Leading German group Bauer Environment said one of its units has been awarded a major contract by Petroleum Development Oman (PDO) to expand the world’s biggest industrial constructed wetland in the sultanate.

As per the deal, Bauer Nimr, a major provider of water treatment solutions, will be responsible for designing, constructing and operating the plant until 2044, reported the Muscat Daily.

Construction will be finished by the end of 2019, after which Bauer will operate the plant on a 25-year basis, it stated.

The innovative wetland treatment technology is unique in utilising gravity-flow and natural processes to remove a heavy load of hydrocarbons from the water.

The facility is remarkable for its size. In addition to the excellent treatment performance, with the hydrocarbon content in water being reduced to below 0.5 ppm at the outlet of the wetlands, almost 95 per cent of the crude oil entering the facility is recovered without the use of electricity or chemicals, said the report.

Following an expansion in 2014, 115,000 cu m can now run through the plant every day. The commissioned expansion will now see the plant’s capability being expanded by 60,000 cu m per day to reach a total capacity of 175,000 cu m per day.

The plant's first stage was completed in 2011 by Bauer, said the report.

The flagship project for treating contaminated water from oil extraction in the sultanate in Nimr has won numerous international awards for excellence in sustainability, innovation and safety, it added.