ORELLANA LA VIEJA Wastewater Treatment Plant, Orellana la Vieja, Extremadura, Spain

ORELLANA LA VIEJA is a wastewater treatment plant located in Orellana la Vieja, a town in the province of Badajoz, Extremadura, Spain. The plant serves a population equivalent of 8,100, classifying it as a small agglomeration under EU regulations. As a Spanish facility, the plant operates under the national transposition of the EU Urban Waste Water Treatment Directive (91/271/EEC). For agglomerations between 2,000 and 10,000 population equivalent, the directive requires appropriate treatment, typically secondary treatment, unless the receiving waters are designated as sensitive areas requiring more stringent treatment. The plant's treated effluent is discharged into the local watershed, which ultimately drains into the Guadiana River basin. The Guadiana River flows westward through Extremadura and into the Gulf of Cádiz (Atlantic Ocean), supporting diverse aquatic ecosystems and agricultural irrigation along its course.

The plant discharges into the Guadiana River basin, a major Iberian watercourse that flows through Extremadura and into the Atlantic Ocean via the Gulf of Cádiz. The Guadiana supports important aquatic habitats and is used for irrigation and drinking water supply. Downstream areas include the Guadiana Estuary, which provides nursery grounds for fish and migratory bird habitats.