NRS Completes Major Land Remediation Project at Harwell

Nuclear Restoration Services (NRS) has completed its largest ever land remediation project, restoring 4.2 hectares of land at its Oxford-based site. The work followed more than 60 years of liquid effluent treatment operations at the former Liquid Effluent Treatment Plant (LETP) and neighbouring Sewage Farm Area.

More than 97,000 tonnes of material were removed during the project. The work involved tackling an extensive network of buried tanks, pipelines, pumping stations, reinforced concrete structures and treatment infrastructure, some located up to 10 metres below ground.

The LETP was constructed in 1948 to treat liquid waste generated by Harwell’s pioneering nuclear research programmes. At its peak, active and trade drainage systems from across the site flowed to the facility, where waste was treated before being safely discharged through a dedicated pipeline to the River Thames. The plant also handled higher activity liquid waste, supporting decades of scientific research and innovation at Harwell.

The former Sewage Farm Area had an even longer history, originally constructed in the 1930s to serve RAF Harwell, and later expanded as the site developed. Following the end of LETP operations in 2013, attention turned to safely decommissioning the ageing facilities and restoring the land.

NRS also created a new Sustainable Drainage System (SuDS) pond within the former Sewage Farm Area, providing a natural way to manage surface water while also creating new habitat for wildlife. Material generated during construction of the pond was reused to reprofile the former LETP area, avoiding the need to import approximately 60,000 tonnes of material and preventing an estimated 2,700 vehicle movements.

Public access has been restored to Icknield Way, a designated public bridleway alongside the former LETP area which had been temporarily inaccessible while remediation was under way. Gary Reid, Harwell Site Director, said the restoration supports the wider Nuclear Decommissioning Authority (NDA) mission to safely and sustainably clean up the UK’s nuclear legacy while releasing land for reuse wherever possible.