SUESA Wastewater Treatment Plant, Ribamontán al Mar, Cantabria, Spain

SUESA is a wastewater treatment plant located in the municipality of Ribamontán al Mar, in the autonomous community of Cantabria, northern Spain. The plant serves a population of around 21,409 people, placing it in the medium agglomeration category under EU classification. Its location near the Cantabrian coast means that treated effluent ultimately discharges into the Bay of Biscay, part of the Atlantic Ocean. As a Spanish facility, SUESA operates under the national transposition of the EU Urban Waste Water Treatment Directive (91/271/EEC). For agglomerations of this size (between 10,000 and 150,000 population equivalent), the directive requires secondary treatment as a minimum, with more stringent treatment in sensitive areas. The plant's designed capacity is reported as 1.00 (likely in thousands of cubic meters per day or similar unit), indicating a moderate-scale infrastructure. The plant's discharge influences the coastal waters of the Cantabrian Sea, a region known for its rich marine biodiversity and important fisheries. The receiving environment includes estuaries and coastal zones that support diverse aquatic life and are subject to EU Water Framework Directive standards. Proper treatment at SUESA helps protect these sensitive marine ecosystems from nutrient pollution and other contaminants.

SUESA discharges treated wastewater into the Cantabrian Sea, part of the Bay of Biscay in the Atlantic Ocean. The coastal waters off Cantabria support diverse marine habitats, including seagrass meadows and rocky reefs, which are important for fish spawning and migratory species. The region's estuaries also serve as nurseries for commercial fish stocks, making effective nutrient removal critical to prevent eutrophication and maintain water quality.