The fresh water underground aquifer near Liwa Oasis in the Western Region, designed to ensure water supplies for the capital and all of the Western region in case of emergency, will be launched soon, officials have told the English daily, The National.

"We will start operations in August or September," said Dr Mohammed Dawoud, Water Resources Manager at the Environment Agency Abu Dhabi, EAD.

Construction of the project began in 2010, but was delayed because there had to be modifications in the design, said Dr. Dawoud.

According to The National, the site is already under testing with seven million gallons of desalinated water being pumped underground every day. In case of emergency, as much as 40 million gallons of water can be used from the reservoir in a single day. The aquifer should ensure emergency supply for 90 days.

Besides providing emergency storage, the daily said, Abu Dhabi has invested in improving its sewage collection network. Early next year, Abu Dhabi Sewerage Services Company, ADSSC, will commission an underground tunnel to take sewage from Abu Dhabi island and the surrounding areas to treatment plants in Al Wathba.

The project, which has been under construction since 2009 is part of the Strategic Tunnel Enhancement Programme, STEP.

"The main tunnel, which is consisting of 43 kilometres, is completed," said Omar Alhashmi, Projects Division Director at ADSSC. "Seventy percent of the link sewers, which are 53 kilometres, was also completed."

For the remainder of the year, work will be carried out to complete the pumping station, located at a depth of 100m. The project is expected to be commissioned between January and April 2016.

The new system will mainly rely on gravity to carry out sewage from the capital to treatment facilities in Al Wathba. This, said Mr Alhashmi, will reduce the amount of energy used throughout the system.

"The existing system is based on pumping and gravity, so once the tunnel is completed, we will decommission 34 pumping stations that are causing nuisance, odours, operational problems and power consumption," he said.

The daily noted that because of the increased energy efficiency of the new system, it is expected to save Dh231 million in electricity costs over the 80 years of design life for the tunnel. This would translate into 346,608 tonnes of carbon dioxide and other gases harmful to the climate not being released into the atmosphere.