DUBAI // Abu Dhabi is wasting a huge amount of water that could be used to grow food, experts say.
A total of 600 million cubic metres of treated wastewater is produced a year, but only 352 million cu metres is reused for landscaping, district cooling and golf courses. The rest is dumped into the sea.
“Crops during the winter months in the UAE require less water but human consumption remains the same,” said Dr Nurul Akhand, an irrigation-management scientist at the International Centre for Biosaline Agriculture (ICBA) in Dubai.
“There needs to be a storage system set up in the winter months.”
And Abu Dhabi is not alone. Half of Al Ain’s treated wastewater is allowed to evaporate from lagoons and wadis, while Sharjah discharges 35 per cent of its into the sea.
“The population is increasing and consequently, so is the water consumption,” said Dr Akhand. “It’s a great resource and we need to utilise it.”
He was speaking at a training workshop on water use this week.
The UAE’s water consumption is among the highest in the world, at 350 litres a person a day.
“This is not just because of [residents] consuming water, it’s used on irrigating their gardens and washing their cars,” said Dr Akhand. “Other countries in Asia, for instance, use much less.”
Treated wastewater is far cheaper to generate than desalinated water.
“The aim is to be able to produce 1,400 million cu metres of treated wastewater by 2030,” said Dr Akhand.
Wastewater goes through several stages before it is fit for use, removing large solid lumps, then smaller and suspended solids.
The UAE treats it to a third level, removing nutrients and heavy metals. This can be used to irrigate inedible crops.
“The fourth level, which is a higher quality, was reached by Kuwait, where they are producing lettuce, and Bahrain,” said Dr Akhand. “It is economically justifiable to use treated wastewater in agriculture, so why not use it?”
Treated wastewater is far cheaper than desalinated water – Dh5.5 a cu metre compared with Dh9 – so to avoid wasting it, Abu Dhabi Sewerage Services has invested Dh1 billion in pumping stations and pipes.
“It is 95 per cent complete,” said Alan Thomson, the managing director. “Once finished, we will be able to take water to different areas where there is none at the moment and that will enable us to ensure the maximum amount is used.”
Mr Thomson said projections showed demand for the water exceeded the supply, “so we should be able to utilise very close to 100 per cent of it”.
Although the infrastructure is expected to complete by the end of the year, other companies that deal with wastewater must build their own to ensure no more water is dumped. Even then, there is a problem with perception.
“It is considered acceptable to use treated wastewater for amenities and landscaping,” said Dr Akhand. “But we found from a recent survey by ICBA that all farmers had a negative response. A very limited number of farmers use reclaimed water.”
And although authorities realise they have a way to go before the public is happy with the idea, the water savings will be worth it.
“It is difficult for the public to accept but it is [crucial] for us to save water here,” said Dr Mohamed Dawoud, the manager of water resources at the Environment Agency – Abu Dhabi.
“We should consider treated wastewater of good quality as an important resource.”
The agency is launching a pilot project next month to start using treated wastewater on edible crops.
“If it proves successful, we will extend it to other farms in Abu Dhabi,” said Dr Dawoud.
And Dubai is following closely as ICBA has planned to meet with the municipality’s irrigation department this month to introduce the concept.
“Policymakers visited Singapore in the past to find out how they are using treated wastewater, and people are becoming more cautious so I’m expecting the situation to improve ,” said Dr Akhand.