The US Department of Energy has extended the contract for cleanup of the Hanford River Corridor Closure by one year.

The contract is held by the AECOM-led Washington Closure Hanford LLC joint venture, which also includes Bechtel and CH2M Hill.

AECOM, which acquired URS in 2014, said the extension is worth $148m and will run from 30 September 2015 until 30 September 2016.

The main focus of the work will be on completing the trench work at the 618-10 "burial ground" and placing the Chemical Materials Engineering Laboratory (Building 324) in a maintenance status for future demolition. Operations at the Hanford Environmental Restoration Disposal Facility will also continue, where over17 million tons of contaminated material has been disposed of since 1996.

"We are pleased to have been awarded this extension," said Randy Wotring, president of AECOM's management services group. "AECOM and our heritage companies have been successful in cleaning up more than 534 waste sites, demolishing over 323 buildings, and placing two plutonium-production reactors in interim safe storage along the Columbia River."

This extension covers work along Hanford's 220-square-mile river corridor.