Abstract

This study critically examines the discrepancies between sludge management practices at water treatment plants (WTPs) and wastewater treatment plants (WWTPs) in São Paulo, Brazil, and the penalties imposed for inadequate management. Using data from the National Survey of Basic Sanitation for 2008 and 2017, alongside a historical series of penalties issued by the São Paulo State Environmental Company from 2000 to 2023, this article uncovers a significant gap between the widespread occurrence of improper sludge disposal and the relatively low frequency of penalties. In 2008 and 2017, 153 and 114 municipalities, respectively, in São Paulo discharged part of their WTP sludge into water bodies, while sixty-one and sixteen municipalities, respectively, did the same with WWTP sludge; yet, penalties remained sparse, averaging just ten for water and four for sewage sludge per year. This study suggests that current command-and-control regulatory approaches are inadequate for driving necessary changes in sludge management. A more collaborative effort among regulators, policymakers, and treatment plant operators is essential to mitigate the environmental impacts of WTPs and WWTPs in São Paulo State.