Wedge Group

Background to specification
When East Anglian Galvanizing Ltd moved from Peterborough to nearby Sawtry, its new £6 million state-of-the-art plant was to boast industry-leading ‘green’ technology featuring an integrated rainwater collection and storage system. It is a major investment by parent company the Wedge Group, whose green credentials have always included a policy of stormwater retention.

Credit for the innovation goes to the construction contractors Watson & Cox, whose policy is to rationalise and develop the tender design throughout the process in order to provide the optimum solution to meet the user’s requirements.

Key criteria
When a crate system was originally planned by the developers, Watson & Cox’s contracts manager believed a better alternative lay in the multifunctional features of a steel tank, and was recommended by Hevey Building Supplies, Northampton’s largest independent merchants, to consult Tubosider, the leading UK manufacturer in the field.

The ultimate solution would be to simplify such a complex design by utilising a Tubosider 1.4m diameter pipe of just 325 m³ capacity to the building perimeter to form a combined attenuation tank and carrier pipe. This significantly reduced the volume of both traditional drainage and exported excavation material and provided substantial benefits to this critical element of the programme, including much greater ease of maintenance and the need for far fewer manholes.

Solution & benefits
The system now in operation enables large volumes of rainwater to be recycled into the galvanizing process, eliminating ‘run-off’ from the 2.5-acre site and minimising the use of mains water.

“Using this design we were able to connect the surface water drainage and roof drainage directly into the client’s 200 m³ tank, with a full retention separator downstream,” says the contracts manager. “Just as important, it saved us time. With the completion date fixed at the tender stage, keeping on schedule is a critical issue for contractors, and Tubosider’s tanks are easy to handle and come ready to install.”