The lively laughter of children playing outside welcomes you to the vibrant Thome neighbourhood, a stark contrast to the unpleasant environment that once plagued the estate due to dangers from exposure to open sewers and flowing sewage.
This was not the case a few years ago.
Before, the now clean middle-class neighbourhood was characterised by the pungent smell of raw sewerage, and the sight of open gutters with flowing waste, posing serious health risks to the community, particularly growing children.
Bustling under an ever-increasing urban population, Nairobi’s sewerage system is currently unable to sustain the four million-plus population that inhabits the city.
Open gutters blocked drainages and flowing sewers have been a sore sight in Kenya’s capital city, contributing to an increase in cases of waterborne diseases like cholera, typhoid and dysentery, especially in children.
To ensure neighbourhoods in Nairobi have cleaner streets and proper waste disposal systems, the government partnered with the African Development Bank.
Phase 2 of the project will increase the city’s sewerage coverage by more than 50 per cent.
It is titled the Nairobi Rivers Rehabilitation and Restoration Programme: Sewerage Improvement Project (NaRSIP).
The project started in August 2020 and is set to be completed by December next year.
The first phase of the project was completed in 2017 and increased sewerage coverage in the city to 48 per cent.
This was achieved with the construction of 56 km of trunk sewers and 40km of reticulation sewers.
During Phase 1, the Dandora waste water treatment plant was expanded to handle 40,000 cubic meters of waste per day, while the rehabilitation of Kariobangi waste water treatment plant was rehabilitated to a daily capacity of 32,000 cubic meters of waste management, up from the initial 11,000 cubic meters.
The rehabilitation and restoration are under the Athi Water Works Development Agency, one of the nine Water Works Development Agencies established under the Ministry of Water.
DRAINING SEWAGE
To effectively serve Nairobi residents, NarSIP has been divided into five lots, covering Kahawa West and Sukari, Githurai 44 and 45, Mwiki and Clayworks, and the extensive East and West areas of Nairobi.
These areas have undergone remarkable transformation since the sewer line was constructed.
The once unsavoury environment has been turned into a serene space for residents.
Open sewers and floating waste are now a thing of the past.
The air is cleaner, devoid of the foul smells emanating from stagnant waters.
Children can be heard playing and giggling outside, and their parents no longer worry about their health.
Susan Gakii, a resident of Marurui Estate, recounts the experience of having to drain raw sewage using buckets, which posed a great health risk to her and the children.
With the accumulation of sewage in and around the apartments, there was a surge of mosquitoes, she said.
“We used buckets to drain the sewage after every 30 minutes, even the one that came from the toilets. But now with the connection of the sewer line, life has become simple, children can now play outside freely,” she said.
Schools, hospitals and other public institutions are among those that have gained from the sewer system in addition to the residents of the adjacent Thome Estate.
Ruaraka Academy Head of IT Karani Waruhiu said the institution has significantly benefited from the project.
During the rainy season, the school would hire exhauster trucks to drain the sewage.
“Since we transited to the sewer system, it has been a big relief to us. The exhausters came at a significant cost, which impacted the finances of the school, and we constantly had to deal with overflowing sewage, which affected the health of the children,” he said.
Moreover, the noise caused by exhauster trucks disrupted classes and affected the environment.
Grace Muthoni lives in Githurai and oversees a couple of apartments in the area.
She had to grapple with frequent issues of drainage blockage prior to the construction of and connection to the sewerage system.
The toilets would block and spill on the roads, exposing residents, especially children, to health risks.
Further, draining the sewage using exhauster trucks resulted in unwanted noise, smoke and smell.
“Now sanitation has improved a great deal, with most apartments connecting to the sewer line. The health of residents has also improved, with a reduction of illnesses being reported,” she said.
GROWING THE CAPACITY
The Rehabilitation and Duplication of Dandora Estate Sewage Treatment Plant aims to double the capacity of the waste treatment facility.
The plant occupies about 4,000 acres and is located 26km from Nairobi city on Kangundo Road, east of the city along the eastern bypass at Ruai.
The treatment plant treats domestic and industrial waste of about 120,000 cubic meters per day, which is equivalent to about 80 per cent of wastewater generated from Nairobi city.
NaRSIP II Lot 1 resident engineer Duncan Kamau said the treatment of the wastewater involves two processes: physical and biological treatment.
In the first instance, the raw sewage is directed to the plant for screening, where large materials, such as pieces of cloth or sack, are removed.
“Under the physical treatment, the wastewater at the inlets is passed through coarse, intermediate, fine screens, dirt trap and compactor to remove large materials from the wastewater,” Kamau said.
He said the waste water passes through anaerobic ponds and facultative ponds and finally flows to three maturation ponds during the biological process.
Kamau said the depth of maturation ponds allows the sun rays to penetrate to aid in the elimination of pathogenic organisms, such as E. coli.
He said the wastewater quality is monitored daily for the inflow, outflow, upstream and downstream and along the series monthly.
The project includes the construction of secondary reticulation sewers aiming to address the existing gaps in the city’s sewer network coverage and heighten accessibility to sanitation services.
This is especially the case in informal settlements like Kibera, where sanitation is a major problem.
To promote ecological health and help mitigate climate change, the project’s strategy includes tree planting on the sewer line to safeguard riparian zones.
Biogas will be converted to energy at the wastewater treatment plants, implement methane gas collection and reduce greenhouse gas emissions.
Kamau said Lot 1 has progressed to at least 74 per cent and that it is nearing completion, adding that no raw sewage is being released into the rivers.
The other four lots, located in Nairobi’s informal settlements, collect sewage and drain it into the treatment plant for the rehabilitation process.
This is possible through manholes constructed around the communities to discharge sewage to the Dandora Waste Water Treatment Plant in Ruai, where it is treated for safe release into Nairobi River.
There is also a sewer along the Nairobi River from Dandora dumpsite to Gitwamba called the Dandora Dumpsite Trunk Sewer.
The main focus is to connect sewers to estates and institutions in Nairobi to enable the direct flow of sewage to the treatment plant.
MANAGING RIVER POLLUTION
Nairobi hosts about nine per cent of Kenya’s nationwide population, which was tallied at 47 million in the 2019 census but has since increased by about nine million.
A steady increase in rural-urban migration has plunged the city into a sanitation crisis, straining the already existing sanitation facilities that cannot accommodate the ballooning city population.
This has in turn hurt public health, the environment and the economy. With lessons learnt from Phase 1 of the Nairobi Rivers Sewerage Improvement Project, the government embarked on the second phase of the project.
Infrastructure development acting director at Athi Water Works Development Agency Bonnie Nyandwaro said the project is timely.
“There is a lot of pollution and degradation in the five rivers flowing through Nairobi City. These are the Nairobi River, Ngong River, Mathare River, Kiu River and Riara River,” Nyandwaro said.
“The primary objective of this project is to increase the sewerage coverage from 48 per cent to 55 per cent within the city.”
On completion, more than 400,000 residents of Nairobi will have access to improved sanitation services.
Currently, the project is at 82 per cent completion and is being implemented through five lots covering the East and West of Nairobi.
Nyandwaro said sewer networks have been implemented around Githurai, Kahawa West and Mwiki Clay works by eliminating open sewer flows and sewer flows into the Nairobi River.
In areas connected to sewer systems, she said, no illness, especially cholera, has since been reported.
“In areas where there is poor sanitation, there will be contamination,
where children and young mothers
are exposed to health risks. The project seeks to eliminate that,” he said.
