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Desalinated sea water for city in four years

Posted by: Saving Water SA (Cape Town, South Africa) – partnered with Water Rhapsody conservation systems – 23 April 2010

By: Jeremy Westgarth-Taylor
Pioneer of Water Rhapsody Conservation Systems and winner of a WWF Green Trust Award

The Table Mountain fossil aquifer has been there for millions of years. Extraction would permanently reduce the amount of water.

Water and Environmental Affairs (DWEA) Minister Buyelwa Sonjica has said that her department was forging ahead with plans to supply desalinated water to Cape Town, and furthermore extract water from the Table Mountain (TM) aquifer.

As mentioned in the article, all rivers in the Western Cape have been dammed, and the maximum amount of water is being extracted. There is no more water that can possibly be squeezed from our rivers.  What was not said is that this water is used, polluted and largely wasted to rivers around the Western Cape with concomitant damage to riverine and marine life.

The focus has always been and remains to supply more and more water.

Now DWEA are looking at other ways, hence the aquifer extraction and sea water desalination. Has the Minister not been advised by scientists that by extracting fossil water from the TM aquifer, the relatively finite amount of water in the aquifer is being permanently reduced for all practical intents and purposes. This is a fossil aquifer, and has been there for millions of years. Not only would extraction permanently reduce the amount of water in the aquifer, but it would also jeopardise plant and animal life as well as rivers within the aquifer system. If you for instance pump water out near Cape Town, there will be a lessening of available water as far as Port Elizabeth!

Desalination plants are able to send distasteful but pure water to Cape Town, but how do desalination plants dispose of the high saline water once the pure water has been extracted? This high saline water is sent back to the sea.  The plants and animals that are found within the sea current of this highly saline water are likely to be adversely affected. This is aside from the higher cost of the water to consumers.

One of the problems with supplying more water is that this means more water goes into the sewers. Local sewage plants spill up to 35% of the volume of raw untreated effluent into estuaries, rivers canals, and directly into the sea.  This is because they are not able to cope with the current amount of water passing through them, let alone any future augmented amount. The money charged for the treatment of sewerage is not currently being put back into maintenance and building of new sewage treatment works. This money is used elsewhere.

Not only does this mean that there are plans to use water which is not sustainable, but treatment of the effluent which is not currently sustainable, is going to be further degraded.

To put this very simply:  Desalination of sea water is not sustainable.  This process of supply of water destroys the sea, land and air.  Removal of ground water from the TM Aquifer is not sustainable.

Rather put the money that you would have spent on your proposed but unsustainable augmentation systems into education, to teach people to use less water.  After all the first democratic Minister of Water Affairs Prof. Kader Asmal, said:  “Ways must be found to use less water”. Instead of augmenting the supply of water, the demand for water must be managed and reduced. There are many ways to do this, but at present none are being prioritised. The recent water week passed unmentioned (and probably unnoticed) by government or the press.

Eskom has made environmentally laughable their rebate system for solar geysers with their new loan to build a huge coal fired generating plant – with the biggest ever loan given to anyone by the World Bank. I appeal to the Department of Water and Environmental Affairs not to make a similar environmental fool of themselves by giving lip service to the use of less water (which is all the effort they are currently putting into the management and reduction of the demand for water) while at the same time introducing new unsustainable and environmentally unsound water supplies.

Never has it been truer, that energy and water are inseparably intertwined.   Each kilowatt hour of electricity generated in South Africa costs 1.32 litres of water, making ESKOM the biggest single consumer of water in the country. This situation is made far worse by adding dirty power for manufacturing clean water to the list of environmental misdemeanours.

This announcement to desalinate sea water is just too close to the announcement last week of the approval of the building of this new power station. Has our Minister been asked to spend some of this new electricity supply on energy hungry desalination plants? Any thoughts about environmental matters?  Water and Environmental Affairs fall within the same Ministerial Department. It seems that Environmental Affairs is currently being sidelined to the detriment of the country.

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