Sewage mess: Change of tack in war on killer diseases


When you hear cholera, typhoid or diarrhoea, contaminated water comes to mind

Wednesday March 18 2020

Mtu wa mavi or poop man. This is what residents of Karagita in Naivasha call Thomas Maela, the man responsible for ridding their homes of human waste.
He marches from door-to-door carrying the waste he collects from portable toilets found in at least 130 houses in Naivasha. The neighbourhood has adopted the use of a portable toilet, known as a Blue Box, to solve their sanitation problems.
At least 89,000 people die every year due to poor sanitation. Out of those, 3,100 are children killed by diarrhoea alone.
A 2017 data analysis for Sustainable Development Goal 6 shows the number of Kenyans using safely managed sanitation services stood at 20 per cent. This meant 80 per cent of Kenyans were using unsafe sanitation services.
Poor sanitation is linked to transmission of diseases such as cholera, diarrhoea, dysentery, hepatitis A, typhoid and polio and exacerbates stunting, according to the World Health Organisation.
Human waste is filthy and can be a source of disease. But, it can also be a source of water, fertiliser and energy if managed well. According to Water Cabinet Secretary Simon Chelugui, Kenyans spend a whopping Sh57 billion to treat waterborne diseases every year.


At a time when the government is struggling to find a solution to the sanitation problem affecting millions of Kenyans, communities have turned to technologies like Blue Box. The portable toilet has a bucket and a round plastic can inside. It allows the separation of urine and faeces when someone goes for a call of nature and is small enough to take up space inside the house.
People like Maela, a toilet service representative working with Sanivation — a social enterprise based in Naivasha which moulds the Blue Box — are charged with cleaning up the mess every four days a week.
“They call me mtu wa mavi, but I am used to it,” he says during an interview with HealthyNation.
Once waste is collected from a Blue Box, it is treated through heating at very high temperatures to kill pathogens and remove the odour. It is then converted to either super balls (purely human waste briquettes) or super logs (sawdust mixed with human waste at ratios), two sources of green energy for use at home, factories and institutions.
For 37-year-old Evelyne Kwamboka, the toilet could not have come at a more crucial time. The mother of four and a resident of Karagita has been using the toilet for the past one year. Thanks to Maela’s services she has not fallen ill. In terms of security, she says it comes in handy as she no longer has to go outside at night.
“This toilet has really helped me because I could not stand the shared pit latrine in our compound. The latrine is very dirty and I was concerned about my children’s health,” she says during an interview, minutes after Maela had services her toilet. During a cleanup, Maela exchanges used buckets and cans contained in the Blue Box, with clean disinfected ones.
“Some people say they cannot keep a toilet in the house, especially because they cook and eat there. But, it is ironical because they use the normal bucket at night and throw out the waste in the morning,” says Kwamboka.
When she took the toilet home, her daughter refused to eat because it was placed inside the house. She found it unhygienic. But, she later got used to it after realising it was safe, says her mother. Blue Box users are taught how to keep off odour.
After using it, the waste is covered with charcoal dust. The dust helps contain any odour that can attract flies or make the house inhabitable.

According to her, the box is an excellent innovation because it helps prevent waterborne diseases. On average, Kenyans spend at least Sh1,200 per person annually to treat these preventable waterborne diseases, according to a study conducted by Japanese sanitation firm LIXIL.
Kate Bohnert, the business development manager at Sanivation, says Blue Box targets the larger population — the non-sewered Kenyans in secondary cities, towns and slums where the sewage system is non-existent or inadequate. This is because only one sewage treatment plant can cover an entire community in such areas, she says.
Among cities and big towns in Kenya, it is only Nairobi which has 50 per cent sewerage coverage.
“For example, there is a huge problem at the Kakuma Refugee Camp because the area is dry. Access to water is a huge challenge, and, so, this kind of technology is helpful for the refugees,” says Bohnert.
This is one example of onsite (decentralised) treatment of sewage, which the Water Ministry is now advocating.

Counties use the centralised sewage treatment method (treatment away from the point of generation), unimproved or limited sewage management sanitation services.
According to Water Services Regulatory Board, only six per cent of sewage is safely transported and treated offsite, 27 per cent of Kenyans are using private improved onsite sanitation, 40 per cent use limited sanitation services, eight per cent (unimproved sanitation services) and 12 per cent (six million) defecate in the open.

On average, a normal human being produces at least 150 litres of waste water every day, and 500g of faeces, which translates to 3.5kg per week and 182kg per year. Considering this, new technologies have come up to handle waste in a safe way that prevents waterborne diseases.

Miles away from Naivasha, in Nakuru town, Nawasscoal — affiliated with the Nakuru Water and Sanitation Services Company — is also treating waste onsite. Nawasscoal has adopted decentralised treatment of sewage, which requires a small space, compared to the conventional treatment plants, to clear the human waste in Nakuru and its environs.
Just like Sanivation, Nawasscoal collects sewage from exhauster trucks, treats it and produces carbonised briquettes from dried faecal sludge.
Besides leaving the environment clean and safe, the briquettes have replaced the use of charcoal and tree logs for energy production, thus saving trees and forests, says Mr John Irungu, the general manager of Nawasscoal.
In Nairobi, sewage is used to produce biogas and clean water for domestic use. Bio-centres have been built in major slums in the city. One example is the Kibagare bio-centre.
Before it was constructed years ago, Ms Josephine Munyiva would wake up to faeces on the roof of her house.
Edward Kilonzi, a resident of Mukuru Kayaba slum, talks of a similar situation before the construction of Kayaba Ushirika wa Usafi na Maendeleo (Kuum) bio-centre, where he is a member. “Flying toilets were a nuisance. The faeces would be thrown on the roof of our houses. But, that is in the past,” he says.
Bio-centres use a simple technology to treat human waste besides producing biogas for lighting and heating. For example, the Kibagare bio-centre serves at least 300 people per day. It is also connected to two public toilets which drain sewage through gravity to a biodigester placed inside a dome.
After treatment, faecal sludge is drained into a holding underground tank which is evacuated once or twice a year depending on the volume of waste.
This sludge could be treated further and converted to fertiliser or any other end product, but presently it is not happening in the 90 such facilities in the country due to financial constraints.
Bio-centres are common in Kibera, Mukuru Kayaba, Mathare, Kibagare and other urban slums across the country, says Umande Trust Managing Trustee Benazir Omotto.
These centres have become a saviour, considering that urban slums are not connected to a sewer line.
“Pit latrines were many in Kibera in 2004. They would be abandoned whenever they were full. This used to be a disaster during the rainy season because all the waste would be washed down the drain by water,” says Omotto.
This is worsened by the narrow paths which make it hard for exhauster trucks to access the houses. “Large volumes of sewage still drain into Nairobi dam. We have not closed the sanitation loophole because we are experiencing some limitations,” says Omotto.
However, as Omotto says, night time access to the bio-centres is a challenge and solutions like the use of portable toilets are needed.

But poor sewage management is not a preserve of the urban poor. High and middle class residential areas have not been spared either. Some of the houses are not connected to the sewer line and end up discharging sewage into the environment. As such, EcoCycle, with a focus on homeowners and developers, has been installing onsite sewage waste management systems in hotels, institutions and homes. EcoCycle has installed the system in Syokimau and Kitengela.
Through an advanced technology and a biological process, EcoCycle converts waste water to clean reusable water.
Lucy Mutinda, the director of EcoCycle, explains the treatment of human waste. Bacteria eat the organic waste (faecal matter) collected in an underground chamber, and produce water which homeowners can use to irrigate gardens and lawns, flush toilets, wash car parks among others.
If the water can be purified further, it can be used in the house for other purposes. But she says the process is expensive. “The most critical pathogen is e-coli, and that is why the water is passed through a chlorinator system which helps to eliminate it. However, it is not good for human consumption because it has nitrates which are good for the plants but not for the organs,” says Mutinda.
The system is compressed in such a way that it can be constructed on the lawn, garage and parking or even the basement of a storied residential building.
Just like Nawascoal, the system used by EcoCyle can take up a space as small as two metres by six metres for a household of five to 10 people.

At least 400 people in 58 houses at Almond Grove estate in Kitengela are beneficiaries of the system. The estate’s underground treatment chamber occupies a space of 10 metres by 15 metres.
Mr Nicholas Bitok, the manager of Almond Grove, tells HealthyNation the system produces 45,000 litres of reusable water in 24 hours.
The sediment produced after the aerobic process can be dried and used as manure, while the carbon dioxide produced is released back into the environment, says Mutinda.
According to Festus Mutuku, a sewerage and sanitation expert at the Water ministry, technologies in sewage management provide solutions. “Safely managed sewerage and sanitation can reduce the cost of medication, premature deaths and productivity losses related to waterborne diseases,” he says.
According to him, onsite sewage treatment is easy to implement because it requires a small area of land and is low cost compared to offsite treatment which requires a network of infrastructure, big pieces of land and huge cost of implementation.
WHO attributes some 827,000 deaths each year in low- and middle-income countries to inadequate water, sanitation and hygiene, which represents 60 per cent of total diarrheal deaths. Poor sanitation is believed to be the main cause in some 432,000 of these deaths, states WHO.
In the US, more than one in five homes are served by individual or small, clustered wastewater systems, which collectively treat more than four billion gallons of sewage daily, according to US Environmental Protection Agency, Office of Wastewater Management.