Termas S Vicente Wastewater Treatment Plant, Penafiel, Portugal

Termas S Vicente is an advanced wastewater treatment plant located in Várzea, Termas de São Vicente, Penafiel, in the Porto district of Portugal. The plant serves a population of 4,500 and has a designed capacity of 8,000 m³/day, with an average discharge volume of 750.29 m³/day, indicating it operates well below its capacity. The plant employs advanced treatment processes, which go beyond secondary treatment to remove nutrients and other pollutants. As a facility in Portugal, it operates under the EU Urban Waste Water Treatment Directive (91/271/EEC), which requires advanced treatment for sensitive areas and agglomerations of this scale discharging into sensitive waters. The treated effluent is discharged into the local watershed, which ultimately drains into the Douro River basin and then into the Atlantic Ocean. The plant's advanced treatment helps protect the downstream aquatic environment, supporting water quality and biodiversity in the region.

The plant discharges into the Douro River basin, which flows westward through northern Portugal and into the Atlantic Ocean near Porto. The Douro estuary and coastal zone support diverse aquatic life, including migratory fish species such as salmon and lamprey. Advanced treatment at this plant helps reduce nutrient loading, protecting the ecological health of the river and the marine environment.