DUBAI // While you wouldn’t necessarily want to drink a glass of it, the water that shoots more than 150 metres into the air from the Dubai Fountain is so clean that even on the hottest summer day no algae will form in the lake.
The purity of the 166,238 cubic metres of water in the man-made lake might not ever occur to any of the thousands of tourists who come to watch the fountain show each day, but for the team of people who work behind the scenes, it is essential to keeping the attraction’s four underground filtering stations working around the clock.
Herve Faujour, technical and performance manager Middle East at Veolia Environnement, the company that built the system, moved to the UAE in 2007 specifically to work on the Dubai Fountain, which is the largest choreographed fountain display in the world.
“I came to the UAE to build this plant,” he said. “I did the proposal [in 2006] when I was working in Paris and when we got awarded [the contract] I decided to move to Dubai to execute the project, so to me it is very special. It is my baby, somehow.”
Work to build the fountain was completed in 2010, when the filtering stations were installed below ground adjacent to the lake’s shore.
The total cost of the fountain, lake and filtration system was Dh800 million. The 275-metre-long fountain shoots water to heights of more than 150m and it is about 25 per cent larger than the famous fountain at the Bellagio, in Las Vegas.
Each filtering station measures seven metres by 35 metres, and they stand seven metres tall. They had to be designed to take up as little space as possible, while also keeping noise to a minimum so as not to upset customers at the numerous restaurants and cafes above.
Even though each station treats enough water to quench the thirst of 100,000 people a day, they are small in size, said Mr Faujour.
“Normally, this would be 10 times bigger,” he said.
Initially, the 1.3m-deep lake was to be filled with potable water, but that idea was scrapped.
“As it operates, water would evaporate through the sun and through the fountain so we need to top it up,” said Mr Faujour, explaining that the losses average about 1,000 cubic metres a day.
“We have some sensors in the lake and when we see the level starting to go down, we top up until it goes back to normal,” he said.
Treated sewage effluent, produced by a treatment plant servicing the entire Downtown Dubai area, is used to top up the lake. Treated rain water is also collected and pumped back into the lake.
To ensure that it remains clean, the lake’s water is continuously circulated through the four filtering stations where dust, debris, dissolved impurities and algae are removed.
In the first stage, the process relies on gravity to settle some of the impurities to the bottom of a holding tank.
Chemicals such as aluminium salts are added to help bind dissolved impurities together so they can be removed more easily.
The water is also passed through filters that capture particles as small as 10 microns, 100 times smaller than a millimetre.
Finally, chemicals such as concentrated bleach, copper and some chlorine are added to suppress algal growth.
Even though it is highly treated, the water would eventually grow algae if it were to remain stagnant for a long time. To prevent this, each station has a 30-kilowatt electric pump that ensures the movement of water through the system.
While some may question the environmental message behind creating a large water feature in the desert, for Mr Faujour, the project’s value lies in the fact it does not rely on potable water.
“This is an interesting example of reusing,” he said.