South Africa

Cape Town Scraps Desalination Barge Plan as Water Crisis Eases.

Cape Town’s city council scrapped plans to hire a desalination barge to supplement the city’s water supply after good winter rains helped ease the worst drought on record.

South Africa’s second-biggest city will continue implementing other projects to ensure taps don’t run dry, including curtailing usage by reducing the water pressure and tapping underground aquifers, said Xanthea Limberg, the mayoral committee member for water and waste services.

 

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CoCT amends water by-laws to hit landlords and plumbers hard.

The City of Cape Town has approved a number of amendments to the water by-laws.

According to Mayco Member for Informal Settlements, Water and Waste Services Xanthea Limberg, the amendments include that new developments within the City must ensure water conservation and demand management systems as part of their planning applications.

The City will have to approve these applications beforehand.

 

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This Innovative Technology Harvests Water from Cooling Towers.

To a researcher like Kripa Varanasi, an associate professor of mechanical engineering at MIT, a big nuclear power plant similar to the one that generates electricity near Cape Town, South Africa, is a fountain of water just waiting to be tapped.

The 1,800-megawatt Koeberg Station drinks in water from the nearby Atlantic Ocean and uses it as part of its thermal cooling cycle. Just as in other industrial settings, cooling towers are an inherent part of the power plant’s steam cycle.

As the reactor heats ultra-pure water to create steam to spin a turbine and generate electricity, a cloud forms and rises from the cooling towers, akin to the plume of “steam” that wafts from the brim of a hot cup of coffee.

 

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Desalination for Cape Town – Numbers and Facts – South Africa

3. What about in South Africa?
In South Africa desalination is used quite widely by mines to clean up polluted mine water and acid mine drainage. Small to medium-scale desalination has also been used in coastal towns during times of drought. Six municipalities are currently using small-scale reverse osmosis plants to desalinate water for bulk water supply.

Mossel Bay has a medium size desalination plant capable of producing 15 million litres of potable water per day but the plant is currently on standby as the dams in the area are full. Standby mode requires continuous maintenance to keep the plant functional which costs the municipality money whilst not producing any water.
The Knysna municipality has a desalination plant capable of producing 2 million litres per day which is currently shut down for maintenance and repairs. During normal operation, the plant is used at the discretion of the municipality. Currently there is sufficient water in Knysna so use of the plant is minimised due to the high operational costs.
Plettenberg (Bitou municipality) has an operational desalination plant producing 2 million litres per day.
There are two desalination plants in the Ndlambe municipality, namely the Bushman’s River Mouth and Cannon Rocks plants, that produce 1.8 and 0.75 million litres per day respectively. Both plants are currently producing at full capacity.
The Cederberg municipality has a plant in Lamberts Bay with a capacity of 1.7 million litres per day (upgradable to 5 million litres per day); however, this plant is not operational yet as it is still newly developed.
Richard’s Bay has a desalination plant that was installed during the 2016/17 drought to provide the town with 10 million litres per day. It has been operating at an average rate of 6 million litres per day. The plant has had several problems, particularly cable theft, which has interrupted supply, and excessive pressure, which resulted in pipe bursts in the areas receiving water.
4. What desalination is in the pipeline for Cape Town?
Four of the seven augmentation projects that will bring new water online for Cape Town are desalination plants. They are based at the Waterfront, Cape Town harbour, Monwabisi and Strandfontein (the latter two on the False Bay coast). These are relatively small-scale operations. The City has been criticised for initially trying to bring on smaller and quicker plants to provide water during a Day Zero scenario as these are more expensive. At one stage we were going to bring in desalination barges. Barges have only worked successfully in more sheltered sea areas in the Red Sea and the Gulf. There is very little international capacity in this market at the moment, and this is currently not a viable option for Cape Town. Barges are also generally more expensive than land-based desalination.

5. So why aren’t we doing more desalination in Cape Town?
For arid and drought-stricken coastal cities, desalination can be an important source of water which is completely independent of local rainfall. However, desalination remains the resource of last resort for most cities because it is the most expensive. Desalination takes longer to bring online than drilling the shallower boreholes in Atlantis and the Cape Flats. Desalination would also be more cost-effective at larger scales between 150 to 200 million litres per day would be the best economy of scale for Cape Town.

6. What other constraints are there?
The availability of electricity is also a potential issue. Concerns have been raised in the United States that electricity supplies in local grids are not able to accommodate new desalination plants built in response to the Californian drought. South Africa is not long out of an electricity crisis. A further energy crisis at the same time as a water shortage would place this source at risk. Some plants overseas are starting to operate with solar energy, and this could be an option for Cape Town in the long-term. At the moment most of our energy is generated using coal-fired power stations and this means our energy generation puts a lot of greenhouse gases (GHGs) into the atmosphere which is a cause of climate change – which in turn would fuel future droughts.

9. How expensive is desalination compared to other water sources?
Globally desalination is between two to four times as expensive as most other sources depending on the relative cost of capital equipment (how much has to be imported etc), the cost of energy and the cost of labour to implement other water savings. By way of comparison the costs for Cape Town would be:

Raw surface water | between R1 and R4 per kilolitre
Alien clearing to release more water from our catchments | from R6 to R15 per kilolitre
New groundwater | around R15 per kilolitre
Reclaiming and re-using treated waste water | between R10 and R20 per kilolitre
Large-scale, permanent desalination | between R10 and R22 per kilolitre
Smaller, short-term desalination | R34 to R44 per kilolitre

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Monwabisi desalination plant starting side preparation – Cape Town – South Africa

The Monwabisi desalination plant is one of seven projects earmarked as part of the first phase of the City of Cape Town’s Additional Water Supply Programme. Site preparation is currently under way. “It is anticipated that the Monwabisi plant will produce a total of seven million litres of drinking water per day which will be fed into the water reticulation system to supplement current supply from the dams and other water sources. “A nine-week construction period is planned for the completion of the first phase comprising two million litres. The first drinking water generated by the desalination plant is expected to be fed into the reticulation system by March 2018 with the second phase of five million litres to follow on after a further nine weeks. “The plant is intended to operate for a period of two years, based on a service agreement in which the city has agreed to buy water from the service provider Water Solutions Proxa JV. The value of the tenders for the establishment and operation of the desalination plant at Monwabisi for a period of 24 months is R260m,” said the city’s mayoral committee member for Informal Settlements, Water and Waste Services; and Energy, Councillor Xanthea Limberg. Other projects include the Strandfontein, V&A Waterfront, and the Cape Town Harbour desalination plants; the Atlantis and Cape Flats Aquifer projects; and the Zandvliet water recycling project which will collectively produce an additional 196 million litres per day between February and July 2018. In addition, the city has 12 projects at an advanced planning stage. “There will be minimal risks to public health and safety, and work will comply with the applicable national health and safety regulations. All construction areas will be clearly demarcated and will be off-limits to the public. Any pipe work that is not underground will be clearly marked. The plant has been designed to ensure fast-tracked construction and production but with the smallest possible construction footprint. “The city will monitor the site and regularly test the drinking water that is produced. We are proud that the plant in Monwabisi will be our flagship desalination plant. We are truly grateful for the support of the community leadership and residents in this area. They will be true partners in this exciting and necessary development,” said the city’s mayoral committee member for Area East, Councillor Anda Ntsodo. In addition, the Strandfontein plant site preparation is set to commence which will also produce seven million litres of water per day when in full production. The evaluation of a tender for a temporary desalination plant on East Pier Road in the V&A Waterfront is in its final stages. This plant is to be located in an open-air parking lot opposite the heliports, and will produce two million litres of water per day.

Zille lauds management of Bitou’s desalination plant- Plettenberg Bay – South Africa

WESTERN Cape premier Helen Zille has lauded the design and management of Bitou’s desalination plant. She was in the area last Thursday to speak at the S-Cape Landowner’s Initiative’s Environmental Seminar 2017, and to inspect projects related to the Garden Route Rebuild Initiative. Talking about drought mitigation measures in Bitou, she said: “Roodefontein Dam is currently 72% full, and augmentation schemes in this municipality include equipping two new boreholes in Kurland, four in KwaNokuthula, and four in Uplands. “Drilling for these boreholes has already commenced, and we’re also planning two additional boreholes in Harkerville. After inspecting Plett’s desalination plant, Zille met with the town’s political and administrative leadership in the council chambers. “It was amazing to see a desalination plant in that beautiful location right next to the lagoon, and to see the technology at work,” she said. “Even more amazing for me was to see how you have resolved major technological problems that have been worrying – for example the way you handle the brine that can be toxic if it’s dumped near the coastline.” Bitou’s plant sends the brine out in plumes so that the wind blows it around, and wave action then churns so that absorption has no impact on the ocean. “This is exciting because it may be a technique we can use elsewhere in the province, rather than spending millions on pumping the brine far out to sea,” said Zille. “I was also fascinated to hear that you’re extracting water from a well point in the lagoon, because everything I’ve heard and read about desalination says that you have to extract the water from a clear open ocean space. “But here you’re allowing the sand to do half of the work by filtering it first, which also saves lots of money – as does your use of a turbine that saves 40% on your electricity bill. I’ve been very impressed, and I’ve learned a lot technically,” she said.

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Desalination: Cape Town’s solution to water shortages – South Africa

Minister of local government‚ environmental affairs and development planning in the Western Cape, Anton Bredell, says the province has been managing drought conditions in some parts of the region since 2010. “Three years of below-average rainfall have exacerbated the situation and despite proactive measures like the implementation of water restrictions and programmes to clear the Berg River of alien vegetation‚ the reality is we are faced with a dire situation.” Inspired by the Target 140 Campaign implemented in South East Queensland, Australia, Cape Town embarked on reducing water usage. So far residents’ water usage has dropped below 100 litres per person per day, making the City’s Water Conservation and Water Demand Management Programme one of the most successful water conservation projects globally – a fact recognised at the 2015 C40 Cities Awards in Paris. Mayor Patricia de Lille thanked Capetonians and commended them “for rising to the occasion to save more water in our City because we are determined that we will not allow a well-run City to run out of water”. The mayor told the media the City will run out of water by March next year, at current usage levels. Despite water restrictions and the water savings achieved, Cape Town still needs 450 megalitres of water a day. With no end to the drought in sight, the City has approved plans to build a desalination plant to turn salty sea water into potable water. Construction will begin in December at the V&A Waterfront, the first approved site. By February the plant will feed two million litres of water into municipal networks. The harbour site will allow the City to draw water from the harbour and pump the salt brine residue into the ocean. As David Green, V&A Waterfront chief executive officer, explained: “At peak we have about 7m tidal waves, which means that there is no issue in terms of marine life, the brine is cleared immediately.” The V&A plant is the first of a possible eight the City wants to build. Down from an original 17, the other sites include Dido Valley‚ Granger Bay, Harmony Park, Hout Bay‚ Monwabisi, Strand and Strandfontein. The plants will have a working life of two years and, it is hoped, will supply the City with up to 15 million litres of usable water a day…. (LINK)

Cape Town’s temporary desalination plants online ‘February 2018’ . South Africa – Cape Town

… After yesterday’s rains across the metropole, Cape Town mayor Patricia de Lille briefed media, and Twitter, on updates regarding its water resilience scheme. The scheme aims to “avoid a time when users do not have access to municipal drinking water”, de Lille explained. “In terms of our Water Resilience Plan to augment supply with schemes, we are expecting the first water to come online by Dec 2017 /Jan 2018,” she tweeted. The plan intends to add an additional 500-million litres per day to Cape Town’s water supply by using natural springs, aquifers, and desalination. The latter, however, won’t be ready this year. …

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Tender to produce extra 500Ml of water for Cape Town – South Africa

“Our intent is to both drive down collective usage to 500Ml per day and to ensure that there is always at 500Ml/day of water in production,” Mayor Patricia de Lille told reporters on Thursday. She said the city had decided to take the most pessimistic view of the drought, and hoped to have the first desalination plant on line by the end of October. The city had reduced water consumption from around 1000Ml a day in the past year to the latest figure of 610Ml a day. This was still too much, given the poor prospects of dams filling up anytime soon.

As of August 14, the average level of dams supplying the city was 31.1%, up 1.7 percentage points from the previous weeks. However, 10% of the dams’ water was unusable, leaving average levels at only 21%. There are currently severe water use restrictions in place, prohibiting the use of drinking water for anything other than cooking, drinking, and two-minute showers. De Lille said the city had accepted it was no longer feasible to just wait for the rain.

It had to start preparing for the “new normal” of regular water shortages because of climate change, and to stop relying solely on surface water.

The ambitious plan to produce the extra 500Ml would be rolled out in stages. … (LINK)

Cape Town’s first desalination plant – South Africa

Mother City residents could be drinking seawater by as early as August of this year. Great news, seeing as the recent rains – as heavy as they were – barely made a dent in the dam levels of the resources supplying the city, pushing them up to just over 23%.

Officials are hopeful that, as of August, Capetonians won’t be completely reliant on existing dams and reservoirs, what with an additional 500 million litres of desalinated water being pushed out per day.

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