Limavady WwTW, Co. Londonderry

The Doran Consulting/ BSG/ WIS JV successfully completed this new extended aeration Wastewater Treatment Works for NI Water, on the site of the existing works on the outskirts of Limavady, adjacent to the A2 bypass. The scheme increased the treatment capacity of the works to 16,500 pe, providing for the expanding population and growing tourism industry, up to the year 2022.

In addition to population growth, the extension of the works was necessary to improve the quality of treated sewage and ensure that the quality of the water entering the River Roe is of an acceptable standard and meets the Urban Waste Water Treatment Regulations (Northern Ireland) 1995 and the revised discharge standards set by the Northern Ireland Environment Agency, thus preserving the area's natural beauty and flourishing wildlife.

The project included the construction of a new Inlet Works, Inlet Pumping station, Activated Sludge Plant, Storm Water Holding Tanks, Sludge Holding Tanks, Final Settlement Tanks and a new Control Building for process control equipment and sanitary provision for operators.

Our team adopted a sustainable approach to this Design & Build scheme by refurbishing and reusing existing assets where it was viable to do so, for example the original Primary Settlement Tanks were refurbished and re-used as Final Settlement Tanks in the new development. Poor ground conditions at the site necessitated the use of piled foundations, although the base of the original control building provided an adequate base for the new odour control facilities.