The largest ultrafiltration (UF) and reverse osmosis (RO) desalination plant in Saudi Arabia is to be built for Marafiq, the country's leading water and electricity services operator, by Veolia Water.

With a capacity of 178,000 m³/d, the plant will supply the Sadara petrochemical complex built by Dow Chemical and Saudi Aramco in Jubail Industrial City II and is due to come on stream in June 2015. The water will be used in two cooling towers and as boiler feed water.

The contract will generate US$ 310 million in revenue for Veolia Water for the plant's design and construction, and US$ 92 million in revenue for its operation for 10 years, with an option to extend the contract for a further 20 years.

To meet the very strict water quality standards required by Marafiq and minimize the impact on the environment, Veolia Water, through its subsidiary Sidem, has designed a plant to limit the risk of plant failure and extend its lifespan, while at the same time reducing the site's energy requirements and costs.

After an initial treatment phase involving dissolved air flotation - to capture the suspended particles in the water - and UF, the water will then be desalinated by RO membranes before being remineralized.