Villasana de Mena Wastewater Treatment Plant, Valle de Mena, Burgos, Spain

Villasana de Mena is a wastewater treatment plant located in the municipality of Valle de Mena, in the province of Burgos, Castilla y León, Spain. The plant serves a population of 3,596 and is situated inland, more than 10 km from the coast. It provides secondary treatment, which is the standard level for small agglomerations under Spanish and European regulations. As a secondary treatment facility, Villasana de Mena removes organic matter and suspended solids through biological processes. The plant has a designed capacity of 3,596 population equivalents, matching the population served, and discharges an average volume of 636.99 cubic meters per day. Under the EU Urban Waste Water Treatment Directive (91/271/EEC), agglomerations of this size are required to have secondary treatment, which this plant fulfills. The treated effluent is discharged into local watercourses that eventually drain into the Mediterranean Sea via the Ebro River basin. The plant plays a key role in protecting the local watershed and downstream aquatic ecosystems from pollution. Its operation helps maintain water quality in the region, supporting biodiversity and human uses of water resources.

The plant discharges into the local river system within the Ebro River basin, which flows into the Mediterranean Sea. The Ebro basin supports diverse aquatic life and is an important ecological corridor in northern Spain. The secondary treatment provided by the plant helps reduce nutrient and organic pollution, protecting downstream water quality and the sensitive coastal environment of the Mediterranean.