Two engineers working to move the 250m blockage adapted processes from water and wastewater engineering to drill through the centre of the fatberg, using auger boring process. They then fed a steel rope line through the hole and hung an adapted jet machine normally used to clear sewer blockages.
The machine was moved around on the steel rope inside the fatberg to blast it away from the inside.
A protective UV-cured chemical resistant layer was applied to the inside of the sewer to prolong its life and prevent flooding issues from happening in the future.
Sammy Nelson, UU’s wastewater programme delivery manager, said: “Together we came up with the idea of using guided directional drilling equipment to drill through the fatberg and then allow a cable to be run through which would allow jetting to be carried out.
“We then reconfigured a cutting jet to run along the cable through the centre of the fatberg like a ‘Zip Wire’ – this was done to great success and within a couple of weeks flow was restored to the sewer.
Working with Sapphire Utility Solutions, the work was carried out in half the time it would have taken to replace the sewer system and at just over a third of the cost, Nelson said.
Fatbergs form when fats, oils and greases congeal within pipes, becoming hard and – with wet wipes and other unflushable items – create an obstruction.
The build-up of wet wipes in sewers and pipes makes up around 90 per cent of fatberg materials. This costs water companies millions of pounds each year to remove and causes flooding and pollution incidents.