ETE Cachoeira Paulista Wastewater Treatment Plant, Cachoeira Paulista, São Paulo

ETE Cachoeira Paulista is a wastewater treatment plant located in the Pitéu district of Cachoeira Paulista, within the Vale do Paraíba region of São Paulo state, Brazil. The plant serves a population of approximately 24,170, classifying it as a medium-sized agglomeration under Brazilian sanitation standards. Brazil's wastewater treatment facilities are regulated by the National Environmental Council (CONAMA) and the National Water Agency (ANA), with discharge standards set by CONAMA Resolution 430/2011. For plants of this scale, secondary treatment is typically required to reduce organic load and suspended solids before discharge into receiving water bodies. The plant's treated effluent likely discharges into a tributary of the Paraíba do Sul River, a major watercourse that flows through the states of São Paulo, Rio de Janeiro, and Minas Gerais. The Paraíba do Sul River is critical for water supply, agriculture, and industry, and supports diverse aquatic ecosystems in the Atlantic Forest biome.

The plant is situated in the Paraíba do Sul River basin, which drains into the Atlantic Ocean near Campos dos Goytacazes, Rio de Janeiro. The river supports important fish populations and provides water for millions of people. The surrounding Atlantic Forest region is ecologically sensitive, with high biodiversity and numerous endemic species. Proper treatment is essential to prevent nutrient pollution and protect downstream water quality.