Assessment of microbial water quality and health risk associated with the presence of Escherichia coli in water from selected villages in the Eastern Cape, South Africa

Abstract

Evaluation of groundwater and surface water quality is critical for their sustainable utilisation for various purposes. In this study, surface water and groundwater samples were collected during dry and wet seasons of 2023 from boreholes, springs, and streams in 19 selected villages across four local municipalities in the Eastern Cape Province, South Africa. Microbiological contamination was investigated, and the results showed that 62.7% of the samples had high total coliform counts, while 37.3% had low total coliform counts. Furthermore, the results showed that 18.5% of the water samples were contaminated with Escherichia coli . Quantitative microbial risk assessment results showed that the high-risk daily and annual infection probabilities ranged from 0 .31 to 0.51 and 0.42 to 0.67 for adults and children, respectively. In addition, the probability of illness associated with Escherichia coli -contaminated water was 0.35 across 18 of the 37 water sources assessed. These findings indicate elevated microbial contamination in both groundwater and surface water sources posing potential health risks to communities that rely on untreated water. Therefore, improved rural water quality management, regular monitoring programmes, and appropriate water treatment interventions are recommended to protect public health and ensure the sustainable use of these water resources.