Water is made up of hydrogen and oxygen. It also contains other minerals like calcium, magnesium etc.

Clean water should always appear colourless and odourless.

NWSC has a number of different water sources. These include: Lakes, Rivers, Dams, Swamps, Ground water.

All these water sources are rain fed. NWSC abstracts the water and treats to standards that are safe for human consumption

In simple terms, hard water is:
Water that does not easily form lather with soap when washing/bathing.

Water that forms scales in boilers such as kettles, water heaters etc.

They are two types of hard water:
Permanent hardness caused by high concentration of magnesium and calcium salts of sulphates and chlorides
Temporary hardness is mostly caused by magnesium and calcium salts of bicarbonates

Hard water is not harmful and it is a useful source of calcium for a healthy bone development

Magnesium is useful for nerve and muscle function, immune system, steady heartbeat, bone development etc.

The National Standards for total hardness is 300 mg/L. NWSC water maybe hard but meets the standards
Permanent hardness is not easily removed; it requires specialized treatment which may increase the cost of water.

Temporary hardness is easily removed by boiling

Causes of smelly water:
Dirty overhead tank
Contamination as a result of poor plumbing
Stagnation of water at dead ends of supply network
Dirty home water filters

If overhead tanks are not covered, birds can bring dirt in the tanks. This can decompose and cause the water to smell. Rectify by covering tanks followed by periodic cleaning of the tanks.

If the sewage and clean water pipes are mixed up, contamination can occur in the event of pipe damage. This can cause water to smell. Rectify by separating sewage and clean water pipes during plumbing.

Water stagnating at the last points in the water supply pipes can cause smell. This can be rectified by NWSC periodically flushing the network

Causes of coloured water:
Brown water

-Intrusion of dirt when pipes are cut during road works.
Dirty overhead storage tanks agitated while filling.
-Intrusion of dirt during repairs
-Intrusion of dirt in leaking pipes during low water pressure
-Rusting of galvanised Iron pipes

Whitish colour

-High pressure and air bubbles can make the water at the tap appear whitish. This is not harmful

Immediately report to NWSC; the water lines will be flushed to remove the brown water.

Regular wash overhead storage tanks, at least twice a year.

In case of any other observations, immediately call NWSC Water Quality team.

Reservoirs are usually washed twice a year

All NWSC Areas have a cleaning schedule that is followed. However, cleaning of reservoirs and all the other water treatment units are sometimes done before schedule when need arises as informed by the monitoring quality results.

The pipes are changed when need arises but generally, each type of pipe has a life span e.g.
-Steel pipes (20 – 50 years)
-PVC pipes (20 – 30 years)

NWSC does periodic operation and maintenance and any old pipes identified are replaced.

Daily reports are found on the NWSC website

Major water quality parameters for the NWSC Areas are posted on the website.

-Yes, NWSC water conforms to both the UNBS standards and WHO guidelines.

-Each indicator of good water quality specified by UNBS has its limit.

-The critical parameters (color, turbidity, microbiology, residual chlorine and Aluminium) are monitored on daily basis before the water leaves the water treatment plant. Daily monitoring is also done in the supply network.

-Joint Water Quality Monitoring between NWSC, UNBS, MWE and KCCA is periodically conducted. The different organizations analyse the samples independently and a joint meeting is held to discuss the results

-MWE conducts independent monitoring of all the water treatment plants in the country