DODRO Wastewater Treatment Plant, O Sar, Galicia | Advanced Treatment, Coastal Discharge

DODRO is a wastewater treatment plant located in O Sar, within the municipality of Dodro, in the province of A Coruña, Galicia, Spain. It serves a population of 1,330 and is situated near the AC-305 road. The plant is currently closed, but its infrastructure remains part of the region's wastewater management history. The plant was designed with an advanced treatment level, indicating it employed processes beyond secondary treatment to remove nutrients and other pollutants. Its designed capacity was 4,500 m³/day, though the actual discharge volume recorded is 241.06 m³/day. Under the EU Urban Waste Water Treatment Directive (91/271/EEC), plants serving agglomerations of this size are typically required to provide secondary treatment, but advanced treatment may be mandated in sensitive areas. The plant is located within 10 km of the coast, meaning its treated effluent likely discharges into a river or estuary that flows into the Atlantic Ocean along the Galician coast. This coastal proximity underscores the importance of effective treatment to protect marine ecosystems and comply with EU directives for sensitive areas.

The plant is situated in the Ulla River basin, which drains into the Ría de Arousa, a coastal inlet of the Atlantic Ocean in Galicia. This estuary supports diverse aquatic life, including shellfish beds and migratory fish species. The advanced treatment level helps minimize nutrient loading and protect the sensitive coastal environment from eutrophication.