ETE PIAU Wastewater Treatment Plant - Região Metropolitana de São José do Rio Preto, São Paulo, Brazil

ETE PIAU is a wastewater treatment plant located in the Região Metropolitana de São José do Rio Preto, within the state of São Paulo, Brazil. It serves a population of about 9,172 people, placing it in the small agglomeration category under Brazilian wastewater regulations. In Brazil, wastewater treatment plants are regulated by the National Environmental Council (CONAMA) and state environmental agencies, which set discharge standards based on the receiving water body classification. For small agglomerations, secondary treatment is typically required to meet these standards. The treated effluent from ETE PIAU is discharged into local water bodies that drain into the Paraná River basin, one of the most important river systems in South America. The Paraná River flows through Brazil, Paraguay, and Argentina before emptying into the Río de la Plata estuary. The plant's operations help protect downstream aquatic ecosystems and water quality in this major drainage basin.

The plant's discharge enters local streams that are part of the Paraná River basin, which drains into the Río de la Plata estuary. This watershed supports diverse aquatic life and is an important resource for agriculture, industry, and drinking water. Protecting water quality in this basin is critical for maintaining ecological balance and human health in the region.