A São Paulo court ordered an immediate halt to untreated sewage discharges into waterways in the municipality of Tietê. The injunction, issued on 10 August, requires the city government and the Autonomous Municipal Water and Sewage Service, Samae, to prevent releases from treatment plants, pumping stations and other parts of the network.
The order follows a public civil action by the Tietê/Sorocaba Regional Environmental Prosecutor's Office. The case contains inspections, violation notices, technical reports and an expert assessment from the Public Prosecutor's support centre. Cetesb and regulator Ares-PCJ had identified recurring irregularities in the municipal system.
Inspectors recorded untreated discharges, effluent outside legal standards, overflows and structural deficiencies in treatment and pumping facilities. Tietê has a high sewage-collection rate, yet prosecutors described actual treatment efficiency as practically nonexistent because of operational problems at the units.
Prosecutors argue that this was neither an isolated accident nor pollution caused by a single private operator. The case concerns persistent failures in public infrastructure. That diagnosis broadens the duty: plugging one outlet is insufficient; capacity, maintenance and compliance must be restored across the sanitation chain.
The injunction demands emergency operation and maintenance measures, especially at the Central, Bertola, Terra Nova and Bonanza treatment plants. It also covers pumping stations with a history of overflows. The first test is whether discharges actually stop during repairs without merely shifting the problem elsewhere in the basin.
The municipality and Samae have 60 days from the ruling to submit an integrated regularization and capacity-restoration plan. It must identify works, maintenance, schedules and compliance with technical and environmental standards. As an interim decision, litigation continues; the city said it would respond after updating its information.
The court also ordered permanent laboratory monitoring of effluent and receiving waters. Results must be sent to the court and published monthly on municipal and Samae websites until at least 3 August 2027. That transparency enables assessment based on water quality, operational continuity and verifiable compliance, not only promises or construction.
