Santa Comba Dao Wastewater Treatment Plant, Santa Comba Dão, Portugal

Santa Comba Dao is a wastewater treatment plant located in Santa Comba Dão, Viseu District, Portugal. It serves a population of approximately 3,900 residents, classifying it as a small agglomeration under the EU Urban Waste Water Treatment Directive (91/271/EEC). The plant is situated inland, away from coastal areas, and treats municipal wastewater from the local community. The plant provides secondary treatment, which is the minimum standard required by the EU Directive for freshwater discharges from agglomerations of this size. With a designed capacity of 6,100 m³/day and an actual discharge volume of 650.25 m³/day, the plant operates well below its capacity, indicating potential for future growth or seasonal variations. Secondary treatment typically involves biological processes to reduce organic matter and suspended solids. The treated effluent is discharged into the local watershed, which ultimately drains into the Mondego River basin. The Mondego River is one of Portugal's major rivers, flowing through the central region and emptying into the Atlantic Ocean near Figueira da Foz. The plant's operations help protect the water quality of the Mondego River and its downstream ecosystems, supporting aquatic life and recreational uses.

The plant discharges into the Mondego River basin, which flows through central Portugal and reaches the Atlantic Ocean. The Mondego River supports diverse aquatic life and is important for irrigation and recreation. The secondary treatment provided by the plant reduces organic pollutants and suspended solids, helping to maintain the ecological health of the river and its estuary.