The ¥40bn ($363m) contract also covers the construction of pipelines which will deliver treated sewage effluent to the capital for irrigation.

With a capacity of 439,000 cubic metres a day, the Doha North plant will be the largest of its kind in Qatar and will be able to serve a population of more than 900,000 people.

Singapore-based Keppel Seghers won the $1.5bn design, build, operate contract for the main wastewater treatment plant in September 2007 (MEED 27:9:08).