Water supply has resumed in some parts of Nairobi four days after Ng'ethu water treatment plant was closed to avoid the flow of muck in taps.
Most of the water was by Monday evening being supplied to densely populated informal settlements of Mathare, Mukuru, Korogocho and Kibera.
“South B, Lang’ata, Kilimani, Lavington, Westlands, Kariobangi and Nyayo Embakasi, estates along Mombasa Road and the Central Business District started receiving water,” Nairobi City Water and Sewerage Company said in a statement.
The shutdown of the Ng'ethu plant, which supplies 85 per cent of water in Nairobi, was attributed to the flow of muddy water in the treatment works from the Aberdare Forest, River Chania's catchment area.
Heavy rains in the Aberdares have caused mudslides, with mud washed down River Chania and into the water treatment plant since last week. Friday and Saturday were the most affected days, according to NCWSC.
The Mwagu intake along River Chania was clogged and the turbidity level was high.
The rest (15 per cent) of Nairobi water supply is sourced from Sasumua, Kikuyu Springs and Ruiru dam.
“Even after unclogging of the intake, the turbidity levels were quite high and the raw water was not responding to clarification/ treatment chemicals,” the water company said.
Turbidity is the quality of being cloudy, opaque, or thick with suspended matter. Its measurement is a key test of water quality.
NCWSC production manager Philip Githinji told the Star on Monday that the situation is “fluid.”
Ng'ethu's treatment capacity is 18,333 cubic metres cubic per hour or 440,000 cubic metres per day.
“We are treating water from 11pm at 90 per cent of the capacity to comply with quality standards set by the regulator.
"We are dealing with very high turbidity of above 5,000 NTU (Nephelometric Turbidity Units) causing us to temporarily shut the systems then resume once turbidity goes down," Githinji said.
The normal raw water quality for 85 per cent turbidity is below 100 NTUs.
WHO requires potable water to be below five NTUs after treatment.
Githinji said conventional water treatment system like Ng’ethu treats up to 800 NTUs.
The weekend shutdown affected the City Centre, University of Nairobi main campus, Coca Cola factory, Jomo Kenyatta International Airport, EPZ-Athi River, South B, South C and the neighbourhoods.
The Industrial Area, Mlango Kubwa, Mathare, Eastleigh, Moi Airbase, Huruma, Kariobangi and Pangani were also affected.
The other areas were Maringo, Buruburu, Bahati, Outering, Baba Dogo, Dandora, Dandora KCC factory, Umoja, Donholm, Fedha, Tassia, Avenue Park, Nyayo and Embakasi.
The taps were also dry in Ruai, Njiru, Kayole, Komarock, Kenya Breweries, Kenyatta University, Kahawa Barracks, Kasarani, Mwiki, Kahawa Sukari, Garden and Thome estates.
The areas affected on Limuru Road are Parklands, Ngara, Aga Khan Hospital, University of Nairobi's School of Law, City Park, Gigiri, United Nations and Muthaiga.
On Monday evening, the company said customers will be receiving water in low pressures until the system normalises. “We have remodelled the water distribution programme to ensure all the residents receive water as soon as possible.”
NCWSC advised its customers to use the water sparingly even as one of the Covid-19 interventions is washing hands frequently with running water for a minimum of 20 seconds.
Edited by - mwaniki fm
