Cape Town Builds Temporary Desalination Plants As Water Supply Approaches ‘Day Zero’

Written by Peter Pedroncelli

The South African city of Cape Town is in the process of building a number of temporary desalination plants in response to the water crisis that was brought on by three years of record drought in the region.

The popular tourist destination is in a race against time to produce solutions that will keep the taps from running dry in April – a date which has been described by those dealing with the crisis on the ground as ‘day zero’.

In 2015 South Africa recorded its lowest annual rainfall since record keeping began in 1904. While much of the country recovered from that particular year of drought conditions, Cape Town’s Western Cape province continued to experience extremely poor rainfall in recent years, leading to this water crisis.

Among the numerous efforts that are being undertaken to deal with the severe water crisis, the construction of temporary desalination plants continues in a rush, and the plant at Strandfontein Pavilion is on schedule, according to News24.

Desalination is the the process of removing salt from seawater in order to make it suitable for drinking.

The Strandfontein Pavilion plant, which will cost $19.8 million to build, will start producing the first 528,000 gallons (two million litres) of an expected 1.85 million gallons (seven million litres) per day in March.

Three desalination plants are expected to start producing water from that month, and tenders for three additional desalination plants are being considered by the city.

This is expected to assist in temporary relief from the water crisis, until the rains return and water supply can be re-established.

Water restrictions

Tight water restrictions have been imposed on residents in Cape Town for many months, with limits on the amount of water that can be used per person.

Level 6B water restrictions were implemented on Feb. 1, which means that Cape Town residents can only use 13.2 gallons (50 litres) per person per day as a means to avoiding ‘day zero’, according to ENCA.

For the sake of comparison, the average American uses between 80-100 gallons per day, the U.S. Geological Survey estimates.

Current projections by the city’s water crisis team suggest that ‘Day Zero’ will now take place on 16 April, 2018, unless tactics such as the desalination plants can produce effective solutions until winter rains which will hopefully arrive in the months of June, July and August.

Cape Town mayoral committee member for water, Xanthea Limberg, explained the reasoning behind making temporary desalination plants part of the overall solution.

“Given the severity of the drought and the uncertainty around rainfall, we needed to be flexible in our approach and allow for both permanent and temporary solutions in order to ensure that we minimise any risk of acute water shortages,” Limberg said, according to AllAfrica.

Desalination plants in Africa

The Strandfontein plant involves a two-year contract, after which time the plant will be removed and the area rehabilitated. Desalination in this case therefore represents a temporary solution.

The plant will pull water from around 0.6 miles out at sea through a pipeline, before it is filtered through reverse osmosis which will split the sea water into half clean water and half brine, which will be returned safely to the ocean.

South Africa’s 1,860-mile coastline could support a whole fleet of eco-friendly desalination plants, and it stands to reason that desalination technology could provide a long-term solution to the country’s water shortage issues.

South Africa is the main user of desalination technology in sub-Saharan Africa, while Algeria is a North African example of how desalination can be used on a large scale.

Mossel Bay in the Western Cape is the site of South Africa’s largest desalination plant, with drinkable water supplied to state oil company PetroSA’s gas-to-fuel refinery.

Ghana and Namibia also have operational plants. In April 2015, West Africa’s first desalination plant opened in Ghana, with the Accra Sea Water Desalination plant providing fresh water for 500,000 residents in the Accra vicinity, WaterWorld reported.

The Arabian Gulf region is home to the world’s main producers of desalinated water. In 2008 they were collectively producing about half of the global total, but only around one percent of the world’s population is dependent on desalinated water, according to TheConversation.

This is expected to increase to about 14 percent by 2025, and if Cape Town’s situation is an indication of global warming’s acceleration of water scarcity, desalination may be an important technology for African countries to embrace in the near future.

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