Client: Laing O’Rourke
Services: Temporary works design, supply and installation of ground support system

Project Omega is one of the UK’s largest Public Private Partnership (PPP) schemes providing a fifth of Northern Ireland’s wastewater treatment capacity. It also handles the entirety of its sludge disposal. The scheme is intended to form a sustainable wastewater strategy to meet the Province’s needs for the next 25 years.

The project included upgrading six existing wastewater plants – at Ballynacor, Bullays Hill, Seagoe, Armagh, Richhill and Ballyrickard – refurbishing a number of sludge facilities and constructing three pumping stations and associated transfer pipelines. The project cost was £122m – strong competition throughout the tendering process and the high degree of innovation encouraged by the PPP performance criteria having yielded savings of more than 17% of the original £154m capital estimate.

Working for Laing O’Rourke, Trench Control designed and installed a large cofferdam as part of the upgrade of Ballyrickard Wastewater Treatment Plant. The cofferdam included 10m long sheets standing in cantilever (unpropped) and a scheme of ground anchors as the anti-floatation mechanism.