The deaths occurred in the city’s Mukuru Kwa Njenga slum.
While selling water is a tightly-regulated business in the city, with vendors required to apply for permits from the Nairobi City Water and Sewerage Company (NCWSC), many sidestep the rules as there is a market for cheaper, untested water.
It is a large-scale business with dealers selling water by the tanker-load rather than a few bottles here and there.
The water sold by the vendors comes from boreholes in the city that are regularly tested and known not to carry cholera, leading the slum-dwellers and officials alike to seek and explanation of where infection is coming from.
Officials are blaming operators who use their tankers to collect sewage on week and sell water from them the next.
Sam Bond