Esteveira Wastewater Treatment Plant, Samora Correia, Portugal

Esteveira is an advanced wastewater treatment plant located in Samora Correia, a town in the Santarém district of Portugal. The plant serves a population of approximately 3,800 residents and discharges 633.58 m³/day of treated effluent, with a designed capacity of 8,000 m³/day. As an advanced treatment facility, Esteveira provides a higher level of treatment beyond secondary, which is typical for plants in sensitive areas under the EU Urban Waste Water Treatment Directive (91/271/EEC). Portugal implements this directive through national legislation, requiring appropriate treatment based on the receiving water body's sensitivity. The plant's advanced status suggests it likely employs nutrient removal or other tertiary processes to protect downstream waters. The treated effluent from Esteveira is discharged into the Rio Almansor, a tributary of the Tagus River (Tejo), which flows into the Tagus Estuary near Lisbon and ultimately the Atlantic Ocean. The Tagus Estuary is a vital ecological area supporting diverse aquatic life and migratory birds. The plant's advanced treatment helps minimize nutrient loading and protect this important downstream ecosystem.

Esteveira discharges into the Rio Almansor, which flows into the Tagus River (Tejo), one of the longest rivers in the Iberian Peninsula. The Tagus River empties into the Tagus Estuary near Lisbon, a large and ecologically significant estuary that supports diverse aquatic life, including fish, crustaceans, and migratory birds. The estuary is a critical habitat for many species and is recognized for its ecological importance. Advanced treatment at Esteveira helps reduce nutrient and pollutant loads, contributing to the health of this downstream environment.