Assessment of Bacteriological Quality and Physicochemical Properties of Borehole Water Supplies in Eastleigh, Nairobi County, Kenya

Abstract

BACKGROUND A borehole is a valuable source of fresh, potable water that globally feeds around 1.5 billion people daily. It is, however, vulnerable to both microbial and chemical pollution, which poses health risks to the population if consumed without proper treatment. It is from this perspective that this study aimed to assess the quality of borehole water supplies in Eastleigh, considering their implications for human health.

METHODOLOGY A repeated cross-sectional design was employed to study physicochemical and microbiological parameters of the boreholes. A proportionate stratified sampling method was used to sample 25 boreholes. Water samples from the storage tanks of the boreholes were collected in sterilised 250 ml glass bottles and transported to Kenyatta University microbiology laboratories for analysis. Temperature, pH, Turbidity and Fluoride levels were measured by their respective meters. Lead, cadmium and Arsenic levels were determined by the Atomic Absorption Spectrophotometer. The Most Probable Number technique quantified the coliform and Microbial culturing for bacterial detection. A 12-month retrospective case-control design determined the prevalence of waterborne illnesses from the Eastleigh Community Wellness Centre, Eastleigh Health Centre and Biafra Health Facility hospitals. Mean values obtained for physicochemical and microbiological parameters during the wet and dry seasons (April-May, 2024 and July, 2024, respectively) and across the road streets were analysed using one-way analysis of variance, with p ≤0.05 being significant.

RESULTS All physicochemical parameters were generally within Kenya Bureau of Standards (KEBS) permissible standards for drinking water, except for cadmium, fluoride and pH. The total coliform exceeded the KEBS permissible requirements. At least one of the pathogenic bacteria of interest (Escherichia coli, Vibrio cholerae, Salmonella spp and Shigella spp) was detected in every borehole. Review of the patient’s clinical data showed an overall prevalence rate of 8.5%, with patients <5 years and >5 years recording 11.06% and 7.33%, respectively.

CONCLUSION Borehole water in Eastleigh is contaminated, and with the prevalence rate of 8.5%, it concludes waterborne diseases in the region as a public health concern. Consumption of water from questionable sources like these boreholes should be limited.