Microbial quality of domestic water: following the contamination chain in a rural township in Kenya

A study was undertaken in Njoro Township, Kenya to evaluate the extent to which drinking water was subjected to post-collection faecal contamination in low-income and high-income households. Boreholes were the main drinking water sources, accounting for roughly 70% singular access. The microbial quality of drinking water from the boreholes deteriorated from the point-of-collection through conveying containers of small-scale water vendors to household storage containers, irrespective of their income status. The densities of Escherichia coli (EC) were relatively low at the point-of-collection – median (M): 18 CFU/100 mL, range (R): 0–220, n = 60 – increasing considerably in the containers of water vendors (M: 290 CFU/100 mL, R: 30–350) and slightly (M: 360 CFU/100 mL, R: 0–520) between vendors and low-income households, many of whom used the services of vendors unlike high-income households who relied on a piped system on premises (M: 40 CFU/100 mL, R: 0–500). Post-collection contamination was high in low-income households compared to high-income households but differences were not significant between the two household categories with and without household water treatment (HWT). Different HWT methods in the two household categories significantly reduced faecal contamination, but unhygienic handling and poor storage practices afterwards caused recontamination. HWT and behavioural change measures need not selectively target household groups solely on the basis of their income status.