Campillo y Retamal de la Llerena Wastewater Treatment Plant, Campillo de Llerena, Extremadura

The Campillo y Retamal de la Llerena wastewater treatment plant is located in Campillo de Llerena, a municipality in the province of Badajoz, Extremadura, Spain. The plant serves a population of approximately 3,200 people, reflecting its role in managing domestic wastewater for this small inland community. The plant operates with secondary treatment, which is the standard biological treatment stage required under the EU Urban Waste Water Treatment Directive (91/271/EEC) for agglomerations of this size. The designed capacity of 8,000 m³/day indicates the plant is sized to handle peak flows, while the reported discharge volume of 579.99 m³/day suggests current utilization is well below capacity. The treated effluent is discharged into the local hydrological network, ultimately draining into the Guadiana River basin, which flows westward into the Atlantic Ocean. The plant's operation helps protect local water quality and supports the ecological health of the Guadiana catchment, an important agricultural and ecological region in southwestern Spain.

The plant discharges into a tributary of the Guadiana River, one of the major rivers of the Iberian Peninsula, which flows into the Gulf of Cádiz (Atlantic Ocean). The Guadiana basin supports diverse aquatic life and is a critical water resource for agriculture in Extremadura. The secondary treatment provided by the plant reduces organic pollutants and nutrients, helping to prevent eutrophication in downstream water bodies and maintaining the ecological balance of the river system.