A decade of faecal pollution: Assessing faecal pollution trends in major South African Rivers

Abstract

Rivers represent crucial natural assets that sustain diverse socio-economic activities and ecosystems. However, these invaluable resources face imminent threats stemming from faecal contamination, which not only affects environmental integrity but also poses significant risks to public health. In South Africa, major rivers are grappling with escalating pollution levels and deteriorating water quality, primarily attributable to deficiencies in sanitation infrastructure, rapid population expansion, urbanization trends, and the inadequate treatment of municipal, industrial, and agricultural waste. This predicament is particularly alarming given the country's prevailing water scarcity and semi-arid climatic conditions. The present study constitutes a comprehensive examination aimed at critically assessing the microbial water quality status of eight prominent South African rivers spanning a decade-long timeframe from 2010 to 2019. These rivers encompass the Limpopo River, Olifants River, Inkomati River, Mzimvubu River, Breede River, Berg-Olifants River, Phongolo River, and Vaal River. Data utilized in this study were sourced from secondary repositories such as the National Microbial Monitoring Programme (NMMP) administered by the Department of Water and Sanitation (DWS). Rigorous statistical analyses were employed to elucidate temporal and seasonal variations in faecal contamination trends, alongside determining statistically significant mean concentrations of Escherichia coli (E. coli). The outcomes of this investigation revealed pervasive faecal contamination across major South African rivers, with discernible escalations in E. coli levels recorded across multiple years. Furthermore, the analysis unveiled seasonal fluctuations in contamination levels, coinciding notably with precipitation patterns and land utilization practices.