WATER TREATMENT: Ras Abu Fontas A2 Seawater Desalination Plant is located at Ras Abu Fontas, about 10km south of Doha.

By Steff Gaulter

Despite the fact that the last time it rained in Doha was May 10, water flows whenever we open the tap. Obviously at this time of year that water is normally at a temperature that will boil your head, but it’s still free-flowing and that’s pretty impressive. Even though we live in a desert, we’re lucky enough to be able to take water for granted.
To have this supply of water readily available is even more impressive given that the country has an average rainfall of just 75 millimetres per year. This is not much rain at all, especially when you compare it to other cities: Sydney is inundated with 1,222 millimetres per year, Manila sees 2,201 millimetres and London, a relatively dry capital, receives 611 millimetres.
Having said that, Doha is by no means the driest capital city on earth. That award goes to the Peruvian capital of Lima which, despite being on the coast, only sees a pitiful 13 millimetres of rain in a year. You may have thought that being on the coast would encourage rain, but the water that wells up along the shore is a cold current, so it actually suppresses the rainfall and creates a desert all the way along the coast. However, despite its lack of rain, Lima manages to avoid having a permanent water crisis.
Lima’s free-flowing water is thanks to the huge mountain range, the Andes, which lies to the east of the city. The mountains receive plenty of rain and this water fills the rivers that sweep down to the coast. This rainfall, together with the melting glaciers, add to the river levels to ensure that water is not in short supply.
Closer to Doha, another city which has less rainfall than us is Cairo. The average rainfall is about 25mm per year, just a third of that Doha expects. There are water issues there, but they are alleviated by the huge River Nile. The quality of the water may be deteriorating as the river becomes more polluted, but it still provides the majority of the drinking water to the city.
In times gone by, Qatar was able to quench the thirst of the desert dwellers with its springs and groundwater supply, but not anymore. With over 2 million residents, Doha’s population is simply too big and it’s growing by the day. Without abundant rainfall, vast rivers, or melting glaciers, the only way that Doha can supply its population with water is using desalination, a way of taking the sea water and turning it into drinking water. This is the most expensive way of getting drinking water, as it takes such a vast amount of energy to separate out the salt, but in Doha, however, it’s our only viable option. Without desalination, Doha wouldn’t have a reliable water supply and therefore couldn’t exist in its current state.
It wasn’t that long ago that the Gulf’s first desalination plant began operation: 58 years ago in Kuwait. Since then, numerous desalination plants have opened across the Gulf region, but this isn’t the only part of the globe that finds it necessary to use desalinated water. There are now desalination plants in many other countries including Australia, USA, Cyprus, and Gibraltar. In fact there are now estimated to be over 15,000 desalination plants operating worldwide and over half are in the Middle East.
Desalination plants use a variety of methods to remove the salt from sea water, but all of them produce vast amounts of a waste material called brine. Brine is a mixture of hot salty water and chemicals, some of these chemicals are used in the separation process, and the others are used in the maintenance of the plant. Sea water is very corrosive, meaning that a lot of maintenance is required.
The amount of brine produced by a desalination plant is huge, and the vast majority of it is pumped directly back into the Gulf. It is estimated that as a result of the desalination plants in the Gulf, 23.7 tonnes of chlorine are flushed into the sea every single day, together with 64.9 tonnes of antiscalants and 296 kilograms of copper. It’s a wonder that the shallow little Arabian Gulf can support this.
How much damage this is doing to the Gulf is unknown, as few studies have been undertaken and generally the damage is masked by more immediate and obvious problems to ocean life, including oil and gas plants and land-reclaiming projects. It’s thought that we are helped by favourable mixing, which happens naturally in the Gulf. This helps to disperse the pollutants; chlorine decays very rapidly anyway, antiscalants are inherently biodegradable and the copper is assumed to be transported into the sediments.
Strangely the desalination process can only work if the original sea water is of a good and clean quality. Therefore it is essential that the waters of the Gulf do not become overly polluted and more studies are needed to investigate the impact of desalination. In the meantime, despite the fact that water is heavily subsidised here, perhaps we should all try to remember the true value of water. The next time you turn on the tap, just remember the Gulf— it needs to stay unpolluted for Doha to thrive.

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