Fonte Quente Wastewater Treatment Plant, Abrantes, Portugal

Fonte Quente is a wastewater treatment plant located in Alferrarede, Abrantes, in the Santarém district of Portugal. The plant serves a population equivalent of 15,700, classifying it as a medium-sized agglomeration under EU regulations. Its location inland, approximately 50 km from the coast, places it within the Tagus River basin, a major watercourse in the Iberian Peninsula. As a Portuguese facility, Fonte Quente operates under the EU Urban Waste Water Treatment Directive (91/271/EEC), which requires secondary treatment for agglomerations between 10,000 and 150,000 population equivalent discharging into freshwater. The directive also mandates more stringent treatment if the receiving waters are designated as sensitive areas, such as those prone to eutrophication. The regulatory framework ensures compliance with European standards for effluent quality. The treated effluent from Fonte Quente is discharged into the local water system, ultimately flowing into the Tagus River (Tejo), which drains into the Atlantic Ocean near Lisbon. The Tagus River supports diverse aquatic life and is an important ecological corridor for migratory fish species. The plant's operation contributes to protecting water quality in this downstream environment, which includes agricultural and urban areas along the river's course.

Fonte Quente discharges treated wastewater into the local catchment, which drains into the Tagus River (Tejo). The Tagus is the longest river in the Iberian Peninsula, flowing through Spain and Portugal before reaching the Atlantic Ocean at the Tagus Estuary near Lisbon. This estuary is a vital habitat for migratory birds and supports a rich diversity of fish and invertebrates. The plant's location in the Tagus basin means its effluent quality directly affects downstream ecosystems, including areas used for irrigation and recreation.