Dirty, sickening water spreads disease in three counties.

Residents in Nairobi, Machakos and Kajiado counties are consuming or may have been exposed to contaminated water, leading to an unprecedented increase in cases of diarrhoea and water-borne diseases, including cholera, exclusive tests by the Star have established.

The state of the city's water supply was brought into sharp focus when tenants of four buildings in the Nairobi CBD, namely I and M Building, Pioneer House, Rehani House and Post Bank Building, started complaining of foul-smelling water from their taps.

TESTING PROCESS

The Star collected four water samples, one each from I and M, Pioneer, Rehani and Post Bank buildings. For sampling, we picked sterilised bottles from the Kenya National Public Health Laboratory as required, and got the water direct from taps in the four buildings.

To avoid contamination, we returned the samples in less than 30 minutes after collection. The samples were then subjected to bacteriological analysis at the Public Health Laboratory at Kenyatta National Hospital.

According to the lab analysis, the water samples from three buildings had high levels of Escherichia coli (E. coli) and other coliform bacteria, which are characteristic of water contaminated with faecal matter, raising fears of a potential cholera outbreak, which Nairobi county confirmed last Friday afternoon.

Out of the four samples, only one sample, that of I and M building, which serves as the headquarters of I and M bank and houses the Standard Media Group's Nairobi bureau, scored the class 1 mark, meaning that it is 'highly satisfactory' for human consumption, having no signs of coliforms or E. coli for each 100ml sample tested from the location.

The other three samples got the class IV mark, indicating the water was highly unsatisfactory for human consumption, unless further treatment was done.

Water samples collected from Rehani House, which serves as the headquarters of the Housing Finance Corporation, had 35 coliforms and two E. coli in the 100ml sample collected. Post Bank building had a shocking 180 coliforms and 14 E. coli in 100ml of water collected, while water samples collected from Pioneer building, sandwiched between Tuskys Supermarket and I and M building on Kenyatta Avenue, had 25 coliforms and zero E. coli in 100ml of treated water, making it unsatisfactory for human consumption.

The four buildings share the same water distribution system connected by a valve at Rehani House, where the contamination is said to have first occurred.

Nairobi City Water and Sewerage Company (NCWSC) had earlier refuted claims that the water in the four buildings in question was contaminated. However, employees in the four buildings were warned in February 2019 to not drink or use the tap water, which had a foul smell.

According to the lab analysis, the water contains a high number of Coliforms and E. coli bacteria, which indicate that it may have been contaminated with sewage.

A memo addressed to I and M staff implored workers to avoid using tap water, adding that the issue was being resolved by the NCWSC.

'...Pass the information to your workmates that the condition of tap water in the building is suspicious and the matter has been reported to Nairobi Water, who are handling it. The water should be used for flushing toilets only,' read an internal memo by Peter Mwania Nzuki at the I and M building.

WATER 'TREATED'

However, NCWSC corporate affairs manager Mbaruku Vyakweli insisted that the water supplied to the buildings had been treated, and, therefore, did not have any contaminants. He also denied reports that the contamination could have occurred from another line.

'We are not aware and no issue has been reported to us,' Vyakweli said, adding that NCWSC has a strong quality assurance team that does random sampling of the water from the CBD on a daily basis.

Vyakweli said the only area in Nairobi Water's distribution network that has had issues of contamination is Umoja area in Eastlands, but the issue has since been resolved.

'So far, we have not had any cause for alarm,' Vyakweli said. 'Recently we had an issue at Koinange Street and it was repaired, so maybe the samples are not from our main supply because we take issues of contamination very seriously.'

By the time we were investigating this matter, officers from Nairobi water had opened up the distribution valve to identify the location of a blockage that had restricted water supply to the four buildings but left it open, and this could be the point at which the contamination happened.

Dr Kepha Ombacho, director of Public Health at the Health ministry, said the ministry was yet to receive any formal complaints about contaminated water.

Ombacho said the matter is a devolved function and thus City Hall was best placed to respond to the situation.

'If they have raised concerns and no assistance has been availed, they should come to the ministry and seek help,' Ombacho said.

Asked to explain what the results we had obtained at the...