Espicandeira Wastewater Treatment Plant, Alenquer, Portugal

The Espicandeira wastewater treatment plant is located in Alenquer, Lisbon District, Portugal, serving a population of approximately 4,620. The facility provides secondary treatment, a standard level for smaller agglomerations under Portuguese and EU regulations. With a designed capacity of 5,600 cubic meters per day, the plant currently treats an average daily flow of 770.30 cubic meters, indicating significant reserve capacity. As a secondary treatment plant, Espicandeira meets the requirements of the EU Urban Waste Water Treatment Directive (91/271/EEC), which mandates secondary biological treatment for agglomerations with a population equivalent above 2,000. The plant's operational context is shaped by Portugal's implementation of this directive, with regulatory oversight from the Portuguese Environment Agency (APA) and local water authorities. The treated effluent is discharged into the local watershed, which ultimately drains into the Tagus River basin. The Tagus River flows westward through central Portugal and into the Atlantic Ocean near Lisbon. The downstream environment supports diverse aquatic life and is an important ecological corridor. The plant's location inland, more than 10 km from the coast, reduces direct marine impact, but its discharge contributes to the overall water quality of the Tagus estuary.

The Espicandeira plant discharges into the Tagus River basin, which flows into the Atlantic Ocean via the Tagus estuary near Lisbon. The estuary is a vital habitat for migratory birds and fish species, including the European eel and various waterfowl. The plant's secondary treatment helps reduce organic pollution and nutrient loads, supporting the ecological health of the downstream environment.