DUENAS Wastewater Treatment Plant, Dueñas, Castilla y León, Spain

The DUENAS wastewater treatment plant is located in Dueñas, a municipality in the province of Palencia, within the autonomous community of Castilla y León, Spain. The plant serves a population of approximately 5,700 residents, providing secondary treatment to municipal wastewater. Its designed capacity is 5,700 volume units, matching the population served, and it discharges a daily volume of 602.74 units. As a secondary treatment facility, the plant meets the standard requirements under the European Union's Urban Waste Water Treatment Directive (91/271/EEC), which mandates secondary treatment for agglomerations of this size. The directive aims to protect the environment from the adverse effects of untreated wastewater, particularly in sensitive areas. The treated effluent from the plant is discharged into the local watershed, which ultimately drains into the Duero River basin. The Duero River flows westward through Spain and into Portugal, emptying into the Atlantic Ocean at Porto. The plant plays a key role in maintaining water quality in this important river system, supporting aquatic life and downstream ecosystems.

The DUENAS plant discharges into the Duero River basin, a major watershed in northern Spain that flows into the Atlantic Ocean. The Duero River supports diverse aquatic habitats and is an important resource for agriculture and drinking water. The plant's secondary treatment helps reduce organic pollutants and nutrients, protecting downstream water quality and ecological balance.