San Paolo Wastewater Treatment Plant, Poggio Mirteto, Lazio, Italy

San Paolo is a wastewater treatment plant located in Poggio Mirteto, a town in the province of Rieti, Lazio, Italy. The facility serves a population of approximately 4,000 residents and operates with advanced treatment processes, ensuring high-quality effluent before discharge. The plant has a designed capacity of 4,000 cubic meters per day and currently treats an average daily flow of 791.86 cubic meters. As an advanced treatment facility, it goes beyond secondary treatment to remove nutrients and other pollutants, meeting stringent Italian and European standards. Under the EU Urban Waste Water Treatment Directive (91/271/EEC), plants serving agglomerations of this size are required to provide secondary treatment, but San Paolo exceeds this baseline with advanced treatment. The treated effluent is discharged into local water bodies that ultimately drain into the Tiber River basin, which flows through Lazio and into the Tyrrhenian Sea. The plant plays a key role in protecting the region's water resources and supporting downstream ecosystems.

The plant discharges into the Tiber River basin, which flows through Lazio and into the Tyrrhenian Sea near Rome. The Tiber River supports diverse aquatic life and is an important water resource for the region. The advanced treatment at San Paolo helps reduce nutrient loading and protects the ecological health of the river and its downstream coastal environment.