88 days to Cape Town’s Day Zero: Will it be ok to flush with sea water?

12 Feb 2018


It’s 87 days to go before Cape Town hits #Day Zero, a day when water taps are set to run dry in South Africa’s second largest city with a population of four million.

If and when Cape Town hits Day Zero currently scheduled for 11 May 2018, there wont be water to flush toilets.  Will it be ok to flush with sea water?

The World Wide Fund for Nature (WWF)  considered this question and compiled the following answer:

Flushing with sea water in the metropolitan area is NOT an option.  Sea water flushing will increase salt in the waste water treatment plants, and if the salinity levels get too high the microbes which treat the sewage can’t survive and the treatment plants will stop working. Then we would end up with an even bigger problem as our waste water plants would become inoperable.  The same principle applies to septic tank systems which rely on microbes to decompose the sewage. Suburbs on the Atlantic seaboard (Green Point, Sea Point, Camps Bay and Hout Bay) discharge sewage out to sea via a pipeline; under emergency conditions you can flush with sea water in these areas but the salinity may damage the infrastructure.


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