COLMENAREJO OESTE Wastewater Treatment Plant, Colmenarejo, Spain

COLMENAREJO OESTE is a wastewater treatment plant located in Colmenarejo, a municipality in the Comunidad de Madrid, Spain. The plant serves a population of around 7,793 people, placing it in the small agglomeration category under Spanish and EU regulations. As a plant in Spain, it operates under the EU Urban Waste Water Treatment Directive 91/271/EEC, which requires secondary treatment for agglomerations of this size. The directive also mandates appropriate treatment before discharge into freshwater bodies. It is expected to meet the secondary treatment standards. The plant discharges treated wastewater into the local watershed, which ultimately drains into the Guadarrama River, a tributary of the Tagus River. The Tagus River flows through central Spain and into Portugal, reaching the Atlantic Ocean near Lisbon. The plant plays a key role in protecting the Guadarrama River and downstream ecosystems from pollution.

The plant discharges into the Guadarrama River basin, which flows into the Tagus River, one of the longest rivers in the Iberian Peninsula. The Tagus River supports diverse aquatic life and provides water for agriculture and urban areas. The plant's treatment helps maintain water quality in this ecologically sensitive river system, which is important for migratory fish and other species.