Alpendurada e Matos douro Wastewater Treatment Plant, Souselo, Portugal

Alpendurada e Matos douro is a wastewater treatment plant located in Souselo, within the municipality of Cinfães, Viseu District, Portugal. The plant serves a population of around 2,500, placing it in the small agglomeration category under Portuguese and EU regulations. The plant provides secondary treatment, which is the standard required by the EU Urban Waste Water Treatment Directive (91/271/EEC) for discharges into freshwater bodies. With a designed capacity of 3,500 cubic meters per day and an average daily flow of approximately 417 cubic meters, the plant operates well below its capacity, indicating room for future growth. The treated effluent is discharged into a local watercourse that eventually flows into the Douro River, one of the major rivers of the Iberian Peninsula. The Douro River supports diverse aquatic life and is an important ecological corridor, ultimately reaching the Atlantic Ocean near Porto. The plant's operation helps protect the water quality of this significant river system.

The plant discharges into a tributary of the Douro River, which flows westward through northern Portugal and into the Atlantic Ocean at Porto. The Douro basin supports a variety of fish species, including migratory fish like the European eel and lamprey. The plant's secondary treatment helps reduce organic pollution and nutrient loads, contributing to the ecological health of the river and its downstream estuary.