piancastagnaio, Tuscany

IDL_FORMELLE_PIANCASTAGNAIO is a municipal wastewater treatment plant located in Piancastagnaio, a town in the Unione dei Comuni Amiata Val d'Orcia, in the province of Siena, Tuscany, Italy. The plant serves a population of approximately 4,671 and has a designed capacity of 5,000 cubic meters per day, with a current discharge volume of 924.69 cubic meters per day. 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. Under this directive, secondary treatment is mandatory for populations between 2,000 and 10,000, ensuring removal of organic matter and suspended solids before discharge. The treated effluent is discharged into the local watershed, which ultimately drains into the Tyrrhenian Sea via the Paglia and Tiber rivers. The plant plays a key role in protecting the water quality of the surrounding environment, including the Orcia Valley, a region known for its agricultural and ecological value.

The plant discharges into the local drainage network that feeds the Paglia River, a tributary of the Tiber River, which flows into the Tyrrhenian Sea. The Orcia Valley is a sensitive agricultural and ecological area, and the plant's secondary treatment helps reduce nutrient and organic pollution, supporting the health of downstream aquatic ecosystems.