The São Sebastião city hall has levied a fine of R$100,000 against Sabesp, the basic sanitation company of São Paulo, due to environmental infractions related to the contamination of the Maresias river. The local government accuses Sabesp of excessively dosing hypochlorite at its wastewater treatment station, which has led to significant ecological harm. This decision was made by the Municipal Secretary of the Environment following an environmental inspection prompted by a received complaint.

On February 26, city officials conducted an inspection at the river's mouth after reports of fish deaths, observing a substantial number of dead fish, including native species like acarás papa-terra and catfish. Investigators noted a strong chlorine odor at the riverbanks and near a passage box where the fish were found. The inspections revealed a broken register in one of the hypochlorite storage tanks, suggesting poor management and oversight in the treatment process.

This incident raises concerns about the operational practices of Sabesp, a vital utility in São Paulo, especially as environmental violations indicate a potential threat to local biodiversity and marine life. The fines imposed serve as a reminder of the importance of regulatory compliance in waste management and the protection of aquatic ecosystems. As the case develops, it may influence future policies regarding environmental protection and corporate responsibility among sanitation providers in Brazil.