Treated sewage will reduce Gulf water use

Move to offset dependence on costly seawater desalination and groundwater supplies in Abu Dhabi.

Plans are under way to increase water efficiency in agriculture, above, fit water-saving devices to residential and public buildings and cut "wasteful" landscape use

Abu Dhabi plans to introduce quotas on the use of treated sewage water for agriculture, landscaping and district cooling to help to reduce the amount of water removed from the Arabian Gulf. The emirate is among the world's highest consumers of water and the quotas are intended to improve its management of water.

Most of the emirate's water is desalined seawater, which is expensive to produce. This is supplemented by groundwater used for agriculture. The Government has identified treated water as a resource in its own right, said Majid al Mansouri, the secretary general of the Environment Agency-Abu Dhabi (EAD). The quotas will be discussed at the next session of the Permanent Committee for Water and Agriculture Resources, said Mr al Mansouri, although he was unable to give a precise date.

The committee was established in December and is chaired by Mohammad al Bowardi, the secretary general of the Abu Dhabi Executive Council. It is comprised of representatives of Government agencies including the EAD, the Abu Dhabi Food Control Authority and the Abu Dhabi Water and Electricity Company (ADWEA). Mr al Mansouri was speaking at a one-day forum in the capital, marking the second anniversary of the Arab Water Academy, and attended by ministers of water resources from Iraq, Sudan, Yemen and Saudi Arabia.

Mr al Mansouri briefed ministers on the emirate's efforts to better manage its water, including fitting water-saving devices in residential and public buildings, reviewing landscaping practices and increasing the efficiency of agriculture. The moves are an attempt to reduce Abu Dhabi's reliance on desalination, which incurs large financial and environmental costs. The high salt concentration of brine pumped back into the Gulf damages coral and the marine environment, research shows.

In 2007, the emirate's desalination plants produced a total of 856 million cubic metres of desalinated water. It costs around US$1 (Dh3.67) to produce one cubic metre of desalinated water, not including the cost of transportation. Saudi Arabia, another country that relies heavily on desalination, faces similar challenges. "If we continue with desalination use as we do today, we will be the biggest consumer of our own oil," said Dr Mohammed al Saud, the deputy minister for water at the kingdom's ministry of water and electricity.

In Abu Dhabi, it is agriculture that requires most water and, with forestry, accounts for 76 per cent of the emirate's water use. The use of treated sewage water to irrigate crops is illegal in Abu Dhabi. However, the technology exists to do this safely, and several trial projects are under way. Most public parks in the emirate are already irrigated by treated sewage effluent, but landscaping projects in the new private developments rely on desalinated water, said Geoff Sanderson, the principal landscape architect at Dubai-based Green Concepts.

"There has been a huge amount of waste in the past," he said, adding that inefficient irrigation systems and water-thirsty plants have made the sector inefficient. "There has also been too much landscaping in a country that can ill-afford the water needed for this," he said. "Abu Dhabi does not need all the shrubbery and grass. It is a total waste." Abu Dhabi city currently relies on a sewage treatment plant in Mafraq, where more than 450,000 cubic metres of waste water are treated daily.

A consortium, Al Wathba Veolia Besix Waste Water, is building two new plants, with a joint capacity of 430,000 cubic metres of sewage per day, in Al Wathba and in Allahamah, 40 kilometres from Al Ain. The project is due for completion in 2011, as is a further project to build two more plants with a joint capacity of 380,000 cubic metres per day, in Al Wathba and Al Saad, by a consortium including ADWEA, Emirates Utilities Company Holding and Biwater.