Alcanhoes Vale de Figueira Wastewater Treatment Plant, Santarém, Portugal

Alcanhoes Vale de Figueira is a wastewater treatment plant located in the parish of Alcanhões, within the municipality of Santarém, Portugal. The plant serves a population of approximately 3,200 residents, classifying it as a small agglomeration under Portuguese and EU regulations. It is situated inland, away from coastal areas, and its operations are part of the region's water management infrastructure. The plant provides secondary treatment, which is the standard level required by the EU Urban Waste Water Treatment Directive (91/271/EEC) for freshwater discharges from agglomerations of this size. The designed capacity is 3,700 m³/day, with an average daily discharge volume of about 534 m³, indicating a utilization rate well below capacity. The plant is not subject to the more stringent tertiary treatment requirements that apply to sensitive areas or larger agglomerations. The treated effluent is discharged into local watercourses that eventually drain into the Tagus River basin, one of the major river systems in the Iberian Peninsula. The Tagus River flows westward through Portugal and empties into the Atlantic Ocean near Lisbon. The plant's operations help protect the ecological health of the Tagus watershed, which supports diverse aquatic life and provides water for agriculture and urban use downstream.

The plant discharges into the Tagus River basin, which flows through central Portugal and into the Atlantic Ocean near Lisbon. The Tagus is a major river supporting diverse aquatic ecosystems, including fish species such as the Iberian barbel and the European eel. The watershed also provides critical habitat for migratory birds and is an important water resource for agriculture and urban areas. The plant's secondary treatment helps reduce organic pollution and nutrient loads, contributing to the overall health of the river and its downstream estuary.