Mondim de Basto Wastewater Treatment Plant, Celorico de Basto, Portugal

Mondim de Basto is a wastewater treatment plant located in Celorico de Basto, in the Braga district of northern Portugal. The plant serves a population of approximately 3,400 people, providing secondary treatment to municipal wastewater. It is situated inland, away from coastal areas, and operates as part of the region's sanitation infrastructure. The plant has a designed capacity of 5,000 m³/day and currently discharges an average of 566.88 m³/day of treated effluent. As a secondary treatment facility, it meets the standard requirements for organic matter and suspended solids removal. Under Portuguese and EU regulations, plants serving agglomerations of this size are expected to comply with the EU Urban Waste Water Treatment Directive (91/271/EEC), which mandates secondary treatment for inland discharges. The treated effluent is discharged into local watercourses that eventually drain into the Douro River basin, one of the major river systems in the Iberian Peninsula. The Douro River flows westward through Portugal and empties into the Atlantic Ocean near Porto. The plant's operations help protect the water quality of these downstream environments, supporting aquatic life and recreational uses.

The plant discharges into local streams that are part of the Douro River basin, which flows into the Atlantic Ocean. The Douro River supports diverse aquatic ecosystems and is an important water resource for agriculture and urban areas. The secondary treatment provided by the plant reduces organic pollutants and suspended solids, helping to maintain the ecological health of the receiving waters and downstream environments.