Nearly half of South Africa’s municipal wastewater treatment systems are in a critical state of performance, according to the department of water and sanitation’s latest Green Drop assessment, and the machinery meant to turn that around is showing the strain. Of the 848 municipal wastewater systems assessed during the 2023/24 financial year, 396 were classified as critical, up from 334, or 39%, in the 2022 report. The proportion performing at good or excellent levels fell from 14% to 8%.