Dirty, sickening water spreads disease in three counties

Foul-smelling tap water has bacteria found in faecal matter, the Star has established

In Summary

• Exclusive lab tests by the Star have established high levels of bacteria.

• This has raised fears of a cholera outbreak, which Nairobi county confirmed last Friday.

Pupils from Moi Avenue Primary School fetching water.
Pupils from Moi Avenue Primary School fetching water.

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&M Building, Pioneer House, Rehani House and Post Bank Building, started complaining of foul-smelling water from their taps.  


The Star collected four water samples, one each from I&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&M building, which serves as the headquarters of I&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&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&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&M building.


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 Public Health Laboratory meant, Ombacho said the water contains either human or animal waste.

“Safe water for human consumption is supposed to contain zero coliforms and E. coli. When it is said to be with either, then automatically the water is bad,” he said.

“Contrary to what many Kenyans believe,” he added, “diarrhoea is dangerous and when left untreated, it can kill. When people start to diarrhoea, then that is a serious case that needs urgency. However, we have not received any information so far.”

Even after a spot check by local media last month revealed the building managers in these four buildings were aware of the lurking danger, Vyakweli last Tuesday told the Star the company had not received any reports of water contamination.

The Star went undercover to establish whether the matter had been settled. It was found that the contaminated water flowing from the taps had been caused by a sewage leak in the main water supply line, causing contaminated water to mix with clean water coming into the buildings.

Some of the guards use the water to wash cars, and they reported that the water had a strong smell like that of sewage that was not there before
James Chege, Rehani House caretaker 

Rehani House caretaker James Chege said the problem had been detected on February 14, and it was reported to Nairobi Water on February 21.

“Some of the guards use the water to wash cars, and they reported that the water had a strong smell like that of sewage that was not there before,” James said.

“For the entire week, we ignored the smell, thinking it was just the usual dirt in the pipes that makes the water produce a funny smell whenever it is about to run out, meaning the tanks would need to be cleaned. However, by Friday, February 22, the smell was too strong to ignore, and that is when we knew something was wrong.

“We are the ones who raised the alarm. Imagine how God loves us. We were drinking contaminated water but luckily no one had complained,” James said.

A security guard at Pioneer building said they noticed the water was not clear after fetching it with buckets, and it developed a ‘funny colour’ over time, indicating it was not clean.

“I have recommended to the management that the water be taken to the laboratory for testing,” he said.

When Star visited the buildings, there was evidence that Nairobi Water had sent workers to unclog the drainage systems outside Pioneer House.

These workers refused to speak on the matter, only saying they were “working round the clock” to fix the situation.


The management of the four buildings had advised tenants to only use the water to flush toilets, not for either drinking or preparing food.

For I&M, Nzuki said it had taken about three days for the contaminated water in their tanks to be exhausted.

As a result, they were forced to use borehole water from alternative suppliers as the issue was being resolved.

“You can imagine getting enough water to feed to over 530 clients occupying the entire building. It is so costly, yet Nairobi water has not even told us what the problem might be,” Nzuki said.

He said most offices had opted to buy bottled water, and in some cases employees were told to carry their own drinking water.

“This has disrupted operations and we fear it could easily lead to the spread of cholera and other diseases associated with inhabiting a dirty environment. This should be sorted out sooner rather than later,” a caretaker at Pioneer House said.

A man drinks water from a watering point outside City Hall, Nairobi.
A man drinks water from a watering point outside City Hall, Nairobi.
Image: FILE

Machakos locals suffer diarrhoea as cholera traced to Kajiado

As Nairobi CBD reels from water contamination, which lab tests by the Star have confirmed to be the result of bacteria, another alarm has been sounded at Mlolongo, Machakos county, where thousands of residents have experienced diarrhoea for at least a week.

The Star newspaper ran three sample analyses from the Greatwall Apartments phase 1, 2 and 3, after it was reported that several people had been admitted and confirmed to have diarrheal diseases and two cases of cholera yet to be confirmed by the authorities.

According to the samples, water at Phase1 apartments was certified as safe for consumption, with phases 2 and 3 being classified as not safe for consumption as indicated below.

Graphic illustration of the results.
Graphic illustration of the results.

The capacity of the tanks in Greatwall is 6,000 litres. Each apartment gets water from Export Processing Zone-Athi River (EPZA). The water at Greatwall Phase 1 was emptied in one day and by the time of visit it had not been refilled.


According to Erdemann, developers of Greatwall Apartments, the water is sourced from EPZA and the Machakos Water and Sewerage Company (Mawasco), showing a possibility that other estates along the supply line could also be affected.

Our assumption of contamination was confirmed by the fact that two days after we took the samples, Mavoko Subcounty Public Health issued a statement of possible water contamination.

A victim, who sought anonymity, who was recuperating at South B Hospital, told the Star her house had two casualties.

“The issue started on Thursday but the smell was not that strong. If you tasted the water you could feel a strange smell, but we chose to ignore,” she said.

“On Friday I started to diarrhoea, and by Saturday morning, my sister and I got seriously ill. We sought medical attention and went back to the house, but at night we were admitted here.”

A property manager at the estate said all security officers had taken leave after they suffered severe diarrhoea. 

He said at first, they thought it was the food they had eaten but when the diarrhoea persisted, they had no option but to seek medical attention.

“You can see even the way I am struggling. I took the water in one of the vacant houses and had no idea it was bad. After a few minutes, my stomach was very uncomfortable,” Omasa the manager said.

He said they advised all the tenants to let the water run as they emptied the tanks.

“We have 500 houses in our phase one estate, 384 in Phase 2 and 284 in Phase 3. The first incident was reported at Phase 3, where the caretaker was taken ill. The following day one tenant was taken ill and admitted and when we heard, we called the people from Public Health, who upon testing the water said it was bad,” he said.

Nairobi CBD
Nairobi CBD
Image: FILE

The manager said they get the water from EPZA, whose main source is Nairobi water. EPZA gets the water from the Ndakaini line from General Motors.

We sought confirmation from the Mavoko subcounty Public Health officer Godfrey Mutuku, who said they had received complaints from March 9-13 about possible water contamination.

“Investigations conducted by this office suggest a possible contamination of drinking water supplied by EPZA. Residents and companies have found that water supply received on March 8 had objectionable smell, taste and colour,” read a letter copied to subcounty medical officer of health JW Mbogo on March 15. 

Mutuku confirmed that as a result, five people had been admitted in various hospitals, including Shalom Community Hospital, Kitengela hospital, 24 hospital and Machakos Level 5 Hospital.

He said although it was certain the water was contaminated, it could not be directly linked to cholera, as had been alleged. Mutuku said more samples had been collected for more tests.

EPZA chief executive George Makateto in his response said the company is no longer in charge of the water line, as it had been handed to the management of Mawasco. He said he is not in a position to comment on matters not under his jurisdiction.

On further pursuit, water technicians at EPZA said they suspected that some sewage might have leaked into the water.

“We have had to empty thousands and thousands of litres of water after we learnt of the issue. We are the main suppliers of water to most residential areas, ranging from Mlolongo all the way to Kitengela. Most tenants had complained and we immediately took the samples for testing,” one of the engineers said.

Therefore, for about two weeks, residents have had to depend on an alternative supply from River Athi, water bowsers and private boreholes.

Leave No One Behind

WHO estimates that 1.8 billion people globally use a source of drinking water that is faecally contaminated.

WHO further says inadequate drinking water and sanitation are estimated to cause 502,000 and 280,000 diarrhoea deaths respectively.

In total, 842 000 diarrhoea deaths are estimated to be caused by this cluster of risk factors, which accounts for about two per cent of the total disease burden and 58 per cent of diarrhoeal diseases.

In children under five years old, 361,000 deaths could be prevented, representing about six per cent of deaths in that age group.


In Nairobi’s Eastleigh area, over 100 people had been checked into various hospitals with diarrhoea.

A resident named Mohamed said although the area gets water two days a week, many residents had consumed the water without any idea it was bad.

Mohamed said he raised the issue with public health officers at City Hall, who sent a team that took some samples for testing.

“What was shocking is that they said the water was okay. But we have since been receiving reports of people with diarrhoea across all homes. We are of the opinion that either City Hall is playing us or something is amiss,” he said.

Other cases had been reported in Nyayo Estate, Fedha, Pipeline and Tasia. We tried to get in touch with Nairobi county to confirm whether they were aware of any reported cases.

County director of communications Elkana Jacob refuted the claims, saying there was no case that had been reported. “I live in Nyayo Estate and there is nothing like that. By now it could be all over and action taken,” he said.

But later on, City Hall released a statement confirming a cholera outbreak in Nairobi.

County Director of Health Dr Lucina Koyio urged referral hospitals and subcounties to activate their response teams, saying Nairobi county was experiencing a wave of cholera outbreak, which was confirmed on March 20. The statement was issued last Friday, on World Water Day.

“In this regard, I am requesting all referral hospitals to reactivate their Cholera Treatment Units to prevent the spread of the disease,” Dr Koyio said.

“All subcounties should be on high alert and treat all suspected cases of cholera as cholera cases.”

Chief operations officer Public Health Washington Makodingo in his response said he had not heard of any cases but said we give him a few minutes to seek the information. Several days later, Makodingo could not respond to calls or messages.

According to a tweet by the Kenya Medical Practitioners and Dentists Union, the cholera outbreak started in Kajiado before being confirmed in Nairobi.

“Cholera is contagious. It is spread when water sources, food, fruits are contaminated with bacteria that causes cholera. Take care of your hygiene at this time anywhere in Kenya,” read the tweet.

Nairobi faced a threatening cholera outbreak in 2017. According to the WHO, 3,967 laboratory-confirmed and probable cholera cases, including 76 deaths, were reported by the Health ministry to the World Health Organisation. Of the cases reported, 596 were laboratory confirmed.

This forced the county government to tighten the noose on roadside food caterers and vendors. However, it seems it was a short-lived solution.

The Global Taskforce on Cholera Control estimates that in every 10 seconds, someone gets cholera, even though it is both preventable and treatable. “It kills an estimated 95,000 people a year.”

The World Water Day theme this year was “Leave No One Behind”. Nations are rallying behind targeting cholera hotspots with oral cholera vaccines and WASH (water, sanitation and hygiene), in a bid to end cholera.

WHO estimates that 1.8 billion people globally use a source of drinking water that is faecally contaminated.

WHO further says inadequate drinking water and sanitation are estimated to cause 502,000 and 280,000 diarrhoea deaths respectively.

Nairobi faced a threatening cholera outbreak in 2017.
Nairobi faced a threatening cholera outbreak in 2017.

In total, 842 000 diarrhoea deaths are estimated to be caused by this cluster of risk factors, which accounts for about two per cent of the total disease burden and 58 per cent of diarrhoeal diseases.

In children under five years old, 361,000 deaths could be prevented, representing about six per cent of deaths in that age group.

The best way to avoid diarrhoea-related complications is to report to the nearest health facility for investigation, observe hygiene practices, especially during food preparation, and ensure food is properly stored, covered and served hot.

Other remedies include boiling drinking water, avoiding eating food in unsanitary premises, washing fruits before eating, washing hands before eating and after visiting the toilet.



There are two types of coliform bacteria: total coliforms and E. coli.

Total coliforms are a group of bacteria commonly found in the environment, for example, in soil or vegetation, as well as the intestines of mammals, including humans.

Total coliform bacteria are not likely to cause illness, but their presence indicates that your water supply may be vulnerable to contamination by more harmful microorganisms.

  1. coli is the only member of the total coliform group of bacteria that is found only in the intestines of mammals, including humans.

The presence of E. coli in water indicates recent faecal contamination and may indicate the possible presence of disease-causing pathogens, such as bacteria, viruses and parasites.

Although most strains of E. coli bacteria are harmless, certain strains, such as E. coli 0157:H7, may cause illness.

Health Risks In water

Coliform bacteria have no taste, smell, or colour. They can only be detected through a laboratory test.

The WHO Drinking Water Quality Guideline for E. coli is non-detectable per 100ml of water.

Maximum Acceptable Concentration for Drinking Water is equal to non-detectable per 100ml of water.

This means that in order to conform to the guideline, for every 100ml of drinking water tested, no total coliforms or E. coli should be detected.

E.coli in drinking water indicates the water has been contaminated with faecal material that may contain disease-causing microorganisms, such as certain bacteria, viruses or parasites.

The health effects of exposure to disease-causing bacteria, viruses and parasites in drinking water areas varied.

The most common symptoms of waterborne illness include nausea, vomiting and diarrhoea.

Infants, the elderly and those with compromised immune systems may suffer more severe effects.

In extreme cases, some pathogens may infect the lungs, skin, eyes, nervous system, kidneys or liver, and the effects may be more severe, chronic or even fatal.

You should not assume that your water is safe to drink just because it has not made you sick in the past. If bacteria are present in your water, there is a risk it could make you ill.

Additional reporting by Stellar Murumba, a project manager at Code for Africa.

This story was produced in partnership with Code for Africa’s iLAB data journalism programme, with support from Deutsche Welle Akademie