The Nairobi county government will begin upgrading its sewer lines to reduce the impact of overloading that leads to leakages.
This has been confirmed by the Nairobi Water and Sewerage Company acting managing director Nahashon Muguna.
This follows an order by Governor Mike Sonko that sewer lines in most of the informal settlements be upgraded.
The governor was speaking after holding a morning briefing from county executives, where disaster management, environment, security, health and roads departments highlighted the issues they have tackled so far.
“We need to fast-track the expansion of sewer lines and deal with the leakages being experienced in some areas. Matters environment, health and roads are in my blood streams,” the governor said in a brief meeting with the executive members at City Hall.
The officials on Monday confirmed that the exercise, which will be funded by the county, will kick off in January once the heavy rains stop.
Already lined up is the expansion of the Tasia-Fedha sewer line in Embakasi East constituency.
The line is heavily overloaded with waste water.
The expansion is awaiting the completion on a similar project in the neighboring Savanna ward which kicked off mid this year.
Muguna confirmed that the expansion will see a new sewer line of 375mm put in place from the current measurement of 225mm.
Muguna said that the sewer line was laid in 1980 and has been punctured and destroyed by the road constructions and mushrooming of slums in the neighboring wards.
“The sewer line runs from Tasia Tel Aviv gate to Fedha and Nyayo Estate in Embakasi East,” Muguna said.
This financial year, the county set aside Sh362 million for water and sewerage services.
Most sewer lines in the larger Embakasi have been tampered with by irregular construction of buildings in the past.
“Some of the leakages are caused by the ongoing road works but mostly, they have in the past been tampered with by irregular constructions,” he said.
The construction of the Outering Road has also contributed to the weakening of the sewer line hence more leakages.
The project will be done concurrently with the rehabilitation of Fedha road for proper coordination.
The county will also upgrade the Pipeline-Kware sewer line and the one running from Imara Daima to Mukuru kwa Reuben and Kwa Njenga slums.
According to Veska Kangogo, the county executive member for environment, water and sanitation, the sewer lines have gone for over 30 years after being upgraded and the overload is overwhelming.
“The last time sewers were upgraded in the city was 1987 when the water supply production was 270,000 m3/day,” she said.
In 1997, the third Nairobi Water Supply Project was completed and added 255,600 m3/day into the system but the sewers were not expanded accordingly to carry the extra waste water.
“Today, most of the sewers flow above half bore instead of flowing below half bore. Therefore the sewer lines in the city are overloaded with waste water besides the storm water being directed into the same, worsening an already grave situation,” she added.
She revealed that area re-planning has also been done in Umoja, Eastleigh and Kilimani without upgrading of the water and sewer infrastructure.
Population growth is also to blame, according to Kangogo.
“There has been population explosion in the city where private development of residential estates has taken place without similar expansion and extension of the sewers leading to most of the resident laying on site sanitation system which when full discharges in the open drainages hence pollution of the rivers,” she said.
This implies that the pipes have pressure lower than one atmospheric pressure.