ETE IRAPe Wastewater Treatment Plant, Chavantes, São Paulo

ETE IRAPe is a wastewater treatment plant located in the Irapé district of Chavantes, in the state of São Paulo, Brazil. The plant serves a population of approximately 11,246 residents, placing it in the small-to-medium agglomeration category for Brazilian wastewater infrastructure. Its location in the interior of São Paulo state places it within a region of mixed agricultural and urban land use. Brazil's wastewater treatment framework is governed by CONAMA Resolution 430/2011 and the National Water Resources Policy (Law 9.433/1997), which set discharge standards for treated effluent. For plants of this scale, secondary treatment is typically required to meet biochemical oxygen demand and suspended solids limits. Regulatory compliance is overseen by state environmental agencies such as CETESB in São Paulo. The treated effluent from ETE IRAPe likely discharges into a local watercourse within the Paraná River basin, which ultimately flows into the Río de la Plata estuary. The downstream environment supports diverse aquatic life and is important for regional water supply and irrigation. Proper treatment helps protect water quality in this ecologically sensitive basin.

The plant discharges into a tributary of the Paranapanema River, part of the larger Paraná River basin. This basin drains into the Río de la Plata estuary, supporting diverse aquatic ecosystems and providing water for agriculture and human consumption. The region's watershed is ecologically sensitive, with seasonal rainfall patterns influencing flow and pollutant dilution.