August 2006

Design completed for 50 Mld RO desalination plant

ACWA Emirates LLC, a subsidiary of Skipton (UK)-based ACWA Services, has completed the detailed design for a $90 million order to build two identical Seawater Desalination Plants on the crown of the prestigious "Palm Jumeirah" - the palm-shaped development created off the coast of Dubai (UAE). The contract was awarded to ACWA by Palm Water, the utility company for the development.

The two new desalination plants - scheduled for completion in 2007 - will produce 32,000m3/day of high quality drinking water for the residents of luxury villas and apartments and visitors to the hotels and leisure facilities currently being constructed on what is often referred to as "The Eighth Wonder of the World". The island is the first of three to be established in the area to increase Dubai's shoreline by 120km (72 miles) and create a large number of residential, leisure and entertainment areas.

The ACWA desalination plants will include screening, ultra-filtration, reverse osmosis, second stage R/O polishing, disinfection and remineralisation processes, designed to turn raw, saline seawater into high quality water supplies for residential consumption and a variety of island service facilities.

The optimal process design, delivered by ACWA, was required to overcome a number of challenges: In the early years of operation, Palm Jumeirah will still have substantial construction activities and it is probable that raw water drawn from the sea will be variable in quality. The ACWA design uses specially selected water quality monitors in the intake structure to provide early warning of changes in raw water quality and allow necessary operational adjustments to the treatment process.

Reverse Osmosis membranes are at the heart of the desalination treatment process and their reliability and working life is dependent on the effective pre-treatment of the raw water. This will be achieved by the use of Ultra Filtration membranes - a breakthrough on plants of this size that offers clear benefits over more conventional technologies. Twelve trains of ultrafiltration will be provided, including around 10% potential redundancy. The UF system will protect the RO membranes and ensure that the seawater characteristics are suitably adjusted for RO treatment. The design capacity will be achieved with duty UF units only and will include down-time (non-production time) for periodic, automatic cleaning and integrity testing. The units are arranged in such a way that total production is maintained without the need for a standby UF unit.

Giving special consideration to rising energy costs, the plant will include equipment to recover energy from the reject brine stream. The Energy Recovery System will transfer energy at high efficiency from RO plant brine to the low-pressure UF filtrate feed pumps.

Well satisfied with what is one of the the Company's highest value orders since its inception in 1986, ACWA's Managing Director, Peter Ripley, commented: "We are delighted to be associated with The prestigious Palm Jumeirah project. For us it is a continuation of the many successful R/O plants which ACWA has designed and installed for water companies and private enterprise throughout the UK and in many parts of the Middle East - particularly in arid regions where potable water is in extremely short supply. We are honoured to be part of such an internationally significant project, instigated to provide sustained economic expansion for Dubai and helping further enhance its position as a premier tourist destination. Since the establishment of our Dubai office in July 2004, business has been brisk and we now have over 20 people permanently based there."