ETE Pedra de Guaratiba - Wastewater Treatment Plant in Rio de Janeiro, Brazil

ETE Pedra de Guaratiba is a wastewater treatment plant located in the Guaratiba neighborhood of Rio de Janeiro, Brazil. It serves a population of approximately 11,468 residents, placing it in the small-to-medium agglomeration category. The plant is situated in the western zone of the city, near the Piraquê River. Brazil's wastewater treatment facilities are regulated under the National Environmental Council (CONAMA) resolutions and the National Water Resources Policy. For plants of this scale, secondary treatment is typically required to meet effluent standards. The plant discharges into the Piraquê River, which flows into the Sepetiba Bay, an important coastal ecosystem in Rio de Janeiro state. Sepetiba Bay supports diverse marine life and is a key area for fishing and biodiversity. The plant's location within 50 km of the coast means its effluent can impact coastal water quality, making proper treatment essential for protecting the bay's ecological health.

The plant's treated effluent enters the Piraquê River, which drains into Sepetiba Bay, a semi-enclosed coastal lagoon system on the Atlantic coast of Brazil. Sepetiba Bay is an ecologically sensitive area that supports mangrove forests, seagrass beds, and diverse fish and crustacean populations. The bay also serves as a nursery for commercially important species. Protecting water quality in this watershed is critical for maintaining the bay's productivity and the livelihoods of local fishing communities.