Cape Town - Concerns over Cape Town water being unsafe to drink is a load of rubbish, say city officials and a UCT expert.
There have been a number of claims on social media that due to the declining dam levels – which are at 27.3 percent, with only 17.3 percent that can still be used – tap water tastes and smells bad. There have also been claims people are getting sick from drinking the tap water.
Xanthea Limberg, mayoral committee member for informal settlements, water and waste services and energy said the water is safe.
She assured residents the water quality is closely monitored via a number of samples analysed according to the stringent SA National Standards (Sans 241:2015) requirements.
“We are experiencing high levels of geosmin in the water drawn from the Theewaterskloof Dam. Geosmin is a naturally occurring organic compound which has an earthy flavour and aroma and which is sometimes present in water."
It poses no threat to health.
“Minute concentrations can be detected by the incredibly sensitive human palate."
Professor Neil Armitage, head of department at Urban Water Management, UCT, said although levels are low, the treatment works ensure water remains safe for drinking.
He said the city operates treatment works that do a number of things.
If people are getting stomach bugs, he said, this has to do with the season.
“If this is happening then it is more likely to be because it is autumn and the new ‘bugs’ are arriving from other parts of the world.
"For example, I had a bad dose of bronchitis just over a month ago – but I think this was a secondary infection after I caught a cold sitting next to an infected person on the plane back from the Netherlands.”
But he said it is true that the city’s drinking water is “often slightly coloured brown as a result of the turn-over in the water in the reservoirs as we move from summer into autumn”.
“The water literally inverts itself as the surface water cools down and sinks and the cooler water near the bottom of the reservoir rises to the surface carrying all sorts of muck with it. Of course this is exacerbated if the water levels are low. The city usually uses activated carbon to clean up the water, but this is not always 100 percent effective. However, this is more an aesthetic treatment than a health one.”
He also added that smell and taste of the water doesn’t make people ill, but rather the pathogenic organisms.
The concerns are that because water levels are low, there is more sediment in the water, that could pose a threat to health.
But Armitage said this is not always the case.
“Although these are often found linked to sediment. If sediment is a problem, local authorities will generally compensate by increasing the level of disinfection through chlorine, ozone or ultraviolet light.”
He said simple water tests by the local authority should prove whether there is a problem with the water.