ILLANA Wastewater Treatment Plant, Illana, Castilla-La Mancha, Spain

The ILLANA wastewater treatment plant is located in Illana, a municipality in the province of Guadalajara, Castilla-La Mancha, Spain. It serves a population of approximately 1,152 residents, making it a small-scale facility within the region's wastewater infrastructure. As a secondary treatment plant, ILLANA employs biological processes to reduce organic matter and suspended solids. Under the EU Urban Waste Water Treatment Directive 91/271/EEC, agglomerations with a population equivalent (PE) between 2,000 and 10,000 are typically required to have secondary treatment. While ILLANA's population served is below 2,000, the plant's secondary treatment level aligns with the directive's standards for protecting receiving water bodies. The treated effluent is discharged into local watercourses that drain into the Tagus River basin, which flows westward through central Spain and eventually into the Atlantic Ocean near Lisbon. The plant plays a key role in protecting the local watershed from untreated sewage, supporting aquatic life and downstream water quality.

The ILLANA plant discharges into the Tagus River basin, one of the Iberian Peninsula's major river systems. The Tagus River flows through central Spain and Portugal, supporting diverse aquatic ecosystems and providing water for agriculture and human consumption. The plant's secondary treatment helps reduce nutrient loads and organic pollution, protecting downstream habitats and the ecologically sensitive Tagus estuary.