Velilla del Río Carrión Wastewater Treatment Plant | Advanced Treatment in Palencia, Spain

The Velilla del Río Carrión wastewater treatment plant is located in the municipality of Velilla del Río Carrión, in the province of Palencia, within the autonomous community of Castilla y León, Spain. The facility serves a population of approximately 2,500 residents, classifying it as a small agglomeration under Spanish and EU regulations. The plant employs advanced treatment processes, which go beyond the secondary treatment standard required by the EU Urban Waste Water Treatment Directive (91/271/EEC) for agglomerations of this size. With a designed capacity of 2,500 m³/day and an actual discharge volume of 691.20 m³/day, the plant operates well within its capacity, indicating efficient management. The treated effluent is discharged into the local watershed, which ultimately drains into the Carrión River, a tributary of the Pisuerga River, part of the Duero River basin. The Duero River flows westward through Spain and into Portugal, emptying into the Atlantic Ocean near Porto. The advanced treatment helps protect the ecological quality of the Carrión River and downstream water bodies, supporting aquatic life and water quality standards.

The plant discharges into the Carrión River, a tributary of the Pisuerga River, which is part of the larger Duero River basin. The Duero River flows through Spain and Portugal to the Atlantic Ocean. The watershed supports diverse aquatic ecosystems, including fish species such as trout and barbel, and the advanced treatment helps maintain water quality for downstream communities and habitats.