Contract awarded to local-international joint venture

Dubai, 01 April 2007

Based on the instructions of His Highness Sheikh Mohammed Bin Rashid Al Maktoum, Vice President and Prime Minister of UAE, and Ruler of Dubai, with regard to providing a modern infrastructure for the city and ensuring implementation of the Dubai Strategic Plan, Sheikh Hamdan Bin Rashid Al Maktoum, Deputy Ruler of Dubai, Minister of Finance and Industry and Chairman of Dubai Municipality has approved a project worth Dhs1.5 billion to construct a new Sewage Treatment Plant in Jebel Ali.

The Dubai Municipality has signed on Sunday a contract in this regard with the joint venture of local contractor, Al Ahmadiah-Aktor LLC, and Greek contractor, Aktor SA, for the construction of this 300,000 cubic meter per day wastewater treatment facility.

The contract was signed, in a ceremony on Sunday at DM premises attended by Sheikh Hashr Bin Maktoum Al Maktoum, Director of Dubai Information Department, Hussain Nasser Lootah, Acting Director General of Dubai Municipality, and Dimitris Kallitsantsis, Managing Director, Aktor.

Mr. Lootah said the contract constitutes the first phase of the new Jabel Ali Sewage Treatment Plant (STP) Project which has a projected capacity of 1.1 million cubic meter per day. This capacity will be built up over a number of phases which will be sized and programmed to suit the growth in wastewater flows produced by the ongoing and future developments of Dubai. The new plant is to be built on a 675 hectare desert site located south-east of the Jebel Ali Free Zone.

"This contract follows a comprehensive, two-year review of wastewater treatment technology and process design undertaken by the global environmental consultant, MWH, on behalf of the Drainage & Irrigation Department," Mr. Lootah said.

He noted that the main objective of the project is to provide the Emirate of Dubai with the best sustainable, environmental and economical wastewater and sludge treatment solution to supplement the existing treatment plant at Al Awir in meeting present and future treatment requirements.

"Key to meeting future requirements is the flexibility to keep pace with the dramatic population growth anticipated for Dubai over the next 25 years. To this end, the new STP has been designed to incorporate sustainable reuse of both final effluent, through municipal and agricultural irrigation systems, and sludge as a soil conditioner or fertiliser. Extensive odour control measures are also included to ensure low environmental impact principally with no odour nuisance. Value engineering has been used to rationalise costs while fast track construction will be employed to enable the new works to treat flows within two years, i.e. by mid 2009," Mr. Lootah said.   

In addition to the above, the location, desert conditions and size of the plant required raised a number of other design considerations. These included in particular issues such as high ambient air and wastewater temperatures, highly septic sewage, high levels of wind-blown sand and the need to meet the required treated water standard for un-restricted effluent re-use.

The treatment technology adopted to meet the requirements at Jabel Ali STP comprise conventional nitrifying activated sludge with tertiary filtration and disinfection for the liquid stream, mesophilic anaerobic digestion with thermal drying for the sludge and bioscrubbers with wet chemical scrubbers for odour control. The designs involve some new and challenging technologies such as conventional activated sludge employing a modified Ludzack-Ettinger (MLE) reactor; nitrogen removal plant; ultra violet disinfection - this will be one of the largest UV plants in the world; tertiary filtration to achieve less than 2NTU; thermal drying; odour control utilising a pre-venturi scrubber, bioscrubbers  with two stage caustic scrubbers for back-up.  

Significant add-ons to the treatment plant include tanker reception stations for both domestic and trade wastes, together with effluent storage and pumping facilities which will feed directly to the irrigation network.  

Designed to achieve the stringent quality standards laid down internationally for unrestricted public access irrigation, the wastewater treatment process will produce a treated effluent suitable for irrigation of public parks, landscapes, golf courses, playing fields in addition to road verges. The effluent criteria adopted comprehensively meets the requirements of the World Health Organisation.

As with most wastewater treatment facilities around the world, odour control is a very important issue, therefore the design criteria was set to ensure the new plant would not cause an odour nuisance beyond the boundaries of the STP site.  Odour modelling showed that a high level of odour covering and gas treatment was required, resulting in the process  units up to the activated sludge mixing chamber being covered along with all elements of the sludge treatment process.  The works involved in odour control include extensive airtight covers and ducting; Venturi scrubbers with 2 stream bioscrubbers; 2 stage caustic scrubbers, caustic storage and a discharge stack.

Essential to the functionality of a major treatment plant are the administration and control facilities. These works include the administration building and laboratory; accommodation block and welfare facilities for 150 staff; mosque; workshop and stores; tanker reception; sludge drying; blower houses; electrical transformer, generator, MCC and sub-station buildings; guard houses.

In general terms, the construction works will consume approximately 160,000 cubic meters of concrete, 27,000 tonnes of reinforcing steel and 70,000 square meters of GRP protective lining.

The construction period for completion of the Phase 1 works is 3 years. However, to enable wastewater flows to be treated early, a reduced stream of capacity 150,000 cubic meters per day is to be fast tracked and commissioned within 2 years of contract award.  This advanced stream will incorporate the tanker reception facilities and inlet works in full, with the pre-aeration, primary settlement, MLE reactors, final settlement, filtration, disinfection, sludge, odour controls and associated works being scaled down accordingly. The remaining site, process and building related works would be completed as part of the second 150,000 cubic meters per day stream for commissioning and handover by the end of third year.

-Ends-

Thajudeen V. Aliar
Journalist,
Public Relations & Organisations Dept.
Dubai Municipality.
Tel  +971 4 2064609
Fax  +971 4 2232188
Email: tvaliar@dm.gov.ae

© Press Release 2007