Work on the new outfall pipe at Swaleciffe Photo: Southern Water
Southern Water has completed the controlled sinking of a new outfall pipe nearly one kilometre long at Swalecliffe on the North Kent coast near Whitstable.
The engineering feat followed work by a specialist dredger, called the ‘Razende Bol’ and excavators working on the beach which involved digging a trench that runs from Swalecliffe Wastewater Treatment Works out into the North Sea.
The new pipe was manufactured in Norway in two parts, each approximately 500m in length and were towed across the North Sea, to a port on the Medway where it was harboured until the trench was ready. The new pipe arrived from the Medway port, was guided into position above the trench and valves were utilised to ‘sink’ the pipe into place and backfilled to cover it up.
The pipe is made of High-Density Polyethylene, has an internal diameter of just over a metre and will be almost a kilometre from the sea wall to the end of pipe, making it approximately 410m longer than the existing sea outfall pipe.
John Penicud, Director of Wastewater Operations at Southern Water said:
“The Swalecliffe engineering project will replace a sea damaged outfall pipe, as part of a major upgrade of its wastewater treatment works and a regulatory requirement, it will allow teams to install a much longer pipe in its place.”
Southern Water explained that ‘outfall pipes’ stop homes and businesses from being flooded. They are used as a last resort during and after heavy rainfall when storm tanks are full. This means any releases of stormwater from this outfall happen rarely. The new outfall pipe is further out to sea and further from local beaches and bathing waters.
They say this urgent work will take place alongside ongoing efforts by our Clean Rivers and Seas Task Force to drastically reduce our use of storm overflows like this one. These efforts, rolling out innovative nature-based and engineering solutions to this historic network of pressure release valves, are happening in the Swalecliffe area and throughout the region with a range of partners.
However, Southern Water say it will continue to work with partners to reduce the need to use the new outfall at all, by ensuring more rainwater stays in the environment and doesn’t enter the sewer network.
Watch the animation of the pipe install New outfall at Swalecliffe (southernwater.co.uk)