Santa Eulalia de Roncana Wastewater Treatment Plant, Lliçà d'Amunt, Catalunya

Santa Eulalia de Roncana is a wastewater treatment plant located in Lliçà d'Amunt, in the province of Barcelona, Catalunya, Spain. The facility serves a population of approximately 7,440 people and has a designed capacity of 1.00 volume units, reflecting its role in managing municipal wastewater for this small agglomeration. 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 more advanced treatment if the receiving waters are designated as sensitive areas. It is expected to comply with national and EU standards. The treated effluent is discharged into local watercourses that eventually drain into the Mediterranean Sea. The plant plays a key role in protecting the regional watershed, which supports diverse aquatic life and contributes to the ecological health of the coastal environment. Its operation helps prevent nutrient pollution and maintains water quality in the downstream river systems.

The plant discharges into local streams that flow into the Besòs River basin, which ultimately reaches the Mediterranean Sea near Barcelona. This coastal region supports important marine habitats and is subject to EU regulations for sensitive areas. The treatment plant helps reduce nutrient loads and organic pollutants, safeguarding the ecological balance of the river and coastal waters.