Azinhaga Wastewater Treatment Plant, Golegã, Portugal

Azinhaga is a wastewater treatment plant located in the town of Azinhaga, part of the Golegã municipality in the Santarém district of Portugal. The plant serves a population of 1,700 and is currently closed. It is situated inland, away from coastal areas. The plant provided secondary treatment, which is the standard biological treatment required under the EU Urban Waste Water Treatment Directive (91/271/EEC) for agglomerations of this size. The designed capacity was 2,500 cubic meters per day, with a reported discharge volume of 283.44 cubic meters per day. The treated effluent from the plant would have discharged into local watercourses that eventually drain into the Tagus River, one of the major rivers of the Iberian Peninsula, flowing west to the Atlantic Ocean near Lisbon. The Tagus estuary is an ecologically important area supporting diverse aquatic life and migratory bird populations.

The plant is located in the Tagus River basin, which drains a large area of central Portugal and Spain. The Tagus River flows into the Atlantic Ocean via the Tagus Estuary, a vital ecosystem for fish, birds, and other wildlife. The estuary supports important fisheries and serves as a key stopover for migratory birds along the East Atlantic Flyway.