ETE Serra Azul Wastewater Treatment Plant, Serra Azul, São Paulo, Brazil

ETE Serra Azul is a wastewater treatment facility located in Serra Azul, within the state of São Paulo, Brazil. The plant serves a population of about 6,714 people, placing it in the small agglomeration category under Brazilian regulatory frameworks. It is situated inland, far from the coast, and operates within the Ribeirão Preto metropolitan region. As a small-scale plant in Brazil, ETE Serra Azul is subject to national environmental standards set by CONAMA (Conselho Nacional do Meio Ambiente) and state-level regulations from CETESB (Companhia Ambiental do Estado de São Paulo). These regulations typically require secondary treatment for municipal wastewater to protect water quality in receiving bodies. Facilities of this size commonly employ biological treatment systems such as activated sludge or stabilization ponds. The treated effluent from ETE Serra Azul is discharged into local watercourses that drain into the Pardo River basin, which flows into the Grande River and eventually reaches the Paraná River basin. This region is part of the Paraná River watershed, one of the most important river systems in South America, supporting agriculture, industry, and biodiversity. The plant plays a key role in protecting downstream water quality and public health.

The treated effluent from ETE Serra Azul enters local streams that feed into the Pardo River, a tributary of the Grande River. The Grande River flows into the Paraná River, which ultimately reaches the Río de la Plata estuary. The watershed supports diverse aquatic life and is used for irrigation and water supply. Protecting water quality in this basin is critical for maintaining ecological balance and human uses downstream.