Vila Viçosa Wastewater Treatment Plant - Secondary Treatment in Évora, Portugal

The Vila Viçosa wastewater treatment plant is located in the town of Vila Viçosa, within the Évora district of Portugal. It serves a population of approximately 5,100 residents, providing secondary treatment for municipal wastewater. The plant has a designed capacity of 7,500 m³/day and currently discharges an average of 850.33 m³/day of treated effluent. As a secondary treatment facility, the plant meets the requirements of the EU Urban Waste Water Treatment Directive (91/271/EEC), which mandates secondary biological treatment for agglomerations of this size. The plant's capacity utilization is low, indicating ample headroom for future growth or seasonal variations. The regulatory framework in Portugal is enforced by the Portuguese Environment Agency (APA), ensuring compliance with national and EU standards. The treated effluent is discharged into the local watershed, which ultimately drains into the Guadiana River basin. The Guadiana River flows southward, forming part of the border between Portugal and Spain before emptying into the Gulf of Cádiz in the Atlantic Ocean. The downstream environment supports diverse aquatic life and is an important ecological corridor in the Iberian Peninsula.

The Vila Viçosa plant discharges into the Guadiana River basin, which flows through the Alentejo region and eventually reaches the Atlantic Ocean via the Gulf of Cádiz. The Guadiana River supports a variety of fish species, including the endangered Iberian barbel, and its estuary is a critical habitat for migratory birds. The plant's secondary treatment helps protect water quality in this ecologically sensitive watershed.