ETE Santo Antônio da Alegria - Secondary Wastewater Treatment Plant in São Paulo, Brazil

ETE Santo Antônio da Alegria is a municipal wastewater treatment plant located in Santo Antônio da Alegria, in the state of São Paulo, Brazil. The plant serves a population of approximately 4,507 residents, making it a small-scale facility within the region's sanitation infrastructure. It is situated inland, far from the coast, and operates under Brazil's national environmental regulations. The plant provides secondary treatment, which is the standard level required for urban wastewater in Brazil under CONAMA Resolution 430/2011 and other federal norms. Secondary treatment typically involves biological processes to reduce organic matter and suspended solids. For a facility of this size, secondary treatment is appropriate and aligns with regulatory expectations for small agglomerations. The treated effluent is discharged into local water bodies, likely tributaries of the Rio Pardo or Rio Grande, which are part of the Paraná River basin. This basin drains into the Río de la Plata estuary in Argentina and Uruguay. The plant plays a key role in protecting downstream water quality, particularly in a region dominated by agriculture and small urban centers. Proper treatment helps prevent eutrophication and safeguards aquatic ecosystems in the broader Paraná watershed.

The plant discharges into local streams that feed into the Rio Pardo, a tributary of the Rio Grande, which flows into the Paraná River basin. This basin is one of South America's largest, draining into the Río de la Plata estuary. The region supports diverse aquatic life and is important for agriculture and water supply. Effective wastewater treatment is critical to prevent nutrient pollution and maintain ecological balance in this extensive watershed.