ETE Sarapuí Wastewater Treatment Plant, Belford Roxo, Rio de Janeiro, Brazil

ETE Sarapuí is a major wastewater treatment facility located in Belford Roxo, within the Rio de Janeiro metropolitan area, Brazil. The plant serves a population of approximately 295,363, placing it in the large agglomeration category for regulatory purposes. As a large-scale plant in Brazil, ETE Sarapuí is subject to the National Environmental Council (CONAMA) resolutions and state-level environmental permits, which typically require secondary treatment or higher for such population sizes. The plant's designed capacity is reported as 1.00 (likely in cubic meters per second or similar unit), indicating substantial infrastructure to handle the region's wastewater. The plant discharges treated effluent into local water bodies that ultimately drain into Guanabara Bay, a large coastal bay in southeastern Brazil. This bay is ecologically significant, supporting diverse aquatic life and serving as a critical habitat for fish and crustaceans. The plant plays a key role in reducing pollution loads to the bay, which faces pressures from urbanization and industrial activities in the Rio de Janeiro region.

ETE Sarapuí discharges into the Sarapuí River, a tributary of Guanabara Bay. Guanabara Bay is a large, semi-enclosed estuary that drains into the Atlantic Ocean. The bay supports diverse aquatic life, including mangroves and fish species, and is an important ecological and economic resource for the region. The plant's operations help mitigate nutrient and pathogen inputs, protecting downstream water quality and ecosystem health.