Serpa Wastewater Treatment Plant, Serpa, Portugal - Advanced Treatment for 5,000 People

The Serpa wastewater treatment plant is located in the parish of Salvador e Santa Maria, in the municipality of Serpa, Beja district, Portugal. It serves a population of approximately 5,000 people, making it a small agglomeration under the EU Urban Waste Water Treatment Directive (91/271/EEC). The plant is situated inland, away from coastal areas, and its operations are part of the municipal wastewater infrastructure for the region. The plant employs advanced treatment processes, which go beyond the secondary treatment standard required by the EU directive for agglomerations of this size. It has a designed capacity of 5,561.00 m³/day and currently discharges 833.65 m³/day of treated wastewater. The advanced treatment level indicates that the plant likely includes nutrient removal or other tertiary processes to protect sensitive receiving waters. The treated effluent from the Serpa plant is discharged into the local watershed, which ultimately drains into the Guadiana River basin. The Guadiana River flows southward, forming part of the border between Portugal and Spain, and empties into the Gulf of Cadiz in the Atlantic Ocean. The downstream environment supports diverse aquatic life and is an important ecological corridor in the Iberian Peninsula.

The Serpa plant discharges into the Guadiana River basin, a major watercourse in southern Portugal and Spain. The Guadiana River flows through a semi-arid region with seasonal rainfall, and its estuary supports important bird populations and fisheries. The advanced treatment at Serpa helps reduce nutrient loading, protecting downstream water quality in the river and the Gulf of Cadiz.