S Romao Wastewater Treatment Plant, Seia, Portugal

S Romao is a wastewater treatment plant located in Carragozela, Seia, in the Guarda district of Portugal. The facility serves a population of approximately 7,500 people, placing it in the small-to-medium agglomeration category under Portuguese and EU regulations. As a plant in Portugal, S Romao operates under the EU Urban Waste Water Treatment Directive (91/271/EEC), which requires secondary treatment for agglomerations of this size. The directive also mandates more advanced treatment if the receiving waters are designated as sensitive areas. The regulatory framework ensures compliance with national and EU standards. The treated effluent from S Romao is discharged into a local watercourse that ultimately drains into the Mondego River basin, one of Portugal's major river systems. The Mondego River flows westward to the Atlantic Ocean near Figueira da Foz, supporting diverse aquatic ecosystems and agricultural water use along its course.

The plant discharges into a tributary of the Mondego River, which flows through central Portugal to the Atlantic Ocean. The Mondego basin supports a variety of freshwater habitats and is important for irrigation and biodiversity. Downstream areas include the Mondego estuary, a coastal wetland that provides nursery grounds for fish and migratory bird habitat. The plant's location inland, over 50 km from the coast, reduces direct marine impact but still influences the river's water quality.