Montalegre Wastewater Treatment Plant | Montalegre, Portugal

Montalegre wastewater treatment plant is located in Montalegre, Vila Real district, Portugal, serving a population of 2,600. The facility is situated inland, away from coastal areas, and treats municipal wastewater from the local community. The plant provides secondary treatment, which is the standard biological treatment required under the EU Urban Waste Water Treatment Directive (91/271/EEC) for agglomerations of this size. With a designed capacity of 3,732 m³/day and an average discharge volume of 433.50 m³/day, the plant operates well below its capacity, indicating room for future growth or seasonal variations. The treated effluent is discharged into local watercourses that eventually drain into the Atlantic Ocean via the Lima or Cávado river basins. The plant plays a key role in protecting the region's rivers and downstream ecosystems from untreated sewage, supporting water quality and aquatic life in the surrounding watershed.

The plant discharges into the local watershed, which is part of the Lima or Cávado river systems that flow westward to the Atlantic Ocean. This inland region features mountainous terrain and sensitive freshwater habitats that support diverse aquatic species. Proper wastewater treatment is essential to prevent nutrient pollution and maintain the ecological health of these rivers and their downstream estuaries.