Los Santos de la Humosa Wastewater Treatment Plant, Comunidad de Madrid, Spain

The Los Santos de la Humosa wastewater treatment plant is located in the Comunidad de Madrid region of Spain, serving the municipality of Los Santos de la Humosa. The plant provides secondary treatment for a population of 2,190, with a designed capacity of 3,000 m³/day and an average discharge volume of 432.93 m³/day. As a secondary treatment facility, the plant meets the minimum requirements of the EU Urban Waste Water Treatment Directive (91/271/EEC) for agglomerations under 10,000 population equivalent. The directive mandates secondary treatment for all discharges from agglomerations of this scale, ensuring organic matter and suspended solids are adequately reduced before discharge. The plant's treated effluent is discharged into the local watershed, which ultimately drains into the Henares River, a tributary of the Jarama River, and then into the Tagus River basin. The Tagus River flows through central Spain and into Portugal, discharging into the Atlantic Ocean near Lisbon. The plant plays a key role in protecting the Henares River and downstream ecosystems from pollution.

The plant discharges into the Henares River basin, which flows into the Jarama River and then the Tagus River, one of the longest rivers in the Iberian Peninsula. The Tagus River supports diverse aquatic life and is an important water resource for agriculture and urban areas. The plant's secondary treatment helps reduce organic pollution and nutrient loads, protecting downstream water quality and ecological health in the Tagus basin.