ALCOLEA DE CALATRAVA Wastewater Treatment Plant, Alcolea de Calatrava, Spain

The ALCOLEA DE CALATRAVA wastewater treatment plant is located in the municipality of Alcolea de Calatrava, in the province of Ciudad Real, within the autonomous community of Castilla-La Mancha, Spain. The plant serves a population of approximately 3,338 residents, making it a small-scale facility in a rural inland setting. The plant employs advanced treatment processes, which go beyond the secondary treatment required by the EU Urban Waste Water Treatment Directive (91/271/EEC) for agglomerations of this size. Advanced treatment typically includes nutrient removal (nitrogen and phosphorus) to protect sensitive receiving waters. The plant discharges a reported volume of 513.00 cubic meters of treated wastewater daily. The treated effluent from the plant is discharged into the local hydrological network, which ultimately drains into the Guadiana River basin. The Guadiana River flows westward through Spain and Portugal before reaching the Gulf of Cádiz in the Atlantic Ocean. The advanced treatment helps protect the ecological health of the Guadiana basin, which supports diverse aquatic life and is important for regional agriculture and biodiversity.

The plant discharges into the Guadiana River basin, one of the major river systems in the Iberian Peninsula. The Guadiana flows through the arid plains of Castilla-La Mancha and Extremadura, supporting irrigated agriculture and wetlands of ecological importance. Downstream, the river forms part of the border between Spain and Portugal before emptying into the Gulf of Cádiz. The advanced treatment at this plant helps reduce nutrient loading, which is critical for preventing eutrophication in the sensitive estuarine and coastal environments of the Guadiana estuary.