04/12/2017 07:37 SAST | Updated 04/12/2017 07:37 SAST

Water From Cape Town's Desalination Plants Could Pose A Health Risk

The plants are key to the City's plan to prevent Day Zero.

Normally submerged tree stumps are seen at Theewaterskloof dam near Cape Town, South Africa, June 2, 2017. The dam supplies most of the city's potable water.
Mike Hutchings / Reuters
Normally submerged tree stumps are seen at Theewaterskloof dam near Cape Town, South Africa, June 2, 2017. The dam supplies most of the city's potable water.

The City of Cape Town's mooted solution to its water crisis, desalination plants, could also pose a health risk to city residents, The Times reported on Monday.

Four desalination plants are due to start operating in February next year, and are a large part of the City of Cape Town's plans to stave off Day Zero next year, as its water crisis escalates.

The City has reportedly budgeted R95-million to implement measures to combat the drought, IOL reported. These include installing boreholes in rural areas and supplying water tanks.

The City said that, while it was confident that taps will not run dry, level 5 water restrictions will be in place throughout the holidays and that should Day Zero arrive, when dam levels reach 13.5% capacity, almost all taps will be switched off. Residents will have to queue for water and densely populated informal settlements will be prioritised.

Scientists from the Western Cape's top universities came together to investigate the desalinisation plants, led by Professor Leslie Petrik of the University of the Western Cape's environmental and nano-science group. Their report, published in the December edition of the "SA Journal of Science", reportedly says:

"It is probable that the water recovered from desalination may still be contaminated with traces of complex pollutants after the [desalination] process... This probability represents a public health issue."

This is reportedly due to the 36-million litres of effluent that is released by the city into the ocean per day.

A report commissioned by the Council for Scientific and Industrial Research (CSIR) reportedly says that there is a good possibility that the faecal effluent from the city could reach the shoreline.

The report, released two weeks ago, says shoreline water samples showed bacteria counts "high enough to suggest a significant periodic risk to human recreation in near-shore and shoreline waters".

However, the City of Cape Town says the water from the desalination plants is not a health risk.

Xanthea Limber, the City's mayoral committee member for water and waste service, told The Times that the desalinated water would meet the same standard as dam water.

"The water produced from desalination will be tested daily for conformance with the standard. Complex chemical pollutants will not be present in sufficient quantities to place the public at more risk than they would be just living in an urban environment where these chemicals are freely used," she said.

The City still needs residents to cut their water usage to 87 litres per person per day, but many Capetonians have yet to heed this call.

On Sunday, City of Cape Town mayor Patricia de Lille said there were three properties were averaging 1,000 litres per day, News24 reported. The properties are located in Pinelands and in Thornton.

She reportedly said many high water users have prevented City staff from accessing their properties to install meters and had even become so aggressive that law enforcement had to accompany city officials to the properties.