GUADALIX Wastewater Treatment Plant, Guadalix de la Sierra, Spain

GUADALIX is a wastewater treatment plant located in Guadalix de la Sierra, a municipality in the Comunidad de Madrid region of Spain. The plant serves a population of approximately 3,525 residents, classifying it as a small agglomeration under European Union regulations. As a Spanish facility, GUADALIX operates within the framework of 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 inland waters, ensuring compliance with environmental standards. The plant's treated effluent is discharged into local watercourses that eventually drain into the Tagus River basin, a major Iberian watershed. The Tagus River flows westward through Spain and Portugal, emptying into the Atlantic Ocean near Lisbon. The plant plays a role in protecting the ecological health of these downstream waters.

The plant discharges into local streams that are part of the Tagus River basin, one of the longest rivers in the Iberian Peninsula. The Tagus flows through diverse ecosystems, including agricultural and urban areas, before reaching the Atlantic Ocean. The receiving waters support aquatic life and are used for irrigation and recreation downstream. Protecting water quality in this basin is important for regional biodiversity and human use.