Repeses Wastewater Treatment Plant, Viseu, Portugal

Repeses is a wastewater treatment plant located in the Urbanização Vilabeira area of Viseu, Portugal. It serves a population of approximately 4,000 residents in the Repeses e São Salvador parish. The plant is situated inland, away from coastal areas, and operates under Portuguese regulations aligned with the EU Urban Waste Water Treatment Directive. The plant provides secondary treatment, which is the standard required by the EU Urban Waste Water Treatment Directive for agglomerations of this size. Its designed capacity is 5,000 m³/day, and the current discharge volume is 666.92 m³/day, indicating significant spare capacity. Secondary treatment typically involves biological processes to reduce organic matter and suspended solids. The treated effluent is discharged into a local watercourse, which eventually drains into the Vouga River basin and then into the Atlantic Ocean near Aveiro. The plant plays a key role in protecting the local watershed from untreated sewage, supporting water quality in the region's rivers and downstream ecosystems.

The Repeses plant discharges into a tributary of the Vouga River, which flows into the Ria de Aveiro coastal lagoon before reaching the Atlantic Ocean. The Ria de Aveiro is an ecologically sensitive area that supports diverse aquatic life, including fish and bird species. The plant's secondary treatment helps reduce nutrient and organic pollution, mitigating eutrophication risks in the lagoon and coastal waters.