IDL_BORRO_SANTO Wastewater Treatment Plant, Montespertoli, Tuscany, Italy

IDL_BORRO_SANTO is a wastewater treatment plant located in Montespertoli, a town in the Metropolitan City of Florence, Tuscany, Italy. The plant serves a population of 1,611, classifying it as a small agglomeration under Italian and EU regulations. It operates with primary treatment, which is below the secondary treatment standard typically required for inland discharges under the EU Urban Waste Water Treatment Directive (91/271/EEC). The plant has a designed capacity of 1,300 m³/day and currently discharges 318.92 m³/day, indicating it operates well below its capacity. As a small plant in a rural area, it may be subject to less stringent requirements, but primary treatment alone may not meet the directive's standards for sensitive areas. Primary treatment typically involves physical sedimentation to remove settleable solids. The treated effluent is discharged into a local watercourse that eventually drains into the Arno River basin, which flows through Florence and Pisa before reaching the Tyrrhenian Sea. The Arno River is ecologically significant, supporting diverse aquatic life and providing water for agriculture and industry. The plant's location in the Tuscan hills means its discharge affects small streams that feed into the Arno, making proper treatment important for downstream water quality.

The plant discharges into a tributary of the Arno River, which flows through central Tuscany and empties into the Tyrrhenian Sea near Pisa. The Arno basin is ecologically sensitive, supporting fish species such as the Italian barbel and European eel, and is a key water resource for the region. Primary treatment alone may not adequately reduce nutrients or pathogens, posing risks to downstream aquatic ecosystems and recreational water uses.