Villarramiel Wastewater Treatment Plant, Palencia, Castilla y León

The Villarramiel wastewater treatment plant is located in the municipality of Villarramiel, in the province of Palencia, within the autonomous community of Castilla y León, Spain. The plant serves a population of approximately 8,141 people and operates with secondary treatment, which is the standard biological treatment required under the EU Urban Waste Water Treatment Directive (91/271/EEC) for agglomerations of this size. As a secondary treatment facility, the plant removes organic matter and suspended solids through biological processes, meeting the directive's requirements for inland discharges. The plant's designed capacity is 8,141 population equivalents, and it discharges a daily volume of 400 cubic meters of treated wastewater. The treated effluent is discharged into a local watercourse that ultimately drains into the Duero River basin, one of the major river systems in the Iberian Peninsula. The Duero River flows westward through Spain and Portugal, emptying into the Atlantic Ocean at Porto. The plant plays a key role in protecting the local aquatic environment and downstream water quality in the Duero basin.

The plant discharges into a tributary of the Duero River basin, which drains a large agricultural region in northern Spain. The Duero River supports diverse aquatic life and is an important water resource for irrigation and drinking water. Downstream, the river forms the border between Spain and Portugal before reaching the Atlantic Ocean. The secondary treatment provided helps reduce organic pollution and protect the ecological health of the receiving waters.