Viso del Marqués Wastewater Treatment Plant, Castilla-La Mancha, Spain

The Viso del Marqués wastewater treatment plant is located in the municipality of Viso del Marqués, in the province of Ciudad Real, within the autonomous community of Castilla-La Mancha, Spain. The plant serves a population of approximately 5,016 people, making it a small-scale facility in a rural inland setting. The plant employs advanced treatment processes, which go beyond the secondary treatment required by the EU Urban Waste Water Treatment Directive (91/271/EEC) for agglomerations of this size. This level of treatment ensures high-quality effluent, reducing nutrient loads and protecting receiving waters. The plant's discharge volume is reported at 892 cubic meters per day. The treated effluent is discharged into local watercourses that ultimately drain into the Guadiana River basin, one of Spain's major river systems. This basin supports diverse aquatic life and agricultural activities downstream. The advanced treatment helps safeguard water quality in this semi-arid region, where water resources are particularly valuable.

The plant discharges into the Guadiana River basin, which flows through central Spain and eventually reaches the Atlantic Ocean via the Gulf of Cadiz. The region's semi-arid climate makes water quality management critical for sustaining local ecosystems and agricultural irrigation. The advanced treatment reduces nutrient pollution, protecting downstream habitats and supporting biodiversity in the river system.